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Sample records for capacitated dynamic lot

  1. Capacitated Dynamic Lot Sizing with Capacity Acquisition

    DEFF Research Database (Denmark)

    Li, Hongyan; Meissner, Joern

    model which combines the complexity of time-varying demand and cost functions and that of scale economies arising from dynamic lot-sizing costs with the purchase cost of capacity. We propose a heuristic algorithm that runs in polynomial time to determine a good capacity level and corresponding lot...

  2. Competition under capacitated dynamic lot-sizing with capacity acquisition

    DEFF Research Database (Denmark)

    Li, Hongyan; Meissner, Joern

    2011-01-01

    Lot-sizing and capacity planning are important supply chain decisions, and competition and cooperation affect the performance of these decisions. In this paper, we look into the dynamic lot-sizing and resource competition problem of an industry consisting of multiple firms. A capacity competition...... model combining the complexity of time-varying demand with cost functions and economies of scale arising from dynamic lot-sizing costs is developed. Each firm can replenish inventory at the beginning of each period in a finite planning horizon. Fixed as well as variable production costs incur for each...... total capacity demand of all the competing firms. We solve the competition model and establish the existence of a capacity equilibrium over the firms and the associated optimal dynamic lot-sizing plan for each firm under mild conditions....

  3. Optimal Method of Capacitated Lot-Sizing Planning in Manufacturing Systems

    Institute of Scientific and Technical Information of China (English)

    CHANG Jian-feng; ZHONG Yue-xian; HAN Zan-dong

    2006-01-01

    This paper analyzes the capacitated lot-sizing problem considering an individual machine's production capacity using a two-layer hierarchical method to minimize the sum of the dynamic inventory cost and the overtime penalty cost.The genetic algorithm,the parameter linear programming method,and a heuristic method were used in the developed methOd.The method uses the genetic operator to define the lot-sizing matrix(the first layer),linear prograrnming to determine each machine's schedule(the second layer)according to the lot-sizing matrix,and the heuristic method to verify the feasibility ofthe solutions by adiusting them to meet the constraint requirements.The scheduling of machines in a press shop demonstrates the effectiveness Of the algorithm.The result shows that the algorithm is convergent.

  4. Capacitated dynamic lot sizing with capacity acquisition

    DEFF Research Database (Denmark)

    Li, Hongyan; Meissner, Joern

    2011-01-01

    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...... 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. For this...

  5. Modeling of Multi-Level Capacitated Lot-Size Scheduling Problem

    Directory of Open Access Journals (Sweden)

    Zuhaimy Ismail

    2011-01-01

    Full Text Available Problem statement: Lot-size is the clustering of items for transportation or manufacturing processes occurring at the same time. The issue in lot-size problem is to design production processes so that the feasible production quantities are equal to customer demand quantities and the timing of production is such that inventory positions are almost zero. Approach: In this study, we explore the multi-level lot-size and scheduling problem. It is on a multi-level capacitated lot-size problem or known as the multi-level lot-size problem with bottlenecks. Two models were introduced to solve the multi-level lot-size problem namely the Billington model and Alf Kimms model. Using these models, a simple heuristic method was designed to solve a multi level capacitated lot sizing scheduling problem. Results: In this study, we showed that Alf Kimms model is more efficient than Billington model. The result given by Alf Kimms model is always feasible without further modification unlike the Billington model. This is due to the way the constraint is devised to ensure the inventory balance. The constraint used in Alf Kimms model ensures that inventory in hand is always sufficient to fulfill the demand occurred in each period. However, the use of this constraint in Billington model is to ensure that the total production for each item is always greater than or equal to the total external demand in the time horizon. Therefore, without some form of modification, the result given by Billington model will be infeasible production plan. Conclusion: A comparative study between these models shows that both models were successfully devised to solve capacitated multi-level lot sizing problem with the objective function to minimize the total holding costs and setup- cost. This study also shows that the production schedule will always start at the last period because this will give the lowest costs and it also shows that Alf Kimms model gives a set of

  6. A new approach for solving capacitated lot sizing and scheduling problem with sequence and period-dependent setup costs

    OpenAIRE

    Imen Chaieb Memmi; Sondes Hammami Laaroussi

    2013-01-01

    Purpose: We aim to examine the capacitated multi-item lot sizing problem which is a typical example of a large bucket model, where many different items can be produced on the same machine in one time period. We propose a new approach to determine the production sequence and lot sizes that minimize the sum of start up and setup costs, inventory and production costs over all periods.Design/methodology/approach: The approach is composed of three steps. First, we compute a lower bound on total co...

  7. Cellular Manufacturing System with Dynamic Lot Size Material Handling

    Science.gov (United States)

    Khannan, M. S. A.; Maruf, A.; Wangsaputra, R.; Sutrisno, S.; Wibawa, T.

    2016-02-01

    Material Handling take as important role in Cellular Manufacturing System (CMS) design. In several study at CMS design material handling was assumed per pieces or with constant lot size. In real industrial practice, lot size may change during rolling period to cope with demand changes. This study develops CMS Model with Dynamic Lot Size Material Handling. Integer Linear Programming is used to solve the problem. Objective function of this model is minimizing total expected cost consisting machinery depreciation cost, operating costs, inter-cell material handling cost, intra-cell material handling cost, machine relocation costs, setup costs, and production planning cost. This model determines optimum cell formation and optimum lot size. Numerical examples are elaborated in the paper to ilustrate the characterictic of the model.

  8. Record Dynamics and the Parking Lot Model for granular dynamics

    Science.gov (United States)

    Sibani, Paolo; Boettcher, Stefan

    Also known for its application to granular compaction (E. Ben-Naim et al., Physica D, 1998), the Parking Lot Model (PLM) describes the random parking of identical cars in a strip with no marked bays. In the thermally activated version considered, cars can be removed at an energy cost and, in thermal equilibrium, their average density increases as temperature decreases. However, equilibration at high density becomes exceedingly slow and the system enters an aging regime induced by a kinematic constraint, the fact that parked cars may not overlap. As parking an extra car reduces the available free space,the next parking event is even harder to achieve. Records in the number of parked cars mark the salient features of the dynamics and are shown to be well described by the log-Poisson statistics known from other glassy systems with record dynamics. Clusters of cars whose positions must be rearranged to make the next insertion possible have a length scale which grows logarithmically with age, while their life-time grows exponentially with size. The implications for a recent cluster model of colloidal dynamics,(S. Boettcher and P. Sibani, J. Phys.: Cond. Matter, 2011 N. Becker et al., J. Phys.: Cond. Matter, 2014) are discussed. Support rom the Villum Foundation is gratefully acknowledged.

  9. 蚁群算法在单级多时段多资源约束的生产批量问题中的应用研究%Application of an Improved Ant Colony Optimization Algorithm for Solving Single-level Multi-period Capacitated Dynamic Lot-sizing Problem

    Institute of Scientific and Technical Information of China (English)

    李英俊; 陈志祥

    2012-01-01

    One algorithm structure of an ant colony optimization(ACO) for solving multi -periods continuous and mixed integer programming problem was first designed herein and then its application in the single-level multi -period capacitated dynamic lot-sizing problem(CLSP) was introduced. The algorithm was based on the model characteristics of CLSP and improvements of traditional ant colony algorithm. Compared with other algorithms of other literature, the algorithm presented herein performs better than that the traditional genetic algorithm and the hybrid of simulated annealing penalty and genetic algorithm do;it has higher ability of obtaining optimal value. The application results show the method is feasible and effective for solving this kind problem.%设计了一个用于求解具有多时段连续与整数混合规划问题的算法结构,并以单级多时段多资源约束的生产批量问题(CLSP)的模型为背景进行了应用研究,根据此类问题的特点设计了新颖的蚁群算法,阐明了算法的具体实现过程.通过对其他文献中的例子进行计算和结果比较,表明提出的改进蚁群算法在寻优方面比退火惩罚混合遗传算法和传统的遗传算法要好,验证了所提算法对解决此类问题的可行性和适用性.

  10. Parallel ant colony algorithm and its application in the capacitated lot sizing problem for an agile supply chain

    Institute of Scientific and Technical Information of China (English)

    李树刚; 吴智铭; 庞小红

    2004-01-01

    In order to study the capacitated lot sizing problem for a supply chain of corporate multi-location fac-tories to minimize the total costs of production, inventory and transportation under the system capacity restriction and product due date, while at the same time considering the menu distributed balance, the mathematical pro-gramming models are decomposed and reduced from the 3 levels into 2 levels according to the idea of just-in-time production. In order to overcome the premature convergence of ACA (ant colony algorithms) , the idea of mute operation is adopted in genetic algorithms and a PACA (parallel ant colony algorithms) is proposed forsupply chain optimization. Finally, an illustrative example is given, and a comparison is made with standard BAR ( Branch and Bound) and PACA approach. The result shows that the latter is more effective and promis-ing.

  11. A new approach for solving capacitated lot sizing and scheduling problem with sequence and period-dependent setup costs

    Directory of Open Access Journals (Sweden)

    Imen Chaieb Memmi

    2013-09-01

    Full Text Available Purpose: We aim to examine the capacitated multi-item lot sizing problem which is a typical example of a large bucket model, where many different items can be produced on the same machine in one time period. We propose a new approach to determine the production sequence and lot sizes that minimize the sum of start up and setup costs, inventory and production costs over all periods.Design/methodology/approach: The approach is composed of three steps. First, we compute a lower bound on total cost. Then we propose a three sub-steps iteration procedure. We solve optimally the lot sizing problem without considering products sequencing and their cost. Then, we determine products quantities to produce each period while minimizing the storage and variable production costs. Given the products to manufacture each period, we determine its correspondent optimal products sequencing, by using a Branch and Bound algorithm. Given the sequences of products within each period, we evaluate the total start up and setup cost. We compare then the total cost obtained to the lower bound of the total cost. If this value riches a prefixed value, we stop. Otherwise, we modify the results of lot sizing problem.Findings and Originality/value: We show using an illustrative example, that the difference between the total cost and its lower bound is only 10%. This gap depends on the significance of the inventory and production costs and the machine’s capacity. Comparing the approach we develop with a traditional one, we show that we manage to reduce the total cost by 30%.Research limitations/implications: Our model fits better to real-world situations where production systems run continuously. This model is applied for limited number of part types and periods.Practical implications: Our approach determines the products to manufacture each time period, their economic amounts, and their scheduling within each period. This outcome should help decision makers bearing expensive

  12. Supplier selection and order lot sizing using dynamic programming

    Directory of Open Access Journals (Sweden)

    M. M. Moqri

    2011-04-01

    Full Text Available In this paper, we consider a multi-period integrated supplier selection and order lot sizing problem where a single buyer plans to purchase a single product in multiple periods from several qualified suppliers who are able to provide the required product with the needed quality in a timely manner. Product price and order cost differs among different suppliers. Buyer’s demand for the product is deterministic and varies for different time periods. The problem is to determine how much product from which supplier must be ordered in each period such that buyer’s demand is satisfied without violating some side constraints. We have developed a mathematical programming model to deal with this problem, and proposed a forward dynamic programming approach to obtain optimal solutions in reasonable amount of time even for large scale problems. Finally, a numerical example is conducted in which solutions obtained from the proposed dynamic programming algorithm is compared with solutions from the branch-and-bound algorithm. Through the numerical example we have shown the efficiency of our algorithm.

  13. AN OPTIMIZATION-BASED HEURISTIC FOR A CAPACITATED LOT-SIZING MODEL IN AN AUTOMATED TELLER MACHINES NETWORK

    Directory of Open Access Journals (Sweden)

    Supatchaya Chotayakul

    2013-01-01

    Full Text Available This research studies a cash inventory problem in an ATM Network to satisfy customer’s cash needs over multiple periods with deterministic demand. The objective is to determine the amount of money to place in Automated Teller Machines (ATMs and cash centers for each period over a given time horizon. The algorithms are designed as a multi-echelon inventory problem with single-item capacitated lot-sizing to minimize total costs of running ATM network. In this study, we formulate the problem as a Mixed Integer Program (MIP and develop an approach based on reformulating the model as a shortest path formulation for finding a near-optimal solution of the problem. This reformulation is the same as the traditional model, except the capacity constraints, inventory balance constraints and setup constraints related to the management of the money in ATMs are relaxed. This new formulation gives more variables and constraints, but has a much tighter linear relaxation than the original and is faster to solve for short term planning. Computational results show its effectiveness, especially for large sized problems.

  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. Dynamic programming algorithm for economic lot-sizing problem with bounded inventory and out-sourcing

    Institute of Scientific and Technical Information of China (English)

    LIU Xiao; WANG Cheng-en

    2005-01-01

    This paper addresses a single item dynamic lot-sizing model with inventory capacity and out-sourcing. The goal is to minimize the total costs of production, setup, inventory holding and out-sourcing. Two versions of an out-sourcing model with time-varying costs are considered: stock out case and conservation case. Zero Inventory Order property has been found and some new properties are obtained in an optimal solution. Dynamic programming algorithms are developed to solve the problem in strongly polynomial time respectively. Furthermore, some numerical results demonstrate that the approach proposed is efficient and applicable.

  16. Molecular dynamics simulation study on capacitive nano-accelerometers based on telescoping carbon nanotubes

    International Nuclear Information System (INIS)

    We investigated the characteristics of a capacitive nano-accelerometer based on a telescoping carbon nanotube by means of classical molecular dynamics simulations. The position of the telescoping nanotube was controlled by an externally applied force, and feedback sensing was based on the capacitance change. The capacitance variations, which were almost linearly proportional to the applied acceleration, were monitored within an error tolerance

  17. Detonation shock dynamics calibration for pBX 9502 with temperature, density, and material lot variations

    Energy Technology Data Exchange (ETDEWEB)

    Hill, Larry G [Los Alamos National Laboratory; Aslam, Tariq D [Los Alamos National Laboratory

    2010-01-01

    We present a methodology for scaling the detonation shock dynamics D{sub n}[{kappa}] calibration function to accommodate variations in the HE starting material. We apply our model to the insensitive TATB-based explosive PBX 9502, for which we have enough front curvature rate stick data to characterize three material attributes: initial temperature T{sub 0}, nominal density {rho}{sub 0}, and manufacturing lot (representing different microstructures). A useful feature of the model is that it returns an absolute estimate for the reaction zone thickness, {delta}. Lacking demonstrated material metrics(s), we express microstructural variation indirectly, in terms of its effect on {delta}. This results in a D{sub n}[{kappa}] function that depends on T{sub 0}, {rho}{sub 0}, and {delta}. After examining the separate effects of each parameter on D{sub n}[{kappa}], we compute an arc geometry as a validation problem. We compare the calculation to a PBX 9502 arc experiment that was pressed from one of the calibrated HE lots. The agreement between the model and experiment is excellent. We compute worst, nominal, and best-performing material parameter combinations to show how much difference accrues throughout the arc.

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

    OpenAIRE

    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 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 spec...

  19. Enhancement of Power System Dynamics Using TCSC Based Hybride Series Capacitive Compensation

    OpenAIRE

    Madupu Renuka*; Nomula Ganesh

    2014-01-01

    This paper demonstrate phase imbalanced series capacitive compensation to enhancing power system dynamics as it has the potential of damping power swing as well as subsynchronous resonance oscillations. In this paper, the effectiveness of a “hybrid” series capacitive compensation scheme in single line and double line to damping power system oscillations is computed. A hybrid concept is a series capacitive compensation scheme, in one case two phases are compensated by fixed ser...

  20. 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

  1. 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...

  2. Note---A Note on the Dynamic Lot-Size Model with Uncertainty in Demand and Supply Processes

    OpenAIRE

    Anderson, E. J.

    1989-01-01

    In this paper we give some extensions of a result of Nevison and Burstein (Nevison, C. H., M. Burstein. 1984. The dynamic lot-size model with stochastic lead times. Management Sci. 30 100--109.), who discuss a dynamic lot-sizing model with stochastic lead times. They consider a situation in which the lead time distribution is unaltered by the amount which is ordered, but is otherwise arbitrary, and characterize the optimal solution in terms of points at which there is zero inventory. Here we ...

  3. 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...... method leads to higher values 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...

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

    Science.gov (United States)

    Biesheuvel, P M; Bazant, M Z

    2010-03-01

    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 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) valid in the limit of thin double layers (compared to typical pore dimensions). We illustrate the theory for 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 with different time scales: (i) in the "supercapacitor regime" of small voltages and/or early times, the porous electrode acts like a transmission line, governed by a linear diffusion equation for the electrostatic potential, scaled to the RC time of a single pore, and (ii) in the "desalination regime" of large voltages and long times, the porous electrode slowly absorbs counterions, governed by coupled, nonlinear diffusion equations for the pore-averaged potential and salt concentration. PMID:20365735

  5. An efficient computational method for a stochastic dynamic lot-sizing problem under service-level constraints

    OpenAIRE

    Tarim, S. Armagan; Dogru, Mustafa K.; Oezen, Ulas; Rossi, Roberto

    2011-01-01

    We provide an efficient computational approach to solve the mixed integer programming (MIP) model developed by Tarim and Kingsman [8] for solving a stochastic lot-sizing problem with service level constraints under the static-dynamic uncertainty strategy. The effectiveness of the proposed method hinges on three novelties: (i) the proposed relaxation is computationally efficient and provides an optimal solution most of the time, (ii) if the relaxation produces an infeasible solution, then this...

  6. Coordinated Lot-sizing and Dynamic Pricing under a Supplier All-units Quantity Discount

    OpenAIRE

    Transchel, Sandra; Minner, Stefan

    2008-01-01

    We consider an economic order quantity model where the supplier offers an all-units quantity discount and a price sensitive customer demand. We compare a decentralized decision framework where selling price and replenishment policy are determined independently to simultaneous decision making. Constant and dynamic pricing are distinguished. We derive structural properties and develop algorithms that determine the optimal pricing and replenishment policy and show how quantity discounts not only...

  7. Coordinated Lot-sizing and Dynamic Prizing under a Supplier All-units Quantity Discount

    Directory of Open Access Journals (Sweden)

    Sandra Transchel

    2008-05-01

    Full Text Available We consider an economic order quantity model where the supplier offers an all-units quantity discount and a price sensitive customer demand. We compare a decentralized decision framework where selling price and replenishment policy are determined independently to simultaneous decision making. Constant and dynamic pricing are distinguished. We derive structural properties and develop algorithms that determine the optimal pricing and replenishment policy and show how quantity discounts not only influence the purchasing strategy but also the pricing policy. A sensitivity analysis indicates the impact of the fixed-holding cost ratio, the discount policy, and the customers' price sensitivity on the optimal decisions.

  8. Excitation dynamics in electrically asymmetric capacitively coupled radio frequency discharges: experiment, simulation, and model

    International Nuclear Information System (INIS)

    The symmetry of capacitively coupled radio frequency (CCRF) discharges can be controlled electrically by applying a fundamental frequency and its second harmonic with fixed but adjustable phase shift θ between the driving voltages to one electrode. In such a discharge a variable dc self-bias η is generated as an almost linear function of θ for 00 ≤ θ ≤ 900 via the Electrical Asymmetry Effect. The control parameter for η and the discharge symmetry is θ. Here electron dynamics in electrically asymmetric geometrically symmetric dual frequency discharges operated in argon at 13.56 and 27.12 MHz is investigated experimentally by a particle-in-cell simulation and by an analytical model. The electron dynamics is probed by the electron impact excitation rate of energetic electrons from the ground state into highly excited levels. At high pressures (collisional sheaths) the excitation dynamics is found to work differently compared with conventional CCRF discharges. Unlike in classical discharges the maxima of the time modulated excitation at the powered and grounded electrode within one low frequency period will be similar (symmetric excitation), if η is strong at θ ∼ 00, 900, and significantly different (asymmetric excitation), if η ∼ 0 V at θ ∼ 450. At low pressures (collisionless sheaths) the excitation dynamics works similar to classical discharges, i.e. the excitation will be asymmetric, if η is strong, and symmetric, if η ∼ 0 V. This dynamics is understood in the frame of an analytical model, which provides a more detailed insight into electron heating in CCRF discharges and could be applied to other types of capacitive RF discharges as well.

  9. Dynamic regulation of mechanosensitive channels: capacitance used to monitor patch tension in real time

    Science.gov (United States)

    Suchyna, Thomas M.; Besch, Steven R.; Sachs, Frederick

    2004-03-01

    All cells, from bacteria to human, are mechanically sensitive. The most rapid of these membrane protein transducers are mechanosensitive ion channels, ionic pores in the membrane that open and close in response to membrane tension. In specific sensory organs, these channels serve the senses of touch and hearing, and inform the central nervous system about the filling of hollow organs such as the bladder. Non-specialized cells use these channels to report on changes in cell volume and local strain. To preserve dynamic sensitivity, sensory receptors adapt to steady-state stimuli. Here we show that in rat astrocytes, the most abundant cells in the brain, this apparent adaptation to the stimulus is actually an inactivation. We have been able to track the time course of local strain by measuring attofarad changes in membrane capacitance and show that it is not correlated with loss of channel activity. The reduction in current with time is caused by an increased occupancy of low conductance states, and a reduction in the probability of opening, not a relaxation of local stress. The occupancy of these substates depends on the integrity of the cell's cytoplasm. However, while disruption of the cytoskeleton leads to a loss of inactivation, it leaves activation unaffected. The activation process is voltage-insensitive, closely correlated with changes in capacitance, and seems to arise solely from stress in the bilayer. The inactivation rate decreases with depolarization, and kinetic analysis suggests that the process involves multiple cytoplasmic ligands. Surprisingly, multivalent ions such as Gd+3 and Ca+2 that bind to the lipids and affect channel gating, do not affect the strain-induced increase in membrane capacitance; contrary to expectations, membrane elasticity is unchanged.

  10. Experimental and theoretical study of dynamic effects in low-frequency capacitively coupled discharges

    International Nuclear Information System (INIS)

    A low-frequency capacitively coupled radio-frequency (rf) discharge in Ar excited at 1.76 MHz is studied both experimentally and theoretically. Experimental measurements of electron concentration, discharge voltage and current are presented for a wide range of rf input powers. The rf current shape is nonsinusoidal, close to the triangle one. The evolution of Ar(2p1) emission excitation function in the interelectrode gap during an rf cycle is measured using the phase-resolved optical emission spectroscopy technique. Theoretical study is based on the particle-in-cell Monte Carlo collision numerical simulation. Specific dynamic features of the low-frequency discharge are discussed. The important role of secondary electrons in discharge maintenance and power balance is shown. This study is crucial for understanding dual-frequency discharges with a corresponding value of low frequency. (paper)

  11. Characterising thermal resistances and capacitances of GaN high-electron-mobility transistors through dynamic electrothermal measurements

    DEFF Research Database (Denmark)

    Wei, Wei; Mikkelsen, Jan H.; Jensen, Ole Kiel

    2014-01-01

    This study presents a method to characterise thermal resistances and capacitances of GaN high-electron-mobility transistors (HEMTs) through dynamic electrothermal measurements. A measured relation between RF gain and the channel temperature (Tc) is formed and used for indirect measurements of...

  12. Dynamic Visualization Approach of the Multiphase Flow Using Electrical Capacitance Tomography

    Institute of Scientific and Technical Information of China (English)

    王泽璞; 陈琪; 王雪瑶; 李志宏; 韩振兴

    2012-01-01

    Identifying the flow patterns is vital for understanding the complicated physical mechanisms in multiphase flows.For this purpose,electrical capacitance tomography(ECT) technique is considered as a promising visualization method for the flow pattern identification,in which image reconstruction algorithms play an important role.In this paper,a generalized dynamic reconstruction model,which integrates ECT measurement information and physical evolution information of the objects of interest,was presented.A generalized objective functional that simultaneously considers the spatial constraints,temporal constraints and dynamic evolution information of the objects of interest was proposed.Numerical simulations and experiments were implemented to evaluate the feasibility and efficiency of the proposed algorithm.For the cases considered in this paper,the proposed algorithm can well reconstruct the flow patterns,and the quality of the reconstructed images is improved,which indicates that the proposed algorithm is competent to reconstruct the flow patterns in the visualization of multiphase flows.

  13. Identification of Capacitive MEMS Accelerometer Structure Parameters for Human Body Dynamics Measurements

    Directory of Open Access Journals (Sweden)

    Vincas Benevicius

    2013-08-01

    Full Text Available Due to their small size, low weight, low cost and low energy consumption, MEMS accelerometers have achieved great commercial success in recent decades. The aim of this research work is to identify a MEMS accelerometer structure for human body dynamics measurements. Photogrammetry was used in order to measure possible maximum accelerations of human body parts and the bandwidth of the digital acceleration signal. As the primary structure the capacitive accelerometer configuration is chosen in such a way that sensing part measures on all three axes as it is 3D accelerometer and sensitivity on each axis is equal. Hill climbing optimization was used to find the structure parameters. Proof-mass displacements were simulated for all the acceleration range that was given by the optimization problem constraints. The final model was constructed in Comsol Multiphysics. Eigenfrequencies were calculated and model’s response was found, when vibration stand displacement data was fed into the model as the base excitation law. Model output comparison with experimental data was conducted for all excitation frequencies used during the experiments.

  14. Capacitively coupled hydrogen plasmas sustained by tailored voltage waveforms: excitation dynamics and ion flux asymmetry

    Science.gov (United States)

    Bruneau, B.; Diomede, P.; Economou, D. J.; Longo, S.; Gans, T.; O’Connell, D.; Greb, A.; Johnson, E.; Booth, J.-P.

    2016-08-01

    Parallel plate capacitively coupled plasmas in hydrogen at relatively high pressure (~1 Torr) are excited with tailored voltage waveforms containing up to five frequencies. Predictions of a hybrid model combining a particle-in-cell simulation with Monte Carlo collisions and a fluid model are compared to phase resolved optical emission spectroscopy measurements, yielding information on the dynamics of the excitation rate in these discharges. When the discharge is excited with amplitude asymmetric waveforms, the discharge becomes electrically asymmetric, with different ion energies at each of the two electrodes. Unexpectedly, large differences in the \\text{H}2+ fluxes to each of the two electrodes are caused by the different \\text{H}3+ energies. When the discharge is excited with slope asymmetric waveforms, only weak electrical asymmetry of the discharge is observed. In this case, electron power absorption due to fast sheath expansion at one electrode is balanced by electron power absorption at the opposite electrode due to a strong electric field reversal.

  15. MODEL PENENTUAN UKURAN LOT PRODUKSI DENGAN POLA PERMINTAAN BERFLUKTUASI

    Directory of Open Access Journals (Sweden)

    Docki Saraswati

    2009-01-01

    Full Text Available The purpose of this paper is to examine the impact of varying demand on the production lot size and the schedule of delivery in the integrated inventory system. This system is consisted of a single manufacturer as the supplier and a single buyer. Mostly, the problems on the economic lot size model are assumed that demand is continuous with time. Actually, demand occurs are varying in time rather than continuously over the planning time horizon. In this case, the buyer has decided the amount of order for each period is varied, because of the changing market environment. The integrated inventory system model between a supplier and a buyer are developed and implemented under the condition with varied demand. Forward dynamic programming is implemented for searching the solution. The objective is to minimize the total cost, associated with a single product for a deterministic varying demand. Two conditions are examined here, i.e., the integrated model with uncapacitated and capacitated production system. The difference between these two models is in the constraints formulation. The capacity constraints will give higher total cost, especially if the setup cost higher than the holding cost. A numerical example is presented to illustrate the implementation of the solution algorithm. Abstract in Bahasa Indonesia: Pada makalah ini diteliti pengaruh permintaan yang berfluktuasi terhadap penentuan ukuran lot produksi dan jadwal pengiriman pada sistem persediaan terintegrasi, dengan total ongkos persediaan melibatkan sistem persediaan pemanufaktur dan pembeli secara bersama. Sistem terdiri atas pemanufaktur tunggal dan pembeli tunggal untuk pemesanan satu jenis produk.Umumnya permasalahan penentuan ukuran lot produksi memiliki asumsi bahwa permintaan bersifat kontinu terhadap waktu. Penentuan ukuran lot pada model integrasi sistem persediaan antara pemanufaktur dan pembeli dengan kondisi permintaan berfluktuatif bertujuan meminimasi total ongkos. Pencarian

  16. Dynamic Characteristics of X-pinch Experiments Conducted in a Small Capacitive Generator:Refractive Optical Observations.

    Science.gov (United States)

    Sepúlveda, Adolfo; Pavez, Cristian; Pedreros, José; Avaria, Gonzalo; San Martín, Patricio; Soto, Leopoldo

    2016-05-01

    Among the dense plasmas configurations of interest for applications as a portable intense source of X-rays, the X-pinches are the most attractive by their brightness, source size, short duration and space localization, being particularly reproducible when they are conducted with fast pulsed power generators. In recent time, several characteristics of the dynamics and emission have been reproduced in compact generators (typically capacitive generators) of low current rise-rate (less than 0.5 kA/ns). In this work, a preliminary characterization of the dynamic of X-pinch plasma conducted in a small capacitive generator is reported. In order to obtain the plasma dynamics and quantitative information of the plasma density, the dark field Schlieren technique and interferometry were implemented. The experiments were carried out on the multipurpose generator (1.2 μF, 345 J, 47.5 nH, T/4=375 ns and Z = 0.2 Ω in short circuit) capable to produce currents up to 122 kA with 500 ns quarter period, when a charging voltage of 24 kV and metallic X-pinches are used as load. The electrical behavior of the discharge and the X-ray emission are monitored with a Rogowski coil and filtered PIN diodes respectively. For the refractive optical diagnostics a 532 nm frequency- doubled Nd-YAG laser was used. As from a single Schlieren record per shot, a sequence with the time evolution of the plasma is constructed. From the images, a similar dynamic of X- pinches conducted in fast generators of high current is observed, where structures such as coronal plasma, plasma flares and plasma jets are identified. The plasma dynamics observed from a VUV gated pinhole image system is compared with registered dynamic with refractive optical techniques.

  17. 116 dB dynamic range CMOS readout circuit for MEMS capacitive accelerometer

    International Nuclear Information System (INIS)

    A high stability in-circuit reprogrammable technique control system for a capacitive MEMS accelerometer is presented. Modulation and demodulation are used to separate the signal from the low frequency noise. A low-noise low-offset charge integrator is employed in this circuit to implement a capacitance-to-voltage converter and minimize the noise and offset. The application-specific integrated circuit (ASIC) is fabricated in a 0.5 μm one-ploy three-metal CMOS process. The measured results of the proposed circuit show that the noise floor of the ASIC is −116 dBV, the sensitivity of the accelerometer is 66 mV/g with a nonlinearity of 0.5%. The chip occupies 3.5 × 2.5 mm2 and the current is 3.5 mA. (semiconductor integrated circuits)

  18. A 97 dB dynamic range CSA-based readout circuit with analog temperature compensation for MEMS capacitive sensors

    International Nuclear Information System (INIS)

    This paper presents a charge-sensitive-amplifier (CSA) based readout circuit for capacitive microelectro-mechanical-system (MEMS) sensors. A continuous-time (CT) readout structure using the chopper technique is adopted to cancel the low frequency noise and improve the resolution of the readout circuits. An operational trans-conductance amplifier (OTA) structure with an auxiliary common-mode-feedback-OTA is proposed in the fully differential CSA to suppress the chopper modulation induced disturbance at the OTA input terminal. An analog temperature compensation method is proposed, which adjusts the chopper signal amplitude with temperature variation to compensate the temperature drift of the CSA readout sensitivity. The chip is designed and implemented in a 0.35 μm CMOS process and is 2.1 × 2.1 mm2 in area. The measurement shows that the readout circuit achieves 0.9 aF / √Hz capacitive resolution, 97 dB dynamic range in 100 Hz signal bandwidth, and 0.8 mV/fF sensitivity with a temperature drift of 35 ppm/°C after optimized compensation. (semiconductor integrated circuits)

  19. Phase resolved optical emission spectroscopy: a non-intrusive diagnostic to study electron dynamics in capacitive radio frequency discharges

    International Nuclear Information System (INIS)

    Various types of capacitively coupled radio frequency (CCRF) discharges are frequently used for different applications ranging from chip and solar cell manufacturing to the creation of biocompatible surfaces. In many of these discharges electron heating and electron dynamics are not fully understood. A powerful diagnostic to study electron dynamics in CCRF discharges is phase resolved optical emission spectroscopy (PROES). It is non-intrusive and provides access to the dynamics of highly energetic electrons, which sustain the discharge via ionization, with high spatial and temporal resolution within the RF period. Based on a time dependent model of the excitation dynamics of specifically chosen rare gas levels PROES provides access to plasma parameters such as the electron temperature, electron density and electron energy distribution function (EEDF). In this work the method of PROES is reviewed and some examples of its application are discussed. First, the generation of highly energetic electron beams by the expanding sheath in geometrically symmetric as well as asymmetric discharges and their effect on the EEDF are investigated. Second, the physical nature of the frequency coupling in dual frequency discharges operated at substantially different frequencies is discussed. Third, the generation of electric field reversals during sheath collapse in single and dual frequency discharges is analysed. Then excitation dynamics in an electrically asymmetric novel type of dual frequency discharge is studied. Finally, limitations of PROES are discussed.

  20. Simulation of Main Plasma Parameters of a Cylindrical Asymmetric Capacitively Coupled Plasma Micro-Thruster using Computational Fluid Dynamics

    Directory of Open Access Journals (Sweden)

    Amelia eGreig

    2015-01-01

    Full Text Available Computational fluid dynamics (CFD simulations of a radio-frequency (13.56 MHz electro-thermal capacitively coupled plasma (CCP micro-thruster have been performed using the commercial CFD-ACE+ package. Standard operating conditions of a 10 W, 1.5 Torr argon discharge were used to compare with previously obtained experimental results for validation. Results show that the driving force behind plasma production within the thruster is ion-induced secondary electrons ejected from the surface of the discharge tube, accelerated through the sheath to electron temperatures up to 33.5 eV. The secondary electron coefficient was varied to determine the effect on the discharge, with results showing that full breakdown of the discharge did not occur for coefficients coefficients less than or equal to 0.01.

  1. A 100 μm diameter capacitive pressure sensor with 50 MPa dynamic range

    Science.gov (United States)

    Luo, Xin; Gianchandani, Yogesh B.

    2016-04-01

    This paper presents fully sealed absolute capacitive pressure sensors for high-pressure applications in hydraulic environments. The sensors have a ø100 μm diaphragm and a nominal interelectrode gap of 3 μm. The interiors of the cavities are electrically isolated, allowing the sensors to operate at the high end of the pressure range with the center of the diaphragm in contact with the substrate beneath it. The sensors are monolithically fabricated using a combination of surface micromachining and through-wafer isolated bulk-silicon lead transfer for backside contacts. This structure allows the device footprints to be reduced to about 150  ×  150 μm2, and simplifies system integration. Fabricated sensors with diaphragm thicknesses of 3 μm (C100t3) and 5 μm (C100t5) are tested in an oil environment at pressures up to 20 MPa and 50 MPa, respectively. The average sensitivities are 7200 ppm MPa-1 (3.1 fF MPa-1) for C100t3, and 3400 ppm MPa-1 (1.6 fF MPa-1) for C100t5 in the non-contact mode. In the contact mode, the average sensitivities are 9900 ppm MPa-1 (5.3 fF MPa-1) for C100t3, and 3100 ppm MPa-1 (1.6 fF MPa-1) for C100t5. A multiphysics finite element analysis approach that accommodates contact mode simulations is also presented.

  2. Experimental investigations of electron heating dynamics and ion energy distributions in capacitive discharges driven by customized voltage waveforms

    International Nuclear Information System (INIS)

    Capacitively coupled radio frequency plasmas driven by customized voltage waveforms provide enhanced opportunities to control process-relevant energy distributions of different particle species. Here, we present an experimental investigation of the spatio-temporal electron heating dynamics probed by Phase-Resolved Optical Emission Spectroscopy (PROES) in an argon discharge driven by up to three consecutive harmonics of 13.56 MHz with individually adjustable harmonics' amplitudes and phases. PROES and voltage measurements are performed at fixed total voltage amplitudes as a function of the number of driving harmonics, their relative phases, and pressure to study the effects of changing the applied voltage waveform on the heating dynamics in collisionless and collisional regimes. Additionally, the ion energy distribution function (IEDF) is measured at low pressure. In this collisionless regime, the discharge is operated in the α-mode. The velocity of energetic electron beams generated by the expanding sheaths is found to be affected by the number of driving harmonics and their relative phases. This is understood based on the sheath dynamics obtained from a model that determines sheath voltage waveforms. The formation of the measured IEDFs is understood and found to be directly affected by the observed changes in the electron heating dynamics. It is demonstrated that the mean ion energy can be controlled by adjusting the harmonics' phases. In the collisional regime at higher pressures changing the number of harmonics and their phases at fixed voltage is found to induce heating mode transitions from the α- to the γ-mode. Finally, a method to use PROES as a non-invasive diagnostic to monitor and detect changes of the ion flux to the electrodes is developed

  3. Experimental investigations of electron heating dynamics and ion energy distributions in capacitive discharges driven by customized voltage waveforms

    Energy Technology Data Exchange (ETDEWEB)

    Berger, Birk [Department of Physics, West Virginia University, Morgantown, West Virginia 26506-6315 (United States); Institute for Theoretical Electrical Engineering, Ruhr University Bochum, D-44780 Bochum (Germany); Brandt, Steven; Franek, James; Schüngel, Edmund; Koepke, Mark; Schulze, Julian [Department of Physics, West Virginia University, Morgantown, West Virginia 26506-6315 (United States); Mussenbrock, Thomas [Institute for Theoretical Electrical Engineering, Ruhr University Bochum, D-44780 Bochum (Germany)

    2015-12-14

    Capacitively coupled radio frequency plasmas driven by customized voltage waveforms provide enhanced opportunities to control process-relevant energy distributions of different particle species. Here, we present an experimental investigation of the spatio-temporal electron heating dynamics probed by Phase-Resolved Optical Emission Spectroscopy (PROES) in an argon discharge driven by up to three consecutive harmonics of 13.56 MHz with individually adjustable harmonics' amplitudes and phases. PROES and voltage measurements are performed at fixed total voltage amplitudes as a function of the number of driving harmonics, their relative phases, and pressure to study the effects of changing the applied voltage waveform on the heating dynamics in collisionless and collisional regimes. Additionally, the ion energy distribution function (IEDF) is measured at low pressure. In this collisionless regime, the discharge is operated in the α-mode. The velocity of energetic electron beams generated by the expanding sheaths is found to be affected by the number of driving harmonics and their relative phases. This is understood based on the sheath dynamics obtained from a model that determines sheath voltage waveforms. The formation of the measured IEDFs is understood and found to be directly affected by the observed changes in the electron heating dynamics. It is demonstrated that the mean ion energy can be controlled by adjusting the harmonics' phases. In the collisional regime at higher pressures changing the number of harmonics and their phases at fixed voltage is found to induce heating mode transitions from the α- to the γ-mode. Finally, a method to use PROES as a non-invasive diagnostic to monitor and detect changes of the ion flux to the electrodes is developed.

  4. Electron power absorption dynamics in capacitive radio frequency discharges driven by tailored voltage waveforms in CF4

    Science.gov (United States)

    Brandt, S.; Berger, B.; Schüngel, E.; Korolov, I.; Derzsi, A.; Bruneau, B.; Johnson, E.; Lafleur, T.; O’Connell, D.; Koepke, M.; Gans, T.; Booth, J.-P.; Donkó, Z.; Schulze, J.

    2016-08-01

    The power absorption dynamics of electrons and the electrical asymmetry effect in capacitive radio-frequency plasmas operated in CF4 and driven by tailored voltage waveforms are investigated experimentally in combination with kinetic simulations. The driving voltage waveforms are generated as a superposition of multiple consecutive harmonics of the fundamental frequency of 13.56 MHz. Peaks/valleys and sawtooth waveforms are used to study the effects of amplitude and slope asymmetries of the driving voltage waveform on the electron dynamics and the generation of a DC self-bias in an electronegative plasma at different pressures. Compared to electropositive discharges, we observe strongly different effects and unique power absorption dynamics. At high pressures and high electronegativities, the discharge is found to operate in the drift-ambipolar (DA) heating mode. A dominant excitation/ionization maximum is observed during sheath collapse at the edge of the sheath which collapses fastest. High negative-ion densities are observed inside this sheath region, while electrons are confined for part of the RF period in a potential well formed by the ambipolar electric field at this sheath edge and the collapsed (floating potential) sheath at the electrode. For specific driving voltage waveforms, the plasma becomes divided spatially into two different halves of strongly different electronegativity. This asymmetry can be reversed electrically by inverting the driving waveform. For sawtooth waveforms, the discharge asymmetry and the sign of the DC self-bias are found to reverse as the pressure is increased, due to a transition of the electron heating mode from the α-mode to the DA-mode. These effects are interpreted with the aid of the simulation results.

  5. Capacitive Proximity Sensor Has Longer Range

    Science.gov (United States)

    Vranish, John M.

    1992-01-01

    Capacitive proximity sensor on robot arm detects nearby object via capacitive effect of object on frequency of oscillator. Sensing element part of oscillator circuit operating at about 20 kHz. Total capacitance between sensing element and ground constitutes tuning capacitance of oscillator. Sensor circuit includes shield driven by replica of alternating voltage applied to sensing element. Driven shield concentrates sensing electrostatic field in exterior region to enhance sensitivity to object. Sensitivity and dynamic range has corresponding 12-to-1 improvement.

  6. Dynamics of electronic transitions and frequency dependence of negative capacitance in semiconductor diodes under high forward bias

    International Nuclear Information System (INIS)

    We observed qualitatively dissimilar frequency dependence of negative capacitance under high charge injection in two sets of functionally different junction diodes: III-V based light emitting and Si-based non-light emitting diodes. Using an advanced approach based on bias activated differential capacitance, we developed a generalized understanding of negative capacitance phenomenon which can be extended to any diode based device structure. We explained the observations as the mutual competition of fast and slow electronic transition rates which are different in different devices. This study can be useful in understanding the interfacial effects in semiconductor heterostructures and may lead to superior device functionality.

  7. Capacitive Extensometer

    Science.gov (United States)

    Perusek, Gail P. (Inventor)

    2003-01-01

    The present invention provides for measurements of the principal strain magnitudes and directions, and maximum shear strain that occurs in a porous specimen, such as plastic, ceramic or porous metal, when it is loaded (or subjected to a load). In one embodiment the invention includes a capacitive delta extensometer arranged with six sensors in a three piece configuration, with each sensor of each pair spaced apart from each other by a predetermined angle, such as 120 degrees.

  8. Rapid small lot manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Harrigan, R.W.

    1998-05-09

    The direct connection of information, captured in forms such as CAD databases, to the factory floor is enabling a revolution in manufacturing. Rapid response to very dynamic market conditions is becoming the norm rather than the exception. In order to provide economical rapid fabrication of small numbers of variable products, one must design with manufacturing constraints in mind. In addition, flexible manufacturing systems must be programmed automatically to reduce the time for product change over in the factory and eliminate human errors. Sensor based machine control is needed to adapt idealized, model based machine programs to uncontrolled variables such as the condition of raw materials and fabrication tolerances.

  9. On-line method to study dynamics of ion adsorption from mixtures of salts in capacitive deionization

    NARCIS (Netherlands)

    Dykstra, J.E.; Dijkstra, J.; Wal, van der A.; Hamelers, H.V.M.; Porada, S.

    2016-01-01

    Capacitive Deionization (CDI) is a water desalination technology that adsorbs ions into two oppositely polarized porous carbon electrodes, under the action of an applied voltage. Here, we introduce a novel method to analyze the effluent concentration of multiple ionic species in mixtures of salt

  10. Nanoscale capacitance: A classical charge-dipole approximation

    OpenAIRE

    Jun-Qiang Lu; Jonathan Gonzalez; Carlos Sierra; Yang Li

    2013-01-01

    Modeling nanoscale capacitance presents particular challenge because of dynamic contribution from electrodes, which can usually be neglected in modeling macroscopic capacitance and nanoscale conductance. We present a model to calculate capacitances of nano-gap configurations and define effective capacitances of nanoscale structures. The model is implemented by using a classical atomic charge-dipole approximation and applied to calculate capacitance of a carbon nanotube nano-gap and effective ...

  11. False capacitance of supercapacitors

    OpenAIRE

    Ragoisha, G. A.; Aniskevich, Y. M.

    2016-01-01

    Capacitance measurements from cyclic voltammetry, galvanostatic chronopotentiometry and calculation of capacitance from imaginary part of impedance are widely used in investigations of supercapacitors. The methods assume the supercapacitor is a capacitor, while real objects correspond to different equivalent electric circuits and show various contributions of non-capacitive currents to the current which is used for calculation of capacitance. Specific capacitances which are presented in F g-1...

  12. Membrane capacitance techniques to monitor granule exocytosis in neutrophils.

    OpenAIRE

    Lollike, K; Lindau, M

    1999-01-01

    Cell membranes behave like electrical capacitors and changes in cell capacitance therefore reflect changes in the cell area. Monitoring capacitance can thus be used to study dynamic cellular phenomenon involving rapid changes in cell surface, such as exo- and/or endocytosis. In this review focus is on the use of capacitance techniques to study exocytosis in human neutrophils. We compare the whole-cell and the cell-attached capacitance techniques, and we review the complete literature dealing ...

  13. Record Dynamics in the Parking Lot Model

    DEFF Research Database (Denmark)

    Sibani, Paolo; Boettcher, Stefan

    2016-01-01

    which must be re-arranged to reach new records in density, we find that their length-scale grows logarithmically with time for low enough temperatures. We further characterize the aging process in terms of the statistics of fluctuations in the interstitial free volume that shows a clear separation...

  14. Effect of a pre-freezing treatment with cholesterol-loaded cyclodextrins on boar sperm longevity, capacitation dynamics, ability to adhere to porcine oviductal epithelial cells in vitro and DNA fragmentation dynamics.

    Science.gov (United States)

    Tomás, C; Blanch, E; Fazeli, A; Mocé, E

    2013-01-01

    The aim of this work was to examine how a pre-freezing treatment with cholesterol-loaded cyclodextrins (CLC) affects boar sperm longevity, capacitation dynamics, ability to bind to a porcine telomerase-immortalised oviductal epithelial cell line (TERT-OPEC) in vitro and DNA integrity dynamics after freeze-thawing. Although the samples treated with CLC exhibited lower sperm quality than the control samples (P0.05) after long-term incubation (26h at 37 or 16°C). Additionally, the CLC-treated spermatozoa underwent similar capacitation and DNA fragmentation dynamics as the control spermatozoa (P>0.05). However, CLC-treated spermatozoa were better able to bind to TERT-OPEC in vitro (POPEC in vitro, which could have an effect on the establishment of the sperm reservoir in the ampullary--isthmic junction in vivo. Additionally, frozen-thawed spermatozoa can be stored at 16°C for at least 6h without a significant observable decline in sperm quality, which could be beneficial for the transport of thawed diluted doses of spermatozoa from the laboratory to the farm. PMID:23036662

  15. 7 CFR 987.102 - Lot number.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Lot number. 987.102 Section 987.102 Agriculture... RIVERSIDE COUNTY, CALIFORNIA Administrative Rules Definitions § 987.102 Lot number. Lot number is synonymous with code and means a combination of letters or numbers, or both, acceptable to the Committee,...

  16. 7 CFR 29.35 - Lot seal.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Lot seal. 29.35 Section 29.35 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Regulations Definitions § 29.35 Lot seal. A seal approved by the Director for sealing lots...

  17. Improving capacitance/damping ratio in a capacitive MEMS transducer

    International Nuclear Information System (INIS)

    Damping forces play an important role in capacitive MEMS (microelectromechanical systems) behavior, and typical damper design (parallel-plates) cannot address the design conflict between increase in electrical capacitance and damping reduction. Squeeze-film damping in in-plane parallel-plate MEMS is discussed here and a novel damper geometry for gap-varying parallel-plates is introduced and used to increase the capacitance/damping ratio. The new geometry is compared with a typical parallel-plate design for an silicon-on-insulator process (25 µm thick) and experimental data shows an approximate 25% to 50% reduction for the damping coefficient in structures with 500 µm long dampers (for a gap variation between 0.75 and 3.75 µm), in agreement with computational fluid dynamics simulations, without significantly affecting the capacitance value (∼4% reduction). Preliminary simulations to study the role of the different geometric parameters involved in the improved geometry are also performed and reveal that the channel width is the most critical value for effective damping reduction. (paper)

  18. Mesoscopic Capacitance Oscillations

    OpenAIRE

    Buttiker, Markus; Nigg, Simon

    2006-01-01

    We examine oscillations as a function of Fermi energy in the capacitance of a mesoscopic cavity connected via a single quantum channel to a metallic contact and capacitively coupled to a back gate. The oscillations depend on the distribution of single levels in the cavity, the interaction strength and the transmission probability through the quantum channel. We use a Hartree-Fock approach to exclude self-interaction. The sample specific capacitance oscillations are in marked contrast to the c...

  19. Electrical capacitance tomography (ECT) and gamma radiation meter for comparison with and validation and tuning of computational fluid dynamics (CFD) modeling of multiphase flow

    International Nuclear Information System (INIS)

    The electrical capacitance tomographic (ECT) approach is increasingly seen as attractive for measurement and control applications in the process industries. Recently, there is increased interest in using the tomographic details from ECT for comparing with and validating and tuning CFD models of multiphase flow. Collaboration with researchers working in the field of computational fluid dynamics (CFD) modeling of multiphase flows gives valuable information for both groups of researchers in the field of ECT and CFD. By studying the ECT tomograms of multiphase flows under carefully monitored inflow conditions of the different media and by obtaining the capacitance values, C(i, j, t) with i = 1…N, j = 1, 2,…N and i ≠ j obtained from ECT modules with N electrodes, it is shown how the interface heights in a pipe with stratified flow of oil and air can be fruitfully compared to the values of those obtained from ECT and gamma radiation meter (GRM) for improving CFD modeling. Monitored inflow conditions in this study are flow rates of air, water and oil into a pipe which can be positioned at varying inclinations to the horizontal, thus emulating the pipelines laid in subsea installations. It is found that ECT-based tomograms show most of the features seen in the GRM-based visualizations with nearly one-to-one correspondence to interface heights obtained from these two methods, albeit some anomalies at the pipe wall. However, there are some interesting features the ECT manages to capture: features which the GRM or the CFD modeling apparently do not show, possibly due to parameters not defined in the inputs to the CFD model or much slower response of the GRM. Results presented in this paper indicate that a combination of ECT and GRM and preferably with other modalities with enhanced data fusion and analysis combined with CFD modeling can help to improve the modeling, measurement and control of multiphase flow in the oil and gas industries and in the process industries

  20. Variable Synthetic Capacitance

    Science.gov (United States)

    Kleinberg, L. L.

    1986-01-01

    Feedback amplifier circuit synthesizes electronically variable capacitance. Variable Synthetic Capacitor is amplifier circuit with follower/feedback configuration. Effective input capacitance depends on input set current. If synthetic capacitor is connected across resonant element of oscillator, oscillator frequency controlled via input set current. Circuit especially suitable for fine frequency adjustments of piezoelectric-crystal or inductor/capacitor resonant oscillators.

  1. Dynamic Lot Sizing Problem of Production and Outsourcing under the Environment of Different Customer Classes%不同顾客环境下生产及外包的动态批量问题

    Institute of Scientific and Technical Information of China (English)

    徐娟; 汪小京; 刘志学

    2014-01-01

    This paper considers a dynamic lot sizing problem of production and outsourcing with different kinds of customer class (e.g.,high valuable and low valuable one) demand in a finite time horizon.The firm can produce in house or outsourcing from outside in order to satisfy different customer demand,and then five service policies are obtained.The optimal outsourcing policy does not necessarily satisfy the Zero-Inventory-Outsourcing rule,and the optimal production policy does not necessarily satisfy the Zero-Inventory-Production rule.However,the set of production periods for high valuable customer must include the set for low valuable one.Based on this lemma,a polynomial algorithm is proposed to search out the optimal production and outsourcing policy,with time complexity O(N3),and a numeric example is given to illustrate the five service policies.At last,when the number of customer classes is larger,two heuristics are designed according to the special production and outsourcing rule.%在有限计划期内,考虑不同顾客(例如:高端和低端顾客)具有不同的缺货等待成本,企业可以采用生产或者外包的方式满足不同顾客需求.在生产和外包两种策略下,企业有五种不同的服务方式,而最优外包期不一定满足“零库存外包”规则,最优生产期不一定满足“零库存生产”规则,但满足高端顾客需求的生产期必须包含满足低端顾客需求的生产期.基于此性质,提出了一个多项式算法得到最优的生产及外包策略,并为每类顾客制定相应的服务策略,计算复杂度为O(N3),并通过算例分析了五种不同的服务策略.最后,拓展到多类顾客的需求环境,根据特殊的生产法则和顾客分类方法,分别设计了一种启发式算法,得到企业的生产及外包策略.

  2. LOT, a meso scale mechanistic tool for Porous Asphalt mixture design; winter damage and LOT validation

    NARCIS (Netherlands)

    Huurman, M.; Mo, L.T.; Woldekidan, M.F.

    2010-01-01

    By assignment of the Centre for Transport and Navigation (DVS) of the Dutch Ministry of Transport, Public Works and Water Management the Delft University of Technology developed LOT. LOT is a Lifetime Optimisation Tool for Porous Asphalt, PA, based on meso scale structural modelling. LOT sees an asp

  3. System for Measuring Capacitance

    Science.gov (United States)

    McNichol, Randal S. (Inventor)

    2001-01-01

    A system has been developed for detecting the level of a liquid in a tank wherein a capacitor positioned in the tank has spaced plates which are positioned such that the dielectric between the plates will be either air or the liquid, depending on the depth of the liquid in the tank. An oscillator supplies a sine wave current to the capacitor and a coaxial cable connects the capacitor to a measuring circuit outside the tank. If the cable is very long or the capacitance to be measured is low, the capacitance inherent in the coaxial cable will prevent an accurate reading. To avoid this problem, an inductor is connected across the cable to form with the capacitance of the cable a parallel resonant circuit. The impedance of the parallel resonant circuit is infinite, so that attenuation of the measurement signal by the stray cable capacitance is avoided.

  4. Capacitance pressure sensor

    Science.gov (United States)

    Eaton, William P.; Staple, Bevan D.; Smith, James H.

    2000-01-01

    A microelectromechanical (MEM) capacitance pressure sensor integrated with electronic circuitry on a common substrate and a method for forming such a device are disclosed. The MEM capacitance pressure sensor includes a capacitance pressure sensor formed at least partially in a cavity etched below the surface of a silicon substrate and adjacent circuitry (CMOS, BiCMOS, or bipolar circuitry) formed on the substrate. By forming the capacitance pressure sensor in the cavity, the substrate can be planarized (e.g. by chemical-mechanical polishing) so that a standard set of integrated circuit processing steps can be used to form the electronic circuitry (e.g. using an aluminum or aluminum-alloy interconnect metallization).

  5. 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.

  6. Induced Charge Capacitive Deionization

    OpenAIRE

    Rubin, S.; Suss, M. E.; 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, ...

  7. Nonlinear Quantum Capacitance

    OpenAIRE

    Wang, B; Zhao, X; Guo, H; Wang, J.

    1999-01-01

    We analyze the nonlinear voltage dependence of electrochemical capacitance for nanoscale conductors. This voltage dependence is due to the finite density of states of the conductors. Within Hartree theory we derive an exact expression for the electrochemical capacitance–voltage curve for a parallel plate system. The result suggests a quantum scanning capacitance microscopy at the nanoscale: by inverting the capacitance–voltage expression one is able to deduce the local spectral function of th...

  8. Quantum capacitance: a microscopic derivation

    OpenAIRE

    Mukherjee, Sreemoyee; MANNINEN, M; Deo, P. Singha

    2010-01-01

    We start from microscopic approach to many body physics and show the analytical steps and approximations required to arrive at the concept of quantum capacitance. These approximations are valid only in the semi-classical limit and the quantum capacitance in that case is determined by Lindhard function. The effective capacitance is the geometrical capacitance and the quantum capacitance in series, and this too is established starting from a microscopic theory.

  9. ANALYSIS OF HARRELL MONOSODIUM TITANATE LOT 46000908120

    Energy Technology Data Exchange (ETDEWEB)

    Taylor-Pashow, K.

    2014-04-09

    Monosodium titanate (MST) for use in the Actinide Removal Process (ARP) must be qualified and verified in advance. A single qualification sample for each batch of material is sent to SRNL for analysis, as well as a statistical sampling of verification samples. The original Harrell Industries Lot #46000908120 qualification and 16 verification samples received in October 2012 failed to meet the specification for weight percent solids. All of the pails sampled and tested contained less than 15 wt % MST solids. The lot was returned to the vendor, and in February 2014 a new qualification sample and set of 16 verification samples were received from this lot. The new lot met each of the selected specification requirements that were tested and, consequently, the material is acceptable for use in the ARP process.

  10. ANALYSIS OF HARRELL MONOSODIUM TITANATE LOT 46000824120

    Energy Technology Data Exchange (ETDEWEB)

    Taylor-Pashow, K.

    2014-04-09

    Monosodium titanate (MST) for use in the Actinide Removal Process (ARP) must be qualified and verified in advance. A single qualification sample for each batch of material is sent to SRNL for analysis, as well as a statistical sampling of verification samples. The original Harrell Industries Lot #46000824120 qualification and 16 verification samples received in September 2012 failed to meet the specification for weight percent solids. All of the pails sampled and tested contained less than 15 wt % MST solids. The lot was returned to the vendor, and in February 2014 a new qualification sample and set of 14 verification samples were received from this lot. The new lot met each of the selected specification requirements that were tested and, consequently, the material is acceptable for use in the ARP process.

  11. A RELATIVE BENEFIT ALGORITHM FOR BASIC ECONOMIC LOT SIZE PROBLEM

    Institute of Scientific and Technical Information of China (English)

    马辉民; 张子刚; 周少甫; 黄卫来

    2001-01-01

    The paper develops an algorithm that solves economic lot size problem in O(n2) time in the Wagner-Whitin case. The algorithm is based on the standard dynamic programming approach which requires the computation of the maximal relative benefit for some possible subplans of the production plan. In this algorithm the authors have studied the forward property and decomposition properties which can make computation easy. The proposed algorithm appears to perform quite reasonably for practical application.

  12. Analysis Of Harrell Monosodium Titanate LOT 03031

    International Nuclear Information System (INIS)

    Monosodium titanate (MST) for use in the Actinide Removal Process (ARP) must be qualified and verified in advance. A single qualification sample for each batch of material is sent to SRNL for analysis, as well as a statistical sampling of verification samples. The Harrell Industries Lot 030311 qualification and 9 verification samples met all the requirements in the specification indicating the material is acceptable for use in the process. Harrell Industries is under contract with Savannah River Remediation to provide MST for use in the Actinide Removal Process (ARP). A 500-mL qualification sample for Lot 030311 was sent to the Savannah River National Laboratory (SRNL) to confirm the material meets the requirements specified in the purchase specification. The vendor is also obligated to send verification samples from ∼10% or more of the pails of MST product for each lot (distributed roughly evenly through the entire lot of pails). For the verification of this lot, Harrell Industries sent 9 samples, one each from pails 1, 5, 15, 20, 25, 30, 40, 45, and 55 of 59 total pails.

  13. Burning Cars in a Parking Lot

    Science.gov (United States)

    Bertoin, Jean

    2011-08-01

    Knuth's parking scheme is a model in computer science for hashing with linear probing. One may imagine a circular parking lot with n sites; cars arrive at each site with unit rate. When a car arrives at a vacant site, it parks there; otherwise it turns clockwise and parks at the first vacant site which is found. We incorporate fires into this model by throwing Molotov cocktails on each site at a smaller rate n - α , where 0 2/3, whereas for α < 2/3, the average occupation approaches 1 at time 1 but then quickly drops to 0 before the parking lot is ever saturated. Our study relies on asymptotics for the occupation of the parking lot without fires in certain regimes which may be of independent interest.

  14. Capacitance enhancement via electrode patterning.

    Science.gov (United States)

    Ho, Tuan A; Striolo, Alberto

    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. PMID:24289370

  15. 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

  16. 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.

  17. Digital capacitance measuring system

    Science.gov (United States)

    1973-01-01

    The hardware phase of a digital capacitance measuring system is presented with the major emphasis placed on the electrical design and operation. Test results are included of the three units fabricated. The system's interface is applicable to existing requirements for the space shuttle vehicle.

  18. Dynamically Babinet-invertible metasurface: a capacitive-inductive reconfigurable filter for terahertz waves using vanadium-dioxide metal-insulator transition

    Science.gov (United States)

    Urade, Yoshiro; Nakata, Yosuke; Okimura, Kunio; Nakanishi, Toshihiro; Miyamaru, Fumiaki; Takeda, Mitsuo W.; Kitano, Masao

    2016-03-01

    This paper proposes a reconfigurable planar metamaterial that can be switched between capacitive and inductive responses using local changes in the electrical conductivity of its constituent material. The proposed device is based on Babinet's principle and exploits the singular electromagnetic responses of metallic checkerboard structures, which are dependent on the local electrical conductivity. Utilizing the heating-induced metal-insulator transition of vanadium dioxide ($\\mathrm{VO}_2$), the proposed metamaterial is designed to compensate for the effect of the substrate and is experimentally characterized in the terahertz regime. This reconfigurable metamaterial can be utilized as a switchable filter and as a switchable phase shifter for terahertz waves.

  19. Dynamically Babinet-invertible metasurface: a capacitive-inductive reconfigurable filter for terahertz waves using vanadium-dioxide metal-insulator transition

    CERN Document Server

    Urade, Yoshiro; Okimura, Kunio; Nakanishi, Toshihiro; Miyamaru, Fumiaki; Takeda, Mitsuo W; Kitano, Masao

    2016-01-01

    This paper proposes a reconfigurable planar metamaterial that can be switched between capacitive and inductive responses using local changes in the electrical conductivity of its constituent material. The proposed device is based on Babinet's principle and exploits the singular electromagnetic responses of metallic checkerboard structures, which are dependent on the local electrical conductivity. Utilizing the heating-induced metal-insulator transition of vanadium dioxide ($\\mathrm{VO}_2$), the proposed metamaterial is designed to compensate for the effect of the substrate and is experimentally characterized in the terahertz regime. This reconfigurable metamaterial can be utilized as a switchable filter and as a switchable phase shifter for terahertz waves.

  20. 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.

  1. Molecular Aspects of Capacitation

    OpenAIRE

    Gulfidan Zulfikaroglu; Hulya Ozgur; Sait Polaturkey

    2010-01-01

    Male and female gamets are derived from the primordial germ cells, which migrate from the wall of the yolk sac toward the developing gonads. Following a series of mitotic divisions these cells increase in number at the gonads. The primordial germ cells differentiate into spermatogonia and take the form of mature spermatozoa after spermotogensis and spermotogenesis at puberty. Capacitation is the reaction, which includes all of the molecular and physiological events of mature sperm to gain the...

  2. Capacitance of graphene nanoribbons

    OpenAIRE

    Shylau, A. A.; Klos, J. W.; Zozoulenko, I. V.

    2009-01-01

    We present an analytical theory for the gate electrostatics and the classical and quantum capacitance of the graphene nanoribbons (GNRs) and compare it with the exact self-consistent numerical calculations based on the tight-binding p-orbital Hamiltonian within the Hartree approximation. We demonstrate that the analytical theory is in a good qualitative (and in some aspects quantitative) agreement with the exact calculations. There are however some important discrepancies. In order to underst...

  3. Electrical capacitance clearanceometer

    Science.gov (United States)

    Hester, Norbert J. (Inventor); Hornbeck, Charles E. (Inventor); Young, Joseph C. (Inventor)

    1992-01-01

    A hot gas turbine engine capacitive probe clearanceometer is employed to measure the clearance gap or distance between blade tips on a rotor wheel and its confining casing under operating conditions. A braze sealed tip of the probe carries a capacitor electrode which is electrically connected to an electrical inductor within the probe which is inserted into a turbine casing to position its electrode at the inner surface of the casing. Electrical power is supplied through a voltage controlled variable frequency oscillator having a tuned circuit in which the probe is a component. The oscillator signal is modulated by a change in electrical capacitance between the probe electrode and a passing blade tip surface while an automatic feedback correction circuit corrects oscillator signal drift. A change in distance between a blade tip and the probe electrode is a change in capacitance therebetween which frequency modulates the oscillator signal. The modulated oscillator signal which is then processed through a phase detector and related circuitry to provide an electrical signal is proportional to the clearance gap.

  4. Ford Whitman Harris's economical lot size model

    OpenAIRE

    Erlenkotter, D

    2014-01-01

    Here we celebrate the centennial of Ford Whitman Harris's model for determining economical lot sizes, which was published in the A.W. Shaw Company's magazine Factory, The Magazine of Management in February 1913. The square-root formula derived by Harris has become one of the most cited and applied results in production and operations management. We examine the circumstances under which this result was derived, and explore the probable causes for the later obscurity of Harris's paper, which wa...

  5. Analysis of Harrell Monosodium Titanate Lot #46000824120

    Energy Technology Data Exchange (ETDEWEB)

    Taylor-Pashow, K. M.L.

    2013-01-23

    Monosodium titanate (MST) for use in the Actinide Removal Process (ARP) must be qualified and verified in advance. A single qualification sample for each batch of material is sent to SRNL for analysis, as well as a statistical sampling of verification samples. The Harrell Industries Lot #46000824120 qualification and the 16 verification samples failed to meet the specification for weight percent solids. All of the pails sampled and tested contained less than 15 wt % MST solids.

  6. Analysis of Harrell Monosodium Titanate Lot #46000908120

    Energy Technology Data Exchange (ETDEWEB)

    Taylor-Pashow, K. M.L.

    2013-01-23

    Monosodium titanate (MST) for use in the Actinide Removal Process (ARP) must be qualified and verified in advance. A single qualification sample for each batch of material is sent to SRNL for analysis, as well as a statistical sampling of verification samples. The Harrell Industries Lot #46000908120 qualification and the 16 verification samples failed to meet the specification for weight percent solids. All of the pails sampled and tested contained less than 15 wt % MST solids.

  7. [Radiotherapy Techniques and Radiation Pneumonitis: A Lot To A Little Or A Little To A Lot?].

    Science.gov (United States)

    Yu, Bingqi; Wang, Jin; Xu, Yujin; Su, Feng; Shan, Guoping; Chen, Ming

    2015-12-01

    Radiotherapy is one of the main treatment for patients with lung cancer. Three-dimensional conformal radiation therapy (3D-CRT) and intensity modulated radiation therapy (IMRT) are widely used to deliver radiation. Here, we focus on the correlations between dose distribution in lung and radiation pneumonitis according to the analysis about radiotherapy for lung cancer: A lot to a little or a little to a lot, which is the main cause of radiation pneumonitis? PMID:26706952

  8. Study on capacitance evolving mechanism of polypyrrole during prolonged cycling.

    Science.gov (United States)

    Wang, JingPing; Xu, Youlong; Wang, Jie; Zhu, Jianbo; Bai, Yang; Xiong, Lilong

    2014-02-01

    A simple model on the evolution mechanism of PPy capacitance during prolonged cycling offers a reasonably description on the rapid increase and decay of PPy capacitance in 1 M 1-ethyl-3-methylimidazolium tetrafluoroborate/propylene carbonate (EtMeImBF4/PC). The capacitance of PPy films reached a very high specific capacitance of 420 F·g(-1) after 15 cycles when they worked in 1 M MeEt3ImBF4/PC. However, the capacitance rapidly decreased to 5% after only 400 cycles. The electronic conductivity and protonation level on the nitrogen site of PPy films rapidly decreased with the increase of cyclic number. The salt of EtMeImBF4 was monitored in PPy matrix by FTIR spectra after 400 cycles. The EQCM results indicated that a lot of 1-ethyl-3-methylimidazolium cations (EtMeIm(+)) were inserted during reduction process and retained in PPy matrix. The detained EtMeIm(+) cations bonded with doped p-toluenesulfonate anions (PTS(-)) in PPy matrix or BF4(-) anions from electrolyte and formed salts. Small amount of salts in PPy matrix can open more channels of ion insertion and resulted in a very high capacitance after 15 cycles. The continuous combination of detained EtMeIm(+) cations with doping anions of PTS(-) resulted in the rapid decrease of PPy protonation level on the nitrogen site and formation of compensate semiconductor state in PPy matrix. This should be responsible for the rapid decay of PPy conductivity and capacitance. The continuous accumulation of salts resulted in the great increase of PPy internal resistance. PMID:24428582

  9. Bloch Inductance in Small-Capacitance Josephson Junctions

    International Nuclear Information System (INIS)

    We show that the electrical impedance of a small-capacitance Josephson junction also includes, in addition to the capacitive term -i/ωCB, an inductive term iωLB. 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(φ) at fixed φ=0. The effect of the Bloch inductance on the dynamics of a single junction and a one-dimensional array is described

  10. Improved capacitance sensor with variable operating frequency for scanning capacitance microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Joonhyung [PSIA Corporation, Induspia 5F, Sang-Daewon-Dong 517-13, Sungnam 462-120 (Korea, Republic of); Kim, Joonhui [PSIA Corporation, Induspia 5F, Sang-Daewon-Dong 517-13, Sungnam 462-120 (Korea, Republic of); Jeong, Jong-Hwa [PSIA Corporation, Induspia 5F, Sang-Daewon-Dong 517-13, Sungnam 462-120 (Korea, Republic of); Lee, Euy-Kyu [Department of Physics, Myongji University, Yongin, Kyunggido 449-728 (Korea, Republic of); Seok Kim, Yong [PSIA Corporation, Induspia 5F, Sang-Daewon-Dong 517-13, Sungnam 462-120 (Korea, Republic of); Kang, Chi Jung [Department of Physics, Myongji University, Yongin, Kyunggido 449-728 (Korea, Republic of); Park, Sang-il [PSIA Corporation, Induspia 5F, Sang-Daewon-Dong 517-13, Sungnam 462-120 (Korea, Republic of)]. E-mail: park@psia.co.kr

    2005-11-15

    Scanning capacitance microscopy (SCM) has been gaining attention for its capability to measure local electrical properties in doping profile, oxide thickness, trapped charges and charge dynamics. In many cases, stray capacitance produced by different samples and measurement conditions affects the resonance frequency of a capacitance sensor. The applications of conventional SCM are critically limited by the fixed operating frequency and lack of tunability in its SCM sensor. In order to widen SCM application to various samples, we have developed a novel SCM sensor with variable operating frequency. By performing variable frequency sweep over the band of 160 MHz, the SCM sensor is tuned to select the best and optimized resonance frequency and quality factor for each sample measurement. The fundamental advantage of the new variable frequency SCM sensor was demonstrated in the SCM imaging of silicon oxide nano-crystals. Typical sensitivity of the variable frequency SCM sensor was found to be 10{sup -19} F/V.

  11. Improved capacitance sensor with variable operating frequency for scanning capacitance microscopy

    International Nuclear Information System (INIS)

    Scanning capacitance microscopy (SCM) has been gaining attention for its capability to measure local electrical properties in doping profile, oxide thickness, trapped charges and charge dynamics. In many cases, stray capacitance produced by different samples and measurement conditions affects the resonance frequency of a capacitance sensor. The applications of conventional SCM are critically limited by the fixed operating frequency and lack of tunability in its SCM sensor. In order to widen SCM application to various samples, we have developed a novel SCM sensor with variable operating frequency. By performing variable frequency sweep over the band of 160 MHz, the SCM sensor is tuned to select the best and optimized resonance frequency and quality factor for each sample measurement. The fundamental advantage of the new variable frequency SCM sensor was demonstrated in the SCM imaging of silicon oxide nano-crystals. Typical sensitivity of the variable frequency SCM sensor was found to be 10-19 F/V

  12. Quantum inductance and negative electrochemical capacitance at finite frequency

    OpenAIRE

    Wang, J.; Wang, B. G.; Guo, H

    2007-01-01

    We report on theoretical investigations of frequency dependent quantum capacitance. It is found that at finite frequency a quantum capacitor can be characterized by a classical RLC circuit with three parameters: a static electrochemical capacitance, a charge relaxation resistance, and a quantum inductance. The quantum inductance is proportional to the characteristic time scale of electron dynamics and due to its existence, the time dependent current can accumulate a phase delay and becomes la...

  13. Capacitance of circular patch resonator

    International Nuclear Information System (INIS)

    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. 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.

  15. Improved Capacitive Liquid Sensor

    Science.gov (United States)

    Waldman, Francis A.

    1992-01-01

    Improved capacitive sensor used to detect presence and/or measure thickness of layer of liquid. Electrical impedance or admittance of sensor measured at prescribed frequency, and thickness of liquid inferred from predetermined theoretical or experimental relationship between impedance and thickness. Sensor is basically a three-terminal device. Features interdigitated driving and sensing electrodes and peripheral coplanar ground electrode that reduces parasitic effects. Patent-pending because first to utilize ground plane as "shunting" electrode. System less expensive than infrared, microwave, or refractive-index systems. Sensor successfully evaluated in commercial production plants to characterize emulsions, slurries, and solutions.

  16. Modelling income processes with lots of heterogeneity

    DEFF Research Database (Denmark)

    Browning, Martin; Ejrnæs, Mette; Alvarez, Javier

    2010-01-01

    We model earnings processes allowing for lots of heterogeneity across agents. We also introduce an extension to the linear ARMA model which allows the initial convergence in the long run to be different from that implied by the conventional ARMA model. This is particularly important for unit root...... this observable homogeneity, we find more latent heterogeneity than previous investigators. We show that allowance for heterogeneity makes substantial differences to estimates of model parameters and to outcomes of interest. Additionally, we find strong evidence against the hypothesis that any worker has a unit...

  17. Programmable electronic synthesized capacitance

    Science.gov (United States)

    Kleinberg, Leonard L. (Inventor)

    1987-01-01

    A predetermined and variable synthesized capacitance which may be incorporated into the resonant portion of an electronic oscillator for the purpose of tuning the oscillator comprises a programmable operational amplifier circuit. The operational amplifier circuit has its output connected to its inverting input, in a follower configuration, by a network which is low impedance at the operational frequency of the circuit. The output of the operational amplifier is also connected to the noninverting input by a capacitor. The noninverting input appears as a synthesized capacitance which may be varied with a variation in gain-bandwidth product of the operational amplifier circuit. The gain-bandwidth product may, in turn, be varied with a variation in input set current with a digital to analog converter whose output is varied with a command word. The output impedance of the circuit may also be varied by the output set current. This circuit may provide very small ranges in oscillator frequency with relatively large control voltages unaffected by noise.

  18. Analysis Of Harrell Monosodium Titanate Lot 081811

    International Nuclear Information System (INIS)

    Monosodium titanate (MST) for use in the Actinide Removal Process (ARP) must be qualified and verified in advance. A single qualification sample for each batch of material is sent to SRNL for analysis, as well as a statistical sampling of verification samples. The Harrell Industries Lot No.081811 qualification and 12 verification samples met all the requirements in the specification, with the possible exception of the geometric standard deviation for particle size. Two subsamples from the qualification sample were analyzed, giving results of 3.82 and 3.28, respectively, for the geometric standard deviation. The specification is (le)3.5. The results for both samples met the remaining particle size specifications, i.e. <10 vol% below 0.8 μm and <1 vol% above 37 μm. Filtration behavior of the current batch is expected to be near that of recent batches. SRNL recommends acceptance of this material. SRNL also recommends performing a statistical review of particle size data for the MST lots from this vendor to assess whether an improved material specification is appropriate.

  19. 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.

  20. The Online Morphology Control and Dynamic Studies on Improving Vitamin B12 Production by Pseudomonas denitrificans with Online Capacitance and Specific Oxygen Consumption Rate.

    Science.gov (United States)

    Wang, Ze-Jian; Shi, Hui-Lin; Wang, Ping

    2016-07-01

    The relationship between the morphological character of Pseudomonas denitrificans and vitamin B12 synthesis based on real-time capacitance measurement and online specific oxygen consumption rate (Q O2) control was established for enhancing vitamin B12 production. Results demonstrated that the threshold Q O2 value lower than 2.0 mmol/gDCW/l would greatly stimulate the state transfer from the cell number growth phase to the cell elongation phase and promote rapid vitamin B12 biosynthesis, while the vitamin B12 biosynthesis rate could also be inhibited when the rate of cell's length-to-width ratio (ratio-LW) was higher than 10:1. Furthermore, the optimal morphology controlling strategy was achieved based on online Q O2 control, which increases the appropriate active cell numbers at the former phase, and then control the elongation of ratio-LW no more than 10:1 at the vitamin B12 biosynthesis phase. The maximal vitamin B12 production reached 239.7 mg/l at 168 h, which was improved by 14.7 % compared with the control (208 mg/l). This online controlling strategy would be effectively applied for improving industrial vitamin B12 fermentation. PMID:27022751

  1. Hybrid Discrete Differential Evolution Algorithm for Lot Splitting with Capacity Constraints in Flexible Job Scheduling

    Directory of Open Access Journals (Sweden)

    Xinli Xu

    2013-01-01

    Full Text Available A two-level batch chromosome coding scheme is proposed to solve the lot splitting problem with equipment capacity constraints in flexible job shop scheduling, which includes a lot splitting chromosome and a lot scheduling chromosome. To balance global search and local exploration of the differential evolution algorithm, a hybrid discrete differential evolution algorithm (HDDE is presented, in which the local strategy with dynamic random searching based on the critical path and a random mutation operator is developed. The performance of HDDE was experimented with 14 benchmark problems and the practical dye vat scheduling problem. The simulation results showed that the proposed algorithm has the strong global search capability and can effectively solve the practical lot splitting problems with equipment capacity constraints.

  2. 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

  3. Efficiency of Capacitively Loaded Converters

    DEFF Research Database (Denmark)

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

    2012-01-01

    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......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...... 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....

  4. Analysis Of Harrell Monosodium Titanate Lot 120111

    International Nuclear Information System (INIS)

    Monosodium titanate (MST) for use in the Actinide Removal Process (ARP) must be qualified and verified in advance. A single qualification sample for each batch of material is sent to SRNL for analysis, as well as a statistical sampling of verification samples. The Harrell Industries Lot No.120111 qualification and the first 12 verification samples met all the requirements in the specification indicating the material is acceptable for use in the process. Analyses of Pail 125 verification sample fails the criteria for solids content and has measurably lower pH, density, and total bottle weight. The verification sample for Pail 125 was retested for weight percent solids after checking that all of the solids had been suspended. The sample again failed to meet acceptance criteria. SRNL recommends accepting Pails 1 through 120. Pails 121 through 125 should be rejected and returned to the vendor.

  5. LOTS analysis of optical diffraction in Antares

    International Nuclear Information System (INIS)

    Diffraction and aberration effects are calculated for the power-amplifier and target-system portions of the 100-kJ Antares laser fusion facility, using LOTS, a fast-Fourier-transform propagation code incorporating a model for saturating gain in CO2. Energy losses due to diffraction are found to be small compared to other losses. Diffraction 'hot spots' usually typical of propagation at low Fresnel numbers are effectively suppressed in the Antares power amplifier by gain saturation. Taking account of diffraction and aberrations over the whole optical train, the code predicts a target focal spot that has 82% of its energy in a 150-micron-diameter circle, a result essentially identical to what would be expected of the final focus mirror alone

  6. 反馈补偿对高Q值加速度计动态性能的影响%Influence of Feedback Compensation on Dynamic Property for High-Q Capacitive Accelerometers

    Institute of Scientific and Technical Information of China (English)

    戚玉婕; 车录锋; 孙腾; 王跃林

    2011-01-01

    High-Q capacitive accelerometer has low mechanical noise, which meets high resolution application requirements. However, the system with an under-damping accelerometer results in bad dynamic response needs feedback compensation in a closed-loop circuit to increase electrical damping, reduce the Q factor and improve the dynamic response. Firstly, a simplified mathematical model with time delay was built based on the simulation of MATLAB/SIMULINK. Further, step responses and Q factors of the closed loop using different compensation parameters were discussed based on the simulation and PCB board level measurements. Results show that proper compensation parameters can effectively reduce the Q factor and improve the dynamic response of the closed-loop system. Finally, how to choose proper proportionaldifferential parameters in a closed loop for the capacitive accelerometer was obtained.%高Q值MEMS电容式加速度计因具有很小的机械噪声,满足于高精度测量的需要,但欠阻尼的传感器系统动态性能较差,因此需要在闭环检测电路中通过补偿反馈模块施加电学阻尼,以降低系统Q值,改善系统的动态响应.首先通过MATLAB/SIMULINK仿真建立了带有延时的系统模型,进一步结合实际PCB板的测量,分析了不同反馈补偿参数下的阶跃响应和幅频响应曲线.实验结果表明,合适的反馈补偿参数能有效地降低系统Q值,改善动态响应.最后得出了该电容式加速度计在闭环系统下的较优比例微分参数的选择策略.

  7. Efeito da redução do tamanho de lote e de programas de Melhoria Contínua no Estoque em Processo (WIP e na Utilização: estudo utilizando uma abordagem híbrida System Dynamics - Factory Physics Effect of lot size reduction and Continuous Improvement on Work In Process and Utilization: study using a combined System Dynamics and Factory Physics approach

    Directory of Open Access Journals (Sweden)

    Moacir Godinho Filho

    2009-04-01

    Full Text Available O presente trabalho apresenta um modelo quantitativo que utiliza de forma híbrida as abordagens System Dynamics - SD (FORRESTER, 1962 e Factory Physics (HOPP; SPEARMAN, 2001 objetivando estudar o efeito conjunto de seis programas de Melhoria Contínua - CI (variabilidade na taxa de chegada, variabilidade do processo, qualidade, tempo até a falha, tempo de reparo e tempo de set up e de redução de tamanhos de lote de produção nos níveis médios de Estoque em Processo (WIP e Utilização em um ambiente produtivo com uma única máquina que processa múltiplos produtos. Os resultados dos experimentos realizados utilizando-se o modelo desenvolvido fornecem insights e subsídios que dão suporte a uma série de modernas ferramentas e filosofias de gestão da manufatura, tais como programas de redução da variabilidade do processo como, por exemplo, Seis Sigma; programas de redução de set up, como por exemplo os programas SMED (Single Minute Exchange of Die, Sistema Toyota de Produção/Manufatura Enxuta e Quick Response Manufacturing (QRM. Além disso, o modelo também serve para auxiliar na escolha de diferentes possibilidades de programas de Melhoria Contínua no chão de fábrica.This paper builds a quantitative model, which is a result of a combination of System Dynamics (FORRESTER, 1962 and Factory Physics (HOPP; SPEARMAN, 2001 approaches aiming to examine how six Continuous Improvement (CI programs (arrival variability, process variability, quality (defect rate, time to failure, repair time, and set up time, together with lot size reduction, affect Work In Process (WIP and Utilization in a multi-product, single-machine environment. Results of the paper provides support for: i the importance of implementing set up reduction programs; ii Lean Manufacturing (LM philosophy regarding the implementation of small CI programs in a lot of variables and areas of the shop floor; iii Quick Response Manufacturing (QRM philosophy regarding the

  8. 基于电容层析成像多相流检测的动态重建算法研究%Research on dynamic reconstruction algorithm based on electrical capacitance tomography in multiphase flow detection

    Institute of Scientific and Technical Information of China (English)

    王泽璞; 吴迪; 刘岩; 贾兆鹏

    2013-01-01

    In order to improve reconstruction image quality of electrical capacitance tomography ( ECT) and enhance the accuracy of ECT on-line monitor, a new generalized dynamic image reconstruction algorithm (DR) is proposed, which integrates ECT monitoring information and physical evolution information of flow fluid. This algorithm calculation process considers both the space constrains and time constrains of the flow fluid and the objective function of dynamic changing information. The results show that the algorithm calculation process not only resolves ECT inverse problem successfully,but also effectively breaks through numerical instability of ECT reconstruction results,which makes the image quality better than usual static reconstruction algorithm results.%为了提高ECT图像重建质量,提高ECT在线监测的精确性,提出了一种广义动态图像重建算法(DR),集合了ECT测量信息和流动对象的物理演变信息.该算法同时考虑被测对象的空间约束、时间约束以及动态变化信息的目标功能.动态实验研究表明,该算法成功解决ECT逆问题,有效突破了ECT图像重建的数值不稳定性,其成像质量明显好于一般的静态图像重建算法.

  9. Powder Lot Variations: A Case Study with Varget - Hodgdon Extreme

    CERN Document Server

    Courtney, Elya

    2015-01-01

    Small arms propellant distributor Hodgdon claims that rifle powders in its Extreme line have small velocity variations with both temperature changes and lot number. This paper reports on the variations in average velocity of four different lots of Hodgdon Extreme Varget tested in two .223 Remington loads. Compared to the lot with the slowest average velocity, the other three lots of powder had higher average velocities ranging from 23.4 ft/s faster up to 45.6 ft/s faster with a 69 grain Nosler Custom Competition bullet and from 7.9 ft/s faster to 15.3 ft/s with the 53 grain Hornady VMAX. The mean velocity differences between lots are slightly correlated between the two loads with a correlation coefficient of 0.54. This correlation suggests that factors other than lot to lot variations contribute significantly to the measured velocity variations. Unlike the much larger lot to lot variations that were reported previously for H4831, lot to lot variations in velocity for Varget seem consistent with Hodgdon's mark...

  10. A lot to look forward to

    CERN Multimedia

    2013-01-01

    CERN moves from momentous year to momentous year, and although 2013 will be very different for us than 2012, there is still a lot to look forward to. As I write, the proton-lead run is just getting under way, giving the LHC experiments a new kind of data to investigate. But the run will be short, and our main activity this year will be the start of the LHC’s first long shutdown.   This is the first year I can remember in which all of CERN’s accelerators will be off. The reason is that there is much to be done: the older machines need maintenance, and the LHC has to be prepared for higher energy running. That involves opening up the interconnections between each of the machine’s 1,695 main magnet cryostats, consolidating all of the 10,170 splices carrying current to the main dipole and quadrupole windings, and a range of other work to improve the machine. The CERN accelerator complex will start to come back to life in 2014, and it’s fair to say that when...

  11. Reproducibility of Elecsys anti-TSHR test results in a lot-to-lot comparison.

    Science.gov (United States)

    Hermsen, D; Eckstein, A; Schinner, S; Willenberg, H S; Thiel, A; Scherbaum, W A; Schott, M

    2010-04-01

    Most recently, a new rapid and fully-automated TSH receptor autoantibody (TRAb) assay has been established. This assay system uses the M22 human monoclonal antibody for competing against the patient's TSH receptor autoantibodies (TRAb) to be detected. The aim of our present study was to compare the reproducibility of TRAb values based on measurements with different TSH receptor preparations in a lot-to-lot comparison. For TRAb values > 2 IU/l the relative differences ranged from -9.0 to +10.0%. The mean difference was 0.28 +/- 8%. For TRAb values around the cutoff for positivity (1.75 IU/l) a higher range of relative differences from -20 up to +15% was obtained. The overall mean of differences was -0.8+/-14%. The data clearly demonstrate that the automated TRAb assay has a high stability in regard to TSH receptor preparations. PMID:20131202

  12. Capacitive Position Sensor For Accelerometer

    Science.gov (United States)

    Vanzandt, Thomas R.; Kaiser, William J.; Kenny, Thomas W.

    1995-01-01

    Capacitive position sensor measures displacement of proof mass in prototype accelerometer described in "Single-Crystal Springs for Accelerometers" (NPO-18795). Sensor is ultrasensitive, miniature device operating at ultra-high frequency and described in more detail in "Ultra-High-Frequency Capacitive Displacement Sensor," (NPO-18675). Advances in design and fabrication of prototype accelerometer also applicable to magnetometers and other sensors in which sensed quantities measured in terms of deflections of small springs.

  13. Assessing gull abundance and food availability in urban parking lots

    Science.gov (United States)

    Clark, Daniel E.; Whitney, Jillian J.; MacKenzie, Kenneth G.; Koenen, Kiana K. G.; DeStefano, Stephen

    2015-01-01

    Feeding birds is a common activity throughout the world; yet, little is known about the extent of feeding gulls in urban areas. We monitored 8 parking lots in central Massachusetts, USA, during the fall and winter of 2011 to 2013 in 4 monitoring sessions to document the number of gulls present, the frequency of human–gull feeding interactions, and the effectiveness of signage and direct interaction in reducing human-provisioned food. Parking lots were divided between “education” and “no-education” lots. In education lots, we erected signs about problems caused when people feed birds and also asked people to stop feeding birds. We did not erect signs or ask people to stop feeding birds at no-education lots. We spent >1,200 hours in parking lots (range = 136 to 200 hours per parking lot), and gulls were counted every 20 minutes. We conducted >4,000 counts, and ring-billed gulls (Lorus delawarensis) accounted for 98% of all gulls. Our educational efforts were minimally effective. There were fewer feedings (P = 0.01) in education lots during one of the monitoring sessions but significantly more gulls (P = 0.008) in education lots during 2 monitoring sessions. While there was a marginal decrease (P = 0.055) in the number of feedings after no-education lots were transformed into education lots, there was no difference in gull numbers in these lots (P = 0.16). Education appears to have some influence in reducing the number of people feeding gulls, but our efforts were not able to reduce the number of human feeders or the amount of food enough to influence the number of gulls using parking lots.

  14. The concept of chemical capacitance, A critique.

    OpenAIRE

    Trissl, H. W.

    1981-01-01

    The concept of chemical capacitance as introduced by Hong and Mauzerall (Proc. Natl. Acad. Sci. U.S.A. 1974. 71:1564) is critically reexamined. This novel capacitance was introduced to explain the time-course of flash-induced photocurrents observed in lipid bilayer membranes containing porphyrins. According to Hong and Mauzerall, the chemical capacitance results from a combination of three fundamental capacitances: the geometric membrane capacitance and the two interfacial double layer capaci...

  15. Noise Depression of Parasitic Capacitance for Frequency Detection of Micromechanical Bulk Disk Resonator

    DEFF Research Database (Denmark)

    Tang, Meng; Cagliani, Alberto; Escouflaire, Marie;

    2010-01-01

    A bulk disk resonator working in dynamic mode is used for mass detection. In the capacitive transduction scheme, the parasitic capacitance between the electrodes produces an anti resonance in the transmission curve, which distorts the phase shift at the resonant frequency and increases the...... minimal detectable mass of the sensor....

  16. Manure and wastewater management systems for open lot dairy operations

    OpenAIRE

    Sweeten, J. M.; Wolfe, M L

    1994-01-01

    Dairy industry expansion using open lot designs has impacted water quality and groundwater usage in parts of Central Texas. Field research was conducted at commercial dairy farms in Erath County, Texas, to develop improved design criteria for storage, treatment, and land application systems for open lot dairies. Water use and wastewater from milking parlors were monitored along with runoff from open lots. Water use for milk sanitation and manure removal averaged 148 L per cow per day. Two-sta...

  17. Lot-sizing algorithms with applications to engineering and economics

    DEFF Research Database (Denmark)

    Vidal, Rene Victor Valqui; Ferreira, Jose S.

    1984-01-01

    The paper presents two new solution procedures for a deterministic lot size problem, a matrix algorithm and a heuristic matrix method. The algorithm is based on the dual of a linear programming model formulation of the lot size problem, and it provides optimal solutions even in the general case of...

  18. Time bucket size and lot-splitting approach

    NARCIS (Netherlands)

    Riezebos, Jan

    2002-01-01

    We address the problem of lot splitting for various time bucket lengths in MRP systems. Two approaches for lot splitting can be applied: either use the same (equal) or a variable number of subbatches. Equal subbatching strategies have logistical and computational advantages. Literature states that v

  19. 7 CFR 800.98 - Weighing grain in combined lots.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Weighing grain in combined lots. 800.98 Section 800.98... Provisions and Procedures § 800.98 Weighing grain in combined lots. (a) General. The weighing of bulk or sacked grain loaded aboard, or being loaded aboard, or unloaded from two or more carriers as a...

  20. Studi Kasus Perbandingan antara Lot-for-Lot dan Economic Order Quantity Sebagai Metode Perencanaan Penyediaan Bahan Baku

    Directory of Open Access Journals (Sweden)

    Oegik Soegihardjo

    1999-01-01

    Full Text Available Production and material requirements planning are interrelated. The number of required material depends on the quantity of products for a certain period. The are some methods for material requirements planning. Two of them are lot-for-lot and economic order quantity. Those two methods will be apllied to impeller requirements planning for centrifugal pumps and evaluated to determine which one is more appropriate for the case being studied. Those methods are chosen because each of them has different characteristic in determination of lot's quantity. In lot-for-lot the determination of quantity of the impeller is based on the requirements for single period. In economic order quantity the determination of quantity of the impeller is based on expected requirements. Abstract in Bahasa Indonesia : Perencanaan produksi dan penyediaan bahan baku merupakan dua hal yang berkaitan. Berapa banyak bahan baku yang harus disediakan, ditentukan oleh berapa jumlah produk yang akan dibuat pada suatu periode tertentu. Metode perencanaan untuk penyediaan bahan baku ada beberapa macam. Dua di antara metode perencanaan penyiapan bahan baku adalah 'lot-for-lot' dan 'economic order quantity'. Dua metode tersebut akan dipakai untuk perencanaan penyediaan sudu pompa sentrifugal untuk dievaluasi mana yang lebih sesuai untuk kasus penyediaan sudu pompa sentrifugal tersebut. Dua metode ini dipilih karena kedua metode tersebut mempunyai karakter yang berbeda dalam penyediaan kebutuhan bahan baku (bahan baku dalam kasus ini adalah impeller pompa. Pada metode 'lot-for-lot' penentuan jumlah sediaan bahan baku ditetapkan sedemikian rupa untuk memenuhi kebutuhan bersih satu periode tunggal. Sedangkan pada metode 'economic order quantity' penentuan sediaan bahan baku ditetapkan berdasarkan kebutuhan yang diperkirakan (expected requirements. Kata kunci: kebutuhan bahan baku, kebutuhan bersih, 'lot-for-lot', 'economic order quantity'.

  1. Theory of substrate, Zeeman, and electron-phonon interaction effects on the quantum capacitance in graphene

    KAUST Repository

    Tahir, M.

    2013-12-10

    Since the discovery of graphene, a lot of interest has been attracted by the zeroth Landau level, which has no analog in the conventional two dimensional electron gas. Recently, lifting of the spin and valley degeneracies has been confirmed experimentally by capacitance measurements, while in transport experiments, this is difficult due to the scattering in the device. In this context, we model interaction effects on the quantum capacitance of graphene in the presence of a perpendicular magnetic field, finding good agreement with experiments. We demonstrate that the valley degeneracy is lifted by the substrate and by Kekule distortion, whereas the spin degeneracy is lifted by Zeeman interaction. The two cases can be distinguished by capacitance measurements.

  2. Driven shielding capacitive proximity sensor

    Science.gov (United States)

    Vranish, John M. (Inventor); McConnell, Robert L. (Inventor)

    2000-01-01

    A capacitive proximity sensing element, backed by a reflector driven at the same voltage as and in phase with the sensor, is used to reflect the field lines away from a grounded robot arm towards an intruding object, thus dramatically increasing the sensor's range and sensitivity.

  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. Active Targets For Capacitive Proximity Sensors

    Science.gov (United States)

    Jenstrom, Del T.; Mcconnell, Robert L.

    1994-01-01

    Lightweight, low-power active targets devised for use with improved capacitive proximity sensors described in "Capacitive Proximity Sensor Has Longer Range" (GSC-13377), and "Capacitive Proximity Sensors With Additional Driven Shields" (GSC-13475). Active targets are short-distance electrostatic beacons; they generate known alternating electro-static fields used for alignment and/or to measure distances.

  6. Effects of stray capacitance to ground in bipolar water impedance measurements based on capacitive electrodes

    OpenAIRE

    Pallàs Areny, Ramon; Aliau Bonet, Carles

    2015-01-01

    Liquid impedance measurements based on capacitive (or contactless) electrodes Overcome electrode polarization problems but are affected by stray capacitance from the material being measured to ground, the same as measurements with direct-contact electrodes. This study shows that the effects of that capacitance depend on the impedance being measured and for bipolar impedance measurements they increase when the ratio between that stray capacitance and lectrode capacitance increases.

  7. Parking Lots at Little Bighorn Battlefield National Monument, Montana

    Data.gov (United States)

    National Park Service, Department of the Interior — This is a vector polygon file showing the parking lots at Little Bighorn Battlefield National Monument (LIBI). The coordinates for this dataset were collected using...

  8. Automatic parking lot occupancy computation using motion tracking

    Science.gov (United States)

    Justo, Francisco; Kalva, Hari; Raviv, Daniel

    2014-03-01

    Nowadays it is very hard to find available spots in public parking lots and even harder in public facilities such as universities and sports venues. A system that provides drivers with parking availability and parking lot occupancy will allow users find a parking space much easier and faster. This paper presents a system for automatic parking lot occupancy computation using motion tracking. Methods for complexity reduction are presented. The system showed approximately 96% accuracy in determining parking lot occupancy. We showed that by optimizing the resolution and bitrate of the input video, we can reduce the complexity by 70% and still achieved over 90% of accuracy. The results showed that high quality video is not necessary for the proposed algorithm to obtain accurate results.

  9. A New Fully Differential CMOS Capacitance to Digital Converter for Lab-on-Chip Applications.

    Science.gov (United States)

    Nabovati, Ghazal; Ghafar-Zadeh, Ebrahim; Mirzaei, Maryam; Ayala-Charca, Giancarlo; Awwad, Falah; Sawan, Mohamad

    2015-06-01

    In this paper, we present a new differential CMOS capacitive sensor for Lab-on-Chip applications. The proposed integrated sensor features a DC-input ΣΔ capacitance to digital converter (CDC) and two reference and sensing microelectrodes integrated on the top most metal layer in 0.35 μm CMOS process. Herein, we describe a readout circuitry with a programmable clocking strategy using a Charge Based Capacitance Measurement technique. The simulation and experimental results demonstrate a high capacitive dynamic range of 100 fF-110 fF, the sensitivity of 350 mV/fF and the minimum detectable capacitance variation of as low as 10 aF. We also demonstrate and discuss the use of this device for environmental applications through various chemical solvents. PMID:25134090

  10. Intelligent Simulation-based Lot Scheduling of Photolithography Toolsets in a Wafer Fabrication Facility

    OpenAIRE

    Arisha, Amr; Young, Paul

    2004-01-01

    Scheduling of a semiconductor manufacturing facility is one of the most complex tasks encountered. Confronted with a high technology product market, semiconductor manufacturing is increasingly more dynamic and competitive in the introduction of new products in shorter time intervals. Photolithography, being one of the processes repeated often, is a fabrication bottleneck. Lot scheduling within photolithography is a challenging activity where substantial improvements in factory performance can...

  11. Evaluation of the synthesis of six lots of HNS I

    Energy Technology Data Exchange (ETDEWEB)

    Stull, T.W.

    1978-09-01

    The analytical results of six lots of high purity 2,2',4,4',6,6'-hexanitrostilbene (HNS I) synthesized by the Development Division, Mason and Hanger, Pantex Plant are discussed. A total of approximately 130 kg was produced in lot sizes ranging from 5.2 to 46.4 kg. The results clearly indicate the excellent reproducibility of the process and high purity of the final product.

  12. Camp Pendleton Saves 91% in Parking Lot Lighting

    Energy Technology Data Exchange (ETDEWEB)

    None

    2016-01-01

    Case study describes how Camp Pendleton Marine Corps Base replaced high-pressure sodium (HPS) fixtures in one parking lot with high-efficiency induction fixtures for 91% savings in energy use and $5,700 in cost savings annually. This parking lot is estimated to have a simple payback of 2.9 years. Sitewide up-grades yielded annual savings of 1 million kWh.

  13. Full-bridge capacitive extensometer

    Science.gov (United States)

    Peters, Randall D.

    1993-08-01

    Capacitive transducers have proven to be very effective sensors of small displacements, because of inherent stability and noninvasive high resolution. The most versatile ones have been those of a differential type, in which two elements are altered in opposite directions in response to change of the system parameter being monitored. Oftentimes, this differential pair has been incorporated into a bridge circuit, which is a useful means for employing synchronous detection to improve signal to noise ratios. Unlike previous differential capacitive dilatometers which used only two active capacitors, the present sensor is a full-bridge type, which is well suited to measuring low-level thermal expansions. This analog sensor is capable of 0.1 μm resolution anywhere within a range of several centimeters, with a linearity of 0.1%. Its user friendly output can be put on a strip chart recorder or directed to a computer for sophisticated data analysis.

  14. Water desalination via capacitive deionization

    OpenAIRE

    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 charged electrodes, commonly composed of highly porous carbon materials. The CDI community has grown exponentially over the past decade, driving tremendous advances via new cell architectures and system de...

  15. Capacitive de-ionization electrode

    Energy Technology Data Exchange (ETDEWEB)

    Daily, III, William D.

    2013-03-19

    An electrode "cell" for use in a capacitive deionization (CDI) reactor consists of the electrode support structure, a non-reactive conductive material, the electrode accompaniment or substrate and a flow through screen/separator. These "layers" are repeated and the electrodes are sealed together with gaskets between two end plates to create stacked sets of alternating anode and cathode electrodes in the CDI reactor.

  16. Capacitively-Heated Fluidized Bed

    Science.gov (United States)

    Mchale, E. J.

    1982-01-01

    Fluidized-bed chamber in which particles in bed are capacitively heated produces high yields of polycrystalline silicon for semiconductor devices. Deposition of unrecoverable silicon on chamber wall is reduced, and amount of recoverable silicon depositing on seed particles in bed is increased. Particles also have a size and density suitable for direct handling without consolidation, unlike silicon dust produced in heated-wall chambers.

  17. Radiotherapy Techniques and Radiation Pneumonitis: 
A Lot To A Little Or A Little To A Lot?

    Directory of Open Access Journals (Sweden)

    Bingqi YU

    2015-12-01

    Full Text Available Radiotherapy is one of the main treatment for patients with lung cancer. Three-dimensional conformal radiation therapy (3D-CRT and intensity modulated radiation therapy (IMRT are widely used to deliver radiation. Here, we focus on the correlations between dose distribution in lung and radiation pneumonitis according to the analysis about radiotherapy for lung cancer: A lot to a little or a little to a lot, which is the main cause of radiation pneumonitis?

  18. An approach to evaluate capacitance, capacitive reactance and resistance of pivoted pads of a thrust bearing

    Science.gov (United States)

    Prashad, Har

    1992-07-01

    A theoretical approach is developed for determining the capacitance and active resistance between the interacting surfaces of pivoted pads and thrust collar, under different conditions of operation. It is shown that resistance and capacitive reactance of a thrust bearing decrease with the number of pads times the values of these parameters for an individual pad, and that capacitance increases with the number of pads times the capacitance of an individual pad. The analysis presented has a potential to diagnose the behavior of pivoted pad thrust bearings with the angle of tilt and the ratio of film thickness at the leading to trailing edge, by determining the variation of capacitance, resistance, and capacitive reactance.

  19. Macroscopic quantum tunneling in a stack of capacitively-coupled intrinsic Josephson junctions

    Science.gov (United States)

    Koyama, Tomio; Machida, Masahiko

    2008-04-01

    A macroscopic quantum theory for the phase dynamics in capacitively-coupled intrinsic Josephson junctions (IJJ's) is constructed. We quantize the capacitively-coupled IJJ model in terms of the canonical quantization method. The multi-junction effect for the macroscopic quantum tunneling (MQT) to the first resistive branch is clarified. It is shown that the escape rate is greatly enhanced by the capacitive coupling between junctions. We also discuss the origin of the N2 -enhancement in the escape rate observed in the uniformly switching in Bi-2212 IJJ's.

  20. Encapsulation of Capacitive Micromachined Ultrasonic Transducers Using Viscoelastic Polymer

    OpenAIRE

    Lin, Der-Song; Zhuang, Xuefeng; Wong, Serena H.; Kupnik, Mario; Khuri-Yakub, Butrus Thomas

    2010-01-01

    The packaging of a medical imaging or therapeutic ultrasound transducer should provide protective insulation while maintaining high performance. For a capacitive micromachined ultrasonic transducer (CMUT), an ideal encapsulation coating would therefore require a limited and predictable change on the static operation point and the dynamic performance, while insulating the high dc and dc actuation voltages from the environment. To fulfill these requirements, viscoelastic materials, such as poly...

  1. Effect of electrode thickness variation on operation of capacitive deionization

    OpenAIRE

    Porada, S.; Bryjak, M.; Wal, van der, A.C.; Biesheuvel, P. M.

    2012-01-01

    In capacitive deionization (CDI) water is desalinated by applying an electrical field between two porous electrodes placed on either side of a spacer channel that transports the aqueous solution. In this work we investigate the equilibrium salt adsorption and the dynamic development of the effluent salt concentration in time, both as function of spacer and electrode thicknesses. The electrode thickness will be varied in a symmetric manner (doubling both electrodes) and in an asymmetric manner...

  2. Shelf life extension for the lot AAE nozzle severance LSCs

    Science.gov (United States)

    Cook, M.

    1990-01-01

    Shelf life extension tests for the remaining lot AAE linear shaped charges for redesigned solid rocket motor nozzle aft exit cone severance were completed in the small motor conditioning and firing bay, T-11. Five linear shaped charge test articles were thermally conditioned and detonated, demonstrating proper end-to-end charge propagation. Penetration depth requirements were exceeded. Results indicate that there was no degradation in performance due to aging or the linear shaped charge curving process. It is recommended that the shelf life of the lot AAE nozzle severance linear shaped charges be extended through January 1992.

  3. Improving aggregate behavior in parking lots with appropriate local maneuvers

    KAUST Repository

    Rodriguez, Samuel

    2013-11-01

    In this paper we study the ingress and egress of pedestrians and vehicles in a parking lot. We show how local maneuvers executed by agents permit them to create trajectories in constrained environments, and to resolve the deadlocks between them in mixed-flow scenarios. We utilize a roadmap-based approach which allows us to map complex environments and generate heuristic local paths that are feasible for both pedestrians and vehicles. Finally, we examine the effect that some agent-behavioral parameters have on parking lot ingress and egress. © 2013 IEEE.

  4. 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

  5. Nucleotide Capacitance Calculation for DNA Sequencing

    OpenAIRE

    Lu, Jun-Qiang; Zhang, X.-G.

    2008-01-01

    Using a first-principles linear response theory, the capacitance of the DNA nucleotides, adenine, cytosine, guanine, and thymine, are calculated. The difference in the capacitance between the nucleotides is studied with respect to conformational distortion. The result suggests that although an alternate current capacitance measurement of a single-stranded DNA chain threaded through a nanogap electrode may not be sufficient to be used as a standalone method for rapid DNA sequencing, the capaci...

  6. Electrical Capacitance Volume Tomography: Design and Applications

    OpenAIRE

    Warsito Warsito; Liang-Shih Fan; Qussai Marashdeh; Fei Wang

    2010-01-01

    This article reports recent advances and progress in the field of electrical capacitance volume tomography (ECVT). ECVT, developed from the two-dimensional electrical capacitance tomography (ECT), is a promising non-intrusive imaging technology that can provide real-time three-dimensional images of the sensing domain. Images are reconstructed from capacitance measurements acquired by electrodes placed on the outside boundary of the testing vessel. In this article, a review of progress on capa...

  7. Electrochemical capacitance of a leaky nanocapacitor

    OpenAIRE

    Zhao, X; Guo, H; Wang, J.

    1999-01-01

    We report a detailed theoretical investigation on electrochemical capacitance of a nanoscale capacitor where there is a DC coupling between the two conductors. For this ``leaky'' quantum capacitor, we have derived general analytic expressions of the linear and second order nonlinear electrochemical capacitance within a first principles quantum theory in the discrete potential approximation. Linear and nonlinear capacitance coefficients are also derived in a self-consistent manner without the ...

  8. 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.

  9. Detection of Telomerase Activity Using Capacitance Measurements

    Science.gov (United States)

    Kang, Bong Keun; Lee, Ri Mi; Choi, Ahmi; Jung, Hyo-Il; Yoo, Kyung-Hwa

    2007-03-01

    Telomerase activity has been found in about 85% cancer cells, while no activity observed in normal cells, so that telomerase has been proposed as a marker for cancer detection. Here, we describe electrical detection of telomerase activity using capacitance measurements. We have investigated the length dependence of capacitance on DNA solutions and found that the capacitance of DNA solutions were dependent on the DNA length. In addition, upon adding telomerase into the solution of telomeric substrate primer, the capacitance was observed to change as a function of time due to the telomeric elongation. These results suggest that this novel nanosensor may be used for rapid detection of telomerase activity.

  10. Module Eleven: Capacitance; Basic Electricity and Electronics Individualized Learning System.

    Science.gov (United States)

    Bureau of Naval Personnel, Washington, DC.

    In this module the student will learn about another circuit quantity, capacitance, and discover the effects of this component on circuit current, voltage, and power. The module is divided into seven lessons: the capacitor, theory of capacitance, total capacitance, RC (resistive-capacitive circuit) time constant, capacitive reactance, phase and…

  11. Capacitance Measurement with a Sigma Delta Converter for 3D Electrical Capacitance Tomography

    Science.gov (United States)

    Nurge, Mark

    2005-01-01

    This paper will explore suitability of a newly available capacitance to digital converter for use in a 3D Electrical Capacitance Tomography system. A switch design is presented along with circuitry needed to extend the range of the capacitance to digital converter. Results are then discussed for a 15+ hour drift and noise test.

  12. Ultrahigh Temperature Capacitive Pressure Sensor

    Science.gov (United States)

    Harsh, Kevin

    2014-01-01

    Robust, miniaturized sensing systems are needed to improve performance, increase efficiency, and track system health status and failure modes of advanced propulsion systems. Because microsensors must operate in extremely harsh environments, there are many technical challenges involved in developing reliable systems. In addition to high temperatures and pressures, sensing systems are exposed to oxidation, corrosion, thermal shock, fatigue, fouling, and abrasive wear. In these harsh conditions, sensors must be able to withstand high flow rates, vibration, jet fuel, and exhaust. In order for existing and future aeropropulsion turbine engines to improve safety and reduce cost and emissions while controlling engine instabilities, more accurate and complete sensor information is necessary. High-temperature (300 to 1,350 C) capacitive pressure sensors are of particular interest due to their high measurement bandwidth and inherent suitability for wireless readout schemes. The objective of this project is to develop a capacitive pressure sensor based on silicon carbon nitride (SiCN), a new class of high-temperature ceramic materials, which possesses excellent mechanical and electric properties at temperatures up to 1,600 C.

  13. Automotive Parking Lot and Theft Detection through Image Processing

    Directory of Open Access Journals (Sweden)

    2013-10-01

    Full Text Available Automotive parking lot and theft detection through image processing is a smart parking lot which will save time for the owner to park his car in a more organized way and also prevent theft of the car. It is a technology to optimize the checkout process by analysing a database of images of number plates of cars. The heart of the project is based on image processing. The images of number plates will be detected by Matlab and a picture of the driver will be saved in a similar database. As soon as both the images are saved, the garage entrance pole will shift 90 degrees upward using a DC MOTOR and will remain in that position for 30 seconds to allow the car to enter. After 30 seconds it will return back to its previous position. When the car exits the earlier steps will be repeated and Matlab will match both the images that were taken during entering and leaving. Meanwhile the seven segment display will show that a car has left the parking lot, by decrementing a number from its display. The cars are controlled by a microcontroller which is also able to detect and display if a vacant parking space is available. If there is no vacancy a red LED lights up, where as a green LED is used to display presence of parking space along with how many parking spots are available. It is applicable to be used in super market car parking lots and also apartment garages.

  14. The conquest of the terrestrial surface: a lot earlier?

    International Nuclear Information System (INIS)

    The author describes the importance from the discovery of two North American scientists when finding evidences of a possible invasion of life in the terrestrial surface a lot earlier of known until now is accepted, when found indications of organisms like bacteria or algae in rocks between 800 and 1200 million years

  15. Full-Depth Asphalt Pavements for Parking Lots and Driveways.

    Science.gov (United States)

    Asphalt Inst., College Park, MD.

    The latest information for designing full-depth asphalt pavements for parking lots and driveways is covered in relationship to the continued increase in vehicle registration. It is based on The Asphalt Institute's Thickness Design Manual, Series No. 1 (MS-1), Seventh Edition, which covers all aspects of asphalt pavement thickness design in detail,…

  16. 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...

  17. Dissecting graphene capacitance in electrochemical cell

    International Nuclear Information System (INIS)

    Quantum capacitance of graphene plays a significant role for graphene's applications in electrochemical devices and sensors, while the determination of these basic characters of Dirac point, Fermi energy, quantum capacitance, etc is still a subject of considerable debate in both experiments and simulations. Here, we report joint first-principles/continuum calculations (JFPCCs) on a monolayer graphene electrode immersed in an electrolyte coupled with a reference electrode under an applied potential. The JFPCCs gave the Fermi level, charge density on graphene, Dirac point energy, electrostatic potential, electric double layer etc as a function of the applied potential with respect to the reference electrode. These results revealed the strongly coupled relationship between Fermi level change and Dirac point shift in electrochemical cell. The total capacitance of the electrochemical cell was dissected into the quantum capacitance of the graphene electrode and the capacitance of the electric double layer. Furthermore, simple and analytic formulas were proposed for the three capacitances, which predicted, in sufficient accuracy, the behavior of capacitance versus potential. These findings deepen the understanding of quantum capacitance of graphene, which will stimulate novel experimental and theoretical studies and boost the applications of graphene in electrochemical and energy areas

  18. Quantum capacitance of the monolayer graphene

    OpenAIRE

    Cheremisin, M. V.

    2012-01-01

    The quantum capacitance of the monolayer graphene for arbitrary carrier density, magnetic field and temperature is found. The density dependence of the quantum capacitance is analyzed for magnetic field(temperature) is fixed(varied) and vice versa. The theory is compared with the experimental data.

  19. Capacitance densitometer for flow regime identification

    Science.gov (United States)

    Shipp, Jr., Roy L.

    1978-01-01

    This invention relates to a capacitance densitometer for determining the flow regime of a two-phase flow system. A two-element capacitance densitometer is used in conjunction with a conventional single-beam gamma densitometer to unambiguously identify the prevailing flow regime and the average density of a flowing fluid.

  20. Capacitance-coupled wiper increases potentiometer life

    Science.gov (United States)

    Dimeff, J.

    1968-01-01

    Capacitively-coupled wiper reduces the friction between the sliding contact and the potentiometer element in conventional potentiometers. A small preamplifier employed close to the wiper reduces errors caused by output cable capacitance. The device is friction free with resultant low wear and has high speed and high resolution.

  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. Energy-Efficient Capacitive-Sensor Interfaces

    OpenAIRE

    Z. Tan

    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.

  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. Concentration Fluctuations and Capacitive Response in Dense Ionic Solutions

    CERN Document Server

    Uralcan, Betul; Debenedetti, Pablo G; Limmer, David T

    2016-01-01

    We use molecular dynamics simulations in a constant potential ensemble to study the effects of solution composition on the electrochemical response of a double layer capacitor. We find that the capacitance first increases with ion concentration following its expected ideal solution behavior but decreases upon approaching a pure ionic liquid. The non-monotonic behavior of the capacitance as a function of ion concentration results from the competition between the independent motion of solvated ions in the dilute regime and solvation fluctuations in the concentrated regime. When charge fluctuations induced by correlated ion-solvent fluctuations are large relative to those induced by the pure ionic liquid, such non-monotonic behavior is expected to be generic.

  5. Conductivity Effect on the Capacitance Measurement of a Parallel-Plate Capacitive Sensor System

    Directory of Open Access Journals (Sweden)

    Peyman Azimi

    2011-01-01

    Full Text Available In this article design and operation of a parallel-plate capacitive sensor based on the dielectric capacitance and conductance change of the gap medium is reported. The designed system was used to determine characteristics of different water liquids as a result of the capacitance variations. The air gap capacitance is measured and then by filling the gap with a liquid the capacitance is monitored for different liquids. Proposed sensor is used for the distilled, tap, boiled, and salt water measurements and the capacitance results are compared. A big difference about 45.5 :F in capacitance values for the salt and distilled water shows a high sensitivity, which can be used to recognize different water liquids. The experimental results are promising for water liquids and verify the successful operation of such a device as a liquid sensor, a useful method for checking the electrical quality of the water that is required for different applications.

  6. Molecular Insights into Carbon Nanotube Supercapacitors: Capacitance Independent of Voltage and Temperature

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Guang [Vanderbilt Univ., Nashville, TN (United States). Dept. of Chemical and Biomolecular Engineering; Li, Song [Vanderbilt Univ., Nashville, TN (United States). Dept. of Chemical and Biomolecular Engineering; Atchison, Jennifer S. [Leibniz Inst. for New Materials (INM), Saarbrücken (Germany); Presser, Volker [Leibniz Inst. for New Materials (INM), Saarbrücken (Germany); Cummings, Peter T. [Vanderbilt Univ., Nashville, TN (United States). Dept. of Chemical and Biomolecular Engineering; Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Science

    2013-04-12

    Molecular dynamics (MD) simulations of supercapacitors with single-walled carbon nanotube (SWCNT) electrodes in room-temperature ionic liquids were performed to investigate the influences of the applied electrical potential, the radius/curvature of SWCNTs, and temperature on their capacitive behavior. It is found that (1) SWCNTs-based supercapacitors exhibit a near-flat capacitance–potential curve, (2) the capacitance increases as the tube radius decreases, and (3) the capacitance depends little on the temperature. We report the first MD study showing the influence of the electrode curvature on the capacitance–potential curve and negligible dependence of temperature on capacitance of tubular electrode. The latter is in good agreement with recent experimental findings and is attributed to the similarity of the electrical double layer (EDL) microstructure with temperature varying from 260 to 400 K. The electrode curvature effect is explained by the dominance of charge overscreening and increased ion density per unit area of electrode surface.

  7. A hybrid flowshop scheduling model considering dedicated machines and lot-splitting for the solar cell industry

    Science.gov (United States)

    Wang, Li-Chih; Chen, Yin-Yann; Chen, Tzu-Li; Cheng, Chen-Yang; Chang, Chin-Wei

    2014-10-01

    This paper studies a solar cell industry scheduling problem, which is similar to traditional hybrid flowshop scheduling (HFS). In a typical HFS problem, the allocation of machine resources for each order should be scheduled in advance. However, the challenge in solar cell manufacturing is the number of machines that can be adjusted dynamically to complete the job. An optimal production scheduling model is developed to explore these issues, considering the practical characteristics, such as hybrid flowshop, parallel machine system, dedicated machines, sequence independent job setup times and sequence dependent job setup times. The objective of this model is to minimise the makespan and to decide the processing sequence of the orders/lots in each stage, lot-splitting decisions for the orders and the number of machines used to satisfy the demands in each stage. From the experimental results, lot-splitting has significant effect on shortening the makespan, and the improvement effect is influenced by the processing time and the setup time of orders. Therefore, the threshold point to improve the makespan can be identified. In addition, the model also indicates that more lot-splitting approaches, that is, the flexibility of allocating orders/lots to machines is larger, will result in a better scheduling performance.

  8. Analysis of Innovative and Modern Technology of Parking Lots

    Directory of Open Access Journals (Sweden)

    Jonas Damidavičius

    2016-04-01

    Full Text Available Management of urban communication systems and ensuring of residents demands are the main tasks of the sustainable city development. One of the most important areas that forms better urban image is sustainable mobility development. It has influence on social, economical viability and environmental quality. Nowadays, intensive rhythm of life and increasing transport demands, usage of cars become a significant problem which regards the air and noise pollution and lack of parking spaces. Due to the daily impossibility of residents to find vacant parking spaces influence unproper usage of public spaces, streets, pedestrian and bicycle paths, children backgrounds, green areas and other territories. This report provides an overview of concepts of parking lots and their technology, and property usage in city center, middle zones, suburban territories and as well an analysis of the evolution of parking spaces. The report presents modern and innovative concepts of parking lots, which improves quality of communication and life in city and improves architectural environment.

  9. LOT-G3: Plasma Lamp, Ozonator and CW transmitter

    CERN Document Server

    Gobato, Ricardo; Gobato, Alekssander

    2015-01-01

    The LOT-G3 is designed to be a versatile equipment that perform several simple experiments for use in helping the physics classes for high school. Easy construction, low cost, using easily accessible materials. Its construction involves simple practices and knowledge of electromagnetism. It has the function of a plasma globe to demonstrate the ionization of a low pressure gas, as well as the formation of magnetic field. Can be used as sanitizer closed environments such as automotive vehicles in ozonator function, demonstrating the ionization of oxygen in the atmosphere, producing ozone, essential to life on earth. And as a sparks transmitter, low power, low frequency modulated continuous wave in (CW), for signals in Morse code. Therefore the equipment here called LOT-G3, has three functions: a plasma lamp, ozonator and CW transmitter.

  10. A JOINT PRICING, LOT-SIZING AND SUPPLIER SELECTION MODEL

    OpenAIRE

    Rezaei, Jafar; Davoodi, Mansoor

    2011-01-01

    Abstract In this paper, we integrate the three strategies that are important to most firms, namely pricing, lot-sizing and supplier selection. Combining the three objectives of total profit, inconsistency and deficiency with a set of constraints, we formulate this integrated problem as a multi-objective non-linear programming model, proposing a genetic algorithm (NSGA-II) that provides decision-makers with a number of Pareto-optimal solutions, one of which can be selected on the ba...

  11. Powder characterization of HNS-II, Lot No. ENB-63

    Energy Technology Data Exchange (ETDEWEB)

    Duncan, A.A.; Quinlin, W.T.

    1991-07-01

    This is a compilation of powder characterization data generated by Pantex on hexanitrostilbene type II (HNS-II) Lot No. ENG-63 recrystallized by Ensign-Bickford Aerospace. Characterization includes particle size distribution, specific surface area, N,N-dimethylformamide (DMF) insoluble particles, melting point, Differential Scanning Calorimetry (DSC) endotherm and exotherm temperatures, purity determined by liquid chromatography, and photomicrographs of the bulk powder and foreign particles.

  12. Make 'em Laugh (& They'll Learn a Lot More)

    Science.gov (United States)

    Done, Phillip

    2006-01-01

    Learning and laughter go hand in hand. Teachers certainly do not need to be stand-up comedians and spew out one-liners or dress up like clowns to make their classes fun. A little comedy can bring a lot of joy and learning opportunities to the classroom. In this article, the author shares several strategies on how teachers can put in laughter into…

  13. COAP BASED ACUTE PARKING LOT MONITORING SYSTEM USING SENSOR NETWORKS

    Directory of Open Access Journals (Sweden)

    R. Aarthi

    2014-06-01

    Full Text Available Vehicle parking is the act of temporarily maneuvering a vehicle in to a certain location. To deal with parking monitoring system issue such as traffic, this paper proposes a vision of improvements in monitoring the vehicles in parking lots based on sensor networks. Most of the existing paper deals with that of the automated parking which is of cluster based and each has its own overheads like high power, less energy efficiency, incompatible size of lots, space. The novel idea in this work is usage of CoAP (Constrained Application Protocol which is recently created by IETF (draft-ietf-core-coap-18, June 28, 2013, CoRE group to develop RESTful application layer protocol for communications within embedded wireless networks. This paper deals with the enhanced CoAP protocol using multi hop flat topology, which makes the acuters feel soothe towards parking vehicles. We aim to minimize the time consumed for finding free parking lot as well as increase the energy efficiency

  14. 50 CFR 260.61 - Sampling plans and procedures for determining lot compliance.

    Science.gov (United States)

    2010-10-01

    ... shall be selected from each lot in the exact number of sample units indicated for the lot size in the... requirements) in the sample does not exceed the acceptance number prescribed for the sample size the lot meets...) in the sample exceeds the acceptance number prescribed for the sample size the lot fails...

  15. 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.

  16. 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.

  17. 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

  18. The economic production lot size model with several production rates

    DEFF Research Database (Denmark)

    Larsen, Christian

    should be chosen in the interval between the demand rate and the production rate, which minimize unit production costs, and should be used in an increasing order. Then, given the production rates, we derive closed form solutions for the optimal runtimes as well as the minimum average cost. Finally we......We study an extension of the economic production lot size model, where more than one production rate can be used during a cycle. The production rates and their corresponding runtimes are decision variables. We decompose the problem into two subproblems. First, we show that all production rates...... derive a near-optimal solution to the general problem....

  19. Potentiels urbains et îlots de chaleur

    OpenAIRE

    Cornélis, Bernard; Binard, Marc; Istvan NADASDI

    1998-01-01

    The present contribution aims at answering in a quantitative way the question: is there a relationship between urban heat island and urban potential ? If such a relationship exits, it tries to quantify it and to answer the following questions : - would the potential model allow the representation of the heat island phenomenon ? - If so, in which conditions ? La présente contribution vise à répondre de manière quantitative à la question: existe-t-il une relation entre les îlots de chaleur ...

  20. Role of ions and ion channels in capacitation and acrosome reaction of spermatozoa

    Institute of Scientific and Technical Information of China (English)

    SharadBPurohit; MaliniLaloraya; G.pradeepkumar

    1999-01-01

    Capacitation and acrosome reaction are important prerequisites of the fertilization process. Capacitation is a highlycomplex phenomenon occurring in the female genital tract, rendering the spermatozoa capable of binding and fusionwith the oocyte. During capacitation various biochemical and biophysical changes occur in the spermatozoa and thespermatozoal membranes. Ions and ion channels also play important roles in governing the process of capacitation bychanging the fluxes of different ions which in turn controls various characteristics of capacitated spermatozoa. Alongwith the mobilization of ions the generation of free radicals and efflux of cholesterol also plays an impo~.nt role in thecapacitation state of the spermatozoa. The generation of free radical and efflux of cholesterol change the mechano-dynamic properties of the membrane by oxidation of the polyunsaturated lipids and by generating the cholesterol freepatches. The process of capacitation renders the spermatozoa responsive to the inducers of the acrosome reaction. Theglycoprotein zona pellucida 3 (ZP3) of the egg coat zona pellucida is the potent physiological stimulator of the acro-some reaction; progesterone, a major component of the follicular fluid, is also an inducer of the acrosome reaction.The inducers of the acrosome reaction cause the activation of the various ion-channels leading to high influxes of calci-um, sodium and bicarbonate. The efflux of cholesterol during the process of capacitation alters the permeability of themembrane to the ions and generate areas which are prone to fusion and ve.siculation process during the acrosome reactioa. this review focuses mainly on effects of the ion and ion-channels, free radicals, and membrane fluidity changesduring the process of capacitation and acrosome reaction.

  1. Experimental determination of dielectric barrier discharge capacitance.

    Science.gov (United States)

    Pipa, A V; Hoder, T; Koskulics, J; Schmidt, M; Brandenburg, R

    2012-07-01

    The determination of electrical parameters (such as instantaneous power, transferred charge, and gas gap voltage) in dielectric barrier discharge (DBD) reactors relies on estimates of key capacitance values. In the classic large-scale sinusoidal-voltage driven DBD, also known as silent or ozonizer discharge, capacitance values can be determined from charge-voltage (Q-V) plot, also called Lissajous figure. For miniature laboratory reactors driven by fast pulsed voltage waveforms with sub-microsecond rise time, the capacitance of the dielectric barriers cannot be evaluated from a single Q-V plot because of the limited applicability of the classical theory. Theoretical determination can be problematic due to electrode edge effects, especially in the case of asymmetrical electrodes. The lack of reliable capacitance estimates leads to a "capacitance bottleneck" that obstructs the determination of other DBD electrical parameters in fast-pulsed reactors. It is suggested to obtain capacitance of dielectric barriers from a plot of the maximal charge versus maximal voltage amplitude (Q(max) - V(max) plot) in a manner analogous to the classical approach. The method is examined using measurements of current and voltage waveforms of a coaxial DBD reactor in argon at 100 mbar driven by square voltage pulses with a rise time of 20 ns and with different voltage amplitudes up to 10 kV. Additionally, the applicability of the method has been shown for the data reported in literature measured at 1 bar of nitrogen-oxygen gas mixtures and xenon. PMID:22852728

  2. The effect of surface transport on water desalination by porous electrodes undergoing capacitive charging

    OpenAIRE

    Shocron, Amit N.; Suss, Matthew E.

    2016-01-01

    Capacitive deionization (CDI) is a technology in which water is desalinated by ion electrosorption into the electric double layers (EDLs) of charging porous electrodes. In recent years significant advances have been made in modeling the charge and salt dynamics in a CDI cell, but the possible effect of surface transport within diffuse EDLs on these dynamics has not been investigated. We here present theory which includes surface transport in describing the dynamics of a charging CDI cell. Thr...

  3. Capacitance of Graphene Bilayer as a Which-Layer Probe

    OpenAIRE

    Young, Andrea F.; Levitov, Leonid S.

    2011-01-01

    The unique capabilities of capacitance measurements in bilayer graphene enable probing of layer-specific properties that are normally out of reach in transport measurements. Furthermore, capacitance measurements in the top-gate and penetration field geometries are sensitive to different physical quantities: the penetration field capacitance probes the two layers equally, whereas the top gate capacitance preferentially samples the near layer, resulting in the "near-layer capacitance enhancemen...

  4. 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

  5. Parking lots owned and maintained by the U.S. Fish and Wildlife Service

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — U.S. Fish and Wildlife Service parking lot inventory includes parking lots owned and maintained by the U.S. Fish and Wildlife Service on National Wildlife Refuges,...

  6. Quantum Fluctuation of Mesoscopic Capacitance Coupled Circuit in a Thermal Vacuum State

    Institute of Scientific and Technical Information of China (English)

    朱爱东; 张寿; 金哲; 赵永芳; 井孝功; 千正男; 苏文辉

    2003-01-01

    The quantum fluctuations of mesoscopic capacitance-coupled circuit in thermal vacuum state are investigated by using the theory of thermal field dynamics on the basis of quantization of the mesoscopic circuit. It is shown that under a definite temperature, the fluctuations of electric charges and currents change with temperature. The higher the temperature, the more quantum noise the coupled circuit exhibits.

  7. A New Capacitance Probe for Measuring the Local Moisture Content in Wet Porous Media

    Institute of Scientific and Technical Information of China (English)

    HanJitian; ShiMingheng; 等

    1997-01-01

    A new capacitance probe is developed for measuring local moisture content in wet porous media.The measurement principle,sensor structure of the probe,dynamic response characteristics and calibration procedure are discussed in detail.The experimental results show that the probe can be used to measure the local moisture content in wet porous media.

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

    DEFF Research Database (Denmark)

    Christiansen, Christian Holk; Lysgaard, Jens

    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....... Computational experiments show promising results....

  9. LOT SIZING WITH NON-ZERO SETUP TIMES FOR REWORK

    Institute of Scientific and Technical Information of China (English)

    Rasoul HAJI; Alireza HAJI; Mehdi SAJADIFAR; Saeed ZOLFAGHARI

    2008-01-01

    In this paper we consider a single machine multi-product lot scheduling problem in which defective items are produced in any production run of each product. In each cycle after the normal production of each product the machine is setup for the rework of the defectives of the same product and then the rework process starts. We assume that the setup time for the normal production process as well as the rework process is non-zero. Further we consider the waiting time cost of defectives for rework. This paper has two objectives. The first objective is to obtain the economic batch quantity (EBQ) for a single product. The second objective is to extend the result of the first objective to the multi-product case. Adopting the common cycle scheduling policy we obtain optimal batch sizes for each product such that the total cost of the system per unit time is minimized.

  10. Note : Vierges de pitié du Lot

    OpenAIRE

    Castan, Félix-Marcel

    2013-01-01

    À l’initiative du Secrétariat départemental des Objets mobiliers du Lot, durant l’été 80, dans le Grenier du Chapitre de la Cathédrale de Cahors, une belle exposition a rassemblé les résultats d’une enquête de Mil,) Monique Escat, Conservateur adjoint, sur les Vierges de Pitié qui ont commencé à apparaître en Quercy à la fin du xvie siècle. En tête du catalogue, un commentaire du Professeur Marcel Durliat, de l’Université de Toulouse Le Mirail, synthétise les conclusions actuelles du point de...

  11. 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.

  12. CLSP问题的周期调度方法及其PSO求解%Cyclfc approach for capacltnted lot scheduling problem and its PSO-based algorithm.

    Institute of Scientific and Technical Information of China (English)

    施灿涛; 王文鹏; 李铁克

    2011-01-01

    采用分解思想考虑多阶段CLSP问题,从多阶段生产系统抽象出单阶段生产环节,提出以周期方式对该生产环节进行生产批量调度.在对CLSP周期调度问题进行描述和界定的基础上,建立了相应的数学模型,讨论了周期调度方法中的周期上界以及周期长度与物料批量大小之间的关系等性质,采用基于三层编码的粒子群优化算法进行问题求解.源于冷轧生产实际的计算实例表明周期方法能够大大降低问题的规模且所得设备调整费用比人工方法减少约16%.%By considering multi-stage capacitated lot scheduling problem with a thought of decomposition and abstracting several single stages from a multi-stage manufacture system,this paper proposes a cyclic approach for the capacitated lot-scheduling problem on each abstracted stage.The corresponding mathematical model is built based on the problem description and statement, and some properties of the cyclic approach, such ns upper bound for each cycle and the relationship between cycle length and lot sizes, are discovered. A PSO-based algorithm is employed with three-dimensional solution presentation. By computational tests with a real case from a cool rolling plant,it can be proved that the cyclic approach lends to a dramatic reduction of problem space and makes the setup costs degrade 16%.

  13. Analytical development and optimization of a graphene-solution interface capacitance model.

    Science.gov (United States)

    Karimi, Hediyeh; Rahmani, Rasoul; Mashayekhi, Reza; Ranjbari, Leyla; Shirdel, Amir H; Haghighian, Niloofar; Movahedi, Parisa; Hadiyan, Moein; Ismail, Razali

    2014-01-01

    Graphene, which as a new carbon material shows great potential for a range of applications because of its exceptional electronic and mechanical properties, becomes a matter of attention in these years. The use of graphene in nanoscale devices plays an important role in achieving more accurate and faster devices. Although there are lots of experimental studies in this area, there is a lack of analytical models. Quantum capacitance as one of the important properties of field effect transistors (FETs) is in our focus. The quantum capacitance of electrolyte-gated transistors (EGFETs) along with a relevant equivalent circuit is suggested in terms of Fermi velocity, carrier density, and fundamental physical quantities. The analytical model is compared with the experimental data and the mean absolute percentage error (MAPE) is calculated to be 11.82. In order to decrease the error, a new function of E composed of α and β parameters is suggested. In another attempt, the ant colony optimization (ACO) algorithm is implemented for optimization and development of an analytical model to obtain a more accurate capacitance model. To further confirm this viewpoint, based on the given results, the accuracy of the optimized model is more than 97% which is in an acceptable range of accuracy. PMID:24991496

  14. Analytical development and optimization of a graphene–solution interface capacitance model

    Directory of Open Access Journals (Sweden)

    Hediyeh Karimi

    2014-05-01

    Full Text Available Graphene, which as a new carbon material shows great potential for a range of applications because of its exceptional electronic and mechanical properties, becomes a matter of attention in these years. The use of graphene in nanoscale devices plays an important role in achieving more accurate and faster devices. Although there are lots of experimental studies in this area, there is a lack of analytical models. Quantum capacitance as one of the important properties of field effect transistors (FETs is in our focus. The quantum capacitance of electrolyte-gated transistors (EGFETs along with a relevant equivalent circuit is suggested in terms of Fermi velocity, carrier density, and fundamental physical quantities. The analytical model is compared with the experimental data and the mean absolute percentage error (MAPE is calculated to be 11.82. In order to decrease the error, a new function of E composed of α and β parameters is suggested. In another attempt, the ant colony optimization (ACO algorithm is implemented for optimization and development of an analytical model to obtain a more accurate capacitance model. To further confirm this viewpoint, based on the given results, the accuracy of the optimized model is more than 97% which is in an acceptable range of accuracy.

  15. 7 CFR 27.12 - Classification request for each lot of cotton.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Classification request for each lot of cotton. 27.12... CONTAINER REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Classification Requests § 27.12 Classification request for each lot of cotton. For each lot or mark of cotton of which...

  16. Integrated control and health monitoring capacitive displacement sensor development task. Orbit transfer rocket engine technology program

    Science.gov (United States)

    Collamore, Frank N.

    1989-01-01

    The development of a miniature multifunction turbomachinery shaft displacement sensor using state-of-the-art non-contract capacitive sensing technology is described. Axial displacement, radial displacement, and speed are sensed using a single probe within the envelope normally required for a single function. A survey of displacement sensing technology is summarized including inductive, capacitive, optical and ultrasonic techniques. The design and operation of an experimental triple function sensor is described. Test results are included showing calibration tests and simultaneous dynamic testing of multiple functions. Recommendations for design changes are made to improve low temperature performance, reliability, and for design of a flight type signal conditioning unit.

  17. Capacitance measurement of magnetic specific heat

    Science.gov (United States)

    King, A. R.; Belanger, D. P.; Nordblad, P.; Jaccarino, V.

    1984-03-01

    A new technique-low frequency capacitance (C) measurement-has been used to study the critical behavior of both isotropic and anisotropic antiferromagnets. We find that dC/dT is accurately proportional to the known magnetic specific heat Cm of FeF2. This indicates that both dɛ/dT and dl/dT scale with Cm. For cubic KNiF3, the critical exponent (Cm=At-α) has been found to be α=-0.151±.004 and A/A'=1.56±0.03. The experiments measured the capacitance of disk-shaped samples with a three-terminal capacitance technique. A ratio transformer bridge was employed, yielding a resolution in ΔC/C of about 10-8. The quality of the results is comparable to the best obtainable from conventional Cm and birefringence measurements.

  18. 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.

  19. Signal processing electronics for a capacitive microsensor

    Science.gov (United States)

    Amendola, Gilles; Lu, Guo N.

    2000-04-01

    An interface circuit in a 0.8-micrometers CMOS process for the on- chip integration of a capacitive micro-sensor used as a microphone is presented. In order to circumvent 1/f noise contributions and to improve the signal/noise ratio, a synchronous modulation-demodulation technique has been applied. For the implementation of this technique, we have studied and designed several functional block, such as modulator with signal conversion, low-noise amplifier, demodulator, etc. To deal with problems related to dispersion of intrinsic capacitance of the sensor, a feedback compensating solution is suggested. The designed circuit has a sensibility of 1200 V/pF, with a minimum detectable capacitance variation of 2 10-6 pF.

  20. A high performance, variable capacitance accelerometer

    Science.gov (United States)

    Wilner, L. Bruce

    1988-12-01

    A variable capacitance acceleration sensor is described. Manufactured using silicon microfabrication techniques, the sensor uses a midplane, flat plate suspension, gas damping, and overrange stops. The sensor is assembled from three silicon wafers, using anodic bonds to inlays of borosilicate glass. Typical sensor properties are 7-pF active capacitance, 3-pF tare capacitance, a response of 0.05 pF/G, a resonance frequency of 3.4 kHz, and damping 0.7 critical. It is concluded that this sensor, with appropriate electronics, forms an accelerometer with an order-of-magnitude greater sensitivity-bandwidth product than a comparable piezoresistive acclerometer, and with extraordinary shock resistance.

  1. 7 CFR 201.30b - Lot number or other lot identification of vegetable seed in containers of more than 1 pound.

    Science.gov (United States)

    2010-01-01

    ... seed in containers of more than 1 pound. 201.30b Section 201.30b Agriculture Regulations of the... than 1 pound. The lot number or other lot identification of vegetable seed in containers of more than 1 pound shall be shown on the label and shall be the same as that used in the records pertaining to...

  2. A Novel Quadrature Signal Estimation Method for a Planar Capacitive Incremental Displacement Sensor

    Science.gov (United States)

    Yu, Jian-Ping; Wang, Wen; Li, Xin; Zhou, Zhao-Zhong

    2016-06-01

    This paper presents a novel phase-shift arctangent (PSA) interpolation method to improve the measurement accuracy of a planar capacitive incremental displacement sensor. Signals of planar capacitive micro-sensors acquire waveform errors, including sensitivity differences and phase-shift errors, because of static errors and dynamic disturbances. In the proposed PSA scheme, such errors are removed completely by loading a particular arctangent function. Moreover, measuring efficiency of the proposed planar capacitive sensors is improved by combining coarse measurement and fine estimation. Experiments show unanimous results to model-based fitting. When electrode length is four times the gap distance, applying the PSA interpolation method decreases waveform errors from more than 4 % to 1.72 %.

  3. A novel quasi-digital detection method of micro differential capacitance in micro-accelerometers

    Science.gov (United States)

    Song, Xing; Fang, Jiancheng; Yi, Ranran; Sheng, Wei

    2008-10-01

    This paper proposed a novel method of sensing the weak differential capacitance change of Micro-Electro-Mechanical Systems (MEMS) accelerometer with sandwich structure. The detection circuit mainly consisted of frequency selective networks, Phase Locked Loop (PLL), logical gate and low-pass filter. The two elemental capacitances of differential capacitance respectively harmonic oscillated in two parameter symmetry resonance units. Beating wave represented when the two output signals with different frequency had passed the logical gate and low-pass filter in turn. The frequency of beating wave was proportional to the sensing differential capacitance. One of the most important aspects of using circuit resonance elements with MEMS technology was the elimination of analog voltage amplitude measurement used in conventional MEMS accelerometers. On the other hand, this method overcame the disadvantages of conventional mechanical resonance accelerometers, with frequency output and high Signal Noise Ratio (SNR), such as poor dynamic response, temperature drift, complex structure and large power dissipation. According to the numerical simulation results, the circuit resonance detector with PLL can reach high capacitance resolution: 10-16 F.

  4. 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 sensor...... with a discrete components electronics circuit for signal conditioning. Using an AC bridge electronics circuit a resolution of 8 mV/mbar is achieved. The large signal is obtained due to a novel membrane structure utilizing closely packed hexagonal elements. The sensor is fabricated in a process based...

  5. Development of a 3D capacitive gyroscope with reduced parasitic capacitance

    Science.gov (United States)

    Walther, A.; Desloges, B.; Lejuste, C.; Coster, B.; Audebert, P.; Willemin, J.

    2013-02-01

    We present the development of a technological platform dedicated to 3D capacitive inertial sensors. The proof of concept will be made on a 3D gyroscope. The mobile structure is made within a 30 µm thick Si top layer of a SOI substrate, while poly-Si deposited on top of a sacrificial PSG layer serves as suspended top electrodes and connection wires. This technology enables us to maintain low parasitic capacitance, which is of paramount significance for capacitive detection. After packaging and association with an analogue electronic board, functionality of the sensor is demonstrated.

  6. Development of a 3D capacitive gyroscope with reduced parasitic capacitance

    International Nuclear Information System (INIS)

    We present the development of a technological platform dedicated to 3D capacitive inertial sensors. The proof of concept will be made on a 3D gyroscope. The mobile structure is made within a 30 µm thick Si top layer of a SOI substrate, while poly-Si deposited on top of a sacrificial PSG layer serves as suspended top electrodes and connection wires. This technology enables us to maintain low parasitic capacitance, which is of paramount significance for capacitive detection. After packaging and association with an analogue electronic board, functionality of the sensor is demonstrated. (paper)

  7. Pedestrian and traffic safety in parking lots at SNL/NM : audit background report.

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, Paul Ernest

    2009-03-01

    This report supplements audit 2008-E-0009, conducted by the ES&H, Quality, Safeguards & Security Audits Department, 12870, during fall and winter of FY 2008. The study evaluates slips, trips and falls, the leading cause of reportable injuries at Sandia. In 2007, almost half of over 100 of such incidents occurred in parking lots. During the course of the audit, over 5000 observations were collected in 10 parking lots across SNL/NM. Based on benchmarks and trends of pedestrian behavior, the report proposes pedestrian-friendly features and attributes to improve pedestrian safety in parking lots. Less safe pedestrian behavior is associated with older parking lots lacking pedestrian-friendly features and attributes, like those for buildings 823, 887 and 811. Conversely, safer pedestrian behavior is associated with newer parking lots that have designated walkways, intra-lot walkways and sidewalks. Observations also revealed that motorists are in widespread noncompliance with parking lot speed limits and stop signs and markers.

  8. Extending cluster lot quality assurance sampling designs for surveillance programs.

    Science.gov (United States)

    Hund, Lauren; Pagano, Marcello

    2014-07-20

    Lot quality assurance sampling (LQAS) has a long history of applications in industrial quality control. LQAS is frequently used for rapid surveillance in global health settings, with areas classified as poor or acceptable performance on the basis of the binary classification of an indicator. Historically, LQAS surveys have relied on simple random samples from the population; however, implementing two-stage cluster designs for surveillance sampling is often more cost-effective than simple random sampling. By applying survey sampling results to the binary classification procedure, we develop a simple and flexible nonparametric procedure to incorporate clustering effects into the LQAS sample design to appropriately inflate the sample size, accommodating finite numbers of clusters in the population when relevant. We use this framework to then discuss principled selection of survey design parameters in longitudinal surveillance programs. We apply this framework to design surveys to detect rises in malnutrition prevalence in nutrition surveillance programs in Kenya and South Sudan, accounting for clustering within villages. By combining historical information with data from previous surveys, we design surveys to detect spikes in the childhood malnutrition rate. PMID:24633656

  9. 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.

  10. Analysis of mutual capacitance and inductance of printed circuit

    OpenAIRE

    Ivanov, V. G.

    2014-01-01

    The article analyzes the mutual capacitance and inductance of printed circuit and introduces an evaluation technique for conductor-to-conductor capacitance under electrical connections tracing, the technique based on a multi-layer channel model.

  11. Observation of Quantum Capacitance of individual single walled carbon nanotubes

    OpenAIRE

    Dai, Junfeng; Li, Jun; Zeng, Hualing; Cui, Xiaodong

    2008-01-01

    We report a measurement on quantum capacitance of individual semiconducting and small band gap SWNTs. The observed quantum capacitance is remarkably smaller than that originating from density of states and it implies a strong electron correlation in SWNTs.

  12. Capacitive facial movement detection for human-computer interaction to click by frowning and lifting eyebrows: assistive technology.

    Science.gov (United States)

    Rantanen, Ville; Niemenlehto, Pekka-Henrik; Verho, Jarmo; Lekkala, Jukka

    2010-01-01

    A capacitive facial movement detection method designed for human-computer interaction is presented. Some point-and-click interfaces use facial electromyography for clicking. The presented method provides a contactless alternative. Electrodes with no galvanic coupling to the face are used to form electric fields. Changes in the electric fields due to facial movements are detected by measuring capacitances between the electrodes. A prototype device for measuring a capacitance signal affected by frowning and lifting eyebrows was constructed. A commercial integrated circuit for capacitive touch sensors is used in the measurement. The applied movement detection algorithm uses an adaptive approach to provide operation capability in noisy and dynamic environments. Experimentation with 10 test subjects proved that, under controlled circumstances, the movements are detected with good efficiency, but characterizing the movements into frowns and eyebrow lifts is more problematic. Integration with a two-dimensional (2D) pointing solution and further experiments are still required. PMID:20016948

  13. Fabrication of capacitively-shunted superconducting qubits

    Science.gov (United States)

    Yoder, Jonilyn L.; Gudmundsen, Theodore J.; Bolkhovsky, Vladimir; Welander, Paul B.; Gustavsson, Simon; Hover, David; Kerman, Andrew J.; Sears, Adam P.; Oliver, William D.

    2014-03-01

    Improvements in superconducting qubit coherence times and reproducibility have been demonstrated using capacitive shunting. In this study, we present methods for the preparation of both capacitively-shunted charge qubits (transmons) and capacitively-shunted flux qubits. Hybrid fabrication techniques were employed to combine high-quality-factor aluminum capacitive shunts with shadow-evaporated Josephson junctions, and the Josephson junctions were prepared using suspended-bridge germanium masks. We also will describe process testing results that were acquired to assess wafer-to-wafer reproducibility of our fabrication protocols. This research was funded in part by the Office of the Director of National Intelligence (ODNI), Intelligence Advanced Research Projects Activity (IARPA); and by the Assistant Secretary of Defense for Research and Engineering under Air Force Contract number FA8721-05-C-0002. All statements of fact, opinion or conclusions contained herein are those of the authors and should not be construed as representing the official views or policies of IARPA, the ODNI, or the U.S. Government.

  14. Teaching of Inductive and Capacitive Reactance.

    Science.gov (United States)

    MacInnes, I.; Jeffrey, W. S.

    1983-01-01

    Discusses how understanding mechanical systems and their graphic representation can be of value when teaching inductive and capacitive reactance, in particular, the response of inductors and capacitors to an alternating potential difference. Suggests that mechanical systems be taught, not just before introducing reactance but earlier in the…

  15. 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

  16. Capacitive Proximity Sensors With Additional Driven Shields

    Science.gov (United States)

    Mcconnell, Robert L.

    1993-01-01

    Improved capacitive proximity sensors constructed by incorporating one or more additional driven shield(s). Sensitivity and range of sensor altered by adjusting driving signal(s) applied to shield(s). Includes sensing electrode and driven isolating shield that correspond to sensing electrode and driven shield.

  17. Phase-Discriminating Capacitive Sensor System

    Science.gov (United States)

    Vranish, John M.; Rahim, Wadi

    1993-01-01

    Crosstalk eliminated by maintaining voltages on all electrodes at same amplitude, phase, and frequency. Each output feedback-derived control voltage, change of which indicates proximity-induced change in capacitance of associated sensing electrode. Sensors placed close together, enabling imaging of sort. Images and/or output voltages used to guide robots in proximity to various objects.

  18. Capacitive Displacement Sensor With Frequency Readout

    Science.gov (United States)

    Fritsch, Klaus

    1989-01-01

    Simple displacement-measuring circuit senses capacitance between two parallel conducting plates and produces output signal, with frequency proportional to distance between plates. Principle of circuit provides advantages over other methods because of frequency-encoded output and high linearity. Used to measure displacements.

  19. 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.

  20. Site Specific Evaluation of Multisensor Capacitance Probes

    Science.gov (United States)

    Multisensor capacitance probes (MCPs) are widely used for measuring soil water content (SWC) at the field scale. Although manufacturers supply a generic MCP calibration, many researchers recognize that MCPs should be calibrated for specific field conditions. MCPs measurements are typically associa...

  1. Capacitors and Resistance-Capacitance Networks.

    Science.gov (United States)

    Balabanian, Norman; Root, Augustin A.

    This programed textbook was developed under a contract with the United States Office of Education as Number 5 in a series of materials for use in an electrical engineering sequence. It is divided into three parts--(1) capacitors, (2) voltage-current relationships, and (3) simple resistance-capacitance networks. (DH)

  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; all...

  3. [Experience in developing and using capacitive electrodes].

    Science.gov (United States)

    Grishanovich, A P; Iarmolinskiĭ, V I

    1984-01-01

    A capacitive-type electrode using titanium or tantalum oxide obtained through anodizing is described. Incorporated in the electrode is a source for a buffer amplifier. A shielding cap is used as an indifferent electrode. High performance allows using the electrodes for ECG, EEG, and other signal recording in clinical practice and researches. PMID:6708763

  4. Anisotropic magneto-capacitance in ferromagnetic-plate capacitors

    OpenAIRE

    Haigh, J. A.; Ciccarelli, C; Betz, A. C.; Irvine, A; Novák, V.; Jungwirth, T.; Wunderlich, J.

    2015-01-01

    The capacitance of a parallel plate capacitor can depend on applied magnetic field. Previous studies have identified capacitance changes induced via classical Lorentz force or spin-dependent Zeeman effects. Here we measure a magnetization direction dependent capacitance in parallel-plate capacitors where one plate is a ferromagnetic semiconductor, gallium manganese arsenide. This anisotropic magneto-capacitance is due to the anisotropy in the density of states dependent on the magnetization t...

  5. Negative Quantum Capacitance of Carbon Nanotube Field-Effect Transistors

    OpenAIRE

    Latessa, L.; Pecchia, A.; Di Carlo, A.; P. Lugli

    2004-01-01

    Atomistic density functional theory (DFT) calculations of the capacitance between a metallic cylindric gate and a carbon nanotube (CNT) are reported. Results stressing the predominant effect of quantum capacitance in limiting or even enhancing screening properties of the CNT are shown. Other contributions to the quantum capacitance beyond the electronic density of state (DOS) are pointed out. Negative values of the quantum capacitance are obtained for low-density systems, which correspondingl...

  6. 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.

  7. Electric field theory and the fallacy of void capacitance

    OpenAIRE

    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 of equipotential. With this essential characteristics the validity of void capacitance is examined

  8. Egg and a lot of science: an interdisciplinary experiment

    Directory of Open Access Journals (Sweden)

    M. C. Gayer

    2014-08-01

    Full Text Available Egg and a lot of science: an interdisciplinary experimentGayer, M.C.1,2;Rodrigues, D.T.1,2; Escoto, D.F.1; Denardin, E.L.G.2, Roehrs, R.1,21Interdisciplinary Research Group on Teaching Practice, Graduate Program in Biochemistry, Unipampa, RS, Brazil2Laboratory of Physicochemical Studies and Natural Products, Post Graduate Program in Biochemistry, Unipampa, RS, BrazilIntroduction: How to tell if an egg is rotten? How to calculate the volume of an egg? Because the rotten egg float? Why has this characteristic rotten egg smell? Because the gray-green color is formed on the surface of the cooked egg yolk? These issues are commonplace and unnoticed in day-to-day. Our grandmothers know how to tell if an egg is rotten or not, you just put the egg in a glass of water. If it is rotten floating, sinking is good. But why this happens? That they do not know answer. With only one egg chemical reactions work, macromolecules (proteins, density, membranes and conservation of matter. Hydrogen sulphide is responsible for the aroma of a freshly cooked egg. This gas as they break down the molecules of albumin, a protein present in the egg is formed. The color comes from a sulfide precipitation, this time with the Fe2+ ion contained in the yolk (Fe2+ + S2  FeS. The use of simple and easy to perform experiments, correlating various knowledge proves a very useful tool in science education. Objectives: Develop multidisciplinary learning contents through the problem. Materials and methods: The teacher provides students with a boiled egg, salt, a syringe and a cup, a plate and water. The teacher lays the aforementioned issues for students and allows them to exchange information with each other, seeking answers through experimentation. Results and discussion: Students engaged with the activity and interaction of groups in order to solve the proposed problem. Still, through trial and error have sought in various ways to find the answers. This tool takes the student to

  9. Measurement of vehicle-load using capacitance and acceleration transducers

    International Nuclear Information System (INIS)

    Over-loading is a common problem in some developing countries. Currently, large and fixed measurement systems are used to measure the load of vehicles travelling on highways. This paper presents an on-vehicle measuring device, which is based on measurement of change in capacitance due to variation in distance between electrodes mounted on vehicles. The on-vehicle leaf springs are used as a key part of the weighing transducer. Acceleration transducers are used to measure the vehicle's forward and the vertical accelerations. A feature of this on-vehicle measuring device is that it can provide both static and dynamic load measurements. The drivers can check the load in the cab, and the highway inspectors can check the load at any time and any place through radio communication, thus identifying over-loaded vehicles

  10. MEMS capacitive force sensors for cellular and flight biomechanics.

    Science.gov (United States)

    Sun, Yu; Nelson, Bradley J

    2007-03-01

    Microelectromechanical systems (MEMS) are playing increasingly important roles in facilitating biological studies. They are capable of providing not only qualitative but also quantitative information on the cellular, sub-cellular and organism levels, which is instrumental to understanding the fundamental elements of biological systems. MEMS force sensors with their high bandwidth and high sensitivity combined with their small size, in particular, have found a role in this domain, because of the importance of quantifying forces and their effect on the function and morphology of many biological structures. This paper describes our research in the development of MEMS capacitive force sensors that have already demonstrated their effectiveness in the areas of cell mechanics and Drosophila flight dynamics studies. PMID:18458415

  11. MEMS capacitive force sensors for cellular and flight biomechanics

    Energy Technology Data Exchange (ETDEWEB)

    Sun Yu [Advanced Micro and Nanosystems Laboratory, University of Toronto, 5 King' s College Road, Toronto M5S 3G8 (Canada); Nelson, Bradley J [Institute of Robotics and Intelligent Systems, Swiss Federal Institute of Technology (ETH-Zuerich), Zurich (Switzerland)

    2007-03-01

    Microelectromechanical systems (MEMS) are playing increasingly important roles in facilitating biological studies. They are capable of providing not only qualitative but also quantitative information on the cellular, sub-cellular and organism levels, which is instrumental to understanding the fundamental elements of biological systems. MEMS force sensors with their high bandwidth and high sensitivity combined with their small size, in particular, have found a role in this domain, because of the importance of quantifying forces and their effect on the function and morphology of many biological structures. This paper describes our research in the development of MEMS capacitive force sensors that have already demonstrated their effectiveness in the areas of cell mechanics and Drosophila flight dynamics studies. (review article)

  12. MEMS capacitive force sensors for cellular and flight biomechanics

    International Nuclear Information System (INIS)

    Microelectromechanical systems (MEMS) are playing increasingly important roles in facilitating biological studies. They are capable of providing not only qualitative but also quantitative information on the cellular, sub-cellular and organism levels, which is instrumental to understanding the fundamental elements of biological systems. MEMS force sensors with their high bandwidth and high sensitivity combined with their small size, in particular, have found a role in this domain, because of the importance of quantifying forces and their effect on the function and morphology of many biological structures. This paper describes our research in the development of MEMS capacitive force sensors that have already demonstrated their effectiveness in the areas of cell mechanics and Drosophila flight dynamics studies. (review article)

  13. Simultaneous Optimal Placement of Distributed Generation and Electric Vehicle Parking Lots Based on Probabilistic EV Model

    Directory of Open Access Journals (Sweden)

    M.H. Amini

    2013-12-01

    Full Text Available High penetration of distributed generations and the increasing demand for using electric vehicles provide a lot of issues for the utilities. If these two effective elements of the future power system are used in an unscheduled manner, it may lead to the loss increment in distribution networks, dramatically. In this paper, the simultaneous allocation of distributed generations (DGs and electric vehicles (EVs parking lots has been studied in a radial distribution network. A distribution network which is upgrading and equipped with DGs is considered and these resources' optimal placement is achieved in interaction with the EV parking lots in order to minimize the power distribution network loss. The proposed method considers not only the loss minimization but also the reliability of the parking lot from the investor's point of view. The output of this model is the daily electricity demand of parking lot. The proposed method includes two levels. At the first level of the proposed algorithm, the parking lot investor makes decision and selects three candidate buses for each parking based on three main criteria. After making decision by the parking lot investor, the candidate buses are introduced to the distribution network operator. At the second stage, the distribution network operator allocates the DGs and EV parking lots based on the candidate buses of investor in order to achieve the minimum loss of the distribution network. Finally, the effectiveness of the proposed method is evaluated by allocating of DGs and EV parking lots simultaneously on the standard distribution test system.

  14. Encapsulation of Capacitive Micromachined Ultrasonic Transducers Using Viscoelastic Polymer.

    Science.gov (United States)

    Lin, Der-Song; Zhuang, Xuefeng; Wong, Serena H; Kupnik, Mario; Khuri-Yakub, Butrus Thomas

    2010-12-01

    The packaging of a medical imaging or therapeutic ultrasound transducer should provide protective insulation while maintaining high performance. For a capacitive micromachined ultrasonic transducer (CMUT), an ideal encapsulation coating would therefore require a limited and predictable change on the static operation point and the dynamic performance, while insulating the high dc and dc actuation voltages from the environment. To fulfill these requirements, viscoelastic materials, such as polydimethylsiloxane (PDMS), were investigated for an encapsulation material. In addition, PDMS, with a glass-transition temperature below room temperature, provides a low Young's modulus that preserves the static behavior; at higher frequencies for ultrasonic operation, this material becomes stiffer and acoustically matches to water. In this paper, we demonstrate the modeling and implementation of the viscoelastic polymer as the encapsulation material. We introduce a finite element model (FEM) that addresses viscoelasticity. This enables us to correctly calculate both the static operation point and the dynamic behavior of the CMUT. CMUTs designed for medical imaging and therapeutic ultrasound were fabricated and encapsulated. Static and dynamic measurements were used to verify the FEM and show excellent agreement. This paper will help in the design process for optimizing the static and the dynamic behavior of viscoelastic-polymer-coated CMUTs. PMID:21170294

  15. Layer resolved capacitive probing of graphene bilayers

    Science.gov (United States)

    Zibrov, Alexander; Parmentier, François; Li, Jia; Wang, Lei; Hunt, Benjamin; Dean, Cory; Hone, James; Taniguchi, Takashi; Watanabe, Kenji; Young, Andrea

    Compared to single layer graphene, graphene bilayers have an additional ``which-layer'' degree of freedom that can be controlled by an external electric field in a dual-gated device geometry. We describe capacitance measurements capable of directly probing this degree of freedom. By performing top gate, bottom gate, and penetration field capacitance measurements, we directly extract layer polarization of both Bernal and twisted bilayers. We will present measurements of hBN encapsulated bilayers at both zero and high magnetic field, focusing on the physics of the highly degenerate zero-energy Landau level in the high magnetic field limit where spin, valley, and layer degeneracy are all lifted by electronic interactions.

  16. A simple and reproducible capacitive electrode.

    Science.gov (United States)

    Spinelli, Enrique; Guerrero, Federico; García, Pablo; Haberman, Marcelo

    2016-03-01

    Capacitive Electrodes (CE) allow the acquisition of biopotentials through a dielectric layer, without the use of electrolytes, just by placing them on skin or clothing, but demands front-ends with ultra-high input impedances. This must be achieved while providing a path for bias currents, calling for ultra-high value resistors and special components and construction techniques. A simple CE that uses bootstrap techniques to avoid ultra-high value components and special materials is proposed. When electrodes are placed on the skin; that is, with coupling capacitances CS of around 100 pF, they present a noise level of 3.3 µVRMS in a 0.5-100 Hz bandwidth, which is appropriate for electrocardiography (ECG) measurements. Construction details of the CE and the complete circuit, including a fast recovery feature, are presented. PMID:26792172

  17. Development of a capacitive bioimpedance measurement system

    OpenAIRE

    Gómez Abad, Daniel

    2009-01-01

    Bioelectrical impedance spectroscopy (BIS) is a well-established and non-invasive method to determine and monitor body composition. Commercially available bioelectrical impedance systems use coated hydrogel-aluminium electrodes, where the hydrogel acts as an adhesive and as an electrolytic medium. The gel/adhesive is physiologically inert over short periods. However, when used over longer periods, hydrogel-aluminium electrodes present limitations, which capacitive electrodes ma...

  18. Performance relations in Capacitive Deionization systems

    OpenAIRE

    Limpt, van, C.

    2010-01-01

    Capacitive Deionization (CDI) is a relatively new deionization technology based on the temporary storage of ions on an electrically charged surface. By directing a flow between two oppositely charged surfaces, negatively charged ions will adsorb onto the positively charged surface, and positively charged ions will adsorb onto the negatively charged surface. To optimize CDI design for various applications, performance relations in CDI systems have to be understood. CDI performance is determine...

  19. Ultra-High-Frequency Capacitive Displacement Sensor

    Science.gov (United States)

    Vanzandt, Thomas R.; Kenny, Thomas W.; Kaiser, William J.

    1994-01-01

    Improved class of compact, high-resolution capacitive displacement sensors operates at excitation frequency of 915 MHz and measures about 7.5 by 4 by 2 centimeters. Contains commercially available 915-MHz oscillator and transmission-line resonator. Resonator contains stripline inductor in addition to variable capacitor. Ultrahigh excitation frequency offers advantages of resolution and frequency response. Not deleteriously affected by mechanical overdriving, or contact between electrodes.

  20. Capacitive Sensors And Targets Would Measure Alignments

    Science.gov (United States)

    Jenstrom, Del T.

    1994-01-01

    Multiple capacitive sensors and active targets used to measure distance between, and relative orientation of, two objects. Sensed target signals processed and used by control systems to align objects to be joined. Shapes, sizes, and layouts of sensors and targets optimized for specific application. Particular layout of targets and sensors enables determination of relative position and orientation of two objects in all six degrees of freedom.

  1. The fringe capacitance formula of microstructures

    International Nuclear Information System (INIS)

    This paper presents a fringe capacitance formula of microstructures. The formula is derived by curve fitting on ANSYS simulation results. Compared with the ANSYS and experimental results, the deviation is within ±2%. The application to determine the pull-in voltage of an electrostatic micro-beam is demonstrated, which agrees very well with the experimental data. The formula presented is very accurate, yields explicit physical meanings and is applicable to common dimension ranges for MEMS devices. (paper)

  2. Effect of astaxanthin on human sperm capacitation.

    Science.gov (United States)

    Donà, Gabriella; Kožuh, Ivana; Brunati, Anna Maria; Andrisani, Alessandra; Ambrosini, Guido; Bonanni, Guglielmo; Ragazzi, Eugenio; Armanini, Decio; Clari, Giulio; Bordin, Luciana

    2013-06-01

    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. PMID:23736766

  3. 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.

  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. Multi-Channel Capacitive Sensor Arrays.

    Science.gov (United States)

    Wang, Bingnan; Long, Jiang; Teo, Koon Hoo

    2016-01-01

    In this paper, multi-channel capacitive sensor arrays based on microstrip band-stop filters are studied. The sensor arrays can be used to detect the proximity of objects at different positions and directions. Each capacitive sensing structure in the array is connected to an inductive element to form resonance at different frequencies. The resonances are designed to be isolated in the frequency spectrum, such that the change in one channel does not affect resonances at other channels. The inductive element associated with each capacitive sensor can be surface-mounted inductors, integrated microstrip inductors or metamaterial-inspired structures. We show that by using metamaterial split-ring structures coupled to a microstrip line, the quality factor of each resonance can be greatly improved compared to conventional surface-mounted or microstrip meander inductors. With such a microstrip-coupled split-ring design, more sensing elements can be integrated in the same frequency spectrum, and the sensitivity can be greatly improved. PMID:26821023

  6. Low leakage ZrO2 based capacitors for sub 20 nm dynamic random access memory technology nodes

    Science.gov (United States)

    Pešić, Milan; Knebel, Steve; Geyer, Maximilian; Schmelzer, Sebastian; Böttger, Ulrich; Kolomiiets, Nadiia; Afanas'ev, Valeri V.; Cho, Kyuho; Jung, Changhwa; Chang, Jaewan; Lim, Hanjin; Mikolajick, Thomas; Schroeder, Uwe

    2016-02-01

    During dynamic random access memory (DRAM) capacitor scaling, a lot of effort was put searching for new material stacks to overcome the scaling limitations of the current material stack, such as leakage and sufficient capacitance. In this study, very promising results for a SrTiO3 based capacitor with a record low capacitance equivalent thickness value of 0.2 nm at target leakage current are presented. Due to the material properties of SrTiO3 films (high vacancy concentration and low band gap), which are leading to an increased leakage current, a physical thickness of at least 8 nm is required at target leakage specifications. However, this physical thickness would not fit into an 18 nm DRAM structure. Therefore, two different new approaches to develop a new ZrO2 based DRAM capacitor stack by changing the inter-layer material from Al2O3 to SrO and the exchange of the top electrode material from TiN to Pt are presented. A combination of these two approaches leads to a capacitance equivalent thickness value of 0.47 nm. Most importantly, the physical thickness of target specifications. Detailed evaluation of the leakage current characteristics leads to a capacitor model which allows the prediction of the electrical behavior with thickness scaling.

  7. Distributed Capacitive Sensor for Sample Mass Measurement

    Science.gov (United States)

    Toda, Risaku; McKinney, Colin; Jackson, Shannon P.; Mojarradi, Mohammad; Manohara, Harish; Trebi-Ollennu, Ashitey

    2011-01-01

    Previous robotic sample return missions lacked in situ sample verification/ quantity measurement instruments. Therefore, the outcome of the mission remained unclear until spacecraft return. In situ sample verification systems such as this Distributed Capacitive (DisC) sensor would enable an unmanned spacecraft system to re-attempt the sample acquisition procedures until the capture of desired sample quantity is positively confirmed, thereby maximizing the prospect for scientific reward. The DisC device contains a 10-cm-diameter pressure-sensitive elastic membrane placed at the bottom of a sample canister. The membrane deforms under the weight of accumulating planetary sample. The membrane is positioned in close proximity to an opposing rigid substrate with a narrow gap. The deformation of the membrane makes the gap narrower, resulting in increased capacitance between the two parallel plates (elastic membrane and rigid substrate). C-V conversion circuits on a nearby PCB (printed circuit board) provide capacitance readout via LVDS (low-voltage differential signaling) interface. The capacitance method was chosen over other potential approaches such as the piezoelectric method because of its inherent temperature stability advantage. A reference capacitor and temperature sensor are embedded in the system to compensate for temperature effects. The pressure-sensitive membranes are aluminum 6061, stainless steel (SUS) 403, and metal-coated polyimide plates. The thicknesses of these membranes range from 250 to 500 m. The rigid substrate is made with a 1- to 2-mm-thick wafer of one of the following materials depending on the application requirements glass, silicon, polyimide, PCB substrate. The glass substrate is fabricated by a microelectromechanical systems (MEMS) fabrication approach. Several concentric electrode patterns are printed on the substrate. The initial gap between the two plates, 100 m, is defined by a silicon spacer ring that is anodically bonded to the glass

  8. Artificial Neural Network Based Rotor Capacitive Reactance Control for Energy Efficient Wound Rotor Induction Motor

    Directory of Open Access Journals (Sweden)

    K. Siva Kumar

    2012-01-01

    Full Text Available Problem statement: The Rotor reactance control by inclusion of external capacitance in the rotor circuit has been in recent research for improving the performances of Wound Rotor Induction Motor (WRIM. The rotor capacitive reactance is adjusted such that for any desired load torque the efficiency of the WRIM is maximized. The rotor external capacitance can be controlled using a dynamic capacitor in which the duty ratio is varied for emulating the capacitance value. This study presents a novel technique for tracking maximum efficiency point in the entire operating range of WRIM using Artificial Neural Network (ANN. The data for ANN training were obtained on a three phase WRIM with dynamic capacitor control and rotor short circuit at different speed and load torque values. Approach: A novel neural network model based on the back-propagation algorithm has been developed and trained in determining the maximum efficiency of the motor with no prior knowledge of the machine parameters. The input variables to the ANN are stator current (Is, Speed (N and Torque (Tm and the output variable is the duty ratio (D. Results: The target is pre-set and the accuracy of the ANN model is measured using Mean Square Error (MSE and R2 parameters. The result of R2 value of the proposed ANN model is found to be 0.99980. Conclusion: The optimal duty ratio and corresponding optimal rotor capacitance for improving the performances of the motor are predicted for low, medium and full loads by using proposed ANN model.

  9. A Novel Method for Proximity Detection of Moving Targets Using a Large-Scale Planar Capacitive Sensor System.

    Science.gov (United States)

    Ye, Yong; Deng, Jiahao; Shen, Sanmin; Hou, Zhuo; Liu, Yuting

    2016-01-01

    A novel method for proximity detection of moving targets (with high dielectric constants) using a large-scale (the size of each sensor is 31 cm × 19 cm) planar capacitive sensor system (PCSS) is proposed. The capacitive variation with distance is derived, and a pair of electrodes in a planar capacitive sensor unit (PCSU) with a spiral shape is found to have better performance on sensitivity distribution homogeneity and dynamic range than three other shapes (comb shape, rectangular shape, and circular shape). A driving excitation circuit with a Clapp oscillator is proposed, and a capacitance measuring circuit with sensitivity of 0.21 V p - p / pF is designed. The results of static experiments and dynamic experiments demonstrate that the voltage curves of static experiments are similar to those of dynamic experiments; therefore, the static data can be used to simulate the dynamic curves. The dynamic range of proximity detection for three projectiles is up to 60 cm, and the results of the following static experiments show that the PCSU with four neighboring units has the highest sensitivity (the sensitivities of other units are at least 4% lower); when the attack angle decreases, the intensity of sensor signal increases. This proposed method leads to the design of a feasible moving target detector with simple structure and low cost, which can be applied in the interception system. PMID:27196905

  10. A Novel Method for Proximity Detection of Moving Targets Using a Large-Scale Planar Capacitive Sensor System

    Directory of Open Access Journals (Sweden)

    Yong Ye

    2016-05-01

    Full Text Available A novel method for proximity detection of moving targets (with high dielectric constants using a large-scale (the size of each sensor is 31 cm × 19 cm planar capacitive sensor system (PCSS is proposed. The capacitive variation with distance is derived, and a pair of electrodes in a planar capacitive sensor unit (PCSU with a spiral shape is found to have better performance on sensitivity distribution homogeneity and dynamic range than three other shapes (comb shape, rectangular shape, and circular shape. A driving excitation circuit with a Clapp oscillator is proposed, and a capacitance measuring circuit with sensitivity of 0.21 V p − p / pF is designed. The results of static experiments and dynamic experiments demonstrate that the voltage curves of static experiments are similar to those of dynamic experiments; therefore, the static data can be used to simulate the dynamic curves. The dynamic range of proximity detection for three projectiles is up to 60 cm, and the results of the following static experiments show that the PCSU with four neighboring units has the highest sensitivity (the sensitivities of other units are at least 4% lower; when the attack angle decreases, the intensity of sensor signal increases. This proposed method leads to the design of a feasible moving target detector with simple structure and low cost, which can be applied in the interception system.

  11. A branch-and-cut algorithm for the capacitated profitable tour problem

    DEFF Research Database (Denmark)

    Jepsen, Mads Kehlet; Petersen, Bjørn; Spoorendonk, Simon;

    2014-01-01

    This paper considers the Capacitated Profitable Tour Problem (CPTP) which is a special case of the Elementary Shortest Path Problem with Resource Constraints (ESPPRC). The CPTP belongs to the group of problems known as traveling salesman problems with profits. In CPTP each customer is associated...... with a profit and a demand and the objective is to find a capacitated tour (rooted in a depot node) that minimizes the total travel distance minus the profit of the visited customers. The CPTP can be recognized as the sub-problem in many column generation applications, where it is traditionally solved...... instances with 800 nodes to optimality where the dynamic programming algorithms cannot solve instances with more than 200 nodes. Moreover dynamic programming and branch-and-cut complement each other well, giving us hope for solving more general problems through hybrid approaches. The paper is intended to...

  12. MODEL JOINT ECONOMIC LOT SIZE PADA KASUS PEMASOK-PEMBELI DENGAN PERMINTAAN PROBABILISTIK

    Directory of Open Access Journals (Sweden)

    Wakhid Ahmad Jauhari

    2009-01-01

    Full Text Available In this paper we consider single vendor single buyer integrated inventory model with probabilistic demand and equal delivery lot size. The model contributes to the current literature by relaxing the deterministic demand assumption which has been used for almost all integrated inventory models. The objective is to minimize expected total costs incurred by the vendor and the buyer. We develop effective iterative procedures for finding the optimal solution. Numerical examples are used to illustrate the benefit of integration. A sensitivity analysis is performed to explore the effect of key parameters on delivery lot size, safety factor, production lot size factor and the expected total cost. The results of the numerical examples indicate that our models can achieve a significant amount of savings. Finally, we compare the results of our proposed model with a simulation model. Abstract in Bahasa Indonesia: Pada penelitian ini akan dikembangkan model gabungan pemasok-pembeli dengan permintaan probabilistik dan ukuran pengiriman sama. Pada model setiap lot pemesanan akan dikirim dalam beberapa lot pengiriman dan pemasok akan memproduksi barang dalam ukuran batch produksi yang merupakan kelipatan integer dari lot pengiriman. Dikembangkan pula suatu algoritma untuk menyelesaikan model matematis yang telah dibuat. Selain itu, pengaruh perubahan parameter terhadap perilaku model diteliti dengan analisis sensitivitas terhadap beberapa parameter kunci, seperti ukuran lot, stok pengaman dan total biaya persediaan. Pada penelitian ini juga dibuat model simulasi untuk melihat performansi model matematis pada kondisi nyata. Kata kunci: model gabungan, permintaan probabilistik, lot pengiriman, supply chain

  13. Statistical assessment of DNA extraction reagent lot variability in real-time quantitative PCR

    Science.gov (United States)

    Bushon, R.N.; Kephart, C.M.; Koltun, G.F.; Francy, D.S.; Schaefer, F. W., III; Lindquist, H.D. Alan

    2010-01-01

    Aims: The aim of this study was to evaluate the variability in lots of a DNA extraction kit using real-time PCR assays for Bacillus anthracis, Francisella tularensis and Vibrio cholerae. Methods and Results: Replicate aliquots of three bacteria were processed in duplicate with three different lots of a commercial DNA extraction kit. This experiment was repeated in triplicate. Results showed that cycle threshold values were statistically different among the different lots. Conclusions: Differences in DNA extraction reagent lots were found to be a significant source of variability for qPCR results. Steps should be taken to ensure the quality and consistency of reagents. Minimally, we propose that standard curves should be constructed for each new lot of extraction reagents, so that lot-to-lot variation is accounted for in data interpretation. Significance and Impact of the Study: This study highlights the importance of evaluating variability in DNA extraction procedures, especially when different reagent lots are used. Consideration of this variability in data interpretation should be an integral part of studies investigating environmental samples with unknown concentrations of organisms. ?? 2010 The Society for Applied Microbiology.

  14. 7 CFR 56.37 - Lot marking of officially identified shell eggs.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Lot marking of officially identified shell eggs. 56.37... (CONTINUED) VOLUNTARY GRADING OF SHELL EGGS Grading of Shell Eggs Identifying and Marking Products § 56.37 Lot marking of officially identified shell eggs. Shell eggs identified with the grademarks shown...

  15. 7 CFR 800.85 - Inspection of grain in combined lots.

    Science.gov (United States)

    2010-01-01

    ... for grain in a combined lot shall, subject to the provisions of paragraphs (e) through (g) of this... shall be determined in accordance with the instructions. (e) Infested grain. If the grain in a combined... 7 Agriculture 7 2010-01-01 2010-01-01 false Inspection of grain in combined lots. 800.85...

  16. Excitation capacitance required for self excited single phase induction generator using three phase machine

    International Nuclear Information System (INIS)

    The minimum and maximum excitation capacitance required for a self excited single phase induction generator using a three phase machine has been determined by an eigenvalue and eigenvalue sensitivity approach. It is observed that the required minimum capacitance reduces with the increase in load. Traditionally, the minimum and maximum capacitances required for a self excited induction generator (SEIG) were solved by a high order non-linear polynomial equation based on a per phase equivalent circuit model. The advantage of this proposed method is its simplicity since the complicated solution procedure of the high order polynomial is avoided. The generator consists of a three phase star connected induction machine with three capacitors connected in series and parallel with a single phase load. The developed dynamic model of the SEIG is based on the stationary reference frame d-q axes theory, and the equations of the excitation capacitors are described by a three phase abc model assuming a constant speed prime mover. The capacitance values obtained by the proposed method have been compared with those obtained by the conventional method and verified experimentally to confirm the validity and the accuracy of the proposed method

  17. Capacitive Deionization using Biomass-based Microporous Salt-Templated Heteroatom-Doped Carbons.

    Science.gov (United States)

    Porada, Slawomir; Schipper, Florian; Aslan, Mesut; Antonietti, Markus; Presser, Volker; Fellinger, Tim-Patrick

    2015-06-01

    Invited for this month's cover are the groups of Tim-Patrick Fellinger (MPI Potsdam) and Volker Presser (INM Saarbrücken and Saarland University). The image shows the dynamic process of ion electrosorption: anions are attracted and cations repelled from electrically charged electrodes based on carbons with heteroatoms. This process of capacitive deionization is particularly attractive for facile low-energy water treatment applications. PMID:26039519

  18. DC Voltage Control Strategy for CHB-STATCOM during Capacitive-Inductive Load Transition

    Directory of Open Access Journals (Sweden)

    Bo Zhao

    2012-11-01

    Full Text Available Fluctuation of DC capacitor voltage of CHC-STATCOM(Cascaded H-Bridge Converter Based STATCOM during capacitive-inductive load transition affects the dynamic response of the equipment and, with combination of other factors like of the switching devices, can degrade the stability of the equipment. This paper illustrates the cause ofthe voltage fluctuation and proposes a novel and practical control strategy to suppress it. A simulation was conducted to testify its effectiveness.

  19. DC Voltage Control Strategy for CHB-STATCOM during Capacitive-Inductive Load Transition

    OpenAIRE

    Bo Zhao; Yong Wang; Weiming Zhao

    2012-01-01

    Fluctuation of DC capacitor voltage of CHC-STATCOM(Cascaded H-Bridge Converter Based STATCOM) during capacitive-inductive load transition affects the dynamic response of the equipment and, with combination of other factors like of the switching devices, can degrade the stability of the equipment. This paper illustrates the cause ofthe voltage fluctuation and proposes a novel and practical control strategy to suppress it. A simulation was conducted to testify its effectiveness.

  20. Capacitance-type blade-tip clearance measurement system using a dual amplifier with ramp/dc inputs and integration

    Science.gov (United States)

    Sarma, Garimella R.; Barranger, John P.

    1992-01-01

    The analysis and prototype results of a dual-amplifier circuit for measuring blade-tip clearance in turbine engines are presented. The capacitance between the blade tip and mounted capacitance electrode within a guard ring of a probe forms one of the feedback elements of an operational amplifier (op amp). The differential equation governing the circuit taking into consideration the nonideal features of the op amp was formulated and solved for two types of inputs (ramp and dc) that are of interest for the application. Under certain time-dependent constraints, it is shown that (1) with a ramp input the circuit has an output voltage proportional to the static tip clearance capacitance, and (2) with a dc input, the output is proportional to the derivative of the clearance capacitance, and subsequent integration recovers the dynamic capacitance. The technique accommodates long cable lengths and environmentally induced changes in cable and probe parameters. System implementation for both static and dynamic measurements having the same high sensitivity is also presented.

  1. Peculiarities of capacitive characteristics of dielectrics with high permittivity

    International Nuclear Information System (INIS)

    The rapid pace of development of microelectronics towards nano miniaturization dictates the inevitable introduction of dielectrics with high permittivity (high-k dielectrics), as alternative materials for replacing conventionally used silicon as insulating oxide. Therefore, studying these materials in terms of their characteristics, especially in terms of reliability, is of great importance for proper design and manufacture of devices that incorporate dielectrics with high permittivity. In this paper, different properties and behavior of a group of samples that contain dielectrics with high permittivity are investigated, by analyzing the characteristics of capacitive curves, which are product of this powerful technique for characterization, reflecting a great number of elements for the overall behavior of the material, especially their behavior in working conditions. Samples investigated here belong to the group of tantalum based metal oxides, whereas here we examine layers of pure Ta2O5, but also layers of Hf and Ti doped tantalum pentoxide, i.e. Ta2O5: Hf and Ta2O5: Ti. All samples are considered as ultrathin oxide layers with thicknesses less than 15 nm, and they are obtained by thermal oxidation or by radio frequency sputtering on p-type silicon substrate. From capacitive characteristics we have obtained the specific parameters that determine the properties of materials (capacitance in accumulation, equivalent oxide thickness of dielectric layer, the thickness and time evolution of the interfacial SiO2 layer, characteristic values of flat band and threshold voltage, density of oxide charges present in the layer, as well as interface and border states), and properties that show the behavior of the materials in working conditions (such as the process of creation of additional charges when voltage is applied, or charge trapping dynamics). Particular attention has been paid to determining the impact of the type of top electrode (the gate), on the overall

  2. Image reconstruction for field-focusing capacitance imaging

    International Nuclear Information System (INIS)

    For online monitoring of multi-phase flows of non-conductive materials, a field-focusing capacitance imaging system has been developed. With a field focusing capacitance sensor, a tomographic image based on capacitance measurements is used directly to map the material distribution. However, it is difficult to achieve a required accuracy for measurement of void fraction from the capacitance image, because of the soft-field effect of the capacitance sensor. In this paper, the forward and inverse problems with a field-focusing capacitance sensor are described. Simulation and experimental results show that deconvolution-based algorithms can reduce the blurring artefact and can reconstruct an image close to the original distribution

  3. 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.

  4. CMOS MEMS capacitive absolute pressure sensor

    International Nuclear Information System (INIS)

    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. (paper)

  5. Probing Quantum Capacitance in a 3D Topological Insulator

    OpenAIRE

    Kozlov, D. A.; Bauer, Dominik; Ziegler, Johannes; Fischer, Ralf, 1965-; Savchenko, M. L.; Kvon, Z.D.; Mikhailov, N. N.; Dvoretsky, S. A.; Weiss, Dieter

    2016-01-01

    We measure the quantum capacitance and probe thus directly the electronic density of states of the high mobility, Dirac type of two-dimensional electron system, which forms on the surface of strained HgTe. Here we show that observed magneto-capacitance oscillations probe, in contrast to magnetotransport, primarily the top surface. Capacitance measurements constitute thus a powerful tool to probe only one topological surface and to reconstruct its Landau level spectrum for different positions ...

  6. Accurate sizing of supercapacitors storage system considering its capacitance variation.

    OpenAIRE

    Trieste, Sony; Bourguet, Salvy; Olivier, Jean-Christophe; Loron, Luc; Le Claire, Jean-Claude

    2011-01-01

    This paper highlights the energy errors made for the design of supercapacitors used as a main energy source. First of all, the paper presents the two definitions of capacitance of a capacitance-voltage dependent material. The number of supercapacitors is important for the application purchasing cost. That is why the paper introduces an analytical model and an electrical model along with an identification method for the capacitance variation. This variation is presented and compared to the man...

  7. 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.

  8. Capacitive position measurement for high-precision space inertial sensor

    Institute of Scientific and Technical Information of China (English)

    Yan-zheng BAI; Ze-bing ZHOU; Hai-bo TU; Shu-chao WU; Lin CAI; LI LIU; Jun LUO

    2009-01-01

    Low noise position measurement is fundamental for space inertial sensors, and at present the capacitive position sensor is widely employed for space inertial sensors. The design for the possible suppression of the front-end electric noises for a capacitive sensor is presented. A prototype capacitive sensor with 2x 10-6pF/Hzi/2 at frequency above 0.04 Hz is achieved and further improvements are discussed.

  9. DEVELOPMENT OF ADAPTED CAPACITANCE MANOMETER FOR  THERMOSPHERIC APPLICATIONS

    OpenAIRE

    Orr, Cameron Scott

    2016-01-01

    An adapted capacitance manometer is a sensor composed of one fixed plate and one movable plate that is able to make accurate pressure measurements in a low pressure environment. Using detection circuitry, a change in capacitance between the two plates can be measured and correlated to a differential pressure. First, a high sensitivity manometer is produced that exhibits a measurable change in capacitance when experiencing a pressure differential in a low pressure space environment. Second,...

  10. Static and Motional Feedthrough Capacitance of Flexural Microresonator

    OpenAIRE

    Wen-Teng Chang

    2011-01-01

    The present paper evaluates the static and motional feedthrough capacitance of a silicon carbide-based flexural-mode microelectromechanical system resonator. The static feedthrough capacitance was measured by a network analyzer under atmospheric pressure. The motional feedthrough was obtained by introducing various values into the modeling circuit in order to fit the Bode plots measured under reduced pressure. The static feedthrough capacitance was 0.02 pF, whereas the motional feedthrough ca...

  11. Capacitive tool standoff sensor for dismantlement tasks

    International Nuclear Information System (INIS)

    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

  12. 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.

  13. 3-D capacitance density imaging system

    Science.gov (United States)

    Fasching, G.E.

    1988-03-18

    A three-dimensional capacitance density imaging of a gasified bed or the like in a containment vessel is achieved using a plurality of electrodes provided circumferentially about the bed in levels and along the bed in channels. The electrodes are individually and selectively excited electrically at each level to produce a plurality of current flux field patterns generated in the bed at each level. The current flux field patterns are suitably sensed and a density pattern of the bed at each level determined. By combining the determined density patterns at each level, a three-dimensional density image of the bed is achieved. 7 figs.

  14. Combinatorial Algorithms for Capacitated Network Design

    OpenAIRE

    Hajiaghayi, MohammadTaghi; Khandekar, Rohit; Kortsarz, Guy; Nutov, Zeev

    2011-01-01

    We focus on designing combinatorial algorithms for the Capacitated Network Design problem (Cap-SNDP). The Cap-SNDP is the problem of satisfying connectivity requirements when edges have costs and hard capacities. We begin by showing that the Group Steiner tree problem (GST) is a special case of Cap-SNDP even when there is connectivity requirement between only one source-sink pair. This implies the first poly-logarithmic lower bound for the Cap-SNDP. We next provide combinatorial algorithms fo...

  15. Quantum capacitance of graphene in contact with metal

    International Nuclear Information System (INIS)

    We report a versatile computation method to quantitatively determine the quantum capacitance of graphene when it is in contact with metal. Our results bridge the longstanding gap between the theoretically predicted and experimentally measured quantum capacitance of graphene. Contrary to popular assumptions, the presence of charged impurities or structural distortions of graphene are not the only sources of the asymmetric capacitance with respect to the polarity of the bias potential and the higher-than-expected capacitance at the Dirac point. They also originate from the field-induced electronic interactions between graphene and metal. We also provide an improved model representation of a metal–graphene junction

  16. Quantum capacitance of graphene in contact with metal

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Jin Hyun, E-mail: jin.chang@mail.utoronto.ca; Dawson, Francis [The Edward S. Rogers Sr. Department of Electrical and Computer Engineering, University of Toronto, 10 King' s College Road, Toronto, Ontario M5S 3G4 (Canada); Huzayyin, Ahmed [The Edward S. Rogers Sr. Department of Electrical and Computer Engineering, University of Toronto, 10 King' s College Road, Toronto, Ontario M5S 3G4 (Canada); Electrical Power and Machines Department, Cairo University, Giza 12316 (Egypt); Lian, Keryn [Department of Materials Science and Engineering, University of Toronto, 184 College Street, Toronto M5S 1A1 (Canada)

    2015-11-09

    We report a versatile computation method to quantitatively determine the quantum capacitance of graphene when it is in contact with metal. Our results bridge the longstanding gap between the theoretically predicted and experimentally measured quantum capacitance of graphene. Contrary to popular assumptions, the presence of charged impurities or structural distortions of graphene are not the only sources of the asymmetric capacitance with respect to the polarity of the bias potential and the higher-than-expected capacitance at the Dirac point. They also originate from the field-induced electronic interactions between graphene and metal. We also provide an improved model representation of a metal–graphene junction.

  17. Calibration of capacitive hydrostatic leveling sensors of NSRL

    International Nuclear Information System (INIS)

    The principle of capacitive hydrostatic leveling sensors was presented. Simulations of sensors with two kinds of materials (metal and distilled water) as target electrode in the situations of calibration and work were carried out by Ansoft Maxwell software. Different values of capacitances in different situations were compared and analyzed. Then some experiments were done with independently developed prototype of capacitive hydrostatic leveling sensors to verify the above simulations. In the situations of calibration and work, the same property (conductivity and dielectric constant) material as target electrode should be chosen for capacitive hydrostatic leveling sensors. Otherwise, there is an error of sensors after calibration, and the main factor is conductivity. (authors)

  18. Variable-capacitance tachometer eliminates troublesome magnetic fields

    Science.gov (United States)

    1966-01-01

    Dual variable-capacitance tachometer measures angular speed and sense of rotation without magnetic components. Thus it eliminates magnetic flux interference with associated instrumentation in an electromechanical system.

  19. A comprehensive mathematical model for hybrid flexible flowshop lot streaming problem

    Directory of Open Access Journals (Sweden)

    Fantahun M. Defersha

    2011-04-01

    Full Text Available Lot streaming is a technique of splitting production lots into smaller sublots in a multi-stage manufacturing systems so that operations of a given lot can be overlapped. This technique can reduce manufacturing makespan and is an effective tool for time-based manufacturing strategy. Several research articles appeared in literature to solve this problem and most of these studies are limited to pure flowshop environments where there is only a single machine in each stage. On the other hand, because of the applicability of hybrid flowshops in different manufacturing settings, the scheduling of these types of shops is also extensively studied by several authors. However, the issue of lot streaming in hybrid flowshop environment is not well studied. In this paper, we aim to initiate research in bridging the gap between the research efforts in flowshop lot streaming and hybrid flowshop scheduling. We present a comprehensive mathematical model for scheduling flexible hybrid flowshop with lot streaming. Numerical example demonstrated that lot streaming can result in larger makespan reduction in hybrid flowshop where there is a limited research than in pure flowshop where research is abundant.

  20. Towards understanding the structure and capacitance of electrical double layer in ionic liquids

    International Nuclear Information System (INIS)

    In order to understand basic principles of the double layer formation in room temperature ionic liquids, we have performed Molecular Dynamic simulations for a simplified system: dense assembly of charged Lennard-Jones spheres between charged walls. For simplicity, in this first investigation we have considered the cations and anions of the same size. We have calculated the corresponding values of the double layer capacitance as a function of the electrode potential and compared the results with existing theories. We have found that the capacitance curve does not follow the U-shape of the Gouy-Chapman theory, but has a bell-shape in agreement with the mean-field theory that takes into account the effect of limited maximum packing of ions. The wings of capacitance decrease inversely proportional to the square root of the electrode potential, as prescribed by the mean-field theory and the charge conservation law at large electrode polarizations. We have found, however, that the mean-field theory does not quantitatively reproduce the simulation results at small electrode potentials, having detected their remarkable overscreening effects (ionic correlations). The plots for the distributions of ions near the electrode at different electrode charges show that for the considered system, unlike it is often assumed, the double layer is not one layer thick. The overscreening effects, dominating near the potential of zero charge (p.z.c.), are suppressed by the high electrode polarizations, following the onset of the so-called 'lattice saturation effect'. The maximum of the capacitance coincides with the p.z.c., but it is true only for this 'symmetric' system. If sizes of cations and anions are different the maximum will be shifted away from the p.z.c., and generally the shape of the capacitance curve could be more complicated

  1. Void fraction measurement with capacitance meter

    International Nuclear Information System (INIS)

    The void fraction in an air-water system has been measured using the capacitance meter. Various flow regimes including bubbly, slug, churn, annular and drop-annular flow have been investigated. The superficial air and water velocity have been varied in the range of 0.145 less than or equal to j /SUB f/ less than or equal to 3.62 ft/sec and 0.183 less than or equal to j /SUB g/ less than or equal to 63.7 ft/sec respectively and the void fraction has been varied from 0.04 to 0.94. The capacitance meter is calibrated by both quick closing valve method and theoretical calculation based on drift-flux model. The sensitivity of void fraction measurement on sensor shape has been investigated with sensors of different width. Using the conventional theoretical curves of void fraction vs. relative susceptance, the results show that the sensor width has strong effect on void fraction measurement especially annular flow regime. The results also show that significant discrepancy exists between the theoretical curve and the experimental results. The reason for this discrepancy has been identified due to two dimensional edge effect of the circular sensor. A 2-D model has been developed taking into account of both sensor width and flow regime which gives good prediction of the experimental results

  2. 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.

  3. Proportional microvolume capacitive liquid level sensor array.

    Science.gov (United States)

    Seliskar, D; Waterbury, R; Kearney, R

    2005-01-01

    A sensor array has been developed for use with laboratory automation to permit closed-loop control of liquid levels in a multiwell microplate geometry. We extended a simple electrical model for non-contact capacitance-based fluid sensors to describe a fluid-level dependency. The new model shows that a charge-transfer based capacitance transducer, employing a liquid-specific calibration, can be used to obtain an output signal that varies linearly with the liquid level. The calibration also compensates for liquid-to-liquid conductivity and permittivity differences. A prototype 3×3 sensor array was built and tested using NaCl and ethanol solutions to simulate the range of conductivity and permittivity typical in biological and chemical research. Calibrated output signals were linear with liquid volume for all tested solutions (R2>0.92). Measurement error averaged 1.3 % (2.0 μl) with a standard deviation of 6.0% (9.0 μl). These results demonstrate the feasibility of developing a microvolume sensor array in essentially any M×N microplate geometry. PMID:17281955

  4. A capacitive electrode with fast recovery feature

    International Nuclear Information System (INIS)

    Capacitive electrodes (CEs) allow for acquiring biopotentials without galvanic contact, avoiding skin preparation and the use of electrolytic gel. The signal quality provided by present CEs is similar to that of standard wet electrodes, but they are more sensitive to electrostatic charge interference and motion artifacts, mainly when biopotentials are picked up through clothing and coupling capacitances are reduced to tens of picofarads. When artifacts are large enough to saturate the preamplifier, several seconds (up to tens) are needed to recover a proper baseline level, and during this period biopotential signals are irremediably lost. To reduce this problem, a CE that includes a fast-recovery (FR) circuit is proposed. It works directly on the coupling capacitor, recovering the amplifier from saturation while preserving ultra-high input impedance, as a CE requires. A prototype was built and tested acquiring ECG signals. Several experimental data are presented, which show that the proposed circuit significantly reduces record segment losses due to amplifier saturation when working in real environments. (paper)

  5. Capacitive Sensing of Intercalated H2O Molecules Using Graphene.

    Science.gov (United States)

    Olson, Eric J; Ma, Rui; Sun, Tao; Ebrish, Mona A; Haratipour, Nazila; Min, Kyoungmin; Aluru, Narayana R; Koester, Steven J

    2015-11-25

    Understanding the interactions of ambient molecules with graphene and adjacent dielectrics is of fundamental importance for a range of graphene-based devices, particularly sensors, where such interactions could influence the operation of the device. It is well-known that water can be trapped underneath graphene and its host substrate; however, the electrical effect of water beneath graphene and the dynamics of how the interfacial water changes with different ambient conditions has not been quantified. Here, using a metal-oxide-graphene variable-capacitor (varactor) structure, we show that graphene can be used to capacitively sense the intercalation of water between graphene and HfO2 and that this process is reversible on a fast time scale. Atomic force microscopy is used to confirm the intercalation and quantify the displacement of graphene as a function of humidity. Density functional theory simulations are used to quantify the displacement of graphene induced by intercalated water and also explain the observed Dirac point shifts as being due to the combined effect of water and oxygen on the carrier concentration in the graphene. Finally, molecular dynamics simulations indicate that a likely mechanism for the intercalation involves adsorption and lateral diffusion of water molecules beneath the graphene. PMID:26502269

  6. Lots of Physicists Are Nervous about the Speed of Light%Lots of Physicists Are Nervous about the Speed of Light

    Institute of Scientific and Technical Information of China (English)

    Eric Randall

    2011-01-01

    [1] Physicists spent their weekends walking back media hype over an experiment that at first glance seems to disprove Einstein's famed theory of relativity. They preached dispassionate skepticism, but behind all that careful cynicism, there seemed a lot of hand-wringing.

  7. The 'Thinking a Lot' Idiom of Distress and PTSD: An Examination of Their Relationship among Traumatized Cambodian Refugees Using the 'Thinking a Lot' Questionnaire

    NARCIS (Netherlands)

    D.E. Hinton; R. Reis; J. de Jong

    2015-01-01

    "Thinking a lot" (TAL)—also referred to as "thinking too much"—is a key complaint in many cultural contexts, and the current article profiles this idiom of distress among Cambodian refugees. The article also proposes a general model of how TAL generates various types of distress that then cause PTSD

  8. Experimental study of a variable-capacitance micromotor with electrostatic suspension

    International Nuclear Information System (INIS)

    A variable-capacitance micromotor where the rotor is supported electrostatically in five degrees of freedom was designed, fabricated and tested in order to study the behavior of this electrostatic motor. The micromachined device is based on a glass/silicon/glass stack bonding structure, fabricated by bulk micromachining and initially operated in atmospheric environment. The analytical torque model is obtained by calculating the capacitances between different stator electrodes and the rotor. Capacitance values in the order of 10−13 pF and torque values in the order of 10−10 N m have been calculated from the motor geometry and attainable drive voltage. A dynamic model of the motor is proposed by further estimating the air-film damping effect in an effort to explain the experimental rotation measurements. Experimental results of starting voltage, continuous operation, switching response and electric bearing of the micromotor are presented and discussed. Preliminary measurements indicate that a rotor rotating speed of 73.3 r min−1 can be achieved at a drive voltage of 28.3 V, equivalent to a theoretical motive torque of 517 pN m. Starting voltage results obtained from experimental measurement are in agreement with the developed dynamic model

  9. Interflow dynamics on a low relief forested hillslope: Lots of fill, little spill

    Science.gov (United States)

    Du, Enhao; Rhett Jackson, C.; Klaus, Julian; McDonnell, Jeffrey J.; Griffiths, Natalie A.; Williamson, Margaret F.; Greco, James L.; Bitew, Menberu

    2016-03-01

    We evaluated the occurrence of perching and interflow over and within a sandy clay loam argillic horizon within first-order, low-relief, forested catchments at the Savannah River Site (SRS) in the Upper Coastal Plain of South Carolina. We measured soil hydraulic properties, depths to the argillic layer, soil moisture, shallow groundwater behavior, interflow interception trench flows, and streamflow over a 4-year period to explore the nature and variability of soil hydraulic characteristics, the argillic "topography", and their influence on interflow generation. Perching occurred frequently within and above the restricting argillic horizons during our monitoring period, but interflow was infrequent due to microtopographic relief and associated depression storage on the argillic layer surface. High percolation rates through the argillic horizon, particularly through soil anomalies, also reduced the importance of interflow. Interflow generation was highly variable across eleven segments of a 121 m interception trench. Hillslopes were largely disconnected from stream behavior during storms. Hillslope processes were consistent with the fill-and-spill hypothesis and featured a sequence of distinct thresholds: vertical wetting front propagation to the argillic layer; saturation of the argillic followed by local perching; filling of argillic layer depressions; and finally connectivity of depressions leading to interflow generation. Analysis of trench flow data indicated a cumulative rainfall threshold of 60 mm to generate interflow, a value at the high end of the range of thresholds reported elsewhere.

  10. Efeito da redução do tamanho de lote e de programas de Melhoria Contínua no Estoque em Processo (WIP) e na Utilização: estudo utilizando uma abordagem híbrida System Dynamics - Factory Physics Effect of lot size reduction and Continuous Improvement on Work In Process and Utilization: study using a combined System Dynamics and Factory Physics approach

    OpenAIRE

    Moacir Godinho Filho; Reha Uzsoy

    2009-01-01

    O presente trabalho apresenta um modelo quantitativo que utiliza de forma híbrida as abordagens System Dynamics - SD (FORRESTER, 1962) e Factory Physics (HOPP; SPEARMAN, 2001) objetivando estudar o efeito conjunto de seis programas de Melhoria Contínua - CI (variabilidade na taxa de chegada, variabilidade do processo, qualidade, tempo até a falha, tempo de reparo e tempo de set up) e de redução de tamanhos de lote de produção nos níveis médios de Estoque em Processo (WIP) e Utilização em um a...

  11. LOTS as Fixed Point Sets: An Application of Tarski's Fixed Point Theorem (draft)

    OpenAIRE

    Papadopoulos, Kyriakos

    2013-01-01

    The class of LOTS (linearly ordered topological spaces) contains many important spaces, like the set of real numbers, the set of rational numbers and the ordinals. Such spaces have rich topological properties, which are not necessarily hereditary.

  12. 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...

  13. Improved circuit for measuring capacitive and inductive reactances

    Science.gov (United States)

    Dalins, I.; Mc Carty, V.

    1967-01-01

    Amplifier circuit measures very small changes of capacitive or inductive reactance, such as produced by a variable capacitance or a variable inductance displacement transducer. The circuit employs reactance-sensing oscillators in which field effect transistors serve as the active elements.

  14. 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...

  15. Polycrystalline VO2 film characterization by quantum capacitance measurement

    International Nuclear Information System (INIS)

    Capacitance measurement is performed using a home-built bridge on quasi two-dimensional vanadium dioxide films grown on silicon-dioxide/p-doped silicon substrates. Correlated effects appearing in the quantum capacitance are obtained as a function of temperature at low frequencies. The thermodynamic density of states reveals the opening band gap in the insulating monoclinic phase

  16. Traveling mirror compressor delay line with nonconstant capacitance

    OpenAIRE

    Bellan, P. M.

    1981-01-01

    The scaling relations for a traveling mirror magnetic compressor [P.M. Bellan, Phys. Rev. Lett. 43, 858 (1979)] having nonconstant capacitance are derived. Varying capacitance (rather than inductance) makes possible a lower impedance device, and hence, higher field levels or faster compression times.

  17. 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…

  18. ENVIROMENTAL IMPACT OF THE POLLUTANTS FROM FEED-LOT WASTEWATER ON THE UNDERGROUND WATER

    OpenAIRE

    Walter M. Glessi; Nélida N. Pose; Ester C. Zamuner

    2012-01-01

    In this study is investigated the impact of pollutant from wastewater generated for twelve feed-lot of the southeast of Buenos Aires Province, Argentina, to determine the significant aspects on the vulnerability of the underground water. The Conesa (2010) methodological impact assessment guide was used starting from twelve Environmental Impact Assessment and is analyzed the influence of the feed-lot on the underground water. The amount of livestock, type of soil, groundwater deep, kind of pra...

  19. Solving a combined cutting-stock and lot-sizing problem with a column generating procedure

    DEFF Research Database (Denmark)

    Nonås, Sigrid Lise; Thorstenson, Anders

    In Nonås and Thorstenson [A combined cutting stock and lot sizing problem. European Journal of Operational Research 120(2) (2000) 327-42] a combined cutting-stock and lot-sizing problem is outlined under static and deterministic conditions. In this paper we suggest a new column generating solutio...... indicate that the procedure works well also for the extended cutting-stock problem with only a setup cost for each pattern change....

  20. Permeability measurement and scan imaging to assess clogging of pervious concrete pavements in parking lots.

    Science.gov (United States)

    Kayhanian, Masoud; Anderson, Dane; Harvey, John T; Jones, David; Muhunthan, Balasingam

    2012-03-01

    This paper describes a study that used permeability measurement along with physical and hydrological characteristics of 20 pervious concrete pavements in parking lots throughout California. The permeability was measured at five locations: the main entrance, an area with no traffic, and three separate measurements within a parking space at each parking lot. Hydrological and physical site characteristics such as traffic flow, erosion, vegetation cover, sediments accumulation, maintenance practice, presence of cracking, rainfall, and temperature data were also collected for each parking lot. These data were used to perform detailed statistical analysis to determine factors influencing changes in permeability and hence assessing possible cause of clogging. In addition, seven representative core samples were obtained from four different parking lots with permeability ranging from very low to very high. Porosity profiles produced from CT scanning were used to assess the possible nature and extent of clogging. Results showed that there is a large variation in permeability within each parking lot and between different parking lots. In general, the age of the parking lot is the predominant factor influencing the permeability. Statistical analysis revealed that fine sediment (particles less than 38 μm) mass is also an important influencing factor. Other influencing factors with lower significance included number of days with a temperature greater than 30°C and the amount of vegetation next to the parking lot. The combined scanned image analysis and porosity profile of the cores showed that most clogging occurs near the surface of the pavement. While lower porosity generally appeared to be limited to the upper 25 mm, in some core samples evidence of lower porosity was found up to 100mm below the surface. PMID:22115516

  1. Changing the values of parameters on lot size reorder point model

    OpenAIRE

    Chang Hung-Chi

    2003-01-01

    The Just-In-Time (JIT) philosophy has received a great deal of attention. Several actions such as improving quality, reducing setup cost and shortening lead time have been recognized as effective ways to achieve the underlying goal of JIT. This paper considers the partial backorders, lot size reorder point inventory system with an imperfect production process. The objective is to simultaneously optimize the lot size, reorder point, process quality, setup cost and lead time, constrained on a s...

  2. Laboratory Assessment of Water Flow Simulator for Porous Parking Lots Reservoir and Soil Layers

    OpenAIRE

    Zul Fahmi Mohamed Jaafar; Meor Othman Hamzah; Fauziah Ahmad

    2011-01-01

    Porous parking lots were implemented to fill the scarcity and strengthen the sustainable development of impervious surfaces in Malaysia to reduce surface runoff. The new methodology proposed enable simulation of reservoir course at stipulated air voids despite details study on water levels and infiltration of porous parking lots system. A uniformly graded choker and reservoir stones functioned as reservoir structure for temporary storm water detention. A specially fabricated water flow simula...

  3. The Saccharomyces cerevisiae quinone oxidoreductase Lot6p: stability, inhibition and cooperativity

    OpenAIRE

    Megarity, Clare F.; Looi, Hong Keat; Timson, David J

    2014-01-01

    Lot6p (EC 1.5.1.39; Ylr011wp) is the sole quinone oxidoreductase in the budding yeast, Saccharomyces cerevisiae. Using hexahistidine tagged, recombinant Lot6p, we determined the steady-state enzyme kinetic parameters with both NADH and NADPH as electron donors; no cooperativity was observed with these substrates. The NQO1 inhibitor curcumin, the NQO2 inhibitor resveratrol, the bacterial nitroreductase inhibitor nicotinamide and the phosphate mimic vanadate all stabilise the enzyme towards the...

  4. A 16-{micro}A interface circuit for a capacitive flow sensor

    Energy Technology Data Exchange (ETDEWEB)

    Rodgers, B.; Yunus, M. [Integrated Sensor Solutions, San Jose, CA (United States); Goenawan, S. [Marvell Semiconductor, Sunnyvale, CA (United States); Kaneko, Yoshikazu; Yoshiike, Junichi [Nagano Keiki Co., Ltd. (Japan)

    1998-12-01

    A micropower interface circuit is described for fluidic flow measurement in commercial gas meters. The application-specific integrated circuit converts dynamic capacitive-flow sensor readings from 1 to 150 Hz into digital pulses suitable for reading by the host microcontroller. The signal path is first-order {Delta}{Sigma} modulation followed by a three-pole, one-zero infinite impulse response bandpass filter. Analog signal processing is fully differential switched capacitor, with amplifiers and dc current consuming blocks operating in weak inversion. Chip bias and oscillator frequency, and capacitive sensor offset and gain, are trimmed with on-chip EEPROM. Operating ranges are 2.5--3.6 V and from {minus}10 to 65 C, with active I{sub dd} of 16 {micro}A.

  5. Frequency limits for conducting graphene channel caused by quantum capacitance and kinetic inductance

    International Nuclear Information System (INIS)

    By analyzing the Boltzmann kinetic equation for mesosystems, it is shown that the quantum capacitance and the kinetic inductance, which are analogs of the electrostatic capacitance and the magnetic inductance, respectively, have to be taken into consideration while studying the dynamic conductivity of a graphene channel, despite their different physical nature. The account of the quantum conductance and the kinetic inductivity leads to the appearance of a maximum of the impedance. In the case where the graphene channel is an ideal Landauer resistor crossed by an electron without scattering, this maximum corresponds to the THz range (therefore, the e?ect does not worsen the frequency characteristics of graphene FETs operating in the GHz range). However, for massive graphene channels fabricated with the use of the CVD method, where the electron transport has the diffusive nature, this maximum corresponds to the kHz or MHz range depending on the carrier mobility and the channel length

  6. Capacitive microelectromechanical switches with dynamic soft-landing

    Energy Technology Data Exchange (ETDEWEB)

    Jain, Ankit; Alam, Muhammad Ashraful; Nair, Pradeep R.

    2015-10-13

    A microelectromechanical system (MEMS)-based electrical switch. The electrical switch includes a moveable electrode, a dielectric layer positioned adjacent the moveable electrode on a first side of the dielectric layer and spaced apart from the moveable electrode when the moveable electrode is in an inactivated position and in contact with the moveable electrode when the moveable electrode is in an activated position, and a substrate attached to the dielectric layer on a second side opposite to the first side, the moveable electrode is configured to brake prior to coming in contact with the dielectric layer when the moveable electrode is switched between the inactivated state and the activated state.

  7. Coal-tar-based parking lot sealcoat: An unrecognized source of PAH to settled house dust

    Science.gov (United States)

    Mahler, B.J.; Van Metre, P.C.; Wilson, J.T.; Musgrove, M.; Burbank, T.L.; Ennis, T.E.; Bashara, T.J.

    2010-01-01

    Despite much speculation, the principal factors controlling concentrations of polycyclic aromatic hydrocarbons (PAH) in settled house dust (SHD) have not yet been identified. In response to recent reports that dust from pavement with coaltar-based sealcoat contains extremely high concentrations of PAH, we measured PAH in SHD from 23 apartments and in dust from their associated parking lots, one-half of which had coal-tar-based sealcoat (CT). The median concentration of total PAH (T-PAH) in dust from CT parking lots (4760 ??g/g, n = 11) was 530 times higher than that from parking lots with other pavement surface types (asphalt-based sealcoat, unsealed asphalt, concrete [median 9.0 ??g/g, n = 12]). T-PAH in SHD from apartments with CT parking lots (median 129 ??g/g) was 25 times higher than that in SHD from apartments with parking lots with other pavement surface types (median 5.1 ??g/g). Presence or absence of CT on a parking lot explained 48% of the variance in log-transformed T-PAH in SHD. Urban land-use intensity near the residence also had a significant but weaker relation to T-PAH. No other variables tested, including carpeting, frequency of vacuuming, and indoor burning, were significant. ?? 2010 American Chemical Society.

  8. Discrete artificial bee colony algorithm for lot-streaming flowshop with total flowtime minimization

    Science.gov (United States)

    Sang, Hongyan; Gao, Liang; Pan, Quanke

    2012-09-01

    Unlike a traditional flowshop problem where a job is assumed to be indivisible, in the lot-streaming flowshop problem, a job is allowed to overlap its operations between successive machines by splitting it into a number of smaller sub-lots and moving the completed portion of the sub-lots to downstream machine. In this way, the production is accelerated. This paper presents a discrete artificial bee colony (DABC) algorithm for a lot-streaming flowshop scheduling problem with total flowtime criterion. Unlike the basic ABC algorithm, the proposed DABC algorithm represents a solution as a discrete job permutation. An efficient initialization scheme based on the extended Nawaz-Enscore-Ham heuristic is utilized to produce an initial population with a certain level of quality and diversity. Employed and onlooker bees generate new solutions in their neighborhood, whereas scout bees generate new solutions by performing insert operator and swap operator to the best solution found so far. Moreover, a simple but effective local search is embedded in the algorithm to enhance local exploitation capability. A comparative experiment is carried out with the existing discrete particle swarm optimization, hybrid genetic algorithm, threshold accepting, simulated annealing and ant colony optimization algorithms based on a total of 160 randomly generated instances. The experimental results show that the proposed DABC algorithm is quite effective for the lot-streaming flowshop with total flowtime criterion in terms of searching quality, robustness and effectiveness. This research provides the references to the optimization research on lot-streaming flowshop.

  9. Evaluation of coverage of enriched UF6 cylinder storage lots by existing criticality accident alarms

    International Nuclear Information System (INIS)

    The Portsmouth Gaseous Diffusion Plant (PORTS) is leased from the US Department of Energy (DOE) by the United States Enrichment Corporation (USEC), a government corporation formed in 1993. PORTS is in transition from regulation by DOE to regulation by the Nuclear Regulatory Commission (NRC). One regulation is 10 CFR Part 76.89, which requires that criticality alarm systems be provided for the site. PORTS originally installed criticality accident alarm systems in all building for which nuclear criticality accidents were credible. Currently, however, alarm systems are not installed in the enriched uranium hexafluoride (UF6) cylinder storage lots. This report analyzes and documents the extent to which enriched UF6 cylinder storage lots at PORTS are covered by criticality detectors and alarms currently installed in adjacent buildings. Monte Carlo calculations are performed on simplified models of the cylinder storage lots and adjacent buildings. The storage lots modelled are X-745B, X-745C, X745D, X-745E, and X-745F. The criticality detectors modelled are located in building X-343, the building X-344A/X-342A complex, and portions of building X-330 (see Figures 1 and 2). These criticality detectors are those located closest to the cylinder storage lots. Results of this analysis indicate that the existing criticality detectors currently installed at PORTS are largely ineffective in detecting neutron radiation from criticality accidents in most of the cylinder storage lots at PORTS, except sometimes along portions of their peripheries

  10. 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.

  11. Electrostatic capacitance and Faraday cage behavior of carbon nanotube forests

    International Nuclear Information System (INIS)

    Understanding of the electrostatic properties of carbon nanotube (CNT) forests is essential to enable their integration in microelectronic and micromechanical devices. In this study, we sought to understand how the hierarchical geometry and morphology of CNT forests determines their capacitance. First, we find that at small gaps, solid micropillars have greater capacitance, yet at larger gaps the capacitance of the CNT forests is greater. The surface area of the CNT forest accessible to the electrostatic field was extracted by analysis of the measured capacitance, and, by relating the capacitance to the average density of CNTs in the forest, we find that the penetration depth of the electrostatic field is on the order of several microns. Therefore, CNT forests can behave as a miniature Faraday cage. The unique electrostatic properties of CNT forests could therefore enable their use as long-range proximity sensors and as shielding elements for miniature electronic devices

  12. 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.

  13. Further capacitive imaging experiments using modified probes

    Science.gov (United States)

    Yin, Xiaokang; Li, Zhen; Yan, An; Li, Wei; Chen, Guoming; Hutchins, David A.

    2016-02-01

    In recent years, capacitive imaging (CI) is growing in popularity within the NDE communities, as it has the potential to test materials and structures for defects that are not easily tested by other techniques. In previous work, The CI technique has been successfully used on a various types of materials, including concrete, glass/carbon fibre composite, steel, etc. In such CI experiments, the probes are normally with symmetric or concentric electrodes etched onto PCBs. In addition to these conventional coplanar PCB probes, modified geometries can be made and they can lead to different applications. A brief overview of these modified probes, including high resolution surface imaging probe, combined CI/eddy current probe, and CI probe using an oscilloscope probe as the sensing electrode, is presented in this work. The potential applications brought by these probes are also discussed.

  14. A capacitive bioelectrode for recording electrophysiological signals

    International Nuclear Information System (INIS)

    In this paper we describe a gel-free sensor with on-board electrode design, which capacitive couples to the skin to detect the electrical activity in the body. The integrated sensor is manufactured on a standard printed circuit board within 2.2 cm diameter enclosure that can operate through fabric or other insulation. The electrode includes amplification (60db gain) and passive band pass filtering (0.5 to 100 Hz). Active shielding surrounding the sensor plate is used to reduce noise pickup. The input referred noise, measured over the electrode bandwidth is 4 μV rms at 0.2 mm sensor distance, and 16 μV rms at 1.2 mm distance trough two cotton cloths. The bioelectrodes were coupled to the scalp trough hair for EEG signals (with 80 db gain), and coupled to the chest through clothing for ECG signals. The recorded signals show well performance of the designed bielectrode. (Author)

  15. Phase discriminating capacitive array sensor system

    Science.gov (United States)

    Vranish, John M. (Inventor); Rahim, Wadi (Inventor)

    1993-01-01

    A phase discriminating capacitive sensor array system which provides multiple sensor elements which are maintained at a phase and amplitude based on a frequency reference provided by a single frequency stabilized oscillator. Sensor signals provided by the multiple sensor elements are controlled by multiple phase control units, which correspond to the multiple sensor elements, to adjust the sensor signals from the multiple sensor elements based on the frequency reference. The adjustment made to the sensor signals is indicated by output signals which indicate the proximity of the object. The output signals may also indicate the closing speed of the object based on the rate of change of the adjustment made, and the edges of the object based on a sudden decrease in the adjustment made.

  16. Capacitance multiplier and filter synthesizing network

    Science.gov (United States)

    Kline, A. J. (Inventor)

    1974-01-01

    A circuit using a differential amplifier multiplies the capacitance of a discrete interating capacitor by (r sub 1 + R sub 2)/R sub 2, where R sub 1 and R sub 2 are values of discrete resistor coupling an input signal e sub 1 of the amplifier inputs. The output e sub 0 of the amplifier is fed back and added to the signal coupled by the resistor R sub 2 to the amplifier through a resistor of value R sub 1. A discrete resistor R sub x may be connected in series for a lag filter, and a discrete resistor may be connected in series with the capacitor for a lead-lag filter. Voltage dividing resistors R sub a and R sub b may be included in the feedback circuit of the amplifier output e sub o to independently adjust the circuit gain e sub i/e sub o.

  17. 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.

  18. The hysteresis-free negative capacitance field effect transistors using non-linear poly capacitance

    Science.gov (United States)

    Fan, S.-T.; Yan, J.-Y.; Lai, D.-C.; Liu, C. W.

    2016-08-01

    A gate structure design for negative capacitance field effect transistors (NCFETs) is proposed. The hysteresis loop in current-voltage performances is eliminated by the nonlinear C-V dependence of polysilicon in the gate dielectrics. Design considerations and optimizations to achieve the low SS and hysteresis-free transfer were elaborated. The effects of gate-to-source/drain overlap, channel length scaling, interface trap states and temperature impact on SS are also investigated.

  19. Optimal and heuristic solutions for the single and multiple batch flow shop lot streaming problems with equal sublots

    OpenAIRE

    Kalir, Adar A.

    1999-01-01

    This research is concerned with the development of efficient solutions to various problems that arise in the flow-shop environments which utilize lot-streaming. Lot streaming is a commonly used process of splitting production lots into sublots and, then, of scheduling the sublots in an overlapping fashion on the machines, so as to expedite the progress of orders in production and to improve the overall performance of the production system. The different lot-streaming problems that arise i...

  20. A review of reconstruction techniques for capacitance tomography

    Science.gov (United States)

    Isaksen, Øyvind

    1996-03-01

    Capacitance tomography has been used to image several processes, such as liquid/gas pipe flow, oil/water/gas gravity separation, pneumatic conveying, fluidized beds and flame combustion. The nature of the capacitance sensors is such that reconstruction algorithms well developed for medical tomography are not applicable. The main problem is that the relationship between the measured quantity (capacitance) and the parameter of interest (distribution of the dielectric constant) is nonlinear. Furthermore, it is impossible to establish an explicit expression which relates the dielectric constant distribution to the measured capacitance. Also it should be pointed out that the number of measurements in capacitance tomography is small (typically less than 100) compared to medical tomography. For these reasons the first tested algorithm in capacitance tomography was based on the crude back projection algorithm. This algorithm has over the years been enhanced for use with a capacitance tomograph. In addition other techniques, such as various iterative methods, algorithms based on artificial neural networks and `look-up' tables have been developed and tested. This paper outlines the working principles for the different techniques and presents the main results.

  1. Hydraulic Resistance and Capacitance in the Soil—Plant System

    Institute of Scientific and Technical Information of China (English)

    SHAOMING-AN; L.P.SIMMONDS

    1991-01-01

    In this paper,the hydraulic resistances and capacitances were evaluated.based on the development of non-linear model of water flow in the soil-plant system and the simulating experiment work.The results show that the mean hydraulic resistance in the soil-plant system is 6.79×109 MPa·S·m-3;the mean hydraulic capacitance in the system is 5.2×10-7m3·MPa-1.In the components of hydraulic capacitance in the system,the capacitance in soil (81.8×10-6m3·MPa-1)is the biggest and its variability with soil water potential is extremely strong,the capacitance in plant (5.3×10-7m3·MPa-1) is much smaller than that in soil,and the capacitance in shoots (15.5×10-7m3·MPa-1) is bigger than that in roots (8.4×10-7m3·MPa-1).An interesting result is that the capacitance in plant is almost equivalent to that in the soil-plant system.

  2. Detection of cooling-induced membrane changes in the response of boar sperm to capacitating conditions.

    Science.gov (United States)

    Petrunkina, Anna M; Volker, Gabriele; Weitze, Karl-Fritz; Beyerbach, Martin; Töpfer-Petersen, Edda; Waberski, Dagmar

    2005-05-01

    There is a need for methods of rapid and sensitive sperm function assessment. As spermatozoa are not able to fertilize an oocyte before having undergone a series of complex physiological changes collectively called capacitation, it is logical to assess sperm function under fertilizing conditions in vitro. In this study, the responsiveness of sperm to capacitating conditions in vitro was monitored by changes in sperm response to ionophore and by changes in the amount of intracellular calcium ions in stored boar semen. Boar semen was diluted at 32 and 20 degrees C and stored for 24 and 72 h at 16 and 10 degrees C. Ionophore-induced changes and increased intracellular calcium ion content in boar spermatozoa were recorded by flow cytometry and found to progress as a function of time during incubation under capacitating conditions. All responsiveness parameters (increases in proportions of membrane-defective spermatozoa, acrosome-reacted spermatozoa, and cells with high intracellular calcium levels) were shown to be sensitive to subtle physiological changes occurring at low storage temperatures. The initial levels of sperm with a high calcium content were higher in semen stored at 10 degrees C, but the accumulation of internal calcium was lower than in semen stored at 16 degrees C. The loss of membrane integrity and increase in the proportion of acrosome-reacted cells were higher in semen stored at 10 degrees C. Dilution at 20 degrees C had no negative effect on membrane integrity or responsiveness to capacitating conditions. There was no significant difference between semen stored for 24 and 72 h in terms of membrane integrity, acrosome reaction, and intracellular calcium after capacitation treatment. However, dynamics of cell death and acrosome reaction in response to capacitating conditions were somewhat accelerated after 72 h storage, especially in semen stored at 10 degrees C. It can be concluded that the simultaneous use of the sperm membrane responsiveness and

  3. Energy-Efficient Capacitance-to-Digital Converters for Low-Energy Sensor Nodes

    KAUST Repository

    Omran, Hesham

    2015-11-01

    Energy efficiency is a key requirement for wireless sensor nodes, biomedical implants, and wearable devices. The energy consumption of the sensor node needs to be minimized to avoid battery replacement, or even better, to enable the device to survive on energy harvested from the ambient. Capacitive sensors do not consume static power; thus, they are attractive from an energy efficiency perspective. In addition, they can be employed in a wide range of sensing applications. However, the sensor readout circuit–i.e., the capacitance-to-digital converter (CDC)–can be the dominant source of energy consumption in the system. Thus, the development of energy-efficient CDCs is crucial to minimizing the energy consumption of capacitive sensor nodes. In the first part of this dissertation, we propose several energy-efficient CDC architectures for low-energy sensor nodes. First, we propose a digitally-controlled coarsefine multislope CDC that employs both current and frequency scaling to achieve significant improvement in energy efficiency. Second, we analyze the limitations of successive approximation (SAR) CDC, and we address these limitations by proposing a robust parasitic-insensitive opamp-based SAR CDC. Third, we propose an inverter-based SAR CDC that achieves an energy efficiency figure-of-merit (FoM) of 31fJ/Step, which is the best energy efficiency FoM reported to date. Fourth, we propose a differential SAR CDC with quasi-dynamic operation to maintain excellent energy efficiency for a scalable sample rate. In the second part of this dissertation, we study the matching properties of small integrated capacitors, which are an integral component of energy-efficient CDCs. Despite conventional wisdom, we experimentally illustrate that the mismatch of small capacitors can be directly measured, and we report mismatch measurements for subfemtofarad integrated capacitors. We also correct the common misconception that lateral capacitors match better than vertical capacitors

  4. Verification of overlap and fringing capacitance models for MOSFETs

    Science.gov (United States)

    Wakita, Naoki; Shigyo, Naoyuki

    2000-06-01

    Parasitic capacitance and resistance limit the VLSI device performance. Hence, a circuit model is needed to treat these effects correctly. This article focuses on the circuit models for the overlap capacitance ( Cgd,overlap) and the fringing capacitance ( Cgd,fringe) of MOSFETs. Comparisons between the models and the device simulations are carried out for verification of the models. Also, a limitation of Cgd,fringe model for a future device miniaturization is found based on SIA Road Map. We propose a modified Cgd,fringe model. The effectiveness of the modified model is demonstrated using two circuits.

  5. Nanoporous activated carbon cloth for capacitive deionization of aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Han-Jun [Department of Materials Science, Hanseo University, Seosan, 352-820 (Korea, Republic of); Lee, Jong-Ho [Department of Chemistry, Hanseo University, Seosan, 352-820 (Korea, Republic of); Ahn, Hong-Joo [Korea Atomic Energy Research Institute, Daejeon, 305-600 (Korea, Republic of); Jeong, Yongsoo [Korea Institute of Machinery and Materials, Changwon, 641-010 (Korea, Republic of); Kim, Young-Jig [Department of Metallurgical Engineering, Sungkyunkwan University, Suwon, 440-746 (Korea, Republic of); Chi, Choong-Soo [School of Advanced Materials Engineering, Kookmin University, Seoul, 136-702 (Korea, Republic of)]. E-mail: cschi@kookmin.ac.kr

    2006-09-25

    Activated nanostructured-carbon cloths with a high ratio of surface area to volume are used as electrode for capacitive deionization. The electrochemical properties on capacitive deionization for NaCl solution have been investigated to improve efficiency of capacitive deionization properties from aqueous solution, employing chemical surface-modification by etching in alkaline and acidic solution. The removal efficiency of inorganic salts of activated carbon cloths by chemical modification significantly increased. Specially the carbon cloth surface modified in HNO{sub 3} showed an effect of improvement in the CDI efficiency due to not only ion adsorption by an electric double layer, but also electron transfer by Faradaic reaction.

  6. Bloch inductance in small-capacitance Josephson junctions

    OpenAIRE

    Zorin, A. B.

    2005-01-01

    We show that the electrical impedance of a small-capacitance Josephson junction includes besides the capacitive term $-i/\\omega C_B$ also an inductive term $i\\omega L_B$. Similar to the known Bloch capacitance $C_B(q)$, the Bloch inductance $L_B(q)$ also depends periodically on the quasicharge $q$, and its maximum value achieved at $q=e (\\textrm{mod} 2e)$ always exceeds the value of the Josephson inductance of this junction $L_J(\\phi)$ at fixed $\\phi=0$. The effect of the Bloch inductance on ...

  7. Flexible transparent iontronic film for interfacial capacitive pressure sensing.

    Science.gov (United States)

    Nie, Baoqing; Li, Ruya; Cao, Jennifer; Brandt, James D; Pan, Tingrui

    2015-10-21

    A flexible, transparent iontronic film is introduced as a thin-film capacitive sensing material for emerging wearable and health-monitoring applications. Utilizing the capacitive interface at the ionic-electronic contact, the iontronic film sensor offers a large unit-area capacitance (of 5.4 μF cm(-2) ) and an ultrahigh sensitivity (of 3.1 nF kPa(-1) ), which is a thousand times greater than that of traditional solid-state counterparts. PMID:26333011

  8. Correcting For Capacitance In Tests Of Solar Cells

    Science.gov (United States)

    Mueller, Robert L.

    1995-01-01

    Modified procedure for testing solar photovoltaic cells and modified software for processing test data provide corrections for effects of cell capacitance. Procedure and software needed because (a) some photovoltaic devices (for example, silicon solar cells with back-surface field region) store minority charge carriers in cell junction and thus exhibit significant capacitance, (b) capacitance affects current-vs.-voltage (I-V) measurements made when transient load connected to cell, and (c) transient load used in unmodified version of test procedure. Corrected I-V curve obtained in test of solar cell according to modified procedure approximates true cell voltage vs. cell current more closely.

  9. Electrochemical Capacitance DNA Sensing at Hairpin-Modified Au Electrodes

    OpenAIRE

    Joel Rivera-Gandía; Maria del Mar Maldonado; Yarimar De La Torre-Meléndez; Edwin O. Ortiz-Quiles; Vargas-Barbosa, Nella M.; Cabrera, Carlos R.

    2011-01-01

    An interfacial capacitance measurement electrochemical technique has been used for the sensing of self-assembled DNA hairpin probes (M. tuberculosis and B. anthracis) attached to Au electrodes. The double-layer capacitance (Cdl) was determined with electrochemical perturbations from 0.2 V to 0.5 V versus Ag/AgCl at a Au/M. tuberculosis DNA hairpin probe at surface coverage Au electrodes. The capacitance study was done at pH 7, which was necessary to maintain the M. tuberculosis and B. anthrac...

  10. Developing capacitive equipment on-line monitoring intelligence software

    Science.gov (United States)

    Zhang, Weicong; Yang, Lichun

    2011-12-01

    In order to improve the safety and reliability of capacitive equipment developed online monitoring system of capacitive equipment dielectric loss. Introduce the structure and function of the software, based on the B/S skeleton, uses the modular design, improve the readability and scalability. Detail the design of communication module, parameter setting module, data acquisition and processing module, the user management module, database systems, etc. The entire process is given. By testing the monitoring software work is stable, reliable, long-term continuous and effective monitoring capacitive equipment various insulation data, can satisfy the requirements on site application.

  11. 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...... low 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...

  12. Touch mode micromachined capacitive pressure sensor with signal conditioning electronics

    DEFF Research Database (Denmark)

    Fragiacomo, Giulio; Eriksen, Gert F.; Christensen, Carsten;

    2010-01-01

    In the last decades, pressure sensors have been one of the greatest successes of the MEMS industry. Many companies are using them in a variety of applications from the automotive to the environmental field. Currently piezoresistive pressure sensors are the most developed, and a well established...... technology to design and fabricate these sensors has been implemented. Capacitive pressure sensing, on the other hand, is still an open and really promising field. Results Capacitive microsensors were designed and fabricated (Fig. 1) and an analytical model for touch mode regime, which fitted accurately the...... is therefore to develop new technologies based on capacitive sensing to be able to fulfil future requirements in this field....

  13. Atomistic simulations of aromatic polyurea and polyamide for capacitive energy storage

    Science.gov (United States)

    Dong, Rui; Ranjan, V.; Buongiorno Nardelli, Marco; Bernholc, J.

    2015-07-01

    Materials for capacitive energy storage with high energy density and low loss are desired in many fields. We investigate several polymers with urea and amide functional groups using density functional theory and classical molecular dynamics simulations. For aromatic polyurea (APU) and para-aramid (PA), we find several nearly energetically degenerate ordered structures, while meta-aromatic polyurea (mAPU) tends to be rotationally disordered along the polymer chains. Simulated annealing of APU and PA structures results in the formation of hydrogen-bonded sheets, highlighting the importance of dipole-dipole interactions. In contrast, hydrogen bonding does not play a significant role in mAPU, hence the propensity to disorder. We find that the disordered structures with misaligned chains have significantly larger dielectric constants, due to significant increase in the free volume, which leads to easier reorientation of dipolar groups in the presence of an electric field. Large segment motion is still not allowed below the glass transition temperature, which explains the experimentally observed very low loss at high field and elevated temperature. However, the degree of disorder needs to be controlled, because highly entangled structures diminish the free dipoles and decrease permittivity. Among the considered materials, mAPU is the most promising dielectric for capacitive energy storage, but the concept of increasing permittivity while maintaining low loss through disorder-induced free volume increase is generally applicable and provides an alternative pathway for the design of high-performance dielectrics for capacitive energy storage.

  14. Influence of nonelectrostatic ion-ion interactions on double-layer capacitance

    Science.gov (United States)

    Zhao, Hui

    2012-11-01

    Recently a Poisson-Helmholtz-Boltzmann (PHB) model [Bohinc , Phys. Rev. EPLEEE81539-375510.1103/PhysRevE.85.031130 85, 031130 (2012)] was developed by accounting for solvent-mediated nonelectrostatic ion-ion interactions. Nonelectrostatic interactions are described by a Yukawa-like pair potential. In the present work, we modify the PHB model by adding steric effects (finite ion size) into the free energy to derive governing equations. The modified PHB model is capable of capturing both ion specificity and ion crowding. This modified model is then employed to study the capacitance of the double layer. More specifically, we focus on the influence of nonelectrostatic ion-ion interactions on charging a double layer near a flat surface in the presence of steric effects. We numerically compute the differential capacitance as a function of the voltage under various conditions. At small voltages and low salt concentrations (dilute solution), we find out that the predictions from the modified PHB model are the same as those from the classical Poisson-Boltzmann theory, indicating that nonelectrostatic ion-ion interactions and steric effects are negligible. At moderate voltages, nonelectrostatic ion-ion interactions play an important role in determining the differential capacitance. Generally speaking, nonelectrostatic interactions decrease the capacitance because of additional nonelectrostatic repulsion among excess counterions inside the double layer. However, increasing the voltage gradually favors steric effects, which induce a condensed layer with crowding of counterions near the electrode. Accordingly, the predictions from the modified PHB model collapse onto those computed by the modified Poisson-Boltzmann theory considering steric effects alone. Finally, theoretical predictions are compared and favorably agree with experimental data, in particular, in concentrated solutions, leading one to conclude that the modified PHB model adequately predicts the diffuse

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

    OpenAIRE

    J.F. Lazcano-Reyes; Montiel, J.L.; Medrano, A.

    2013-01-01

    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, ...

  16. Mechano-capacitive properties of polarized membranes.

    Science.gov (United States)

    Mosgaard, Lars D; Zecchi, Karis A; Heimburg, Thomas

    2015-10-28

    Biological membranes are capacitors that can be charged by applying a field across the membrane. The charges on the capacitor exert a force on the membrane that leads to electrostriction, i.e. a thinning of the membrane. Since the force is quadratic in voltage, negative and positive voltage have an identical influence on the physics of symmetric membranes. However, this is not the case for a membrane with an asymmetry leading to a permanent electric polarization. Positive and negative voltages of identical magnitude lead to different properties. Such an asymmetry can originate from a lipid composition that is different on the two monolayers of the membrane, or from membrane curvature. The latter effect is called 'flexoelectricity'. As a consequence of permanent polarization, the membrane capacitor is discharged at a voltage different from zero. This leads to interesting electrical phenomena such as outward or inward rectification of membrane permeability. Here, we introduce a generalized theoretical framework, that treats capacitance, polarization, flexoelectricity, piezoelectricity and thermoelectricity in the same language. We show applications to electrostriction, membrane permeability and piezoelectricity and thermoelectricity close to melting transitions, where such effects are especially pronounced. PMID:26324950

  17. Thermodynamic cycle analysis for capacitive deionization.

    Science.gov (United States)

    Biesheuvel, P M

    2009-04-01

    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 solution as an ideal gas of pointlike particles. The work input is fully utilized to decrease the entropy of the outflowing streams compared to that of the inflow. Based on the Gouy-Chapman-Stern (GCS) model for planar diffuse polarization layers-with and without including additional ion volume constraints in the diffuse part of the double layer-we analyze the electric work input during charging and the work output during discharging, for a reversible charging-discharging cycle. We present a graphical thermodynamic cycle analysis for the reversible net work input during one full cycle of batchwise operation of CDI based on the charge-voltage relations for different ionic strengths. For the GCS model, an analytical solution is derived for the charge efficiency Lambda, which is the number of salt molecules removed per electron transferred from one electrode to the other. Only in the high voltage limit and for an infinite Stern layer capacity does Lambda approach unity. PMID:19167009

  18. Energy recovery in membrane capacitive deionization.

    Science.gov (United States)

    Długołęcki, Piotr; van der Wal, Albert

    2013-05-01

    Membrane capacitive deionization (MCDI) is a water desalination technology based on applying a cell voltage between two oppositely placed porous carbon electrodes. In front of each electrode, an ion-exchange membrane is positioned, and between them, a spacer is situated, which transports the water to be desalinated. In this work, we demonstrate for the first time that up to 83% of the energy used for charging the electrodes during desalination can be recovered in the regeneration step. This can be achieved by charging and discharging the electrodes in a controlled manner by using constant current conditions. By implementing energy recovery as an integral part of the MCDI operation, the overall energy consumption can be as low as 0.26 (kW·h)/m(3) of produced water to reduce the salinity by 10 mM, which means that MCDI is more energy efficient for treatment of brackish water than reverse osmosis. Nevertheless, the measured energy consumption is much higher than the thermodynamically calculated values for desalinating the water, and therefore, a further improvement in thermodynamic efficiency will be needed in the future. PMID:23477563

  19. Complementary surface charge for enhanced capacitive deionization.

    Science.gov (United States)

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

    2016-04-01

    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 cell to examine their salt removal at a fixed charging voltage and both reduced and opposite polarity discharge voltages, and subsequently compared to the salt removal of untreated electrodes. Substantially improved salt removal due to chemical surface charge and the use of a discharge voltage of opposite sign to the charging voltage is clearly demonstrated in these CDI cycling tests, an observation which for the first time validates both enhanced CDI and extended-voltage CDI effects predicted by the Donnan model [Biesheuvel et al., Colloids Interf. Sci. Comm., 10.1016/j.colcom.2015.12.001 (2016)]. Our experimental and theoretical results demonstrate that the use of carbon electrodes with optimized chemical surface charge can extend the CDI working voltage window through discharge voltages of opposite sign to the charging voltage, which can significantly enhance the salt adsorption capacity of CDI electrodes. Thus, in addition to carbon pore size distribution, chemical surface charge in carbon micropores is considered foundational for salt removal in CDI cells. PMID:26878361

  20. Capacitance Probe Resonator for Multichannel Electrometer

    Science.gov (United States)

    Blaes, Brent R.; Schaefer, Rembrandt T> Glaser, Robert J.

    2012-01-01

    A multichannel electrometer voltmeter has been developed that employs a mechanical resonator with voltage-sensing capacitance-probe electrodes that enable high-impedance, high-voltage, radiation-hardened measurement of an Internal Electrostatic Discharge Monitor (IESDM) sensor. The IESDM is new sensor technology targeted for integration into a Space Environmental Monitor (SEM) subsystem used for the characterization and monitoring of deep dielectric charging on spacecraft. The resonator solution relies on a non-contact, voltage-sensing, sinusoidal-varying capacitor to achieve input impedances as high as 10 petaohms as determined by the resonator materials, geometries, cleanliness, and construction. The resonator is designed with one dominant mechanical degree of freedom, so it resonates as a simple harmonic oscillator and because of the linearity of the variable sense capacitor to displacement, generates a pure sinusoidal current signal for a fixed input voltage under measurement. This enables the use of an idealized phase-lock sensing scheme for optimal signal detection in the presence of noise.

  1. Acoustic lens for capacitive micromachined ultrasonic transducers

    International Nuclear Information System (INIS)

    Capacitive micromachined ultrasonic transducers (CMUTs) have great potential to compete with traditional piezoelectric transducers in therapeutic ultrasound applications. In this paper we have designed, fabricated and developed an acoustic lens formed on the CMUT to mechanically focus ultrasound. The acoustic lens was designed based on the paraxial theory and made of silicone rubber for acoustic impedance matching and encapsulation. The CMUT was fabricated based on the local oxidation of silicon (LOCOS) and fusion-bonding. The fabricated CMUT was verified to behave like an electromechanical resonator in air and exhibited wideband response with a center frequency of 2.2 MHz in immersion. The fabrication for the acoustic lens contained two consecutive mold castings and directly formed on the surface of the CMUT. Applied with ac burst input voltages at the center frequency, the CMUT with the acoustic lens generated an output pressure of 1.89 MPa (peak-to-peak) at the focal point with an effective focal gain of 3.43 in immersion. Compared to the same CMUT without a lens, the CMUT with the acoustic lens demonstrated the ability to successfully focus ultrasound and provided a viable solution to the miniaturization of the multi-modality forward-looking endoscopes without electrical focusing. (paper)

  2. 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 ...

  3. Combinatorial Algorithms for Capacitated Network Design

    CERN Document Server

    Hajiaghayi, MohammadTaghi; Kortsarz, Guy; Nutov, Zeev

    2011-01-01

    We focus on designing combinatorial algorithms for the Capacitated Network Design problem (Cap-SNDP). The Cap-SNDP is the problem of satisfying connectivity requirements when edges have costs and hard capacities. We begin by showing that the Group Steiner tree problem (GST) is a special case of Cap-SNDP even when there is connectivity requirement between only one source-sink pair. This implies the first poly-logarithmic lower bound for the Cap-SNDP. We next provide combinatorial algorithms for several special cases of this problem. The Cap-SNDP is equivalent to its special case when every edge has either zero cost or infinite capacity. We consider a special case, called Connected Cap-SNDP, where all infinite-capacity edges in the solution are required to form a connected component containing the sinks. This problem is motivated by its similarity to the Connected Facility Location problem [G+01,SW04]. We solve this problem by reducing it to Submodular tree cover problem, which is a common generalization of Con...

  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. An ultra-small capacitance Josephson junction

    International Nuclear Information System (INIS)

    We consider a voltage biased ultra-small capacitance Josephson junction, with the coupling to the external source containing both resistive and inductive elements. In addition we include a phenomenological coupling to an external heat bath. Our goal is to extend and generalize previous studies of current biased ultra-small junctions. Charging effects, due to the presence of discrete charge carriers in the junction, play a crucial role. In particular we find an infinite resistance branch in the I-V characteristic for a d.c. bias, and resistive steps in the I-V curve when the external bias contains an additional a.c. component. These effects are reminiscent of the 'Coulomb blockade' and the inverse Shapiro steps, respectively, predicted earlier in the context of current biased circuits. As a response to an a.c. voltage bias we also predict spikes of the voltage across the junction and a noisy background, when this voltage is plotted as a function of either the external d.c. biasing voltage or the external frequency. Our analysis shows that various circuitry components may qualitatively affect the response of the junction to an external bias. (authors)

  6. Spatial resolution in electrical capacitance tomography

    CERN Document Server

    Lucas, Jérôme; Oussar, Yacine; Holé, Stéphane

    2015-01-01

    Electrical Capacitance Tomography (ECT) is an imaging technique providing the distribution of permittivity in a medium by the mean of electrodes. As for any imaging systems, the reachable spatial resolution is a key parameter. In this paper the spatial resolution of ECT sensors is analyzed in terms of the accuracy of an object position and of the ability to distinguish between two close objects. Cylindrical geometry sensors are particularly studied and the example of a square geometry sensor is used to show how to study any other geometries. In cylindrical geometries, it is shown that a 50% gap between electrodes is a good compromise and that increasing the number of electrodes improves the spatial resolution near the electrodes but decreases the spatial resolution in the center. The best spatial resolution at the center of the sensor is obtained with 3 or 4 electrodes. In the square geometry studied, it is shown that a better distribution of the spatial resolution is obtained when there are electrodes in the...

  7. Effects of Imperfect Quality and Defective Items on Economic Production Lot Size

    Institute of Scientific and Technical Information of China (English)

    Raafat; N; Ibrahim; Paul; Lochert

    2002-01-01

    The classical EPQ model has been used for a long ti me and is widely accepted and implemented. Nevertheless, the analysis for finding an economic lot size has based on a number of unrealistic assumptions. A common unrealistic assumption in using EPQ is that all units produced are of good quali ty. The classical EPQ model shows that the optimal lot size will generate minimum ma nufacturing cost, thus producing minimum setup cost and inventory cost. However, this is only true if all products manufactured...

  8. Heuristic procedures for a stochastic lot-sizing problem in make-to-order manufacturing

    OpenAIRE

    Dellaert, Nico; Melo, M. T.

    1995-01-01

    textabstractWe consider a single item, uncapacitated stochastic lot-sizing problem motivated by a Dutch make-to-order company producing steel pipes. Since no finished goods inventory is kept, a delivery date is fixed upon arrival of each order. The objective is to determine the optimal size of production lots so that delivery dates are met as closely as possible with a limited number of set-ups. Orders that are not satisfied on time are backordered and a penalty cost is incurred in those case...

  9. Field Performance of Differentially Deteriorated Seed Lots of Maize (Zea mays) under Different Irrigation Treatments

    OpenAIRE

    Kazem GHASSEMI-GOLEZANI; Bahareh DALIL; Mohammad MOGHADDAM; Yaeghoob RAEY

    2011-01-01

    A sub-sample of maize (cv. KSC301) seeds was kept as control or vigorous seed lot and two other sub-samples with about 16% moisture content were artificially deteriorated at 40C for 16 and 18 days. The three seed lots had seed viabilities of 99% (V1), 91% (V2) and 79% (V3). Laboratory tests were carried out as CR design with four replicates. However, the field experiment was conducted as factorial based on RCB design with three replicates to investigate the performance of differentiall...

  10. Design of Excitation Capacitance for Self-Excited Induction Generator

    Directory of Open Access Journals (Sweden)

    Swati Devabhaktuni

    2011-12-01

    Full Text Available This paper presents simple and accurate approach to compute the minimum value of capacitance required for initiating the voltage build-up in a three-phase selfexcited induction generator. Based on the steady-state equivalent circuit model different numerical methods for solving frequency are known from previous literature, which are of 6th order polynomial. In this paper the order of the polynomial is reduced to the 4thorder frequency with a new, simple and direct method is developed to find the capacitance requirement. Critical values of the impedance and speed, below which the machine fails to self excite irrespective of the capacitance used, are found to exist. Closed form solutions for capacitance are derived for no-load and RL loads. Experimental results obtained on a 3.5kW induction machine confirm the feasibility and accuracy of the proposed method.

  11. Segmented Capacitance Sensor with Partially Released Inactive Segments

    Directory of Open Access Journals (Sweden)

    Lev Jakub

    2015-09-01

    Full Text Available Material throughput measurement is important for many applications, for example yield maps creation or control of mass flow in stationary lines. Quite perspective can be the capacitive throughput method. Segmented capacitance sensor (SCS is discussed in this paper. SCS is a compromise between simple capacitive throughput sensors and electrical capacitance tomography sensors. The SCS variant with partially released inactive segments is presented. The mathematical model of SCS was created and verified by measurements. A good correspondence between measured and computed values was found and it can be stated that the proposed mathematical model was verified. During measurement the voltage values on the inactive segments were monitored as well. On the basis of the measurement there was found that these values are significantly influenced by material distribution.

  12. 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)

  13. Composite metal-oxide device has voltage sensitive capacitance

    Science.gov (United States)

    Mattauch, R. J.; Viola, T. J., Jr.

    1970-01-01

    Device with step function variation of the capacitance is useful for voltage-controlled oscillator circuits and as a voltage-sensitive switch. Simplicity of construction makes the device suitable for large-scale integration, microelectronic circuits.

  14. Enhancement of the carbon electrode capacitance by brominated hydroquinones

    Science.gov (United States)

    Gastol, Dominika; Walkowiak, Jedrzej; Fic, Krzysztof; Frackowiak, Elzbieta

    2016-09-01

    This paper presents supercapacitors utilizing new redox-active electrolytes with bromine species. Two sources of Br specimen were investigated, i.e. dibromodihydroxybenzene dissolved in KOH and potassium bromide dissolved in KOH with hydroxybenzene additive. KOH-activated carbon, exhibiting a well-developed porosity, was incorporated as an electrode material. The tested systems revealed a capacitance enhancement explained by Br- and partial BrO3- redox activity. The optimisation of the electrolyte concentration resulted in a capacitance value of 314 F g-1 achieved at 1.1 V voltage range. Good cyclability performance (11% capacitance loss) combined with a high capacitance value (244 F g-1) were obtained for the system operating in 0.2 mol L- 1 C6H4Br2O2 in 2 mol L-1 KOH electrolytic solution.

  15. 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

  16. Capacitive Sensors for Measuring Masses of Cryogenic Fluids

    Science.gov (United States)

    Nurge, Mark; Youngquist, Robert

    2003-01-01

    An effort is under way to develop capacitive sensors for measuring the masses of cryogenic fluids in tanks. These sensors are intended to function in both microgravitational and normal gravitational settings, and should not be confused with level sensors, including capacitive ones. A sensor of this type is conceptually simple in the sense that (1) it includes only one capacitor and (2) if properly designed, its single capacitance reading should be readily convertible to a close approximation of the mass of the cryogenic fluid in the tank. Consider a pair of electrically insulated electrodes used as a simple capacitive sensor. In general, the capacitance is proportional to the permittivity of the dielectric medium (in this case, a cryogenic fluid) between the electrodes. The success of design and operation of a sensor of the present type depends on the accuracy of the assumption that to a close approximation, the permittivity of the cryogenic fluid varies linearly with the density of the fluid. Data on liquid nitrogen, liquid oxygen, and liquid hydrogen, reported by the National Institute of Standards and Technology, indicate that the permittivities and densities of these fluids are, indeed, linearly related to within a few tenths of a percent over the pressure and temperature regions of interest. Hence, ignoring geometric effects for the moment, the capacitance between two electrodes immersed in the fluid should vary linearly with the density, and, hence, with the mass of the fluid. Of course, it is necessary to take account of the tank geometry. Because most cryogenic tanks do not have uniform cross sections, the readings of level sensors, including capacitive ones, are not linearly correlated with the masses of fluids in the tanks. In a sensor of the present type, the capacitor electrodes are shaped so that at a given height, the capacitance per unit height is approximately proportional to the cross-sectional area of the tank in the horizontal plane at that

  17. Probing Quantum Capacitance in a 3D Topological Insulator

    Science.gov (United States)

    Kozlov, D. A.; Bauer, D.; Ziegler, J.; Fischer, R.; Savchenko, M. L.; Kvon, Z. D.; Mikhailov, N. N.; Dvoretsky, S. A.; Weiss, D.

    2016-04-01

    We measure the quantum capacitance and probe thus directly the electronic density of states of the high mobility, Dirac type two-dimensional electron system, which forms on the surface of strained HgTe. Here we show that observed magnetocapacitance oscillations probe—in contrast to magnetotransport—primarily the top surface. Capacitance measurements constitute thus a powerful tool to probe only one topological surface and to reconstruct its Landau level spectrum for different positions of the Fermi energy.

  18. Direct measurement of specific membrane capacitance in neurons.

    OpenAIRE

    Gentet, L.J.; Stuart, G J; Clements, J D

    2000-01-01

    The specific membrane capacitance (C(m)) of a neuron influences synaptic efficacy and determines the speed with which electrical signals propagate along dendrites and unmyelinated axons. The value of this important parameter remains controversial. In this study, C(m) was estimated for the somatic membrane of cortical pyramidal neurons, spinal cord neurons, and hippocampal neurons. A nucleated patch was pulled and a voltage-clamp step was applied. The exponential decay of the capacitative char...

  19. Simultaneous capacitance and amperometric measurements of exocytosis: a comparison.

    OpenAIRE

    Oberhauser, A F; Robinson, I M; Fernandez, J. M.

    1996-01-01

    We measured the exocytotic response induced by flash photolysis of caged compounds in isolated mast cells and chromaffin cells. Vesicle fusion was measured by monitoring the cell membrane capacitance. The release of vesicular contents was followed by amperometry. In response to a GTP gamma S stimulus we found that the time integral of the amperometric current could be superimposed on the capacitance trace. This shows that the integrated amperometric signal provides an alternative method of me...

  20. Graphene-based quantum capacitance wireless vapor sensors

    OpenAIRE

    Deen, David A.; Olson, Eric J.; Ebrish, Mona A.; Koester, Steven J.

    2013-01-01

    A wireless vapor sensor based upon the quantum capacitance effect in graphene is demonstrated. The sensor consists of a metal-oxide-graphene variable capacitor (varactor) coupled to an inductor, creating a resonant oscillator circuit. The resonant frequency is found to shift in proportion to water vapor concentration for relative humidity (RH) values ranging from 1% to 97% with a linear frequency shift of 5.7 +- 0.3 kHz / RH%. The capacitance values extracted from the wireless measurements ag...

  1. 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....

  2. Capacitance extraction from complex 3D interconnect structures

    Energy Technology Data Exchange (ETDEWEB)

    Cartwright, D.; Csanak, G.; George, D.; Walker, R.; Kuprat, A. [Los Alamos National Lab., NM (United States). Theoretical Div.; Dengi, A.; Grobman, W. [Motorola, Austin, TX (United States)

    1999-06-01

    A new tool has been developed for calculating the capacitance matrix for complex 3D interconnect structures involving multiple layers of irregularly shaped interconnect, imbedded in different dielectric materials. This method utilizes a new 3D adaptive unstructured grid capability, and a linear finite element algorithm. The capacitance is determined from the minimum in the total system energy as the nodes are varied to minimize the error in the electric field in the dielectric(s).

  3. Probing Quantum Capacitance in a 3D Topological Insulator.

    Science.gov (United States)

    Kozlov, D A; Bauer, D; Ziegler, J; Fischer, R; Savchenko, M L; Kvon, Z D; Mikhailov, N N; Dvoretsky, S A; Weiss, D

    2016-04-22

    We measure the quantum capacitance and probe thus directly the electronic density of states of the high mobility, Dirac type two-dimensional electron system, which forms on the surface of strained HgTe. Here we show that observed magnetocapacitance oscillations probe-in contrast to magnetotransport-primarily the top surface. Capacitance measurements constitute thus a powerful tool to probe only one topological surface and to reconstruct its Landau level spectrum for different positions of the Fermi energy. PMID:27152818

  4. New Type Multielectrode Capacitance Sensor for Liquid Level

    International Nuclear Information System (INIS)

    This paper introduces the design of a new type multielectrode capacitance sensor for liquid level. The system regards electric field sensor MC33794 as the core and applies microcontroller MC9S12DJ128 to realize intelligent liquid level monitoring system, which overcomes the disadvantages of the traditional capacitance sensor, improves on the anti-jamming ability and the measurement precision and simplifies the system structure. Finally, the paper sums up the design of the system

  5. 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.

  6. 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.

  7. Thermo-hydro-geochemical modelling of the bentonite buffer. LOT A2 experiment

    Energy Technology Data Exchange (ETDEWEB)

    Sena, Clara; Salas, Joaquin; Arcos, David (Amphos 21 Consulting S.L., Barcelona (Spain))

    2010-12-15

    The Swedish Nuclear Fuel and waste management company (SKB) is conducting a series of long term buffer material (LOT) tests at the Aespoe Hard Rock Laboratory (HRL) to test the behaviour of the bentonite buffer under conditions similar to those expected in a KBS-3 deep geological repository for high level nuclear waste (HLNW). In the present work a numerical model is developed to simulate (i) the thermo-hydraulic, (ii) transport and (iii) geochemical processes that have been observed in the LOT A2 test parcel. The LOT A2 test lasted approximately 6 years, and consists of a 4 m long vertical borehole drilled in diorite rock, from the ground of the Aespoe HRL tunnel. The borehole is composed of a central heater, maintained at 130 deg C in the lower 2 m of the borehole, a copper tube surrounding the heater and a 100 mm thick ring of pre-compacted Wyoming MX-80 bentonite around the copper tube /Karnland et al. 2009/. The numerical model developed here is a 1D axis-symmetric model that simulates the water saturation of the bentonite under a constant thermal gradient; the transport of solutes; and, the geochemical reactions observed in the bentonite blocks. Two cases have been modelled, one considering the highest temperature reached by the bentonite (at 3 m depth in the borehole, where temperatures of 130 and 85 deg C have been recorded near the copper tube and near the granitic host rock, respectively) and the other case assuming a constant temperature of 25 deg C, representing the upper part of borehole, where the bentonite has not been heated. In the LOT A2 test, the initial partially saturated bentonite becomes progressively water saturated, due to the injection of Aespoe granitic groundwater at granite - bentonite interface. The transport of solutes during the bentonite water saturation stage is believed to be controlled by water uptake from the surrounding groundwater to the wetting front and, additionally, in the case of heated bentonite, by a cyclic evaporation

  8. Thermo-hydro-geochemical modelling of the bentonite buffer. LOT A2 experiment

    International Nuclear Information System (INIS)

    The Swedish Nuclear Fuel and waste management company (SKB) is conducting a series of long term buffer material (LOT) tests at the Aespoe Hard Rock Laboratory (HRL) to test the behaviour of the bentonite buffer under conditions similar to those expected in a KBS-3 deep geological repository for high level nuclear waste (HLNW). In the present work a numerical model is developed to simulate (i) the thermo-hydraulic, (ii) transport and (iii) geochemical processes that have been observed in the LOT A2 test parcel. The LOT A2 test lasted approximately 6 years, and consists of a 4 m long vertical borehole drilled in diorite rock, from the ground of the Aespoe HRL tunnel. The borehole is composed of a central heater, maintained at 130 deg C in the lower 2 m of the borehole, a copper tube surrounding the heater and a 100 mm thick ring of pre-compacted Wyoming MX-80 bentonite around the copper tube /Karnland et al. 2009/. The numerical model developed here is a 1D axis-symmetric model that simulates the water saturation of the bentonite under a constant thermal gradient; the transport of solutes; and, the geochemical reactions observed in the bentonite blocks. Two cases have been modelled, one considering the highest temperature reached by the bentonite (at 3 m depth in the borehole, where temperatures of 130 and 85 deg C have been recorded near the copper tube and near the granitic host rock, respectively) and the other case assuming a constant temperature of 25 deg C, representing the upper part of borehole, where the bentonite has not been heated. In the LOT A2 test, the initial partially saturated bentonite becomes progressively water saturated, due to the injection of Aespoe granitic groundwater at granite - bentonite interface. The transport of solutes during the bentonite water saturation stage is believed to be controlled by water uptake from the surrounding groundwater to the wetting front and, additionally, in the case of heated bentonite, by a cyclic evaporation

  9. Quantum Fluctuations of Mesoscopic Damped Circuit Involving Capacitance-Inductance Coupling at a Finite Temperature

    Science.gov (United States)

    Xu, Xing-Lei; Xu, Shi-Min; Li, Hong-Qi

    2008-06-01

    The quantization of mesoscopic damped circuit involving capacitance-inductance coupling is proposed by the method of thrice linear transformation and damped harmonic oscillator quantization. The quantum fluctuations of the charges and current of each loop are calculated by thermo-field dynamics (TFD) in thermal vacuum state, thermal coherent state and thermal squeezed state, respectively. It is shown that the quantum fluctuations of the charges and current not only depend on circuit inherent parameter and coupled magnitude, but also rely on squeezed coefficients, squeezed angle, environmental temperature and damped resistance. And, because of influence of environmental temperature and damped resistance, the quantum fluctuations increase with increasing temperature and decrease with prolonging time.

  10. Switchless charge-discharge circuit for electrical capacitance tomography

    International Nuclear Information System (INIS)

    The main factor limiting the performance of electrical capacitance tomography (ECT) is an extremely low value of inter-electrode capacitances. The charge-discharge circuit is a well suited circuit for a small capacitance measurement due to its immunity to noise and stray capacitance, although it has a problem associated with a charge injected by the analogue switches, which results in a dc offset. This paper presents a new diode-based circuit for capacitance measurement in which a charge transfer method is realized without switches. The circuit was built and tested in one channel configuration with 16 multiplexed electrodes. The performance of the elaborated circuit and a comparison with a classic charge-discharge circuit are presented. The elaborated circuit can be used for sensors with inter-electrode capacitances not lower than 10 fF. The presented approach allows us to obtain a similar performance to the classic charge-discharge circuit, but has a simplified design. A lack of the need to synchronize the analogue switches in the transmitter and the receiver part of this circuit could be a desirable feature in the design of measurement systems integrated with electrodes. (paper)

  11. Home Automation System Using Capacitive Touchscreen

    Directory of Open Access Journals (Sweden)

    Yash Inaniya

    2014-06-01

    Full Text Available Technology has been constantly evolving and with the advent of touchscreen in human life , devices are much easier and simple to operate. This work is mainly focused on building home automation system which is more user friendly and thus can be operated by anyone. Earlier home automation systems were completely mechanically operated and thus required a lot of maintenance and were costly also. Now that human and computer interaction has been developed into a more wide and sophisticated field , designing and operating of intelligence system has been more user friendly than ever. Home automation is a system that helps a user to operate switching various appliances and lighting devices from a single input. The touchscreen used as input is much simpler to operate. Touchscreen has been widely accepted as the most comfortable input to be provided to the user. Not only they are easy to operate but they also give a sense of personal involvement which the user always appreciate. The materials used in this system are easily available in the local market so that the touch screen sytem is cost effective .

  12. Multi-Level Lot Sizing Problem with Deterioration Inventory and Disposal Costs

    Directory of Open Access Journals (Sweden)

    Mahmood Vahdani

    2016-02-01

    Full Text Available Abstract In this paper, the multi-level lot sizing problem which is used to determine the production lot sizes in industrial environments, has been investigated. A new problem which we refer to it as “multi-level lot sizing problem with deterioration inventory and disposal costs” is introduced. The aim of multi-level lot sizing problem is to determine the production quantity of production periods for each product in each level, such the the total cost containing production costs, holding costs and setup costs to be minimized. In the proposed model, the deterioration property of the inventory is assumed. Furthermore, disposal costs that represents the costs for removing the perishable inventories from the storage environments, is combined with the generalized model in order to make the model closer to reality. The aim of the new problem, are determining the production quantity of production periods for each product in each level, and determining the periods in which the perishable inventory to be disposed. Therefore, the disposal costs is considered in the objective function of the problem. Two meta heuristic algorithms consist of genetic algorithm and simulated annealing algorithm is used to solve the proposed problem. In order to compare the performance of the proposed algorithms with existing methods in the literature, instance problems are created, and the results are analyzed.

  13. Variation in quality of individual seeds within a seed lot of soybean (Glycine max (L.) Merrill).

    NARCIS (Netherlands)

    Illipronti, R.A.

    1997-01-01

    The research described in this thesis aimed at increasing insight into the sources of variation in quality attributes of individual seeds within a soybean seed lot, into the relations between physical attributes and performance of seeds in seed tests and in controlled seed production conditions, and

  14. Heuristic procedures for a stochastic lot-sizing problem in make-to-order manufacturing

    NARCIS (Netherlands)

    N.P. Dellaert (Nico); M.T. Melo

    1995-01-01

    textabstractWe consider a single item, uncapacitated stochastic lot-sizing problem motivated by a Dutch make-to-order company producing steel pipes. Since no finished goods inventory is kept, a delivery date is fixed upon arrival of each order. The objective is to determine the optimal size of produ

  15. Chinese plasma-derived products supply under the lot release management system in 2007-2011.

    Science.gov (United States)

    Zhang, Xuejun; Ye, Shengliang; Du, Xi; Yuan, Jing; Zhao, Chaoming; Li, Changqing

    2013-11-01

    In 2007, the Chinese State Food and Drug Administration (SFDA) implemented a management system for lot release of all plasma-derived products. Since then, there have been only a few systematic studies of the blood supply, which is a concern when considering the small amount of plasma collected per capita (approximately 3 L/1000 people). As a result, there may be a threat to the safety of the available blood supply. In this study, we examined the characteristics of the supply of Chinese plasma-derived products. We investigated the reports of lot-released biological products derived from all 8 national or regional regulatory authorities in China from 2007 to 2011. The market supply characteristics of Chinese plasma-derived products were analyzed by reviewing the changes in supply varieties, the batches of lot-released plasma-derived products and the actual supply. As a result, the national regulatory authorities can more accurately develop a specific understanding of the production and quality management information provided by Chinese plasma product manufacturers. The implementation of the lot release system further ensures the clinical validity of the plasma-derived products in China and improves the safety of using plasma-derived products. This work provides an assessment of the future Chinese market supply of plasma-derived products and can function as a theoretical basis for the establishment of hemovigilance. PMID:23856276

  16. Vacant urban lot soils and their potential to support ecosystem services

    Science.gov (United States)

    AimsUrban soils are the basis of many ecosystem services in cities. Here, we examine formerly residential vacant lot soils in Cleveland, Ohio and Detroit, Michigan, USA for their potential to provide multiple ecosystem services. We examine two key contrasts: 1) differences betwee...

  17. Field Performance of Differentially Deteriorated Seed Lots of Maize (Zea mays under Different Irrigation Treatments

    Directory of Open Access Journals (Sweden)

    Kazem GHASSEMI-GOLEZANI

    2011-11-01

    Full Text Available A sub-sample of maize (cv. KSC301 seeds was kept as control or vigorous seed lot and two other sub-samples with about 16% moisture content were artificially deteriorated at 40C for 16 and 18 days. The three seed lots had seed viabilities of 99% (V1, 91% (V2 and 79% (V3. Laboratory tests were carried out as CR design with four replicates. However, the field experiment was conducted as factorial based on RCB design with three replicates to investigate the performance of differentially deteriorated seed lots under four irrigation treatments (irrigation after 70, 90, 110 and 130 mm evaporation from class A pan. Germination and emergence times significantly increased with increasing seed deterioration, but mean viability percentage, seedling dry weight, seedling emergence and protein and grain yields decreased as seed deterioration increased. Even plants from less deteriorated seed lot (V2 with acceptable germination (91% showed 25.1% reduction in grain yield per unit area. The superiority of V1 to V2 seeds of maize increased as water limitation increased. Protein yield was also decreased as a result of seed deterioration. Seedling dry weight highly correlated with the field emergence and grain and protein yields. Thus, it is necessary to produce and cultivate high vigor seeds of maize, in order to ensure satisfactory yield achievement, particularly under adverse environmental conditions.

  18. A QUALITATIVE ANALYSIS OF BIOMASS FLOW SENSING BEHAVIOR USING CAPACITIVE TECHNIQUE

    OpenAIRE

    Rumana Tasnim; Sheroz Khan; Musse Mohamud; Atika Arshad

    2016-01-01

    Flowsensing technology from today’s application perspective has gained significant research interest over the past few years. Among the existing sensing techniques, electrostatic and capacitive sensing techniques have proven promising although cable capacitance and stray capacitance cause inaccuracy while measuring very small capacitances. The existing measurement circuit model is complicated and has flawed electrode arrangement. By sensing very small capacitive variation, the developed capac...

  19. The effect of surface transport on water desalination by porous electrodes undergoing capacitive charging

    CERN Document Server

    Shocron, Amit N

    2016-01-01

    Capacitive deionization (CDI) is a technology in which water is desalinated by ion electrosorption into the electric double layers (EDLs) of charging porous electrodes. In recent years significant advances have been made in modeling the charge and salt dynamics in a CDI cell, but the possible effect of surface transport within diffuse EDLs on these dynamics has not been investigated. We here present theory which includes surface transport in describing the dynamics of a charging CDI cell. Through our numerical solution to the presented models, the possible effect of surface transport on the CDI process is elucidated. While at some model conditions surface transport enhances the rate of CDI cell charging, counter-intuitively this additional transport pathway is found to slow down cell charging at other model conditions.

  20. 3. Mercury pollution in the Lot River system (France): fluxes and sedimentary record.

    Science.gov (United States)

    Schäfer, J.; Blanc, G.; Audry, S.; Bossy, C.; Vu Duc, L.; Lissalde, J.-P.

    2003-04-01

    We present first data on Hg concentrations and fluxes in the Lot River system (southwest France), known for its historic Zn and Cd pollution affecting seafood production in the Gironde Estuary. Present day Hg fluxes (1999-2000) were estimated from daily measured discharge and SPM concentrations and concentrations of particulate and dissolved Hg in monthly collected samples. The data show that Hg is essentially (up to 98 %) transported in the particulate phase. Particulate Hg concentrations in SPM show a distinct decrease between 1992 and 1999 but, since then, tend to increase in magnitude and variability. The evolution of Hg fluxes in the Lot River in 1992, 1994, 1995 and 1998-2001 reflect hydrological variations and the decrease of direct Hg inputs from the point source at the Riou-Mort River, draining a small watershed polluted by former mining and ore treatment. However, the data also indicate important Hg remobilization from the sediment by dredging due to lock construction along the Lot River. Mercury concentrations in sediment cores from a dam lake downstream of the Riou-Mort watershed are up to 30 mg.kg-1, i.e. more than 300-fold higher than geochemical background measured in the same riverbed upstream the confluence with the Riou-Mort River. In the sediment cores Hg from the Lot River dam lakes Hg concentration profiles are comparable to those of Cd and Zn. This indicates common sources and transport. Element ratios (e.g. Cd/Zn) in the sediment reflect SPM values and suggest an important Hg stock (7 t) in these sediments. Historic (˜40 years) Hg records in the sediment cores dated by using 137Cs activities and Cd-concentrations (e.g. Chernobyl accident and accidental Cd pollution in 1986) confirm the decreasing Hg level in SPM since the early nineties. Nevertheless Hg concentrations in the upper sediment and SPM remain high compared to background values from reference sites in the upper Lot River system.

  1. An Analytical Model for Fringing Capacitance in Double gate Hetero Tunnel FET and Analysis of effect of Traps and Oxide charges on Fringing Capacitance

    Directory of Open Access Journals (Sweden)

    Brinda Bhowmick

    2012-03-01

    Full Text Available In this paper fringe capacitance of double hetero gate Tunnel FET has been studied. The physical modelfor fringe capacitance is derived considering source gate overlap and gate drain non overlap. Inerface trap charge and oxide charges are also introduced under positive bias stress and hot carrier stress and their effect on fringe capacitance is also studied. The fringe capacitance is significant speed limiter in Double gate technology. The model is tested by comparing with simulation results obtained from Sentauras TCADsimulations.

  2. An Analytical Model for Fringing Capacitance in Double gate Hetero Tunnel FET and Analysis of effect of Traps and Oxide charges on Fringing Capacitance

    OpenAIRE

    Brinda Bhowmick; Srimanta Baishya

    2012-01-01

    In this paper fringe capacitance of double hetero gate Tunnel FET has been studied. The physical model for fringe capacitance is derived considering source gate overlap and gate drain non overlap. Inerface trap charge and oxide charges are also introduced under positive bias stress and hot carrier stress and their effect on fringe capacitance is also studied. The fringe capacitance is significant speed limiter in Double gate technology. The model is tested by comparing with simulation results...

  3. Extracellular signal-regulated kinases modulate capacitation of human spermatozoa.

    Science.gov (United States)

    Luconi, M; Barni, T; Vannelli, G B; Krausz, C; Marra, F; Benedetti, P A; Evangelista, V; Francavilla, S; Properzi, G; Forti, G; Baldi, E

    1998-06-01

    Recent evidence indicates the presence of p21 Ras and of a protein with characteristics similar to mitogen-activated protein kinases (MAPKs), also known as extracellular signal-regulated kinases (ERKs), in mammalian spermatozoa, suggesting the occurrence of the Ras/ERK cascade in these cells. In the present study we investigated the subcellular localization of ERKs and their biological functions in human spermatozoa. Immunohistochemistry, immunofluorescence, confocal microscopy, and immunoelectron microscopy demonstrated localization of ERKs in the postacrosomal region of spermatozoa. After stimulation of acrosome reaction with the calcium ionophore A23187 and progesterone, ERKs were mostly localized at the level of the equatorial region, indicating redistribution of these proteins in acrosome-reacted spermatozoa. Two proteins of 42 and 44 kDa that are tyrosine phosphorylated in a time-dependent manner during in vitro capacitation were identified as p42 (ERK-2) and p44 (ERK-1) by means of specific antibodies. The increase in tyrosine phosphorylation of these proteins during capacitation was accompanied by increased kinase activity, as determined by the ability of ERK-1 and ERK-2 to phosphorylate the substrate myelin basic protein. The role of this activity in the occurrence of sperm capacitation was also investigated by using PD098059, an inhibitor of the MAPK cascade. The presence of this compound during in vitro capacitation inhibits ERK activation and significantly reduces the ability of spermatozoa to undergo the acrosome reaction in response to progesterone. Since only capacitated spermatozoa are able to respond to progesterone, these data strongly indicate that ERKs are involved in the regulation of capacitation. In summary, our data demonstrate the presence of functional ERKs in human spermatozoa and indicate that these enzymes are involved in activation of these cells during capacitation, providing new insight in clarifying the molecular mechanisms and the

  4. Radioactive versus capacitance techniques for measuring soil water

    International Nuclear Information System (INIS)

    A field study was conducted to compared a capacitance probe and a neutron probe for use in measuring the soil water changes and the absolute values of soil water. The study was conducted using three plots each receiving different amounts of water by a surface drip irrigation system. The 50 mm PVC access tubes were installed using a machine to auger the holes. One hole was dug using a 50 mm bulk density probe and the remaining two holes were dug using a 54 mm soil sampling tube. The two probes were calibrated to this site. The capacitance probe measured both absorption and desorption of the soil water in the semi-dry site as well as the neutron probe. The capacitance probe gave slightly higher soil water values in the semi-dry plot than the neutron probe. However, both instruments tracked the changes reasonably well. In the wet site, both probes underpredicted the actual water content, but still tracked the changes. In the dry site, which had a poorly install access tube, the capacitance probe did not accurately predict the water content or changes, while the neutron probe did. The capacitance technique will provide acceptable soil water measurements if the access tube is properly installed and appropriate calibration used. (author). 4 refs, 4 figs, 1 tab

  5. 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.

  6. Low-Temperature Scanning Capacitance Probe for Imaging Electron Motion

    International Nuclear Information System (INIS)

    Novel techniques to probe electronic properties at the nanoscale can shed light on the physics of nanoscale devices. In particular, studying the scattering of electrons from edges and apertures at the nanoscale and imaging the electron profile in a quantum dot, have been of interest [1]. In this paper, we present the design and implementation of a cooled scanning capacitance probe that operates at liquid He temperatures to image electron waves in nanodevices. The conducting tip of a scanned probe microscope is held above the nanoscale structure, and an applied sample-to-tip voltage creates an image charge that is measured by a cooled charge amplifier [2] adjacent to the tip. The circuit is based on a low-capacitance, high- electron-mobility transistor (Fujitsu FHX35X). The input is a capacitance bridge formed by a low capacitance pinched-off HEMT transistor and tip-sample capacitance. We have achieved low noise level (0.13 e/VHz) and high spatial resolution (100 nm) for this technique, which promises to be a useful tool to study electronic behavior in nanoscale devices

  7. Logarithmic derivative method and system for capacitance measurement

    Science.gov (United States)

    Wu, Yichun; Wang, Lingzhi; Cai, Yuanfeng; Wu, Cunqiao

    2015-08-01

    A novel method based on logarithmic derivative is introduced to analyze multi-lifetime decay. As the discharge voltage signal of a RC circuit is a special kind of multi-lifetime exponential decay, the logarithmic derivative method can be used to measure single capacitance and multiple capacitances. With the logarithmic derivative method, a log(t) curve strongly peaked at precisely log(τ) is obtained, where the lifetime τ equals to RC. In a measurement system, if the resistance R is known, then the capacitance under test can be calculated. A logarithmic derivative curve fitting method is also presented, which has better anti-noise capability than the method that simply finds the maximum data on the peak. The curve fitting method can also be used for multiple capacitors measurement. To measure small capacitances, a large enough time window of the measuring instrument is required. Based on a field programmable gate array and a high speed analog-to-digital converter, a measurement system is developed. This system can provide the 16-bit resolution with sampling rate up to 250 MHz, which has a large enough time window for measuring lifetime shorter than 10-8 s. To reduce the amount of data needed to be stored and the noise due to the derivative treatment of transient data, the interpolation and noise-filter algorithms are employed. Experiments indicate that the logarithmic derivative method and system are suitable for the measurement of capacitances discharge and other exponential decay processes.

  8. Development and application of a real-time capacitive sensor.

    Science.gov (United States)

    Wongkittisuksa, Booncharoen; Limsakul, Chusak; Kanatharana, Proespichaya; Limbut, Warakorn; Asawatreratanakul, Punnee; Dawan, Supaporn; Loyprasert, Suchera; Thavarungkul, Panote

    2011-01-15

    A real-time capacitive sensor based on a potentiostatic step method was developed. It can display in real-time the evoked current waveform, capacitance and the electrical resistance of elements serially connected to the insulation layer on the electrode as a function of time as well as the ohmic resistance of the insulation layer. These features enable the user to observe the association and dissociation of the affinity binding pairs and to evaluate the insulating property of the electrode surface during measurement. The system allows the setting of potential pulse height, pulse interval, gain, filter, and sampling frequency, enabling the system to be more flexible. The performance of the system was firstly evaluated with equivalent circuits. Under suitable parameter settings it provided good accuracy of both the capacitance and resistance. Using the affinity binding pair of human serum albumin (HSA) and anti human serum albumin (anti-HSA) the measured capacitance change was used for the direct detection of HSA. The developed system provided the same sensitivity as the commercially available potentiostat (P>0.05). The proposed system was then applied to analyse HSA in real urine samples and the results agreed well with the immunoturbidimetric assay (P>0.05). The proposed system can be applied for capacitance measurement to directly detect other target analytes using different affinity binding pairs. Other applications such as kinetics analysis of the interaction between affinity bindings, thickness analysis, and the study of the insulation property of the modified layer are also promising. PMID:21087852

  9. Label-free RNA aptamer-based capacitive biosensor for the detection of C-reactive protein.

    Science.gov (United States)

    Qureshi, Anjum; Gurbuz, Yasar; Kallempudi, Saravan; Niazi, Javed H

    2010-08-28

    In this study, we report a novel aptamer-based capacitive label-free biosensor for monitoring transducing aptamer-protein recognition events, based on charge distribution under the applied frequency by non-Faradaic impedance spectroscopy (NFIS). This approach to capacitive biosensors is reported for the first time in this study, is reagent-less in processing and is developed using gold interdigitated (GID) capacitor arrays functionalized with synthetic RNA aptamers. The RNA atpamers served as biorecognition elements for C-reactive protein (CRP), a biomarker for cardiovascular disease risk (CVR). The signal is generated as a result of the change in relative capacitance occurring as a result of the formation of an RNA-CRP complex on GID capacitors with the applied AC electrical frequency (50-350 MHz). The dispersion peak of the capacitance curve was dependent on the CRP concentration and tends to shift toward lower frequencies, accompanied by the increase in relaxation time due to the increased size of the aptamer-CRP complex. The dissociation constant (K(d)) calculated from the non-linear regression analysis of the relative capacitance change with the applied frequency showed that strong binding of CRP occurred at 208 MHz (K(d) = 1.6 microM) followed by 150 MHz (K(d) = 4.2 microM) and 306 MHz (K(d) = 3.4 microM) frequencies. The dynamic detection range for CRP is determined to be within 100-500 pg ml(-1). Our results demonstrates the behavior of an RNA-protein complex on GID capacitors under an applied electric field, which can be extended to other pairs of affinity biomolecules as well as for the development of electrical biosensor systems for different applications, including the early diagnosis of diseases. PMID:20648264

  10. Quality Costs (IRR Impact on Lot Size Considering Work in Process Inventory

    Directory of Open Access Journals (Sweden)

    Misbah Ullaha

    2014-06-01

    Full Text Available Economic order quantity model and production quantity model assume that production processes are error free. However, variations exist in processes which result in imperfection particularly in high machining environments. Processes variations result in nonconformities that increase quality costs in the form of rework, rejects and quality control techniques implementations to ensure quality product delivery. This paper is an attempt towards development of inventory model which incorporate inspection, rework, and rejection (IRR quality costs in optimum lot size calculation focusing work in process inventory. Mathematical model is derived for optimum lot size based on minimum average cost function using analytical approach. This new developed model (GTOQIRR assume an imperfect production environment. Numerical examples are used to visualize the significant effect of quality cost in the proposed model in comparison to the previously developed models. The proposed model is highly recommendable for quality based high machining manufacturing environments considering work in process inventories.

  11. A joint lot-sizing and marketing model with reworks, scraps and imperfect products

    Directory of Open Access Journals (Sweden)

    Mohsen Fathollah Bayati

    2011-04-01

    Full Text Available In this paper, we establish an economic production quantity (EPQ based inventory model by considering various types of non-perfect products .We classify products in four groups of perfect, imperfect, defective but reworkable and non-reworkable defective items. The demand is a power function of price and marketing expenditure and production unit cost is considered to be a function of lot size. The objective of this paper is to determine lot size, marketing expenditure, selling price, set up cost and inventory holding cost, simultaneously. The problem is modeled as a nonlinear posynomial geometric programming and an optimal solution is derived. The implementation of the proposed method is demonstrated using a numerical example and the sensitivity analysis is also performed to study the behavior of the model.

  12. The first case of drug-dependent memory: the biblical Lot in Talmudic and Midrashic exegesis.

    Science.gov (United States)

    Schnall, Eliezer; Saperstein, Yair; Saperstein, Yona

    2013-01-01

    The literature on alcohol and alcoholism has long noted how the effects of alcohol are reported in early sources, including religious texts such as the Bible and Talmud. In that vein, we suggest that the Bible, as elucidated according to long-established rabbinic interpretation, contains the earliest recorded case of drug-dependent memory, in the account of Lot's alcohol-facilitated incestuous relationships with his daughters (Genesis 19:29-38). We posit that the Talmudic, Midrashic, and traditional rabbinic commentaries that support our reading of the Lot narrative convey keen understanding of the effects of alcohol on recall. These Jewish sources, written centuries ago, demonstrate insight into the nature of alcohol-influenced cognitive function, which was thought to have been unknown prior to contemporary times. PMID:23586543

  13. A software development for establishing optimal production lots and its application in academic and business environments

    Directory of Open Access Journals (Sweden)

    Javier Valencia Mendez

    2014-11-01

    Full Text Available The recent global economic downturn has increased an already perceived need in organizations for cost savings. To cope with such need, companies can opt for different strategies. This paper focuses on optimizing processes and, more specifically, determining the optimal lot production. To determine the optimal lot of a specific production process, a new software was developed that not only incorporates various productive and logistical elements in its calculations but also affords users a practical way to manage the large number of input parameters required to determine the optimal batch. The developed software has not only been validated by several companies, both Spanish and Mexican, who achieved significant savings, but also used as a teaching tool in universities with highly satisfactory results from the point of view of student learning. A special contribution of this work is that the developed tool can be sent to the interested reader free of charge upon request.

  14. Changing the values of parameters on lot size reorder point model

    Directory of Open Access Journals (Sweden)

    Chang Hung-Chi

    2003-01-01

    Full Text Available The Just-In-Time (JIT philosophy has received a great deal of attention. Several actions such as improving quality, reducing setup cost and shortening lead time have been recognized as effective ways to achieve the underlying goal of JIT. This paper considers the partial backorders, lot size reorder point inventory system with an imperfect production process. The objective is to simultaneously optimize the lot size, reorder point, process quality, setup cost and lead time, constrained on a service level. We assume the explicit distributional form of lead time demand is unknown but the mean and standard deviation are given. The minimax distribution free approach is utilized to solve the problem and a numerical example is provided to illustrate the results. .

  15. Inventory Lot-Sizing Problem with Supplier Selection under Storage Space and Budget Constraints

    Directory of Open Access Journals (Sweden)

    Chirawat Woarawichai

    2011-03-01

    Full Text Available In this paper, we consider a multi-period inventory lot-sizing problem with supplier selection under storage space and budget constraints. The objective of this research is to calculate the optimal inventory lot-sizing for each supplier and minimize the total inventory cost which includes joint purchase cost of the products, transaction cost for the suppliers, and holding cost for remaining inventory. It is assumed that demand of multiple products is known over a planning horizon. The problem is formulated as a mixed integer linear programming and is solved with optimization package like LINGO12. Finally, numerical example is provided to illustrate the solution procedure. The results determine what products to order in what quantities with which suppliers in which periods, in order to satisfy overall demand.

  16. A review of lot streaming in a flow shop environment with makespan criteria

    Directory of Open Access Journals (Sweden)

    Pedro Gómez-Gasquet

    2013-07-01

    Full Text Available Purpose: This paper reviews current literature and contributes a set of findings that capture the current state-of-the-art of the topic of lot streaming in a flow-shop. Design/methodology/approach: A literature review to capture, classify and summarize the main body of knowledge on lot streaming in a flow-shop with makespan criteria and, translate this into a form that is readily accessible to researchers and practitioners in the more mainstream production scheduling community. Findings and Originality/value: The existing knowledge base is somewhat fragmented. This is a relatively unexplored topic within mainstream operations management research and one which could provide rich opportunities for further exploration. Originality/value: This paper sets out to review current literature, from an advanced production scheduling perspective, and contributes a set of findings that capture the current state-of-the-art of this topic.

  17. LABORATORY SIMULATION OF POROUS ASPHALT PARKING LOT SYSTEM AND MIX DESIGN FOR STORM WATER MANAGEMENT

    OpenAIRE

    M.O. Hamzah; Z. F. M. JAAFAR; Ahmad, F

    2013-01-01

    Porous asphalt pavement was initially developed for the purpose of improving road safety, best candidate material for quiet pavement and to avoid aquaplaning and skidding in wet weather. However, from previous studies, porous asphalt is able to mitigate surface runoff. Porous asphalt parking lots with underlying reservoir course perform as additional temporary water storage matrix that enables reduction of flash flood. This paper elaborates the development of a new porous asphalt aggregate g...

  18. Bioactive properties of Mentha spicata L. infusions: a comparison between standard and reserve lots

    OpenAIRE

    Rita, Íngride; Pereira, Carla; Heleno, Sandrina A.; Ferreira, Isabel C.F.R.

    2015-01-01

    Mentha spicata L., commonly known as spearmint and belonging to the Lamiaceae family, is widely used as infusion due to its exquisite and outstanding flavour [1]. This medicinal and aromatic plant is also known for its antioxidant properties due to naturally occurring active compounds, such as phenolic compounds including flavonoids. [2] Recently, with the increased consumption of herbal infusions, several novel products are emerging and different lots with distinct composition...

  19. Antioxidant activity and nutritional value of Mentha spicata L.: a comparison between reserve and standard lots

    OpenAIRE

    Rita, Íngride; Heleno, Sandrina A.; Martins, Natália; Pereira, Carla; Barros, Lillian; Ferreira, Isabel C.F.R.

    2015-01-01

    Currently, the consumption of tea and herbal infiisions is increasing só much that its daily worldwide consumption is evaluated in more than three million cups. Therefore, in a competitive and sophisticated sector as the tea market, the innovation and development of new products is imperative (Hicks, 2009; Li et al., 2013). Nowadays, we have at our disposal a new range of emerging products, such as the designated "reserve lots" exclusively prepared by using the younger parts (a...

  20. APPLICATION OF LOT QUALITY ASSURANCE SAMPLING FOR ASSESSING DISEASE CONTROL PROGRAMMES - EXAMINATION OF SOME METHODOLOGICAL ISSUES

    OpenAIRE

    T. R. RAMESH RAO

    2011-01-01

    Lot Quality Assurance Sampling (LQAS), a statistical tool in industrial setup, has been in use since 1980 for monitoring and evaluation of programs on disease control / immunization status among children / health workers performance in health system. While conducting LQAS in the field, there are occasions, even after due care of design, there are practical and methodological issues to be addressed before it is recommended for implementation and intervention. LQAS is applied under the assumpti...

  1. Reduction of in-lot overlay variation with integrated metrology, and a holistic control strategy

    Science.gov (United States)

    Lee, Hong-Goo; Han, Sang-Jun; Ma, Won-Kwang; Kim, Young-Sik; Kwak, Noh-Jung; Böcker, Paul; Deckers, David; Kou, Weitian; Kupers, Michiel; Ryan, Kevin; McNamara, Elliott; Kim, Gwang-Gon; Sun, Kyu-Tae; Lim, Young-Wan; Byun, Jin-Moo; Suh, Jung-Joon

    2015-10-01

    As DRAM semiconductor manufacturing approaches high volume for 1x nm nodes with immersion lithography, an increased emphasis is being placed on reducing the influence of the systematic wafer-level contribution to the on-product overlay budget. The cost of the needed metrology has hitherto been challenging. However, it will be shown that the availability of fast, accurate diffraction based metrology integrated within the Lithography cluster can enable cost-effective solutions. Together with applications software we will use any relevant context information to optimize control of all exposure-tool actuators during lot processing, to deliver the needed on-product performance. Current process corrections typically are done based on feedback per lot and per exposure chuck. Wafers exposed on the same chuck, belonging to the same lot get exactly the same process corrections. In current HVM processing however, an important contribution to the wafer variation is the differences in processing of the individual wafers. These differences can be related to variations in the usage of the processing tools (e.g. different etch chambers). An extension of the process corrections from chuck-based to process-context based can help in reducing the systematic wafer-level variation. With Integrated Metrology the sampling of wafers through the lot can be adjusted to make sure all different processing-contexts are covered in the measurements. Finally, the impact on Litho process cycle time of the total metrology effort required to enable these performance improvements, will be evaluated, and a proposal will be made on the optimum strategy to enable high-volume manufacturing.

  2. Balancing and lot-sizing mixed-model lines in the footwear industry

    OpenAIRE

    Sadeghi, Parisa

    2015-01-01

    This report describes the full research proposal for the project \\Balancing and lot-sizing mixed-model lines in the footwear industry", to be developed as part of the master program in Engenharia Electrotécnica e de Computadores - Sistemas de Planeamento Industrial of the Instituto Superior de Engenharia do Porto. The Portuguese footwear industry is undergoing a period of great development and innovation. The numbers speak for themselves, Portugal footwear exported 71 million pairs of shoes t...

  3. Strength testing of production grade H-451 graphite; lots 472, 478, and 482

    International Nuclear Information System (INIS)

    Ninety-eight production logs of H-451 graphite, from three separate extrusion lots, were sampled for tensile testing. Eight replicate axial specimens from the midlength center and four replicate radial specimens from the end center of each log were tested. The axial strengths (average value 12.7 MPa) showed wide lot-to-lot and log-to-log variations, while the radial strengths (average value 15.8 MPa) were more uniform. Statistically based acceptance criteria which could be used for assigning a log to a minimum strength category were derived for two alternative definitions of ''minimum'' strength. The first definition would require 90 percent of the material at the midlength center of the log to exceed the specified minimum strength, with 90 percent confidence (90/90); the second, more stringent, definition would require 99 percent of the material to exceed the specified minimum, with 95 percent confidence (99/95). If three minimum strength categories are assumed, with category A requiring a minimum strength of 10.3 MPa, category B requiring 8.3 MPa, and category C requiring 5.5 MPa, use of the 90/90 definition of minimum strength would cause the rejection of two logs. Use of the 99/95 definition of minimum strength would increase the number of rejected logs to 18; however, this would include only 2 out of the 56 logs in the best extrusion lot. Decreasing the number of tests per log from eight to four would cause only small differences in the yields of logs accepted in each category

  4. Estimating aflatoxin in farmers' stock peanut lots by measuring aflatoxin in various peanut-grade components.

    Science.gov (United States)

    Whitaker, T B; Hagler, W M; Giesbrecht, F G; Dorner, J W; Dowell, F E; Cole, R J

    1998-01-01

    Five, 2 kg test samples were taken from each of 120 farmers' stock peanut lots contaminated with aflatoxin. Kernels from each 2 kg sample were divided into the following grade components: sound mature kernels plus sound splits (SMKSS), other kernels (OK), loose shelled kernels (LSK), and damaged kernels (DAM). Kernel mass, aflatoxin mass, and aflatoxin concentration were measured for each of the 2400 component samples. For 120 lots tested, average aflatoxin concentrations in SMKSS, OK, LSK, and DAM components were 235, 2543, 11,775, and 69,775 ng/g, respectively. Aflatoxins in SMKSS, OK, LSK, and DAM components represented 6.9, 7.9, 33.3, and 51.9% of the total aflatoxin mass, respectively. Cumulatively, 3 aflatoxin risk components--OK, LSK, and DAM--accounted for 93.1% of total aflatoxin, but only 18.4% percent of test sample mass. Correlation analysis suggests that the most accurate predictor of aflatoxin concentration in the lot is the cumulative aflatoxin mass in the high 3 risk components OK + LSK + DAM (correlation coefficient, r = 0.996). If the aflatoxin in the combined OK + LSK + DAM components is expressed in concentration units, r decreases to 0.939. Linear regression equations relating aflatoxin in OK + LSK + DAM to aflatoxin concentration in the lot were developed. The cumulative aflatoxin in the OK + LSK + DAM components was not an accurate predictor (r = 0.539) of aflatoxin in the SMKSS component. Statistical analyses of 3 other data sets published previously yielded similar results. PMID:9477563

  5. L'ichnospace de Luzech (Lot, France) : un exemple de valorisation d'empreintes de pas

    OpenAIRE

    Lange-Badré, Brigitte

    2013-01-01

    The Ichnospace is a specific exhibition dedicated to traces and tracks left by recent and fossil animals on ground. The Ichnospace is located at Luzech, a little town with a long historic past, near Cahors (about 17 km W) in the valley of the river Lot. Every living being leaves traces of its activities (habitat, locomotion, diet, etc.) in its environment. These traces are the signing of the individual and they may be preserved and fossilised in geological time. They provide information about...

  6. Inter- and Intra-Manufacturer Variability in Pharmaceutical Grades and Lots of Xanthan Gum

    OpenAIRE

    Thacker, Ankur; Fu, Shao; Boni, Riccardo L.; Block, Lawrence H.

    2010-01-01

    A pharmaceutical formulation typically contains one or more excipients in addition to the active pharmaceutical ingredient(s). Though excipients have been considered inert components of a formulation, variability in their properties has been shown to affect the performance of drug dosage forms and delivery systems. This study investigates the inter- and intra-manufacturer variability among different NF grades and lots of xanthan gum made by two manufacturers. As many formulators rely on compe...

  7. A Rain Gauge System using a Capacitance Sensor

    Directory of Open Access Journals (Sweden)

    Worawat Sa-Ngiamvibool

    2013-08-01

    Full Text Available This paper proposes a rain gauge system using a coaxial capacitance sensor. The proposed system consists of a high-pass filter, a coaxial capacitance sensor, SMS module, a microcontroller and a smartphone. The sensor capacitance is proportional to the rainfall levels. It is converted into voltage signal. The corresponding voltage signal is sent to the microcontroller for converting the signal levels to the rainfall levels in millimetres. The microcontroller sends the rainfall levels to the SMS module that then sends the rainfall level data to show on the display screen of the smartphone. The experimentalresults showed that the proposed prototype can provide the correct data compared to the traditional system.

  8. A microcontroller-based interface circuit for lossy capacitive sensors

    International Nuclear Information System (INIS)

    This paper introduces and analyses a low-cost microcontroller-based interface circuit for lossy capacitive sensors, i.e. sensors whose parasitic conductance (Gx) is not negligible. Such a circuit relies on a previous circuit also proposed by the authors, in which the sensor is directly connected to a microcontroller without using either a signal conditioner or an analogue-to-digital converter in the signal path. The novel circuit uses the same hardware, but it performs an additional measurement and executes a new calibration technique. As a result, the sensitivity of the circuit to Gx decreases significantly (a factor higher than ten), but not completely due to the input capacitances of the port pins of the microcontroller. Experimental results show a relative error in the capacitance measurement below 1% for Gx x) shows the effectiveness of the circuit

  9. New low-cost MEMS capacitive pressure sensor concept

    Science.gov (United States)

    Wang, Yun; Cheung, Kin P.; Sheng, Kuang; Pai, Chien-Shing

    2005-01-01

    Capacitive pressure sensors based on surface or bulk MEMS technology have many attributes that make them highly desirable for many applications. The biggest technical challenge of capacitive pressure sensor technology is the creation of a reference cavity. It dictates the packaging approach and therefore the cost of the sensor. In this paper we introduce a new design of capacitive pressure sensor that takes advantage of a novel new wafer level packaging technology - A thin-film sealing technology that allows independent pressure control from high vacuum to high pressure. The new technology seals the vacuum cavity formed by standard surface micro machining technology by a brief melting of a metal layer using a pulsed laser. The ability to form reference vacuum cavity without the need for fusing or bonding with another structure allows the design to be simplified, leading to low cost and high yield.

  10. Class D audio amplifiers for high voltage capacitive transducers

    DEFF Research Database (Denmark)

    Nielsen, Dennis

    implications of driving the non-linear transducer of the DEAP. 2-level modulated high voltage amplifiers driving the capacitive load of the DEAP transducer are addressed in chapter 4. An amplifier with fourth order output filter and full-state self-oscillating hysteresis based control loop is proposed...... on a silicone film. As a consequence a capacitive transducer emerges, which can be shaped into the loudspeaker membrane itself, rolled up into a transducer driving a membrane or being part of an active suspension system for the membrane. In order to document the full potential of the DEAP transducer, suitable....... Due to the similarities between the electrostatic loudspeaker and the DEAP transducer, the state-of-the-art has a special focus on amplifiers for electrostatic loudspeakers. Amplifiers for other type of capacitive transducers like piezoelectric ones are also considered. Finally the current state...

  11. Capacitive Micromachined Ultrasonic Transducers (CMUTs for Underwater Imaging Applications

    Directory of Open Access Journals (Sweden)

    Jinlong Song

    2015-09-01

    Full Text Available A capacitive micromachined ultrasonic transducer structure for use in underwater imaging is designed, fabricated and tested in this paper. In this structure, a silicon dioxide insulation layer is inserted between the top electrodes and the vibration membrane to prevent ohmic contact. The capacitance-voltage (C-V characteristic curve shows that the transducer offers suitable levels of hysteresis and repeatability performance. The −6 dB center frequency is 540 kHz and the transducer has a bandwidth of 840 kHz for a relative bandwidth of 155%. Underwater pressure of 143.43 Pa is achieved 1 m away from the capacitive micromachined ultrasonic transducer under 20  excitation. Two-dimensional underwater ultrasonic imaging, which is able to prove that a rectangular object is present underwater, is achieved. The results presented here indicate that our work will be highly beneficial for the establishment of an underwater ultrasonic imaging system.

  12. Effect of surfactants on capacitance properties of carbon electrodes

    International Nuclear Information System (INIS)

    Effect of surfactants present in alkaline solutions on the capacitance of carbon electrodes has been studied. Different types of surfactants, i.e., sodium and lithium dodecyl sulphate as anionic surfactants, tetrapropylammonium bromide and iodide as cationic surfactants and polymer of polyethylene glycol and p-t-octylophenol (commercially called Triton® X-100) as non-ionic one have been selected for this target. Concentration of these electrolyte additives was 0.005 mol L−1. Decreasing the surface tension in the electrode/electrolyte interface allows better penetration of electrolyte into the pores. However, surfactants played a different role depending on the electrode polarity. Detailed analysis of capacitance versus current load, frequency dependence as well as self-discharge, cyclability and behaviour in wider voltage range proved especially a profitable effect of Triton® X-100 on capacitor operating in alkaline solution. Influence of surfactant concentration on capacitance properties was also investigated.

  13. 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...... 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...... have been obtained. Temperature characterization was performed and showed a decrease in capacitance as the temperature increases. The maximum output variation, relative to room temperature, has been found to be 0.15 %/°C at 80 °C, while an almost constant variation of 0.044 %/°C is achieved if working...

  14. Capacitive measurement of mercury column heights in capillaries.

    Science.gov (United States)

    Frey, Sarah; Richert, Ranko

    2010-03-01

    The detection of changes in volume, e.g., in expansivity or aging measurements, are often translated into mercury column height within a glass capillary. We propose a capacitive technique for measuring the meniscus position using a cylindrical capacitor with mercury as the inner electrode, the capillary material as the dielectric, and a metal coat covering the outside surface of the capillary as the second electrode. The measured capacitance changes linearly with meniscus height, as long as the top mercury level remains within the range of the outer electrode. With the demonstrated noise level of 48 nm for our preliminary setup, meniscus height changes beyond 100 nm can be observed via the capacitance. PMID:20370203

  15. Wavelet approach to artifact noise removal from Capacitive coupled Electrocardiograph.

    Science.gov (United States)

    Lee, Seung Min; Kim, Ko Keun; Park, Kwang Suk

    2008-01-01

    Capacitive coupled Electrocardiography (ECG) is introduced as non-invasive measurement technology for ubiquitous health care and appliance are spread out widely. Although it has many merits, however, capacitive coupled ECG is very weak for motion artifacts for its non-skin-contact property. There are many studies for artifact problems which treats all artifact signals below 0.8Hz. In our capacitive coupled ECG measurement system, artifacts exist not only below 0.8Hz but also over than 10Hz. Therefore, artifact noise removal algorithm using wavelet method is tested to reject artifact-wandered signal from measured signals. It is observed that using power calculation each decimation step, artifact-wandered signal is removed as low frequency artifacts as high frequency artifacts. Although some original ECG signal is removed with artifact signal, we could level the signal quality for long term measure which shows the best quality ECG signals as we can get. PMID:19163323

  16. 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.

  17. 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.

  18. 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.

  19. Superconducting flux qubit capacitively coupled to an LC resonator

    International Nuclear Information System (INIS)

    We study the system where a superconducting flux qubit is capacitively coupled to an LC resonator. In three devices with different coupling capacitance, the magnitude of the dispersive shift is enhanced by the third level of the qubit and quantitatively agrees with the theory. We show by numerical calculation that the capacitive coupling plays an essential role for the enhancement in the dispersive shift. We investigate the coherence properties in two of these devices, which are in the strong-dispersive regime, and show that the qubit energy relaxation is currently not limited by the coupling. We also observe the discrete ac-Stark effect, a hallmark of the strong-dispersive regime, in accordance with the theory. (paper)

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

    DEFF Research Database (Denmark)

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

    2013-01-01

    in a number of applications. In this paper, the discharging energy efficiency definition is introduced. The proposed converter has been experimentally tested with the film capacitive load and the DEAP actuator, and the experimental results are shown together with the efficiency measurements.......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...

  1. A genetic algorithm-based approach to flexible flow-line scheduling with variable lot sizes.

    Science.gov (United States)

    Lee, I; Sikora, R; Shaw, M J

    1997-01-01

    Genetic algorithms (GAs) have been used widely for such combinatorial optimization problems as the traveling salesman problem (TSP), the quadratic assignment problem (QAP), and job shop scheduling. In all of these problems there is usually a well defined representation which GA's use to solve the problem. We present a novel approach for solving two related problems-lot sizing and sequencing-concurrently using GAs. The essence of our approach lies in the concept of using a unified representation for the information about both the lot sizes and the sequence and enabling GAs to evolve the chromosome by replacing primitive genes with good building blocks. In addition, a simulated annealing procedure is incorporated to further improve the performance. We evaluate the performance of applying the above approach to flexible flow line scheduling with variable lot sizes for an actual manufacturing facility, comparing it to such alternative approaches as pair wise exchange improvement, tabu search, and simulated annealing procedures. The results show the efficacy of this approach for flexible flow line scheduling. PMID:18255838

  2. Sources of uncertainty in the quantification of genetically modified oilseed rape contamination in seed lots.

    Science.gov (United States)

    Begg, Graham S; Cullen, Danny W; Iannetta, Pietro P M; Squire, Geoff R

    2007-02-01

    Testing of seed and grain lots is essential in the enforcement of GM labelling legislation and needs reliable procedures for which associated errors have been identified and minimised. In this paper we consider the testing of oilseed rape seed lots obtained from the harvest of a non-GM crop known to be contaminated by volunteer plants from a GM herbicide tolerant variety. The objective was to identify and quantify the error associated with the testing of these lots from the initial sampling to completion of the real-time PCR assay with which the level of GM contamination was quantified. The results showed that, under the controlled conditions of a single laboratory, the error associated with the real-time PCR assay to be negligible in comparison with sampling error, which was exacerbated by heterogeneity in the distribution of GM seeds, most notably at a small scale, i.e. 25 cm3. Sampling error was reduced by one to two thirds on the application of appropriate homogenisation procedures. PMID:17106767

  3. LABORATORY SIMULATION OF POROUS ASPHALT PARKING LOT SYSTEM AND MIX DESIGN FOR STORM WATER MANAGEMENT

    Directory of Open Access Journals (Sweden)

    M. O. HAMZAH

    2013-04-01

    Full Text Available Porous asphalt pavement was initially developed for the purpose of improving road safety, best candidate material for quiet pavement and to avoid aquaplaning and skidding in wet weather. However, from previous studies, porous asphalt is able to mitigate surface runoff. Porous asphalt parking lots with underlying reservoir course perform as additional temporary water storage matrix that enables reduction of flash flood. This paper elaborates the development of a new porous asphalt aggregate grading design for storm water mitigation using the Nominal Maximum Aggregate Size (NMAS 20 mm. The properties of the mixes were quantified and evaluated in terms of air voids, permeability, abrasion loss and indirect tensile strength. It was found that the proposed gradation has the best permeability and Indirect Tensile Strength (ITS values when compacted at 50 blows per face with a standard Marshal compactor. The porous asphalt slab was prepared using a slab compactor to simulate porous parking lot paving at site. The porous asphalt slab was finally placed inside a locally fabricated water flow simulator to simulate a porous asphalt pavement system for parking lots.

  4. Contactless vector network analysis using diversity calibration with capacitive and inductive coupled probes

    Directory of Open Access Journals (Sweden)

    T. Zelder

    2007-06-01

    Full Text Available Contactless vector network analysis based on a diversity calibration is investigated for the measurement of embedded devices in planar circuits. Conventional contactless measurement systems based on two probes for each measurement port have the disadvantage that the signal-to-noise system dynamics strongly depends on the distance between the contactless probes.

    In order to avoid a decrease in system dynamics a diversity based measurement system is presented. The measurement setup uses one inductive and two capacitive probes. As an inductive probe a half magnetic loop in combination with a broadband balun is introduced. In order to eliminate systematic errors from the measurement results a diversity calibration algorithm is presented. Simulation and measurement results for a one-port configuration are shown.

  5. Spectroelectrochemical Signatures of Capacitive Charging and Ion Insertion in Doped Anatase Titania Nanocrystals.

    Science.gov (United States)

    Dahlman, Clayton J; Tan, Yizheng; Marcus, Matthew A; Milliron, Delia J

    2015-07-22

    Solution-processed films of colloidal aliovalent niobium-doped anatase TiO2 nanocrystals exhibit modulation of optical transmittance in two spectral regions-near-infrared (NIR) and visible light-as they undergo progressive and reversible charging in an electrochemical cell. The Nb-TiO2 nanocrystal film supports a localized surface plasmon resonance in the NIR, which can be dynamically modulated via capacitive charging. When the nanocrystals are charged by insertion of lithium ions, inducing a well-known structural phase transition of the anatase lattice, strong modulation of visible transmittance is observed. Based on X-ray absorption near-edge spectroscopy, the conduction electrons localize only upon lithium ion insertion, thus rationalizing the two modes of optical switching observed in a single material. These multimodal electrochromic properties show promise for application in dynamic optical filters or smart windows. PMID:26154107

  6. 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.

  7. 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%.

  8. Scanning Capacitance Microscopy in the Quantum Hall Regime

    OpenAIRE

    Suddards, Matthew Edmund

    2007-01-01

    This thesis discusses the development of a novel scanning capacitance microscope (SCM) that enables the investigation of the local capacitance and conductivity of surfaces and near-surface nanostructures at cryogenic temperatures and high magnetic fields. Simultaneous atomic force microscopy (AFM) and SCM measurements can be made at a temperature of 1.5K and a magnetic field of 12T. The AFM/SCM sensor is based on a quartz-tuning fork with an etched metal tip. SCM measurements are made us...

  9. 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.

  10. Optimizing the Materials Response in Humidity Capacitive Sensors

    OpenAIRE

    Elham Noroozi Afshar; Hossein Golnabi; Nima E. Gorji

    2015-01-01

    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 cylin...

  11. Characterisation of a highly symmetrical miniature capacitive triaxial accelerometer

    OpenAIRE

    Lotters, J.C.; Olthuis, W.; Veltink, P.H.; Bergveld, P.

    1997-01-01

    A highly symmetrical cubic capacitive triaxial accelerometer for biomedical applications has been designed, realised and tested. The sensors are available in two outer dimensions, namely 2×2×2 and 5×5×5 mm3. The devices are mounted on a standard IC package for easy testing. Features of the sensor are a highly symmetrical cubic structure, capacitive coupling of the high frequency input voltage to the seismic mass and the use of the polymers polydimethylsiloxane (PDMS) as spring material betwee...

  12. 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.

  13. 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.

  14. Double-driven shield capacitive type proximity sensor

    Science.gov (United States)

    Vranish, John M. (Inventor)

    1993-01-01

    A capacity type proximity sensor comprised of a capacitance type sensor, a capacitance type reference, and two independent and mutually opposing driven shields respectively adjacent to the sensor and reference and which are coupled in an electrical bridge circuit configuration and driven by a single frequency crystal controlled oscillator is presented. The bridge circuit additionally includes a pair of fixed electrical impedance elements which form adjacent arms of the bridge and which comprise either a pair of precision resistances or capacitors. Detection of bridge unbalance provides an indication of the mutual proximity between an object and the sensor. Drift compensation is also utilized to improve performance and thus increase sensor range and sensitivity.

  15. [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. PMID:2486981

  16. Development of Image Reconstruction Algorithms in electrical Capacitance Tomography

    International Nuclear Information System (INIS)

    The Electrical Capacitance Tomography (ECT) has not obtained a good development in order to be used at industrial level. That is due first to difficulties in the measurement of very little capacitances (in the range of femto farads) and second to the problem of reconstruction on- line of the images. This problem is due also to the small numbers of electrodes (maximum 16), that made the usual algorithms of reconstruction has many errors. In this work it is described a new purely geometrical method that could be used for this purpose. (Author) 4 refs

  17. Differential capacitance probe for process control involving aqueous dielectric fluids

    Science.gov (United States)

    Svoboda, John M.; Morrison, John L.

    2002-10-08

    A differential capacitance probe device for process control involving aqueous dielectric fluids is disclosed. The device contains a pair of matched capacitor probes configured in parallel, one immersed in a sealed container of reference fluid, and the other immersed in the process fluid. The sealed container holding the reference fluid is also immersed in the process fluid, hence both probes are operated at the same temperature. Signal conditioning measures the difference in capacitance between the reference probe and the process probe. The resulting signal is a control error signal that can be used to control the process.

  18. A low-noise/low-power preamplifier for capacitive microphones

    OpenAIRE

    Fürst, Claus Erdmann

    1996-01-01

    A design for a microphone preamplifier for application in hearing aids is presented. The amplifier operates at a supply of 1-1.5 V, the current drain is 40 μA. The maximum sound level allowed is more than 120 dB SPL (Sound Pressure Level), with a typical noise level of 25 dB(A) SPL (A-weighted). The amplifier is optimized for a capacitive microphone with a capacitance of 1.2 pF. The amplifier is fully integrated in a 0.7 μm n-well CMOS technology. Design details concerning noise performance a...

  19. 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.

  20. A low-noise/low-power preamplifier for capacitive microphones

    DEFF Research Database (Denmark)

    Fürst, Claus Erdmann

    1996-01-01

    A design for a microphone preamplifier for application in hearing aids is presented. The amplifier operates at a supply of 1-1.5 V, the current drain is 40 μA. The maximum sound level allowed is more than 120 dB SPL (Sound Pressure Level), with a typical noise level of 25 dB(A) SPL (A-weighted). ......-weighted). The amplifier is optimized for a capacitive microphone with a capacitance of 1.2 pF. The amplifier is fully integrated in a 0.7 μm n-well CMOS technology. Design details concerning noise performance are analytically described...

  1. A multi-phase algorithm for a joint lot-sizing and pricing problem with stochastic demands

    DEFF Research Database (Denmark)

    Jenny Li, Hongyan; Thorstenson, Anders

    2014-01-01

    Stochastic lot-sizing problems have been addressed quite extensively, but relatively few studies also consider marketing factors, such as pricing. In this paper, we address a joint stochastic lot-sizing and pricing problem with capacity constraints and backlogging for a firm that produces a single...... that the multi-phase heuristic algorithm solves the example problems effectively....

  2. Three Permeable Pavements Performances for Priority Metal Pollutants and Metals Associated with Deicing Chemicals from Edison Parking Lot, NJ

    Science.gov (United States)

    The U.S. Environmental Protection Agency constructed a 4000-m2 parking lot in Edison, New Jersey in 2009. The parking lot is surfaced with three permeable pavements [permeable interlocking concrete pavers (PICP), pervious concrete (PC), and porous asphalt (PA)]. Samples of each p...

  3. Three Permeable Pavements Performances for Priority Metal Pollutants and Metals associated with Deicing Chemicals from Edison Parking Lot, NJ - abstract

    Science.gov (United States)

    The U.S. Environmental Protection Agency constructed a 4000-m2 parking lot in Edison, New Jersey in 2009. The parking lot is surfaced with three permeable pavements [permeable interlocking concrete pavers (PICP), pervious concrete (PC), and porous asphalt (PA)]. Samples of each p...

  4. Advanced high-k dielectric amorphous LaGdO3 based high density metal-insulator-metal capacitors with sub-nanometer capacitance equivalent thickness

    Science.gov (United States)

    Pavunny, S. P.; Misra, P.; Scott, J. F.; Katiyar, R. S.

    2013-06-01

    Planar metal-insulator-metal (MIM) mono-dielectric layer stacks were fabricated using pulsed laser deposited thin films of high-k dielectric LaGdO3. These stacks showed high capacitance density ˜43.5 fF/μm2 with sub-nanometer capacitance equivalent thicknesses of ˜0.66 nm, large breakdown field of ˜6 MV/cm, greater energy storage density of ˜40 J/cm3, smaller voltage coefficient of capacitance, and lower dependence of it on layer thickness α ∝ d-1 and frequency. All these features make LaGdO3 a material of interest for next generation MIM structures for radio frequency, analog/mixed-signal, and dynamic random access memory applications.

  5. An 11-bit 22-MS/s 0.6 mW SAR ADC with parasitic capacitance compensation

    International Nuclear Information System (INIS)

    This paper presents an 11-bit 22-MS/s 0.6-mW successive approximation register (SAR) analog-to-digital converter (ADC) using SMIC 65-nm low leakage (LL) CMOS technology with a 1.2 V supply voltage. To reduce the total capacitance and core area the split capacitor architecture is adopted. But in high resolution ADCs the parasitic capacitance in the LSB-side would decrease the linearity of the ADC and it is hard to calibrate. This paper proposes a parasitic capacitance compensation technique to cancel the effect with no calibration circuits. Moreover, dynamic circuits are used to minimize the switching power of the digital logic and also can reduce the latency time. The prototype chip realized an 11-bit SAR ADC fabricated in SMIC 65-nm CMOS technology with a core area of 300 × 200 μm2. It shows a sampling rate of 22 MS/s and low power dissipation of 0.6 mW at a 1.2 V supply voltage. At low input frequency the signal-to-noise-and-distortion ratio (SNDR) is 59.3 dB and the spurious-free dynamic range is 72.2 dB. The peak figure-of-merit is 36.4 fJ/conversion-step. (semiconductor integrated circuits)

  6. The use of knowledge-based Genetic Algorithm for starting time optimisation in a lot-bucket MRP

    Science.gov (United States)

    Ridwan, Muhammad; Purnomo, Andi

    2016-01-01

    In production planning, Material Requirement Planning (MRP) is usually developed based on time-bucket system, a period in the MRP is representing the time and usually weekly. MRP has been successfully implemented in Make To Stock (MTS) manufacturing, where production activity must be started before customer demand is received. However, to be implemented successfully in Make To Order (MTO) manufacturing, a modification is required on the conventional MRP in order to make it in line with the real situation. In MTO manufacturing, delivery schedule to the customers is defined strictly and must be fulfilled in order to increase customer satisfaction. On the other hand, company prefers to keep constant number of workers, hence production lot size should be constant as well. Since a bucket in conventional MRP system is representing time and usually weekly, hence, strict delivery schedule could not be accommodated. Fortunately, there is a modified time-bucket MRP system, called as lot-bucket MRP system that proposed by Casimir in 1999. In the lot-bucket MRP system, a bucket is representing a lot, and the lot size is preferably constant. The time to finish every lot could be varying depends on due date of lot. Starting time of a lot must be determined so that every lot has reasonable production time. So far there is no formal method to determine optimum starting time in the lot-bucket MRP system. Trial and error process usually used for it but some time, it causes several lots have very short production time and the lot-bucket MRP would be infeasible to be executed. This paper presents the use of Genetic Algorithm (GA) for optimisation of starting time in a lot-bucket MRP system. Even though GA is well known as powerful searching algorithm, however, improvement is still required in order to increase possibility of GA in finding optimum solution in shorter time. A knowledge-based system has been embedded in the proposed GA as the improvement effort, and it is proven that the

  7. Capacitated max -Batching with Interval Graph Compatibilities

    Science.gov (United States)

    Nonner, Tim

    We consider the problem of partitioning interval graphs into cliques of bounded size. Each interval has a weight, and the weight of a clique is the maximum weight of any interval in the clique. This natural graph problem can be interpreted as a batch scheduling problem. Solving a long-standing open problem, we show NP-hardness, even if the bound on the clique sizes is constant. Moreover, we give a PTAS based on a novel dynamic programming technique for this case.

  8. Dynamics

    CERN Document Server

    Goodman, Lawrence E

    2001-01-01

    Beginning text presents complete theoretical treatment of mechanical model systems and deals with technological applications. Topics include introduction to calculus of vectors, particle motion, dynamics of particle systems and plane rigid bodies, technical applications in plane motions, theory of mechanical vibrations, and more. Exercises and answers appear in each chapter.

  9. A silicon MEMS structure for characterization of femto-farad-level capacitive sensors with lock-in architecture

    OpenAIRE

    Wei, J; Chen, Z.L.; Liu, Z. W.; Sarro, P. M.

    2010-01-01

    This paper presents a silicon MEMS capacitive structure to investigate a test methodology for fF-level capacitive sensors’ measurement. The device mimics a capacitive sensor with a changing intermediate layer between the electrodes. A single mask bulk micromachining process is used to fabricate the device, which has a nominal capacitance of 1.2 fF. A high performance measurement setup based on lock-in principle is developed to detect the capacitance variation. The maximum capacitance variatio...

  10. Customer Service Competition in Capacitated Systems

    OpenAIRE

    Joseph Hall; Evan Porteus

    2000-01-01

    We investigate a simple dynamic model of firm behavior in which firms compete by investing in capacity that is used to provide a good or service to their customers. There is a fixed total market of customers whose demands for the good or service are random and who divide their patronage between the firms in each period. Periodically, the market shares of the two firms can change based on the realized level of customer service provided in the prior period. We assume that the expected level of ...

  11. 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.

  12. 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...

  13. 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 of...

  14. Multilevel inverter based class D audio amplifier for capacitive transducers

    DEFF Research Database (Denmark)

    Nielsen, Dennis; Knott, Arnold; Andersen, Michael A. E.

    2014-01-01

    The reduced semiconductor voltage stress makes the multilevel inverters especially interesting, when driving capacitive transducers for audio applications. A ± 300 V flying capacitor class D audio amplifier driving a 100 nF load in the midrange region of 0.1-3.5 kHz with Total Harmonic Distortion...

  15. 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

  16. FPGA Based Low Power ROM Design Using Capacitance Scaling

    DEFF Research Database (Denmark)

    Bansal, Meenakshi; Bansal, Neha; Saini, Rishita;

    2015-01-01

    An ideal capacitor will not dissipate any power, but a real capacitor wil l have some power dissipation. In this work, we are going to design capacitance scaling based low power ROM design. In order to test the compatibility of this ROM design with latest i7 Processor, we are operating this ROM...

  17. 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.  

  18. Effect of parasitic capacitance on dc SQUID performance

    International Nuclear Information System (INIS)

    This paper reports on the effect of parasitic capacitance Cp on dc SQUID characteristics and noise performance studied using a test structure consisting of 11 identical SQUID washers with Nb films of various widths covering the slit. The measured IV characteristics are in good agreement with simulations based on a simple lumped circuit model

  19. 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.

  20. High bandwidth on-chip capacitive tuning of microtoroid resonators.

    Science.gov (United States)

    Baker, Christopher G; Bekker, Christiaan; McAuslan, David L; Sheridan, Eoin; Bowen, Warwick P

    2016-09-01

    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. PMID:27607646

  1. A High-Precision Capacitive Sensor System for Displacement Measurements

    NARCIS (Netherlands)

    Yang, R.

    2015-01-01

    This thesis presents the theory, design and qualification of a precision capacitive sensor system for displacement measurement that require high resolution, high precision and simultaneously, low power consumption. The challenge to achieve the required performance has been taken care at both mechani

  2. Reconfigurable Prototyping Microfluidic Platform for DEP Manipulation and Capacitive Sensing.

    Science.gov (United States)

    Miled, Amine; Auclair, Benoit; Srasra, Anis; Sawan, Mohamad

    2015-04-01

    In this paper, we present a new rapid prototyping platform dedicated to dielectrophoretic microfluidic manipulation and capacitive cell sensing. The proposed platform offers a reconfigurable design including 4 independently programmable output channels to be distributed across 64 electrodes. Although its range of frequency covers up to 3.4 MHz, signal amplitude accuracy ( +/-10%) was demonstrated for frequencies up to 1 MHz and channel-to-channel phase shift setting was stable up to 1.5 MHz. A test of maximum resistive load showed a 10% attenuation of a 12 V peak-to-peak signal with a 22 Ω load. The platform has an advanced capacitive sensor to measure capacitance variation between in-channel electrodes with a sampling frequency up to 5 kH z. Experimental data of capacitive sensor showed a sensitivity of 100 fF. The sensor can be extended to 4 parallel measurements with lower frequency. We also present a new assembly technique for reusable microfluidic chip based on anisotropic adhesive conductive film, epoxy and PDMS. The proposed platform provides a wide range of control signals depending on the type of manipulation as sine, rectangular or square wave. The frequency range is extendible up to 3.4 MHz, in addition to a programmable phase shift circuit with a minimum phase step of 3.6(°) for each signal. PMID:25879968

  3. 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

  4. Capacitive sensor probe to assess frying oil degradation

    Directory of Open Access Journals (Sweden)

    Alfadhl Yahya Khaled

    2015-09-01

    Full Text Available The repeated usage of frying oil has been proven hazardous due to the degradation process by chemical reactions that lead to changes in the quality of the oil. Currently, the degree of frying oil degradation is indicated by the percentage of its total polar compounds (TPC. In this study, a capacitive sensor was designed to assess frying oil degradation at several heating time intervals by measuring changes on its electrical capacitance. The sensor was designed using interdigitated electrode structure. A total of 30 samples of 130 ml palm oil were heated at 180 °C up to 30 h. For each one hour interval, one sample was moved out from the laboratory oven. The electrical capacitance, total polar compound (TPC and viscosity of the samples were measured for analysis. Preliminary results demonstrated significant correlation between oil electrical capacitance with TPC and viscosity with R2 ranged from 0.83 to 0.90. The designed sensor has good potential for simple and inexpensive way of determining frying oil quality.

  5. Correlated Coulomb drag in capacitively coupled quantum-dot structures

    DEFF Research Database (Denmark)

    Kaasbjerg, Kristen; Jauho, Antti-Pekka

    2016-01-01

    We study theoretically Coulomb drag in capacitively coupled quantum dots (CQDs) -- a biasdriven dot coupled to an unbiased dot where transport is due to Coulomb mediated energy transfer drag. To this end, we introduce a master-equation approach which accounts for higher-order tunneling (cotunneli...

  6. 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

  7. MEMS Very Low Capacitive Pressure Sensor Based on CMOS Process

    International Nuclear Information System (INIS)

    The CMOS standard process with advantage of simplicity in term of design and fabrication process compatibility has triggered the invention of MEMS very low capacitive pressure sensor, (MEMS-VLCPS). In this paper the development of the whole structure of MEMS-VLCPS that involves the design simulation, fabrication and testing is described. The novelty of this work lies in the design and fabrication process itself. A new technique in fabricating thin sensor membrane of VLCPS using seal-off techniques is also presented. The physical structure of the membrane consists of parallel plate. The top plate acts as the flexible electrode membrane and the bottom plate acts as the counter electrode membrane. Both plates are separated by absolute air gap with fixed end at both sides. As a result, it was found that the etch-opening holes of 0.8 μm and seal-off thickness of 4000 Angstrom gave the optimum sealing surface. The percentage of relative capacitance change is extracted from the reference capacitance measurement. Air gap thickness of 0.3 μm gives the highest percentage of PRCC showing that smaller air gap thickness provides a larger change in capacitance value. (author)

  8. Mesoporous carbon microspheres with high capacitive performances for supercapacitors

    International Nuclear Information System (INIS)

    Highlights: • Small mesopores-enriched porous carbon microspheres were easily synthesized. • Small mesopores offer high ion-accessible surface area and facilitated ion diffusion. • The porous carbon exhibited a high specific capacitance and a good power property. - Abstract: Novel small-mesopores-enriched porous carbon microspheres have been synthesized from carbonaceous polysaccharide microspheres, by using the associated lithium acetate treating and heat treating strategies. X-ray diffraction, scanning electron microscope, transmission electron microscopy and nitrogen adsorption-desorption techniques have been employed to investigate the as-prepared samples. The analysis results indicate that the porous carbon microspheres has a high specific surface area of 1163 m2 g−1 and a satisfactory small mesoporous texture (2∼5 nm), with the mean pore size of 3.24 nm and the pore volume ratio of 2∼5 nm pores up to 92%. The capacitive performances of the samples in 6 mol L−1 KOH aqueous electrolyte, have been tested by cyclic voltammetry, electrochemical impedance spectroscopy and charge-discharge techniques. A specific capacitance of 171.5 F/g is obtained for the porous carbon microspheres via charge-discharge at a current density of 1000 mA/g. It also displayed a very high cycle stability of 97.8%, compared with the initial capacitance, after 1000 cycles at the high current density of 1000 mA/g

  9. 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.

  10. Miniature electrometer preamplifier effectively compensates for input capacitance

    Science.gov (United States)

    Burrous, C. N.; Deboo, G. J.

    1966-01-01

    Negative capacitance preamplifier using a dual MOS /Metal Oxide Silicon/ transistor in conjunction with bipolar transistors is used with intracellular microelectrodes in recording bioelectric potentials. Applications would include use as a pickup plate video amplifier in storage tube tests and for pH and ionization chamber measurements.

  11. 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

  12. Stray capacitances in the watt balance operation: electrostatic forces

    DEFF Research Database (Denmark)

    Quagliotti, Danilo; Mana, G.

    2014-01-01

    In a watt balance, stray capacitances exist between the coil and the magnet. Since the electric current flowing in the coil creates a difference in electric potentials between the coil and magnet, their electrostatic interactions must be taken into account. This paper reports the results of a...

  13. Capacitive deionization on-chip; desalination of small volume samples

    NARCIS (Netherlands)

    Roelofs, S.H.; Rooijen, van M.; Kim, B.; Han, J.; Berg, van den A.; Odijk, M.

    2014-01-01

    This abstract demonstrates, for the first time, capacitive deionization (CDI) inside a chip measured using impedance spectroscopy [1]. CDI is a promising technique for the pre-treatment of extremely small volume protein samples (nL range) before analysis by mass spectroscopy [2]. The results include

  14. Probing 2D black phosphorus by quantum capacitance measurements.

    Science.gov (United States)

    Kuiri, Manabendra; Kumar, Chandan; Chakraborty, Biswanath; Gupta, Satyendra N; Naik, Mit H; Jain, Manish; Sood, A K; Das, Anindya

    2015-12-01

    Two-dimensional materials and their heterostructures have emerged as a new class of materials, not only for fundamental physics but also for electronic and optoelectronic applications. Black phosphorus (BP) is a relatively new addition to this class of materials. Its strong in-plane anisotropy makes BP a unique material for making conceptually new types of electronic devices. However, the global density of states (DOS) of BP in device geometry has not been measured experimentally. Here, we report the quantum capacitance measurements together with the conductance measurements on an hBN-protected few-layer BP (∼six layers) in a dual-gated field effect transistor (FET) geometry. The measured DOS from our quantum capacitance is compared with density functional theory (DFT). Our results reveal that the transport gap for quantum capacitance is smaller than that in conductance measurements due to the presence of localized states near the band edge. The presence of localized states is confirmed by the variable range hopping seen in our temperature dependence conductivity. A large asymmetry is observed between the electron and hole side. This asymmetric nature is attributed to the anisotropic band dispersion of BP. Our measurements establish the uniqueness of quantum capacitance in probing the localized states near the band edge, hitherto not seen in conductance measurements. PMID:26559656

  15. 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

  16. Quantum superposition of charge states on capacitively coupled superconducting islands

    NARCIS (Netherlands)

    Heij, C.P.; Dixon, D.C.; Wal, C.H. van der; Hadley, P.; Mooij, J.E.

    2003-01-01

    We investigate the ground state properties of a system containing two superconducting islands coupled capacitively by a wire. The ground state is a macroscopic superposition of charge states, even though the islands cannot exchange charge carriers. The ground state of the system is probed by measuri

  17. Deep-Hole Inner Diameter Measuring System Based on Non-contact Capacitance Sensor

    Institute of Scientific and Technical Information of China (English)

    于永新; 张恒; 王宗超; 常以哲

    2010-01-01

    A precise aperture measuring system of small deep holes with capacitance sensors is presented. Based on the working principle of non-contact capacitance sensors, influence of the edge effect of gauge head is studied, and one capacitance sensor for measuring the aperture of the small blind holes or through holes is introduced. The system is composed of one positioning device, one aperture measuring capacitance sensor, one measuring circuit, and software. This system employs visual CCD and two-dimensional mic...

  18. Characterization and Modeling of Subfemtofarad Nanowire Capacitance Using the CBCM Technique

    OpenAIRE

    Zhao, Hui; Kim, Raseong; Paul, Abhijeet; Luisier, Mathieu; Klimeck, Gerhard; Ma, Fa-Jun; Rustagi, Subhash; Ganesh S. Samudra; Singh, Navab; Lo, Guo-Qiang; Kwong, Dim-Lee

    2009-01-01

    The experimental characterization of gate capacitance in nanoscale devices is challenging. We report an application of the charge-based capacitance measurement (CBCM) technique to measure the gate capacitance of a single-channel nanowire transistor. The measurement results are validated by 3-D electrostatic computations for parasitic estimation and 2-D self-consistent sp(3)s*d5 tight-binding computations for intrinsic gate capacitance calculations. The device simulation domains were construct...

  19. Characterization and Modeling of Subfemotofarad Nanowire Capacitance Using the CBCM Technique

    OpenAIRE

    Zhao, Hui; Kim, Raseong; Paul, Abhijeet; Luisier, Mathieu; Klimeck, Gerhard; Ma, Fa-Jun; Rustagi, Subhash C.; Ganesh S. Samudra; Singh, Navab; Lo, Guo-Qiang; Kwong, Dim-Lee

    2009-01-01

    The experimental characterization of gate capacitance in nanoscale devices is challenging. We report an application of the charge-based capacitance measurement (CBCM) technique to measure the gate capacitance of a single-channel nanowire transistor. The measurement results are validated by 3-D electrostatic computations for parasitic estimation and 2-D self-consistent sp3s∗d5 tight-binding computations for intrinsic gate capacitance calculations. The device simulation domains were constructed...

  20. On the capacitance of crystalline silicon solar cells in steady state

    OpenAIRE

    BARRO, FABE IDRISSA; SANE, Moustapha; ZOUMA, BERNARD

    2015-01-01

    In this work, an analytical approach is presented for modeling the capacitance of crystalline silicon solar cells. Based on a one-dimensional modeling of the cell, the excess minority carrier density, the photovoltage, and the capacitance are calculated. The motivation of this work are two-fold: to show base doping density and illumination effects on the capacitance of silicon solar cells, and to propose a determination technique for both dark capacitance and base doping density f...

  1. Theory of volumetric capacitance of an electric double-layer supercapacitor

    OpenAIRE

    Skinner, Brian; Chen, Tianran; Loth, M. S.; Shklovskii, B. I.

    2011-01-01

    Electric double layer supercapacitors are a fast-rising class of high-power energy storage devices based on porous electrodes immersed in a concentrated electrolyte or ionic liquid. As of yet there is no microscopic theory to describe their surprisingly large capacitance per unit volume (volumetric capacitance) of ~ 100 F/cm^3, nor is there a good understanding of the fundamental limits on volumetric capacitance. In this paper we present a non-mean-field theory of the volumetric capacitance o...

  2. Electrode Polarization in Glassy Electrolytes: Large Interfacial Capacitance Values and Indication for Pseudocapacitive Charge Storage

    OpenAIRE

    Mariappan, C. R.; Heins, T. P.; Roling, B.

    2009-01-01

    We study the electrode polarization behaviour of different Na-Ca-phosphosilicate glasses by measuring the differential capacitance between blocking Pt electrodes. At low applied dc bias voltages, we detect a linear capacitance regime with interfacial capacitance values considerably larger than expected from double layer theories and also considerably larger than found for ionic liquids with similar ion concentrations. With increasing bias voltages, the differential capacitance of interfacial ...

  3. Corrections to the Capacitance between Two Electrodes Due to the Presence of Quantum Confined System

    OpenAIRE

    Macucci, M.; K. Hess

    1998-01-01

    We have studied the capacitance between two parallel plates enclosing a quantum confined system and its dependence on the applied voltage. The concepts of capacitance and differential capacitance are discussed together with their applicability to systems characterized by single.electron tunneling. We determine the tunneling thresholds by means of a formalism based on the minimization of the system free energy and we retrieve, as a special case, Luryi's quantum capacitance formula. We apply ou...

  4. An Annular Mechanical Temperature Compensation Structure for Gas-Sealed Capacitive Pressure Sensor

    OpenAIRE

    Kohei Higuchi; Yonggang Jiang; Kazusuke Maenaka; Hidekuni Takao; Xiuchun Hao

    2012-01-01

    A novel gas-sealed capacitive pressure sensor with a temperature compensation structure is reported. The pressure sensor is sealed by Au-Au diffusion bonding under a nitrogen ambient with a pressure of 100 kPa and integrated with a platinum resistor-based temperature sensor for human activity monitoring applications. The capacitance-pressure and capacitance-temperature characteristics of the gas-sealed capacitive pressure sensor without temperature compensation structure are calculated. It is...

  5. Numerical investigations on electric field characteristics with respect to capacitive detection of free-flying droplets.

    Science.gov (United States)

    Ernst, Andreas; Mutschler, Klaus; Tanguy, Laurent; Paust, Nils; Zengerle, Roland; Koltay, Peter

    2012-01-01

    In this paper a multi-disciplinary simulation of a capacitive droplet sensor based on an open plate capacitor as transducing element is presented. The numerical simulations are based on the finite volume method (FVM), including calculations of an electric field which changes according to the presence of a liquid droplet. The volume of fluid (VOF) method is applied for the simulation of the ejection process of a liquid droplet out of a dispenser nozzle. The simulations were realised using the computational fluid dynamic (CFD) software CFD ACE+. The investigated capacitive sensing principle enables to determine the volume of a micro droplet passing the sensor capacitor due to the induced change in capacity. It could be found that single droplets in the considered volume range of 5 nL < V(drop) < 100 nL lead to a linear change of the capacity up to ΔQ < 30 fC. The sensitivity of the focused capacitor geometry was evaluated to be S(i) = 0.3 fC/nL. The simulation results are validated by experiments which exhibit good agreement. PMID:23112615

  6. Experimental observation of multi-layer excitation structure in capacitively coupled SF6 plasmas

    Science.gov (United States)

    Liu, Yong-Xin; Gao, Fei; Song, Yuan-Hong; Li, Xue-Chun; Wang, You-Nian

    2015-09-01

    Electron excitation dynamics in capacitively coupled SF6 plasmas driven at 9 MHz ~ 16 MHz are studied by using phase resolved optical emission spectroscopy (PROES) of trace rare gas. Multi-layer excitation structure inside the bulk plasma of capacitive discharges operating in SF6 is experimentally observed for the first time. Experimental results show that with the decrease of the rf power and/or the increase of the pressure, the multi-layer excitation structure becomes noticeable while the gap between two adjacent layers is almost kept constant. By increasing the driving frequency with a constant electrode gap, however, the number of layers increases while the layer gap decreases. The layer structure disappears at the driving frequency larger than 16 MHz. The electrode gap is found to have a negligible effect on the gap between two adjacent excitation layers, nevertheless only the number of excitation layers is increased when enlarging the electrode gap. The multi-layer formation may be due to a large modulation of the F- negative-ion density throughout the bulk plasma, and is more pronounced at intermediate and low frequencies, since F- negative ions do not respond to the time-varying electric field at high frequencies (>16 MHz). This work was supported by the National Natural Science Foundation of China (NSFC) (Grant No. 11335004) and (Grant No.11405018), and the International Science & Technology Cooperation Program of China (Grant No. 2012DFG02150).

  7. Numerical Investigations on Electric Field Characteristics with Respect to Capacitive Detection of Free-Flying Droplets

    Directory of Open Access Journals (Sweden)

    Peter Koltay

    2012-08-01

    Full Text Available In this paper a multi-disciplinary simulation of a capacitive droplet sensor based on an open plate capacitor as transducing element is presented. The numerical simulations are based on the finite volume method (FVM, including calculations of an electric field which changes according to the presence of a liquid droplet. The volume of fluid (VOF method is applied for the simulation of the ejection process of a liquid droplet out of a dispenser nozzle. The simulations were realised using the computational fluid dynamic (CFD software CFD ACE+. The investigated capacitive sensing principle enables to determine the volume of a micro droplet passing the sensor capacitor due to the induced change in capacity. It could be found that single droplets in the considered volume range of 5 nL < Vdrop < 100 nL lead to a linear change of the capacity up to ΔQ < 30 fC. The sensitivity of the focused capacitor geometry was evaluated to be Si = 0.3 fC/nL. The simulation results are validated by experiments which exhibit good agreement.

  8. On the design of capacitive sensors using flexible electrodes for multipurpose measurements.

    Science.gov (United States)

    Thibault, Pierre; Diribarne, Pantxo; Fournier, Thierry; Perraud, Sylvain; Puech, Laurent; Wolf, P-Etienne; Rousset, Bernard; Vallcorba, Roser

    2007-04-01

    This article evaluates the potential of capacitive measurements using flexible electrodes to access various physical quantities. These electrodes are made of a thin metallic film, typical thickness 0.2 microm, evaporated on a plastic substrate. Their large flexibility enables them to be mounted in complex geometries such as curved surfaces. In the configuration of planar condensers, using a very sensitive commercial capacitive bridge and a three-terminal measurement method, several measurements are presented. A relative resolution of 10(-8) for the thermal expansion of samples is obtained at low temperature in a differential configuration. The same technique adopted for pressure gauge measurements at low temperature led to a typical 0.1 Pa resolution over a dynamic range of 10(4) Pa. In the configuration of interleaved electrodes, condensers have been used to measure wetting by either bulk liquid helium or by thin continuous helium films in a cylindrical pipe. Both experimental and numerical evidence is provided, showing that the close proximity of a reference ground potential significantly increases the relative sensitivity to fluid wetting. Further, interleaved electrodes can be used to access both the area that is covered by a liquid film but also to determine the thickness of this film, provided it is comparable to the periodicity of the electrode pattern. PMID:17477677

  9. Where is my car? Examining wayfinding behavior in a parking lot

    Directory of Open Access Journals (Sweden)

    Rodrigo Mora

    2014-08-01

    Full Text Available This article examines wayfinding behavior in an extended parking lot belonging to one of the largest shopping malls in Santiago, Chile. About 500 people were followed while going to the mall and returning from it, and their trajectories were mapped and analyzed. The results indicate that inbound paths were, in average, 10% shorter that outbound paths, and that people stopped three times more frequently when leaving the mall than when accessing it. It is argued that these results are in line with previous research on the subject, which stress the importance of environmental information in shaping people`s behavior.

  10. Stochastic Reorder Point-Lot Size (r,Q) Inventory Model under Maximum Entropy Principle

    OpenAIRE

    Davide Castellano

    2015-01-01

    This paper takes into account the continuous-review reorder point-lot size (r,Q) inventory model under stochastic demand, with the backorders-lost sales mixture. Moreover, to reflect the practical circumstance in which full information about the demand distribution lacks, we assume that only an estimate of the mean and of the variance is available. Contrarily to the typical approach in which the lead-time demand is supposed Gaussian or is obtained according to the so-called minimax procedure,...

  11. Simplified Capacitance Monitoring for the Determination of Campylobacter spp. Growth Rates

    Science.gov (United States)

    Capacitance monitoring is commonly used as an efficient means to measure growth curves of bacterial pathogens. However, the use of capacitance monitoring with Campylobacter spp. was previously determined difficult due to the complexity of the required media. We investigated capacitance monitoring ...

  12. Lot Sizing at the Operational Planning and Shop Floor Scheduling Levels of the Decision Hierarchy of Various Production Systems

    OpenAIRE

    Chen, Ming

    2007-01-01

    The research work presented in this dissertation relates to lot sizing and its applications in the areas of operational planning and shop floor scheduling and control. Lot sizing enables a proper loading of requisite number of jobs on the machines in order to optimize the performance of an underlying production system. We address lot sizing problems that are encountered at the order entry level as well as those that are faced at the time of distributing the jobs from one machine to another an...

  13. Comprehensive characterization of interface and oxide states in metal/oxide/semiconductor capacitors by pulsed mode capacitance and differential isothermal capacitance spectroscopy

    OpenAIRE

    Muret, Pierre

    2014-01-01

    In metal/insulator/semi-conductor structures, capacitance-voltage characteristics and capacitance or voltage transients can be measured in different conditions, which are described and implemented. Each method contains information about charges which are accommodated, captured or emitted by energy levels or bands at interface and inside the oxide. Pulsed capacitance measurements and differential isothermal procedures are analysed and performed. Calibration of the energy scale from the interfa...

  14. Consuming Web Services on Android Mobile Platform for Finding Parking Lots

    Directory of Open Access Journals (Sweden)

    Isak Shabani

    2015-02-01

    Full Text Available Many web applications over the last decade are built using Web services based on Simple Object Access Protocol (SOAP, because these Web services are the best choice for web applications and mobile applications in general. Researches and the results of them show how architectures and the systems primarily designed for use on desktop such as Web services calls with SOAP messaging, now are possible to be used on mobile platforms such as Android. The purpose of this paper is the study of Android mobile platform, more precisely the ability of this platform for consuming Web services and exploring existing alternatives for consuming Web services from this platform. People use their vehicles every day for transport and this of course leads to a constant demand for finding a parking lot. In this paper is proposed the system, named as MyParking through which it is aimed to facilitate users finding a parking lot for their vehicle depending on their current location. MyParking consists of three modules: Android client, administration and Web services.

  15. Demonstration Assessment of Light-Emitting Diode (LED) Parking Lot Lighting in Leavenworth, KS

    Energy Technology Data Exchange (ETDEWEB)

    Myer, Michael; Kinzey, Bruce R.; Curry, Ku' uipo

    2011-05-06

    This report describes the process and results of a demonstration of solid-state lighting (SSL) technology in a commercial parking lot lighting application, under the U.S. Department of Energy (DOE) Solid-State Lighting Technology GATEWAY Demonstration Program. The parking lot is for customers and employees of a Walmart Supercenter in Leavenworth, Kansas and this installation represents the first use of the LED Parking Lot Performance Specification developed by the DOE’s Commercial Building Energy Alliance. The application is a parking lot covering more than a half million square feet, lighted primarily by light-emitting diodes (LEDs). Metal halide wall packs were installed along the building facade. This site is new construction, so the installed baseline(s) were hypothetical designs. It was acknowledged early on that deviating from Walmart’s typical design would reduce the illuminance on the site. Walmart primarily uses 1000W pulse-start metal halide (PMH) lamps. In order to provide a comparison between both typical design and a design using conventional luminaires providing a lower illuminance, a 400W PMH design was also considered. As mentioned already, the illuminance would be reduced by shifting from the PMH system to the LED system. The Illuminating Engineering Society of North America (IES) provides recommended minimum illuminance values for parking lots. All designs exceeded the recommended illuminance values in IES RP-20, some by a wider margin than others. Energy savings from installing the LED system compared to the different PMH systems varied. Compared to the 1000W PMH system, the LED system would save 63 percent of the energy. However, this corresponds to a 68 percent reduction in illuminance as well. In comparison to the 400W PMH system, the LED system would save 44 percent of the energy and provide similar minimum illuminance values at the time of relamping. The LED system cost more than either of the PMH systems when comparing initial costs

  16. An Analytical Model for Fringing Capacitance in Double gate Hetero Tunnel FET and Analysis of effect of Traps and Oxide charges on Fringing Capacitance

    Directory of Open Access Journals (Sweden)

    Brinda Bhowmick

    2012-02-01

    Full Text Available In this paper fringe capacitance of double hetero gate Tunnel FET has been studied. The physical model for fringe capacitance is derived considering source gate overlap and gate drain non overlap. Inerface trap charge and oxide charges are also introduced under positive bias stress and hot carrier stress and their effect on fringe capacitance is also studied. The fringe capacitance is significant speed limiter in Double gate technology. The model is tested by comparing with simulation results obtained from Sentauras TCAD simulations.

  17. MEMS Capacitive Pressure Sensors: A Review on Recent Development and Prospective

    Directory of Open Access Journals (Sweden)

    Eswaran P

    2013-06-01

    Full Text Available Recently MEMS Capacitive Pressure Sensor gains more advantage over micromachined piezoresistive pressure sensor due to high sensitivity, low power consumption, free from temperature effects, IC compatibility, etc,. The spectrum of capacitive pressure sensor application is increasing, hence it is essential to review the path of technological development and further prospective of micromachinedcapacitive pressure sensor. This paper focuses on the review of various types of capacitive pressure sensor principle, MEMS materials used in fabrication, procedures adopted in microfabrication for silicon and polymer material diaphragm, bonding and packaging techniques used. Selected result on capacitive sensitivity, effect of temperature on capacitive sensitivity was also presented. Finally, the development of smart sensor was discussed.

  18. Study of materials for the design of MEMS capacitive pressure sensor

    Science.gov (United States)

    Jindal, Sumit Kumar; Raghuwanshi, Sanjeev Kumar

    2016-04-01

    Highly sensitive MEMS capacitive pressure sensor is nowadays used for many different applications such as aerospace, automobile, Bio-MEMS etc. This paper deals with study and comparison of different types of materials that can be used in design of MEMS capacitive pressure sensor. Initially principle and design of basic MEMS capacitive pressure sensor is explained. In the next section the properties of different materials is elaborated. The centre deflection of the diaphragm is calculated using COMSOL Multiphysics and Capacitance is calculated using MATLAB simulation. From the capacitance calculated sensitivity of the materials can be interpreted. The analysis is carried out for a pressure range of 0 to 0.1 MPa.

  19. Numerical Study of a System of Long Josephson Junctions with Inductive and Capacitive Couplings

    Science.gov (United States)

    Rahmonov, I. R.; Shukrinov, Yu. M.; Plecenik, A.; Zemlyanaya, E. V.; Bashashin, M. V.

    2016-02-01

    The phase dynamics of the stacked long Josephson junctions is investigated taking into account the inductive and capacitive couplings between junctions and the diffusion current. The simulation of the current-voltage characteristics is based on the numerical solution of a system of nonlinear partial differential equations by a fourth order Runge-Kutta method and finite-difference approximation. A parallel implementation is based on the MPI technique. The effectiveness of the MPI/C++ code is confirmed by calculations on the multi-processor cluster CICC (LIT JINR, Dubna). We demonstrate the appearance of the charge traveling wave (CTW) at the boundary of the zero field step. Based on this fact, we conclude that the CTW and the fluxons coexist.

  20. Quantum fluctuations of mesoscopic damped mutual capacitance coupled double resonance RLC circuit in thermal excitation state

    Institute of Scientific and Technical Information of China (English)

    XU Xing-Lei

    2007-01-01

    Mesoscopic damped mutual capacitance coupled double resonance circuit is quantized by the method of damped harmonic oscillator quantization. Hamiltonian is diagonalized by the method of unitary transformation. The energy spectra of this circuit are given. The quantum fluctuations of the charge and current of each loop are investigated by the method of thermofield dynamics (TFD) in thermal excitation state,thermal squeezed vacuum state,thermal vacuum state and vacuum state. It is shown that the quantum fluctuations of the charge and current are related to not only circuit inherent parameter and coupled magnitude,but also quantum number of excitation,squeezed coefficients,squeezed angle and environmental temperature. And the quantum fluctuations increase with the increase of temperature and decay with time.