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Scan Rate Dependent Morphology of Polyaniline Films Electrochemically Deposited on Nickel

Scan Rate Dependent Morphology of Polyaniline Films Electrochemically Deposited on Nickel

The effect of scan rate on the morphology and properties of polyaniline has been investigated for samples deposited electrochemically on nickel from sulfuric acid solution. A nanofibrilar network structure has been obtained for low scan rates (10, 25 and 50 mV s -1 ) whereas for the highest scan rate (100 mV s -1 ) the structure was more compact, the nanofibrils aggregated and their features were not very obvious. Both diameter and length of nanofibers are scan rate dependent, decreasing from 140 to 90 nm and from 1.35 to 0.72 μm when the scan rate is increased from 10 to 50 mV s -1 . The nanofiber network tends to be more compact and with less free-volume as the scan rate is increased. Generally, high specific capacitances and low charge transfer resistance values are obtained for all nanofibrilar polyaniline films as compared to the compact structure. The optimum scan rate for deposition was found to be 25 mV s -1 , leading to the highest specific capacitance and lowest charge transfer resistance.

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Concentration and scan rate dependent electrochemical measurements using a floating electrode

Concentration and scan rate dependent electrochemical measurements using a floating electrode

Figure 16b again shows the voltage as function of the time. This time the bulk is a 100 uM redox species solution. The potential over the bottom electrode is measured. The scan rate is 50 mV/s. The graph shows five measurements done on three different days. Between the three days, the device is stored in milli-Q water. Again the same measurement yields different results. The three measurements done on the same day differ a little bit. The solution between the first and second measurement is refreshed. This could explain the difference between the measurements on the same day. The peak-to-peak value is around 0.326 V. The peak-to-peak value for the first two days are 0.2841 V and 0.2735 V respectively. It is possible that the surface of the electrodes changes during storage. This is a problem when the device has to be used several days in a row.

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Rate Independent and Rate Dependent Structural Evolution during Severe Plastic Deformation

Rate Independent and Rate Dependent Structural Evolution during Severe Plastic Deformation

rence of the observed steady state at large strains. In general, boundaries are mobile and annihilate each other which finally lead to an equiaxed microstructure with mainly high-angle boundaries. Although the exact processes governing the movement of the boundaries are not clear in the case of HPT deformation, the driving force for the boundary migration seems be the reduction of the density of dislocations and the rate determining step the mobility of the boundaries. Because dynamic recrystallization is a diffusion-controlled process, it is enhanced by deformation at high homologous temperatures and influenced by the strain rate as well. The temperature dependence of the size of the structural elements in the saturation, the strain rate sensitivity and influence of the deformation temperature on the onset of the steady state during HPT deformation at high homologous temperatures would encourage this assumption. The morphology of the grains and the microtextural change in the saturation region at high deformation temperatures corroborates this further.

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Strain rate dependent mechanical properties of the equine hoof wall

Strain rate dependent mechanical properties of the equine hoof wall

Although equine hoof wall is loaded primarily in compression (Thomason et al. 1992), hoof tissue probably ultimately fails in tension. Tensile properties are therefore of primary interest when evaluating hoof performance. Fracture mechanics is important because, although the total energy input to a material may appear sufficient to characterise the toughness of a material, it provides no information about the behaviour of a material with a crack or a flaw. Linear elastic fracture mechanics (LEFM; see Broek, 1982) attempts to quantify the fracture toughness of a material given the knowledge of a few mechanical parameters generated from simple tests. One toughness parameter attainable from LEFM is the strain energy release rate G. This parameter represents the strain energy released per unit length of crack growth and was developed for linear elastic materials where all energy released during crack propagation equals the surface energy of the newly formed surface. In many materials, however, energy is absorbed by crack tip plasticity (permanent deformation of the material at the crack tip) as well as by the formation of new surfaces during crack propagation. For materials in which plasticity effects are significant, the J-integral technique provides a more accurate measure of toughness. J is a measure of the change in energy per unit change in crack length (Rice, 1968). In purely elastic materials, G and J are equal.

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Nonlinear and Rate Dependent Hysteretic Responses of Active Hybrid Composites

Nonlinear and Rate Dependent Hysteretic Responses of Active Hybrid Composites

PZT fillers and dominate the transverse response. The free strains, however, significantly decrease in both transverse and longitudinal fiber directions as the amount of PZT fillers increase. This is due to the fact that adding stiffer PZT particles in a softer epoxy matrix results in a stiffer overall matrix. Thus, adding PZT fillers is useful for improving the blocked stress for active composites with 3 - 1 operating mode. Responses of the hybrid piezocomposites under cyclic electric field, with amplitude higher than the coercive electric field limit of the materials, and compressive stress loadings have been studied. Adding PZT fillers slightly reduces the hysteretic polarization response, and significantly decreases the hysteretic strain response. As the matrix becomes stiffer, matrix would experience smaller deformations when an electric field input is applied, resulting in smaller resi- dual stresses 7 in both fibers and matrix. Although its effect is minimum, the residual stress would affect the overall hysteretic polarization in composites. As also expected compressive stresses applied along the direction of electric field reduce the polarization capability of the composites. We also investigate the effect of frequen- cies on the overall electro-mechanical responses of hybrid composites. A lower frequency input allows the hy- brid piezocomposites to undergo more pronounced time-dependent response, which in this case is shown by broader hysteretic responses. The hysteretic response indicates amount of energy being dissipated, which is converted into heat. It is noted that many applications of active materials would involve cyclic electro-mechan- ical loading, thus the hysteretic response can eventually lead to cyclic failures.

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Modelling rate dependent behaviour of orthotropic metals

Modelling rate dependent behaviour of orthotropic metals

The validation process is divided into two main parts. The first part, generally, is a preliminary validation process to systematically validate each part of the proposed formulations. This methodology facilitates the process to correct any error when it is found in any part of the formulations. For this purpose, three material models available in the LLNL-DYNA3D code are accordingly adopted; Material Types 10, 22 and 33. These material models are used to validate the elastic isotropy, the elastic orthotropy and the elastic-plastic formulations, respectively. This preliminary part of the validation process is finalised by examining the strain rate and temperature sensitivity of the proposed material model.

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Experimental characterisation of rate-dependent compression behaviour of fibre reinforced composites

Experimental characterisation of rate-dependent compression behaviour of fibre reinforced composites

There have been few studies dealing with experimen- tal characterisation of the strain rate dependent behaviour of uni-directional(UD) FRPs under multi-axial load states [1-4]. Koerber et al. [1] studied the in-plane compres- sive response of UD carbon fibre composites using off-axis coupons at quasi-static (QS) and high rate (HR). An aver- age increase of 12% and 45% was observed for the case of transverse compressive modulus and failure strength with strain rate, respectively. However, no significant change in the ultimate failure strain was found. Naresh et al. [2] studied the tensile response of GFRP, CFRP and hybrid composites at HR using a droptower setup. No signifi- cant strain rate dependency was observed for the case of tensile strength and modulus of CFRP material. More re- cently, Tao et al. [3] studied the QS and HR inter-fibre fail- ure behaviour of off-axis UD GFRP coupons under trans- verse tension and compression. Significant expansion of

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Procurement and Pricing Decision for Trapezoidal Demand Rate and Time Dependent Deterioration

Procurement and Pricing Decision for Trapezoidal Demand Rate and Time Dependent Deterioration

In recent years, inventory model for deteriorating items gets focus of many researchers. Deteriorating items having more importance due to high margin which also results high loss associated with them. In real life deterioration is a natural phenomenon which can be defined as a process of becoming impaired or inferior in quality from being used for its original purpose. It is quite essential for the consideration of deterioration rate in the analysis of items like fruits, vegetables, perfumes, pharmaceutical, radioactive substances etc.. With a view to address this research problem and provide pragmatic solution on offer several inventory models have been developed in the past. These models began with classical inventory model [24]-[25] these studies explicitly states that depletion of inventory model is primarily due to constant demand rate. Effects of deterioration on fashion products after their prescribed dates were studied by [26]-[27]. [1] established no shortage inventory model for deteriorating items with constant demand rate and constant deterioration rate. Similarly [2] considered classical Economic Order Quantity (EOQ) model with linearly deterministic demand rate. Since then, many researchers have exploited deteriorating model with time varying demand, presuming various assumptions for example[3]-[6] and [3] examined the non-shortage inventory model with a linear dependent on time trend in demand whereas [4]

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Convergence rate for the moving least squares learning with dependent sampling

Convergence rate for the moving least squares learning with dependent sampling

We consider the moving least-squares (MLS) method by the regression learning framework under the assumption that the sampling process satisfies the α -mixing condition. We conduct the rigorous error analysis by using the probability inequalities for the dependent samples in the error estimates. When the dependent samples satisfy an exponential α -mixing, we derive the satisfactory learning rate and error bound of the algorithm.

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Benefits of Using Lode Angle Dependent Fracture Models to Predict Ballistic Limits of Armor Steel

Benefits of Using Lode Angle Dependent Fracture Models to Predict Ballistic Limits of Armor Steel

Abstract. Ductile fracture experiments are carried out at different stress states, strain rates and temperatures on a range of flat Mars 300 steel specimens to calibrate both a plasticity and a fracture model. To predict the onset of fracture a stress state and strain rate-dependent Hosford–Coulomb fracture initiation model is used. Single material impact experiments are performed on targets of homogenous and perforated Mars 300 plates by accelerating cylindrical Mars 300 impactors in a single-stage gas gun. It is shown that the chosen modeling approach allows accurate modeling of the plastic response as well as the fracture patterns.

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A stochastic SIR epidemic model with density dependent birth rate

A stochastic SIR epidemic model with density dependent birth rate

Here N(t) = S(t) + I(t) + R(t) and β >  is the transmission coefficient, δ = α + γ + μ, and α is a non-negative constant and represents the death rate due to disease. γ >  is the rate constant for recovery. They use N as a variable in place of S; then the SIR model is described by the following system of differential equations:

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On the Determinants of Unemployment Rate in Nigeria: Evidence from Fully Modified OLS and Error Correction Model

On the Determinants of Unemployment Rate in Nigeria: Evidence from Fully Modified OLS and Error Correction Model

The FMOLS model also revealed that Interest Rate and Inflation Rate are negatively related to Unemployment but only Interest Rate is Significant (P-value = 0.0124 ˂ 0.05). This means that if there is unit increase in Inflation Rate, Unemployment Rate will decrease by 0.16 per unit increase in Inflation Rate. Also, if there is unit increase in Interest Rate, Unemployment Rate will decrease by 1.28 per unit increase in Interest Rate. This agrees with (Alisa 2015)., The Coefficient of determination (R-squared) shows that 74 % variation in unemployment rate can be explained jointly by four independent variables such as log of Interest Rate, log of Exchange Rate, log of inflation rate and log of Population growth. The rest 26% variation in Unemployment Rate can be explained by residuals or other variables other than the four independent variables. The FMOLS model also revealed that the variables are cointegrated, no presence of Multicollinearity, the expected fitted values of the model are close to the actual while the Error from the model are normally distributed which fulfil the assumption of the OLS . To understand the Short run Dynamics among these macro variables, the ECM model was adopted. The VAR selection criteria revealed that an optimum Lag of 2 was selected. The fitted ECM model revealed a Short Run impact from Exchange Rate to Unemployment Rate in Nigeria. This also implies that Nigerian economy depend on Importation. This agrees with the work of Nyahokwe & Ncwadi (2013). While the ECM coefficient is –0.489 which has the expected sign and it is also significant, this means that for the system to come to equilibrium, it takes a speed up of 48.9% annually. This agrees with the work of Alisa (2015).

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Inventory model with inventory-level-dependent demand rate without shortages

Inventory model with inventory-level-dependent demand rate without shortages

It is common belief that the presence of inventory has a motivational effect on the people around it. Attempts have been made to consider inventory level dependent demand rate by researchers like Baker and Urban (1988), Mandal and Phaujdar (1989), who studied a situation of this type. One more paper by Mandal and Phaujdar (1989) included deterioration alongwith stock dependent demand rate. Dutta and Pal (1990) developed a model with same concept. In the same year Dutta and Pal (1990) extended their own model by providing shortages. Similarly Gupta and Vrat (1986) studied model with stock dependent demand rate, in another paper Gupta and Vrat (1986) covered the possibility of multi items. Recently Chao-Ton Su, Lee-Ing Ton and Hung-Chang Liao (1996) studied a deteriorating inventory model with inflation and stock dependent demand rate.

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EOQ model with shortages for products with controllable deterioration rate and time dependent demand and inventory holding cost

EOQ model with shortages for products with controllable deterioration rate and time dependent demand and inventory holding cost

deteriorating items where time to deterioration has Exponential distribution and with time-dependent quadratic demand. In this model, shortages are not allowed and holding cost is time-dependent. Also, Gothi and Kirtan Parmar (2015) have extended above deterministic inventory model by taking two parameter Weibull distributions to represent the distribution of time to deterioration and shortages are allowed and partially backlogged. Kirtan Parmar and Gothi (2015) developed an economic production model for deteriorating items using three parameter Weibull distributions with constant production rate and time varying holding cost. The consideration of PT is important due to rapid social changes, and the fact that PT can reduce the deterioration rate significantly. By the efforts of investing in preservation technology, we can reduce the deterioration rate. So in this paper, we made the model of Mishra and Singh (2011) more realistic by considering the fact that use of preservation technology can reduce the deterioration rate significantly, which help the retailers to reduce their economic losses. We have analyzed an inventory system for deteriorating items under quadratic demand using preservation technology and time dependent IHC. The assumptions and notations of the model are introduced in the next section. The mathematical model and Analysis is derived and numerical illustration is presented. The article ends with some concluding remarks and scope of a future research.

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Fuzzy EOQ model for controllable deterioration rate and time dependent demand and Inventory holding cost

Fuzzy EOQ model for controllable deterioration rate and time dependent demand and Inventory holding cost

Inventory may be considered as an accumulation of a product that would be used to satisfy future demands for that product. An carrying cost and shortage cost. An important problem confronting a supply manager in any modern organization is the control and maintenance of inventories of deteriorating items. ys, glassware, hardware, etc. There is little requirement for considering deterioration in the determination of economic lot size. So in this paper, an inventory model is developed for technology the retailer can reduce the deterioration rate by which he can reduce the economic losses, improve the customer service level and increase business competitiveness. In reality, the t. Time also plays and important role in the inventory system. Recently, Mishra and Singh (2016) developed a deteriorating inventory model with partial backlogging when demand and deterioration rate is constant. Vinod kumar Mishra developed an inventory model of instantaneous deteriorating items with controllable deterioration rate for time dependent developed deteriorating inventory model with controllable deterioration 2015) developed EOQ model with formulated a deteriorating inventory model dependent demand by allowing preservation technology cost as a decision variable in conjunction with replacement by assuming that the preservation technology cost developed an order level inventory quadratic demand and partial backlogging. Sarala Pareek and Garima Sharma (2014) developed an inventory model with Weibull distribution deteriorating item with exponential declining demand and partial

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Gholami, Azam
  

(2007):


	Actin-based motility.


Dissertation, LMU München: Fakultät für Physik

Gholami, Azam (2007): Actin-based motility. Dissertation, LMU München: Fakultät für Physik

Listeria monocytogenes is a Gram-positive bacterium, named for Joseph Lister. It is a cylinder-like object with radius of around 0.5 µm and length of 1.5 µm. Listeria hijacks actin monomers from the host cell and assem- ble them into a comet-like tail which is made up of oriented, cross-linked networks of actin filaments. Barbed (growing) ends of actin filaments are oriented toward the bacterial surface on which actin filaments polymerize with the same rate as that of the bacterial cell propulsion. This suggests that the actin polymerization drives the bacterium forward (Theriot et al., 1992). The actin comet is used as an anchor in the cytoplasm, so that as new polymerized actin is added between the bacterium surface and the older polymerized gel, the organism is propelled forward (Fig. 1.2b). Liste- ria moves through the host cytoplasm rapidly, with velocities of the order of tenth of a micron per second (Cameron et al., 2001). The wild-type of Listeria is observed to move with a constant velocity but Listeria mutant ActA ∆21−97 shows oscillatory motion with a period around 100 sec. This

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Large zero tension plate lysimeters for soil water and solute collection in undisturbed soils

Large zero tension plate lysimeters for soil water and solute collection in undisturbed soils

Large zero-tension plate lysimeters can be useful devices to collect water from preferential flow paths, as shown by sim- ulation studies and a tracer experiment. With the new mod- ular plate system, large water collection surfaces can be re- alized, while leaving the soil above the lysimeter completely undisturbed. This study shows that the collection efficiency of zero-tension plate lysimeters is highly dependent on the hydraulic properties. Especially the shape of the hydraulic functions close to saturation influences the collection effi- ciency. In soils with high conductivities near saturation, such as coarse soils or soils with a well-developed structural pore system, even large zero-tension plate lysimeters may be largely circumvented. In order to collect water from such soils, lysimeters with suction devices have to be used.

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Fuzzy inventory model for time dependent deteriorating items with lead time  stock dependent demand rate  and shortages

Fuzzy inventory model for time dependent deteriorating items with lead time stock dependent demand rate and shortages

In this paper a deterministic fuzzy inventory model for time dependent deteriorating items with lead time and stock dependent demand rate has been developed. The ordering cost, deterioration cost, holding cost and shortage cost are assumed as triangular fuzzy number. In this model shortages are allowed during the lead time and completely backlogged. An economic order quantity (EOQ) has been obtained. The derived model is illustrated by a numerical example.

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Existence-uniqueness and Monotone approximation for an erythropoiesis age-structured model

Existence-uniqueness and Monotone approximation for an erythropoiesis age-structured model

Benzene is a chemical found in both cigarette smoke and gasoline emissions [15, 17]; exposure to benzene results in a variety of blood and bone marrow disorders in both humans and laboratory animals [8, 10]. Modeling erythropoiesis was originally of interest because the toxicity of benzene in the bone marrow is of most importance. As was previously noted, the bone marrow is one of the primary sites where stem cells begin to proliferate and differentiate into red blood cells. Thus, exposure to benzene would contribute to the precursor cell death rate term, which is incorporated into the term σ(t, µ). This idea could certainly be used to investigate other chemicals or toxic agents that affect red blood cell production.

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Wind Energy Dependent Rate Adaptation for Roadside Units

Wind Energy Dependent Rate Adaptation for Roadside Units

Deployment of renewable energy sources for vehicular networks has recently become an area of research interest since the use of environmentally sound communications as well as power aware network architecture and protocols design are imperative [1-3]. In [4, 5] MAC protocols which are based mainly on communication channel quality have been proposed for vehicular networks. In a traditional non-adaptive RSU deployment, the RSU operates at a fixed data rate only when it has sufficient power and ceases to function otherwise. Our wind energy based rate adaptive technique allows the RSU to transmit at various data rates based on the available wind energy while maintaining an acceptable level of QoS. Such RSUs not only reduce the carbon footprint of vehicular networks but also are easily deployable.

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