Dependent Production Rate Research Articles

A pollution sensitive dense fuzzy economic production quantity model with cycle time dependent production rate

In recent times, environmental pollution is one of the most critical issues of any industrial set up throughout the globe. The excess of marginal pollution and risk for unsold goods (like chemical and plastic items etc.) and their decomposition play a vital role in any decision-making process. Also the uses of automation/technology in pollution control measures contributes to another kind of pollution drastically. Moreover, the waste products as well as factory outlet sewage water itself have some negative externalities on the environment. Keeping this fact in mind, we first define a new functional relation between environmental pollution rate and production rate. Then we describe an economic production quantity model with deterioration for cycle time dependent production rate. We include preservation technology cost to restrict the normal deterioration. Considering a real data set obtained from the case study of a sponge iron industry, we analyze the crisp model first, then we go for its fuzzification. Inspiring from the learning effects we have utilized a new fuzzy inference scheme based on the dense fuzzy rule. However, our findings suggest that to restrict pollution and financial loss, the decision-maker might have to control the gross production of the industry. Finally, sensitivity analysis and graphical illustrations are also provided to justify the model.

A partially backlogged EPQ model with demand dependent production and non-instantaneous deterioration

The present paper deals with a production inventory system for non-instantaneous deteriorating items with demand dependent production rate. It is assumed that demand rate is exponentially increasing function of time. Shortages are considered and partially backordered at a rate of decreasing function of waiting time for next replenishment. Herein, two cases for life time approach regarding the production stopping time point have been studied separately. The numerical examples have been provided separately to illustrate each case. Finally, sensitivity analysis has also been made to show the behaviour of presented model in each case.

Analysis of the radial potential structure and neutron production rate in the spherical inertial electrostatic confinement fusion devices

The radial dependent potential and neutron production rate in spherical inertial electrostatic confinement fusion (IECF) devices is investigated. The electrostatic potential is determined by solving the Poisson equation for various deuteron and electron distribution functions. The fusion reaction rates are determined using energy distribution function. Also, dependence of potential structure and neutron production rate on some important parameters as the ion and electron convergence, working pressure, kinetic energy of the secondary electrons emitted from the cathode and the fraction of secondary electrons drawn inside the cathode are studied. Total produced neutrons as a function of input power at different working conditions are also obtained.

Integrated production inventory model: multi-item, multiple suppliers and retailers, exponential demand rate

In this paper, an integrated production-inventory model with multi-item is developed from the perspectives of single producer, multiple suppliers and retailers. In this three-layer supply chain, the retailers are non-competing. Every supplier delivers only single type of raw material to the producer. The producer manufactures finished goods from the combination of fixed percentage of different types of raw materials. The producer manufactures various types of objects and supplies them to retailers according to the demand of multiple retailers. This paper studies the impact of different types of business policies such as exponential demand rate, demand dependent production rate, optimum order size of raw materials, and unit production cost at each stage of integrated marketing system. Mathematica is used to develop the model and to optimize the integrated profit function. A numerical example and sensitivity analysis is illustrated to justify the feasibility of the proposed model.

Nitric Oxide Transport in Normal Human Thoracic Aorta: Effects of Hemodynamics and Nitric Oxide Scavengers

Despite the crucial role of nitric oxide (NO) in the homeostasis of the vasculature, little quantitative information exists concerning NO transport and distribution in medium and large-sized arteries where atherosclerosis and aneurysm occur and hemodynamics is complex. We hypothesized that local hemodynamics in arteries may govern NO transport and affect the distribution of NO in the arteries, hence playing an important role in the localization of vascular diseases. To substantiate this hypothesis, we presented a lumen/wall model of the human aorta based on its MRI images to simulate the production, transport and consumption of NO in the arterial lumen and within the aortic wall. The results demonstrated that the distribution of NO in the aorta was quite uneven with remarkably reduced NO bioavailability in regions of disturbed flow, and local hemodynamics could affect NO distribution mainly via flow dependent NO production rate of endothelium. In addition, erythrocytes in the blood could moderately modulate NO concentration in the aorta, especially at the endothelial surface. However, the reaction of NO within the wall could only slightly affect NO concentration on the luminal surface, but strongly reduce NO concentration within the aortic wall. A strong positive correlation was revealed between wall shear stress and NO concentration, which was affected by local hemodynamics and NO reaction rate. In conclusion, the distribution of NO in the aorta may be determined by local hemodynamics and modulated differently by NO scavengers in the lumen and within the wall.

Order Size Dependent Trade Credit Study in a Three Echelon Supply Chain Model

In present study, we generalize order linked trade credit policy in three echelon supply chain system where manufacturer, distributor and retailer are involved and manufacturer provide a delay period to distributor and distributor also provide a order linked trade credit policy to his retailers. Whole study is discussed in time dependent production and demand rate. We model a three echelon supply chain system as cost minimization to determine the system’s optimal cycle time. In this paper, we determine the optimal cycle time, optimal order quantity and optimal payment time. Finally numerical examples are given to illustrate the result and the managerial insights are also obtained.

The Optimal Replenishment Policy under Trade Credit Financing with Ramp Type Demand and Demand Dependent Production Rate

This paper investigates the optimal replenishment policy for the retailer with the ramp type demand and demand dependent production rate involving the trade credit financing, which is not reported in the literatures. First, the two inventory models are developed under the above situation. Second, the algorithms are given to optimize the replenishment cycle time and the order quantity for the retailer. Finally, the numerical examples are carried out to illustrate the optimal solutions and the sensitivity analysis is performed. The results show that if the value of production rate is small, the retailer will lower the frequency of putting the orders to cut down the order cost; if the production rate is high, the demand dependent production rate has no effect on the optimal decisions. When the trade credit is less than the growth stage time, the retailer will shorten the replenishment cycle; when it is larger than the breakpoint of the demand, within the maturity stage of the products, the trade credit has no effect on the optimal order cycle and the optimal order quantity.

Cosmogenic nuclides in stony meteorites revisited

Abstract— We present new model calculations for depth and size dependent cosmogenic production rates in ordinary and carbonaceous chondrites by galactic cosmic rays. This model, essentially that of Leya et al. (2000a), folds together particle spectra and cross sections for the relevant nuclear reactions, but has been significantly improved due to major improvements in the neutron cross section database and better Monte Carlo modeling of the primary and the secondary particle spectra. The data presented here replace (and extend) the results of our earlier model predictions. Here we give for ordinary and carbonaceous chondrites elemental production rates for the cosmogenic radionuclides 10Be, 14C, 26Al, 36Cl, 41Ca, 53Mn, 60Fe, and 129I as well as for the noble gas isotopes 3He, 4He, 20Ne, 21Ne, 22Ne, 36Ar, and 38Ar. Using the new data and expressing size and depth scales to the unit [g/cm2], we are able to demonstrate that the matrix effect for both chondrite types is negligible for all target product combinations, except for those which are dominated by thermal or very low energy neutron reactions. Based on the new model predictions, we present a variety of elemental and isotopic production rate ratios allowing for a reliable determination of preatmospheric sizes, shielding depths, cosmic‐ray exposure ages, and diffusive losses.

Sediment burial dating using terrestrial cosmogenic nuclides

Abstract. Burial dating using in situ produced terrestrial cosmogenic nuclides is a relatively new method to date sediments and quantify geomorphological processes such as erosion, accumulation and river incision. Burial dating utilises the decay of previously in situ produced cosmogenic nuclides and can be applied to sedimentary deposits such as cave fillings, alluvial fans, river terraces, delta deposits, and dunes. Using the established 10Be/26Al nuclide pair allows numerical dating of quartz bearing material from ~100 ka to 5 Ma, where other dateable material is often unavailable. To date, a number of studies have demonstrated the successful application of in situ produced cosmogenic nuclides in various scientific disciplines, such as Quaternary geology, geomorphology and palaeoanthropology. However, insufficiently defined physical properties such as nuclide half lives and complex depth dependent nuclide production rates result in relatively large uncertainties. Nevertheless, burial dating represents a promising method for determining numerical ages.

Cooperative flow dynamics in production lines with buffer level dependent production rates

We study, in the fluid flow framework, the cooperative dynamics of a buffered production line in which the production rate of each work-cell does depend on the content of its adjacent buffers. Such state dependent fluid queueing networks are typical for people based manufacturing systems where human operators adapt their working rates to the observed environment. We unveil a close analogy between the flows delivered by such manufacturing lines and cars in highway traffic where the driving speed is naturally adapted to the actual headway. This close analogy is thoroughly explored. In particular, by investigating the dynamic response of small perturbations around free flow stationary regimes, we can draw a “phase diagram”. This diagram exhibits two different flow patterns, namely the free and jamming production regimes. The transitions between these regimes are tuned by the production control parameters (i.e. the buffer capacities, the reaction sensitivity, the control sampling time, etc.). We finally extract a dimensionless dynamic parameter directly relevant for design purposes.

On the optimality of inventory models with deteriorating items for demand and on-hand inventory dependent production rate

On the optimality of inventory models with deteriorating items for demand and on-hand inventory dependent production rate

Ion scattering on crystalline surfaces: Effects of surface track potential on secondary electron emission

Secondary electron (SE) yields induced by 0.5 MeV/u H +, He 2+ and Li 2+ ions reflected from semiconductor [SnTe(0 0 1)] and insulator [KCl(0 0 1)] surfaces are measured in coincidence with the reflected ions. The observed SE yield emitted by the Li ion is as large as 300–400 for SnTe(0 0 1) and 400–550 for KCl(0 0 1). These large SE yields suggest that a strong surface track potential is induced behind the Li ion at the surface, which might recapture the ejected SEs. To see the effect of the surface track potential, the position dependent SE production rate is derived from the observed SE yields. The obtained SE production rates for H, He and Li ions on the SnTe(0 0 1), however, agree with each other if the production rate is normalized by the observed mean square charge of the reflected ions. In the measurement with KCl(0 0 1), the crystal was heated at 180 °C to avoid the macroscopic charging. Nevertheless, the normalized SE production rate decreases with the atomic number of the projectile ion, suggesting that a part of the ejected SEs are recaptured by the induced surface track potential. The surface-track potential for SnTe might be as high as for KCl, but neutralization could be significantly faster. The surface-track potential, if it exists, may accelerate the projectile, and results in reduction of the surface stopping power. The observed surface stopping power of KCl(0 0 1) supports this scenario.

A production lot size model for deteriorating items with inventory level dependent production and demand rate

In this paper, a production lot size inventory model for deteriorating items with inventory-level dependent production and demand rate is developed. The production rate and demand both are dependent on the instantaneously level, and an alternative optimization technique is presented to derive an optimal production policy. The method is illustrated by a numerical example and a sensitivity analysis of the optimal solution with respect to parameters of the system is also carried out.

Analysis of a two-sided production policy with inventory-level-dependent production rates

In this paper we analyse a stochastic production/inventory problem with compound Poisson demand and state (i.e. inventory level) dependent production rates. Customers arrive according to a Poisson process where the amount demanded by each customer is assumed to have a general distribution. When the inventory W(t) falls below a critical level m, production is started at a rate of r[W(t)], i.e. production rate dynamically changes as a function of the inventory level. Production continues until a level M (œ w m) is reached. Excess demand is assumed to be lost. We identify a dam content process X that is a dual for the inventory level W and develop the stationary distribution for the X process. To achieve this we use tools from renewal and level crossing theories. The two-sided (m, M) policy is optimized using the expected cost obtained from the stationary density of W and a conditional (on w) expected cost function for this process. For a special case, we obtain explicit results for all the relevant expressions. Numerical examples are provided for several test problems. © 1996 John Wiley & Sons, Ltd.

Atom Transport in Nickel by Displacement Cascades for Spatially Dependent Displacement Rate and Sink Strength

AbstractAtom transport under irradiation is determined by the concentration of freely migrating defects, which depends on the dynamical equilibrium between production and annihilation rates. In order to determine effective values of both of these quantities for the case of ion irradiation, spatially resolved self-diffusion measurements were performed on single crystals of nickel which contained several thin tracer layers at different depths. By fitting the solution of a diffusion equation to the depth dependent measurements effective fractional production rates of freely migrating defects and effective sink strengths have been obtained.

On culturing Escherichia coli on a mineral salts medium during anaerobic conditions

The substrate and products of the hydrogenlyase complex, formic acid, carbon dioxide, and molecular hydrogen, are co-operatively implicated in maintaining growth of E. coli under anaerobic conditions. Growth is observed in the presence of a combination of carbon dioxide + molecular hydrogen, or carbon dioxide + formic acid in the medium. The study shows that it is possible to culture E. coli under anaerobic conditions while sparging with nitrogen, without supplementing exogenous carbon dioxide, formic acid or molecular hydrogen. This condition occurs when the strain is allowed an appropriate induction period and is present at a sufficiently high cell density, since the cell density affects the rate of e.g. CO2 production. In a system sparged with nitrogen gas, the removal of CO2 due to this sparging must be balanced with a cell density dependent production rate of CO2. It is concluded that the “formic hydrogenlyase complex” should be considered as an integral part of the general maintenance of the anabolism of E. coli during anaerobic conditions on a mineral salts medium, as well as being a net producer of end products in E. coli metabolism.

Common asteroid break-up events of eucrites, diogenites, and howardites and cosmic-ray production rates for noble gases in achondrites

We determined the cosmic-ray produced noble gas abundances in eight diogenites, four eucrites, and four howardites. Using these and additional noble gas and chemical data from the literature, composition and shielding dependent production rates of achondrites for 3He, 21Ne, 38Ar, 78Kr, 83Kr, and126Xe were derived based on 81KrKr exposure ages. The cosmogenic ratio 22Ne/21Ne is found to be a valid shielding indicator for all howardites, eucrites, and diogenites (HEDs). This ratio correlates with other shielding dependent ratios, such as 78Kr/83Kr, 80Kr/83Kr, 124Xe/131Xe, 126Xe/131Xe, and 128Xe/131Xe. We show that strong correlations for these ratios also exist for basaltic lunar rocks. The new production rates were used for the calculation of exposure ages for all HEDs with known noble gas abundances. Two major exposure age clusters at 21 Ma and 38 Ma are observed in all three classes. We find that five asteroid break-up events, characterized by exposure ages 6 ± 1 Ma, 12 ± 2 Ma, 21 ± 4 Ma, 38 ± 8 Ma, and 73 ± 3 Ma produced all diogenites, fifteen out of seventeen howardites, and twenty-eight out of thirty-nine eucrites. We conclude that asteroidal or cometary impact events at such times on one or several parent bodies are responsible for the ejection of eucrites, howardites, and diogenites. Probable parent bodies are multiple 4 Vesta-derived kilometer-sized objects of basaltic achondritic composition reaching the 3:1 resonance region, a proposed source area for meteorites. The direct ejection from Vesta and capture by Earth of basaltic meteorites has been shown to be dynamically difficult. In such a scenario large events 38 Ma and 21 Ma ago are required, liberating simultaneously material representing Vesta's surface (eucrites, howardites) and interior regions (diogenites).

Common asteroid break-up events of eucrites, diogenites, and howardites and cosmic-ray production rates for noble gases in achondrites

We determined the cosmic-ray produced noble gas abundances in eight diogenites, four eucrites, and four howardites. Using these and additional noble gas and chemical data from the literature, composition and shielding dependent production rates of achondrites for 3He, 21Ne, 38Ar, 78Kr, 83Kr, and126Xe were derived based on 81KrKr exposure ages. The cosmogenic ratio 22Ne/21Ne is found to be a valid shielding indicator for all howardites, eucrites, and diogenites (HEDs). This ratio correlates with other shielding dependent ratios, such as 78Kr/83Kr, 80Kr/83Kr, 124Xe/131Xe, 126Xe/131Xe, and 128Xe/131Xe. We show that strong correlations for these ratios also exist for basaltic lunar rocks. The new production rates were used for the calculation of exposure ages for all HEDs with known noble gas abundances. Two major exposure age clusters at 21 Ma and 38 Ma are observed in all three classes. We find that five asteroid break-up events, characterized by exposure ages 6 ± 1 Ma, 12 ± 2 Ma, 21 ± 4 Ma, 38 ± 8 Ma, and 73 ± 3 Ma produced all diogenites, fifteen out of seventeen howardites, and twenty-eight out of thirty-nine eucrites. We conclude that asteroidal or cometary impact events at such times on one or several parent bodies are responsible for the ejection of eucrites, howardites, and diogenites. Probable parent bodies are multiple 4 Vesta-derived kilometer-sized objects of basaltic achondritic composition reaching the 3:1 resonance region, a proposed source area for meteorites. The direct ejection from Vesta and capture by Earth of basaltic meteorites has been shown to be dynamically difficult. In such a scenario large events 38 Ma and 21 Ma ago are required, liberating simultaneously material representing Vesta's surface (eucrites, howardites) and interior regions (diogenites).

Analysis of production/inventory systems with several production rates

We consider four model classes with differing rules as to how to deal with the issue of backordering and shortages. For each model we assume N switchover levels and piecewise linear, state dependent and deterministic production rates between levels. We compute relevant functionals such as the stationary law of the inventory level, holding costs, switching and unsatisfied demand costs, and consider these with respect to two objective functions, namely, the long-run average cost, and the expected discounted cost.

Yield curves and beam current dependent production rates of Rb radioisotopes produced by protons on a krypton gas target

For the irradiation of krpton with protons in the energy interval 5–26 MeV the yield curves for the formation of 79Rb, 81 m Rb, 81Rb, 82 m Rb, 83Rb, 84 m Rb, 84Rb and 86Rb were measured. A comparison of four of these curves with those given by Lamb and Acerbi shows a good agreement. The measured yield curves show that in a 81Rb− 81 m Kr generator system 83Rb gives rise to small fractions (<10 −3) of 83 m Kr in the eluted 81 m Kr and that 83Rb is the main component of the waste activity of the generator system. Investigations on the beam current dependent production rate show, at a pressure of 400 kPa (4 bar), a decrease of about 15% of the initial gas density at the position of the proton beam of 16 μA, corresponding to a current density of 12 μA/cm 2.