Price determination in monopolistic markets with inventory adjustment

This paper presents a practical model for the analysis of the price determination mechanism in raw materials markets that are characterized by the dominance of a large firm. The model takes explicit note of the influence of inventory adjustments; it is postulated that the dominant firm?s decision on price and production levels is negatively related to the difference between actual and desired inventory levels. In a first empirical test, the model is applied to an analysis of the nickel industry. The empirical results support the hypothesized role of inventories and show the importance of inventory adjustments relative to the other factors determining price and production behavior.

Synthesis and Characterization of Co1-xSnx Magnetic Nanowires

High-density and uniform-sized Co1-xSnx alloy nanowires have been prepared electrochemically in anodic aluminum oxide (AAO) templates. This highly ordered arrays of nanowires have magnetic properties that affect by several agents including Sn concentration in structure of nanowires and annealing process. The morphologies of the nanowires were obtained by using the scanning electron microscope (SEM). The measurement of magnetic properties was made using the alternating gradient fors magnetometer (AGFM). The composition of the Co1-xSnx nanowires was analyzed by EDX. It has been observed that these properties were changed significantly with increasing of Sn content in nanowires. Also the affect of annealing temperature, up to 575˚C, on the magnetic properties and microstructure of as-prepared nanowires have been investigated. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3534

Effect of Electrodeposition Frequency on Magnetic Properties of (Co0.97Al0.03)0.7Fe0.3 Nanowires

The magnetic properties of (Co0.97Al0.03)0.7Fe0.3 nanowires electrodeposited at different frequency of 50- 1000 Hz were studied. This nanowires were prepared by alternative current electrodeposition using porous anodic aluminum oxide as template. The results show that coercivity of samples slightly increased with increasing the frequency. Comparing the M–H hysteresis loops in different frequency shows that saturation magnetization (Ms) per unit area decreases with increasing the frequency. Magnetic properties were also investigated after annealing at 575 C. After annealing, a clear increase in coercivity was observed. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3534

Effect of Current Frequency and Annealing on Magnetic Properties of [Co70Fe30]97Sn3 Nanowire Arrays

[Co70Fe30]97Sn3 alloy nanowire arrays have been fabricated by alternative current (ac) electrodeposition of Co2+, Fe2+ and Sn2+ into anodic aluminum oxide (AAO) templates. The samples were deposited at current frequency 50, 100, 200, 300, 400, 500, 800 and 1000 Hz, respectively. The structure and magnetic properties of [Co70Fe30]97Sn3 nanowire arrays dependence on different current frequency were analyzed by XRD and alternating gradient field magnetometer (AGFM). The X-ray diffraction patterns are shown an amorphous structure of the[Co70Fe30]97Sn3 nanowires. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3535

Appraisal of different ultrasonography indices in patients with carotid artery atherosclerosis

In this study a semi-automated image-processing based method was designed in which the parameters such as intima-media thickness (IMT), resistive index (RI), pulsatility index (PI), dicrotic notch index (DNI), and mean wavelet entropy (MWE) were evaluated in B-mode and Doppler ultrasound in patients presenting with carotid artery atherosclerosis. In a cross-sectional design, 144 men were divided into four groups of control, mild, moderate and severe stenosis subjects. In all individuals, far wall IMT, RI, PI, DNI, and MWE of the left common carotid artery (CCA) were extracted using the proposed method. Our findings showed that the maximum far wall IMT, RI, PI, DNI in the CCA were significantly different in the patients with mild, moderate, and severe stenosis compared to control group (p-value 0.05). The proposed method can help physicians to better identify patients at risk of cardiovascular diseases

Investigation on Phytoremediation Capability of Artiplex (Atriplex sp.) and Oleander (Nerium oleander) in Aradkooh Landfill for Cadmium and Lead

Intruduction Increasing industrial activities with the production of pollutants, including heavy metals, is one of the serious problems of modern communities, which has led to their accumulation in the environment. Heavy metals are also one of the important pollutants in landfill leachate. Plants and soil near the landfill may be contaminated by the leachate. Landfilling is the oldest method of solid waste disposal which can be a threat to the environment and health. Due to its easy operation and cost-effective, landfill is the most widely used method of municipal solid waste disposal in the world. Pollution cleaning technologies to reduce the harmful effects in the locations contaminated with heavy metals can be done by physical, chemical and biological methods. Phytoremediation, as a biological method, uses the green plants to extract, sequester, and detoxify pollutants. This method is a low-cost technique, environmentally friendly, and due to the non-production of by-products, is non-destructive for natural ecosystems. Considering the high moisture of wastes in Iran and their potential to produce leachate, as well as the possibility of contamination of water and soil in the landfill, especially with heavy metals, this study was conducted with the aim of evaluating the accumulation of lead (Pb) and cadmium (Cd) heavy metals in the soil, shoots and roots of artiplex (Atriplex sp.) and oleander (Nerium olander) plants in Aradkooh landfill of Tehran.   Materials and Methods This study was conducted in Aradkooh landfill which is located in the south of Tehran in the Kahrizak region. About 5200 tons of municipal solid waste were sent to this landfill every day. A part of the solid waste in Aradkoh was placed in various processes to energy and compost, and about 2500 tons of the solid waste was landfilled. According to previous reports, it is estimated that 250 cubic meters of leachate are produced daily in the Aradkoh landfill. In the studied landfill, there is an atriplex plant in four areas and a hand-planted oleander in one area. Ten samples of soil, root, and shoot, totaling 120 total were randomly selected from each growing area of the atriplex plant. Oleander shoots and soil were also tested from 10 different plants for a total of 40 samples. Then the levels of Cd and Pb in the soil, roots, and shoots were assessed. In this study, the outcomes were analyzed employing four key indices: the bioconcentration factor (BCF), the translocation factor (TF), the pollution index (PI), and PINemerow. The BCF and TF indices were employed to assess the phytoextraction and phytostabilization capabilities of plants, while the PI and PINemerow methods were used to pinpoint the most environmentally hazardous heavy metal in the soil.Results and Discussion  According to the results, the concentration of Pb and Cd in  shoots of atriplex  area 2 (with an average of 19.7 and 5.75 mg/kg, respectively) were significantly higher than in other areas, while the concentration of these metals in root of oleander (with an average of 8.17 and 1.06 for Pb and Cd, respectively) were higher than the shoot. The amount of Pb element in soil of the oleander plant (with an average of 35.13 mg/kg) and Cd in soil of the atriplex area 2 (with an average of 3.78 mg/kg) were significantly higher than other areas. Additionally, the levels of heavy metals in the soil of two plants were higher than the Nemerow index, which indicated high levels of pollution in the sampling areas, but still below the safe levels that was set by national standards (3.9 and 300 mg/kg for Cd and Pb respectively) and the World Health Organization (5 and 40 mg/kg for Cd and Pb, respectively). In addition, bioaccumulation factor of shoot in all growth atriplex areas for Pb and Cd (with an average of 1.44 and 1.3, respectively) were higher than 1.0 while, the root bioaccumulation factors of this plant in any of the growth areas, were not higher than 1.0. In the case of oleander, the shoot and root bioconcentration factors  for Pb and Cd were not reported more than one.   Conclusion In general, it appears that atriplex, a native plant in the Aradkooh landfill, exhibits superior capabilities for absorbing heavy elements compared to oleander. Therefore, atriplex seems well-suited for the extraction of Pb and Cd from the soil, as it can accumulate these metals in its shoots. In contrast, oleander is not well-suited for phytostabilization or phytoextraction of these elements, as it exhibits limited ability to accumulate these heavy metals in its roots and shoots. Consequently, atriplex can be a valuable choice as a resilient species for phytoremediation projects in landfills and areas near mines. It is worth noting that the Pb content in the soil is higher than that of Cd. Although both metals fall within the permissible limits of national and WHO standards, the soil in the Aradkooh landfill is considered to be significantly polluted based on the Nemerow index

Mass rearing of the larvae of Chironomus riparius (Dip.: Chironomidae)

Aquatic larvae of chironomid midge, Chironomus riparius Meigen, are one of the richest diets in fish rearing systems. The quantity and quality of food used to rearing these larvae, affect this developmental stage. This study was conducted to determine the effect of different diets (chicken manure, rice bran and soybean meal) with different weights (1, 3 and 5 gr) on larval development, the best time of harvesting at different constant temperatures (16-20, 22 ± 1, 24 ± 1, 26 ± 1, 28 ± 1 and 30 ± 1 oC) and the yield (larval live weight (gr) m-2 per week) based on the number of reared egg masses with the favorable diet. Results indicated that the highest weight of harvested larvae obtained when they fed on 5 gr of chicken manure (3.53 ï± 0.4, p < 0.01). The last larval instars were harvested at the shortest time (on 13th days), when reared at 24 ± 1 or 26 ± 1 oC feeding on chicken manure (compared to other temperatures). Mean yield of 131.38 ï± 13.99 gr m-2 per week obtained, when five egg masses were reared at 26 ± 1 oC on the chicken manure

Prediction of rock strength parameters for an Iranian oil field using neuro-fuzzy method

Uniaxial compressive strength (UCS) and internal friction coefficient (µ) are the most important strength parameters of rock. They could be determined either by laboratory tests or from empirical correlations. The laboratory analysis sometimes is not possible for many reasons. On the other hand, Due to changes in rock compositions and properties, none of the correlations could be applied as an exact universal correlation. In such conditions, the artificial intelligence could be an appropriate candidate method for estimation of the strength parameters. In this study, the Adaptive Neuro-Fuzzy Inference System (ANFIS) which is one of the artificial intelligence techniques was used as dominant tool to predict the strength parameters in one of the Iranian southwest oil fields. A total of 655 data sets (including depth, compressional wave velocity and density data) were used. 436 and 219 data sets were randomly selected among the data for constructing and verification of the intelligent model, respectively. To evaluate the performance of the model, root mean square error (RMSE) and correlation coefficient (R2) between the reported values from the drilling site and estimated values was computed. A comparison between the RMSE of the proposed model and recently intelligent models shows that the proposed model is more accurate than others. Acceptable accuracy and using conventional well logging data are the highlight advantages of the proposed intelligent model