110 research outputs found

    Design and implementation of location-based service for targeted advertising

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    Nowadays, mobile phones have been increasingly advertised. These performance advertisement tools altered to be one of the beneficial factors in order to promote products and services in national or local companies. One of the outstanding features of mobile phones is that everybody has accessibility in different circumstances and times. Companies struggle to draw customers attention by providing information, stimulating text or image to advertise their products by which high cost have been consumed. In this study, a system is designed and implemented for efficient and effective interaction between companies and customers. It is worth mentioning here this system has some great feature like being aware of text, owning mobile user Interface and presenting location-based service. These features enable companies to design an advertisement in a purposeful way. Such these advertisements can effectively be sent to the population company which are on target. Finally, the system was evaluated. Reduction in cost and effectiveness of advertising are grounded in the result of the study

    Iron catalyst supported on carbon nanotubes for Fischer-Tropsch synthesis : experimental and kinetic study

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    The main objectives of the present Ph.D. thesis are comprehensive studies on activity, selectivity and stability of iron catalysts supported on carbon nanotubes (CNTs) for Fischer-Tropsch (FT) reactions. In order to prepare iron catalyst supported on CNTs, it was necessary to study CNT synthesis in bulk scale. Therefore, a part of this research was devoted to the production and characterization of CNTs. High purity, aligned films of multi-walled carbon nanotubes were grown on quartz substrates by feeding a solution of ferrocene in toluene, in a carrier gas of Ar/H2, into a horizontal chemical vapour deposition (CVD) reactor. Results for CNTs synthesized using a wide range of toluene concentrations indicated that, for carbon concentrations higher than ~9.6 mol/m3, catalyst deactivation occurs due to encapsulation of iron metal particles. As the first step of catalyst development for FT reactions a fixed bed micro-reactor system was built and the effects of acid treatment on the activity, product selectivity and stability of iron Fischer-Tropsch catalysts supported on carbon nanotubes were studied. The results of Raman analysis showed that the acid treatment increased the number of functional groups as anchoring sites for metal particles. Fe catalysts supported on CNTs which were pre-treated with nitric acid at 110°C were more stable and active compared to the un-treated catalysts. In order to study the effects of catalytic metal site position on FT reactions, a method was developed to control the position of the deposited metal clusters on either the inner or outer surfaces of the CNTs. According to the results of the FT experiments, the catalyst with catalytic metal sites inside the pores exhibited higher selectivity (C5+ = 36 wt%) to heavier hydrocarbons compared to one with sites on the outer surfaces (C5+ = 24 wt%) . In addition, deposition of catalytic sites on the interior surfaces of the nanotubes resulted in a more stable catalyst. The effects of pore diameter and structure of iron catalysts supported on CNTs on Fischer-Tropsch reaction rates and selectivities were also studied. In order to examine the effects of pore diameter, two types of CNTs with similar surface areas and different average pore sizes (12 and 63 nm) were prepared. It was found that the deposition of metal particles on the CNT with narrow pore size (in the range of larger than 10-15 nm) resulted in more active and selective catalyst due to higher degree of reduction and higher metal dispersion. Promotion of the iron catalyst supported on CNTs with Molybdinium in the range of 0.5-1 wt % resulted in a more stable catalyst. Mo improves the stability of the iron catalyst by preventing the metal site agglomeration. Promotion of the iron catalysts with potassium increased the activity of FT and water-gas-shift reactions and the average molecular weight of the hydrocarbon products. Promotion of the iron catalyst supported on CNTs with 0.5% Cu and 1wt% K resulted in an active (5.6 mg HC/g-Fe.h), stable and selective catalyst (C5+ selectivity of 76%) which exhibited higher activity and better selectivity compared to the similar catalysts reported in the literature. Kinetic studies were conducted to evaluate reaction rate parameters using the developed potassium and copper promoted catalyst. It was found that the CO2 inhibition is not significant for FT reactions. On the other hand, water effects and presence of vacant sites should be considered in the kinetic models. A first-order reaction model verified that the iron catalyst supported on CNTs is more active than precipitated and commercial catalysts. The results of the present Ph.D. thesis research provide a map for designing catalysts using carbon nanotubes as a support. The key messages of the present thesis are as follows: 1- If the interaction of the metal site and support is strong, which poses negative effects on the catalytic performance, carbon nanotubes can be one solution. 2- Acid pre-treatments are required prior to impregnating nanotubes with metal salt solution. Also, the strong acid treatment should be used for deposition of catalytic sites inside the pores of nanotubes. 3- The structure and pore size of nanotubes have significant influence on the stability, activity and selectivity of the target catalyst. 4- The position of the catalytic sites has to be selected based on the type of reaction. In the case of Fischer-Tropsch reactions, the deposition of catalytic sites inside the pores of nanotubes results in higher activity, longer life span. The outcome of this Ph.D. thesis has been published/submitted in the form of 13 journal papers, one patent, one technical report and presented at 11 conferences

    Volunteered geographic information in crisis management

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    During the disaster, rescue groups are responsible for tasks that require different types of information to optimize their activities. Preparation and distribution of information are very sensitive. The acquisition of new data and events such as degraded buildings and injured people in some cases using conventional methods is very difficult. With the advancement of technology, people familiar with social networks and smartphones, people produce and generate large amounts of data. This phenomenon is called Volunteered geographic information. Today, this data collected and shared with sites and social networks for free. This paper pays service that Volunteered geographic information provided to crisis management. Experience has shown that the system cannot work without regard to environmental considerations. The current system of data collection, updating and spatial data infrastructure, cannot consider emergency situations. In particular, companies such as Ushahidi and OSM's activities will be described. This article is based on articles and activities conducted in this field and provides the category and in the end, discussed and determine the factors affecting the performance of them

    The Study and Analysis of Verbal Thoughts of Attar Neishabouri (Looking at his Masnavi)

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    The influence of theology and verbal thoughts in Persian literature is an undeniable issue, so we can observe the majority of verbal subjects in mystical works. In this study, we consider verbal scopes of Attar in his Masnavi including verbal theism and belief in behavioral determinism and wisdom dysfunction. In the conception of narrative virtue, indecency, absolute purity, and divine grace and resurrection are the most important verbal concepts of Attar in Masnavi. But it is noticeable that Attar did not accept different verbal thoughts absolutely. In other words, Attar's perspectives incorporated gnostic scopes and verbal theories. For example, in the field of theism, he believed in a beloved, lovable, and kind God while most poets knew his wrathful and unmerciful features that whatever he does is mere justice. Generally, it could be said that although Attar had the same views as other poets, in some cases, one can see ideas different from the other poets’ ideas in his works

    Assessing growth parameters of children with congenital hypothyroidism subject to levothyroxine treatment compared to normal growth parameters in healthy newborns

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    Background and aims: Congenital hypothyroidism (CH) is one of the most common treatable physical growth disorders leading to mental retardation. Most cases of this disease can be detected through the neonatal screening program. Given the high prevalence of this disease and the implementation of screening programs in recent years in Iran, this study aimed to assess the growth indices of newborns with CH. Methods: In this retrospective cohort study, 66 newborns with CH detected in the screening program in Shahrekord were selected by a census sampling method. Overall, 125 healthy newborns were also selected as controls by the convenience sampling technique according to the inclusion and exclusion criteria. The height, weight, head circumference, and body mass index (BMI) of the samples were measured and then the mean, median, standard deviation, as well as the 3rd, 15th, 25th, 50th, 75th, 85th, and 97th percentiles in the two groups were determined and compared based on gender and age group. Results: The height, weight, head circumference, and BMI of the boys, in addition to the head circumference and BMI of the girls, were not significantly different from those of the controls (P>0.05). However, the height and weight of the girls were significantly lower compared to those in the control group, although the difference in the weight was corrected at the age of 9 months. Conclusion: In general, the growth indices of newborns with CH were lower than those of the controls. This difference was significant only for the weight and height of girls with CH. Keywords: Congenital hypothyroidism, Growth indices, Newborn Screenin

    Optimal SSSC-based power damping inter-area oscillations using firefly and harmony search algorithms

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    The static synchronous series compensator (SSSC) can add a series reactance to the transmission line, and when it is fed using auxiliary signals, it can participate in damping inter-area oscillations by changing the series reactance. In this paper, the effect of the SSSC on small-signal stability is investigated. The design of a controller for damping oscillations is designed and discussed. Moreover, using the firefly and the harmony search algorithms, the optimal parameters controlling SSSC are addressed. The effectiveness of these two algorithms and the rate of SSSC participation in damping inter-area oscillation are also discussed. MATLAB software was used to analyse the models and to perform simulations in the time domain. The simulation results on the sample system, in two areas, indicated the optimal accuracy and precision of the proposed controller

    Predictive Value of Absent Septal q Wave in Patients with Significant Stenosis of Proximal Left Anterior Descending Coronary Artery

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    Aims: There is conflicting data about the predictive value of absent septal q wave in patients with significant stenosis of proximal Left Anterior Descending coronary artery. To clarify the exact role of this simple electrocardiographic sign we conducted this prospective descriptive study. Methods: Patients who were referred for coronary angiography in Milad Hospital between December 2008 and September 2009 were chosen randomly. Standard ECG was performed and reviewed for presence or absence of septal q wave, and then the coronary angiography was done and reported by another cardiologist. Results: Of 148 patients with absent septal q wave in ECG, 85 patients (57%) had significant stenosis of proximal LAD in coronary angiography. Statistical analysis showed that significant stenosis of proximal LAD could be predicted by absence of septal q wave in ECG with sensitivity of 59% and specificity of 47%. However, Kappa statistic (Kappa = 0.36) showed low agreement between them. Conclusion: Absence of normal septal q wave in ECG could be a low value predictor of coronary artery disease mainly significant proximal LAD stenosis

    Association between splenectomy and pulmonary hypertension in patients with major beta- thalassemia

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    Background and purpose: Increased pressure in the pulmonary circulation is of the major factors causing cardiac disorders in patients with thalassemia. The aim of this study was to investigate the relationship between splenectomy and pulmonary arterial pressure in individuals with beta- thalassemia major. Materials and methods: A cross-sectional study was carried out in patients with beta-thalassemia attending Hajar Hospital Shahrekord, Iran, 2015. All patients underwent echocardiography and the hemoglobin levels, platelet count, ferritin, pressure, pulmonary arterial pressure, etc. were measured. Data analysis was done in Stata 13. Results: Among the variables measured, the average age, hemoglobin level, platelet count, nucleated RBC, lactate dehydrogenase, tricuspid regurgitation flow, pulmonary arterial pressure, right diameter, main pulmonary diameter, left ventricular end diastolic diameter, left ventricular end systolic diameter were found to be higher in patients with splenectomy, compared to those of the patients without splenectomy (P> 0.05). Significant correlation was observed between platelets, NRBC and the time of splenectomy with pulmonary artery pressure (P 0.05). Conclusion: The results showed that splenectomy could increase the susceptibility to pulmonary artery pressure in patients with beta thalassemia major or lead to the progression of pulmonary hypertension in this disease
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