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Multi-walled carbon nanotubes (MWCNTs) were functionalized by monoethanolamine (MEA), diethanolamine (DEA) and triethanolamine (TEA) by a rapid microwave-assisted method. Surface functional groups and morphology of MWCNTs were analyzed by ultraviolet-visible spectroscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, Raman spectroscopy and transmission electron microscopy. The water dispersibility of samples was also measured over time and compared with that of MWCNT functionalized by ethylenediamine (EDA). Accordingly, the dispersibility was in the sequence MEA-MWCNTs > DEA-MWCNTs > TEA-MWCNTs > EDA-MWCNTs > pristine MWCNTs. The significant long-term dispersibility of MEA-MWCNTs was related to its exceptionally high surface functionalization (89.3 %) and lack of chemical bridging between adjacent MWCNTs. This strategy, along with the low-cost functionalizing agents, could pave the way for large-scale dispersion of CNTs in the polar solvents. [ABSTRACT FROM AUTHOR]

Background: For the treatment of bone defects that exceed the critical size of the injury, several therapies have been investigated. Thermal decomposition method is suggested for extraction of natural hydroxyapatite bioceramic (HA). This technique in comparison with other methods of producing HA, has less complexity and greater economic efficiency. Objective: In the present study, a thermal decomposition method is suggested for extraction of natural HA from bovine femur bones. Methods: In this experiment, to extract the ceramic material, the bone samples were first de-fatted and ground to particles less than 420 μm, and also 420-500 μm, respectively. Prepared powders were heated at 170 °C for 24 h, and then divided into two groups for 6 h. The first group was heated at 750 °C; the second group was heated at 850 °C. The calcium phosphate compounds were obtained with complete elimination of the organic phase of the bone. These bioceramic compounds were characterized physiochemically by X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), energy dispersive X-ray (EDX), and scanning electron microscopy (SEM). Results: We found that the powder heated at 750 °C in two dimensional scales was rich in carbonated hydroxyapatite, and therefore, eminently suitable for using in hard tissue replacements. However, increasing the temperature up to 850 °C reduced the Ca/P ratio to 1.5 in the powder sample sizes less than 420 μm. Consequently, the obtained composition became rather similar to the chemical formula of tricalcium phosphate (TCP) that is appropriate in tissue engineering and drug delivery applications. Conclusion: The observations affirmed that by eliminating the collagen and other organic materials existing in the bovine bones, the mineral phase of the bone had the potential of transformation to nanoparticles. To investigate the repair of critical-size bone defects and bone augmentation, cylindrical blocks were fabricated by applying different pressures of 150, 160 and 170 MPa. The structure and compressive strength of the pressed samples after sintering at 1200 °C were characterized by SEM and compressive strength test. [ABSTRACT FROM AUTHOR]

This paper is a narration of gel generator technology development and adoption in lran including production of 99Mo by neutronactivation of molybdenum [98>Mo(n, γ)99Mo] in the research reactor of Tehran. The indigenous design and development of units for the manufacturing of gel generators included the setting up of shielded plant facilities with pneumatic-driven as well as manual controls and special gadgets, process adaptation to automation in the shielded facility, regulatory clearances and commencement of operations for periodic production of gel generators, demonstration of clinical utility, and adaptation of the generator design. Molybdenum-99 is being converted to zirconium molybdate gel under controlled conditions, and the resulting gel is dried at three steps, which include 2 h at 100°C, 2 h at 90°C, and 5 h at 70°C in order to reduce the time period between the end of reactor irradiation and completion of the processing of gel generators. The produced sodium pertechnetate solution from these gel-type 99Mo/99mTC generators fulfills all requirements of U.S. pharmacopeia. All the generators provide high-yield and pure elutions as well as sterile and pyrogen-free pertechnetate solution. In addition, it shows favorable-quality features to prepare various 99mTC complexes. [ABSTRACT FROM AUTHOR]

Background: Pediculus capitis or head louse infestation affects millions of children worldwide, especially those in the 5-11 years age group. This study aimed to determine the prevalence of head pediculosis among school children in urban and rural areas of Fars Province, southern Iran. Methods: All school children of age 6-11 yr from both genders in all urban and rural areas of the province were screened for head louse infestation by examination of their hair and scalps. Parents of all infested children were also examined. The study was repeated in different seasons in the same areas. Moreover, infested children were treated with 5% permethrin shampoo and re-examined one week later for any relapse. Results: The general prevalence of head louse infestation in primary school students was 0.49% in autumn, 0.37% in winter and 0.20% in spring. In the mentioned seasons, the prevalence of P. capitis was higher among females and in rural areas (P=0.001). Although treatment with permethrin shampoo failed in females, it was successful in all infected males from both regions in autumn and spring and in males from urban areas in winter. Conclusion: Head louse infestation is uncommon among Fars Province school children in rural and urban areas and should not be considered a public health priority. However, due to the higher prevalence of pediculosis in low socioeconomic group and rural area in our region, it seems that health promotion, particularly early detection and effective management strategies should target this group in the province. [ABSTRACT FROM AUTHOR]

This experimental study was conducted to investigate the effects of different opening ranges of waste-gate of a turbo-charged DI diesel engine on improving the exhaust soot emission. Different opening ranges of waste-gate were supplied using an adjustable spring to load the actuating rod of the waste-gate in which, increasing the opening range of the waste-gate decreases the inlet manifold pressure. In this study, the maximum inlet manifold pressures which were supplied by changing the opening range of waste-gate were 0.1bar, 0.23bar, 0.26bar and 0.52bar over atmosphere and experiments were conducted under the ECE-R49, 13 mode standard test. At each mode of the test, soot emission was recorded and then brake specific soot emission was calculated. Results indicate that, soot emission decreases with increasing the maximum inlet manifold pressure from 0.1bar to 0.23bar. This reduction may be due to increasing the intake-air temperature which results in reduction of ignition delay that prolongs the late combustion phase. This improves the soot burnout process because enough time and sufficient in-cylinder temperature are available at the late combustion phase prior to exhaust valve opening. While for the higher maximum inlet manifold pressures from 0.23bar to 0.52bar, although there are enough time at the late combustion phase, but the soot emission increases which could be due to more reduction of the in-cylinder gas temperature at the end of combustion before EVO. [Copyright &y& Elsevier]

Mal-operation of distance protection relays during power swing (PS) condition can endanger the power system stability. Therefore, it is crucial to distinguish between short-circuit faults and PS by a power swing blocking (PSB) function to prevent undesired tripping of distance relay. This paper develops a novel and straightforward PSB method based on the rate of impedance angle change (RIAC). Not only can the proposed approach fairly discriminate both symmetrical and asymmetrical faults from PS, but also it can appropriately preserve protection scheme security during PS under single-pole tripping (SPT) on a transmission line. Furthermore, there is no need to perform extensive dynamic stability studies for setting the PSB function parameters. Unlike the rate of impedance change approaches utilized two blinders, the developed approach only needs an inner blinder. Thus, it can be used for networks running near their operational limits. The proposed method is evaluated through a modified IEEE-PSRC benchmark system in PSCAD/EMTC environment. The obtained results verify superior performance of the proposed method to traditional impedance rate of change method under different scenarios. [ABSTRACT FROM AUTHOR]

In this work, exchange radioiodination of metaiodobenzylguanidine (MIBG) was carried out at optimum conditions that facilitates the production of [131I]MIBG both quickly and efficiently. The radiochemical purity and yield of the labeled product are typically as high as 99% and 90% for diagnostic dose and 95% and 80% for therapeutic dose, respectively. Stability studies show that labeled material at the room temperature met the demand of the clinical application. This labeling procedure will be used in the routine production process of [131I]MIBG for diagnosis and treatment uses. [ABSTRACT FROM AUTHOR]

• This paper develops a new method for optimal placement of power system stabilizers (PSSs) and tuning them simultaneously in the multi-machine system. • This method is based on an improved genetic algorithm (GA), and the power system model is very accurate. • The main contributions of the paper include: • Developing a high-order model for generators and investigating its effect on PSS tuning. • Explanation of a simultaneous locating and adjustment framework for PSS shows its superiority over the SMIB method and other algorithms such as; GA and PSO. This paper introduces a new method for optimal placement of power system stabilizers (PSS) and tuning them simultaneously in the multi-machine system. This method is based on an improved genetic algorithm (GA), and the power system model is very accurate. This method determines the best place to install the stabilizers, using the least number of PSS and tuning their parameters simultaneously to move the poles to the left of the imaginary axis and maximize the damping ratio of mechanical modes. In addition, the proposed algorithm can consider any of the critical conditions, which are obtained based on sensitivity analysis, and suggest a robust setting for stabilizers. After implementing the proposed algorithm in MATLAB, the modal analysis and time-domain simulations in IEEE 9Bus and IEEE 39Bus systems were compared with other algorithms. The results confirm that the proposed algorithm can effectively improve dynamic stability margin. [ABSTRACT FROM AUTHOR]

Let M be a normal subgroup of a finite group G such that |G/M| = pm and |M/Z(M,G)| = pn. In this paper, we characterize all the pairs of groups (M,G) which satisfy the conditions and |[M/Z(M,G),G/Z(M,G)]|≤ p. If M has a complement in G and |M|=pn and |G/M|=pm, then there always exists a non-negative integer t(M,G) such that . Under some conditions, we determine all the pairs (M,G) with t(M,G)=0, 1 or 2. [ABSTRACT FROM AUTHOR]

Derivative-based approaches have been used both in the literature and in the industry to identify fault current distortions caused by current transformer (CT) saturation. This study presents a new simple, but efficient, derivative-based technique to detect CT saturation. First a difference function for the samples on the two sides of the current local extremum is defined. Based on the values of this difference function for various current samples, a variance function is defined. By comparing this variance function with a pair of pre-set thresholds, CT saturation can be determined. This technique is not affected by CT parameters such as CT burden, core remanence or magnetisation curve. The independence of this method from the fault current characteristics, such as decaying DC time constant, noise and so on, is investigated. Numerous simulations were carried out using PSCAD/EMTDC program. The performance of this algorithm for simulated fault currents together with a set of experimental results verify the accurate operation of the proposed method for different conditions including mild and fast CT saturations. [ABSTRACT FROM AUTHOR]

Much attention has recently been paid to natural language processing in information storage and retrieval. This paper describes how the application of natural language processing (NLP) techniques can enhance cross-language information retrieval (CLIR). Using a semi-experimental technique, we took Farsi queries to retrieve relevant documents in English. For translating Persian queries, we used a bilingual machine-readable dictionary. NLP techniques such as tokenization, morphological analysis and part of speech tagging were used in pre-and- post translation phases. Results showed that applying NLP techniques yields more effective CLIR performance. [ABSTRACT FROM AUTHOR]

Background and the purpose of the study: Following the phase I clinical trial of the herbal drug IMOD™ in HIV/AIDS patients, further studies were required to assess the drug efficacy and side effects. Therefore its safety and efficacy in HIV infected patients in a phase II were examined, and clinical trial phase III were designed. Methods: This study was conducted in three stages. In the first stage six patients who were resistant to highly active anti retroviral therapy (HAART) regimen were chosen and offered therapy with Setarud. Subsequently another group of 27 patients with CD4 count less than 350 but without AIDS defining criteria were enrolled to the study and randomly assigned to intervention. In the third stage a double-center randomized clinical trial was conducted at two independent research centers and universities of Iran. Seventy patients were recruited and randomly allocated into groups, called "control" and Setarud groups, using a balanced block randomization method. The main outcome measure was CD4 count. Patients were observed and thoroughly examined (Clinical and laboratory) for six months. Results: In stages I and II, the mean CD4 count gradually increased within 3 and 6 months intervals. In the stage III the baseline of CD4 counts and other characteristics between two groups were quite similar. The mean increase in CD4 count in Setarud group was about 2-3 fold higher than controls. This effect was much more pronounced in a subgroup of patients with a baseline CD4 count of 200-400 (168 vs. 65, 203 vs. 58, 299 vs. 143 and 285 vs. 109, for time intervals of follow-up, respectively) (p<0.001). Conclusion: There was a significant improvement in the immune system of HIV patients receiving Setarud therapy by increase in the CD4 count to the higher and more protective level in most subjects. Considering results of the safety tests and reports of the durability of the Setarud effects the use this drug in HIV patients, especially at the pre-AIDS period, as a therapeutic vaccine to slow down the progression of the disease, is recommended. [ABSTRACT FROM AUTHOR]

Twenty patients with large endodontic lesions, which failed to respond to conventional endodontic therapy, were selected for this study. The lesions had a radiographic diameter of at least 10mm, were removed by periradicular surgery, before retrofilling the apices with either super EBA or dessicated zinc oxide-eugenol. In 10 test sites large e-PTFE membranes (Gortex) were placed to cover the lesions., while at the control sites the lesions were not covered before resuturing. Radiographic analysis of the lesions at 3, 6, 9 and 12 months revealed that lesions covered with the membranes healed quicker than the. control lesions., and that the quality and quantity of the regenerated bone was superior when membranes were used, Results of the study indicate that guided tissue regeneration (GTR) principles can be effectively applied to the healing of Jarge periapical lesions, especially in through-and-through lesions. [ABSTRACT FROM AUTHOR]