Manganese ore is widely used in many industries. Such as ore contain natural radioactive nuclides at various concentrations. If this ore contain high concentrations of natural radioactive nuclides, workers handling them might be exposed to significant levels of radiation. Therefore it is important to determine the radioactive nuclides in this ore. Also the regulation of radon concentration at workplaces has gained an accentuated importance in all countries. Nevertheless, at this time there is no globally accepted workplace protocol that sets out safe radon concentration values. In this study the radon concentration measured by using an Alpha Guard radon monitor, the equilibrium factor which was greater than the value given in literature, effective radiation dose, which are necessary for the exact estimation of the radiation dose originating from radon. The regulation of radon concentration at workplaces has gained an accentuated importance in all countries. Approach: The natural radionuclides (238U, 232Th and 40K) contents of manganese ore samples collected from Umm Bogma, southwest Sinai and from the mountain access Hamid South Eastern Desert, Egypt have been determined by low background spectroscopy using hyper-pure germanium (HPGe) detector. Results: The mean activities due to the three radionuclides (238U, 232Th and40K) were found to be 1500±65, 490±65 and 364±45 Bqkg-1, respectively. The absorbed dose rate due to the natural radioactivity in samples under investigation ranged from 1522±45 → 1796±43 nGyh-1. The radium equivalent activity varied from 3807±114→ 4446±133 Bqkg-1.The representative external hazard index values for the corresponding samples are also estimated. Conclusion: The results of this assessment obtained by the gamma-ray spectroscopic analysis, have indicated that the levels of natural radioactivity were lower than the international recommended limits.
In the present work, a novel configuration of solar-powered desiccant dehumidification system is demonstrated. A rotating wick made of double layered cotton-cloth has been applied as a desiccant solar regenerator. The blackened wick-surface, which is impregnated with calcium chloride solution, moves between two rotating pulleys at an inclination angle of 20 degrees. Solar radiation incident on the wick surface regenerates the liquid desiccant in the wick. In the experimental study, instantaneous values of the desiccant solution concentration is evaluated and recorded with time. Apparent values of system coefficient of performance around 2 could be attained in the dry climate of Taif city. Instantaneous as well as average values of mass transfer coefficient are evaluated from the experimental measurements. System operational problems are discussed and highlighted.
In this paper, we study timelike Smarandache curves according to Bishop frame in Minkowski 3-space and we give differential geometric properties of these curves.
The purpose of this paper is to prove a general form of a fixed point theorem with contractive-like mapping defined by altering function. We also present its application on study of existence and uniqueness of solution of fuzzy initial value problems.
Antioxidants are vital substances which possess the ability to protect the body from damage caused by free radical induced oxidative stress. A variety of free radical scavenging antioxidants exist within the body. Many of them are derived from dietary sources like fruits, vegetables and herbs. The antioxidant activity and radical scavenging activity of water extracts of Truffle claveryi, traditionally used by King Saudi Arabia population as folk remedies, were evaluated against linoleic acid peroxidation and 2,2diphenyl-1-picrylhydrazyl radical. In current study the antimicrobial activity of Truffle claveryi against (Gram-positive bacteria and Gram-negative bacteria) were tested. The data showed the highest affect of Pseudomonas aeruginosa reached to 23 mm inhibition zone compared with reference antibiotics. Thus, the minimum inhibitory concentration (MIC) of Truffle claveryi towards pathogens Pseudomonas aeruginosa were examined in this study. Then, a phytochemical screening was realized for the extracts. Our results showed that Truffle claveryi has high, antioxidant activity, total phenolic content. and antimicrobial activity.
Loss minimization in a power system is an important research issue. Also for the last two decades, voltage stability is a major concern in planning and operations of power system. This has been mainly due to power systems being operated closer to their stability limits because of increased demand for electricity. The use of Flexible AC Transmission Systems (FACTS) technology improves the Stability also reduces the losses in the Power System. Identification of the optimal location and Operating requirement of FACTS devices like SVC, TCSC and UPFC is an important need in the power system. This will help to maintain bus voltages at a desired level and also to improve the Voltage Stability margins. This paper presents an application of Genetic Algorithm and Particle Swarm Optimization in identifying the optimal location and operating requirement of different FACTS devices. The proposed approach has been evaluated with two different objective functions namely loss minimization and voltage stability enhancement. The IEEE 14 bus, IEEE 30 bus and IEEE 57 bus systems are used as test systems to demonstrate the applicability and efficiency of the proposed system. Both the results from GA and PSO are compared and the test result shows that PSO is more effective than GA.
Palm oil industry is one of the major agro-industries in Thailand. Fresh fruit bunches (FFB) is supplied to the industry and a large amounts of palm oil residue is produced in the milling process. Although grate fired furnace have been used over many years, the design and operating conditions are not fully optimised yet. There are still some problems that are encountered and improvements needed, including the effectiveness of the fuel bed combustion and mixing in both the fuel bed and in the freeboard. The chemical species leaving the bed and entering the freeboard depend completely on the reaction inside the fuel bed. Therefore, a reliable bed model is a prerequisite for a good model of a grate fired furnace. This paper deals with bed combustion simulation of palm oil residue on a grate fired furnace. Numerical models have been developed and employed to simulate the operation of palm oil residue bed combustion to obtain detailed information on the gas flow and combustion characteristics in the bed furnace. The grate fired furnace under this study consists of pushing-grate with 8.6 m length, 5.4 m width and 26º incline and is operated at a capacity of 12.9 t/h. Under-fired air is supplied from the bottom of the grate. The performance of this method is demonstrated and discussed based on the outputs of the simulation tests. The results from this study greatly help to understand the operating characteristics of large-scale palm oil residue grate fired furnace
This paper proposes the use of series FACTS devices to relieve congestion and enhance the security in restructured power system. Harmony search algorithm as a novel heuristic algorithm is employed for optimal locating and sizing of series FACTS devices. In order to reduce the solution space and to pinpoint the lines which are more suitable for FACTS device placement line outage sensitivity factors is employed. Two different objective functions are considered in the optimization problem, the first one is the total congestion cost and the other is total generation cost. To validate the effectiveness of the proposed method and show its efficiency, the simulations are carried out on IEEE 14-bus test system. The results of the proposed method are compared with those obtained by particle swarm optimization and with those obtained by congestion rent contribution method.
In this paper, we use new notation of fuzzy numbers and convert\na fuzzy linear system (FLS) to two linear system in crisp case for solving FLS also we are discussed complexity of proposed method. Conditions for the existence of a unique fuzzy solution to $n\\times n$ fuzzy linear system are derived and a numerical procedure for calculating the solution is designed. Also several well-known numerical methods for solving system of linear equations such as Jacobi and Gauss-Seidel are extended for solving FLS. The iterative methods are followed by convergence theorems. Numerical examples are presented to illustrate the proposed model.
The purpose of this paper was to develop the impulsive buying scale for Iranian customers. Analysis of the data,utilizing LISREL 8.8 from 337 consumers in shopping centers. Results developed a four factor scale for Iranian buying impulsiveness. It included felt urge to buy impulsively, prudence, hedonic shopping and impulsive buying tendency. This study added valuable empirical findings to the literature on the different types of buying. This study provided insights for customer impulse buying behavior in Iran shopping environments.\nFor developing a new buying impulsiveness scale, exploratory and confirmatory factor analysis were used. To assess the construct and content validity of the items, data from the impulsiveness scale were factor analyzed.
Enterobacter aerogenes TISTR1468 was used for ethanol production from crude glycerol in batch experiment. Effect of initial substrate concentration on the rate of ethanol formation was studied in a 3 L bioreactor with 0.5 vvm aeration rate and 60 rpm agitation speed. The rate of ethanol formation increased with the increase of glycerol concentration up to 50 g/L and decreased thereafter. A kinetic model describing the rate of substrate utilization and inhibition was developed. The maximum specific growth rate (μm) was 0.28 h−1 with the substrate saturation constant (Ks) of 5.60 g/L and the substrate inhibition constant (KI) of 61.2 g/L. The maximum value of substrate consumption rate was 2.34 gglycerol/L/h whereas ethanol production rate and ethanol yield were 1.00 gethanol/L/h and 0.52 gethanol/gglycerol, respectively.
This study examined to compare high-yielding cultivars and respond to N fertilization especially yield component and the aim of this development of rice cultivars suitable for low input requires. Experiment was arranged in a randomized complete block design with a split plotarrangement of five rice cultivars, three N rates with four replications in 2011 in Iran. N rates including 0, 69, and 138 kg N ha–1 as (N0), (N69) and (N138) and rice cultivars including Nemat (C1), Khazar(C2), Neda (C3), Shirodi (C4) and Tarom (C5). The results indicated that all traits response to cultivar and N rates were detected for the parameters examined. The lowest applied N rate had lower yield than the other two N rates. Grain yields were 5552 for 69 kg N ha–1 and 6124 for 134 kg N ha–1 averaged over all cultivars. Grain yield of Khazar and Tarom was independent of N rate, but grain yield of Nemat, Neda and Shirodi increased when the N rate was increased from 67 to 138 kg ha–1. Panicle density responded to N rate similar to grain yield. Khazar produced more total spikelet number while Neda had a higher Panicle density. Grain yield and yield components of Nemat, Neda and Shirodi respond to N rates dependently when planted into high nitrogen. Finally, modern rice cultivars were more efficient at recovering N than older cultivars.
Within the framework of contrastive rhetoric, the present research focused on the study of the\nexistence of cross-cultural differences in rhetorical terms between the expository essays\nwritten by Persian EFL writers and the English preferred style. Two rhetorical features were\nexamined including: deductivity and linearity in the five paragraph expository essays written\nby Persian EFL writers. The material in this study consisted of (1) the expository essays\nwritten by 110 students from 6 universities in Iran, (2) two analytic scoring scales developed\nand validated by the researcher, and (3) Internet-based version of the TOEFL test data\n(TOEFL iBT) for 2009. The findings of this research lend support to the general conclusions\nof the other contrastive rhetoric studies in Iran about the existence of cross-cultural\ndifferences in rhetorical terms between the Persian and western preferred styles.\nKeywords: culture, essay, paragraph, contrastive rhetoric, deductivity, linearity, writer\nresponsible
In recent years, reversible logic has emerged as a promising computing paradigm having application in low power CMOS, quantum computing, nanotechnology, and optical computing. Increasing demand for power reduction in computer systems has led to new trends in computations and computer design including reversible computing. Its main aim is to eliminate power dissipation in logical elements but can have some other advantages such as data security and error prevention. Because of interesting properties of reversible computing, implementing computing devices with reversible manner is the only way to make the reversible computing a reality. A gate is reversible if it has the equal number of inputs and outputs and in addition has one-to-one mapping between inputs and outputs. In the reversible gates there is a distinct output assignment for each distinct input. Therefore, the inputs of a reversible gate can be uniquely reproduced from the outputs. In this paper, we propose and realize a novel implementation of CNOT gate in all-optical domain. We have explained its principle of operations and described an actual experimental implementation. The all-optical reversible gate presented in this paper will be useful in different applications such as arithmetic and logical operations in the domain of reversible logic-based computing.
Escherichia coli is one of the most important species in the Escherichia genus. In the recent years hemorrhagic Colitis has been associated with au strain called E. coli O157:H7 and this strain is known as causative agent of bloody diarrhea and predominant cause of hemolytic uremic syndrome (HUS). The main objective of present study was to prevent of E.coli O157:H7 infection both directly and indirectly by using of L.plantarum and L.casei isolated from Ligvan cheese as single and combined use. In this study 40 mice of 6-8 weeks old were divided into 4 groups of 10 mice by chance. Stool of mice studied for recovery of E. coli O157:H7 before getting infected and on days 3,5 and 7 after getting infected with the test organism. For identification of E. coli O157:H7 MacConkey sorbitol agar was used and for confirmation of the diagnosis specific antiserum against E. coli O157 was employed. Results showed that the average excretion of E.coli O157: H7 in the treatment groups has decreased significantly compared with control groups. It was observed that the average excretion of E.coli O157: H7 in the first day in the group treated with Lactobacillus casei (Lc) has significant difference with all groups except the group treated with Lactobacillus casei and Lactobacillus plantarum (Lcp). Also we found that the average colonization E.coli O157: H7 in treated groups has decreased significantly than control groups. There was also observed that, the highest average colonization E.coli O157: H7 on days 3 and 7 is in the control group (C), but unlike the results it seen on day 3 and 7 that the lowest average E.coli O157: H7 on day 3 is in the group treated with lactobacillus casei (Lc) and on day 7 is in the group treated with of Lactobacillus plantarum and Lactobacillus casei (Lcp). Consumption of milk fermented by L. casei and L. plantarum minimizes the duration of illness and reduces the severity of the illness. Further studies are needed on humans.
The purpose of the present research was to study the organizational citizenship behavior (OCB) of the physical education professors and faculty members of Islamic Azad University (IAU). The research was descriptive-survey. The population of the research consisted of all the physical education professors and faculty members of the Azad universities of Region 8 of Iran during the period 2010-2011. Using purposive and convenience sampling, 45 subjects were selected as sample. The required data was collected through the 24-item Organizational Citizenship Behavior Questionnaire of Podsakoff. Descriptive statistics were used for data analysis. The results showed that the physical education professors and faculty members of Azad universities had an average level of conscientiousness, sportsmanship, civic virtue, altruism, and general OCB, but they were in a good condition in terms of courtesy. Considering the findings of the present research, the university officials must devise proper strategies to improve organizational citizenship behavior among the staff, especially the components of conscientiousness, sportsmanship, civic virtue, and altruism.
Several methods are used to enhance bone repair and new bone formation. Bone matrix gelatin (BMG) is recently introduced. The purpose of this study was to evaluate of allogeneic and xenogeneic effects of bone matrix gelatin on cancellous bone defect healing in rat models. The experiment was conducted on 30 male adult SD rats which were divided into three groups of control and experiments. After induction of general anesthesia, a hole in size of 2×3 mm in diameter and depth was made using a dental bit in the inner aspect of the between condyles of left femur. In control group defect was left untreated. In experiment groups I and II, allogeneic and xenogeneic BMG was used to fill the bone defect. The BMG was prepared as previously described using Urist method. After 45 days all rats were euthanized. The samples were stained by H&E and histopathology and histomorphometry evaluations were performed. In control group, defect seemed to be filled with adipous tissue and in spite of a moderate osteogenic activity and some osteoblasts could already be seen specially was detectable attached to the edge of defects. In experiment groups, many osteoblasts groupings, and young bone trabeculas increased in number and bone trabeculas more organized. Bone trabeculas with regulated osteoblast cells and highly osteogenic activity already are seen. Histomorphometric results, observed that allogeneic and xenogeneic BMG has significant effect on bone healing in experimental groups I and II than control group (p=0.000), but it has no significant effect between experiment groups (p>0/05). This study has shown that exposure to allogeneic and xenogeneic BMG stimulated bone formation in defect area of cancellous bone. The osteoinductive effect of BMG derives from the growth factors within BMG and due to this osteoinductive properties of BMG, provides a more rapid regeneration of bone defects and it is a good choice for the healing of cancellous bone defects.
Preterm birth (PTB) is the leading cause of perinatal morbidity and mortality, but a precise mechanism is still unknown. There are many factors affecting one premature birth. In the past, so many studies developed to explore these factors and their importance, however as mentioned in literature, inter-dependencies between factors, make it difficult to measure the accurate amount of importance. This paper provides the first analysis on the interactive relationships among the factors affecting on PTB in incorporating the disciplinary technique as graph theory named “decision making trial and evaluation laboratory (DEMATEL)” in order to visualize the causal relationships among factors through a cause-effect relationship diagram. The original medical data were collected from a prospective pregnancy cohort by a professional research group in Iran Health Ministry. The results indicate that: twin or multiple pregnancy, vaginal tract infection, maternal chronic stress, low socio-economical status, premature rupture of membrane, intra uterine infection, maternal hypertension and previous preterm birth are the most critical risk factors of preterm birth. Hence, the findings of this study will be useful for parents, medical staff, and public health workers in attempting to consider high risk pregnant.\nKeywords: preterm birth (PTB); critical factors; decision making trial and evaluation laboratory (DEMATEL); graph theory.
Mobile ad hoc networks are characterized by the use of wireless links with limited bandwidth, dynamically varying network topology and multi-hop connectivity. Today, node-disjoint routing becomes inessential technique in communication of packets among various nodes in networks. Meanwhile Ad Hoc On-demand Distance Vector (AODV) creates single-path route between a pair of source and destination nodes. This paper proposes a new approach of multipath node-disjoint routing based on AODV protocol. The extended AODV is called Ad Hoc On-demand Node-disjoint Multipath routing protocol (AONMDV). This research produced simulations of both AODV and AONMDV. The results of comparing the performance of these simulations proved that AONMDV improves performance in compare with AODV.
In this investigation 200 avian pathogenic Escherichia coli (APEC) strains isolated from broiler with Colisepticemia and examined for susceptibility to antimicrobials of veterinary and human significance. Ten different serotypes were identified, with O78 being the most common (19.5%). The majority of the avian E. coli isolates (49%), however, were non-typeable with standard O antisera. In vitro antibiotic activities of 21 serotyping and antibiotic substances against the isolates were determined by disc diffusion test (Kirby Bauer method). The highest rate of resistance was against Nalidixic acid (98%), Lincomycin (97.5%), Erythromycin (97%), Oxytetracycline (92%), Chloretracycline (92%), Flumequine (90%), Doxycycline (80%), Difloxacin (80%), Neomycin (62%), Streptomycin (62%), Trimethoprim-Sulphamethoxazonle (60%), Kanamycin (60%), Enrofloxacin (60%), Norfloxacin (55%), Ciprofloxacin (50%), Chloramphenicol (49%), Furazolidone (45.5%), and Nitrofurantoin (45%). Resistance to Gentamicin, ceftifur and Fosbac were not observed and to Amikacin, Cefazolin, Colistin, Lincospectin and also Florfenicol were low. This study showed resistance rate against the antibiotics that are commonly used in poultry is very high but against them that are only used in human or less frequently used in poultry is significantly low. This study also showed that the prevalence of Quinolone.
When there exists some considerable degree of collinearity among the regressors while dealing\nwith linear regression model, the Liu estimator is one of the commonly used alternative\nestimators to avoid the adverse effects of the conventional least squares estimator in this\nsituation. However, in addition to the problem of multicollinearity, the error terms of the model\nmay also be heteroscedastic at the same time and may lead to some serious issues about the\ninference for the regression coefficients. But in the available literature, the problems of\nmulticollinearity and heteroscedasticity have not been discussed as a combined issue especially,\nfor the inference of the regression coefficients. The present article focuses on the inference\nabout the regression coefficients taking both the issues of multicollinearity and heteroscedasticity\ninto account and suggests the use of some available heteroscedasticity consistent covariance\nestimators for the Liu regression. This article proposes robust t- and F-tests, based on these\nestimators, that perform adequately well in the numerical evaluation of the Monte Carlo\nsimulations.
Abstract\nEconomic growth in is increasingly dependent on the improvement of our educational system. Current initiatives to reform education and improve student performance are based on transforming the province’s schools into professional learning communities (PLCs). A key factor that will determine this reform’s success is the capacity of principals to adopt a collaborative leadership style. This paper examines a study of principal decision-making and the forces both for and against the adoption of the collaborative leadership style required to implement the current school reform. While the majority of principals studied, exhibit the capacity to lead using a collaborative decision-making style, the bureaucratic system in which they work may be preventing them from doing so.\nKeywords: Leadership, School Reform, educational system, decision-making, principal
The main objective of this study was to investigate the effects of terminating irrigation at different developmental stages and Azospirillum inoculation on quantitative and qualitative yield of black cumin (Nigella sativa L.). Treatments consisted of irrigation with three levels (W1 = normal irrigation from emergence to harvest (control), W2 = irrigation terminated at the start of budding and W3 = irrigation terminated at the start of flowering) and Azospirillum inoculation at four levels (A1=non-inoculated, A2=seed inoculated and A3= spraying on the plant base at stem elongation stage, A4= seed inoculated + spraying on the plant base at stem elongation stage). The present results have shown that irrigation terminated at the start of budding caused significant reduction in number of follicles per plant, biomass production and seed yield. But, thymoquinone content increased in response to the water stress. Azospirillum had positive effects in all measured traits, especially when it used at two times (at seed inoculated + spraying on the plant base at stem elongation stage or A4 treatment).
In this paper, the causal relation between stock prices and exchange rates is examined through applying Toda and Yamamoto causality test using weekly data from Brazil, Russia, India, and China (BRIC countries). The sample period started from 5th May, 2003 to 6th September, 2010. The whole sample period was divided into three sub-periods: Pre-crisis, during crisis, and Post-crisis. The series were not found stationary while applied Kwiatkowski, Phillips, Schmidt, and Shin (KPSS) Tests. In the pre-crisis period, Brazil showed bidirectional and Russia and India showed uni-directional relation moving from stock market to exchange market. During crisis period, Russia evidenced the bidirectional causality while Brazil and India showed unidirectional relation running from stock prices to exchange rates. In post crisis period, Brazil and Russia revealed the stability in the relationship during crisis and post-crisis but causality was running from exchange rates to stock prices in pre-crisis period in the case of India. Hence, China is not provided any evidence of relationship between exchange rates and stock prices during all three sub-periods. Overall results of study proved the relationship between the variables in shape of unilateral and bilateral whereas during the entire period of the study, no interaction between variables was highlighted in China.
Reproduction means producing new offspring. Sexual reproduction and asexual reproduction are two modes of reproduction. Reproduction with sex is sexual reproduction. Fission, budding, gemmulation, fragmentation and regeneration are kinds of asexual reproduction.\nReproduction is very important in living organisms and we can not separate it from evolution.
Phylum platyhelminthes contains flat worms.\nClass Turbellaria, class Trematoda, class Cestoda and class Monogenea are the classes of this phylum. Each of these classes has its characteristics that we will investigate them.
Eukaryotic cells and bacterial cells have many structural differences. In this paper we will compare these differences. Two groups of bacteria are: Eubacteria and Archaebacteria. Bacteria are useful or harmful. Harmful bacteria can make human disease of course human can prevent these diseases.many of useful bacteria can be used in industry.
In this paper we will introduce the general specifications of protozoa.\nMost of them are microscopic organisms. Protozoa are unicellular organisms. Most of them reproduce by binary fission. Binary fission is a kind of asexual reproduction.\nCilia, flagella and pseudopodia help many of them to move.
This paper presents the application of Static Synchronous Series Compensator (SSSC) to enhance damping of Low Frequency Oscillations (LFO) at a two-area power system. A supplementary stabilizer based on SSSC is assumed. A combination of Fuzzy method and Partial Swarm Optimization (PSO) is used to design the proposed stabilizer. In this Fuzzy-PSO technique, the upper and lower bounds of the Fuzzy membership functions are obtained using PSO method. This method is so called “scaled-Fuzzy”. The nonlinear time domain simulation results show the ability of the method in damping power system oscillations.
Many traditional treatments have been recommended in the complementary medicine for treatment of Diabetes Mellitus; however, the mechanism of most of the herbals used has not been defined. Allium is a genus of some 500 species belonging to the family Liliaceae. The aim of this study was to determination of the Antioxidative activity of onion alone and in combined use with zinc sulfate. In this experiment, 162 mature male rats (250 gm on the average) were acquired from Razi Serum–producing Institute of Karaj and transferred to keeping place and then divided into the 9 identical groups. It showed that onion alone results in increase in CAT, GPX and SOD content of serum. Also yields to decrease in MDA content. This activity of the onion was potentiated in combined use with zinc sulfate. Onion and zinc sulfate have the most important antioxidant contents that combined use of these elements showed best effect than alone use.
This qualitative and technical study presents that speedy changes in challenge approaches and multi-method human wars have developed tremendous alterations in the area of intelligent power. Determining the dimensions of hybrid intelligent wars to create the frame of intelligent defense resulting from intelligent power to survive and grow and develop systems by protection of intelligent security has a great importance. To extract the final model of upcoming wars or intelligent wars through “Delphi panel”, 30 professors of Payam-e-Nour University were questioned through funnel-shaped method, information gathered and condensed in four stages; and discovered and presented in a model regarding to the components of integrative or hybrid wars. After considering and presenting the four theories of warfare and recognizing the fivefold components of integrative or hybrid wars in a proper frame. The present research method is an applied type with Delphi measurement method, through which the dimensions of types of wars of had, soft, mild and forbidden intelligent wars, respectively:\nHard (warm) wars: by land, marine, air, missile, irregular and urban\nSoft (cold) wars: cultural, social, psychological, through media, political, economic, intelligent, scientific, religious, security \nSemi-Hard (mild) wars: crisis and sedition, rebel and riot, coup and assassination \nAbnormal (forbidden) wars: atomic, microbiologic, chemical and microbus\nThe analytic content of the essay provides a possibility for those who are involved in intelligent security in the area of black operation, irregular wars, mobilization, forces of hard and soft wars as well as other macro-policy makers of system in facing similar situations and intelligent prevention.
This paper reports a novel hybrid method based on optimization techniques and neural networks methods for the stabilization of nonlinear control systems. The requisite control input is generated as the output of a neural network, which is trained off-line such that the time derivative of a positive definite function of the state variables becomes negative at all points. The mixture of feed forward neural networks and optimization techniques, based on Nelder-Mead method is used to introduce the close analytic form of the solution for a energy function. A numerical example shows the effectiveness of the proposed neural network.
This study was aim to determined the levels of some heavy metals in the gills, liver, stomach, kidney, bones and flesh of four fish species (Tilapia zilli, Clarias anguillaris, Synodentis budgetti and Oreochronmis niloticus) collected at River Benue in Vinikilang, Adamawa State, Nigeria for analysis of Cu, Zn, Co, Mn, Fe, Cr, Cd, Ni and Pb. The concentrations of the metals were carried out using Flame Atomic Absorption Spectrophotometer (AAS, Unicam 969). Large differences in trace metal concentrations were observed between different tissues within each fish. The highest concentration of Fe (12.65 µg/g) was recorded in gill of Synodentis budgetti, while the lowest value of 0.68 µg/g was recorded in the flesh of Oreochronmis niloticus The liver of Synodentis budgetti accumulates significant higher levels of Mn and Cd than other species; Fe and Zn was highest in the stomach of Tillapia zilli, while Clarias angullaris shows more of Cr, Pb, Cd and Co. The stomach of Synodentis budgetti accumulate significant higher levels of Fe than other species; Zn was highest in the stomach of Tillapia zilli, while Clarias angullaris shows more of Mn, Cr, Cu, Cd and Pb. Similarly, the bone of Synodentis budgetti accumulates significant higher levels of Mn and Cd than other species; Zn and Fe were highest in the bone of Tillapia zilli, while Clarias angullaris shows more of Cr, Pb, Ni, and Co. The highest levels of Fe (12.65 µg/g) observed in this study was recorded in the gill of Synodentis budgetti and it was below the high residue concentrations of Fe (34-107 ppm) in fish samples. Based on the above results, it can therefore be concluded that metals bioaccumulation in the entire fish species study did not exceeds the permissible limits set for heavy metals by FAO, FEPA and WHO.
This paper presents an optimization method having been utilized to find minimum number of Phasor Measurement Units (PMUs) and locate them in a 57-bus IEEE network in order to maximize redundancy. Considering the cost of installing the PMUs, the minimum number of locations and maximum redundancy should be achieved while the observability is complete over the entire network. Cost function is multi-objective and logarithmic least square method has been used for determining weights of cost function. This method is a part of analytical hierarchy process. In this paper, optimized meta-heuristic Ant Colony Optimization (ACO) is used to solve the PMU placement optimization. Hence, ACO parameters are optimized by Genetic Algorithm (GA). Then, we compare the optimized ACO results with just GA and just Simulated Annealing (SA). The simulation results show the optimized ACO has better results than just GA and just SA.
Gas guns are widely used for launching the projectiles especially for the study of ballistics. The release time of the compressed propellant gas plays an important role in the magnitude of the projectile velocity. It is well known that a faster release can be achieved by using rupture disks. The performance of the rupture disks in turn depends on the disk geometry and material characteristics. In this investigation, three materials including aluminum 6061-T6, steel S304, and steel st37 are examined for the use as rupture disk in a gas gun in which a 100 grams projectile is launched at velocities up to 1500 m/sec. The pressure behind the disks varies from 30 to 450 bars. The investigation is carried out by experiment and numerical simulation for 4-petal disks. The results indicate that (i) the performance of aluminum 6091-T6 and steel st37are quite satisfactory for the test conditions used in this work, (ii) steel s304 is so stiff and ductile at the same time and is not suitable for the test conditions used in this study, (iii) the opening time of rupture disks is proportional to the square roots of material density and ultimate strength and to fracture strain.
