Nowadays, non-destructive tests are becoming more and more popular. Compare to destructive tests, they have the advantage as the measured component is not being destroyed and therefore the production costs and the time required for testing is reduced. One of these non-destructive methods is the measurement with acoustic respond signal known as Barkhausen noise. The principle is simple. The probe which generates a magnetic field moves on the surface of the component and the responses from this probe are shown on the screen of the oscilloscope if the hardness on the entire length of the surface is the same or if the surface contains an error (i.g. a burnout, crack, etc.). The contribution deals with the compartment of values from hardness measurements on the surface of the through hardening bearing steel using Rockwell method whit the acoustic responses from the same surface where hardness was measured. As samples, the cut semicircles from rolling elements (3 pieces) into roller bearings were used. Each element has been heat treated to bainitic structure at different temperatures and for different isothermal hardening endurance.
In this paper, the some characteristic properties of ruled surfaces which are generated by the Darboux frame of the transversal intersection curve of two surfaces were given in 3-dimensional Euclidean space . Also, the relations between the integral invariants of the closed ruled surfaces were showned. Finally, the examples for parametric-parametric and imlicit-implicit surfaces were given.
Abstract\nThe purpose of this study was to assess the vulnerability of Turkey to climate change impacts. The Vulnerability Resilience Index was applied to measure Turkey’s vulnerability. Adaptive/ coping capacity and exposure/sensitivity sectors were taken into account to determine the vulnerability value. Initially, sectors were divided into indicators. Four indicators -economy, human resources, environment, and governance- were selected for the adaptive/coping capacity sector. Six indicators –exposure, settlement, food, ecosystems, health, and water- were selected for the exposure/sensitivity sector. Later, proxies for each indicator were established. Proxy indexes were interpreted to indicators and these indicators were connected to sectors. The overall climate change vulnerability of Turkey was constructed based on sectors’ values. The results of the study showed that economic capacity was the most vulnerable adaptive/coping capacity indicator and ecosystem sensitivity is the most vulnerable sensitivity indicator for Turkey. Current data indicates that Turkey will be fairly affected by climate change.\nKeywords: Climate change, vulnerability, resilience, adaptive capacity, sensitivity, Turkey
This study is to optimize the acetic acid absorption characteristics of carbon fiber epoxy resin composite material by using Taguchi methods. By analysis of variance, it investigates the significant factors affecting the characteristics in this experiment. The experiment reliability is testified by regression analysis. Three kinds of nanopowder, namely, alumina, silica and carbon black, one chemical agent, namely, diluent, are selected as control factor in this study. Orthogonal array L9 is used for this purpose and three control levels for each control factor are established to conduct the acid-resistance test. From the analysis of variance, it was found that alumina, silica, carbon black and diluent are significant factors affecting acetic acid absorption rate of the novel material. A regression model was obtained based on the relationship between the experimental data and the weighted percentage of the control factors. After parameter optimization by Taguchi methods, the acid resistance characteristic of the new rein composite material was up 30.49% than pure resin. The parameter optimization of acetic acid absorption rate obtained from Taguchi methods was substituted into the regression model to calculate the prediction value. This prediction value was compared with the average of experimental values. It resulted into the error 6.5%, which confirmed the reliability of the establishment of the regression model in the experiment.
A dynamic model for an activated sludge process is proposed to investigate the stability and bifurcation characteristics of the industrially important unit. The existence of equilibria is discussed, the stability and the saddle node bifurcation are investigated. New necessary conditions are given for these qualitative properties of solutions. The model also exhibits other interesting stability characteristics, including bistability and transition from periodic to nonperiodic behavior through period doubling and torus bifurcations. Numerical example is computed to ensure our analytical results.
The problem of optimizing the fuel consumption needed for orbital maneuvers is investigated. The normal to the orbit components of the atmospheric drag and lift forces , as well as the normal component due to direct solar radiation pressure (DSRP) are obtained. The temporal variations in the inclination using Lagrange planetary equation are derived, then are integrated over one revolution. The velocity variations required to perform the propulsive maneuvers due to engines on board the satellite are calculated.
There have been a number of changes pertaining to language teaching since the end of apartheid education in South Africa. During the apartheid years there were only two recognised official languages, English and Afrikaans as policy overlooked indigenous languages. Currently though, there are eleven recognised official languages as well as the sign language. Furthermore, the existing Language-in-Education Policy seeks to ensure that all these official languages are promoted and developed as programmes are developed to redress the previously disadvantaged languages. \nThis article explores a qualitative study done at four daycare centres where 30 parents were part of a sample. The researcher wanted to understand how parents view the use of black African indigenous languages. Interviews and observations were conducted over a given period. The paradox in the results shows that although the parents exercise the choice of language which includes choosing the previously marginalised black indigenous languages, many prefer English for their children. The participants perceived the English language as a language that would give their children better chances in society. The findings also reflect how language choice can widen the achievement gap between the historically advantaged and previously marginalised schools.
The article investigates the interrelation between culture and phraseological units including proper names on the base of the English, Russian and Kazakh languages. The topicality of the research article is determined by: 1) continued interest in learning various relations of language, thinking and culture as well as representation mechanisms of stereotypes in language; 2) integration tendencies of research paradigms in linguistics, in particular systematic and functional approaches; 3) constant tendency to order the system of expressive means in language; 4) trinity of the Kazakh, Russian and English languages and their co-existence on the territory of the Republic of Kazakhstan; 5) multilingualism and its effect on people’s linguistic worldview. The article states several definitions of the term “stereotype” in modern linguistics thus emphasizing its significance and multiversity. To indicate the reflection of history and culture in language the etymology of a number of set phrases is given as well. Methodological base of the research paper is formed by the system of fundamental representations of general interrelation of language and thinking, language and person, language and culture and their interdependence. The basic methods of the research paper are methods of linguistic observation and description which intend to interpret peculiarities of the investigated language units, an explanatory method and component-semantic analysis. It should be noted that the analysis has been conducted in an integrated way by using the methods appropriate to the given aim and tasks on each stage of the work. General scientific base of the paper is formed by principles of anthropocentrism, systematization and determinism.
The energy distribution for the photo- production of leptonic - pairs in the electric (coulomb) field of the nuclei and at different energies of the incident photons (from up to ), can be studied in details.\nObtaining a general formula for the energy cross-section of the pair-production processes due to the interaction between the electromagnetic photon field and the coulomb field of the light nuclei. Applying the obtained formula to the and - stable nuclei for the three cases of the produced pairs.\nThe circular polarization of the incident photon, and the longitudinal polarization of the particles of pair can be taken into consideration. The energy of the incident photons are selected in different ranges (from up to ), obtaining numerical values for the energy cross -sections of the processes for the three types of Lepton-pairs, and using different diagrams to compare the pair - production process at every range of energies to obtain the best results for the energy values of the incident photons to produce the pairs.
The living organisms use defensive mechanisms in their struggle to keep the inner homeostasis and potect themselves from the changes induced by external factors and penetrative agents. The manifestation of these changes depends on the character, the intensity and the duration of the agents’ activity, and on the physiological characteristics of the organism (gender, age, health condition etc.). \nThe aim of our study was to analyze, the effects of collagen-induced arthritis (that is, the autoimmune reaction and the inflammation) on some liver parameters. We determined the content of proteins, DNA and RNA. Animals with collagen-induced arthritis showed decreased relative content of proteins in liver, compared to controls. On the contrary, the relative content of DNA and RNA were increased in animals treated with collagen.
An experimental study of the thermal performance characteristics of TMA glass transition temperature is developed. Three kinds of nanopowder material, namely, alumina, silica and carbon black, are selected and mixed with diluent to prepare a new glass fiber epoxy composite. By analysis of variance, it is found that the control factors, named as alumina, silica, carbon black and diluent, are significant factors to qualify the characteristics of the glass transition temperature of the novel composite material. In the study, the glass transition temperature is effectively optimized by using Taguchi method. The regression equation can be established from the experiment to determine the weighted coefficient of control factors and quality characteristics. The error between the experimental value and the prediction value, which is calculated by the regression equation, is only 2.88%. It confirms the reliability of this study.
In an effort to enhance the reliability of threaded fasteners, the wear and anti-loosening characteristics of a flank lock type precision locknut considering dynamic conditions was performed. The empirical study was realized by using horizontal realistic dynamic percussion vibration test machine. The machine can simulate the loosening condition of the locknut which was assembled in ball screw and machine tool spindle. The specimen is a flank lock type locknut which is made of chrome molybdenum alloy steel SCM 440. Through this study, the wear resistance and anti-loosening characteristics of the locknut under the dynamic test were investigated by closely observing the roughness, flatness and tooth angle, seat surface and surface morphology before and after the test. The test results were used to calculate axial force ratio and anti-loosening ratio to understand the wear properties and anti-loosening properties of the type of precision locknuts under dynamic conditions. From the experimental results, it was found that a significant wear was generated on the surface of the locknut after the dynamic test. The study observed the axial force and the anti-loosening ratio and found that there existed a tendency between them. It is concluded that the higher the anti-loosening ratio is, the less the axial force decline.
Abstract \nThe aim of the study was to apply the instrument EAPH-MF to students in an institution of higher education in \"Tierra Blanca Veracruz, Mexico\", in order to see if these results are similar to the original research, entitled \"A teaching model based on the design of simulators: the case of financial mathematics, \"Garcia-Santillán, Escalera and Edel (2011). For this empirical studies were applied 209 instruments to Industrial Engineering students who are registered and have completed at least one financial mathematics course. The obtained results allow us to confirm that both populations have similar behaviors when in the process of teaching-learning, using didactic strategies involving the variables EAPH_MF scale, same which as a whole account for 60% of the variance of the studied phenomenon.\n\nKeywords: Contrasting, Financial Mathematics, equivalent behaviors, attitudes of students
Atrazine is one of the most environmentally prevalent s-triazine groups of herbicides that inhibit photosynthesis of broadleaf and grassy weeds. Degradation time of this compound is about 200 days and is frequently found as contaminant in ground water. In the present study, atrazine degrading bacterium (strain ATT) was isolated from agricultural drainage ditches (Fayoum, Egypt) by enrichment technique. Based on morphological, biochemical and 16S rDNA gene sequencing, this bacterium was identified as Ochrobactrum oryzae. A pure culture of O. oryzae were grown in minimum media supplemented with atrazine as sole carbon and nitrogen source. The influence of atrazine concentration as well as temperature and pH on the bacterial growth and rate of atrazine degradation was investigated. The maximum capability of atrazine degradation (83.5%) was achieved at concentration 400 ppm of atrazine within 9 days at pH value 9.0 and temperature 30°C. Therefore, O. oryzae can be used efficiently for the environmental cleanup of agricultural wastewater contaminated with high levels of atrazine.
A new mathematical model for the gas and solid phases Catalyzed polybutene fluidized bed reactor using metal oxide catalyst is presented in this study. This mathematical model, accounts for mass and heat transfer between bubble and cloud phases without chemical reaction and between cloud and emulsion phases without chemical reaction and between emulsion and solid phases with chemical reaction that occurs at the surface of the catalyst particles. The proposed mathematical model evaluates the effect of catalyst flow rate and superficial gas velocity on the system. Concentration and temperature profile changes are also estimated. Moreover the results of the proposed model are compared with experimental data in terms of concentration and temperature reaction. Obtained results show good agreement between proposed mathematical model and the actual plant data.
Endophytic bacteria may be considered as a rich source of useful metabolites with potential application in the biological control of phytopathogens. A total of fifty two endophytic bacteria were isolated from different crop plants collected from Fayoum Government, Egypt. These isolates were in vitro screened for the antimicrobial activity against some fungal and bacterial phytopathogens. The isolate H8 showed a strong antifungal activity against Rhizoctonia solani & Pythium ultimum while strain H18 demonstrated high antagonestic activity against Erwinia carotovora & Rhizoctonia solani. At the same time, the maximum inhibitory rate of the isolate H40 was recorded against Erwinia carotovora & Fusarium solani. The bacterial isolates were characterized and identified using 16S ribosomal DNA technique as Stenotrophomonas maltophilia, Bacillus subtilis and Pseudomonas aeruginosa. This study suggested that the bacterial strains S. maltophilia (H8), B. subtilis (H18) and P. aeruginosa (H40) are valuable biological resources that might be used as potential antimicrobial agents against plant pathogens.
This study was conducted to monitor methomyl, oxamyl and carbosulfan carbamate pesticides residues in tomato fruits grown in Jordan Valley during the period from January to May in 2012 using a modified gas chromatographic method equipped with nitrogen–phosphorus detector (GC-NPD). Sixty samples of tomato fruits collected randomly from different farms in Jordan Valley were extracted and analyzed for studied carbamate residues. Methomyl was found to be the most abundant carbamate pesticide. Methomyl residues were found in 90% of the collected tomato fruits samples and 70% of these samples contained methomyl residues less than the maximum residue limits (MRL). Oxamyl residues were found in about 20% of the collected tomato fruit samples, however oxamyl residues were found to be less than the maximum residue. Carbosulfan residues were not found in any of the collected and studied tomato fruit samples.
Objective\nThe objective of this study is to characterize mycetoma by ultrasound and to describe the incidence mycetoma.\nMaterial and methods\nThis study carried out in soba university hospital in Khartoum state in the period from 18 March-13 November 2012 using equipped by high quality ultrasound machine type Aloka SSD 3500 with high frequency transducer 7.5 MHz. A total of 100 patients Their ages between (10-50) years , suffer from the foot mycetoma. and most of them were undergone routine plain x-ray were recruited for this study \nResults\nThe main findings of this study show the foot mycetoma more common in males (76%) , Most common affected age intervals(21-30) years, 32 case, and (31-40) years (32%), the most common area from Aljazeera state (57%) and the fungal type (78%) than bacterial type (22%).. The study revealed that the major of pt workers 61(61%) , the type of Mycetoma, 22 (22%) actinomycetoma and 78(78%) were Euomycetoma, Ultrasound appearance of Mycetoma with Grain 51(51%) and the type of fluid collection was found than 48 with fluid collection, it was found that 67(67%) with intact, and verified that the ultrasound examination of foot mycetoma is simple, reproducible, and low cost . \nConclusion\nThe study concluded that ultrasound and Doppler has high efficiency in diagnosis of mycetoma and very accurate in diagnosis of mycetoma and even in differential diagnosis of its types. it must be used as first diagnostic tool.
The information security is getting bigger issues now days that most of the organizations are concerned how to control and prevent the confidential information leakage from the organization to the outsider. IEC/ISO27001 Information Security Management System (ISMS) is to provide a standard framework, governance and guidance on managing information security within an organization. This research study focus on the significant feasibility study on how the organization can adopt the ISO27001 ISMS standard framework in order to apply the benefits of the security controls and best practices to mitigate the complexity of infrastructure of organization information leakage and improve confidentiality, integrity and availability of information security within an organization.
Introduction : Ochratoxin A (OTA) is a mycotoxin produced by Aspergillus Ochraceus as well as other moulds and it is known to cause hepatotoxicity and nephrotoxicity in animals and humans . The effect of Ochratoxin A (OTA) on the histological structure of liver and kidney and the possible ameliorating effects of Nigella sativa oil were investigated in the present study.\nMaterial and Methods: Twenty-four male albino rats were used in the present work and divided into three groups(eight rats each) :control; OTA-treated and OTA plus Nigella sativa oil (NSO)treated groups . The rats in the control group were administered only a daily oral administration of sodium bicarbonate. OTA was administered orally with a single daily dose of 289 ug/kg per day. OTA and Nigella sativa oil were administered orally with OTA (289 ug/kg per day ) and Nigella sativa (0.3 ml /day) in two different periods of time during the same day.\n Results: The histological changes in the liver and kidney tissues of control, OTA and OTA+ Nigella sativa oil-treated rats were examined. Significant histological changes were found in the kidney and liver tissues of rats treated with OTA. These were vacuolar degeneration and necrosis of the liver cells, sinusoidal and central vein dilation, bile duct proliferation , dilation and congestion of portal vein as well as cellular infiltration and mild increase in the amount of collagen fibers. Also decrease in the amount of protein and carbohydrates were observed. In the kidney, tubular epithelial cells degeneration, necrosis in the nuclei , decrease in the amount of protein and carbohydrates and `fibrous tissue proliferation. The severity of the lesions was significantly reduced by administration of Nigella sativa oil. \nConclusion: These results revealed that OTA induced significant histological changes in liver and kidney tissue advocating OTA toxicity and administration of Nigella sativa oil plus OTA significantly reduced the toxic effect of OTA on kidney and liver tissue of rats .
In this paper the issue of democracy, demography and economic growth has been investigated. As the results prove the effect of democracy on economic growth are positive and statistically significant in all of the models presented in the paper. While the coefficient on the logarithm of population is ambiguous, whether one checks for the sign on that variable or its statistical significance. This is in line with the population neutralism view. Besides, the main variables models are augmented with other explanatory variables, and dependent side variable in some regressions is economic development. In the last section of the empirics of the paper there are presented two models, where this study controls for age structure of the population.
Abstract\n\nThe purpose of the article is to show a new solution to the problem of the multiculturalism policies minority populations face in modern western countries. The method it uses is philosophical comparativistics and phenomenology. According to the results of the investigation, the most efficient way to handle the issue of the multiculturalism policies minority populations face in modern western countries could be spreading amidst the minority populations of the values of altruistic service to others without anticipation for any reward whatsoever. In the case of Islam, these values can be shown on the basis of Islam’s authentic sources to constitute the most essential part of Islamic philosophy of life.
The article aims to test the organizational citizenship behavior (OCB) model which was introduced by Organ et al. in 1990 in the Iranian healthcare industry. The authors take a quantitative approach based on a survey involving 152 questionnaires. The respondents were employees of six hospitals in Tehran, Iran. Correlation tests and standard, stepwise regression analyses were conducted to test the hypothesis and research questions. Organizational citizenship behavior is a component of job performance and vital for the development of an industry. It is a function of five dimensions: altruism, conscientiousness, sportsmanship, courtesy and civic virtue. The findings show that all dimensions have a positive relationship with OCB; civic virtue is the most salient dimension, with a 0.405 coefficient beta. The findings also support that OCB is positively related to job satisfaction, with a 0.183 coefficient beta. The paper is useful to organizational-behavior practitioners and academics. It provides some initial insights for managers in the Iranian healthcare industry by encouraging employees’ engagement in OCB, which will increase employees’ job satisfaction and organizational aspects. For the academics, the model is proven that it can be implemented in healthcare industry in Iran, and hopefully it can also be implemented in other industries.
Nowadays, there has been more and more attention paid to renewable energy sources [1] as well as to more efficient use of energy. The article consists of two parts. It is devoted to the cogeneration system with the Stirling engine. In the first part of this work there has been the thermodynamic analysis for the Stirling cycle shown. It has been performed for nitrogen and helium – the most frequently applied working gases in the Stirling engines. Information gained on this basis is related to theoretical possibility to increase the Stirling cycle efficiency. In the second part of this article there are the results of experimental research presented, performed on the cogeneration system with the single – action Stirling engine, alpha type. The results have shown the influence of the upper heat source temperature (Th), working gas pressure and type of the working fluid (nitrogen, helium), on the Stirling engine performance, including electric power cogeneration values. As a heat source for the cogeneration system the LPG gas combustion was used.
The main objective of this study is to measure aortic diameter and to estimate the cardiothoracic ratio. The study was carried out in the College of Radiologic Technology, The National Ribat University,Khartoum Sudan , Special Diagnostic Centres, Khartoum Sudan. PA chest radiographs of 50 individuals of age 19 - 70 years were used for this study included both genders.The research presented a mean value of 53+6 millimeter (mm)for the aortic arch diameter of the Sudanese population. Mean aortic arch diameters have been established. The research also set lower and upper limits of normal aortic arch diameter for the two sex groups. Relationship between aortic arch and heart diameter was established and aortic arch diameter was noted to be significant in evaluating aortic and cardiac enlargements. The research noted higher values of aortic arch diameter in males than in females . Age and heart diameter showed strong, positive statistically significant relationships with aortic diameter. Keywords: Aortic diameter, cardiothoracic ratio, adults, Sudanese
Motivation played an important role in achieving mastery of the foreign language. The factors surrounding students also involve in affecting students’ motivation. This study attempts to investigate the level of motivation among excellent students from national secondary religious schools in Malaysia, and factors surrounding them that affected their motivation. The participants were from a pool of 520 top form four students from 26 national secondary religious schools in Malaysia. The questionnaire was designed to investigate the level of students’ motivation in learning Arabic language and also to determine the factors surrounding them affected their motivation. The result showed that the above students have high level of motivation and the factors - academic purpose, religious, family, Arabic country and Arabic activity – played important role in enhancing their motivation.
Control technology is using the computer, especially remote one of the most important indicators of the development of the countries in the field of engineering application, especially if mixed with industrial implementation. This paper presents the design and implementation of an integrated industrial application to use with new reconstruction of a robotic arm (PUMA 560) on this implementation controlled by computer through PIC microcontroller.\nSpecial form of robot PUMA 560 is constructing with three joints two of them are moving joints and third constant at angle 90 degrees and three links Griper, the movement of each joint is controlled through the control of the DC Motor using PIC Microcontroller. \nThe design and implementation of electronic circuits for drive the motors these are used with the robot and working platform and Interface with the computer to control it on the orders of the computer. This design has been implemented in two phase’s simulation by software and then practical implement, satisfactory results are obtained which ensure the ability to dependent this design with many industrial application.
Residual stresses of pure titanium and anodizing titanium interlayer were measured using x-ray diffraction (XRD) method. The X-ray diffraction technique was used to provide residual stress measurements of pure titanium and anodized titanium. \n XRD analysis also showed the presence of tensile stress in the titanium substrate while presence of compressive stress in the TiO2 nanotubes interlayer . The measured residual stresses in the TiO2interlayer are -6.15 MPa and -8.8 MPa for anodized 10 V and 30 V respectively.
This paper presents the idea and development of a mathematical model as the basis for creation of the heuristic algorithm for detection of pathological murmurs characteristic of mitral valve prolapse - MVP.\nThe research is based on the numerical processing of phonocardiographic - PCG signals obtained by the electronic stethoscope auscultation that enhances tones and murmurs of a heart, muffles sounds of surrounding tissue and background noise allowing better interpretation of auscultatory finding than a conventional stethoscope.\nThe electronic stethoscope records, memorizes and sends digitally processed sound recording into the computer in which phonocardiographic recording can be further analyzed.\nCharacteristic phonocardiographic recording for mitral valve prolapse is a click that occurs during systole, after the first heart tone, usually in the middle of systole, as a sudden and short jump of amplitude, which can be followed by high frequency vibrations of a crescendo type and which ends before aorta component of the second tone.\nDigitalized phonocardiographic recording has been processed by elementary statistics and studied as such in a mathematical model based on the mean of integrals in the functional analysis.\nThe authors hope that they have contributed to non-invasive, simple, easily applicable and inexpensive diagnostic method of MVP with this study.
Mathematical modeling processes may not reflect the true behavior of the system for the uncertainties that may affect the system model. In this work, the problem of diagnosis of uncertain nonlinear systems is tackled. Were procured in a state estimation considering uncertainty in the model parameters (state matrix, control matrix and observation matrix). An innovative method is developed to solve this problem. The method is to use bounded approach for estimating state vectors that are uncertain at the base. This approach assumes that uncertainty is random and with unknown probability distribution, except the upper and lower bounds of uncertainties are known. Each parameter is considered as an interval with known bounds. Nonlinear models are represented as multiple model form. An estimated interval of each sub-model will be calculated to derive the estimated overall system suite. If the system is safe, the estimated measures, will be in the form of an interval includes the real outputs. Otherwise, it indicates a faulty functioning system.
For many decades now, people with Down syndrome have been regarded as a problem for society, masking a vision marked by irrationality and rejection to disability (Cáceres, 2004). Teachers have become a powerful tool that is capable of moulding and provoking changes in that perception. For this reason, it is extremely useful and important to know beforehand the perception of teachers in general, and Physical Education teachers in particular, with respect to people with Down syndrome, due to their proximity and professional closeness to this group of people. A longitudinal study has been conducted covering the last decade of the present century for the purpose of ascertaining the perceptions of Physical Education teachers about people with Down syndrome and how they have evolved during this decade. Using a quantitative design, the instrument used was the Down Syndrome Social Perception Scale, followed by a detailed factor analysis based on the perception regarding inclusion, protectionism and acceptance of people with Down syndrome. The analysis revealed the trends experienced during the study period and the main conclusions with respect to the preoccupying situation that exists at present, in view of the increase in the perception of rejection to people with Down syndrome.
In the present study; algae of four freshwater lentic ecosystems including Mogan (Ankara), Karagöl (Ankara), Abant (Bolu) and Poyrazlar (Sakarya) Lakes (Turkey) were investigated. Samples were collected between the dates of October – November 2012 and in March – April 2013. Some physical and chemical water quality parameters (temperature, pH, dissolved oxygen, electricity conductivity, secchi disc and ammonia) were measured during the field and laboratory studies in order to determine the water qualities of lakes. Cluster Analysis was applied to all detected physical, chemical and biological data in order to classify the lakes in term of different characteristics and same biotic indices were applied to the results in order to determine the pollution levels of lakes. According to abiotic data, Mogan, Karagöl, Abant and Poyrazlar Lakes have I. –II. Class water quality in terms of almost all investigated limnologic parameters. According to biotic data, a total of 103 Bacillariophyta species, 47 Chlorophyta species, 20 Streptophyta species, 36 Cyanobacteria species, 6 Dinoflagellata species, 8 Euglenophyta species and 4 Crytophyta species were identified from planktonic samples of four investigated freshwater lakes. According to results of Algal Species Pollution Index, the nutrient levels of investigated lakes were determined as Mogan Lake > Poyrazlar Lake > Abant Lake > Karagöl Lake in terms of identified algal species and Mogan Lake > Karagöl Lake > Abant Lake > Poyrazlar Lake in terms of identified algal genera respectively. According to results of Cluster Analysis, the order of similarity coefficients belonging four investigated lentic aquatic habitats were determined as psychochemical status (0.77) > Bacillariophyta (0.52) > Chlorophyta (0.47) Cyanobacteria (0.44) > respectively.
In this paper a comparison of classical metaheuristic techniques over different sizes of petrochemical blending problems is presented. Three problems are taken from the literature and used for initial comparisons and parameter setting. A fourth instance of real life size is then introduced and the best performing algorithm of each type is then applied to it. Random search techniques, such as blind random search and local random search, deliver fair results for the smaller instances. Within the class of genetic algorithms the best results for all three problems were obtained using ranked fitness assignment with tournament selection. Good results are also obtained by means of continuous tabu search approaches. A simulated annealing approach also yielded fair results. Comparisons of the results for the different approaches shows that the tabu search technique delivers the best results with respect to solution quality and execution time for all three the smaller problems under consideration. However, simulated annealing delivers the best result with respect to solution quality and execution time for the introduced real life size problem.
