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Showing 70 results for Effects
Volume 0, Issue 0 (8-2024)
Abstract
Aluminum nano-films are one of the functional elements that have various applications in different fields such as strengthening cement base materials, improving the performance and efficiency of concrete, and enhancing the mechanical and volumetric properties of clay. In this study, the mechanical responses of aluminum nano-film are investigated under uniaxial tensile and compressive tests using the molecular dynamics (MD) method. The initial configuration of the nano-film is constructed based on a 3D aluminum core—alumina shell model that provides a suitable description of surface oxidation in the nano-film. This model is useful to determine the influence of surface oxidation on the mechanical behavior of nan-film. Because of the accuracy and competency, the inter-atomic interactions are evaluated using the EAM+CTI potential, which is a hybrid potential consisting of two components, i.e., EAM and CTI potential, such that it can also take into account the electrostatic interactions between the atoms. After establishing the initial configuration, the energy minimization process is performed on the nano-film, and then its temperature and pressure are adapted to the environmental conditions through the relaxation process. The MD analysis is accomplished by the open-source LAMMPS software, and the visualization of outputs is performed by the open-source OVITO software. The periodic boundary condition is imposed on the lateral sides of the nano-film to eliminate the free surface effect of the atomistic analysis. The tensile and compressive tests are applied to the nano-film in accordance with the experimental tests, and the stress—strain curves are determined. The concept of Virial stress is employed to calculate the stress of the atomic model, which is equivalent to the conventional Cauchy stress in classical mechanics. In order to diminish the dynamic effects, deformation is incrementally applied to the nano-film, such that at each increment, a small strain is gently imposed, then the nano-film is relaxed under the deformed conditions, and finally the stress and strains are evaluated. The numerical simulations are verified by comparing them with experimental data, which demonstrates the acceptable accuracy of the obtained numerical results. The influence of various parameters such as the thickness and the percentages of oxide layers are investigated on the mechanical response and stress-strain curve of aluminum nano-film under the uniaxial tests. It is demonstrated that the thickness of the oxide layer significantly impacts the mechanical behavior, such that the hardness and energy absorption capacity of the nano-film is increased considerably by increasing the percentage of the oxide layer thickness. However, increasing the total thickness of the nano-film leads to a decrease in the Young’s modulus and elastic limit of the specimen. It is because of the decrease in the percentage of oxide layer thickness by increasing the total thickness of the nano-film. Point defects are one of the important imperfections in the crystal structures of atomic configuration that have a significant effect on the mechanical behavior of materials. In order to investigate the influence of point defects, different percentages of voids are generated by randomly omitting some atoms in the nano-film domain. The generated specimens are analyzed under the uniaxial tests, and their mechanical characteristics are evaluated. The numerical simulations demonstrate that the hardness of the nano-film is significantly reduced by increasing the point defects.
Volume 1, Issue 1 (3-2023)
Abstract
Nowadays, application of enhanced oil recovery methods has increased; therefore it’s necessary to determine their impacts on environment and human life. So, this research investigates the environmental impacts of conventional enhanced oil recovery methods and new methods such as using electromagnetic waves, ultrasound waves, and nanoparticles. The investigations show that electromagnetic waves and ultrasound can effectively remove many environmental pollutants. Characteristics of the wave and the type of formation determine that these waves have different effects on the formation, and efforts should be made to understand these effects to prevent damage to the formation. Nanoparticles can also reduce the quantity of pollutants in the environment. According to the mechanisms of entrapment of nanoparticles in the porous medium, they may remain in the reservoir and find their way to the underground water over time, so their environmental effects should be considered in the long term. A better knowledge of new methods of increasing oil extraction will lead to the identification and use of more suitable methods with less environmental effects (compared to conventional methods).
Volume 1, Issue 2 (7-2013)
Abstract
Abstract:
Relying on the dramatic effects and all cultural potentials of Iranian old and poular literature, this paper aims to deal with the possibilities to contemporarize them for new media productions. Literature is one of the most prominent icons of Iranian rich culture. A notable part of Iranian literature is composed of folklores and popular narratives, which are genuinely full of novel themes and authenticated knowledge to be adapted into film and TV series. The present research will show why exactly Iranian contemporary film-makers and play writers, despite the existing large culrual legacy, have failed so far to apply the potential capabilities. Using a pathological approach to the historical discontinuities happened during the evolution of dramatic functions of Persian old narratives, this study attempts to present a qualitative assessment of these literary art works. After reconsidering the most significant elements of Iranian popular narratives, the paper goes then to propund some common ignored challenges concerning the "adaptation" techniques for media productions. Finally, we would describe a typical narrative of Iranian folklore by which a practical method for new possible adaptation for Iranian TV drama might be provided.
Volume 2, Issue 2 (9-2018)
Abstract
In this study, the effects of drying temperature and mechanical pressure on the surface structure and dynamical properties of polyaniline (PAni) were studied. PAni was synthesized through the aniline polymerization process in the presence of ammonium persulfate in acidic medium and normal methyl-2-pyrrolidine solution. The obtained solution was dipped on a substrate of quartz glass. Atomic force microscopy (AFM) analysis based on nano-indentation tests were used to determine the values of hardness, Young’s modulus and Poisson’s ratio of the films. The results of the analysis of the scanning electron microscope demonstrated that the surface morphology of the film is changed from a fiber-to-interconnected cross-linked networkby increasing the drying temperature. The transmission electron microscope analysis showed that the diameter of the fibers on the surfaces dried at 318 K and 418 K was 18 and 30 nm, respectively. AFM results showed that the mean surface roughness of PAni film at 318 K without mechanical pressure was 63 nm, while for the film pressed at 5 MPa was less than 35 nm. Thermo-mechanical analysis showed that the glass transition temperature of the PAni film prepared without mechanical pressure and the film pressed at 5 MPa were 386 K and 378 K, respectively. Investigating the temperature dependence and applied pressure on the film surface in determining the viscoelastic properties of the PAni nanostructured film can provide readers with appropriate information about the storage and loss modulus of the film and the activation energy of the polymer layer during the thermal decomposition process.
Volume 2, Issue 4 (3-2014)
Abstract
Identification of intertidal echinoderms and the effect of environmental factors on their density and distribution in five stations around the Khark Island were seasonally investigated. Three transects were designated to cover the supralittoral, eulittoral and sublittoral zones within each station. The environmental factors such as temperature, salinity and total organic maters (TOM) were also recorded. Maximum and minimum water temperature were recorded in summer (35.94 ± 0.28) and in winter (18.34 ± 0.39) and the maximum and minimum salinity were recorded in winter (44.6± 0.14) and spring (37 ± 0.18), respectively. Maximum and minimum percentages of total organic maters (TOM) were observed in summer (9.63 ± 0.71) and winter (3.39±0.15), respectively.Totally four species belonging to for families were identified, viz. Asterina burtoni, Echinometra mathaei, Holothuria atra, Ophiothrix sarignyi, the highest frequency of which was encountered by E. mathaei. The maximum density and distribution were found in spring and minimum in summer and winter.
Volume 2, Issue 4 (12-2013)
Abstract
Cotton bollworm, Helicoverpa armigera (Hübner) is one of the most destructive insect pests on many crops in the world that has been found to develop resistance against conventional insecticides. Using insecticides with different modes of action may result in appropriate control of the pest and delay insecticide resistance development. In this study, lethal and sublethal effects of emamectin benzoate and cypermethrin insecticides were investigated on third instar larvae of H. armigera by residue contact methods at 26 ± 1 oC, 70 ± 5% RH and a photoperiod of 16:8h (L: D) under laboratory conditions. LC50 values, on larval stage of the pest, of emamectin benzoate and cypermethrin were 1.75 and 127.74 µg a.i./ml, respectively. According to the findings, the larvae that were exposed to the LC30 of emamectin benzoate and cypermethrin exhibited lower pupal weight and increased larval and pupal developmental times compared with control. The longevity and fecundity of adults were significantly affected by the insecticides. Emamectin benzoate and cypermethrin reduced fecundity by 53.1% and 50.5%, respectively compared to control. The LC30 values of emamectin benzoate and cypermethrin reduced egg hatching by 62.06% and 37.9%, respectively. It is predicted that these insecticides, especially emamectin benzoate, may induce significant effects on population of H. armigera.
Volume 3, Issue 3 (12-2013)
Abstract
Abstract The present study aimed to investigate the relationship between developmental performance appraisal and Job performance mediated by organizational commitment and organizational support in the employees. This study performed in the Gas Company of Guilan Province in 2013. A number of 217 employees were selected as the participants using classified random sampling consistent with the sample size. Participants in this research complemented following Questionnaires: developmental performance appraisal, Organizational Commitment, Organizational support, Task Performance and Organizational Citizenship Behavior. To confirm the scale factor structure and to evaluate the suggested model, confirmative factor analysis and structural equation modeling were conducted. Moreover, Bootstrap Test was adopted to examine its mediation and meaningfulness effects. The results revealed that the suggested model satisfies a good fitting regarding provided data. The research findings showed that only the indirect path of developmental performance appraisal, organizational commitment and organizational citizenship behavior was meaningful, while the other three indirect paths (developmental performance appraisal, organizational support and commitment on task performance and developmental performance appraisal, organizational support and organizational citizenship
Volume 4, Issue 2 (7-2013)
Abstract
The message recall effects consist of the primary effects, middle effects and recency effects. People who recall the first part of the list are affected by the primary effects, those who recall the middle part are affected by the middle effects, and those who recall the last part are affected by the recency effects. The present research is to investigate the recency effects of Persian verbal radio commercials on the memory of their listeners. Also the study is to represent the effects of using short sentences and slogans in Persian radio commercials. The research methods are the field study and experimental. To perform the trials, six out of the 50 Persian radio commercials were chosen, which were broadcasted from Iran, Javan and Payam radio channels in February and March, 2011. Six blank-sentence tests were designed according to the commercials. 71 participants (44 men and 27 women) were randomly selected. Listening the commercials twice, they wrote the missing words in the tests they recalled. The results suggest the recency items with minrank (2/77) of a Persian radio commercial have more effects on the listeners’ working memory and are recalled better than the primary (2/16) and the middle items (%1/06). Also short sentences and slogans (99/79) have more effects on the listeners’ working memory and they are recalled well than the others (41/80). The results are suitable for Persian radio commercial programmers, goods producers and service institution administrators to take the listeners’ attractions to introduce their goods and services better. Linguists and psychologists can also use these results to study the effects of sentence positions on people's memories.
Volume 5, Issue 1 (3-2016)
Abstract
The effect of two insecticides, imidacloprid and pyriproxyfen, were investigated on some biological parameters of ladybird beetle Menochilus sexmaculatus (F.) (Coleoptera: Coccinellidae) under laboratory condition. Theladybird beetle were exposed to insecticides by ingestion of the common pistachio psylla, Agonoscena pistaciae Burckhardt and Lauterer (Hemiptera: Psyllidae) (prey). For imidacloprid, maximum field recommended concentration (MFRC) (1/1 MFRC = 140 ppm), 1/2 and 1/4 MFRC were tested. For pyriproxyfen dilutions of 1/1 MFRC (50 ppm), 2/1 and 1/2 MFRC were used after 24 h. The 100% mortality was observed with imidacloprid in all tested concentrations, whereas no mortality was observed by pyriproxyfen even at the highest concentration (2/1 MFRC). Because of the high mortality observed with imidacloprid, lower concentrations of 1/10, 1/20 and 1/40 MFRC were tested and all predators were killed 3, 7 and 10 days after treatment, respectively. At 1/100 MFRC, no eggs were laid but prey consumption was continued for two weeks. At 1/1 and 2/1 MFRC of pyriproxyfen, ingestion of prey was reduced by 18% and 23%, respectively. At 1/1 and 1/2 MFRC of pyriproxyfen, fecundity and fertility of the coccinellid predator was decreased to 43% and 24.5%, respectively. Imidacloprid at 1/100 MFRC caused significant reduction on fecundity but had no detrimental effect on fertility of the produced eggs. Therefore, unlike the pyriproxyfen that had not acute toxicity, the imidacloprid was extremely toxic to coccinellid at MFRC. However, pyriproxyfen was able to affect on feeding ratio and reproduction of M. sexmaculatus.
Volume 5, Issue 2 (6-2016)
Abstract
Glyphodes pyloalis Walker is a serious pest of mulberry trees in Iran. In this study, lethal (LC50 = 19 ppm) and sublethal effects (LC10 = 3.74 andLC30 = 9.77 ppm) of lufenuron were evaluated against 4th instar larvae of G. pyloalis. After treating the larvae at LC30 and LC50 level, most of them died during the molting process and only a few individuals developed to the 5th larval instar. The highest rate of mortality wasobserved in 5th larval (68.42%) and pre-pupal (59.57%) stages at LC50 concentration. Also, lufenuron caused an increase in larval, pre-pupal and pupal developmental periods. The successful pupation decreased to 53.64% at the LC30. Also, no prepupa molted to pupation after treatment of larvae at the LC50. Larval weight was significantly reduced at 48, 72 and 96 h after treatment, compared to the control. Adult emergence and female longevity were also reduced at LC30. The LC30 of lufenuron negatively affected reproduction of G. pyloalis. Larval content of carbohydrate and protein were decreased significantly 48 and 72 h after treatment, however, lipid and glycogen content were decreased significantly only 72 h after treatment at LC10, LC30 or LC50. Findings indicated adverse effects on some biological and biochemical parameters at lethal and sublethal concentrations of lufenuron which necessitate further investigations for its application in an integrated management of G. pyloalis.
Volume 5, Issue 2 (2-2019)
Abstract
Aims: The use of medications with plant origin covers a wide variety of maladies and constitutes an alternative way to antibiotic therapy, which seems to be no longer promising due to the widespread antibiotics resistance among the pathogenic microorganisms.
Active principles having antimicrobial activity could be extracted and purified from plants and used in developing new medications. Among several diseases which have historically scourged man, some of the gram-negative bacteria are potentially epidemic and considered as one of the most outstanding causes of diarrhea. Therefore, this study aimed to evaluate the antibacterial activity of Thymus kotschyanus extracts.
Materials & Methods: The antimicrobial effect of T. kotschyanus Boiss leaves extract on some gram-negative bacteria strains was assayed in vitro by the disk diffusion technique. Dried and crushed plant materials were extracted from distilled water by evaporation and distillation. Finally, the antimicrobial assays were carried out for the plant, and the results were compared with an ampicillin disk results.
Findings: Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Salmonella typhimurium, Entrobacter cloacae, Proteus mirabilis, and Shigella dysenteriae were apparently killed by the extract, as judged by the presence of growth inhibition halos in the assays.
The results of minimum inhibitory concentrations (MICs) showed that E. coli and E. cloacae strains were better inhibited by the extract.
Conclusion: The above results were similar to those from ampicillin disk, suggesting that T. kotschyanus Boiss could be used as a source of active principles against some gram-negative bacteria. Therefore, the tested Thymus extract could be considered as a valuable natural antibacterial source, which seems to be applicable in both medicine and food industry.
Volume 8, Issue 4 (1-2009)
Abstract
This paper examines the calendar anomalies in daily return of the Tehran stock market. ARCH and GARCH models are employed to capture the wide range of different calendar anomalies exist in the literature. This study finds the evidence of strong Esfand and Mehr effects in the stock return. In addition, the results show that the stock market return has decreased with the lapses of time. After identifying and removing the calendar effects from daily return, BDS statistic is used to test the presence of any remaining non-linearity in the residuals before employing the GARCH models. The BDS test shows that there is a high probability of the dependency between residuals in spite of removing calendar anomalies. The results confirm that both the ARCH and GARCH models have considerable success in modeling dependencies. Finally, the importance of calendar effects in return forecasting is tested. The conclusion is that the inclusion of calendar effects improves the forecast accuracy. However, simple regression which includes calendar effects has better performance than the GARCH (1, 1) models.
Volume 8, Issue 4 (3-2019)
Abstract
The nature of people-environment relationships is reflected in multiple research paradigms of the field, including studies of environmental stress, cognitive mapping, environmental assessment, human spatial behavior, resource conservation behaviors, and ecological psychology. The environment in which man and human life are surrounded affects human behaviors, senses, and perceptions. In this case, the built physical environment, particularly in cities is the most important part of human living spaces. These spaces can affect citizen’s life in various ways. Some of them grow out of the meaning of places, some of them are dealt with their physical features and some are concerned with the functions of the environment. Almost everywhere, urban religious spaces such as play a crucial role in human life. Need to pray and need to have an enthusiasm social life are of almost everybody’s spiritual needs. So due to meet, these essential needs, religious places have been established. In Islamic countries, mosques are of the main urban religious places, they serve as places where Muslims can get together for salat (Prayer) as well as for getting information, education, and dispute settlement. The main question of the present research is, whether attending in religious places can affect the citizens’ behavior or not? It seems that there are meaningful relations between attending in religious places and citizens’ behaviors. In order to examine the above hypothesis, two mosques (Hazrat-e Amir al-momenin Mosque and Hazrat-e Abolfazl Mosque) were selected as the case study. These mosques are located respectively in the regions 18 and 2 in the city of Tehran. Then the variables were determined and defined. There were two main variables in this paper. To evaluate the first variable (Attending in a religious place) some indexes were determined. Also, evaluate the second variable (Citizens’ behaviors) several indexes were chosen. Due to describe the variable of human behavior, the characteristics of human behavior have been divided into 2 parts, Social and individual, then to assess these features some indexes such as participation, philanthropy, self-confidence, social trust and etc, have been chosen. Then a questionnaire was prepared and data were collected. Finally, the responses were analyzed by SPSS 17. Based on the results, the hypothec of the investigation was accepted. It means that in the area under study there is a meaningful relation between attending in religious places and citizen’s behaviors.
Volume 9, Issue 1 (4-2009)
Abstract
Nowadays housing is not considered merely as a matter of shelter anymore. But it is also considered as a political and economic commodity. Not only housing is one of the most important assets for householders, who hold it to accept higher risks in financial markets, but also it is an indispensable good without any substitute. Recent decades, housing sector has encountered inflationary recessions and booms along with interminable price growth in Iran. This inflation rate is as a result of excessive increases in liquidity, which is due to the spending of oil dollars. However, the inflation rate may be controllable in consumption and tradable goods by some leverages such as imports while it is not controllable in nontradable goods such as housing and land. Consequently, it brings about severe and unpredictable volatilities in the price of this critical sector. In this article, we study the major determinants of housing sector with special emphasis on the relationship between oil shocks and housing inflation. The findings show that during the period 1973 to 2005 the effect of the population growth rate, liquidity growth rate, the growth rate of loans paid by Bank Maskan and (positive and negative) oil shocks on housing inflation are statistically significant and consistent with the theory while the effect of inflation rate on housing inflation is statistically insignificant.
Volume 9, Issue 1 (12-2020)
Abstract
The two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae) is one of the most important pest species, with an extended range of host plants in the world. Use of chemical acaricides is one of the principle ways of controlling this pest. Considering the resistance to acaricides, as well as undesirable effects of chemical compounds, finding a suitable alternative way to control this pest is necessary. In this study sublethal effects of Dayabon®, a herbal extract, were investigated on some biological parameter of T. urticae at 2.140 g/l (LC5), 2.682 g/l (LC10) and 3.526 g/l (LC20). The estimated LC50 for T. urticae adult was 5.950 g/l. When adults were treated with LC10 and LC20 of Dayabon, the oviposition period was significantly reduced compared to LC5. The highest and the lowest fecundity (number of eggs laid per female) were 56.02 offspring/individual in control and 39.11 offspring/individual at LC20 respectively. In addition the net reproductive rate (R0) was decreased as concentration increased. Whereas, intrinsic rate of increase (r) and finite rate of increase (λ) were not affected by Dayabon. Considering the detrimental effects of Dayabon on some biological parameters of T. urticae, it can be concluded that this product can be used to develop targeted interventions aimed at integrated management of T. urticae.
Volume 9, Issue 3 (5-2020)
Abstract
Pseudomonas tolaasii Paine and Ewingella americana Grimont are considered as devastating pathogens in mushroom cultivation. Due to the short shelf life of button mushrooms, safe methods should be used to control these pathogens to avoid any toxic residues on the products. Plant secondary metabolites are assumed as important sources for biopesticides development. The aim of this study was to screen plant species for antibacterial properties against P. tolaasii and E. americana. Antibacterial activity of aqueous extract of 17 plant species on two pathogens was investigated in vitro using the disc diffusion method at 10 and 20 mg active ingredients per disc. Then the effect of extracts possessing antibacterial activity was tested on mycelial growth of button mushroom Agaricus bisporus (Lange) using the disc diffusion method. Analysis through measuring the diameter of growth inhibition zones revealed that the extract of Hymenocrater longiflorus Benth. and the other extracts including H. longiflorus, Achillea millefolium L., Eucalyptus sp. and Teucrium polium L. had significant antibacterial activity on E. americana and P. tolaasii, respectively. However, they had no inhibitory activity on mycelial growth of A. bisporus. The efficacy of four mentioned extracts was evaluated in the control of mushroom brown blotch disease caused by P. tolaasii, in vivo. Assessment of disease severity showed that all four extracts, at tested concentrations, had some level of preventive effect on P. tolaasii with no adverse effects on A. bisporus. It is noteworthy that the strength of the A. millefolium extract at 10% did not differ significantly from the 1% household bleach in reducing the disease severity. Therefore, it is possible that some plant extracts have the power to be considered as alternatives to chemical bleaches. Moreover, findings suggest that H. longiflorus extract is a promising candidate for control of P. tolaasii and E. americana in mushroom cultivation.
Volume 9, Issue 4 (8-2020)
Abstract
The tomato leafminer, Tuta absoluta Meyrick (Lepidoptera: Gelechiidae) is one of the most damaging tomato pests in the world and in Iran. The toxicity of acetamiprid, eforia (thiamethoxam + lambda-cyhalothrin) and hexaflumuron alone and in mixture with emamectin benzoate was studied against 4th-instars of Tuta absoluta (Meyrick) at 25 ± 2 °C, 65 ± 5% RH and 16:8 (L:D) h. Moreover, the mixtures of examined insecticides with emamectin benzoate at LC15:LC15 ratio were assessed on the general esterase enzyme activity and total protein content of 4th-instars. The highest toxicity was found for emamectin benzoate after 72 h (LC50 = 0.48 mg a.i./l), followed by acetamiprid (LC50 = 46.94 mg a.i./l), eforia (LC50 = 156.24 mg a.i/l) and hexaflumuron (LC50 = 670.32 mg a.i/l). Mixing emamectin benzoate with acetamiprid at the ratio of LC50:LC50 and LC25:LC25 resulted in synergistic impacts while mix of two other ratios of the same pesticides represented additive influences. The mixture of emamectin benzoate with either hexaflumuron or eforia at all ratios created antagonistic and additive effects, respectively. Mixing emamectin benzoate with either acetamiprid or eforia increased larval esterase activity, however, there was no significant difference between emamectin benzoate in mixture with hexaflumuron and using it alone. Mixing emamectin benzoate with the examined insecticides considerably decreased the larval total protein content. Based on the findings of this work, the mixtures of eforia and acetamiprid with emamectin benzoate represented greater negative effects against 4th-instars compared to emamectin benzoate alone and the control.
Volume 9, Issue 20 (10-2005)
Abstract
The role of research in the process of economic development has been proved to be very effective and investment on research has varying effects on economic variables including value added and productivity. These impacts are of importance in industry & mine. In this paper several hypotheses are tested with the aid of various models such as Johnson & Striner, Zakazit, cobb doglas- transendental and linear models. Among them cobb doglas model has proved to be best model implying that: 1- One percent increase in per capita research expenditures in industry sectors increases per capita value added around 0/041 percent after one year. 2- The effect of physical investment of industry & mine sectors on per capita production (average per capita value added ) in these sectors is higher than research expenditure. This paper contains several parts: The first part refers to literature of the subject and examines the relevant indexes of Iran.Then it examines the trend of industrial research expenditures in Iran and some other countries and it tests relation between research expenditures and value added in industries and mines sectors. Finally it explains the problems in these sectors and provides needed proposals.
Volume 10, Issue 1 (10-2021)
Abstract
The present research was performed to evaluate the bioactivity of Citrullus colocynthis (L.) and Melia azedarach L. extracts against three major stored grain insect pests including Tribolium castaneum (Herbst), Trogoderma granarium Everts, and Sitophilus granaries (L.). Toxicity and enzyme inhibition activity of acetylcholinesterase (AChE), α-carboxylesterase (α-CE), β-carboxylesterase (β-CE), acid phosphatases (ACP) and alkaline phosphatases (ALP) in three insect species induced by both plant extracts were evaluated at four different dose rates viz., 5, 10, 15 and 20%. Results showed maximum mortality (34.29%) in S. granarius with M. azedarach at maximum interaction of time and dilution level. In T. castaneum and T. granarium maximum recorded values for mortality were 30.87% and 18.95%, respectively, with extract of M. azedarach. Plant extract of C. colocynthis reported a maximum mortality of 21.92%, 19.18% and 16.89% in T. castaneum, S. granarius and T. granarium, respectively. Findings proved that both plant extracts had decent lethal impacts on tested insect species. Exposure of studied insects to plants extracts also resulted in significant inhibition of AChE, α-CE, β-CE, ACP and ALP. All tested enzymes in three insects were maximally inhibited by plant extract of M. azedarach except α-CE which was slightly more inhibited in S. granarius and ACP which was highly inhibited in T. granarium and S. granarius, by plant extract of C. colocynthis. Outcomes exhibit that plant based extract of M. azedarach is more pronounced in stored grain insect pests and propose the capability of using these plant extracts for safety of stored commodities as a safe substitute for insecticides.
Volume 11, Issue 20 (12-2007)
Abstract
Nowaday, product quality of industrial factories ,has become the challenge for their market share in competitive world .Design of experiment (DOE), as one of the newest methods of improving quality, defines the significantly effective factors and sets their optimum levels by running the experimental design. Among all, the fractional factorial designs runs, have priority to others because of the decrease in the number of In Iran, Despite its disability in resolving interaction effects,Taguchi design as the fractional design subgroup, has been used sofar for its easy analysis. In this article, a fractional design with high- resolution degree, was defined as a case study on the refractory brick quality in Pars Refractory factory. To reach this target, the fractional design 25-1 with the high resolution degree of V,was designed and run. The results showed that controlling and setting the main interaction effects in the optimum level, lead to the minimum operation time and 41% increase in product quality. Research and development units can cause promotion in the quality of products by implementing fractional designs with suitable resolution degree and analyzing the main and especially interaction effects.