s. a. mortazavi

Mechanical damage caused by foreign object damage (FOD) reduces the fatigue life of the turbine blade under resonance conditions. In this article, the results of the investigations carried out in order to determine the causes of the failure of the first row compressor blade of an industrial gas turbine sample used in Continental Plateau Oil Company are presented. At first, the images of visual inspection and borescope were examined, and the presence of sand and dust in the turbine and the observation of a hole on the leading edge of the blades adjacent to the broken blade indicate the phenomenon of foreign object damage. From the examination of the blade fracture section, the effects of fatigue and crack growth were revealed. Next, the finite element analysis of stress and vibrations was done considering the effects of FOD. In order to verify the finite element model, the modal test was performed in free-free. Finally, the Campbell diagram was extracted and the natural frequencies and critical dynamic stresses were obtained. The location of the dynamic stress concentration of the fifth mode of the blade was very consistent with the location of crack growth and blade failure.

Oxidation reactions and microorganisms’ activity are considered as the most important factors affecting the quality of food products. Recently, in the light of the inefficiency of some chemical preservatives against microorganisms and the presence of toxic residues in food products, the use of natural antimicrobials and antioxidants has been increased. Natural antimicrobial compounds have the potential to control microbial contamination and reduce the use of antibiotics. Plant essential oils are natural compounds with the potential to be used as active ingredients in the food, pharmaceutical, and cosmetic industries. Various studies have shown that essential oils have antifungal, antibacterial, antiviral, and antioxidant activity. The essential oils are considered as superb preservatives with various biological functions. Essential oils are generally recognized as safe product (GRAS) which can be used as an alternative to synthetic additives.Grapefruit (Citrus paradisi) peel and fruit contain active ingredients such as acids, flavonoids, vitamin C, and potassium, and its essential oil is composed of terpenic hydrocarbons, such as citral, limonene, citronelal, and geraniol. Although plant essential oils have antimicrobial and antioxidant properties, one of the main problems of these natural compounds is their high volatility and instability. In this context, nanoemulsion formulations are frequently used to increase the stability and efficiency of these biologically active compounds. This study is therefore aimed to nanoemulsifying the grapefruit essential oil and evaluate its antioxidant and antimicrobial properties.

β-carotene, linoleic acid, ABTS (2,2’-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt), and DPPH (2,2-diphenly-1-picrylhydrazyl) were purchased from Sigma-Aldrich Co. (USA). Mueller Hinton Broth (MHB) and Mueller Hinton Agar (MHA) were supplied from Merck Co. (Darmstadt, Germany). Grapefruit peel was dried at ambient temperature and then powdered. The obtained powder was then transferred to a Clevenger device containing 750 ml of distilled water to perform the distillation extraction (3 h). The resulting grapefruit essential oil was stored at 4 °C until use. Grapefruit essential oil was prepared using the hydrodistillation method, and then nanoemulsified. The antioxidant activity of the nanoemulsified essential oil was investigated by DPPH and ABTS  radical scavenging activity and beta-carotene/linoleic bleaching test. The nanoemulsified essential oil or methanolic (control) was mixed with DPPH solution and the mixture was then stored at ambient temperature for 30 min, in a dark place. The control sample was prepared by methanol. The absorbance of the samples was measured at 517 nm. To determine the ABTS-RS activity, the nanoemulsified essential oil was briefly charged with methanolic ABTS radical cation solution and the resulting mixture was left at room temperature for 30 min. Afterward, the absorbance was read at 734 nm. A spectrophotometric method was applied to monitor β-carotene/linoleate solution bleaching in the presence of the nanoemulsified essential oil. To do this, the absorbance of the solution was recorded at 490 nm after 120 min against the control sample at time zero and after 120 min. Antibacterial effect of the grapefruit essential oil nanoemulsion was also evaluated against Escherichia coli ATCC 25922, Salmonella typhi ATCC 6539, Pseudomonas aeruginosa ATCC 27853, Listeria innocua ATCC 33090, Staphylococcus aureus ATCC 25923, Bacillus cereus ATCC 14579, Bacillus subtilis ATCC 23857, Streptococcus pyogenes ATCC 19615, and Staphylococcus epidermidis ATCC 12228, based on disk diffusion agar, well diffusion agar, minimum inhibitory concentration, and minimum bactericidal concentration.

The results showed that the nanoemulsion of grapefruit essential oil had a remarkable antioxidant effect of 42.27 mg/ml, 33.27 mg/ml and 54.54%, respectively, based on DPPH, ABTS, and beta-carotene-linoleic acid bleaching tests. According to disk diffusion agar and well diffusion agar results, the lowest inhibition zone was related to E. coli and the highest inhibition zone was observed in L. innocua. The minimum inhibitory concentration for L. innocua and S. aureus (the most sensitive bacteria) was 25 mg/ml, and E. coli, S. typhi, and P. aeruginosa had the highest inhibitory concentration. Also, the lowest bactericidal concentration was related to L. innocua and S. aureus bacteria and the highest concentration was observed for E. coli, S. typhi and P. aeruginosa. The nanoemulsified essential oil generally exhibited greater antibacterial activity against Gram-positive species. This could be mainly due to the difference in the cell wall composition of Gram-positive bacteria in comparison to Gram-negative; Gram-positive bacteria have a thicker mucopeptide layer in their cell wall, while Gram-negative bacteria have only a thin layer of mucopeptide and the wall structure is mainly composed of lipoprotein and lipopolysaccharide, thereby leading to a higher resistant to antibacterial agents According to the results, grapefruit essential oil nanoemulsion can be used as a natural antioxidant and antimicrobial agent to control oxidation reactions and the growth of spoilage and pathogenic microorganisms.

In this paper, it is possible to change the alloy of the blades of the last row of steam turbine blades of Ahvaz Ramin power plant in order to increase the life with the vibration approach. After entering the geometric model into the ANSYS, dynamic analysis and stress analysis are performed on the model for steel alloy and titanium alloy, as well as crack growth in the single-blade model. In the dynamic analysis, the results showed that when we consider the material of the turbine blades as titanium alloy, we can create better vibration conditions in the turbine blades and prevent the possible occurrence of resonance phenomenon. Also in stress analysis, when titanium alloy is used in the blade, the Von Mises stress obtained is approximately equal to half the stress obtained from the steel alloy. When the blade cracks at the root, the amount of stress intensity calculated in the turbine blade is reduced by almost 50% when the blade is made of titanium alloy.

In this study, the effect of failure of a screw in the coupling connecting two compressor shafts on the dynamic behavior of the rotor in The Rolls Roys gas turbine has been investigated. For this purpose, the geometric model of the compressor shaft was designed and Modal analysis was performed by finite element method by ANSYS and Campbell diagram were designed separately. Experiential Modal analysis and its comparison with numerical Modal analysis have been used to validate and confirm the designed model. It used the harmonic analysis of the shaft without blades and discs, as well as the shafts with blades and discs for the frequency response of velocity and displacement due to the failure of the screw connecting the two shafts at the edge and medial connection separately and synchronous. The results showed that the frequency response of the compressor shaft velocity in the coupling screw failure at the edge of the screw failure location is about 30% higher than the medial screw failure mode, indicating that the coupling screw failure in the edge has a greater effect on the shaft and rotor behavior in terms of velocity and displacement compared to the medial screw.

Dasht-e Abbas plain is one of the most important agricultural areas of Ilam province of Iran, which has suffered environmental problems in recent years. If the new water resource management policy causes an increase in the pollution of underground water resources or in general, damage to the environment, there is no price for this damage in the market. Therefore, this study aimed at investigating the non-market value of water entering from the Karkheh dam to the Dasht-e Abbas plain aquifer using the Choice Experiment (CE) method; Also, by presenting environmental and socio-economic characteristics in a questionnaire and data collected from 108 operators, the value of non-use and indirect use of water transfer to this aquifer was estimated. The study results showed that in this aquifer, the highest amount paid was related to soil salinity and desertification with the amount of about 258 thousand IRI rials per hectare per month and the reduction of the reed area with the amount of 176 thousand IRI rials placed in the second rank; and the amount of employment with the lowest amount of willingness to pay was about 69 thousand IRI rials per hectare per month and the total willingness to pay of each reservoir operating household was about 630 thousand IRI rials per hectare per month. According to the study results, estimating the preferences expressed by farmers regarding the extracted characteristics can help planners in managing aquifers before applying any policy or program. Therefore, it is suggested that the authorities and planners of the agricultural sector pave the ground for participation of less experienced farmers in such projects by making them aware of the importance of the environment and its close relationship with their product yields,.

In this study, after the extraction of F.angulata and microalgae Spirulinaplatensis by ultrasound technique and ethanol (99/70 %), levels of 0/1 to 1% of both extracts were injected into milk samples, according to the formulation, and probiotic yogurt containing LactobacillusacidophilusLa-5 wasprepared. Then,determination of pH, color and probiotic count was donewithin 21 days. By increasing the storage time, the pH and syneresis values decreased and increased respectively.Treatments containing different levels of Chevil extract showed lower pH and more syneresis in comparsion with Spirulina extract. Regarding color parameters (L*a*b*), increasing the storage time until the 14th day, the lightness intensity (L*) decreased and the green intensity (a*) of the samples increased. From the 14th day until the end of period, the L* and a* values was increased and decreased respectively.Treatments containing F.angulata extract, had a less L* value and greater a* value than S. platensisextract. The b* value decreased over time, and the highest mean (more yellowness) was related to the treatments containing F.angulata extract. During cold storage until 14 d, L.acidophilus count increased significantly, and then, declined 1 logarithmic cycle, but it was more than the standard number in probiotic yogurt. Treatments containing S. platensisextract showed a higher count of L. acidophilus.The use of S. platensis extract in comparison with F.angulata extract, yielded better results in terms of pH, color and probiotic count. The use of both extracts could improve yogurt color and increase the probiotic count.

In this research, an industrial spray dryer was used and the effects of atomizer speed on the physicochemical properties of milk powder, the textural and sensory characteristics of white cheese made from this milk powder were evaluated. For this purpose, whole milk was converted into powder by using three different speeds (10,000, 11,000, and 12,000 rpm). The results showed that by increasing atomizer speed in the spray dryer, the average size of casein micelle is significantly decreased (P < 0.05), whereas no significant effect is observed on the chemical properties of milk powder. White cheese characteristics indicated that by increasing atomizer speed, texture parameters, such as hardness, mastication, and gumminess were significantly reduced (P < 0.05). Sensory evaluation also revealed that the cheese samples prepared with dried milk produced at 12,000 rpm were highly accepted by the panelists. Overall, the findings suggested that 12,000 rpm is the optimal atomizer speed for milk powder production.

In this research the effect of green tea extract on some qualitative and rheological properties of rosette was studied. Green tea extract with percentages of 0.5, 1 and 1.5 wet basis were used. Rosette dough rheological behavior measured by rotational viscometer at 20, 35 and 50 ° C and speeds10-200 rpm. The effect of temperature on the viscosity and stability of rosette was evaluated using the Arrhenius equation and then activation energy was calculated. The results of this research showed that with increasing temperature, viscosity significantly decreased. Mathematical calculations of finding in basis of Mitchka method showed that the rosette dough was non-Newtonian fluid and the shear thinning. Then the rosette dough was fried for two minutes at 150 ° C. Then oxidative stability index, peroxide and acid index were measured for samples. Results showed using green tea extract caused reduce the peroxide value, acid value and increase oxidative stability index. Use of green tea extract had postponed oil hydrolysis rate and increase the acid value.

The natural derived biopolymers are highly interested in recent years. These polymers are considering as the alternative for un-biodegradable plastic films. This is due to the low cost and their availability from biodegradable and renewable sources. In this study, the effect of different concentrations of Tio2 nanoparticles on physicochemical and microbiological characteristics of prepared edible films based on soy flour soluble polysaccharide was investigated.
The nanocomposite films were prepared by adding the Tio2 nanoparticles (5, 10 and 15%/ db) to the soy flour. In order to investigate the physicochemical and microbiological properties, the resulted nanocomposite films were synthetized based on the casting method.
When the content of nanoparticles increased, the moisture content and solubility of the film specimens were significantly decreased, whereas the mechanical resistance was significantly increased. Tio2 nanoparticle was highly effective against basillus cereus, staphylococus ureus and staphylococuss epidermidis. Meanwhile, MIC and MBC of molds were not affected by these films. MIC for penicilium expansum was significantly affected when the Tio2 nanoparticles increased.
the results indicated that Tio2 nanoparticles are applicable into the polysaccharide soy films. The nanocomposite film developed in the current study could be used in food applications and as a biodegradable film.

Molds have the ability to produce different pigments with consumption as food color. This study aimed to investigate the effect of the factors affecting the production of pigment by the Penicillium aculeatum. In this study، the combined effect of pH (5، 6. 5 and 8)، temperatures (25، 30 and35) and agitation speed levels (100 and 150 rpm) on pigment production and mycelial growth of Penicillium aculeatum was investigated in submerged whey media. After ten days of incubation، the produced pigment was isolated and purified using filtration، centrifugation and ethyl acetate solvent. All experi-ments were conducted in a completely randomized factorial design with three replications. The data were compared using the mean Tukey’s test and data analysis was performed using the statistical soft-ware JUMP V 8. 0. 1. The best production of pigment (1. 38 g/L) was obtained with pH value of 6. 5، temperature of 30 ˚C and agitation speed of 150 rpm. In contrast، the maximal biomass concentration (11. 12 g/L) was obtained at pH value of 8، temperature of 30˚C and agitation speed of 100rpm. These results demonstrated that biomass and pigment production were not directly associated. This study showed that the effect of pH and temperature on pigment production are significant (p<0. 05) but agita-tion speed not significant (p≥0. 05). pH has no significant effect of growth (p≥0. 05)، In contrast، tem-perature and agitation speed have a significant effect on the growth (p<0. 05).

Samanu is a traditional Iranian dessert with high nutritional value that using it as substitute of high-calorie and high-consumption foods such as breakfast chocolates and other fat spreads is important. Hence، in order to evaluate of low-fat samanu spread formulation total oil (10-30%)، vegetable oil to butter ratio (50:50-80:20%) and stabilizer content (0. 1-0. 5%) parameters were used. Effect of each parameter was studied on physicochemical properties of the spread namely moisture، pH، acidity، emulsion stability and color difference using by response surface methodology and factorial during storage at 4 ͦϹ for 14 days. Moisture، pH، emulsion stability and color difference of the spread were significantly decreased during storage however، the acidity was decreased. Carrageenan increasing in the spread formulation revealed that the sample contained more carrgeenan has less moisture and acidity but much pH، emulsion stability and color difference. As well as increasing butter compared to vegetable oil increased the all studied properties.

Acceleration of cheese ripening is interesting for researchers in the field of food technology. The purpose of this study was encapsulation of Flavourzyme in liposome by heating method and evaluation of its kinetic properties before and after encapsulation. The impact of temperature (12-62°C) and pH (7-9) was investigated on enzyme activity by central composite with 13 treatments. Liposome was prepared by modification of heating method and by phosphatidil choline، Flavourzyme and cholestrol in the amount of 4. 500، 0. 675 and 0. 225 (%w/w)، respectively. Enzyme activity was measured base on enzyme reaction with initial material of L-Leucin P nitroanilid. Kinetic studies indicated an increase in both Michaelis–Menten constant and maximum velocity in encapsulated Flavourzyme (P<0. 05). Optimum incubation temperature and pH of encapsulated enzyme did not show any significant difference in compare to free enzyme. Evaluation of the thermal stability (at 35، 45 and 55°C) showed that encapsulated enzyme was stable at 35°C during 6 h. Also a decrease of stability of encapsulated enzyme has been observed at 65 and 75°C in 1 h. The results showed increased stability of encapsulated enzymes in pH 7 and 8 (7 h)، while it was decreased in acidic condition. The results showed that liposomal encapsulation by heating method did not cause any significant difference on kinetic characteristics of enzyme Flavourzyme but comparison of proteolysis in sample and control indicated gradually proteolysis of casein in the case of liposomal enzyme application. So، it can be concluded that preparation of liposome by heating method is a suitable approach for encapsulation of protease for acceleration of cheese ripening.

Dry skin is a common problem which affects wound healing, severity of other skin diseases and quality of life of people. One of its undesirable effects is fissure that is a cutaneous condition in which there is a linear loss of epidermis and dermis with sharply defined, nearly vertical walls. In the present study, we have investigated the etiology of the disease and its treatments in conventional medicine and Iranian Traditional Medicine (ITM). Two traditional medicine references, current scientific data bases and medicinal texts were explored with the selected keywords such as "sheqaq-e-poosti", "skin fissure" and "dry skin" to find the etiology and treatment of skin fissure. From the view point of both conventional medicine and ITM, dry skin is the cause of skin fissure and some causes of dry skin are similar. In conventional medicine, moisturizers are mainly used for treatment of dry skin; while in ITM some herbs, oils and other natural remedies have been used. A topical dosage form which was called "qeirooti", a mixture of wax and oil, was used to treat skin fissure in ITM. It comprised of oily ingredients that acted as occlusives and also some herbal components that directly improved dry skin (similar to moisturizers). Components efficacy of traditional dosage forms for treatment of dry skin lead us to study about formulation of “qeirooti” for treatment of dry skin.

Burns are known as one of the most common forms of injury with devastating consequences. Despite the discovery of several antiseptics, burn wound healing has still remained a challenge to modern medicine. Herbal products seem to possess moderate efficacy with no or less toxicity and are less expensive compared to synthetic drugs. Burn is a well-known disorder in Iranian Traditional Medicine (ITM). Iranian physicians have divided burns into various types based on the cause and recommended treatment for each type. According to ITM references, herbal therapy was the major treatment prescribed by Iranian physicians for burns. In the present study, seven ancient Iranian medical texts were screened for the herbs with burn healing effects along with their applied dosage forms. The medicinal herbs were listed and scored based on the frequency of their repetition. Moreover, the best scientific name that was suitable for each plant as well as surveying modern studies about their biological effects has been carried out. In our investigation eighteen plants with seven topical application categories have been obtained as the most frequent herbs for burn healing in ITM. Modern studies have revealed that these plants have shown some biological activities such as anti-inflammatory, antimicrobial and antioxidant effects which might establish the relationship between the mentioned activities and burn wound healing property. This list can provide a suitable resource for future researches in the field of burn treatment.

Extraction of oil from poor quality pistachios results in increased add-value. In this study, the performance of different solvents in recovery of valuable oil and meal from the pistachio sample contaminated with aflatoxin was investigated and some chemical properties of the extracted oil were determined. The pistachio nut oil was extracted by three solvent systems including n-hexane (non- polar), ethanol 96˚ (polar) and n-hexane- ethanol 96˚ (90:10) using soxhlet method and for each solvent the mean yield was determined. Fatty acid profile, Iodine, peroxide and acid values of the extracted oil were determined. Aflatoxin contents in the produced oil and meal were measured. Extraction yield of the pistachio oil by different solvents ranged from 33.6% in the samples extracted by ethanol to 40.4% in the sample extracted by n-hexane-ethanol (90:10). The most predominant saturated and unsaturated fatty acids found in the pistachio oils were palmitic and oleic acids, respectively. The highest amount of aflatoxin was found in the oil extracted by ethanol and in the meal recovered by n- hexane.

According to the designed objectives for the agricultural sector and its place in developing countries، it seems that planning of multi goal programming for the same is unavoidable. The current study attempted to use goal programming to determine cropping pattern system in three structures with two priority levels. The data collected by stratified random sampling method for the year 2006-7 and 225 farmers from 30 villages randomly selected. The results showed، the goal programming respect to energy structure placed between the same respect to environmental and economic objectives. In addition، the cropping pattern respect to economic issue made gross revenue with more labor use and this carry more environmental degradation. Again address to result and place of environmental issues it may recommend asking policy makers to apply and extent the appropriate methods of farming.

Scientists have recently focused attention on the properties of natural antioxidants on pathogens and free radicals and their application in the medical and food industries. The present study evaluated the antioxidant properties of the extract of seedless barberries، a popular fruit cultivated in Iran، extracted using subcritical water as a novel technology. The phenolic compounds of the seedless barberry were extracted using subcritical water (SCW) at ratios of 1:10 to 1:30 at 50 bar constant pressure and temperatures of 120 and 180 C. The total phenolic compounds (TPC) were measured using folin ciocalteu reagent and compared with those of maceration extracts. The thermal stability of the soybean oil and the antioxidant extracts was investigated using the Rancimat method at 110C and 20 l/h air flow rate. Radical scavenging and Fe+3 reduction power of the extracts was measured to evaluate the antioxidant characteristics of the SCW extracts and they were then compared the results for ascorbic acid and BHT (300 ppm). The results were evaluated using a factorial design and LSD test at  = 0. 01 using SAS software. The TPC varied from 1729. 76 to 2848. 21 mg/100 g dry material (Gallic acid). The maximum extract yield was produced by the treatment at 120C and a 1:10 ratio. The highest antioxidant power of soybean oil was observed at 180C and a 1:10 ratio. The thermal resistance of the soybean oil with SCW extracts was very similar to that of soybean oil enriched with E vitamin as a natural antioxidant. The extracts obtained by SCW had remarkable antioxidant properties and resistance to increased temperature and reinforced the stability of the soybean oil. Subject to further study، This combination can be recommended as a good alternative frying oil in the food industry.

Agriculture is an important part of the economy having a significant role in exports of any country. On the other hand, the economic integration leads to the increase of trading and income of member states. In this paper, the factors affecting agricultural exports in ECO countries will be studied by using Panel Approach during 1992-2010. The findings present that Export Price Index, GDP and exchange rates have a positive effect and exchange rate fluctuations and population have a negative effect on agricultural exports. So, it is recommended that, for improving agricultural exports, GDP and exchange rate should be increased. In addition, by decreasing the fluctuation in exchange rate, the negative effects will be controlled.

The type of foreign policy affect on a country's economic variables and exporter surplus. Also, Pistachio is one of the most important export products and studying these markets have an important role on the earnings of exporters. In this study, factors on the export of Iran pistachios were estimated by using the ARDL approach and in Real Exchange and Nominal exchange rate. In this study, volatility of real exchange rate estimated in GARCH (1, 1) model. Result showed that the price elasticity was 1.1 and 1.6 in the real exchange rate and nominal exchange rate models, respectively. Changes in welfare surplus pistachio exporters, according to two types of price elasticity were obtained, fhich showed a surplus of pistachio exporters in the floating exchange rate policy would be much greater. Also, in log run, exchange rate volatility had a negative effect on the export product. Finally, it is suggested that floating exchange rate policy should be adopted, but the volatility of exchange rate must be reduced.

Barbus sp. fish samples were collected during November 2007 to October 2008 from five landing stations in Karoon River: Gotvand, Shoshtar, Molasani, Ahwaz, and Darkhoin. During one year of study, more than 2000 specimens of B. grypus and B. barbulus were measured, mean±SD length values for this species were 37.94±8.18 and 43.62±10.27, respectively and maximum and minimum total length were 20-76cm and 20-94cm, respectively. Mean±SD of weight values for this species were 873.2±1092.45 grams and 778.59±725.97 grams, respectively and maximum and minimum weight were 52-11170 grams and 52-4675 grams, respectively. Growth and mortality parameters were calculated for B. grypus and B. barbulus as L∞: 86.64, 132.9 and K: 0.27, 0.17 and t0: -0.46, -0.66, M: 0.50, 0.33, F: 1.22, 1.04, Z: 1.72, 2.72, 'Ф: 3.31, 3.48, E: 0.71, 0.76, respectively. According to the exploitation coefficient, B. grypus and B. barbulus stocks are overfished hence we suggest a decrease in exploitation coefficient. Based on results and their comparison with the American Fisheries Society (AFS) indices, these species are classified in moderate to high vulnerable group fishes.

According to the importance of date export in Iran, this study investigates short run and long run relationship between date export and important economical variable, specifically exchange rate. For this purpose, an autoregressive distributed lag approach (ARDL) to cointegration is applied to annually time-series data from 1981 to 2007. Results showed that the exchange rate, export price of date and agricultural value added have positive and statistically significant impacts on export value of date in both long and short-run. According to the results, it’s recommended to apply appropriate policy about exchange rate. Finally, according to estimated coefficient of the Error Correction Model (ECM), in each period 66 percent of short run imbalance toward the long-run equilibrium is adjusted.

In the literature of development economics there are two well known propositions about poverty reduction. (i); poverty can be reduced by promoting economic growth and by improving income distribution. (ii); increasing economic growth may worsen income distribution. This study attempted to investigate the relationship between inequality income and economic growth in urban and rural regions using Kuznets curve during 1980-2007 period. The results showed evidence of the inverted N-shaped relationship between per capita income and inequality of income in rural regions while, there was N-shaped relationship between per capita income and inequality income in urban areas. Also, increment in per capita income by 1 percent increased inequality of income in urban and rural areas by 0.44 and 0.41 percent respectively.

In this study, using the results of performed shale formation Characterizatins and the history of drilling in Iranian oil fields, an environmentally friendly water based drilling fluid is designed to replace the oil based drilling fluids. This drilling fluid has desirable properties in drilling water sensitive formations. New drilling fluid additives including shale inhibitors, new polymers and sized solid particles have been used to prepare this new drilling fluid. The most important properties of this new drilling fluid are controlling the mud filtrate and pressure invasion to the formation, clay mineral alteration and activity reduction, improvement of the integrity of drilling cuttings, reduction in formation damage, stability at high temperatures, stability in acidity changes and the compatibility by drilling fluids dilution during drilling operation. The lubricity and shale cuttings recovery of this new drilling fluid are better than those of other similar water based drilling fluids. Replacing this drilling fluid by oil based drilling fluids in drilling industry will be a great means to protect the environment and drilling personnel in addition to being economically advantageous.

The aim of this study was to use Alpha-amylase termamyl 2-x for maltodextrin production from corn starch and evaluate its industrial uses. Based on the results obtained in laboratory, this process was accomplished in pilot plant scale. The process included preparation of starch suspension, pH adjustment, addition of enzyme, heating under stirring, continuous control of DE and Brix, enzyme inactivation in adequate DE, separation of soluble sections by centrifuge and finally spray-drying of the maltodextrin liquid. In this investigation, the amount of DE at dry matter was calculated under three enzyme concentrations (0.2, 0.25 and 0.3 ml of Alpha-amylase termamyl 2-x per Kg of starch) and in three different hydrolysis temperatures (60, 65 and 70 ºC) at constant pH (6). A completely randomized design with factorial arrangement and 5 replications was conducted. To study the relationship between DE and different parameters, multiple linear regression was used. Finally, for approximation of DE (based on enzyme concentrations, temperatures and hydrolysis times) a regression model was used. The results from different enzyme dosages at the same temperature and time of hydrolysis differed significantly (p≤ 0.05). Meanwhile, the best enzyme concentration and hydrolysis temperature for maltodextrin (high DE) production after 300 minutes were 0.25 ml of enzyme per kg of starch and 70 ºC, respectively. In these conditions, the least residual starch concentration and residual Alpha-amylase activity were observed.

In order to determine the effects of emulsifiers (Lecithin, E471 and E472) and their levels (0, 0.25, 0.5, 0.75 and 1%) and also addition of fungal α-amylase (0, 5, 10 and 20 g/100 kg flour) on bread staling, a completely randomized experiment with factorial design and 3 replications was conducted. Bread staling was determined after 0, 24, 48 and 72 hours of storage. Correlation between variables was analyzed by simple and multivariate regression. Results indicated that addition of emulsifiers reduced the firmness of bread. E472 had the most and E471 had the least effect on bread firmness after 72 hours of storage. Addition of α-amylase reduced the bread firmness and this effect was less pronounced after 72 hours of storage. Correlation between variables based on the development of a model showed that in the first day of bread production, optimal levels of emulsifiers were 1%, 0.25% and 0.5% for Lecithin, E471 and E472, respectively. In case of simultaneous application of emulsifiers and enzyme, the optimal level of enzyme was 5 g/100 kg flour.