Showing 323 results for Chemical
Volume 0, Issue 0 (1-2024)
Abstract
Tomato is attributed as a global host for root-knot nematode (Meloidogyne incognita) soliciting ponderous damage. Using biocontrol agents to control plant parasitic nematodes is a well-established, green approach in advance of synthetic nematicides. The role of Bacillus spp. in inciting physiological and biochemical alterations in nematode infestation is discussed in the present study. The susceptible (PKM-1) and resistant (Hisar Lalit) tomato cultivars treated with Bacillus pumilus augmented the shoot length, root length and biomass of plants compared to the standard check, Pseudomonas fluorescens, followed by B. megaterium. Accordingly, all the biocontrol agent-treated susceptible plants showed reduced galling and exhibited a root gall index of 3 (moderately resistant). Contrarily, all the resistant plants showed highly resistant reactions. B. pumilus showed the topmost expression of all the biochemical enzymes like peroxidase (PO), polyphenol oxidase (PPO), catalase (CAT), phenylalanine ammonia-lyase (PAL) and total phenols. Conclusively, B. pumilus was found to be the most potential in reducing nematode infestation by embellishing the plant growth and enhancing defense-related enzymes in tomatoes.
Volume 1, Issue 1 (3-2013)
Abstract
Prangos ferulacea (L.) Lindl. (Umbelliferae family) is a dominant species in the some partial of habitats in Zagros Mountains. According to ethno-botanical studies, this plant is one of the best range plants of Iran. Local ranchers collect green Prangos while it is toxic. They then dry the plant and use it to feed their livestock, especially in winter season. This research done to analyse the changes in the chemical composition of Pr. ferulacea with the effects of time, location and type of secondary metabolisms. Therefore, the ingredients and amounts of the essential oils of Prangos were studied during the growing and flowering stages (in both green/fresh and dried forms) to track such changes. The results showed that the amounts of terpinolene, β-phellandrene and bornyl acetate were decreased in the dried form, and some of the harmful components, such as α-pinene, β-pinene, myrcen and delta-3-carene, were absent, rendering the plant non-toxic. These results confirm the opinion of the ranchers. In the growing stage, the amount of coumarin was significantly less than in the flowering stage, which also supports the conduct of the local ranchers who gather the plants at the most appropriate time.
Volume 1, Issue 2 (3-2018)
Abstract
The main aim of this paper is to analysis of chemical performance of hydrogen peroxide based on numerical and parametric methods. The proper chemical function of the catalytic bed, as one of the components of monopropellant thruster, plays a significant role in achieving the two design main goals in (minimizing mass and maximizing the specific impulse). To this end, the effect of catalyst diameter (granules) on the bed chemical performance, optimal length and pressure drop, simulations for beds with different catalytic pellet diameters have been made to 0.4-0.9 cm diameters. Hydrogen peroxide with a concentration of 90% is defined as an inlet fluid at 0.014 m/s in simulations. The calculation of flow pressure drop across the catalyst bed is one of the activities undertaken in this study. The results of this study indicate that with increasing the pellet diameter, the reaction effective surface is reduced and the catalyst bed length is increased for complete decomposition of the propellant. In addition to the required length for complete decomposition of hydrogen peroxide, the pressure drop in various catalyst beds have also been calculated and evaluated. The results of the catalytic bed drop evaluation indicate that at a specific flow rate, a minimum pressure drop will be made in a specific diameter. The reason for this is the interaction of reaction surface and catalyst bed lengths on the pressure drop generated during the propellant decomposition process. Verification and validation of achieved results was conducted by comparing with experimental results.
Volume 1, Issue 3 (9-2013)
Abstract
Some Biochemical properties of silver carp surimi prepared by application of acid-alkali aided methods were investigated and compared to that of derived by conventional method. In terms of total protein solubility and recovery, lipid reduction, and total pigment extractability and myoglobin removal there was a significant (P<0.05) difference among the treatments. Acid-aided method showed the most efficiency to recover more proteins (86.2%) in comparison to the alkaline-aided (79.8%) and conventional (76.7%) methods. The lipid reduction percentage was recorded as 43.6%, 58.4% and 72.3% for the conventional method, and acid-alkali aided methods, respectively. In terms of total pigment removal, the conventional method showed higher efficiency (P<0.05) compared to the pH-shifting methods. Conversely, fish protein solubilisation by acid-alkali aided techniques was more efficient (P<0.05) compared to the conventional method of making surimi. In conclusion, pH-shifting techniques were superior in comparison with the conventional method in order to recover more functional proteins and to efficiently reduce the lipid and myoglobin content of resultant fish protein isolate.
Volume 1, Issue 3 (9-2013)
Abstract
Landslides are natural disasters that annually inflict great damages to public and private properties which may associate with loss of life. In recent decades, research on developing methods for predicting the time of landslide has been one of the significant attempts made by scientists. Since in some type of material, landslides are preceded by undetectable movements that cannot be recorded and revealed by conventional instruments, recording the chemical changes of the water flowing out from the toe of the slopes susceptible to sliding can provide important and reliable indicators of landslide activities and early warning. In this study, changes in the chemical composition of water seeping out from the toe of an active landslide were investigated. This process was studied in a laboratory physical model, in which a sliding surface was simulated and the changes in the ion concentration of potassium (K), sodium (Na), magnesium (Mg), calcium (Ca), sulfate (SO4), chlorine (Cl), and bicarbonate as well as EC and pH in both stable state and in the conditions of slight rupture along the sliding surface were investigated. The results indicated that the appreciable chemical changes in the outflowing water, particularly changes in the concentration of some ions, could be used as suitable indicators for early warning of the landslide occurrence.
Volume 1, Issue 3 (9-2023)
Abstract
The current study suggests the utilization of steel wool as an extended anode electrode in an electrochemical process to enhance the efficiency of Remazol Brilliant Blue R (RBBR) removal from wastewater. The effect of the operating parameters of initial pH, applied current, supporting electrolyte, and initial dye concentration on textile dye removal efficiency was investigated to determine the optimum conditions of the process. Kinetic studies were performed in the optimum conditions. Scanning electron microscopy (SEM) and x-ray fluorescence (XRF) were carried out to determine the morphology and characterization of the extended anode surface. Under the optimum conditions, the dye and chemical oxygen demand (COD) removal were obtained 99.42% and 72.72%, respectively. The reaction kinetic data of the electrochemical process was followed by the pseudo-second-order kinetic rate equation (R2 = 0.99). These findings might be useful in treating the various pollutants in industrial wastewater.
Volume 2, Issue 3 (9-2013)
Abstract
The elm leaf beetle Xanthogaleruca luteola Müller (Coleoptera: Chrysomelidae), is a serious pest of elm (Ulmus spp.) throughout Iran. In the present study, Lethal and sublethal effects of neem, Achook® containing 0.03% azadirachtin, were assessed on mortality, growth, larval weight and feeding deterrence as well as enzymatic and non-enzymatic activities of third instar larvae of the elm leaf beetle. LC50 and LC30 values of the third instar larvae 48 h post treatment were estimated to be 3.3 and 2.25 ppm respectively. Observations showed higher mortality, increase in larval duration, sterilization of adults, reduction in weight and feeding deterrence after LC30 and LC50 treatments. Biochemical analysis showed changes in the amounts of biochemical components in the treated larvae after 48 h. In the treated larvae, activity level of alanine aminotransferase, alkaline phosphatase, acid phosphatase and α-amylase as enzymatic components and urea and cholesterol as non-enzymatic ones changed significantly in LC50 and LC30 treatments. Aspartate aminotransferase, lactate dehydrogenase, protein, glycogen, and glucose levels decreased in these treatments. The activity level of detoxifying enzymes such as esterase A, esterase B and glutathione S-transferase were significantly affected. Hence, neem is suggested as a safe product that may have the potential for use as a bioinsecticide in integrated pest management of urbanelms where use of chemical insecticides are discouraged.
Volume 2, Issue 4 (3-2019)
Abstract
In this study, sonochemical synthesis was used to prepare nanostructured HZSM-5 catalysts. The three most effective ultrasound related variables including ultrasound power, irradiation time, and sonication temperature were investigated. The combined effect of these variables on relative crystallinity and mean crystal size of HZSM-5 nanocatalysts was studied using a central composite design. Higher crystallinity and lower crystal size were obtained by increasing ultrasound power, irradiation time, and sonication temperature while there was an optimum range for mentioned variables. The maximum relative crystallinity and minimum mean crystal size were obtained as 55.51% and 62.37 nm, respectively, under the optimal conditions of ultrasound power (231 W), irradiation time (21.18 min), and sonication temperature (42.68 °C). The results confirmed that sonochemical method considerably increased crysatllinity and reduced crystal size of HZSM-5 nanocatalysts at lower time. Hydrothermal method produced catalyst with full crystallinity and mean crystal size of 893 nm with 120 min aging and 48 h crystallization in autoclave while sonicated HZSM-5 catalyst with 21 min sonication and 4 h crystallization has 55.51% crystllinity and 62.37 nm mean crystal size. On the other hand, no HZSM-5 phase was formed in hydrothermal method with 120 min aging and 4 h crystallization in autoclave. These results strongly suggests that a catalyst with smaller crystal size, higher crystallinity and BET surface area at lower crystallization time can be obtained by using ultrasound instead of aging step in HZSM-5 synthesis
Volume 2, Issue 7 (12-2005)
Abstract
For investigation of potato starch properties , six potato cultivars were grown in Agricultural Research Field of Gorgan in 1381-2. Starches were extracted from these tubers and their physico-chemical properties were investigated in comparison with wheat starch. Dry matter and starch content and starch yield of potatoes were found to vary from 17.2–22, 10.6–14.6 and 9.2-12.6 % (on fresh weight basis) and the maximum and minimum of these values related to Concord and Deraga varieties, respectively. No significant difference was found at reducing sugars among fresh potatoes., Phosphorus content, viscosity and mean particle size were different among cultivars and were higher wheat starch , but amylose and protein content had no significant difference in potato starches whereas protein content of wheat starch was higher than potato starches.
Volume 3, Issue 1 (12-2003)
Abstract
In this research using the theory of Induction Motor (UM), a UM with liquid as secondary part is planned and manufactured. The main objective for planning of this motor is to investigate the possibility of chemical liquids pumping such as liquid poison and acids.
Results of many laboratory tests are shown to conclude that pumping force in the manufactured pump is dependent on many factors such as the magnetic characteristics of material of primary side and the electrical conductivity of liquid. In high magnetic permeability and high electrical conductivity, pumping force is fortified. Thus using the proposed method, pumps without mechanical moving parts can be manufactured.
Volume 3, Issue 2 (9-2014)
Abstract
The effect of pistachio green hull (PGH) at 0, 1.5, 4.5, 13.5 and 27% of the diet on the growth, blood biochemical and hematological parameters of rainbow trout (Oncorhynchus mykiss) of 27.03±0.58 g was investigated in a completely randomized design and in three replications with 14 fish individuals in each. At the end of 8 weeks feeding trial, blood samples were randomly taken from 4 individulas in each replication. Results showed significant differences (p<0.05) in SGR and FCR between 27% treatment and other treatments. No significant differences in Alb, Glo, Tg, GOT (p>0.05) were observed among treatments. Tp (2.76±0.15 g/dl), LDH (2139±44.26 IU/l), ALP (331.9±21.4 IU/l), GPT (407±17.82 IU/l), Hb (8.73±0.7 g/dl) and Hct (33.33±2.28%) had significant differences in group receiving 27% PGH compared with other group (p<0.05). Results showed that high levels of PGH in the diet of rainbow trout had adverse effects on health and growth factors.
Volume 3, Issue 8 (4-2006)
Abstract
Some physico-chemical characteristics of Iranian linseed oil (Linum usitatissimum) such as oil content (44.25%), refractive index (1.47), peroxide (7.21meqO2/Kg Oil), iodine (170.67gI2/100g Oil), acid (3.10mgNaOH/g Oil) and saponification (191.73mgKOH/g Oil) values and fatty acid profile (C16:0, C18:0, C18:1, C18:2, C18:3) were studied. For preservation of ω-3 ingredients, the linseed oil that containing 43.18% of ω-3 fatty acid, were kept in frozen condition (nitrogen atmosphere and -30 º C temperatures) and its peroxide value was determined after 0, 7, 30, 60 and 90 days. Statistical analysis showed significant difference (p<5%) average amount of peroxide value only in first 7 days of storage time and its increase (8.30%) conformed to international standard.
Volume 3, Issue 8 (4-2006)
Abstract
The Effects of Partial Substitution of NaCl by KCl on Physicochemical, Sensory, Rheologyical Properties of Iranian White Cheese. Four trails of different mixture of Iranian white cheese with the ratios of NaCl/KCl: 1.50% NaCl+ 1.50%KCl, A; 1.00% NaCl+ 2.00% KCl, B; 0.75% NaCl + 2.25% KCl, C; and D as a control with 3.00% NaCl were treated by dry salting to produce low salt cheese. The quality properties such as composition (moisture content, fat, total nitrogen with dry basis, water soluble nitrogen), sensory properties (flavor and body texture), and textural characteristics (force to fracture) were measured. The treatments exhibited no significant (P>0.05) difference in the composition of cheese (moisture, fat, total nitrogen and water soluble nitrogen) after aging period. All treatments exhibited significant difference in sensory (flavor and body texture) properties. Textural properties (force to fracture) after 30 days aging showed that there was no significant (P>0.05) difference between treatments A and D.
Volume 4, Issue 1 (6-2015)
Abstract
The chemical-morphological relationships in rainbow trout, Oncorhynchus mykiss, was assessed through photography in light room. The image data were transferred to a laptop and analyzed by MATLAB (Matrix Laboratory) version R2009a. The designated algorithm of 7 features, including length, height, area, perimeter, equivalent diameter, major and minor axis length were extracted from the images. Afterward, chemical compositions of the fish (including crude protein, crude fat, moisture content, pH value and leakage), were determined. Pearson's correlation coefficient was used to correlate visual and chemical properties. Factors were assayed with linear, logarithmic, exponential and power method. Results showed that pH, leakage, protein and fat had a good correlation with fish length, and moisture with fish perimeter, in Quadratic equation (R2= 0.993, 0.991, 0.991, 0.989 and 0.992, respectively). In conclusion, this methodology can be applied for automated chemical analysis and on-line monitoring in fish farms.
Volume 4, Issue 1 (6-2015)
Abstract
Fish egg is an important source of polyunsaturated fatty acids, protein, minerals and vitamins. These are produced in the form of smoked, salted and then consumed. Initial preparations for washing eggs can have an important role on the finished product. To increase the strength of the egg membrane, waste removal, connective tissue and broken shells, fish eggs obtained after washing with different methods are carried out. In this study, three treatments have been utilized including, non-boiled water, boiled water cooled to3 to 5 °C, boiled water to 40 °C. Afterward, the two groups were prepared with 1.5% salt and no salt. Results of chemical, microbial and sensory tests were assessed on days 0, 12 and 24. It was shown that, cooled boiled water with a temperature of 3 to 5 °C with 1.5% salt and boiled water with a temperature of 40 °C with 1.5% salt gave the best and Non-boiled water with ambient temperature devoid of salt had the worst chemical andmicrobial results. In addition, cold boiled water with temperatures 3 to 5 °C with 1.5% salt showed the best sensorial results. Boiled water with a temperature of 40 °C and non-boiled water without salt had the lowest sensorial results.
Volume 4, Issue 3 (12-2015)
Abstract
This study was conducted to evaluate the effects of different levels of prebiotic GroBiotic®-A on some growth, hematological, biochemical and immunity parameters of cultured juvenile beluga (Hous huso). Four groups of beluga sturgeon with mean weight of 40.82± 5.8 g were raised for 56 days in fiberglass tanks (20 fish to each tank) and fed with different levels of GroBiotic®-A with concentrations of 0, 0.5, 1.0 and 2.0% (three replicates were used for each concentration). At the end of trial, some of the growth parameters were calculated and blood samples collected from 36 fish. Then some hematological, biochemical and immunity parameters in different groups were determined and compared with control group. Results showed that significant difference in some growth parameters, neutrophil percentage, haemoglobin (Hb), haematocrit (Hct) value and total protein (TP) in fish fed with 2.0% GroBiotic®-A were observed compared with control group (p<0.05), but no significant difference were observed in other hematological and biochemical parameters (p>0.05). The results suggest that administration of GroBiotic®-A at the level of 2.0% will be improvement some of the growth and hematological parameters and immune function of juvenile beluga. So, using of this supplement as growth promotor and immunostimulants was recommended in farmed beluga.
Volume 4, Issue 4 (12-2015)
Abstract
The bioactivity of chemical extracts from silverleaf nightshade Solanum elaeagnifolium Cav. seeds and leaves were tested for herbicidal activities, through water and ethanol extracts, against Portulaca oleracea L., Corchorus olitorius L., Convolvulus arvensis L.and Echinochloa crus-galli (L.) found in most Zea mays L.fields. Characterization of the isolated constituents from ethanol extract was conducted by various spectroscopic techniques. Purification of chloroform (100%) column fraction carried out by TLC plate using developing system; chloroform: ethanol: acetic acid (92:4:4) and hexane: chloroform: ethyl acetate (16:16:1) resulted chlorogenic acid, kaempferol and mangiferin. The second active column fraction eluted by chloroform: ethyl acetate was purified on TLC by chloroform: methanol: water (13:7:1) and butanol:water:formic acid (4:5:1) resulted in (coumaroyl glucoside, coumaroyl quince acid) and (kaempferol β-D-(6”-O-cis-cinnamoyl glucoside), dicaffeoyl quinic acids) respectively. The most active isolated component fromS. elaeagnifolium seeds was chlorogenic acid which decreased P.oleracea total biomass fresh weight by (86.5%) followed by kaempferol β-D-(6”-O-cis-cinnamoyl glucoside) (84.4%), while a moderate effect was achieved from coumaroyl glucoside (79.37%), mangiferin (76.98), kaempferol (72.48%) and coumaroyl quince acid (66.47%); finally the lowest activity (63.6%) was achieved by dicaffeoyl quinic acids compared with the controls. Thus, the herbicidal activity of these constituents suggests their potential for development as natural herbicides.
Volume 4, Issue 4 (12-2015)
Abstract
Rigidoporus microporus is a major threat to Hevea brasiliensis in the rubber growing regions of the world. In vitro synthetic fungicidesensitivity assays of Tridemorph, Benomyl and Bayfidan at seven different concentrations, and in vivo effectiveness of the three fungicides on R. microporus inoculated on rubber seedlings were evaluated. The three chemical fungicides used in this study were effective on R. microporus, with Tridemorph being the most effective. The minimum inhibitory concentration value for Bayfidan was between fungicide concentrations of 0.001µg/ml and 0.005µg/ml. Percentage of plant death and presence of rhizomorph recorded at two months after inoculation were higher than that recorded at the termination of five months experimental period after inoculation. Tridemorphtreatment had the highest plant health both at two months and at five months after inoculation. Decline in plant death from the third months onward suggested a reduction in fungal activity of R. microporus. Tridemorph was most effective among the three fungicides tested as it exhibited higher mycelial percentage inhibition in the management of R. microporus in vitro and higher plant health of rubber seedlings in vivo.
Volume 4, Issue 4 (3-2016)
Abstract
The effect of metal ions, surfactant, oxidizing agents and enzyme inhibitors was considered on trypsin and chymotrypsin activity of the Caspian brown trout fry. The results showed K+ and Na+ didn’t significanly decrease trypsin and chymotrypsin activity (p>0.05). Ca2+ and Mg2+ significantly increased trypsin and chymotrypsin activity (p<0.05). Mn2+,Cu2+,Ba2+,Co2+,Zn2+,Fe2+ and Al3+ significantly decreased the activity of trypsin and chymotrypsin (p<0.05). Saponin and taurocholic acid significantly increased trypsin and chymotrypsin activity. Sodium cholate significantly increased chymotrypsin activity (p<0.05), but not the trypsin activity (p>0.05). Oxidizing agents, including hydrogen peroxide and sodium perborate, significantly decreased trypsin (p<0.05). Trypsin and chymotrypsin activity significantly decreased in the presence of SBTI, PMSF and ρ-Aminobenzamidine inhibitors (p>0.05). The inhibitors such as TPCK, pepstatinA, iodoacetic acid, EDTA and ß-mercaptoethanol did not significantly decrease the trypsin activity (p>0.05), but they significantly decreased chymotrypsin activity (p<0.05). Trypsin activity in the presence of TLCK showed a significant decrease (p<0.05), but TLCK and pepstatin A had no significant effect on chymotrypsin activity (p>0.05).
Volume 4, Issue 15 (12-2007)
Abstract
Introduction and cultivation of new oilseeds, is an important step to provide needed oil for the country. Milk thistle (Silybum marianum) is an annual or biennial plant that the extract of its leaf or seed has been used for treatment of liver diseases since 2000 years ago. In spite of compatibility of this plant to climate of Iran especially resistance to dryness, there is no information about the content and quality of the seed oil. In this study, the oil content was determined by Soxhlet and it was 22.7%, nearly similar to soybean and cottonseed(dehulled) oil content. Refractive index, Color and Specific gravity and Peroxide(1.59), Iodine(109.57), Saponification(180.9) and Acid(1.82) values of the oil were studied. Also, fatty acid profile of the oil was determined by GC. Linoleic acid (51.2%) and oleic acid (28.8%) were the most fatty acids of the oil, respectively. In regard to remarkable oil content of the seed and high nutritional value of the oil (high-linoleic acid), cultivation of this new valuable oilseed is necessary and beneficial.