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Open Access Article
1 - Estimation of Soil Particle-Size Distribution Curve Based on Three Parametric Pedotransfer Functions
Hamid Reza FooladmandBackground and Aim: The particle-size distribution (PSD) curve is one of the most important soil properties, and many models have been presented for fittng to the measurd data of this curve. Also, there are some methods for estimating of this curve including its e MoreBackground and Aim: The particle-size distribution (PSD) curve is one of the most important soil properties, and many models have been presented for fittng to the measurd data of this curve. Also, there are some methods for estimating of this curve including its estimation using more easily available soil properties which can be called parametric pedotransfer functions. The main objective of this study was the estimation of PSD curve with some different models based on the parametric pedotransfer functions.Method: In this study, the models of Haverkamp and Parlange (1986) with two conditions, Assouline et al. (1998), and Fredlund et al. (2000) were employed for fittng to the measued data of this curve. All mentioned models contain several parameters, and the estimation of PSD curve may be accomplished by knowing the models parameters. To do this, some equations were derived for estimating the parameters of the model of Haverkamp and Parlange (1986) in two assumptions, and the model of Assouline et al. (1998). Also, the equations for estimating Fredlund et al. (2000) model were computed from Fooladmand and Mansuri (2013). All estimated equations for the model parameters have been obtained only based on soil texture data (amounts of clay, silt, sand, geometric mean and geometric standard deviation of the particle-size diameter) which are available easily and common in measuring and computing for soil samples. For this purpose, 30 soil samples were collected from different locations in Fars Province, south of Iran to calibrate the equation, and 10 soils in this area plus 30 soils of UNSODA soil data bases were used to validate the obtained results. 40 soils in validation stage have been divided into three groups containing fine, medium and course textures. The best derived equations for estimating the parameters of the model of Haverkamp and Parlange (1986) with two assumptions, and the model of Assouline et al. (1998) were obtained by using the step by step linear regression procudure. Then, the root mean square error (RMSE), geometric mean error ratio (GMER) and geometric standard deviation of the error ratio (GSDER) have been used to evaluate the obtained results in the validation stage.Results: The results indicated that the model of Fredlund et al. (2000) was appropriate for soils with fine and course textures, and the model of Assouline et al. (1998) was appropriate for soils with medium texture. Also, the results indicated that two conditions of the model of Haverkamp and Parlange (1986) were not appropriate for estimating the PSD curve. Manuscript profile -
Open Access Article
2 - Evaluating some pedotransfer functions for simulation of transient water flow in soil
Sanam Jafari Gilandeh Ali Rasoulzadeh Habib KhodaverdilooQuantitative description of soil hydraulic properties is necessary for any scheduling related to soil and water resources conservation. Soil hydraulic properties are important inputs for simulation of water flow and solute transport in soil. Since direct measurement of MoreQuantitative description of soil hydraulic properties is necessary for any scheduling related to soil and water resources conservation. Soil hydraulic properties are important inputs for simulation of water flow and solute transport in soil. Since direct measurement of these properties is time consuming and costly, pedotransfer functions (PTFs) have been widely and successfully used for their prediction. Yet, little efforts have been made for functional evaluation of PTFs predictions for application in simulating transient soil water flow. In this study, soil water retention curve (SWRC) of a clay soil was predicted, using some selected local and global PTFs. SWRC was also measured in the laboratory by direct method. Validity of studied PTFs in terms of prediction of SWRC was examined. By applying both predicted and measured hydraulic parameters to HYDRUS-1D program for simulation of soil water flow, functional behavior of PTFs was quantitatively compared in terms of simulation of water flow in soil. The obtained results indicated that both the selected global PTFs (Rosetta) with root mean square error (RMSE) < 0.025 cm3cm-3 and some regional PTFs (Ghorbani-1) with RMSE < 0.014 cm3cm-3 can reasonably well predict SWRC of soil surface. For prediction of SWRC of subsurface soil, the RMSE value of global PTFs was larger than 0.107 cm3cm-3 and was ranged from 0.036 to 0.356 cm3cm-3 for the local PTFs. However, for simulation of soil water flow a different set of PTFs was most efficient. RMSE values of adjusted Ghorbani PTF (S-Gh&H (Adj.)) for simulation of water content of surface and subsurface soils were 0.025 and 0.055 cm3cm-3, respectively. RMSE value of Wosten (1997, 1999) PTFs for surface soil was larger than 0.149 cm3cm-3 and for subsurface soil was less than 0.058 cm3cm-3. Simulation with the measured SWRC had RMSE values of 0.013-0.040 cm3cm-3 for surface and subsurface soils, respectively. It can be concluded that when validating PTFs, one should consider the objective for which the PTFs are assessed. A PTF might be accurate enough for predicting SWRC, but not for particular q(h) range governing the soil water redistribution process. Using such PTFs might lead to large errors in simulating soil water content. Manuscript profile -
Open Access Article
3 - A new strain of Rhodotrula mucilaginosa producing sophorolipid biosurfactant as an effective agent in microbial oil extraction
Zahra Ganji Keyvan Beheshti-Maal Ahmadreza Massah Zarrindokht Emami-KarvaniObjective: Biosurfactants have wide applications in the microbiology of food and oil. The aim of this research was to investigate the production of stable biosurfactant in high temperature and salinity from yeasts isolated from oil-contaminated soil.Materials and method MoreObjective: Biosurfactants have wide applications in the microbiology of food and oil. The aim of this research was to investigate the production of stable biosurfactant in high temperature and salinity from yeasts isolated from oil-contaminated soil.Materials and methods: Bushnell Haas culture medium was used to screen biosurfactant producing yeasts. The presence of biosurfactant was evaluated using oil dispersion and surface tension reduction tests.Findings: The best biosurfactant producing strain of Radotrulla mucilaginosawas named GBMEIAUF1 and its 5.8s-rDNA gene sequence was registered inthe NCBI gene bank under accession number CBS11162. The results of thin layer chromatography and Fourier transform infrared spectroscopy confirmed that the extracted biosurfactant was sophorolipid with significant surface activity. Purified sophorolipid decreased the surface tension of water from 72 mN/m to 1.29 mN/m. The highest emulsification index, E24%, the extracted biosurfactant was 53% and retained 63.71 to 58.09% of its initial activity at 80 to 120 degrees Celsius. This biosurfactant also retained 82.67 and 89.41% of its initial activity at pH 10.5, and 12, 59.66% of its initial activity at 10% salinity.Conclusion: This research is the first report of sophorolipid production by the yeast Redotrula mucilaginosa.Due to its thermal stability and high pH and salinity tolerance, sophorolipid produced by Redotrula mucilaginosa can be strongly recommended as an effective emulsifying agent for application in microbial enhanced oil extraction programs as well as food industry. Manuscript profile -
Open Access Article
4 - Theoretical investigation of 4-(2,3-dihydro[3,4-6][1,4][dioxin-5-yl) aniline copolymer
Forough Kalantari Fotooh Mohammad Reza Nateghi Mohsen Mohammadi -
Open Access Article
5 - بررسی توابع انتقالی رگرسیون چند متغیره، شبکه پرسپرترون چند لایه و توابع پایه شعاعی جهت برآورد ظرفیت تبادل کاتیونی خاکهای شمال اهواز
علی صالحی کامران محسنی فر علی غلامیبرای تخمین ظرفیت تبادل کاتیونی خاک (CEC) به روش غیر مستقیم از توابع انتقالی استفاده میشود. چون (CEC) یکی از شاخصهای مهم حاصلخیزی خاک است که به دلیل هزینهبر و وقتگیر بودن کمتر به صورت مستقیم اندازهگیری میشود. هدف از این تحقیق برآورد (CEC) خاک با استفاده از رگرسیون Moreبرای تخمین ظرفیت تبادل کاتیونی خاک (CEC) به روش غیر مستقیم از توابع انتقالی استفاده میشود. چون (CEC) یکی از شاخصهای مهم حاصلخیزی خاک است که به دلیل هزینهبر و وقتگیر بودن کمتر به صورت مستقیم اندازهگیری میشود. هدف از این تحقیق برآورد (CEC) خاک با استفاده از رگرسیون چند متغیره و شبکههای عصبی مصنوعی از روی خصوصیات زودیافت خاک میباشد. به این منظور اندازهگیریها برای 100 نمونه خاک شامل 1000 اندازهگیری شامل اندازه توزیع ذرات خاک، جرم مخصوص ظاهری، مواد آلی، آهک، تخلخل، میانگین هندسی قطر و انحراف معیار هندسی، انجام شد. پس از شناسایی دادههای پرت و حذف آنها آزمون نرمال بودن دادهها صورت گرفت. با استفاده از نرمافزار SPSS رگرسیون چند متغیره بین (CEC) و ویژگیهای زودیافت خاک برقرار شد. سپس بسط توابع انتقالی برای ظرفیت تبادل کاتیونی خاک با استفاده از پارامترهای موجود با شبکه عصبی پرسپترون چند لایه (MLP) و شبکه عصبی تابع پایه شعاعی (RBF) انجام شد. نتایج نشان داد مواد آلی و رس خاک که منابع اصلی بار منفی خاک مـیباشـند با بالاترین ضریب تبیین 0.97 در برآورد CEC نقش دارند و مدل رگرسیون چند متغیره به طور کلی با ضریب تبیین 0.87 روش نسبتا مناسبی جهت برآورد CEC میباشد و شبکه MLP، با تابع انتقال تانژانت سیگموئید در لایه میانی و تابع انتقال خطی در لایه خروجی و الگوریتم آموزشی بیزین با ضریب تبیین 97/0 و میانگین مربعات خطای013/0 قادر است CEC را با خطای کمتری برآورد کند. برای شبکه RBF ضریب تبیین برابر 55/0 و خطای 017/0 در مرحله تست شبکه بدست آمد. درمجموع با توجه به نتایج حاصل مشخص شد که MLP به دلیل اینکه برای دادههایی که به صورت خطی قابل تفکیک نیستند را میتواند بهتر متمایز کند، دارای خطای کمتر و بعد از آن رگرسیون چند متغیره بهترین مدلها در مدلسازی و تخمینCEC می باشد درصورتی که شبکه های RBF به دلیل حساس بودن به ورودیها از دقت کمی در منطقه مورد مطالعه برخوردار میباشند. Manuscript profile -
Open Access Article
6 - Low Temperature CO Sensor Based on PEDOT:PSS/Fe(II)(salen) Composite Thin Film
فرخنده عربلو نره یی Raheleh Memarzadeh Farhad Panahi Mohammad Davazdah Emami Sirus Javadpour Mohammad Hossein ShariatGas sensors are now widely used for routine monitoring of the quality of atmospheres. A sensitive PEDOT:PSS/Fe(salen) thin film based toxic gas sensor deposited on glass pieces with interdigitated Au electrodes was developed by the spin coating method. The obtained comp MoreGas sensors are now widely used for routine monitoring of the quality of atmospheres. A sensitive PEDOT:PSS/Fe(salen) thin film based toxic gas sensor deposited on glass pieces with interdigitated Au electrodes was developed by the spin coating method. The obtained composite was well characterized by different techniques such as UV–vis spectroscopy and FTIR. Also, the surface topography of thin film composite was investigated using AFM. The Fe(salen)-doped PEDOT:PSS on interdigitated electrode was experienced an immediate decrease in resistance when exposed to carbon monoxide gas under normal dry room temperature conditions (%RH=20). The results showed that the response of desired sensor was not unidirectional, and reverses to the original resistance level when CO was removed from the test chamber (RD< 2%). The highest response factor and lowest response time (t90) obtained were equal to 40±0.77% and 38s, respectively. Ultimately, the optimum level of doping (0.02 wt. % of Fe(salen)) was determined. Manuscript profile
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