Ehsan Hma | University of Tehran (original) (raw)
Papers by Ehsan Hma
Arabian Journal of Geosciences, 2015
ABSTRACT
International Journal of Biosciences, 2014
The study investigating the impact of selected industrial effluents on some morphological and bio... more The study investigating the impact of selected industrial effluents on some morphological and biochemical characteristics of Brassica juncea. The result revealed that most of the morphological and biochemical parameters of B. juncea were negatively influenced by application of concentrated effluents. The magnitude of inhibitory effects was maximum for marble industrial effluents while it was minimum for pharma industrial effluents. The pharma industrial effluents showed growth promoting effects on B.juncea. The paper industrial effluents also showed inhibitory effects on the test plants for both morphological and biochemical parameters which was less then marble effluents. Among the selected industrial effluents the pharma was less effective that promoted some of the morphologic and biochemical parameters of B. juncea.
日本生物工学会大会講演要旨集, Sep 25, 2005
Bioscience Biotechnology and Biochemistry, May 22, 2014
Clostridium thermocellum xylanase Xyn10C (formerly XynC) is a modular enzyme, comprising a family... more Clostridium thermocellum xylanase Xyn10C (formerly XynC) is a modular enzyme, comprising a family-22 carbohydrate-binding module (CBM), a family-10 catalytic module of the glycoside hydrolases, and a dockerin module responsible for cellulosome assembly consecutively from the N-terminus. To study the functions of the CBM, truncated derivatives of Xyn10C were constructed: a recombinant catalytic module polypeptide (rCM), a family-22 CBM polypeptide (rCBM), and a polypeptide composed of the family-22 CBM and CM (rCBM-CM). The recombinant proteins were characterized by enzyme and binding assays. Although the catalytic activity of rCBM-CM toward insoluble xylan was four times higher than that of rCM toward the same substrate, removal of the CBM did not severely affect catalytic activity toward soluble xylan or-1,3-1,4glucan. rCBM showed an affinity for amorphous celluloses and insoluble and soluble xylan in qualitative binding assays. The optimum temperature of rCBM-CM was 80 C and that of rCM was 60 C. These results indicate that the family-22 CBM of C. thermocellum Xyn10C not only was responsible for the binding of the enzyme to the substrates, but also contributes to the stability of the CM in the presence of the substrate at high temperatures.
Pakistan Journal of Zoology, 2013
This study was designed to compare the effectiveness of Aluminium (Al) and Iron (Fe) as electrode... more This study was designed to compare the effectiveness of Aluminium (Al) and Iron (Fe) as electrodes to reduce the polluting nature of Palm Oil Mill Effluent (POME) and simultaneous hydrogen production using electrocoagulation (EC). Electrocoagulation of raw POME and anaerobically pretreated POME was performed using Direct Current (DC) electricity of 2.0, 3.0, and 4.0 volts in a reactor volume of 20 liters. The results of raw POME treatment reveal that the chemical oxygen demand (COD) and turbidity was decreased around 57.66% and 62.5%, respectively, using Al electrode. However, the use of iron electrodes could reduce the COD and turbidity of raw POME about 35.3% and 43.10%, respectively. The reduction in polluting factors of the raw POME was accompanied with the production of 42% and 22.8% of hydrogen gas concentration using Al and Fe electrodes, respectively. On the other hand, the results of Electrocoagulation of POME which was pretreated in anaerobic pond show that the COD was decreased around 62.35% and 59.41% using Al and Fe respectively, and turbidity was reduced up to 90.55% and 76.96% using Al and Fe respectively. The concentration of hydrogen gas yielded as a result of EC of anaerobically pretreated POME was around 31.37% and 25.6% using Al and Fe respectively as electrodes. Removal of pollutants from POME using Electrocoagulation is faster than some other existing processes and requires a relatively small area as compared to the conventional anaerobic treatment in pond system which is potential source of green house gases.
Palm oil mill effluent from the palm oil processing industry has been documented as a cause of se... more Palm oil mill effluent from the palm oil processing industry has been documented as a cause of severe damages to aquatic systems and a significant increase in greenhouse gases. This study was designed to use electrocoagulation for the pre-treatment of palm oil mill effluent to simultaneously reduce the pollutants and produce hydrogen gas. In this research, response surface methodology was applied to evaluate the effects of the main process parameters (voltage supply, retention time, and the addition of sodium chloride) in removing chemical oxygen demand, turbidity and metals from palm oil mill effluent. Response surface methodology was also applied to optimize the production of hydrogen gas from palm oil mill effluent during the electrocoagulation process. The obtained quadratic regression model has a high variance coefficient (R 2 ) value, which is greater than 85%. The optimal conditions to achieve highly efficient wastewater treatment and maximum hydrogen gas production were determined to be 4 volts, 6 hours retention time, and no added NaCl. At optimal conditions, electrocoagulation was able to remove 42.94% chemical oxygen demand (COD), 83.16% turbidity, 23.62% Fe, 27.56% Mg, and 47.83% Ca. Additionally, the production of hydrogen gas (28.87%) was also achieved, which enhances the cost effectiveness of the process.
Pakistan journal of zoology
This study was designed to compare the effectiveness of Aluminium (Al) and Iron (Fe) as electrode... more This study was designed to compare the effectiveness of Aluminium (Al) and Iron (Fe) as electrodes to reduce the polluting nature of Palm Oil Mill Effluent (POME) and simultaneous hydrogen production using electrocoagulation (EC). Electrocoagulation of raw POME and anaerobically pretreated POME was performed using Direct Current (DC) electricity of 2.0, 3.0, and 4.0 volts in a reactor volume of 20 liters. The results of raw POME treatment reveal that the chemical oxygen demand (COD) and turbidity was decreased around 57.66% and 62.5%, respectively, using Al electrode. However, the use of iron electrodes could reduce the COD and turbidity of raw POME about 35.3% and 43.10%, respectively. The reduction in polluting factors of the raw POME was accompanied with the production of 42% and 22.8% of hydrogen gas concentration using Al and Fe electrodes, respectively. On the other hand, the results of Electrocoagulation of POME which was pretreated in anaerobic pond show that the COD was dec...
Arabian Journal of Geosciences, 2015
ABSTRACT
Revue de Chirurgie Orthopédique et Traumatologique, 2010
Orthopaedics & traumatology, surgery & research : OTSR, 2010
Femoral offset is difficult to precisely evaluate with conventional X-ray techniques. Femoral off... more Femoral offset is difficult to precisely evaluate with conventional X-ray techniques. Femoral offset characterizes the balance between body weight and the resistance provided by the abductor muscles. Total hip arthroplasties should respect this balance. Computed tomodensitometry (CT-scan) is more accurate than conventional X-ray to evaluate femoral offset. Sixty-one patients who received unilateral total hip arthroplasties were prospectively included in the study. Femoral offset was measured by three-dimensional CT-scan reconstruction using the "Hip Plan" (Symbios) software. Offset was also determined with conventional X-ray and results were compared. This software can be used to measure leg length by frontal telemetry. It was developed for preoperative-planning of cementless femoral stem implants with modular necks of various lengths and angles. All pre- and postoperative measurements were made according to the same protocol. Femoral offset values in this study were very ...
Journal of Steroid Biochemistry and Molecular Biology, 1990
The binding of estradiol-horseradish peroxidase conjugate to rat uterine cytosolic estrogen recep... more The binding of estradiol-horseradish peroxidase conjugate to rat uterine cytosolic estrogen receptor was studied. The conjugate having a steroid to enzyme ratio of 2.8 : 1 was allowed to bind to protamine precipitated receptor in presence or absence of 100-fold excess of free estradiol. The bound enzyme activity was measured and the data subjected to Scatchard analysis to obtain the dissociation constant and the number of binding sites. Although the binding parameter so obtained differed from values obtained using radiolabelled estradiol, the method may be used for comparative studies.
Journal of Environmental Science and Health . Part A: Environmental Science and Engineering and Toxicology, 1992
The industrial processes in the investigated area include ferrous and non‐ferrous metallurgical w... more The industrial processes in the investigated area include ferrous and non‐ferrous metallurgical work, ceramics, fire bricks, cement industry.. etc. Soil, weeds, vegetation and dust samples were collected and analysed for several heavy metals. High levels of Pb, Cd, Ni, Cr, Mn and zinc found in the soil close to a lead, zinc smelter. In the heavy contaminated area concentrations of
Bacteriology Journal, 2011
Bacteriology Journal, 2011
Journal of Biological Research-Thessaloniki, 2014
Despite being more popular for biofuel, microalgae have gained a lot of attention as a source of ... more Despite being more popular for biofuel, microalgae have gained a lot of attention as a source of biomolecules and biomass for feed purposes. Algae farming can be established using land as well as sea and strategies can be designed in order to gain the products of specific interest in the optimal way. A general overview of the contributions of Algae to meet the requirements of nutrients in animal/aquaculture feed is presented in this study. In addition to its applications in animal/aquaculture feed, algae can produce a number of biomolecules including astaxanthin, lutein, beta-carotene, chlorophyll, phycobiliprotein, Polyunsaturated Fatty Acids (PUFAs), beta-1,3-glucan, and pharmaceutical and nutraceutical compounds which have been reviewed with respect to their commercial importance and current status. The review is further extended to highlight the adequate utilization of value added products in the feeds for livestock, poultry and aquaculture (with emphasis in shrimp farming).
Smart Grid and Renewable Energy, 2014
The Power Quality (PQ), security, reliability etc., are the prime objectives of the power system.... more The Power Quality (PQ), security, reliability etc., are the prime objectives of the power system. The protection is developed in such a way that it should be selective, fast, reliable and the cost effective. The study about the islanding protection in Low Voltage (LV) CIGRE distribution and networks like this has been proposed in this paper. This is achieved by developing the protection against the short circuit faults which might appear at the Medium Voltage (MV) bus. The protection of the network with significant penetration of the Distributed Generations (DGs) is a complicated process. The DG units which are directly connected to the grid such as synchronous or induction generators contribute large short power, whereas the DG units which are connected to the grid via inverters carry small amount of the short circuit power. This creates the problems in the protection of the network. If the proper protection coordination measures have not been taken, it might cause the malfunction of the protection devices which put the portion of the power network into the security threats. The selection of the islanding protection devices in this paper is made to protect the network against bi-directional currents at the time of short circuit fault. The LV CIGRE distribution network will enter into islanding if a fault is cleared at the MV bus by the proposed islanding protection devices. It is therefore, essential to detect the islanding in the CIGRE power network. The detection of the island in this network is another major objective of this paper. The detection of the island is proposed by using the technique which is based on the voltage phase angle difference. The simulations are carried out by using DIgSILENT power factory software version 15.0.
Planta Medica, 1987
Kew Gardens 250th - Plants, people, possibilities Skip to content: ...
Journal of Environmental Quality, 2011
Arabian Journal of Geosciences, 2015
ABSTRACT
International Journal of Biosciences, 2014
The study investigating the impact of selected industrial effluents on some morphological and bio... more The study investigating the impact of selected industrial effluents on some morphological and biochemical characteristics of Brassica juncea. The result revealed that most of the morphological and biochemical parameters of B. juncea were negatively influenced by application of concentrated effluents. The magnitude of inhibitory effects was maximum for marble industrial effluents while it was minimum for pharma industrial effluents. The pharma industrial effluents showed growth promoting effects on B.juncea. The paper industrial effluents also showed inhibitory effects on the test plants for both morphological and biochemical parameters which was less then marble effluents. Among the selected industrial effluents the pharma was less effective that promoted some of the morphologic and biochemical parameters of B. juncea.
日本生物工学会大会講演要旨集, Sep 25, 2005
Bioscience Biotechnology and Biochemistry, May 22, 2014
Clostridium thermocellum xylanase Xyn10C (formerly XynC) is a modular enzyme, comprising a family... more Clostridium thermocellum xylanase Xyn10C (formerly XynC) is a modular enzyme, comprising a family-22 carbohydrate-binding module (CBM), a family-10 catalytic module of the glycoside hydrolases, and a dockerin module responsible for cellulosome assembly consecutively from the N-terminus. To study the functions of the CBM, truncated derivatives of Xyn10C were constructed: a recombinant catalytic module polypeptide (rCM), a family-22 CBM polypeptide (rCBM), and a polypeptide composed of the family-22 CBM and CM (rCBM-CM). The recombinant proteins were characterized by enzyme and binding assays. Although the catalytic activity of rCBM-CM toward insoluble xylan was four times higher than that of rCM toward the same substrate, removal of the CBM did not severely affect catalytic activity toward soluble xylan or-1,3-1,4glucan. rCBM showed an affinity for amorphous celluloses and insoluble and soluble xylan in qualitative binding assays. The optimum temperature of rCBM-CM was 80 C and that of rCM was 60 C. These results indicate that the family-22 CBM of C. thermocellum Xyn10C not only was responsible for the binding of the enzyme to the substrates, but also contributes to the stability of the CM in the presence of the substrate at high temperatures.
Pakistan Journal of Zoology, 2013
This study was designed to compare the effectiveness of Aluminium (Al) and Iron (Fe) as electrode... more This study was designed to compare the effectiveness of Aluminium (Al) and Iron (Fe) as electrodes to reduce the polluting nature of Palm Oil Mill Effluent (POME) and simultaneous hydrogen production using electrocoagulation (EC). Electrocoagulation of raw POME and anaerobically pretreated POME was performed using Direct Current (DC) electricity of 2.0, 3.0, and 4.0 volts in a reactor volume of 20 liters. The results of raw POME treatment reveal that the chemical oxygen demand (COD) and turbidity was decreased around 57.66% and 62.5%, respectively, using Al electrode. However, the use of iron electrodes could reduce the COD and turbidity of raw POME about 35.3% and 43.10%, respectively. The reduction in polluting factors of the raw POME was accompanied with the production of 42% and 22.8% of hydrogen gas concentration using Al and Fe electrodes, respectively. On the other hand, the results of Electrocoagulation of POME which was pretreated in anaerobic pond show that the COD was decreased around 62.35% and 59.41% using Al and Fe respectively, and turbidity was reduced up to 90.55% and 76.96% using Al and Fe respectively. The concentration of hydrogen gas yielded as a result of EC of anaerobically pretreated POME was around 31.37% and 25.6% using Al and Fe respectively as electrodes. Removal of pollutants from POME using Electrocoagulation is faster than some other existing processes and requires a relatively small area as compared to the conventional anaerobic treatment in pond system which is potential source of green house gases.
Palm oil mill effluent from the palm oil processing industry has been documented as a cause of se... more Palm oil mill effluent from the palm oil processing industry has been documented as a cause of severe damages to aquatic systems and a significant increase in greenhouse gases. This study was designed to use electrocoagulation for the pre-treatment of palm oil mill effluent to simultaneously reduce the pollutants and produce hydrogen gas. In this research, response surface methodology was applied to evaluate the effects of the main process parameters (voltage supply, retention time, and the addition of sodium chloride) in removing chemical oxygen demand, turbidity and metals from palm oil mill effluent. Response surface methodology was also applied to optimize the production of hydrogen gas from palm oil mill effluent during the electrocoagulation process. The obtained quadratic regression model has a high variance coefficient (R 2 ) value, which is greater than 85%. The optimal conditions to achieve highly efficient wastewater treatment and maximum hydrogen gas production were determined to be 4 volts, 6 hours retention time, and no added NaCl. At optimal conditions, electrocoagulation was able to remove 42.94% chemical oxygen demand (COD), 83.16% turbidity, 23.62% Fe, 27.56% Mg, and 47.83% Ca. Additionally, the production of hydrogen gas (28.87%) was also achieved, which enhances the cost effectiveness of the process.
Pakistan journal of zoology
This study was designed to compare the effectiveness of Aluminium (Al) and Iron (Fe) as electrode... more This study was designed to compare the effectiveness of Aluminium (Al) and Iron (Fe) as electrodes to reduce the polluting nature of Palm Oil Mill Effluent (POME) and simultaneous hydrogen production using electrocoagulation (EC). Electrocoagulation of raw POME and anaerobically pretreated POME was performed using Direct Current (DC) electricity of 2.0, 3.0, and 4.0 volts in a reactor volume of 20 liters. The results of raw POME treatment reveal that the chemical oxygen demand (COD) and turbidity was decreased around 57.66% and 62.5%, respectively, using Al electrode. However, the use of iron electrodes could reduce the COD and turbidity of raw POME about 35.3% and 43.10%, respectively. The reduction in polluting factors of the raw POME was accompanied with the production of 42% and 22.8% of hydrogen gas concentration using Al and Fe electrodes, respectively. On the other hand, the results of Electrocoagulation of POME which was pretreated in anaerobic pond show that the COD was dec...
Arabian Journal of Geosciences, 2015
ABSTRACT
Revue de Chirurgie Orthopédique et Traumatologique, 2010
Orthopaedics & traumatology, surgery & research : OTSR, 2010
Femoral offset is difficult to precisely evaluate with conventional X-ray techniques. Femoral off... more Femoral offset is difficult to precisely evaluate with conventional X-ray techniques. Femoral offset characterizes the balance between body weight and the resistance provided by the abductor muscles. Total hip arthroplasties should respect this balance. Computed tomodensitometry (CT-scan) is more accurate than conventional X-ray to evaluate femoral offset. Sixty-one patients who received unilateral total hip arthroplasties were prospectively included in the study. Femoral offset was measured by three-dimensional CT-scan reconstruction using the "Hip Plan" (Symbios) software. Offset was also determined with conventional X-ray and results were compared. This software can be used to measure leg length by frontal telemetry. It was developed for preoperative-planning of cementless femoral stem implants with modular necks of various lengths and angles. All pre- and postoperative measurements were made according to the same protocol. Femoral offset values in this study were very ...
Journal of Steroid Biochemistry and Molecular Biology, 1990
The binding of estradiol-horseradish peroxidase conjugate to rat uterine cytosolic estrogen recep... more The binding of estradiol-horseradish peroxidase conjugate to rat uterine cytosolic estrogen receptor was studied. The conjugate having a steroid to enzyme ratio of 2.8 : 1 was allowed to bind to protamine precipitated receptor in presence or absence of 100-fold excess of free estradiol. The bound enzyme activity was measured and the data subjected to Scatchard analysis to obtain the dissociation constant and the number of binding sites. Although the binding parameter so obtained differed from values obtained using radiolabelled estradiol, the method may be used for comparative studies.
Journal of Environmental Science and Health . Part A: Environmental Science and Engineering and Toxicology, 1992
The industrial processes in the investigated area include ferrous and non‐ferrous metallurgical w... more The industrial processes in the investigated area include ferrous and non‐ferrous metallurgical work, ceramics, fire bricks, cement industry.. etc. Soil, weeds, vegetation and dust samples were collected and analysed for several heavy metals. High levels of Pb, Cd, Ni, Cr, Mn and zinc found in the soil close to a lead, zinc smelter. In the heavy contaminated area concentrations of
Bacteriology Journal, 2011
Bacteriology Journal, 2011
Journal of Biological Research-Thessaloniki, 2014
Despite being more popular for biofuel, microalgae have gained a lot of attention as a source of ... more Despite being more popular for biofuel, microalgae have gained a lot of attention as a source of biomolecules and biomass for feed purposes. Algae farming can be established using land as well as sea and strategies can be designed in order to gain the products of specific interest in the optimal way. A general overview of the contributions of Algae to meet the requirements of nutrients in animal/aquaculture feed is presented in this study. In addition to its applications in animal/aquaculture feed, algae can produce a number of biomolecules including astaxanthin, lutein, beta-carotene, chlorophyll, phycobiliprotein, Polyunsaturated Fatty Acids (PUFAs), beta-1,3-glucan, and pharmaceutical and nutraceutical compounds which have been reviewed with respect to their commercial importance and current status. The review is further extended to highlight the adequate utilization of value added products in the feeds for livestock, poultry and aquaculture (with emphasis in shrimp farming).
Smart Grid and Renewable Energy, 2014
The Power Quality (PQ), security, reliability etc., are the prime objectives of the power system.... more The Power Quality (PQ), security, reliability etc., are the prime objectives of the power system. The protection is developed in such a way that it should be selective, fast, reliable and the cost effective. The study about the islanding protection in Low Voltage (LV) CIGRE distribution and networks like this has been proposed in this paper. This is achieved by developing the protection against the short circuit faults which might appear at the Medium Voltage (MV) bus. The protection of the network with significant penetration of the Distributed Generations (DGs) is a complicated process. The DG units which are directly connected to the grid such as synchronous or induction generators contribute large short power, whereas the DG units which are connected to the grid via inverters carry small amount of the short circuit power. This creates the problems in the protection of the network. If the proper protection coordination measures have not been taken, it might cause the malfunction of the protection devices which put the portion of the power network into the security threats. The selection of the islanding protection devices in this paper is made to protect the network against bi-directional currents at the time of short circuit fault. The LV CIGRE distribution network will enter into islanding if a fault is cleared at the MV bus by the proposed islanding protection devices. It is therefore, essential to detect the islanding in the CIGRE power network. The detection of the island in this network is another major objective of this paper. The detection of the island is proposed by using the technique which is based on the voltage phase angle difference. The simulations are carried out by using DIgSILENT power factory software version 15.0.
Planta Medica, 1987
Kew Gardens 250th - Plants, people, possibilities Skip to content: ...
Journal of Environmental Quality, 2011