Manjinder Singh - Academia.edu (original) (raw)

Papers by Manjinder Singh

Color constancy is the capability to determine colors of objects independent of the color of the ... more Color constancy is the capability to determine colors of objects independent of the color of the light source. This paper deals with the different color constancy algorithms to evaluate the performance of existing color constancy algorithms. The combined effect of two color constancy algorithms i.e. White Patch Retinex (WPR) and Gray World (GW) and gamma correction used for dynamic range correction for image enhancement. The main limitation of the color constancy integrated with gamma correction proves to be efficient for dark regions but produce poor results for brighter regions. To reduce this problem in this paper we have proposed a new algorithm which will integrate the color constancy with histogram stretching and average filter to provide accurate results in dark, medium and brighter regions. The proposed algorithm is designed and implemented in MATLAB using image processing toolbox. The proposed algorithm provides significant as it has shown significantly better results in po...

space optics provides high data rate by allowing transmission of signal through atmosphere. The f... more space optics provides high data rate by allowing transmission of signal through atmosphere. The free space optics is also effected by different weather conditions. The atmospheric attenuation is caused by two main factors i.e. Absorption and Scattering. Fog, rain, snow and cloud causes the scattering of optical signals transmitted in free space. Fog is the most critical attenuating factor. The Snow Attenuation is also more severe than the Rain Attenuation due to large droplet size of snow. The hybrid FSO/RF system is considered for providing high availability. Frequencies in GHz range can improve the availability and it is selected as a back-up link. In this paper the effect of fog and snow on the performance of FSO and RF system is evaluated.

This paper presents a review on different color constancy techniques. Color constancy is the capa... more This paper presents a review on different color constancy techniques. Color constancy is the capability to determine colors of objects independent of the color of the light source. This work deal with different color constancy algorithms to evaluate the performance of existing color constancy algorithms. Different research papers are evaluated in this paper and it is found that most of existing algorithm work fine and provide efficient results. It is found that the every color constancy algorithm if follow by the gamma correction is proved to be quite efficient than available algorithms.

International Journal of Adhesion and Adhesives, 2021

Chemical Engineering Journal, 2021

Current Drug Targets, 2022

: Monoamine oxidase (MAO) is an enzyme that catalyzes the deamination of monoamines and other pro... more : Monoamine oxidase (MAO) is an enzyme that catalyzes the deamination of monoamines and other proteins. MAO’s hyperactivation results in the massive generation of reactive oxygen species, which leads to a variety of neurological diseases such as Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, Huntington's disease, and depression-like disorders. Although synthetic MAO inhibitors are clinically available, they are associated with side effects such as hepatotoxicity, cheese reaction, hypertensive crisis, and so on, necessitating the investigation of alternative MAO inhibitors from a natural source with a safe profile. Herbal medications have a significant impact on the prevention of many diseases; additionally, they have fewer side effects and serve as a precursor for drug development. This review discusses the potential of herbal MAO inhibitors as well as their associated mechanism of action, with an aim to foster future research on herbal MAO inhibitors as a potential treatment for neurological diseases.

Key Engineering Materials, 2020

In this research, mild steel weldments are tested by varying nickel content into the weld beads. ... more In this research, mild steel weldments are tested by varying nickel content into the weld beads. Three mild steel plates have been joined using three electrodes with similar chemical composition except nickel content 0%, 9-11% and 19-21% respectively, by SMAW process and keeping heat input constant at all. The performance of welded specimens was evaluated by Charpy V-notch impact tests under different temperature conditions (25°C, 0°C, -20°C, -40°C, -60°C). It was found that the weldment with 0% nickel content is suffering rapid transition from ductile to brittle at-60°C, thus toughness reduces to approximately 1/5th of its value at room temperature. Microstructure revealed that at inter-dendritic regions mainly martensite was found. In dendrite core regions of the low carbon weld metals, a mixture of upper bainite, lower bainite and a novel constituent coalesced bainite formed. The fractured surface pattern was also observed using SEM, to reveal the ratio of area underwent ductile ...

Journal of the Indian Institute of Science, 2019

Introduction Condensation of vapor plays a crucial role in a wide range of large-scale energy sys... more Introduction Condensation of vapor plays a crucial role in a wide range of large-scale energy systems. In particular, steam power plants and HVAC systems, which, respectively, account for 78% of global electric power generation 1, 2 and 10-20% of total energy consumption in developed countries 3 , rely on the process of vapor condensation. Besides steam power plants and HVAC systems, efficiency of several industrial applications such as water desalination 4-7 , water collection 8-10 and thermal management 11-13 depend on vapor condensation. Therefore, any improvement in the efficiency of vapor condensation process can lead to significant energy savings. Condensation can be categorized as either filmwise condensation (FWC) or dropwise condensation (DWC). Figure 1 shows the schematic and Fig. 2 shows the images illustrating FWC and DWC. In FWC, the condensate forms a liquid film on the surface. This liquid film provides additional thermal resistance to heat transfer between the surface and the vapor. On the other hand, in DWC, vapor forms distinct liquid drops

Journal of neurosciences in rural practice, 2017

Nerve conduction studies (NCSs) are essential for diagnosing various kinds of focal and diffuse n... more Nerve conduction studies (NCSs) are essential for diagnosing various kinds of focal and diffuse neuropathies. Due to the paucity of local NCS data, electrodiagnostic laboratories in Punjab rely on values from Western and other Indian studies. This study was conducted to provide normative data for median nerve conduction parameters (motor and sensory) in Punjabi populace. A cross-sectional study was done on 290 participants (150 males and 140 females), aged 17-21 years, as per standardized protocol. The data were analyzed separately for both genders using SPSS version 20. It consisted of distal latencies and conduction velocities of motor and sensory divisions of median nerve. Student's unpaired t-test was used for statistical analysis. There was no effect of gender on any of the median nerve conduction parameters. Height and weight had nonsignificant negative and positive correlation, respectively (P > 0.05), with conduction velocity in both motor and sensory median nerves. F...

International Journal of Otorhinolaryngology and Head and Neck Surgery, 2017

Allergic rhinitis is an immunoglobulin E-mediated disease, thought to occur after exposure to ind... more Allergic rhinitis is an immunoglobulin E-mediated disease, thought to occur after exposure to indoor and outdoor allergens such as dust mites, insects, animal danders, molds and pollens. Symptoms include rhinorrhea, nasal congestion, obstruction, and pruritus. 1 It is associated with sleep disturbances, daytime somnolence, and fatigue. The exact relationship between rhinitis and sleep disturbance is unknown; however, both ABSTRACT Background: Allergic rhinitis is associated with sleep disturbances, daytime somnolence, and fatigue. Hence, present study was undertaken to evaluate and compare the nocturnal symptoms such difficulty in going to sleep, night time awakening and nasal congestion/obstruction on awakening among allergic rhinitis patients after administration of montelukast, chlorpheniramine meleate, levocetrizine, desloratidine and fexofenadine and to find out anti-allergic drug with maximum improvement in total symptom complex score. Methods: The present study comprised of 125 patients suffering from allergic rhinitis on the basis of characteristic history, corroborative physical findings and blood eosinophilia. Night times symptoms including difficulty in going to sleep, night time awakenings and nasal congestion on awakening were evaluated after patients were given oral treatment with chlorpheniramine maleate, levocetrizine, fexofenadine, desloratadine and montelukast for a period of 6 weeks in different 5 groups and the result interpreted on the basis of symptoms relieved. Symptoms were recorded on day 1, 2 weeks, 4 weeks and 6 weeks of treatment and analysed. All the patients were randomly divided into five groups of 25 each. The results were tabulated and analyzed by chi-square, Kruskal-Wallis test. Results: The present study found that levocetirizine provided immediate effect at 2 weeks which is significantly better than other drugs. But at 6 weeks, montelukast is best among the drugs which were compared; followed by levocetrizine, fexofenadine, and desloratadine and chlorpheniramine maleate. Montelukast was found to be a better drug as it has no significant side effects. Desloratadine group had dryness of mouth. Chlorpheniramine maleate has maximum side effects. 6 patients who took chlorpheniramine maleate complained of sedation, 1 patient complain of psychomotor disturbance. Conclusions: The present study concludes that in terms of clinical efficacy, safety/tolerability and improvement in night time symptom scores at six weeks therapy in allergic rhinitis, montelukast is the better drug.

European journal of pharmacology, 2016

The present study investigated the infiltration of mast cells into the kidney tissue and the prev... more The present study investigated the infiltration of mast cells into the kidney tissue and the preventive role of mast cell stabilizers against high fat diet (HFD)-induced renal injury in rats. The animals were fed on HFD (30% fat) for 12 consecutive weeks to induce renal injury. The HFD-induced obesity was assessed by calculating obesity index, adiposity index, and estimation of total cholesterol, triglycerides, and high density lipoproteins in plasma. The renal dysfunction was evaluated by measuring creatinine clearance, blood urea nitrogen, uric acid, electrolytes and microproteinuria. The oxidative stress in renal tissues was determined by myeloperoxidase activity, thiobarbituric acid reactive substances, superoxide anion generation and reduced glutathione level. The systolic blood pressure (SBP) was monitored using non-invasive blood pressure measuring apparatus. Histamine and hydroxyproline contents were quantified in renal tissues. Gross histopathological changes, mast cell den...

Biomass and Bioenergy, 2015

To increase microalgae biomass production and support high density cultures in photobioreactors a... more To increase microalgae biomass production and support high density cultures in photobioreactors artificial illumination systems have been designed to increase photosynthetic activity. Supplemental lighting systems are commonly composed by a combination of chlorophyll (a + b) strongly absorbed wavelengths, while weakly absorbed wavelengths are not present. At this work we compared the photosynthetic activity and biomass production induced by chlorophyll (a + b) strongly versus weakly absorbed wavelengths in Scenedesmus bijuga microalgae cultures at different biomass densities. Photosynthetic activity and biomass production induced by 4 different wavelengths using LEDs (blue-peak at λ470 nm; green-peak at λ530 nm; red-peak at λ655 nm; and white-4100 K) were measured and analyzed on high-density cultures of Scenedesmus bijuga. As culture density increased the chlorophyll (a + b) weakly absorbed green light penetrated deeper into the samples inducing higher oxygen evolution at culture concentration of 1.45 g L-1 compared to the chlorophyll (a + b) strongly absorbed red light. High-density culture (2.19 g L-1) cultivated under green light showed higher biomass production rate (30 mg L-1 d-1) with a 8.43% biomass growth in a 6-day period compared to the same quantum flux of red light that induced 4.35% biomass growth on the same period. The integration of green LEDs into photobioreactors lighting apparatus could improve the existing systems composed predominantly by red and blue LEDs increasing biomass productivity of high-density cultures at latter stages of microalgae cultivation.

49th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition, 2011

The use of flatback airfoils has been proposed for the inboard portion of horizontal axis wind tu... more The use of flatback airfoils has been proposed for the inboard portion of horizontal axis wind turbine blades. The advantages of this blade geometry include a lighter, stronger blade with reduced sensitivity to soiling that is easier to transport. The DU97-W-300 and its 10% thick trailing edge flatback counterpart have been tested in a University of Wyoming wind tunnel in both static and dynamically pitching configurations because real wind turbine blades experience similar dynamic pitching due to yaw effects and shear in the inflow. Surface pressure and particle image velocimetry data have been collected at a Reynolds number of 121,000. The results show that the flatback does exhibit advantageous aerodynamic characteristics in both the static and dynamic configurations. Fundamental vortex shedding from the blunt trailing edge is present in both the static and dynamic cases, but in the more realistic dynamic case the flow is dominated by the effects of the dynamic pitching of the airfoil. This dynamic behavior has a severe impact on the aerodynamic characteristics of the blade. Better wind turbine blade designs would result from a more complete understanding of such realistic flow characteristics.

Algal Biorefineries, 2013

ABSTRACT Microalgae are aquatic microorganisms growing phototrophically using sunlight and inorga... more ABSTRACT Microalgae are aquatic microorganisms growing phototrophically using sunlight and inorganic nutrients viz. carbon, nitrogen, phosphorus and other micronutrients. Sustainable production of microalgae biomass as feedstock for renewable biofuels is facing important bottlenecks in nutrient and water requirements that may hinder commercial scale development of algal systems. Fertilizer nutrients and fresh water contribute up to 50% of the total biomass production cost that eventually impact the economical feasibility of algal fuels. In the algae-biofuels industry, nutrients must be found in lower-value sources like wastewaters and other waste streams and for sustainable production, those nutrients be recycled within the system. Integration of algal wastewater treatment with biofuel production has been strongly promoted recently. Utilizing nutrient rich wastewaters and animal wastes like poultry litter can greatly reduce the water and fertilizer demands for algaculture. Additionally, producing algal feedstock from low-cost waste based nutrient media has multiple benefits including improved water quality, N and P recycling from animal waste, reduced environmental footprints, and economic efficiency. This approach appears very attractive, since the impacts of releasing N and P and greenhouse gases into the environment could be mitigated, while conserving nutrients and simultaneously producing a material that can replace crude oil as a fuel feedstock.

Biotechnological Applications of Microalgae, 2013

50th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition, 2012

Post processing techniques for aerodynamic data acquired from a Siemens' SWT-2.3 101 turbine have... more Post processing techniques for aerodynamic data acquired from a Siemens' SWT-2.3 101 turbine have been developed and applied in this paper. The turbine is installed at the National Wind Technology Center (NWTC) as part of Cooperative Research and De velopment Agreement between Siemens Wind Power and the National Renewable Energy Laboratory (NREL) under U.S. Department of Energy (DOE) sponsorship. The results indicate that the use of these corrections is essential for accurate analysis of the data. An example of local inflow angles, velocities, and inflow velocity over the rotor plane derived from measurements from a 5-hole probe is also presented. Finally, the pressure measure ments are used to characterize unsteady phenomenon, namely, rotational augmentation and dynamic stall on an inboard station. The results show that the rotational augmentation can considerably increase the attached flow regime compared to the 2D Computational Fluid Dynamics (CFD) results. The dynamic stall event was seen to significantly delay the stall. Furthermore, the non-dimensionalized vortex convection derived from the dynamic stall event was found to agree well with results from others studies.

Microbial biotechnology: energy and environment

This paper discusses the utilization of algal fuel cells and biohydrogen, and the latest developm... more This paper discusses the utilization of algal fuel cells and biohydrogen, and the latest developments in the field of microbe utilization for the production of bioenergy.

49th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition, 2011

An experiment has been performed to characterize the flow over a two-dimensional, pitching blade ... more An experiment has been performed to characterize the flow over a two-dimensional, pitching blade section by taking surface pressure measurements as well as flow-field measurements using PIV. This investigation was conducted in order to determine the effect of the dynamic motion associated with wind turbine blades on the flow field. Surface pressure and flow-field PIV measurements were taken with the blade set at fixed angles of attack as well as in dynamic motion through an angle of attack range of-3 • to 17 • at reduced frequencies, k, of 0.07 and 0.15. The results indicate that flow associated with the dynamic blade section varies greatly in comparison with the flow of the static blade over most of the angle of attack range. It became clear during this study that both surface and flow-field data are required to determine what is happening in these complex flows.

Color constancy is the capability to determine colors of objects independent of the color of the ... more Color constancy is the capability to determine colors of objects independent of the color of the light source. This paper deals with the different color constancy algorithms to evaluate the performance of existing color constancy algorithms. The combined effect of two color constancy algorithms i.e. White Patch Retinex (WPR) and Gray World (GW) and gamma correction used for dynamic range correction for image enhancement. The main limitation of the color constancy integrated with gamma correction proves to be efficient for dark regions but produce poor results for brighter regions. To reduce this problem in this paper we have proposed a new algorithm which will integrate the color constancy with histogram stretching and average filter to provide accurate results in dark, medium and brighter regions. The proposed algorithm is designed and implemented in MATLAB using image processing toolbox. The proposed algorithm provides significant as it has shown significantly better results in po...

space optics provides high data rate by allowing transmission of signal through atmosphere. The f... more space optics provides high data rate by allowing transmission of signal through atmosphere. The free space optics is also effected by different weather conditions. The atmospheric attenuation is caused by two main factors i.e. Absorption and Scattering. Fog, rain, snow and cloud causes the scattering of optical signals transmitted in free space. Fog is the most critical attenuating factor. The Snow Attenuation is also more severe than the Rain Attenuation due to large droplet size of snow. The hybrid FSO/RF system is considered for providing high availability. Frequencies in GHz range can improve the availability and it is selected as a back-up link. In this paper the effect of fog and snow on the performance of FSO and RF system is evaluated.

This paper presents a review on different color constancy techniques. Color constancy is the capa... more This paper presents a review on different color constancy techniques. Color constancy is the capability to determine colors of objects independent of the color of the light source. This work deal with different color constancy algorithms to evaluate the performance of existing color constancy algorithms. Different research papers are evaluated in this paper and it is found that most of existing algorithm work fine and provide efficient results. It is found that the every color constancy algorithm if follow by the gamma correction is proved to be quite efficient than available algorithms.

International Journal of Adhesion and Adhesives, 2021

Chemical Engineering Journal, 2021

Current Drug Targets, 2022

: Monoamine oxidase (MAO) is an enzyme that catalyzes the deamination of monoamines and other pro... more : Monoamine oxidase (MAO) is an enzyme that catalyzes the deamination of monoamines and other proteins. MAO’s hyperactivation results in the massive generation of reactive oxygen species, which leads to a variety of neurological diseases such as Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, Huntington's disease, and depression-like disorders. Although synthetic MAO inhibitors are clinically available, they are associated with side effects such as hepatotoxicity, cheese reaction, hypertensive crisis, and so on, necessitating the investigation of alternative MAO inhibitors from a natural source with a safe profile. Herbal medications have a significant impact on the prevention of many diseases; additionally, they have fewer side effects and serve as a precursor for drug development. This review discusses the potential of herbal MAO inhibitors as well as their associated mechanism of action, with an aim to foster future research on herbal MAO inhibitors as a potential treatment for neurological diseases.

Key Engineering Materials, 2020

In this research, mild steel weldments are tested by varying nickel content into the weld beads. ... more In this research, mild steel weldments are tested by varying nickel content into the weld beads. Three mild steel plates have been joined using three electrodes with similar chemical composition except nickel content 0%, 9-11% and 19-21% respectively, by SMAW process and keeping heat input constant at all. The performance of welded specimens was evaluated by Charpy V-notch impact tests under different temperature conditions (25°C, 0°C, -20°C, -40°C, -60°C). It was found that the weldment with 0% nickel content is suffering rapid transition from ductile to brittle at-60°C, thus toughness reduces to approximately 1/5th of its value at room temperature. Microstructure revealed that at inter-dendritic regions mainly martensite was found. In dendrite core regions of the low carbon weld metals, a mixture of upper bainite, lower bainite and a novel constituent coalesced bainite formed. The fractured surface pattern was also observed using SEM, to reveal the ratio of area underwent ductile ...

Journal of the Indian Institute of Science, 2019

Introduction Condensation of vapor plays a crucial role in a wide range of large-scale energy sys... more Introduction Condensation of vapor plays a crucial role in a wide range of large-scale energy systems. In particular, steam power plants and HVAC systems, which, respectively, account for 78% of global electric power generation 1, 2 and 10-20% of total energy consumption in developed countries 3 , rely on the process of vapor condensation. Besides steam power plants and HVAC systems, efficiency of several industrial applications such as water desalination 4-7 , water collection 8-10 and thermal management 11-13 depend on vapor condensation. Therefore, any improvement in the efficiency of vapor condensation process can lead to significant energy savings. Condensation can be categorized as either filmwise condensation (FWC) or dropwise condensation (DWC). Figure 1 shows the schematic and Fig. 2 shows the images illustrating FWC and DWC. In FWC, the condensate forms a liquid film on the surface. This liquid film provides additional thermal resistance to heat transfer between the surface and the vapor. On the other hand, in DWC, vapor forms distinct liquid drops

Journal of neurosciences in rural practice, 2017

Nerve conduction studies (NCSs) are essential for diagnosing various kinds of focal and diffuse n... more Nerve conduction studies (NCSs) are essential for diagnosing various kinds of focal and diffuse neuropathies. Due to the paucity of local NCS data, electrodiagnostic laboratories in Punjab rely on values from Western and other Indian studies. This study was conducted to provide normative data for median nerve conduction parameters (motor and sensory) in Punjabi populace. A cross-sectional study was done on 290 participants (150 males and 140 females), aged 17-21 years, as per standardized protocol. The data were analyzed separately for both genders using SPSS version 20. It consisted of distal latencies and conduction velocities of motor and sensory divisions of median nerve. Student's unpaired t-test was used for statistical analysis. There was no effect of gender on any of the median nerve conduction parameters. Height and weight had nonsignificant negative and positive correlation, respectively (P > 0.05), with conduction velocity in both motor and sensory median nerves. F...

International Journal of Otorhinolaryngology and Head and Neck Surgery, 2017

Allergic rhinitis is an immunoglobulin E-mediated disease, thought to occur after exposure to ind... more Allergic rhinitis is an immunoglobulin E-mediated disease, thought to occur after exposure to indoor and outdoor allergens such as dust mites, insects, animal danders, molds and pollens. Symptoms include rhinorrhea, nasal congestion, obstruction, and pruritus. 1 It is associated with sleep disturbances, daytime somnolence, and fatigue. The exact relationship between rhinitis and sleep disturbance is unknown; however, both ABSTRACT Background: Allergic rhinitis is associated with sleep disturbances, daytime somnolence, and fatigue. Hence, present study was undertaken to evaluate and compare the nocturnal symptoms such difficulty in going to sleep, night time awakening and nasal congestion/obstruction on awakening among allergic rhinitis patients after administration of montelukast, chlorpheniramine meleate, levocetrizine, desloratidine and fexofenadine and to find out anti-allergic drug with maximum improvement in total symptom complex score. Methods: The present study comprised of 125 patients suffering from allergic rhinitis on the basis of characteristic history, corroborative physical findings and blood eosinophilia. Night times symptoms including difficulty in going to sleep, night time awakenings and nasal congestion on awakening were evaluated after patients were given oral treatment with chlorpheniramine maleate, levocetrizine, fexofenadine, desloratadine and montelukast for a period of 6 weeks in different 5 groups and the result interpreted on the basis of symptoms relieved. Symptoms were recorded on day 1, 2 weeks, 4 weeks and 6 weeks of treatment and analysed. All the patients were randomly divided into five groups of 25 each. The results were tabulated and analyzed by chi-square, Kruskal-Wallis test. Results: The present study found that levocetirizine provided immediate effect at 2 weeks which is significantly better than other drugs. But at 6 weeks, montelukast is best among the drugs which were compared; followed by levocetrizine, fexofenadine, and desloratadine and chlorpheniramine maleate. Montelukast was found to be a better drug as it has no significant side effects. Desloratadine group had dryness of mouth. Chlorpheniramine maleate has maximum side effects. 6 patients who took chlorpheniramine maleate complained of sedation, 1 patient complain of psychomotor disturbance. Conclusions: The present study concludes that in terms of clinical efficacy, safety/tolerability and improvement in night time symptom scores at six weeks therapy in allergic rhinitis, montelukast is the better drug.

European journal of pharmacology, 2016

The present study investigated the infiltration of mast cells into the kidney tissue and the prev... more The present study investigated the infiltration of mast cells into the kidney tissue and the preventive role of mast cell stabilizers against high fat diet (HFD)-induced renal injury in rats. The animals were fed on HFD (30% fat) for 12 consecutive weeks to induce renal injury. The HFD-induced obesity was assessed by calculating obesity index, adiposity index, and estimation of total cholesterol, triglycerides, and high density lipoproteins in plasma. The renal dysfunction was evaluated by measuring creatinine clearance, blood urea nitrogen, uric acid, electrolytes and microproteinuria. The oxidative stress in renal tissues was determined by myeloperoxidase activity, thiobarbituric acid reactive substances, superoxide anion generation and reduced glutathione level. The systolic blood pressure (SBP) was monitored using non-invasive blood pressure measuring apparatus. Histamine and hydroxyproline contents were quantified in renal tissues. Gross histopathological changes, mast cell den...

Biomass and Bioenergy, 2015

To increase microalgae biomass production and support high density cultures in photobioreactors a... more To increase microalgae biomass production and support high density cultures in photobioreactors artificial illumination systems have been designed to increase photosynthetic activity. Supplemental lighting systems are commonly composed by a combination of chlorophyll (a + b) strongly absorbed wavelengths, while weakly absorbed wavelengths are not present. At this work we compared the photosynthetic activity and biomass production induced by chlorophyll (a + b) strongly versus weakly absorbed wavelengths in Scenedesmus bijuga microalgae cultures at different biomass densities. Photosynthetic activity and biomass production induced by 4 different wavelengths using LEDs (blue-peak at λ470 nm; green-peak at λ530 nm; red-peak at λ655 nm; and white-4100 K) were measured and analyzed on high-density cultures of Scenedesmus bijuga. As culture density increased the chlorophyll (a + b) weakly absorbed green light penetrated deeper into the samples inducing higher oxygen evolution at culture concentration of 1.45 g L-1 compared to the chlorophyll (a + b) strongly absorbed red light. High-density culture (2.19 g L-1) cultivated under green light showed higher biomass production rate (30 mg L-1 d-1) with a 8.43% biomass growth in a 6-day period compared to the same quantum flux of red light that induced 4.35% biomass growth on the same period. The integration of green LEDs into photobioreactors lighting apparatus could improve the existing systems composed predominantly by red and blue LEDs increasing biomass productivity of high-density cultures at latter stages of microalgae cultivation.

49th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition, 2011

The use of flatback airfoils has been proposed for the inboard portion of horizontal axis wind tu... more The use of flatback airfoils has been proposed for the inboard portion of horizontal axis wind turbine blades. The advantages of this blade geometry include a lighter, stronger blade with reduced sensitivity to soiling that is easier to transport. The DU97-W-300 and its 10% thick trailing edge flatback counterpart have been tested in a University of Wyoming wind tunnel in both static and dynamically pitching configurations because real wind turbine blades experience similar dynamic pitching due to yaw effects and shear in the inflow. Surface pressure and particle image velocimetry data have been collected at a Reynolds number of 121,000. The results show that the flatback does exhibit advantageous aerodynamic characteristics in both the static and dynamic configurations. Fundamental vortex shedding from the blunt trailing edge is present in both the static and dynamic cases, but in the more realistic dynamic case the flow is dominated by the effects of the dynamic pitching of the airfoil. This dynamic behavior has a severe impact on the aerodynamic characteristics of the blade. Better wind turbine blade designs would result from a more complete understanding of such realistic flow characteristics.

Algal Biorefineries, 2013

ABSTRACT Microalgae are aquatic microorganisms growing phototrophically using sunlight and inorga... more ABSTRACT Microalgae are aquatic microorganisms growing phototrophically using sunlight and inorganic nutrients viz. carbon, nitrogen, phosphorus and other micronutrients. Sustainable production of microalgae biomass as feedstock for renewable biofuels is facing important bottlenecks in nutrient and water requirements that may hinder commercial scale development of algal systems. Fertilizer nutrients and fresh water contribute up to 50% of the total biomass production cost that eventually impact the economical feasibility of algal fuels. In the algae-biofuels industry, nutrients must be found in lower-value sources like wastewaters and other waste streams and for sustainable production, those nutrients be recycled within the system. Integration of algal wastewater treatment with biofuel production has been strongly promoted recently. Utilizing nutrient rich wastewaters and animal wastes like poultry litter can greatly reduce the water and fertilizer demands for algaculture. Additionally, producing algal feedstock from low-cost waste based nutrient media has multiple benefits including improved water quality, N and P recycling from animal waste, reduced environmental footprints, and economic efficiency. This approach appears very attractive, since the impacts of releasing N and P and greenhouse gases into the environment could be mitigated, while conserving nutrients and simultaneously producing a material that can replace crude oil as a fuel feedstock.

Biotechnological Applications of Microalgae, 2013

50th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition, 2012

Post processing techniques for aerodynamic data acquired from a Siemens' SWT-2.3 101 turbine have... more Post processing techniques for aerodynamic data acquired from a Siemens' SWT-2.3 101 turbine have been developed and applied in this paper. The turbine is installed at the National Wind Technology Center (NWTC) as part of Cooperative Research and De velopment Agreement between Siemens Wind Power and the National Renewable Energy Laboratory (NREL) under U.S. Department of Energy (DOE) sponsorship. The results indicate that the use of these corrections is essential for accurate analysis of the data. An example of local inflow angles, velocities, and inflow velocity over the rotor plane derived from measurements from a 5-hole probe is also presented. Finally, the pressure measure ments are used to characterize unsteady phenomenon, namely, rotational augmentation and dynamic stall on an inboard station. The results show that the rotational augmentation can considerably increase the attached flow regime compared to the 2D Computational Fluid Dynamics (CFD) results. The dynamic stall event was seen to significantly delay the stall. Furthermore, the non-dimensionalized vortex convection derived from the dynamic stall event was found to agree well with results from others studies.

Microbial biotechnology: energy and environment

This paper discusses the utilization of algal fuel cells and biohydrogen, and the latest developm... more This paper discusses the utilization of algal fuel cells and biohydrogen, and the latest developments in the field of microbe utilization for the production of bioenergy.

49th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition, 2011

An experiment has been performed to characterize the flow over a two-dimensional, pitching blade ... more An experiment has been performed to characterize the flow over a two-dimensional, pitching blade section by taking surface pressure measurements as well as flow-field measurements using PIV. This investigation was conducted in order to determine the effect of the dynamic motion associated with wind turbine blades on the flow field. Surface pressure and flow-field PIV measurements were taken with the blade set at fixed angles of attack as well as in dynamic motion through an angle of attack range of-3 • to 17 • at reduced frequencies, k, of 0.07 and 0.15. The results indicate that flow associated with the dynamic blade section varies greatly in comparison with the flow of the static blade over most of the angle of attack range. It became clear during this study that both surface and flow-field data are required to determine what is happening in these complex flows.