jameel ahmad - Academia.edu (original) (raw)

Papers by jameel ahmad

Research paper thumbnail of Distributed Control and Power Management of Islanded DC Nanogrids with Applications to Rural Electrification

2020 IEEE Energy Conversion Congress and Exposition (ECCE), 2020

DC Nanogrids (NGs) with integrated distributed generation are becoming more and more popular for ... more DC Nanogrids (NGs) with integrated distributed generation are becoming more and more popular for electrification of remote/rural communities. Stable as well as interactive operation of these NGs face many challenges such as optimal resource sharing among NGs. distribution losses and load/generation side transient control. etc. There are multiple communication-less control techniques that are insufficient to address these challenges. In this paper. we present a multi-agent communication based distributed control strategy that provides optimal resource sharing among NGs with minimized distribution losses and an improved transient control by employing augmented Lagrangian based optimized controller. The efficiency of proposed model is validated for various case study scenarios.

Research paper thumbnail of Distributed Control and Dynamic Optimization of a Microgrid

2020 IEEE Energy Conversion Congress and Exposition (ECCE), 2020

In this paper dynamics of a power system consisting of distributed generators in a microgrid is m... more In this paper dynamics of a power system consisting of distributed generators in a microgrid is modeled as a nonlinear system. The specific objectives are to optimize non-liner economic-emission dispatch and control the dynamics of power sharing of distributed generators in a microgrid. For efficient coordination of distributed generators, a multi-agent system with shared communication framework employing self-triggered data sampler is proposed. The system is tested for load as well as source side transients. The performance evaluation results show that distributed optimized control with proposed self-triggered strategy significantly reduces the bandwidth requirement. Numerical results show that approximately thirty-six times less data transmission is required during steady state while data transmission requirement during transients reduces twenty times, leading to significant reduction in the demanded communication bandwidth.

Research paper thumbnail of The use of testa of groundnut shell (Arachis hypogea) for the adsorption of Ni(II) from the aqueous system

Journal of environmental science & engineering, 2006

This paper presents the use of testa of groundnut shell for the removal of nickel from dilute aqu... more This paper presents the use of testa of groundnut shell for the removal of nickel from dilute aqueous solutions at laboratory scale. The adsorption isotherm of Ni(II) on the testa of groundnut shell was carried out by the batch adsorption process. Various parameters such as initial concentration, pH and amount of the adsorbent doses were studied. The experimental adsorption data obtained followed both Langmuir as well as Freundlich isotherms. Maximum adsorption (85%) was observed at pH 6. The monolayer adsorption capacity was found to be 18.79 mg/g, which is greater than most of the low-cost adsorbents reported.

Research paper thumbnail of Dynamic post-buckling characteristics of circular plates

Journal of the Franklin Institute, 1970

An approximate analytic method is developed herein to study the post-buckling response of a thin ... more An approximate analytic method is developed herein to study the post-buckling response of a thin elastic circular plate under the action of axisymmetric, time-dependent radial thrusts. The plate reaponae is assumed to be in resonance with th principal mode of vibration of the plate, thereby neglecting effects associated with higher vibrational modes. It is shown that for certain simple cases of loading history and for small penetrations of the post-buckling domain, the above assumption is a valid wpproximution and leads to a powerful simpli&ation in the governing equations of the problem which then reduce to a Sin&? nonlinear differential equation of the cubic order. It is the purpose of this paper to formulate this equation for which an analytical solution is then obtained. The post-buckling response of the plate under a step loading history is presented.

Research paper thumbnail of Chromatography of Anions on Alumina Thin Layers: Effect of Transition Metals on CI--Br--I- and No-2-NO-3 Separations

Journal of Liquid Chromatography & Related Technologies, 1991

Abstract Chromatographic behaviour of eighteen anions on thin layers of alumina and alumina mixed... more Abstract Chromatographic behaviour of eighteen anions on thin layers of alumina and alumina mixed with silica gel (1: 1, 1: 2 and 2: 1) has been studied using mixed acidic organic solvent systems containing formic acid. Though the addition of silica gel to ...

Research paper thumbnail of SARS‐CoV‐2 infection and venous thromboembolism after surgery: an international prospective cohort study

Anaesthesia, 2021

SummarySARS‐CoV‐2 has been associated with an increased rate of venous thromboembolism in critica... more SummarySARS‐CoV‐2 has been associated with an increased rate of venous thromboembolism in critically ill patients. Since surgical patients are already at higher risk of venous thromboembolism than general populations, this study aimed to determine if patients with peri‐operative or prior SARS‐CoV‐2 were at further increased risk of venous thromboembolism. We conducted a planned sub‐study and analysis from an international, multicentre, prospective cohort study of elective and emergency patients undergoing surgery during October 2020. Patients from all surgical specialties were included. The primary outcome measure was venous thromboembolism (pulmonary embolism or deep vein thrombosis) within 30 days of surgery. SARS‐CoV‐2 diagnosis was defined as peri‐operative (7 days before to 30 days after surgery); recent (1–6 weeks before surgery); previous (≥7 weeks before surgery); or none. Information on prophylaxis regimens or pre‐operative anti‐coagulation for baseline comorbidities was no...

Research paper thumbnail of Distributed Control and Power Management of Islanded DC Nanogrids with Applications to Rural Electrification

2020 IEEE Energy Conversion Congress and Exposition (ECCE), 2020

DC Nanogrids (NGs) with integrated distributed generation are becoming more and more popular for ... more DC Nanogrids (NGs) with integrated distributed generation are becoming more and more popular for electrification of remote/rural communities. Stable as well as interactive operation of these NGs face many challenges such as optimal resource sharing among NGs. distribution losses and load/generation side transient control. etc. There are multiple communication-less control techniques that are insufficient to address these challenges. In this paper. we present a multi-agent communication based distributed control strategy that provides optimal resource sharing among NGs with minimized distribution losses and an improved transient control by employing augmented Lagrangian based optimized controller. The efficiency of proposed model is validated for various case study scenarios.

Research paper thumbnail of Distributed Control and Dynamic Optimization of a Microgrid

2020 IEEE Energy Conversion Congress and Exposition (ECCE), 2020

In this paper dynamics of a power system consisting of distributed generators in a microgrid is m... more In this paper dynamics of a power system consisting of distributed generators in a microgrid is modeled as a nonlinear system. The specific objectives are to optimize non-liner economic-emission dispatch and control the dynamics of power sharing of distributed generators in a microgrid. For efficient coordination of distributed generators, a multi-agent system with shared communication framework employing self-triggered data sampler is proposed. The system is tested for load as well as source side transients. The performance evaluation results show that distributed optimized control with proposed self-triggered strategy significantly reduces the bandwidth requirement. Numerical results show that approximately thirty-six times less data transmission is required during steady state while data transmission requirement during transients reduces twenty times, leading to significant reduction in the demanded communication bandwidth.

Research paper thumbnail of The use of testa of groundnut shell (Arachis hypogea) for the adsorption of Ni(II) from the aqueous system

Journal of environmental science & engineering, 2006

This paper presents the use of testa of groundnut shell for the removal of nickel from dilute aqu... more This paper presents the use of testa of groundnut shell for the removal of nickel from dilute aqueous solutions at laboratory scale. The adsorption isotherm of Ni(II) on the testa of groundnut shell was carried out by the batch adsorption process. Various parameters such as initial concentration, pH and amount of the adsorbent doses were studied. The experimental adsorption data obtained followed both Langmuir as well as Freundlich isotherms. Maximum adsorption (85%) was observed at pH 6. The monolayer adsorption capacity was found to be 18.79 mg/g, which is greater than most of the low-cost adsorbents reported.

Research paper thumbnail of Dynamic post-buckling characteristics of circular plates

Journal of the Franklin Institute, 1970

An approximate analytic method is developed herein to study the post-buckling response of a thin ... more An approximate analytic method is developed herein to study the post-buckling response of a thin elastic circular plate under the action of axisymmetric, time-dependent radial thrusts. The plate reaponae is assumed to be in resonance with th principal mode of vibration of the plate, thereby neglecting effects associated with higher vibrational modes. It is shown that for certain simple cases of loading history and for small penetrations of the post-buckling domain, the above assumption is a valid wpproximution and leads to a powerful simpli&ation in the governing equations of the problem which then reduce to a Sin&? nonlinear differential equation of the cubic order. It is the purpose of this paper to formulate this equation for which an analytical solution is then obtained. The post-buckling response of the plate under a step loading history is presented.

Research paper thumbnail of Chromatography of Anions on Alumina Thin Layers: Effect of Transition Metals on CI--Br--I- and No-2-NO-3 Separations

Journal of Liquid Chromatography & Related Technologies, 1991

Abstract Chromatographic behaviour of eighteen anions on thin layers of alumina and alumina mixed... more Abstract Chromatographic behaviour of eighteen anions on thin layers of alumina and alumina mixed with silica gel (1: 1, 1: 2 and 2: 1) has been studied using mixed acidic organic solvent systems containing formic acid. Though the addition of silica gel to ...

Research paper thumbnail of SARS‐CoV‐2 infection and venous thromboembolism after surgery: an international prospective cohort study

Anaesthesia, 2021

SummarySARS‐CoV‐2 has been associated with an increased rate of venous thromboembolism in critica... more SummarySARS‐CoV‐2 has been associated with an increased rate of venous thromboembolism in critically ill patients. Since surgical patients are already at higher risk of venous thromboembolism than general populations, this study aimed to determine if patients with peri‐operative or prior SARS‐CoV‐2 were at further increased risk of venous thromboembolism. We conducted a planned sub‐study and analysis from an international, multicentre, prospective cohort study of elective and emergency patients undergoing surgery during October 2020. Patients from all surgical specialties were included. The primary outcome measure was venous thromboembolism (pulmonary embolism or deep vein thrombosis) within 30 days of surgery. SARS‐CoV‐2 diagnosis was defined as peri‐operative (7 days before to 30 days after surgery); recent (1–6 weeks before surgery); previous (≥7 weeks before surgery); or none. Information on prophylaxis regimens or pre‐operative anti‐coagulation for baseline comorbidities was no...