Ahmed Shakeel - Academia.edu (original) (raw)

Papers by Ahmed Shakeel

Environmental Engineering Research

Monitoring a non-linear phenomenon-such as the groundwater levels in an aquifer-by cost-effective... more Monitoring a non-linear phenomenon-such as the groundwater levels in an aquifer-by cost-effective techniques is quite a difficult task. To overcome these limitations, soft computing tools are increasingly being used to predict groundwater levels with high accuracy. In the present study, a soft computing tool called support vector machine (SVM) was employed for predicting the groundwater levels jointly using weather parameters, at Maheshwaram watershed, Hyderabad, Andhra Pradesh, India. The accuracy of this approach was established based on statistical tools termed the regression coefficient, root mean square error, Nash-Sutcliffe coefficient, and error variation. For performance evaluation, the model outputs were compared with traditional statistical multiple regression (SMR) model outputs, and it was found that the SVR method offers better prediction than does SMR.

Day 3 Wed, February 23, 2022, 2022

Untreated disposal of effluent water has the potential of scaling and plugging the in and near-we... more Untreated disposal of effluent water has the potential of scaling and plugging the in and near-wellbore regions. A case study and methodology adopted for the clean-out operation of water disposal well of Khurmala Field of Iraq is analyzed in the paper. Previous attempts of clean-out using high-pressure hydro- jetting tools along with acid treatment proved futile effort. As last resort, Fluidic Oscillator (SFO) was deployed for clean-out to regain access of TD and plugged fracture network before the eventual decision of work-over is made. Combination of SFO having pulsing, cavitation, and helix jetting action in conjunction with train of fluids consisting of diesel, 28% HCl and gel were utilized. The operational sequence of clean-out was in stages of 10m to clean 79m interval, comprising of slotted liner and open hole, filled with detritus. Low bottom pressure required a dynamic approach for treatment-fluid nitrification based on the success of clean-out and access to liner and open ...

Day 3 Thu, September 23, 2021, 2021

A case study and methodology is presented to shed the light on the different processes followed d... more A case study and methodology is presented to shed the light on the different processes followed during the placement of a non-damaging isolation barrier in a group of highly naturally-fractured and vugular gas wells. The temporary isolation aims at isolating the wellbore from the troublesome formation and allow the removal of the original completion string and install a new redesigned one. The process helped putting the wells back on production with-out the need to stimulate any of them. This helped client to reduce the overall workover cost by 40% and proved to be successful and efficient to complete the required operation in a time-efficient. The operator had 4 wells with OH sections ranging from 40-80m which were completed in the late 1990's with no production packer. To preserve wellbore integrity the completion string needed to be pulled and replaced by a string with production packer and DH gauges. Visco-Elastic Surfactant (VES) and calcium CaCO3 (carbonate) used ubiquitou...

Frontiers in Engineering and Built Environment, 2021

PurposeDeepor Beel is one of the Ramsar Site and a wetland of great biodiversity, situated in the... more PurposeDeepor Beel is one of the Ramsar Site and a wetland of great biodiversity, situated in the south-western part of Guwahati, Assam. With urban development at its forefront city of Guwahati, Deepor Beel is under constant threat. The study aims to calculate the lake water volume from the water surface area and the underwater terrain data using a triangulated irregular network (TIN) volume model.Design/methodology/approachThe lake water surface boundaries for each year were combined with field-observed water level data to generate a description of the underwater terrain. Time series LANDSAT images of 2001, 2011 and 2019 were used to extract the modified normalized difference water index (MNDWI) in GIS domain.FindingsThe MNDWI was 0.462 in 2001 which reduced to 0.240 in 2019. This shows that the lake water storage capacity shrank in the last 2 decades. This leads to a major problem, i.e. the storage capacity of the lake has been declining gradually from 20.95 million m3 in 2001 to ...

Journal of Pediatric Ophthalmology & Strabismus, 2007

Necrotizing Pseudomonas Infection of the Ocular Adnexa in an Infant With Leukocyte Adhesion Defec... more Necrotizing Pseudomonas Infection of the Ocular Adnexa in an Infant With Leukocyte Adhesion Defect To the Editors:A 14-day-old male neonate presented with left congenital nasolacrimal duct obstruction and was prescribed topical antibiotics. One week later, he developed an ulcer over the medial canthus of the left eye. Cultures from the wound grew Pseudomonas aeruginosa. Intravenous amikacin and metronidazole were commenced. The ulcerative lesion progressively destroyed the medial upper and lower eyelids, medial canthus, and part of the left lacrimal drainage system, and extended through the maxillary antrum to cause a hard-palate perforation (Fig. 1). Intravenous meropenem was added, and topical gentamicin was increased to every 2 hours. Artificial tears and lid taping were advised. Complete blood count revealed leukocytosis. Flow cytometry analysis of the 2 integrin revealed absent surface membrane expression of CD18 on polymorphonuclear leukocytes, confirming the diagnosis of leuk...

Acta Carsologica, 2012

Indija: Posledice �a �aloge pod�emne vode Sedimentacijski bazen Cuddapah obsega pomemben del južn... more Indija: Posledice �a �aloge pod�emne vode Sedimentacijski bazen Cuddapah obsega pomemben del južnega dela indijske države Andhra Pradesh. Proterozojske karbonate sestavljajo tri glavne enote, Vempalle dolomit ter Narji in Koilkuntla apnenci. Ti karbonati so lokalno pomembni, saj predstavljajo glavni vodni vir za namakanje in gospodinjstva ter pomemben vir gradbenih materialov. Poznavanje stopnje zakraselosti karbonatov je lahko pomembno pri upravljanju vodnih virov in inženirskih posegih na območju. Terenske raziskave so pokazale veliko zakraselost omenjenih karbonatov; pomemben del napajanja vodonosnikov poteka točkovno, skozi ponore, pretakanje pa se vrši v dobro razviti mreži kraških kanalov. Glavna faza razvoja krasa je verjetno potekala v preteklih, bolj vlažnih obdobjih. Procesi zakrasevanja v današnji polsušni klimi so posebej intenzivni na območju, kjer se na kras steka voda iz kvarcitnega zaledja. Zakraselost karbonatov bo treba upoštevati pri upravljanju območja in bodočih razvojnih projektih. Le na ta način se bomo lahko izognili težavam, kot so puščanje iz jezov, udiranje, napačna ocena vodnih zalog in podobno. Ključne besede: kras, kraški vodonosnik, jama, polsušno, zaloga podzemne vode, Indija.

A mutant MS301 of Aspergillus niger MS82 showed 1.5 to 2.5-fold improved endoglucanase and β-gluc... more A mutant MS301 of Aspergillus niger MS82 showed 1.5 to 2.5-fold improved endoglucanase and β-glucosidase activity when grown on crude lignocellulosic substrates under solid-state and submerged conditions. Indicators of thermal stability of enzymes (T m and T 1/2) showed that the wild type and mutant endoglucanase was more heat-resistant compared to β-glucosidase. However, mutant and parent enzymes shared almost the same values for melting temperatures and half-lives. Endoglucanase and β-glucosidase from both the strains showed optimum activity under acidic pH. Energy of activation (Ea) of mutant β-glucosidase was substantially lower than the parent enzyme while E a of mutant endoglucanase was slightly less than the parent. The lowered E a values can be attributed to the improved β-glucosidase activity of the mutant strain. Moreover, the MS301 enzymes were better in hydrolyzing purified and crude cellulosic materials than the parent MS82. Introduction Lignocellulosic biomass constitu...

Day 3 Wed, October 30, 2013, 2013

Continuous well performance monitoring plays a key role in making decision related to well workov... more Continuous well performance monitoring plays a key role in making decision related to well workover and production optimization. Well parameters and corresponding rates over a period of time will represent the change in well performance. Live Well models are useful for estimating the continuous well production rates. Well models become live if they get updated with changing fluid and reservoir properties along with proper calibration to latest well conditions. In general industry practice is to update the model manually; this is a tidious and time consuming process. Umm Gudair Field Development team implemented a real time system using available resources that integrates and runs workflows between corporate data base, well surveillance data base and well models. Workflows were implemented as part of the real time system to calculate the well parameters from sensor readings and update the models to run on daily basis, such that the models become live and production rates will be esti...

International Journal of Distributed and Parallel systems, 2011

In mobile ad hoc networks, there is no centralized infrastructure to monitor or allocate the reso... more In mobile ad hoc networks, there is no centralized infrastructure to monitor or allocate the resources used by the mobile nodes. The absence of any central coordinator makes the routing a complex one compared to cellular networks. The Ad hoc On Demand Distance Vector (AODV) routing algorithm is a routing protocol designed for ad hoc mobile devices. AODV uses an on demand approach for finding routes. AODV and most of the on demand ad hoc routing protocols use single route reply along the reverse path. Due to rapid changes of topology the route reply may not arrive to the source node resulting in sending several route request messages and degrading the performance of the routing protocol. The extended AODV called Reverse Ad Hoc On Demand Vector (R-AODV) protocol uses a reverse route discovery mechanism and performs well when link breakage is frequent. In this paper we compare the QoS parameters such as Throughput, Delay and Packet Delivery ratio of both traditional AODV and R-AODV using TCP New Reno as the traffic source. Simulation results show that R-AODV performs well when link breakage is frequent.

Groundwater Dynamics in Hard Rock Aquifers

Hydrogeology Journal, 2014

ABSTRACT About 3 % of India’s total land surface is occupied by carbonate rocks which are mostly ... more ABSTRACT About 3 % of India’s total land surface is occupied by carbonate rocks which are mostly karstified and constitute a significant source of groundwater. The groundwater drawn from these aquifers matches the water demand of ~35 million people living in 106 districts of the country and also the water needs of livestock, irrigation and industry. The studies on karst in India carried out so far have mostly addressed geology, hydrology and groundwater contamination. A literature survey suggests that there is a need for detailed research, applying new approaches and techniques for proper carbonate aquifer identification, characterization and management. Such specific approaches will improve modeling, exploitation and protection of karst groundwater. An overview of the research carried out on groundwater resources of karst formations in India is presented, which also throws light on the protection of karst aquifers from existing anthropogenic activities such as mining and groundwater over-exploitation.

Groundwater Dynamics in Hard Rock Aquifers

Stochastic Environmental Research and Risk Assessment, 2006

Journal of the Geological Society of India, 2011

Environmental Engineering Research

Monitoring a non-linear phenomenon-such as the groundwater levels in an aquifer-by cost-effective... more Monitoring a non-linear phenomenon-such as the groundwater levels in an aquifer-by cost-effective techniques is quite a difficult task. To overcome these limitations, soft computing tools are increasingly being used to predict groundwater levels with high accuracy. In the present study, a soft computing tool called support vector machine (SVM) was employed for predicting the groundwater levels jointly using weather parameters, at Maheshwaram watershed, Hyderabad, Andhra Pradesh, India. The accuracy of this approach was established based on statistical tools termed the regression coefficient, root mean square error, Nash-Sutcliffe coefficient, and error variation. For performance evaluation, the model outputs were compared with traditional statistical multiple regression (SMR) model outputs, and it was found that the SVR method offers better prediction than does SMR.

Day 3 Wed, February 23, 2022, 2022

Untreated disposal of effluent water has the potential of scaling and plugging the in and near-we... more Untreated disposal of effluent water has the potential of scaling and plugging the in and near-wellbore regions. A case study and methodology adopted for the clean-out operation of water disposal well of Khurmala Field of Iraq is analyzed in the paper. Previous attempts of clean-out using high-pressure hydro- jetting tools along with acid treatment proved futile effort. As last resort, Fluidic Oscillator (SFO) was deployed for clean-out to regain access of TD and plugged fracture network before the eventual decision of work-over is made. Combination of SFO having pulsing, cavitation, and helix jetting action in conjunction with train of fluids consisting of diesel, 28% HCl and gel were utilized. The operational sequence of clean-out was in stages of 10m to clean 79m interval, comprising of slotted liner and open hole, filled with detritus. Low bottom pressure required a dynamic approach for treatment-fluid nitrification based on the success of clean-out and access to liner and open ...

Day 3 Thu, September 23, 2021, 2021

A case study and methodology is presented to shed the light on the different processes followed d... more A case study and methodology is presented to shed the light on the different processes followed during the placement of a non-damaging isolation barrier in a group of highly naturally-fractured and vugular gas wells. The temporary isolation aims at isolating the wellbore from the troublesome formation and allow the removal of the original completion string and install a new redesigned one. The process helped putting the wells back on production with-out the need to stimulate any of them. This helped client to reduce the overall workover cost by 40% and proved to be successful and efficient to complete the required operation in a time-efficient. The operator had 4 wells with OH sections ranging from 40-80m which were completed in the late 1990's with no production packer. To preserve wellbore integrity the completion string needed to be pulled and replaced by a string with production packer and DH gauges. Visco-Elastic Surfactant (VES) and calcium CaCO3 (carbonate) used ubiquitou...

Frontiers in Engineering and Built Environment, 2021

PurposeDeepor Beel is one of the Ramsar Site and a wetland of great biodiversity, situated in the... more PurposeDeepor Beel is one of the Ramsar Site and a wetland of great biodiversity, situated in the south-western part of Guwahati, Assam. With urban development at its forefront city of Guwahati, Deepor Beel is under constant threat. The study aims to calculate the lake water volume from the water surface area and the underwater terrain data using a triangulated irregular network (TIN) volume model.Design/methodology/approachThe lake water surface boundaries for each year were combined with field-observed water level data to generate a description of the underwater terrain. Time series LANDSAT images of 2001, 2011 and 2019 were used to extract the modified normalized difference water index (MNDWI) in GIS domain.FindingsThe MNDWI was 0.462 in 2001 which reduced to 0.240 in 2019. This shows that the lake water storage capacity shrank in the last 2 decades. This leads to a major problem, i.e. the storage capacity of the lake has been declining gradually from 20.95 million m3 in 2001 to ...

Journal of Pediatric Ophthalmology & Strabismus, 2007

Necrotizing Pseudomonas Infection of the Ocular Adnexa in an Infant With Leukocyte Adhesion Defec... more Necrotizing Pseudomonas Infection of the Ocular Adnexa in an Infant With Leukocyte Adhesion Defect To the Editors:A 14-day-old male neonate presented with left congenital nasolacrimal duct obstruction and was prescribed topical antibiotics. One week later, he developed an ulcer over the medial canthus of the left eye. Cultures from the wound grew Pseudomonas aeruginosa. Intravenous amikacin and metronidazole were commenced. The ulcerative lesion progressively destroyed the medial upper and lower eyelids, medial canthus, and part of the left lacrimal drainage system, and extended through the maxillary antrum to cause a hard-palate perforation (Fig. 1). Intravenous meropenem was added, and topical gentamicin was increased to every 2 hours. Artificial tears and lid taping were advised. Complete blood count revealed leukocytosis. Flow cytometry analysis of the 2 integrin revealed absent surface membrane expression of CD18 on polymorphonuclear leukocytes, confirming the diagnosis of leuk...

Acta Carsologica, 2012

Indija: Posledice �a �aloge pod�emne vode Sedimentacijski bazen Cuddapah obsega pomemben del južn... more Indija: Posledice �a �aloge pod�emne vode Sedimentacijski bazen Cuddapah obsega pomemben del južnega dela indijske države Andhra Pradesh. Proterozojske karbonate sestavljajo tri glavne enote, Vempalle dolomit ter Narji in Koilkuntla apnenci. Ti karbonati so lokalno pomembni, saj predstavljajo glavni vodni vir za namakanje in gospodinjstva ter pomemben vir gradbenih materialov. Poznavanje stopnje zakraselosti karbonatov je lahko pomembno pri upravljanju vodnih virov in inženirskih posegih na območju. Terenske raziskave so pokazale veliko zakraselost omenjenih karbonatov; pomemben del napajanja vodonosnikov poteka točkovno, skozi ponore, pretakanje pa se vrši v dobro razviti mreži kraških kanalov. Glavna faza razvoja krasa je verjetno potekala v preteklih, bolj vlažnih obdobjih. Procesi zakrasevanja v današnji polsušni klimi so posebej intenzivni na območju, kjer se na kras steka voda iz kvarcitnega zaledja. Zakraselost karbonatov bo treba upoštevati pri upravljanju območja in bodočih razvojnih projektih. Le na ta način se bomo lahko izognili težavam, kot so puščanje iz jezov, udiranje, napačna ocena vodnih zalog in podobno. Ključne besede: kras, kraški vodonosnik, jama, polsušno, zaloga podzemne vode, Indija.

A mutant MS301 of Aspergillus niger MS82 showed 1.5 to 2.5-fold improved endoglucanase and β-gluc... more A mutant MS301 of Aspergillus niger MS82 showed 1.5 to 2.5-fold improved endoglucanase and β-glucosidase activity when grown on crude lignocellulosic substrates under solid-state and submerged conditions. Indicators of thermal stability of enzymes (T m and T 1/2) showed that the wild type and mutant endoglucanase was more heat-resistant compared to β-glucosidase. However, mutant and parent enzymes shared almost the same values for melting temperatures and half-lives. Endoglucanase and β-glucosidase from both the strains showed optimum activity under acidic pH. Energy of activation (Ea) of mutant β-glucosidase was substantially lower than the parent enzyme while E a of mutant endoglucanase was slightly less than the parent. The lowered E a values can be attributed to the improved β-glucosidase activity of the mutant strain. Moreover, the MS301 enzymes were better in hydrolyzing purified and crude cellulosic materials than the parent MS82. Introduction Lignocellulosic biomass constitu...

Day 3 Wed, October 30, 2013, 2013

Continuous well performance monitoring plays a key role in making decision related to well workov... more Continuous well performance monitoring plays a key role in making decision related to well workover and production optimization. Well parameters and corresponding rates over a period of time will represent the change in well performance. Live Well models are useful for estimating the continuous well production rates. Well models become live if they get updated with changing fluid and reservoir properties along with proper calibration to latest well conditions. In general industry practice is to update the model manually; this is a tidious and time consuming process. Umm Gudair Field Development team implemented a real time system using available resources that integrates and runs workflows between corporate data base, well surveillance data base and well models. Workflows were implemented as part of the real time system to calculate the well parameters from sensor readings and update the models to run on daily basis, such that the models become live and production rates will be esti...

International Journal of Distributed and Parallel systems, 2011

In mobile ad hoc networks, there is no centralized infrastructure to monitor or allocate the reso... more In mobile ad hoc networks, there is no centralized infrastructure to monitor or allocate the resources used by the mobile nodes. The absence of any central coordinator makes the routing a complex one compared to cellular networks. The Ad hoc On Demand Distance Vector (AODV) routing algorithm is a routing protocol designed for ad hoc mobile devices. AODV uses an on demand approach for finding routes. AODV and most of the on demand ad hoc routing protocols use single route reply along the reverse path. Due to rapid changes of topology the route reply may not arrive to the source node resulting in sending several route request messages and degrading the performance of the routing protocol. The extended AODV called Reverse Ad Hoc On Demand Vector (R-AODV) protocol uses a reverse route discovery mechanism and performs well when link breakage is frequent. In this paper we compare the QoS parameters such as Throughput, Delay and Packet Delivery ratio of both traditional AODV and R-AODV using TCP New Reno as the traffic source. Simulation results show that R-AODV performs well when link breakage is frequent.

Groundwater Dynamics in Hard Rock Aquifers

Hydrogeology Journal, 2014

ABSTRACT About 3 % of India’s total land surface is occupied by carbonate rocks which are mostly ... more ABSTRACT About 3 % of India’s total land surface is occupied by carbonate rocks which are mostly karstified and constitute a significant source of groundwater. The groundwater drawn from these aquifers matches the water demand of ~35 million people living in 106 districts of the country and also the water needs of livestock, irrigation and industry. The studies on karst in India carried out so far have mostly addressed geology, hydrology and groundwater contamination. A literature survey suggests that there is a need for detailed research, applying new approaches and techniques for proper carbonate aquifer identification, characterization and management. Such specific approaches will improve modeling, exploitation and protection of karst groundwater. An overview of the research carried out on groundwater resources of karst formations in India is presented, which also throws light on the protection of karst aquifers from existing anthropogenic activities such as mining and groundwater over-exploitation.

Groundwater Dynamics in Hard Rock Aquifers

Stochastic Environmental Research and Risk Assessment, 2006

Journal of the Geological Society of India, 2011