Drilling muds with less environmental impact are highly desired over conventional diesel-based mud systems,especially in light of the emerging strict environmental laws.In this article,a novel oil-in-water(O/W)emulsio...Drilling muds with less environmental impact are highly desired over conventional diesel-based mud systems,especially in light of the emerging strict environmental laws.In this article,a novel oil-in-water(O/W)emulsion drilling fluid formulated with a methyl ester extracted from Indian mango seed oil was evaluated.The effect of the weight percent of different constituents of the emulsion/suspension including the oil phase,bentonite,and polyanionic cellulose polymer on the rheology and the fluid loss was examined.The methyl ester oil phase/mud system displayed superior physical,chemical,rheological and filtration properties relative to the diesel and the mango seed oil.Eco-toxicity of the methyl ester and diesel(O/W)emulsion mud systems was assessed using the acute lethal concentration test.The Indian mango methyl ester(O/W)emulsion mud displayed much less impact on fish population.Flow characteristics collected from the flow model at 85°C suggested excellent shear thinning behavior of the Indian mango methyl ester(IMME)(O/W)emulsion mud.Moreover,the IMME(O/W)emulsion displayed strong pseudoplastic behavior,an attractive feature in a drilling mud,with increasing clay content and polymer concentration.The methyl ester mud was thermally stable over a wide range of the constituent concentrations.Furthermore,a particle size analysis revealed that engineered drilling muds targeting suspension of particles with certain size range can be formulated by changing the volume fraction of the methyl ester in the mud system.展开更多
This work demonstrates the viability of the powder-mixed micro-electrochemical discharge machining(PMECDM) process to fabricate micro-holes on C103 niobium-based alloy for high temperature applications.Three processes...This work demonstrates the viability of the powder-mixed micro-electrochemical discharge machining(PMECDM) process to fabricate micro-holes on C103 niobium-based alloy for high temperature applications.Three processes are involved simultaneously i.e.spark erosion,chemical etching,and abrasive grinding for removal of material while the classical electrochemical discharge machining process involves double actions i.e.spark erosion,and chemical etching.The powder-mixed electrolyte process resulted in rapid material removal along with a better surface finish as compared to the classical microelectrochemical discharge machining(MECDM).Further,the results are optimized through a multiobjective optimization approach and study of the surface topography of the hole wall surface obtained at optimized parameters.In the selected range of experimental parameters,PMECDM shows a higher material removal rate(MRR) and lower surface roughness(R_(a))(MRR:2.8 mg/min and R_(a) of 0.61 μm) as compared to the MECDM process(MRR:2.01 mg/min and corresponding Raof 1.11 μm).A detailed analysis of the results is presented in this paper.展开更多
Introduction:Leiomyoma of urinary bladder is a rare entity and comprises 0.43%of all bladder tumors.Here we present our series of 3 cases and the related review of literature.Methods:3 cases of bladder leiomyoma prese...Introduction:Leiomyoma of urinary bladder is a rare entity and comprises 0.43%of all bladder tumors.Here we present our series of 3 cases and the related review of literature.Methods:3 cases of bladder leiomyoma presented over a period of 16 months in Osmania Medical College and Hospital.Detailed history was taken,physical examination,routine blood,urine and radiological investigations were done.Patients were treated by Trensurethral Resection(TUR)of the mass and histopathological analysis with Immunohistochemistry was done for all cases.Results:All 3 cases were females with mean age of 31.6 years.All cases were endovesical type,mass near bladder neck and presented with obstructive symptoms.Two cases presented with acute retention of urine.Radiological investigations in all patients suggested a possibility of leiomyoma and all cases had reduced urinary flow rates.Histopathology confirmed the diagnosis in all cases.No recurrence was found at one year of follow up.Conclusion:Leiomyoma of urinary bladder is a rare disorder which frequently occurs in middle aged females.Symptoms are related to its size and location,diagnosis is confirmed by histopathological analysis.Treatment is by surgery(mainly TUR).Prognosis of the disease is excellent.展开更多
基金acknowledge Schulich School of Engineering,The University of Calgary,for their support.
文摘Drilling muds with less environmental impact are highly desired over conventional diesel-based mud systems,especially in light of the emerging strict environmental laws.In this article,a novel oil-in-water(O/W)emulsion drilling fluid formulated with a methyl ester extracted from Indian mango seed oil was evaluated.The effect of the weight percent of different constituents of the emulsion/suspension including the oil phase,bentonite,and polyanionic cellulose polymer on the rheology and the fluid loss was examined.The methyl ester oil phase/mud system displayed superior physical,chemical,rheological and filtration properties relative to the diesel and the mango seed oil.Eco-toxicity of the methyl ester and diesel(O/W)emulsion mud systems was assessed using the acute lethal concentration test.The Indian mango methyl ester(O/W)emulsion mud displayed much less impact on fish population.Flow characteristics collected from the flow model at 85°C suggested excellent shear thinning behavior of the Indian mango methyl ester(IMME)(O/W)emulsion mud.Moreover,the IMME(O/W)emulsion displayed strong pseudoplastic behavior,an attractive feature in a drilling mud,with increasing clay content and polymer concentration.The methyl ester mud was thermally stable over a wide range of the constituent concentrations.Furthermore,a particle size analysis revealed that engineered drilling muds targeting suspension of particles with certain size range can be formulated by changing the volume fraction of the methyl ester in the mud system.
文摘This work demonstrates the viability of the powder-mixed micro-electrochemical discharge machining(PMECDM) process to fabricate micro-holes on C103 niobium-based alloy for high temperature applications.Three processes are involved simultaneously i.e.spark erosion,chemical etching,and abrasive grinding for removal of material while the classical electrochemical discharge machining process involves double actions i.e.spark erosion,and chemical etching.The powder-mixed electrolyte process resulted in rapid material removal along with a better surface finish as compared to the classical microelectrochemical discharge machining(MECDM).Further,the results are optimized through a multiobjective optimization approach and study of the surface topography of the hole wall surface obtained at optimized parameters.In the selected range of experimental parameters,PMECDM shows a higher material removal rate(MRR) and lower surface roughness(R_(a))(MRR:2.8 mg/min and R_(a) of 0.61 μm) as compared to the MECDM process(MRR:2.01 mg/min and corresponding Raof 1.11 μm).A detailed analysis of the results is presented in this paper.
文摘Introduction:Leiomyoma of urinary bladder is a rare entity and comprises 0.43%of all bladder tumors.Here we present our series of 3 cases and the related review of literature.Methods:3 cases of bladder leiomyoma presented over a period of 16 months in Osmania Medical College and Hospital.Detailed history was taken,physical examination,routine blood,urine and radiological investigations were done.Patients were treated by Trensurethral Resection(TUR)of the mass and histopathological analysis with Immunohistochemistry was done for all cases.Results:All 3 cases were females with mean age of 31.6 years.All cases were endovesical type,mass near bladder neck and presented with obstructive symptoms.Two cases presented with acute retention of urine.Radiological investigations in all patients suggested a possibility of leiomyoma and all cases had reduced urinary flow rates.Histopathology confirmed the diagnosis in all cases.No recurrence was found at one year of follow up.Conclusion:Leiomyoma of urinary bladder is a rare disorder which frequently occurs in middle aged females.Symptoms are related to its size and location,diagnosis is confirmed by histopathological analysis.Treatment is by surgery(mainly TUR).Prognosis of the disease is excellent.
