Hydrodynamic cavitaion venturi tube technique is used for pico and nano bubble generations in coal column flotation. In order to determine the optimal design of hydrodynamic cavitation venture tube for pico and nano b...Hydrodynamic cavitaion venturi tube technique is used for pico and nano bubble generations in coal column flotation. In order to determine the optimal design of hydrodynamic cavitation venture tube for pico and nano bubble generation, a four-factor three-level Central Composite Design of Experimental was conducted for investigating four important design parameters of cavitation venturi tube governing the median size and the volume of pico and nano bubbles. The test results showed that maximum volume of pico and nano bubbles, 65–75%, and minimum mean pico and nano bubble size,150–240 nm, were achieved at the medium ratio of the diameter of outlet of the venturi-tube and diameter of throat(3–4), medium outlet angle(11–13°), high inlet angle(26–27°) and high ratio of the length of the throat and the diameter of throat(2.3–3). Study the effects of the producing pico and nano bubbles on fine coal flotation was performed in a 5 cm diameter 260 cm height flotation column. The optimal percentage of pico and nano bubbles was about 70%, which produced maximum combustible material recovery of 86% with clean coal ash content of 11.7%.展开更多
Objective To report the results of treatment of osteoid osteomas with wide surgical excision and CT-guided less invasive surgeries.Methods Forty-two patients were entered into this prospective study between Jan.1998 a...Objective To report the results of treatment of osteoid osteomas with wide surgical excision and CT-guided less invasive surgeries.Methods Forty-two patients were entered into this prospective study between Jan.1998 and Jan.2008.Nineteen patients underwent wide surgical excision.The lesions were in the femur(n=9),tibia(n=7),and humerus(n=3).The mean lesion diameter was(9.2±2.3)mm(range,7-16mm).Twenty-three patients(15 males and 8 females)underwent CT-guided less invasive surgeries procedures.The lesions were in the femur(n=9),tibia(n=6),acetabulum(n=4)and humerus(n=4).The mean lesion diameter was(8.1±2.7)mm(range,6-15mm).Among these 23 patients,20 patients were performed by core drill excision.Three patients were performed by radiofrequency ablation.Follow-up ranged from 16 to 68 months(mean,35 months)to assess pain,neurovascular damage,pathological fracture,movement,and recurrence.Results were categorized as success(persistent complete relief of pain)and failure(absent or incomplete relief of pain,requiring additional treatment).Results The success rates were 89%(17/19)after wide surgical excision and 96%(22/23)after less invasive surgeries,respectively,and the difference was not significant(P>0.05).Patients were hospitalized for average 8.3 d(5-15d)after wide surgical excision and 3.2d(3-5d)after less invasive surgeries(P<0.05).There were no complications such as sepsis,pathological fracture,or neurovascular damage.No further recurrences were observed during follow-up.Conclusion Less invasive surgeries has obvious advantages such as reduced cost,shorter stay in hospital and rapid convalescence.Core-drill excision can obtain sufficient material for pathologic examination.展开更多
基金West Virginia State Coal and Energy Research Bureau(WVCERB)the Department of Mining Engineering,West Virginia University
文摘Hydrodynamic cavitaion venturi tube technique is used for pico and nano bubble generations in coal column flotation. In order to determine the optimal design of hydrodynamic cavitation venture tube for pico and nano bubble generation, a four-factor three-level Central Composite Design of Experimental was conducted for investigating four important design parameters of cavitation venturi tube governing the median size and the volume of pico and nano bubbles. The test results showed that maximum volume of pico and nano bubbles, 65–75%, and minimum mean pico and nano bubble size,150–240 nm, were achieved at the medium ratio of the diameter of outlet of the venturi-tube and diameter of throat(3–4), medium outlet angle(11–13°), high inlet angle(26–27°) and high ratio of the length of the throat and the diameter of throat(2.3–3). Study the effects of the producing pico and nano bubbles on fine coal flotation was performed in a 5 cm diameter 260 cm height flotation column. The optimal percentage of pico and nano bubbles was about 70%, which produced maximum combustible material recovery of 86% with clean coal ash content of 11.7%.
文摘Objective To report the results of treatment of osteoid osteomas with wide surgical excision and CT-guided less invasive surgeries.Methods Forty-two patients were entered into this prospective study between Jan.1998 and Jan.2008.Nineteen patients underwent wide surgical excision.The lesions were in the femur(n=9),tibia(n=7),and humerus(n=3).The mean lesion diameter was(9.2±2.3)mm(range,7-16mm).Twenty-three patients(15 males and 8 females)underwent CT-guided less invasive surgeries procedures.The lesions were in the femur(n=9),tibia(n=6),acetabulum(n=4)and humerus(n=4).The mean lesion diameter was(8.1±2.7)mm(range,6-15mm).Among these 23 patients,20 patients were performed by core drill excision.Three patients were performed by radiofrequency ablation.Follow-up ranged from 16 to 68 months(mean,35 months)to assess pain,neurovascular damage,pathological fracture,movement,and recurrence.Results were categorized as success(persistent complete relief of pain)and failure(absent or incomplete relief of pain,requiring additional treatment).Results The success rates were 89%(17/19)after wide surgical excision and 96%(22/23)after less invasive surgeries,respectively,and the difference was not significant(P>0.05).Patients were hospitalized for average 8.3 d(5-15d)after wide surgical excision and 3.2d(3-5d)after less invasive surgeries(P<0.05).There were no complications such as sepsis,pathological fracture,or neurovascular damage.No further recurrences were observed during follow-up.Conclusion Less invasive surgeries has obvious advantages such as reduced cost,shorter stay in hospital and rapid convalescence.Core-drill excision can obtain sufficient material for pathologic examination.
