The coagulation process is one of the most important stages in water treatment plant, which involves many complex physical and chemical phenomena. Moreover, coagulant dosing rate is non-linearly correlated to raw wate...The coagulation process is one of the most important stages in water treatment plant, which involves many complex physical and chemical phenomena. Moreover, coagulant dosing rate is non-linearly correlated to raw water characteristics such as turbidity, conductivity, PH, temperature, etc. As such, coagulation reaction is hard or even impossible to control satisfactorily by conventional methods. Based on neural network and rule models, an expert system for determining the optimum chemical dosage rate is developed and used in a water treatment work, and the results of actual runs show that in the condition of satisfying the demand of drinking water quality, the usage of coagulant is lowered.展开更多
A kind of novel multi-layer piezoelectric actuator is proposed and integrated with controllable constrained damping treatment to perform hybrid vibration control.The governing equation of the system is derived based o...A kind of novel multi-layer piezoelectric actuator is proposed and integrated with controllable constrained damping treatment to perform hybrid vibration control.The governing equation of the system is derived based on the constitutive equations of elastic,viscoelastic and piezoelectric materials,which shows that the magnitude of control force exerted by multi-layer piezoelectric actuator is the quadratic function of the number of piezoelectric laminates used but in direct proportion to control voltage.This means that the multi-layer actuator can produce greater actuating force than that by piezoelectric laminate actuator with the same area under the identical control voltage.The optimal location placement of the multi-layer piezoelectric actuator is also discussed.As an example,the hybrid vibration control of a cantilever rectangular thin-plate is numerically simulated and carried out experimentally.The simulated and experimental results validate the power of multi-layer piezoelectric actuator and indicate that the present hybrid damping technique can effectively suppress the low frequency modal vibration of the experimental thin-plate structure.展开更多
The air conditioning system in the Umm Al-Qura University (Albdiya Campus) was conceived to be a district cooling by a remote chilled water plant. Recently, there are two chilled water plants in the university install...The air conditioning system in the Umm Al-Qura University (Albdiya Campus) was conceived to be a district cooling by a remote chilled water plant. Recently, there are two chilled water plants in the university installed strategically to provide chilled water to all the academic and administrative buildings of the university through distribution network with total capacity approximately of 12,000 tons of refrigeration. The plants were built based on cooling towers with open water cycle as heat rejection system. Water treatment chemicals has been used to protect the cooling systems from corrosion, scaling and microbiological fouling accompanied with dissolved and suspended water impurities. Different methods are being used to determine and control the treatment chemical concentrations and system performance indicators. Traditional chemical controller has drawback of indirect measurements and set points. The purpose of this paper is to present a solution to overcome the problems of traditional and conventional chemical treatment and control sys-tems. Central cooling plant number (1) assigned to perform experimental setup using new chemical treatment technology. Advanced automatic chemical treatment controller installed on condensers (1, 2 and 3), and certain key performance indicators were selected and monitored such as chemical and water consumption, power, energy saving, and maintaining system integrity and efficiency. Satisfactory results were obtained in terms of performance and cost of operation.展开更多
The influence of heat treatment on the strain-controlled fatigue behavior of cast NZ30 K alloy was investigated. Compared with the as-cast and solutionized(T4) alloys, the peak-aged(T6) and over-aged(T7)counterp...The influence of heat treatment on the strain-controlled fatigue behavior of cast NZ30 K alloy was investigated. Compared with the as-cast and solutionized(T4) alloys, the peak-aged(T6) and over-aged(T7)counterparts have a higher cyclic stress and a lower plastic strain value due to the precipitation strengthening. The as-cast and T4-treated alloys have a higher fatigue strength/yield strength ratio than the aged alloys, which is mainly attributed to their higher cyclic hardening. Under stress-controlled loading,the aged alloys show lower hysteresis energies than the as-cast and T4-treated counterparts, leading to longer fatigue lifetimes. For the T4-treated alloy, the cyclic hardening and fatigue failure are controlled by the dislocations-slip and twinning, while for both the as-cast and T6-treated counterparts, they are controlled by the dislocation-slip. For the T7-treated alloy, cyclic deformation and failure behavior are mainly dependent on dislocations-slip and grain boundary sliding.展开更多
Eutrophication is one of the important reasons for water pollution and is also the problem for water pollution treatment at home and abroad. This article takes an overview on various technical methods and their charac...Eutrophication is one of the important reasons for water pollution and is also the problem for water pollution treatment at home and abroad. This article takes an overview on various technical methods and their characteristics applicable for treatment and control of water eutrophication from the aspects of physics, chemistry, biochemistry and environmental factors regulation, and discusses the application and development trend for relevant technologies.展开更多
The Activated Sludge Process(ASP) exhibits highly nonlinear properties. The design of an automatic control system that is robust against disturbance of inlet wastewater flow rate and has short process settling times i...The Activated Sludge Process(ASP) exhibits highly nonlinear properties. The design of an automatic control system that is robust against disturbance of inlet wastewater flow rate and has short process settling times is a challenging matter. The proposed control method is an I-P modi fied controller automatic control system with state variable feedback and control canonical form simulation diagram for the process. A more stable response is achieved with this type of modern control. Settling times of 0.48 days are achieved for the concentration of microorganisms,(reference value step increase of 50 mg·L-1) and 0.01 days for the concentration of oxygen(reference value step increase of 0.1 mg·L-1). Fluctuations of concentrations of oxygen and microorganisms after an inlet disturbance of5 × 103m3·d-1are small. Changes in the reference values of oxygen and microorganisms(increases by 10%, 20% and 30%) show satisfactory response of the system in all cases. Changes in the value of inlet wastewater flow rate disturbance(increases by 10%, 25%, 50% and 100%) are stabilized by the control system in short time. Maximum percent overshoot is also taken in consideration in all cases and the largest value is 25% which is acceptable. The proposed method with I-P controller is better for disturbance rejection and process settling times compared to the same method using PI controller. This method can substitute optimal control systems in ASP.展开更多
OBJECTIVE: To investigate the use of Aloe vera(A.vera) for the treatment of gastroesophageal reflux disease(GERD) symptoms and compare its effects with those of omeprazole and ranitidine.METHODS: In this pilot, random...OBJECTIVE: To investigate the use of Aloe vera(A.vera) for the treatment of gastroesophageal reflux disease(GERD) symptoms and compare its effects with those of omeprazole and ranitidine.METHODS: In this pilot, randomized controlled trial, 79 subjects were allocated to A. vera syrup(standardized to 5.0 mg polysaccharide per m L of syrup)at a dose of 10 m L/d, omeprazole capsule(20 g/d)or ranitidine tablet(150 mg in a fasted state in the morning and 150 mg 30 min before sleep at night)for a period of 4 weeks. The frequencies of eight main symptoms of GERD(heartburn, food regurgitation, flatulence, belching, dysphagia, nausea,vomiting and acid regurgitation) were assessed at weeks 2 and 4 of the trial.RESULTS: A. vera was safe and well tolerated and reduced the frequencies of all the assessed GERD symptoms, with no adverse events requiring withdrawal.CONCLUSION: A. vera may provide a safe and effective treatment for reducing the symptoms of GERD.展开更多
Pulp and paper industry is responsible for large discharge of highly polluted effluents, which often be treated by biological treatment process. For biological treatment system, pH is an important environmental factor...Pulp and paper industry is responsible for large discharge of highly polluted effluents, which often be treated by biological treatment process. For biological treatment system, pH is an important environmental factor that can influence the activity of microorganisms. In general, the optimal pH for aerobic processes is around neutral pH (7_7.8) and for the anaerobic process is between 6.8_7.2. The control of pH is a difficult link in the biological treatment system due to its nonlinearity and large time-delay. Aiming at the difficult point in the pH control of the biological wastewater treatment system, a mathematical model of pH control is estab-lished in the essay. On this basis, a traditional PID control and a cascade control are adopted to carry out simulation and comparison with MATLAB. The results show that the cascade control has better comprehen-sive effect in terms of response speed, stability and disturbance resistance.展开更多
This paper presents a thorough review of control technologies that have been applied to wastewater treatment processes in the environmental engineering regime in the past four decades. It aims to provide a comprehensi...This paper presents a thorough review of control technologies that have been applied to wastewater treatment processes in the environmental engineering regime in the past four decades. It aims to provide a comprehensive technological review for both water engineering professionals and control specialists, giving rise to a suite of up-to-date pathways to impact this field in light of the classified technology hubs. The assessment was conducted with respect to linear control, linearizing control,nonlinear control, and artificial intelligence-based control. The application domain of each technology hub was summarized into a set of comparative tables for a holistic assessment. Challenges and perspectives were offered to these field engineers to help orient their future endeavor.展开更多
We consider a rift valley fever model with treatment in human and livestock populations and trapping in the vector (mosquito) population. The basic reproduction number R <sub>0</sub> is established and use...We consider a rift valley fever model with treatment in human and livestock populations and trapping in the vector (mosquito) population. The basic reproduction number R <sub>0</sub> is established and used to determine whether the disease dies out or is established in the three populations. When R <sub>0</sub> ≤ 1, the disease-free equilibrium is shown to be globally asymptotically stable and the disease does not spread and when R <sub>0</sub> > 1, a unique endemic equilibrium exists which is globally stable and the disease will spread. The mathematical model is analyzed analytically and numerically to obtain insight of the impact of intervention in reducing the burden of rift valley fever disease’s spread or epidemic and also to determine factors influencing the outcome of the epidemic. Sensitivity analysis for key parameters is also done.展开更多
Various kinds of pathogenic bacteria derived from the intestinal tract of animals exist in compost material like cow dung. In order to sterilize the pathogenic bacteria completely in compost material, the cow dung was...Various kinds of pathogenic bacteria derived from the intestinal tract of animals exist in compost material like cow dung. In order to sterilize the pathogenic bacteria completely in compost material, the cow dung was put into a heat treatment machine in pilot plan, and harmless condition in short time was examined. The results indicated, pathogenic indicator bacteria such as coliform bacteria, fecal coliform, Escherichia coli and salmonella were all 106 cfu/g dw at the beginning, died rapidly when cow dung temperature rose to above 50~C, and not detected at 54-68~C for 6-24 h heat treatment. Coliform bacteria and salmonella in heated cow dung were not detected by re-growth culture and enrichment culture examination. Moreover, it was hardly influenced on the fermentation ability of composting microbe, organic decomposition bacteria. During heat treatment, the mesophile decreased rapidly and the thermophile stabilized or increased, and the most of composting microbe were bacillus in cow dung by fluorescence microscope, this indicated that bacillus was dominator and composting microbe in composting process.展开更多
A large amount of residue from the water treatment process has gradually accumulated and thus caused serious environmental pollution in waterflood oilfields. The water treatment residue is a grey suspension, with a de...A large amount of residue from the water treatment process has gradually accumulated and thus caused serious environmental pollution in waterflood oilfields. The water treatment residue is a grey suspension, with a density of 1.08 g/cm^3, and mainly contains over 65% of light CaCO3, MgCO3, CaSO4, Fe2S3 and Ca(OH)2. This paper ascertains the effect of water treatment residue on core permeability and its application in oilfields. Coreflooding tests in laboratory were conducted in two artificial cores and one natural core. Core changes were evaluated by cast model image analysis, mercury injection method and scanning electron microscopy (SEM). Fresh water was injected into another natural core, which was plugged with water treatment residue, to determine the effective life. The results indicate that the water treatment residue has a strongly plugging capability, a resistance to erosion and a long effective life, and thus it can be used as a cheap raw material for profile control. In the past 8 years, a total of 60,164 m^3 of water treatment residue has been used for profile control of 151 well treatments, with a success ratio of 98% and an effective ratio of 83.2%. In the field tests, the profile control agent increased both starting pressure and injection pressure of injectors, and decreased the apparent water injectivity coefficient, significantly improving intake profiles and lengthening average service life of injectors. 28,381 tons of additional oil were recovered from these corresponding oil wells, with economic benefits of ¥3,069.55×10^4 (RMB) and a remarkable input-output ratio of 8.6:1.展开更多
Highly Active Antiretroviral Therapy (HAART) has changed the course of human immunodeficiency virus (HIV) treatments since its introduction. However, for many patients, long term continuous HAART is expensive and can ...Highly Active Antiretroviral Therapy (HAART) has changed the course of human immunodeficiency virus (HIV) treatments since its introduction. However, for many patients, long term continuous HAART is expensive and can include problems with drug toxicity and side effects, as well as increased drug resistance. Because of these reasons, some HIV infected patients will voluntarily terminate HAART. Some of these patients will also interrupt the continuous prescribed therapies for short or long periods. After discontinuing HAART, patients will usually experience a rapid increase in viral load coupled with an immediate decline in CD4+ counts. The canonical example of a patient undergoing unsupervised breaks in HAART is that of the “Berlin patient”. In this case, the patient was able to control viral load in the absence of treatment by cycling HAART on and off due to non-related infections. Due to this patient, interest in the use of structured treatment interruptions (STI) as a mechanism to regulate an HIV infection piqued. This paper describes an optimal control approach to determine STI regimen for HIV patients. The optimal STI was implemented in the context of the receding horizon control (RHC) using a mathematical model for the in-vivo dynamics of an HIV type 1 infection. Using available clinical data, we calibrate the model by estimating on a patient specific basis, a best estimable set of parameters using sensitivity analysis and subset selection. We demonstrate how customized STI protocols can be designed through the variation of control parameters on a patient specific basis.展开更多
Levodopa preparations remain the preferred drug for Parkinson's disease.However,long-term use of levodopa may lead to a series of motor complications.Previous studies have shown that the combination of levodopa and Z...Levodopa preparations remain the preferred drug for Parkinson's disease.However,long-term use of levodopa may lead to a series of motor complications.Previous studies have shown that the combination of levodopa and Zishenpingchan granules(consisting of Radix Rehmanniae preparata,Lycium barbarum,Herba Taxilli,Rhizoma Gastrodiae,Stiff Silkorm,Curcuma phaeocaulis,Radix Paeoniae Alba,Rhizoma Arisaematis,Scorpio and Centipede) can markedly improve dyskinesia and delay the progression of Parkinson's disease,with especially dramatic improvements of non-motor symptoms.However,the efficacy of this combination has not been confirmed by randomized controlled trials.The current study was approved by the Hospital Ethics Committee and was registered in the Chinese Clinical Trial Register(registration number:Chi CTR-INR-1701194).From December 2014 to December 2016,128 patients(72 males and 56 females,mean age of 65.78 ± 6.34 years) with Parkinson's disease were recruited from the Department of Neurology of Longhua Hospital and Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine in China.Patients were equally allocated into treatment and control groups.In addition to treatment with dopamine,patients in treatment and control groups were given Zishenpingchan granules or placebo,respectively,for 24 weeks.Therapeutic efficacy was assessed using the Unified Parkinson's Disease Rating Scale,on-off phenomenon,Hoehn-Yahr grade,Scales for Outcomes in Parkinson's disease–Autonomic,Parkinson's disease sleep scale,Hamilton Anxiety Scale,Hamilton Depression Scale,Mini-Mental State Examination,and the Parkinson's Disease Quality of Life Questionnaire.Artificial neural networks were used to determine weights at which to scale these parameters.Our results demonstrated that Zishenpingchan granules significantly reduced the occurrence of motor complications,and were useful for mitigating dyskinesia and non-motor symptoms of Parkinson's disease.This combination of Chinese and Western medicine has the potential to reduce levodopa dosages,and no obvious side effects were found.These findings indicate that Zishenpingchan granules can mitigate symptoms of Parkinson's disease,reduce toxic side effects of dopaminergic agents,and exert synergistic and detoxifying effects.展开更多
基金This work was supported by the project 863 ofChina(No.863-511092)
文摘The coagulation process is one of the most important stages in water treatment plant, which involves many complex physical and chemical phenomena. Moreover, coagulant dosing rate is non-linearly correlated to raw water characteristics such as turbidity, conductivity, PH, temperature, etc. As such, coagulation reaction is hard or even impossible to control satisfactorily by conventional methods. Based on neural network and rule models, an expert system for determining the optimum chemical dosage rate is developed and used in a water treatment work, and the results of actual runs show that in the condition of satisfying the demand of drinking water quality, the usage of coagulant is lowered.
基金This project is supported by National Natural Science Foundation of China(No.50275114,No.10476020).
文摘A kind of novel multi-layer piezoelectric actuator is proposed and integrated with controllable constrained damping treatment to perform hybrid vibration control.The governing equation of the system is derived based on the constitutive equations of elastic,viscoelastic and piezoelectric materials,which shows that the magnitude of control force exerted by multi-layer piezoelectric actuator is the quadratic function of the number of piezoelectric laminates used but in direct proportion to control voltage.This means that the multi-layer actuator can produce greater actuating force than that by piezoelectric laminate actuator with the same area under the identical control voltage.The optimal location placement of the multi-layer piezoelectric actuator is also discussed.As an example,the hybrid vibration control of a cantilever rectangular thin-plate is numerically simulated and carried out experimentally.The simulated and experimental results validate the power of multi-layer piezoelectric actuator and indicate that the present hybrid damping technique can effectively suppress the low frequency modal vibration of the experimental thin-plate structure.
文摘The air conditioning system in the Umm Al-Qura University (Albdiya Campus) was conceived to be a district cooling by a remote chilled water plant. Recently, there are two chilled water plants in the university installed strategically to provide chilled water to all the academic and administrative buildings of the university through distribution network with total capacity approximately of 12,000 tons of refrigeration. The plants were built based on cooling towers with open water cycle as heat rejection system. Water treatment chemicals has been used to protect the cooling systems from corrosion, scaling and microbiological fouling accompanied with dissolved and suspended water impurities. Different methods are being used to determine and control the treatment chemical concentrations and system performance indicators. Traditional chemical controller has drawback of indirect measurements and set points. The purpose of this paper is to present a solution to overcome the problems of traditional and conventional chemical treatment and control sys-tems. Central cooling plant number (1) assigned to perform experimental setup using new chemical treatment technology. Advanced automatic chemical treatment controller installed on condensers (1, 2 and 3), and certain key performance indicators were selected and monitored such as chemical and water consumption, power, energy saving, and maintaining system integrity and efficiency. Satisfactory results were obtained in terms of performance and cost of operation.
基金supported by the Key Research Project of Jiangxi Academy of Sciences(No.2017-YZD2-03)the Introduction Doctoral Program of Jiangxi Academy of Sciences(No.2016-YYB-09)the Collaborative innovation GSP Project of Jiangxi Academy of Sciences(No.2016-XTPH1-09)
文摘The influence of heat treatment on the strain-controlled fatigue behavior of cast NZ30 K alloy was investigated. Compared with the as-cast and solutionized(T4) alloys, the peak-aged(T6) and over-aged(T7)counterparts have a higher cyclic stress and a lower plastic strain value due to the precipitation strengthening. The as-cast and T4-treated alloys have a higher fatigue strength/yield strength ratio than the aged alloys, which is mainly attributed to their higher cyclic hardening. Under stress-controlled loading,the aged alloys show lower hysteresis energies than the as-cast and T4-treated counterparts, leading to longer fatigue lifetimes. For the T4-treated alloy, the cyclic hardening and fatigue failure are controlled by the dislocations-slip and twinning, while for both the as-cast and T6-treated counterparts, they are controlled by the dislocation-slip. For the T7-treated alloy, cyclic deformation and failure behavior are mainly dependent on dislocations-slip and grain boundary sliding.
基金Supported by the Project for Commission of Science and Technology of Chaoyang District in Beijing Municipality(KC1105)
文摘Eutrophication is one of the important reasons for water pollution and is also the problem for water pollution treatment at home and abroad. This article takes an overview on various technical methods and their characteristics applicable for treatment and control of water eutrophication from the aspects of physics, chemistry, biochemistry and environmental factors regulation, and discusses the application and development trend for relevant technologies.
文摘The Activated Sludge Process(ASP) exhibits highly nonlinear properties. The design of an automatic control system that is robust against disturbance of inlet wastewater flow rate and has short process settling times is a challenging matter. The proposed control method is an I-P modi fied controller automatic control system with state variable feedback and control canonical form simulation diagram for the process. A more stable response is achieved with this type of modern control. Settling times of 0.48 days are achieved for the concentration of microorganisms,(reference value step increase of 50 mg·L-1) and 0.01 days for the concentration of oxygen(reference value step increase of 0.1 mg·L-1). Fluctuations of concentrations of oxygen and microorganisms after an inlet disturbance of5 × 103m3·d-1are small. Changes in the reference values of oxygen and microorganisms(increases by 10%, 20% and 30%) show satisfactory response of the system in all cases. Changes in the value of inlet wastewater flow rate disturbance(increases by 10%, 25%, 50% and 100%) are stabilized by the control system in short time. Maximum percent overshoot is also taken in consideration in all cases and the largest value is 25% which is acceptable. The proposed method with I-P controller is better for disturbance rejection and process settling times compared to the same method using PI controller. This method can substitute optimal control systems in ASP.
基金Supported by the Clinical Trial Research CenterTehranIran
文摘OBJECTIVE: To investigate the use of Aloe vera(A.vera) for the treatment of gastroesophageal reflux disease(GERD) symptoms and compare its effects with those of omeprazole and ranitidine.METHODS: In this pilot, randomized controlled trial, 79 subjects were allocated to A. vera syrup(standardized to 5.0 mg polysaccharide per m L of syrup)at a dose of 10 m L/d, omeprazole capsule(20 g/d)or ranitidine tablet(150 mg in a fasted state in the morning and 150 mg 30 min before sleep at night)for a period of 4 weeks. The frequencies of eight main symptoms of GERD(heartburn, food regurgitation, flatulence, belching, dysphagia, nausea,vomiting and acid regurgitation) were assessed at weeks 2 and 4 of the trial.RESULTS: A. vera was safe and well tolerated and reduced the frequencies of all the assessed GERD symptoms, with no adverse events requiring withdrawal.CONCLUSION: A. vera may provide a safe and effective treatment for reducing the symptoms of GERD.
文摘Pulp and paper industry is responsible for large discharge of highly polluted effluents, which often be treated by biological treatment process. For biological treatment system, pH is an important environmental factor that can influence the activity of microorganisms. In general, the optimal pH for aerobic processes is around neutral pH (7_7.8) and for the anaerobic process is between 6.8_7.2. The control of pH is a difficult link in the biological treatment system due to its nonlinearity and large time-delay. Aiming at the difficult point in the pH control of the biological wastewater treatment system, a mathematical model of pH control is estab-lished in the essay. On this basis, a traditional PID control and a cascade control are adopted to carry out simulation and comparison with MATLAB. The results show that the cascade control has better comprehen-sive effect in terms of response speed, stability and disturbance resistance.
基金supported by the Fulbright Visiting Scholar Program from the Department of State in the U.S.
文摘This paper presents a thorough review of control technologies that have been applied to wastewater treatment processes in the environmental engineering regime in the past four decades. It aims to provide a comprehensive technological review for both water engineering professionals and control specialists, giving rise to a suite of up-to-date pathways to impact this field in light of the classified technology hubs. The assessment was conducted with respect to linear control, linearizing control,nonlinear control, and artificial intelligence-based control. The application domain of each technology hub was summarized into a set of comparative tables for a holistic assessment. Challenges and perspectives were offered to these field engineers to help orient their future endeavor.
文摘We consider a rift valley fever model with treatment in human and livestock populations and trapping in the vector (mosquito) population. The basic reproduction number R <sub>0</sub> is established and used to determine whether the disease dies out or is established in the three populations. When R <sub>0</sub> ≤ 1, the disease-free equilibrium is shown to be globally asymptotically stable and the disease does not spread and when R <sub>0</sub> > 1, a unique endemic equilibrium exists which is globally stable and the disease will spread. The mathematical model is analyzed analytically and numerically to obtain insight of the impact of intervention in reducing the burden of rift valley fever disease’s spread or epidemic and also to determine factors influencing the outcome of the epidemic. Sensitivity analysis for key parameters is also done.
文摘Various kinds of pathogenic bacteria derived from the intestinal tract of animals exist in compost material like cow dung. In order to sterilize the pathogenic bacteria completely in compost material, the cow dung was put into a heat treatment machine in pilot plan, and harmless condition in short time was examined. The results indicated, pathogenic indicator bacteria such as coliform bacteria, fecal coliform, Escherichia coli and salmonella were all 106 cfu/g dw at the beginning, died rapidly when cow dung temperature rose to above 50~C, and not detected at 54-68~C for 6-24 h heat treatment. Coliform bacteria and salmonella in heated cow dung were not detected by re-growth culture and enrichment culture examination. Moreover, it was hardly influenced on the fermentation ability of composting microbe, organic decomposition bacteria. During heat treatment, the mesophile decreased rapidly and the thermophile stabilized or increased, and the most of composting microbe were bacillus in cow dung by fluorescence microscope, this indicated that bacillus was dominator and composting microbe in composting process.
文摘A large amount of residue from the water treatment process has gradually accumulated and thus caused serious environmental pollution in waterflood oilfields. The water treatment residue is a grey suspension, with a density of 1.08 g/cm^3, and mainly contains over 65% of light CaCO3, MgCO3, CaSO4, Fe2S3 and Ca(OH)2. This paper ascertains the effect of water treatment residue on core permeability and its application in oilfields. Coreflooding tests in laboratory were conducted in two artificial cores and one natural core. Core changes were evaluated by cast model image analysis, mercury injection method and scanning electron microscopy (SEM). Fresh water was injected into another natural core, which was plugged with water treatment residue, to determine the effective life. The results indicate that the water treatment residue has a strongly plugging capability, a resistance to erosion and a long effective life, and thus it can be used as a cheap raw material for profile control. In the past 8 years, a total of 60,164 m^3 of water treatment residue has been used for profile control of 151 well treatments, with a success ratio of 98% and an effective ratio of 83.2%. In the field tests, the profile control agent increased both starting pressure and injection pressure of injectors, and decreased the apparent water injectivity coefficient, significantly improving intake profiles and lengthening average service life of injectors. 28,381 tons of additional oil were recovered from these corresponding oil wells, with economic benefits of ¥3,069.55×10^4 (RMB) and a remarkable input-output ratio of 8.6:1.
文摘Highly Active Antiretroviral Therapy (HAART) has changed the course of human immunodeficiency virus (HIV) treatments since its introduction. However, for many patients, long term continuous HAART is expensive and can include problems with drug toxicity and side effects, as well as increased drug resistance. Because of these reasons, some HIV infected patients will voluntarily terminate HAART. Some of these patients will also interrupt the continuous prescribed therapies for short or long periods. After discontinuing HAART, patients will usually experience a rapid increase in viral load coupled with an immediate decline in CD4+ counts. The canonical example of a patient undergoing unsupervised breaks in HAART is that of the “Berlin patient”. In this case, the patient was able to control viral load in the absence of treatment by cycling HAART on and off due to non-related infections. Due to this patient, interest in the use of structured treatment interruptions (STI) as a mechanism to regulate an HIV infection piqued. This paper describes an optimal control approach to determine STI regimen for HIV patients. The optimal STI was implemented in the context of the receding horizon control (RHC) using a mathematical model for the in-vivo dynamics of an HIV type 1 infection. Using available clinical data, we calibrate the model by estimating on a patient specific basis, a best estimable set of parameters using sensitivity analysis and subset selection. We demonstrate how customized STI protocols can be designed through the variation of control parameters on a patient specific basis.
基金supported by a grant from Major Project of Shanghai Committee of Science and Technology of China,No.15401970100a grant from the National Natural Science Foundation of China(General Program),No.81673726+2 种基金a grant from the Project of Shanghai Committee of Science and Technology of China,No.17401934600a grant from Longhua Scholar Plan of National Traditional Chinese Medicine Clinical Base of China,No.LYTD-34a grant from Shanghai Traditional Chinese Medicine Science and Technology Innovation Project,No.ZYKC201601002
文摘Levodopa preparations remain the preferred drug for Parkinson's disease.However,long-term use of levodopa may lead to a series of motor complications.Previous studies have shown that the combination of levodopa and Zishenpingchan granules(consisting of Radix Rehmanniae preparata,Lycium barbarum,Herba Taxilli,Rhizoma Gastrodiae,Stiff Silkorm,Curcuma phaeocaulis,Radix Paeoniae Alba,Rhizoma Arisaematis,Scorpio and Centipede) can markedly improve dyskinesia and delay the progression of Parkinson's disease,with especially dramatic improvements of non-motor symptoms.However,the efficacy of this combination has not been confirmed by randomized controlled trials.The current study was approved by the Hospital Ethics Committee and was registered in the Chinese Clinical Trial Register(registration number:Chi CTR-INR-1701194).From December 2014 to December 2016,128 patients(72 males and 56 females,mean age of 65.78 ± 6.34 years) with Parkinson's disease were recruited from the Department of Neurology of Longhua Hospital and Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine in China.Patients were equally allocated into treatment and control groups.In addition to treatment with dopamine,patients in treatment and control groups were given Zishenpingchan granules or placebo,respectively,for 24 weeks.Therapeutic efficacy was assessed using the Unified Parkinson's Disease Rating Scale,on-off phenomenon,Hoehn-Yahr grade,Scales for Outcomes in Parkinson's disease–Autonomic,Parkinson's disease sleep scale,Hamilton Anxiety Scale,Hamilton Depression Scale,Mini-Mental State Examination,and the Parkinson's Disease Quality of Life Questionnaire.Artificial neural networks were used to determine weights at which to scale these parameters.Our results demonstrated that Zishenpingchan granules significantly reduced the occurrence of motor complications,and were useful for mitigating dyskinesia and non-motor symptoms of Parkinson's disease.This combination of Chinese and Western medicine has the potential to reduce levodopa dosages,and no obvious side effects were found.These findings indicate that Zishenpingchan granules can mitigate symptoms of Parkinson's disease,reduce toxic side effects of dopaminergic agents,and exert synergistic and detoxifying effects.