To review the preventive approaches for recurrence after curative resection of hepatic metastases from colorectal carcinoma, we have summarized all available publications reporting randomized control trials (RCTs) cov...To review the preventive approaches for recurrence after curative resection of hepatic metastases from colorectal carcinoma, we have summarized all available publications reporting randomized control trials (RCTs) covered in PubMed. The treatment approaches presented above include adjuvant intrahepatic arterial infusion chemotherapy, systemic chemotherapy, neoadjuvant chemotherapy, and immunotherapy. Although no standard treatment has been established, several approaches present promising results, which are both effective and tolerable in post-hepatectomy patients. Intrahepatic arterial infusion chemotherapy should be regarded as effective and tolerable and it increases overall survival (OS) and disease free survival (DFS) of patients, while 5-fluorouracil-based systemic chemotherapy has not shown any significant survival benefit. Fortunately chemotherapy combined with hepatic arterial infusion and intravenous infusion has shown OS and DFS benefit in many researches. Few neoadjuvant RCT studies have been conducted to evaluate its effect on prolonging survivals although many retrospective studies and case reports are published in which unresectable colorectal liver metastases are downstaged and made resectable with neoadjuvant chemotherapy. Liver resection supplemented with immunotherapy is associated with optimal results; however, it is also questioned by others. In conclusion, several adjuvant approaches have been studied for their efficacy on recurrence after hepatectomy for liver metastases from colorectal cancer (CRC), but multi-centric RCT is still needed for further evaluation on their efficacy and systemic or local toxicities. In addition, new adjuvant treatment should be investigated to provide more effective and tolerable methods for the patients with resectable hepatic metastases from CRC.展开更多
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
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
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
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
At the present stage, the social economy in China has developed by leaps and bounds. China's pig industry has been well developed un-der the background of this era. However, the number of pig diseases increases du...At the present stage, the social economy in China has developed by leaps and bounds. China's pig industry has been well developed un-der the background of this era. However, the number of pig diseases increases due to the influence of many factors, and highly pathogenic porcine reproductive and respiratory syndrome(HP-PRRS) is one of the very common diseases, causing growing mortality rate of pigs. The disease increases the economic loss of pig industry to a large extent, and brings difficulties in prevention and control of pig diseases. The staff must analyze and sum-marize the basic characteristics of pig diseases, and combine some practical problems in prevention and control of pig disease to find effective mea-sures. The scope and scale of pig production in different parts of China have been continuously expanded under the background of further develop-ment of pig industry in the new era. But for pig production, pig disease has been a problem that delays its further development. Related personnel must analyze and summarize the status quo of HP-PRRS, to find effective prevention measures and strategy.展开更多
[ Objective ] The aim was to study the influence of filamentous algae on the process of water ecological purification. [ Method ] The occurrence mechanism of filamentous algae and its ecological system were summarized...[ Objective ] The aim was to study the influence of filamentous algae on the process of water ecological purification. [ Method ] The occurrence mechanism of filamentous algae and its ecological system were summarized and analyzed. Considering the ecological purification in north- ern Jiangsu, the occurrence and prevention of filamentous algae in water, the method to prevent filamentous algae in polluted water was discussed. [ Result] The results showed that by measures of improving planting density, regular harvesting, and water flow state control before the filamentous algae blooming period, together with improving local pH value, light interference and ecological control during the blooming period, can effectively control the filamentous algae blooming. [ Condusion] The study of the happening mechanism of filamentous algae provided theoretical references and the technical basis in the work of filamentous algae prevention and control.展开更多
The black soil region of Northeast China is one of the most important food production bases and commodity grain bases in China. However, the continual loss and degradation of precious black soil resources has led to d...The black soil region of Northeast China is one of the most important food production bases and commodity grain bases in China. However, the continual loss and degradation of precious black soil resources has led to direct threats to national food security and regional sustainable development. Therefore, it is necessary to summarize integrated prevention and control experience of small watersheds in black soil region of Northeast China. Tongshuang small watershed, a typical watershed in rolling hills of typical black soil areas in Northeast China, is selected as the study area. Based on nearly 50 years' experience in prevention and control of soil and water loss, the structures and overall benefits of an integrated prevention and control system for soil and water loss are investigated. Then, the 'three defense lines' tri-dimensional protection system with reasonable allocation of different types of soil and water control measures from the hill top to gully is systematically analyzed. The first line on the top hill can weaken and block uphill runoff and sediment, hold water resources and improve soil property. The second line on the hill can truncate slope length, slow down the runoff velocity and reduce erosion energy. The third line in the gully is mainly composed of waterfall engineering, which can inhibit soil erosion and restore land resources. The 'three defense lines' system is feasible for soil and water loss control of small watersheds in the typical black soil region of Northeast China. Through the application of the in Tongshuang small watershed, There are effective improvements in ecological conditions in Tongshuang small watershed after the application of 'three defense lines' soil and water control system. Moreover, the integrated treatment paradigm for soil and water loss in typical black soil region is compared with that in loess region. The results of this study could offer references and experiences for other small watersheds in typical black soil region of Northeast China.展开更多
Background: Novel coronavirus pneumonia (NCP) and osteoporotic vertebral compression fractures (OVCF) are the high incidences of diseases in the elderly. During the epidemic period, if not treated in time, the complic...Background: Novel coronavirus pneumonia (NCP) and osteoporotic vertebral compression fractures (OVCF) are the high incidences of diseases in the elderly. During the epidemic period, if not treated in time, the complications are high and the mortality is high. If we do not pay attention to infection prevention and control in pre-hospital emergency care, it will lead to the first time infection of medical staff and in-hospital cross infection in emergency outpatient receiving area. The correct consideration of both and the establishment of perfect pre-hospital emergency treatment and infection prevention and control synchronous strategy is an important premise to ensure the stable, orderly and safe medical treatment. Objective: To explore the effect of synchronous implementation of pre-hospital emergency care, nursing and infection pre-vention and control for senile OVCF during the epidemic. In order to improve the efficiency of pre-hospital emergency care and prevent the spread of infection. Method: A total of 92 elderly patients with OVCF who received pre-hospital treatment in 18 hospitals in Zhangjiakou City during the epidemic prevention and control period from January 2020 to November 2022 and met the inclusion criteria were selected as research objects, including 24 males and 68 females, aged 65 - 82 (74.2 ± 2.2) years. All patients were associated with concomitant injuries and underlying diseases. All patients in this group underwent predictive pre-hospital rescue and infection prevention and control procedures. Results: All the 92 elderly patients with OVCF received timely pre-hospital treatment during the epidemic period, and no aggravation occurred of the 92 patients, 35 were in the high risk area, 10 were in the medium risk area, and 47 were in the low risk area. Exclude OVCF for NCP Patients were treated according to the conventional diagnosis and treatment principles. Suspected and confirmed cases are transferred to designated surgical hospitals for treatment. All patients were followed up 3 months, 6 months and 12 months after treatment. There was no death rate, high satisfaction of pre-hospital first aid, high diagnostic accuracy, and good curative effect. None of the rescue personnel had any infection rate, and no hospital infection transmission and nosocomial cross infection occurred. Conclusion: It is the first step to safely treat patients and prevent cross infection to establish a perfect synchronous strategy of pre-hospital first aid and infection prevention and control.展开更多
Background:A growing number of randomized controlled trials(RCTs)have explored the significance of adjusting constitution for preventive treatment of disease in traditional Chinese medicine(TCM).In this study,we sough...Background:A growing number of randomized controlled trials(RCTs)have explored the significance of adjusting constitution for preventive treatment of disease in traditional Chinese medicine(TCM).In this study,we sought to comprehensively analyze the characteristics of these RCTs.Methods:All RCTs related to constitutional adjustment and preventive treatment of disease were included in the study.Literature was screened searching seven databases,including Pubmed,Web of Science,Embase,SinoMed,CNKI,Chongqing VIP,and Wangfang Database,from inception to December 2018.Data pertaining to bibliometrics,participants,and interventions were extracted and analyzed.Results:Two hundred and forty papers were published between 2007 and 2018,involving 240 RCTs with 55977 total participants.Sample size in these RCTs ranged from 30 to 7800.Among them,59 RCTs addressed disease prevention prior to onset involving 11 healthy states of participants,mainly for general health or sub-health population(40.68%)using health care and non-drug therapy.In control the development of existing disease(n Z 174),59 diseases were involved.Based on the number of RCTs and sample sizes,diseases including type 2 diabetes mellitus,primary hypertension,nonalcoholic fatty liver disease,and hyperlipoproteinemia accounted for 51.15%of the total patients studied.Drug therapy as an intervention was frequently used.In preventing recurrence after recovery(n Z 7),over 4 kinds of health status in participants were involved.Drug therapy combined with health care was mostly used.Most RCTs reported positive outcomes,with only one reporting negative findings(1/240).Conclusion:The number of RCTs of constitutional adjustment on preventive treatment of disease has gradually increased since 2012.Participants and intervention measures from the above-mentioned types of RCTs exhibit their own characteristics.Future systematic reviews or meta-analyses on constitutional adjustment for preventive treatment of disease are warranted.展开更多
The aim was to develop green strawberry varieties,control soil-borne diseases from facility strawberry continuous cropping,improve the safety and quality of strawberries and promote the healthy and stable development ...The aim was to develop green strawberry varieties,control soil-borne diseases from facility strawberry continuous cropping,improve the safety and quality of strawberries and promote the healthy and stable development of the strawberry industry. Based on the production practices in recent years,we summarized the physical-biological collaborative prevention and control technology for the disease of facility strawberry continuous cropping facilities,established the technical goals,the main types of soil-borne diseases,and the physical-biological collaborative control prevention and control technologies,mainly including the specific methods and technical points of solar high temperature disinfection technology and biological bacterial fertilizer( agent) treatment technology.展开更多
By summarizing the composition,classification,and performance characterization of functional adhesive materials,the adhesion mechanisms of functional adhesive materials,such as adsorption/surface reaction,diffusion,me...By summarizing the composition,classification,and performance characterization of functional adhesive materials,the adhesion mechanisms of functional adhesive materials,such as adsorption/surface reaction,diffusion,mechanical interlocking,and electrostatic adsorption,are expounded.The research status of these materials in oil and gas drilling and production engineering field such as lost circulation prevention/control,wellbore stabilization,hydraulic fracturing,and profile control and water plugging,and their application challenges and prospects in oil and gas drilling and production are introduced comprehensively.According to the applications of functional adhesive materials in the field of oil and gas drilling and production at this stage,the key research directions of functional adhesive materials in the area of oil and gas drilling and production are proposed:(1)blending and modifying thermoplastic resins or designing curable thermoplastic resins to improve the bonding performance and pressure bearing capacity of adhesive lost circulation materials;(2)introducing low-cost adhesive groups and positive charge structures into polymers to reduce the cost of wellbore strengthening agents and improve their adhesion performance on the wellbore;(3)introducing thermally reversible covalent bond into thermosetting resin to prevent backflow of proppant and improve the compressive strength of adhesive proppant;(4)introducing thermally reversible covalent bonds into thermoplastic polymers to improve the temperature resistance,salt-resistance and water shutoff performance of adhesive water shutoff agents.展开更多
Shale gas reservoirs are unconventional tight gas reservoirs,in which horizontal wells and hydraulic fracturing are required to achieve commercial development.The fracture networks created by hydraulic fracturing can ...Shale gas reservoirs are unconventional tight gas reservoirs,in which horizontal wells and hydraulic fracturing are required to achieve commercial development.The fracture networks created by hydraulic fracturing can increase the drainage area extensively to enhance shale gas recovery.However,large volumes of fracturing fluid that is difficult to flow back to the surface and remained in the shale formation,will inevitably lead to damages of the shale formations and limit the effectiveness of stimulation.Supercritical water(SCW)treatment after hydraulic fracturing is a new method to enhance shale gas recovery by using appropriate heat treatment methods to the specific formation to convert the retained fracturing fluid into a supercritical state(at temperatures in excess of 373.946°C and pressures in excess of 22.064 MPa).An experiment was conducted to simulate the reaction between shale and SCW,and the capacity of SCW treatment to enhance the permeability of the shale was evaluated by measuring the response of the shale porosity and permeability on SCW treatment.The experimental results show that the shale porosity and permeability increase by 213.43%and 2198.37%,respectively.The pore structure alteration and permeability enhancement of the shale matrix were determined by analyzing the changes in pore structure and mineral composition after SCW treatment.The mechanisms that affect pore structure and mineral composition include oxidative catalysis decomposition of organic matters and reducing minerals,acid-catalyzed decomposition of carbonate minerals and feldspar minerals,hydrothermal catalysis induced fracture extension and cementation weakening induced fracture extension.SCW treatment converts harm into a benefit by reducing the intrusion of harmful substances into the shale formation,which will broaden the scope and scale of shale formation stimulation.展开更多
Man made activities are changing environment of our planet earth.Various methods are used to reduce the environmental pollution.In this paper the methods of air/water/soil pollution mitigation/reduction using electrom...Man made activities are changing environment of our planet earth.Various methods are used to reduce the environmental pollution.In this paper the methods of air/water/soil pollution mitigation/reduction using electromagnetic fields is discussed.Air/water/soil contains ions and the energy transfer for living organisms takes place by ion exchange processes.Ions are affected by electric/magnetic fields.Many investigators展开更多
The shortage of water resources is severe in Beijing. The shortage of eco-environmental water and the sewage discharge over the environmental capacity are main bottlenecks that restrict the improvement of water enviro...The shortage of water resources is severe in Beijing. The shortage of eco-environmental water and the sewage discharge over the environmental capacity are main bottlenecks that restrict the improvement of water environment. The reuse of wastewater could not only reduce the discharge of pollutants,but it could also increase the consumption of eco-environmental water. Therefore the reuse of wastewater is an important approach to improve the water environmental quality. Combined with the formulation process of Regulations of Beijing on Prevention and Control of Water Pollution,the current situations of prevention and control of water pollution in Beijing,the discharge of pollutant,water environmental quality,the population and economic development and water resources and so on were analyzed. And the bottlenecks that restricted the improvement of water environmental quality were found. And the necessity of solving the control of water pollution by reusing the wastewater and ensuring the consumption of eco-environmental water was analyzed from the perspective of the control of water pollution. And some legislative countermeasures were put forward,which provided new ideas for solving the problem of the prevention and control of water pollution and improving the water environmental quality. It was of important reference values for local governments( especially water-deficient regions) to make relative polices or plans of water pollution control and water environmental protection.展开更多
Water supply project of drawing from the Songhua River in central cities of Jilin is taken as research object.On the basis of analyzing project characteristics and natural conditions of the project area,site selection...Water supply project of drawing from the Songhua River in central cities of Jilin is taken as research object.On the basis of analyzing project characteristics and natural conditions of the project area,site selection of waste slag yard of water diversion project and design of water and soil conservation measures are discussed.Rationality of site selection of waste slag yard and pertinence of prevention and control measures of water and soil loss in waste slag yard are analyzed,and comprehensive utilization of waste slag in large-scale production and construction projects is explored.展开更多
Hemp sesbania (Sesbania exaltata) plants (>30 cm tall) sprayed with hot water (45°C – 95°C), followed by spray applications of fungal spores of Colletotrichum truncatum (CT) at 1.0 × 107 spore...Hemp sesbania (Sesbania exaltata) plants (>30 cm tall) sprayed with hot water (45°C – 95°C), followed by spray applications of fungal spores of Colletotrichum truncatum (CT) at 1.0 × 107 spores/ml-1 and 22°C – 25°C, suspended either in: 0.2% Silwet L-77 surfactant (SW);unrefined corn oil (CO)/distilled water (1:1, v:v);or 0.2% SW in CO were controlled by 80% - 95%, 12 days after treatment (DAT) under greenhouse conditions. These treatments also reduced dry weight accumulation of this weed. Plants treated with hot water without CT were also injured at temperatures ≥35°C (5% mortality), and 60% mortality at 95°C. Artificial dew treatments (25°C, 12 h), imposed on plants after the treatment protocols above, had little or no effect on weed mortality or dry weight reduction compared to treated plants without dew. Under field conditions, 85% control of hemp sesbania was achieved 12 - 15 DAT when a pre-treatment with hot water (65°C) was followed immediately with a CT application at the spore concentration as described above. Plants in field tests treated with CT without a hot water treatment were visually unaffected, with no mortality or plant biomass reductions recorded 15 DAT. These results suggest that use of hot water may be an important tool for improving the infectivity and bioherbicidal potential of some plant pathogens.展开更多
Accumulation of float coal dust(FCD)in underground mines is an explosion hazard that affects all underground coal mine workers.While this hazard is addressed by the application of rock dust,inadequate rock dusting pra...Accumulation of float coal dust(FCD)in underground mines is an explosion hazard that affects all underground coal mine workers.While this hazard is addressed by the application of rock dust,inadequate rock dusting practices can leave miners exposed to an explosion risk.Researchers at the National Institute for Occupational Safety and Health(NIOSH)have focused on developing a water curtain that removes FCD from the airstream,thereby reducing the buildup of FCD in mine airways.In this study,the number and spacing of the active sprays in the water curtain were varied to determine the optimal configuration to obtain peak knockdown efficiency(KE)while minimizing water consumption.展开更多
Based on the statistical data related to water pollution in recent years, this paper firstly describes in detail the current status of water pollution and water quality in rivers, lakes, reservoirs, groundwater and co...Based on the statistical data related to water pollution in recent years, this paper firstly describes in detail the current status of water pollution and water quality in rivers, lakes, reservoirs, groundwater and coastal waters in China, then makes a comprehensive analysis on future trends of water pollution in China. The authors hold that the economic power, technology level and management level have determinative influences on the current status and future trends of water pollution. At last, this paper discusses briefly the policies and measures for preventing and controlling water pollution in the light of the national conditions.展开更多
Most of developing countries suffer from decreasing and poor quality of drinking water which led to emergence of many dangerous diseases. In addition, there isn’t any methodology followed to predict and disinfect dri...Most of developing countries suffer from decreasing and poor quality of drinking water which led to emergence of many dangerous diseases. In addition, there isn’t any methodology followed to predict and disinfect drinking water by using advanced software program. Maintaining water quality in the water distribution system has become a prominent issue in the study of the water network. Residual chlorine concentration is the indicator to ensure the quality of water in the water network because it eliminates contaminants in the distribution network beginning of the treatment plant down to the consumer. In collaboration with Alexandria (Egypt) Water Company, samples were taken from El-NOZHA water plant station and El-HADARA water distribution network to know the free residual chlorine. In this paper, WaterCAD software has been used to make hydraulic analysis and calibration of residual chlorine in water distribution network to know the ideal chlorine dose that should be added at the water treatment plant and to know the areas of strength and weakness in the concentration of free residual chlorine in the water distribution network. In addition different scenarios have been found to know the free residual chlorine at the weakness areas after injecting chlorine in some junctions and the impact of a fire case or breaking in the water pipe distribution network on the residual chlorine. Results showed ensuring in the water quality in the distribution network by adding chlorine dose in water less than the existing dose which has been added in the El-NOZHA water treatment plant. It is possible to maintain the percentage of free residual chlorine concentration at different locations without relying on adding chlorine only in water treatment plant by injecting low percentage of chlorine dose in the junctions.展开更多
文摘To review the preventive approaches for recurrence after curative resection of hepatic metastases from colorectal carcinoma, we have summarized all available publications reporting randomized control trials (RCTs) covered in PubMed. The treatment approaches presented above include adjuvant intrahepatic arterial infusion chemotherapy, systemic chemotherapy, neoadjuvant chemotherapy, and immunotherapy. Although no standard treatment has been established, several approaches present promising results, which are both effective and tolerable in post-hepatectomy patients. Intrahepatic arterial infusion chemotherapy should be regarded as effective and tolerable and it increases overall survival (OS) and disease free survival (DFS) of patients, while 5-fluorouracil-based systemic chemotherapy has not shown any significant survival benefit. Fortunately chemotherapy combined with hepatic arterial infusion and intravenous infusion has shown OS and DFS benefit in many researches. Few neoadjuvant RCT studies have been conducted to evaluate its effect on prolonging survivals although many retrospective studies and case reports are published in which unresectable colorectal liver metastases are downstaged and made resectable with neoadjuvant chemotherapy. Liver resection supplemented with immunotherapy is associated with optimal results; however, it is also questioned by others. In conclusion, several adjuvant approaches have been studied for their efficacy on recurrence after hepatectomy for liver metastases from colorectal cancer (CRC), but multi-centric RCT is still needed for further evaluation on their efficacy and systemic or local toxicities. In addition, new adjuvant treatment should be investigated to provide more effective and tolerable methods for the patients with resectable hepatic metastases from CRC.
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.
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 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At the present stage, the social economy in China has developed by leaps and bounds. China's pig industry has been well developed un-der the background of this era. However, the number of pig diseases increases due to the influence of many factors, and highly pathogenic porcine reproductive and respiratory syndrome(HP-PRRS) is one of the very common diseases, causing growing mortality rate of pigs. The disease increases the economic loss of pig industry to a large extent, and brings difficulties in prevention and control of pig diseases. The staff must analyze and sum-marize the basic characteristics of pig diseases, and combine some practical problems in prevention and control of pig disease to find effective mea-sures. The scope and scale of pig production in different parts of China have been continuously expanded under the background of further develop-ment of pig industry in the new era. But for pig production, pig disease has been a problem that delays its further development. Related personnel must analyze and summarize the status quo of HP-PRRS, to find effective prevention measures and strategy.
文摘[ Objective ] The aim was to study the influence of filamentous algae on the process of water ecological purification. [ Method ] The occurrence mechanism of filamentous algae and its ecological system were summarized and analyzed. Considering the ecological purification in north- ern Jiangsu, the occurrence and prevention of filamentous algae in water, the method to prevent filamentous algae in polluted water was discussed. [ Result] The results showed that by measures of improving planting density, regular harvesting, and water flow state control before the filamentous algae blooming period, together with improving local pH value, light interference and ecological control during the blooming period, can effectively control the filamentous algae blooming. [ Condusion] The study of the happening mechanism of filamentous algae provided theoretical references and the technical basis in the work of filamentous algae prevention and control.
基金Supported by the National Natural Science Foundation of China,Science Foundation for Youths ( 41001165,40901133,30901163)
文摘The black soil region of Northeast China is one of the most important food production bases and commodity grain bases in China. However, the continual loss and degradation of precious black soil resources has led to direct threats to national food security and regional sustainable development. Therefore, it is necessary to summarize integrated prevention and control experience of small watersheds in black soil region of Northeast China. Tongshuang small watershed, a typical watershed in rolling hills of typical black soil areas in Northeast China, is selected as the study area. Based on nearly 50 years' experience in prevention and control of soil and water loss, the structures and overall benefits of an integrated prevention and control system for soil and water loss are investigated. Then, the 'three defense lines' tri-dimensional protection system with reasonable allocation of different types of soil and water control measures from the hill top to gully is systematically analyzed. The first line on the top hill can weaken and block uphill runoff and sediment, hold water resources and improve soil property. The second line on the hill can truncate slope length, slow down the runoff velocity and reduce erosion energy. The third line in the gully is mainly composed of waterfall engineering, which can inhibit soil erosion and restore land resources. The 'three defense lines' system is feasible for soil and water loss control of small watersheds in the typical black soil region of Northeast China. Through the application of the in Tongshuang small watershed, There are effective improvements in ecological conditions in Tongshuang small watershed after the application of 'three defense lines' soil and water control system. Moreover, the integrated treatment paradigm for soil and water loss in typical black soil region is compared with that in loess region. The results of this study could offer references and experiences for other small watersheds in typical black soil region of Northeast China.
文摘Background: Novel coronavirus pneumonia (NCP) and osteoporotic vertebral compression fractures (OVCF) are the high incidences of diseases in the elderly. During the epidemic period, if not treated in time, the complications are high and the mortality is high. If we do not pay attention to infection prevention and control in pre-hospital emergency care, it will lead to the first time infection of medical staff and in-hospital cross infection in emergency outpatient receiving area. The correct consideration of both and the establishment of perfect pre-hospital emergency treatment and infection prevention and control synchronous strategy is an important premise to ensure the stable, orderly and safe medical treatment. Objective: To explore the effect of synchronous implementation of pre-hospital emergency care, nursing and infection pre-vention and control for senile OVCF during the epidemic. In order to improve the efficiency of pre-hospital emergency care and prevent the spread of infection. Method: A total of 92 elderly patients with OVCF who received pre-hospital treatment in 18 hospitals in Zhangjiakou City during the epidemic prevention and control period from January 2020 to November 2022 and met the inclusion criteria were selected as research objects, including 24 males and 68 females, aged 65 - 82 (74.2 ± 2.2) years. All patients were associated with concomitant injuries and underlying diseases. All patients in this group underwent predictive pre-hospital rescue and infection prevention and control procedures. Results: All the 92 elderly patients with OVCF received timely pre-hospital treatment during the epidemic period, and no aggravation occurred of the 92 patients, 35 were in the high risk area, 10 were in the medium risk area, and 47 were in the low risk area. Exclude OVCF for NCP Patients were treated according to the conventional diagnosis and treatment principles. Suspected and confirmed cases are transferred to designated surgical hospitals for treatment. All patients were followed up 3 months, 6 months and 12 months after treatment. There was no death rate, high satisfaction of pre-hospital first aid, high diagnostic accuracy, and good curative effect. None of the rescue personnel had any infection rate, and no hospital infection transmission and nosocomial cross infection occurred. Conclusion: It is the first step to safely treat patients and prevent cross infection to establish a perfect synchronous strategy of pre-hospital first aid and infection prevention and control.
基金the National Program on Key Basic Research Project of China(973 Program,2011CB505405)the National Natural Science Foundation of China(81730112).
文摘Background:A growing number of randomized controlled trials(RCTs)have explored the significance of adjusting constitution for preventive treatment of disease in traditional Chinese medicine(TCM).In this study,we sought to comprehensively analyze the characteristics of these RCTs.Methods:All RCTs related to constitutional adjustment and preventive treatment of disease were included in the study.Literature was screened searching seven databases,including Pubmed,Web of Science,Embase,SinoMed,CNKI,Chongqing VIP,and Wangfang Database,from inception to December 2018.Data pertaining to bibliometrics,participants,and interventions were extracted and analyzed.Results:Two hundred and forty papers were published between 2007 and 2018,involving 240 RCTs with 55977 total participants.Sample size in these RCTs ranged from 30 to 7800.Among them,59 RCTs addressed disease prevention prior to onset involving 11 healthy states of participants,mainly for general health or sub-health population(40.68%)using health care and non-drug therapy.In control the development of existing disease(n Z 174),59 diseases were involved.Based on the number of RCTs and sample sizes,diseases including type 2 diabetes mellitus,primary hypertension,nonalcoholic fatty liver disease,and hyperlipoproteinemia accounted for 51.15%of the total patients studied.Drug therapy as an intervention was frequently used.In preventing recurrence after recovery(n Z 7),over 4 kinds of health status in participants were involved.Drug therapy combined with health care was mostly used.Most RCTs reported positive outcomes,with only one reporting negative findings(1/240).Conclusion:The number of RCTs of constitutional adjustment on preventive treatment of disease has gradually increased since 2012.Participants and intervention measures from the above-mentioned types of RCTs exhibit their own characteristics.Future systematic reviews or meta-analyses on constitutional adjustment for preventive treatment of disease are warranted.
基金Supported by the Comprehensive Treatment Technology Research and Development for Greenhouse Strawberry Successive Cropping Obstacles,the Agricultural Science and Technology Support Program of Jurong City(NY2016745091)the Integrated Demonstration of Green Control Technologies for Strawberry Pests and Diseases,the Demonstration and Promotion Project of Shanghai Municipal Agricultural Commission[Hunongketui Zi(2015)No.2-7]
文摘The aim was to develop green strawberry varieties,control soil-borne diseases from facility strawberry continuous cropping,improve the safety and quality of strawberries and promote the healthy and stable development of the strawberry industry. Based on the production practices in recent years,we summarized the physical-biological collaborative prevention and control technology for the disease of facility strawberry continuous cropping facilities,established the technical goals,the main types of soil-borne diseases,and the physical-biological collaborative control prevention and control technologies,mainly including the specific methods and technical points of solar high temperature disinfection technology and biological bacterial fertilizer( agent) treatment technology.
基金Supported by National Natural Science Foundation of China(51991361,52074327)Major Engineering Technology Field Test Project of CNPC(2020F-45)。
文摘By summarizing the composition,classification,and performance characterization of functional adhesive materials,the adhesion mechanisms of functional adhesive materials,such as adsorption/surface reaction,diffusion,mechanical interlocking,and electrostatic adsorption,are expounded.The research status of these materials in oil and gas drilling and production engineering field such as lost circulation prevention/control,wellbore stabilization,hydraulic fracturing,and profile control and water plugging,and their application challenges and prospects in oil and gas drilling and production are introduced comprehensively.According to the applications of functional adhesive materials in the field of oil and gas drilling and production at this stage,the key research directions of functional adhesive materials in the area of oil and gas drilling and production are proposed:(1)blending and modifying thermoplastic resins or designing curable thermoplastic resins to improve the bonding performance and pressure bearing capacity of adhesive lost circulation materials;(2)introducing low-cost adhesive groups and positive charge structures into polymers to reduce the cost of wellbore strengthening agents and improve their adhesion performance on the wellbore;(3)introducing thermally reversible covalent bond into thermosetting resin to prevent backflow of proppant and improve the compressive strength of adhesive proppant;(4)introducing thermally reversible covalent bonds into thermoplastic polymers to improve the temperature resistance,salt-resistance and water shutoff performance of adhesive water shutoff agents.
基金supported by the National Natural Science Foundation of China (No.41902154,No.51674209No.51604236)+3 种基金the Sichuan Youth Science and Technology Innovation Research Team Project (No.2021JDTDO017)the Sichuan Province Science and Technology Innovation Miaozi Engineering Cultivation Project (No.2021100)the China Scholarship Council (No.202109225004)。
文摘Shale gas reservoirs are unconventional tight gas reservoirs,in which horizontal wells and hydraulic fracturing are required to achieve commercial development.The fracture networks created by hydraulic fracturing can increase the drainage area extensively to enhance shale gas recovery.However,large volumes of fracturing fluid that is difficult to flow back to the surface and remained in the shale formation,will inevitably lead to damages of the shale formations and limit the effectiveness of stimulation.Supercritical water(SCW)treatment after hydraulic fracturing is a new method to enhance shale gas recovery by using appropriate heat treatment methods to the specific formation to convert the retained fracturing fluid into a supercritical state(at temperatures in excess of 373.946°C and pressures in excess of 22.064 MPa).An experiment was conducted to simulate the reaction between shale and SCW,and the capacity of SCW treatment to enhance the permeability of the shale was evaluated by measuring the response of the shale porosity and permeability on SCW treatment.The experimental results show that the shale porosity and permeability increase by 213.43%and 2198.37%,respectively.The pore structure alteration and permeability enhancement of the shale matrix were determined by analyzing the changes in pore structure and mineral composition after SCW treatment.The mechanisms that affect pore structure and mineral composition include oxidative catalysis decomposition of organic matters and reducing minerals,acid-catalyzed decomposition of carbonate minerals and feldspar minerals,hydrothermal catalysis induced fracture extension and cementation weakening induced fracture extension.SCW treatment converts harm into a benefit by reducing the intrusion of harmful substances into the shale formation,which will broaden the scope and scale of shale formation stimulation.
文摘Man made activities are changing environment of our planet earth.Various methods are used to reduce the environmental pollution.In this paper the methods of air/water/soil pollution mitigation/reduction using electromagnetic fields is discussed.Air/water/soil contains ions and the energy transfer for living organisms takes place by ion exchange processes.Ions are affected by electric/magnetic fields.Many investigators
文摘The shortage of water resources is severe in Beijing. The shortage of eco-environmental water and the sewage discharge over the environmental capacity are main bottlenecks that restrict the improvement of water environment. The reuse of wastewater could not only reduce the discharge of pollutants,but it could also increase the consumption of eco-environmental water. Therefore the reuse of wastewater is an important approach to improve the water environmental quality. Combined with the formulation process of Regulations of Beijing on Prevention and Control of Water Pollution,the current situations of prevention and control of water pollution in Beijing,the discharge of pollutant,water environmental quality,the population and economic development and water resources and so on were analyzed. And the bottlenecks that restricted the improvement of water environmental quality were found. And the necessity of solving the control of water pollution by reusing the wastewater and ensuring the consumption of eco-environmental water was analyzed from the perspective of the control of water pollution. And some legislative countermeasures were put forward,which provided new ideas for solving the problem of the prevention and control of water pollution and improving the water environmental quality. It was of important reference values for local governments( especially water-deficient regions) to make relative polices or plans of water pollution control and water environmental protection.
文摘Water supply project of drawing from the Songhua River in central cities of Jilin is taken as research object.On the basis of analyzing project characteristics and natural conditions of the project area,site selection of waste slag yard of water diversion project and design of water and soil conservation measures are discussed.Rationality of site selection of waste slag yard and pertinence of prevention and control measures of water and soil loss in waste slag yard are analyzed,and comprehensive utilization of waste slag in large-scale production and construction projects is explored.
文摘Hemp sesbania (Sesbania exaltata) plants (>30 cm tall) sprayed with hot water (45°C – 95°C), followed by spray applications of fungal spores of Colletotrichum truncatum (CT) at 1.0 × 107 spores/ml-1 and 22°C – 25°C, suspended either in: 0.2% Silwet L-77 surfactant (SW);unrefined corn oil (CO)/distilled water (1:1, v:v);or 0.2% SW in CO were controlled by 80% - 95%, 12 days after treatment (DAT) under greenhouse conditions. These treatments also reduced dry weight accumulation of this weed. Plants treated with hot water without CT were also injured at temperatures ≥35°C (5% mortality), and 60% mortality at 95°C. Artificial dew treatments (25°C, 12 h), imposed on plants after the treatment protocols above, had little or no effect on weed mortality or dry weight reduction compared to treated plants without dew. Under field conditions, 85% control of hemp sesbania was achieved 12 - 15 DAT when a pre-treatment with hot water (65°C) was followed immediately with a CT application at the spore concentration as described above. Plants in field tests treated with CT without a hot water treatment were visually unaffected, with no mortality or plant biomass reductions recorded 15 DAT. These results suggest that use of hot water may be an important tool for improving the infectivity and bioherbicidal potential of some plant pathogens.
文摘Accumulation of float coal dust(FCD)in underground mines is an explosion hazard that affects all underground coal mine workers.While this hazard is addressed by the application of rock dust,inadequate rock dusting practices can leave miners exposed to an explosion risk.Researchers at the National Institute for Occupational Safety and Health(NIOSH)have focused on developing a water curtain that removes FCD from the airstream,thereby reducing the buildup of FCD in mine airways.In this study,the number and spacing of the active sprays in the water curtain were varied to determine the optimal configuration to obtain peak knockdown efficiency(KE)while minimizing water consumption.
文摘Based on the statistical data related to water pollution in recent years, this paper firstly describes in detail the current status of water pollution and water quality in rivers, lakes, reservoirs, groundwater and coastal waters in China, then makes a comprehensive analysis on future trends of water pollution in China. The authors hold that the economic power, technology level and management level have determinative influences on the current status and future trends of water pollution. At last, this paper discusses briefly the policies and measures for preventing and controlling water pollution in the light of the national conditions.
文摘Most of developing countries suffer from decreasing and poor quality of drinking water which led to emergence of many dangerous diseases. In addition, there isn’t any methodology followed to predict and disinfect drinking water by using advanced software program. Maintaining water quality in the water distribution system has become a prominent issue in the study of the water network. Residual chlorine concentration is the indicator to ensure the quality of water in the water network because it eliminates contaminants in the distribution network beginning of the treatment plant down to the consumer. In collaboration with Alexandria (Egypt) Water Company, samples were taken from El-NOZHA water plant station and El-HADARA water distribution network to know the free residual chlorine. In this paper, WaterCAD software has been used to make hydraulic analysis and calibration of residual chlorine in water distribution network to know the ideal chlorine dose that should be added at the water treatment plant and to know the areas of strength and weakness in the concentration of free residual chlorine in the water distribution network. In addition different scenarios have been found to know the free residual chlorine at the weakness areas after injecting chlorine in some junctions and the impact of a fire case or breaking in the water pipe distribution network on the residual chlorine. Results showed ensuring in the water quality in the distribution network by adding chlorine dose in water less than the existing dose which has been added in the El-NOZHA water treatment plant. It is possible to maintain the percentage of free residual chlorine concentration at different locations without relying on adding chlorine only in water treatment plant by injecting low percentage of chlorine dose in the junctions.