Objective:The aim is to develop and verify the feasibility of an adolescent coping model in seasonal flood-prone areas.This coping model supports mental health nurses'practical application to adolescents in flood-...Objective:The aim is to develop and verify the feasibility of an adolescent coping model in seasonal flood-prone areas.This coping model supports mental health nurses'practical application to adolescents in flood-prone areas.Methods:We developed the adolescent coping model based on the processes established in three integrated theories:self-care management for vulnerable populations,coping approaches,and coping with disaster.We conducted semi-structured interviews with 15 participants to explore their perspectives and experiences with flood disasters.We used purposeful sampling for maximum diversity.Data were collected through face-to-face,in-depth interviews.Data were transcribed verbatim,followed by qualitative content analysis.The coping model of adolescents in flood-prone areas was analyzed qualitatively and inductively from the viewpoint of acceptability.Results:The following five categories were identified:(1)coping process post-disaster;(2)coping approach;(3)community power;(4)vulnerability;and(5)self-potential.These domains formed a model for coping model adolescents in seasonal flood-prone areas.Accordingly,our findings showed that the model could be practical for mental health community nursing.Conclusions:Mental health nurses can use the coping model for disaster mental health nursing in adolescents in flood-prone areas.The application of this model will help adolescents increase self-efficacy.展开更多
Controlled,guided munitions can reduce dispersion in the shot,while providing the capability of engaging both stationary and maneuvering targets.The Netherlands Organisation for Applied Scientific Research has develop...Controlled,guided munitions can reduce dispersion in the shot,while providing the capability of engaging both stationary and maneuvering targets.The Netherlands Organisation for Applied Scientific Research has developed a fin-less control technology called Stagnation Pressure Reaction Control(SPRC)that takes stagnation pressure air and directs it sideways to control non-spinning projectiles.In a previous study,this technology was demonstrated at Mach 2 wind-tunnel conditions to achieve up to 1.5°controllable angle of incidence for a non-spinning,aerodynamically unstable projectile-like test object.In an operational scenario,the decelerating projectile will experience a decline in control force while the simultaneous forward shift of the center of pressure increases the need for control force.Furthermore,angles of incidence exceeding 1.5°will be experienced under realistic flight conditions,especially against maneuvering targets.This work addresses these challenges and presents an operational feasibility study for a practical application of SPRC in a non-spinning mid-caliber gun-launched projectile,using experiment data on control latency and force of the earlier study.It illustrates the combined effect of the control-and stability dynamics and underlines the potential of an SPRC projectile as a precisionoperation ammunition.This research revealed that SPRC technology can stabilize and control the hypothesized projectile in a direct fire scenario against stationary and maneuvering targets.展开更多
The energy industry faces a significant challenge in extracting natural gas from offshore natural gas hydrate(NGH)reservoirs,primarily due to the low productivity of wells and the high operational costs involved.The p...The energy industry faces a significant challenge in extracting natural gas from offshore natural gas hydrate(NGH)reservoirs,primarily due to the low productivity of wells and the high operational costs involved.The present study offers an assessment of the feasibility of utilizing geothermal energy to augment the production of natural gas from offshore gas hydrate reservoirs through the implementation of the methane-CO_(2)swapping technique.The present study expands the research scope of the authors beyond their previous publication,which exclusively examined the generation of methane from marine gas hydrates.Specifically,the current investigation explores the feasibility of utilizing the void spaces created by the extracted methane in the hydrate reservoir for carbon dioxide storage.Analytical models were employed to forecast the heat transfer from a geothermal zone to an NGH reservoir.A study was conducted utilizing data obtained from a reservoir situated in the Shenhu region of the Northern South China Sea.The findings of the model indicate that the implementation of geothermal heating can lead to a substantial enhancement in the productivity of wells located in heated reservoirs during CO_(2)swapping procedures.The non-linear relationship between the temperature of the heated reservoir and the rate of fold increase has been observed.It is anticipated that the fold of increase will surpass 5 when the gas hydrate reservoir undergoes a temperature rise from 6℃ to 16℃.The mathematical models utilized in this study did not incorporate the impact of heat convection resulting from CO_(2)flow into the gas reservoir.This factor has the potential to enhance well productivity.The mathematical models’deviation assumptions may cause over-prediction of well productivity in geothermal-stimulated reservoirs.Additional research is required to examine the impacts of temperature drawdown,heat convection resulting from depressurization,heat-induced gas pressure increment,and the presence of free gas in the formation containing hydrates.The process of CH4-CO_(2)swapping,which has been investigated,involves the utilization of geothermal stimulation.This method is highly encouraging as it enables the efficient injection of CO_(2)into gas hydrate reservoirs,resulting in the permanent sequestration of CO_(2)in a solid state.Additional research is warranted to examine the rate of mass transfer of CO_(2)within reservoirs of gas hydrates.展开更多
Field SZ36-1 is a water-flooded heavy oil reservoir with high porosity and unconsolidated sand. The recovery rate is low so that it becomes a challenge for production. Time-lapse seismic data is studied to improve the...Field SZ36-1 is a water-flooded heavy oil reservoir with high porosity and unconsolidated sand. The recovery rate is low so that it becomes a challenge for production. Time-lapse seismic data is studied to improve the oil recovery for this field, This feasibility study analyzes the possible time-lapse seismic attribute spatial distribution using dynamic data and the reservoir model to determine the optimum time to acquire a new seismic survey. Based on the study, it is found that the time-lapse seismic response for this unconsolidated sand has a strong signature due to solution gas when the reservoir pressure is below the bubble point. This indicates that acquiring a new survey after 10 years of production is appropriate for a time-lapse seismic application.展开更多
The Taihang Mountains area is an area in North China where serious mudflow hazards take place frequently. The hazards often obstrust traffic and make it difficult to carry out conventional ground investigations of the...The Taihang Mountains area is an area in North China where serious mudflow hazards take place frequently. The hazards often obstrust traffic and make it difficult to carry out conventional ground investigations of the mudflow hazards. This paper introduces the feasibility study of mudflow hazards by using Landsat-5TM data. The study has achieved a great success through adopting both the faint spectral enhancement technique for mudflow fans (or other depositional areas) and comprehensive study of the environmental background of pregnant mudflows. Thus, remote sensing as a fast, convenient, low-cost and effective technical method can be used to recognise the situation of mudflow hazards so that effective rescue can be provided.展开更多
Yima Coal Corporation is considering to adopt highwall mining method withauger machine to recover coal from north surface pit that has reached final highwall position. Themajor geomechanical issues associated with aug...Yima Coal Corporation is considering to adopt highwall mining method withauger machine to recover coal from north surface pit that has reached final highwall position. Themajor geomechanical issues associated with auger mining are highwall and pillar stability. Based onthe field investigation and laboratory test results of mechanical parameters, numerical modeling iscarried out to assess the stability of highwall and pillar. Field measurements of highwalldeformation have been used to validate and ensure the confidence for the development of realisticmodels. The results of numerical modeling show that the mining method is feasible for mining theseam of 10 m thickness in north surface coal mine.展开更多
Jinchuan nickel mine is the largest nickel mine in China. Cut-and-fill mining method with high density cementing materials is used in the mine. The original mining design divided the mining operation into two steps. T...Jinchuan nickel mine is the largest nickel mine in China. Cut-and-fill mining method with high density cementing materials is used in the mine. The original mining design divided the mining operation into two steps. The first step stopped the mining rooms and the second step stopped the pillars. Because the two-step method made big trouble for finally mining pillars and strongly limited the mining speed and production, it was successfully changed to a continuous cut-and-fill method without pillars. However, the mining operation in the mine has been down to 800 m and the mining condition is getting worse and more complicated. Through systematical field investigations and 3-D FEM analysis, it is proved that the mining method without pillars is feasible for mining deeper orebodies in Jinchuan nickel mine.展开更多
Some energy experts believe that solar energy photovoltaic power generation is hopeful to be applied in a large amount and possesses a certain proportion in the structure of energy in the future. In this paper, based ...Some energy experts believe that solar energy photovoltaic power generation is hopeful to be applied in a large amount and possesses a certain proportion in the structure of energy in the future. In this paper, based on the forecasting of electric load demand and energy structure of power generation in the middle of 21 century, the pictures of VLS-PV power genera- tion is composed, the operation characteristic of VLS-PV power generation and the adaptability of electric power grid for it is analyzed, the ways for transmitting large amount of PV power and the economic and technical bottlenecks for applying VLS-PV power generation are discussed. Finally, the steps and suggestions for developing VLS-PV power generation and its electric power system in China are proposed.展开更多
The Toroidal Field (TF) coil case of the HT-7U superconducting tokamak device is made of austenitic stainless steel 316LN and is designed to operate at cryogenic temperature (4 K). 316LN can retain high strength and f...The Toroidal Field (TF) coil case of the HT-7U superconducting tokamak device is made of austenitic stainless steel 316LN and is designed to operate at cryogenic temperature (4 K). 316LN can retain high strength and fracture toughness at 4 K. Feasibility study on technical process of welding has been experimentally considered as a hopeful joint method for suppression of post-welding deformation and reduction of over-heating. Meanwhile the final range of stress intensity and the stress intensity factor (K) for pre-cracks of welding structure have been determined by using J-integral. These related results are optimistic and have shown that there's no problem in strength and fracture toughness at the vicinity of the pre-crack tip. This paper introduces the welding structure of TF coil case in detail.展开更多
Renewable energy, particularly solar energy, offers a clean and alternative energy source to meet the energy demand for sustainable development in the world. Due to its profitability and viability, PV net-metering sch...Renewable energy, particularly solar energy, offers a clean and alternative energy source to meet the energy demand for sustainable development in the world. Due to its profitability and viability, PV net-metering scheme has been adopted in many countries. The feasibility of implementation PV rooftop system with net metering in residential, commercial, governmental and industrial sectors in Iraq is demonstrated in this study. A financial model has been developed to investigate the feasibility parameters <i>NPV</i>, <i>IRR</i> and annual savings of 24 kWp PV system. The results showed that increasing the capacity of the PV system in residential and commercial buildings will lead to a profitable investment return and the breakeven point that may make the PV net-metering projects feasible is very close to the tariff applied for the commercial sector (10.29 $c/kWh). In the governmental sector, the tariff needs to </span><span style="font-family:Verdana;">increase by 35.1% to reach breakeven. However, for such net-metering scheme</span><span style="font-family:Verdana;"> to be attractive and feasible on a wide scale, it is crucial to back it with financial support through soft loans and grants.展开更多
The differential pricing for peak hours encourages industrial consumers to look for independent power supplies for the period from 19 to 22 hours. This paper presents a study to identify the optimal solution for a rec...The differential pricing for peak hours encourages industrial consumers to look for independent power supplies for the period from 19 to 22 hours. This paper presents a study to identify the optimal solution for a recycled paper mill that also intends to work in that period. The factory is located in Rio Grande do Sul, in southern Brazil, and considers the use of a diesel gen set, a micro hydro power plant and possibly PV modules. Two micro hydro power plants were considered in the study, an old plant to be renewed and another to be fully implemented. The software Homer was used as a tool to determine the most feasible combination of components considered in the study. The sale of surplus power to the energy system appears as a key to viability of alternatives that are not based solely on diesel generators. The optimal solution consists of a combination of diesel generators and micro hydro power plant, in one case, and only on hydroelectric power plant in another, with a significant penetration of PV modules if its cost is reduced to 12% of the current price, selling an amount of energy equal to that which is bought. The annual water availability in one of the sites requires diesel supplement, while the other, more abundant, this supplement is not necessary.展开更多
The aim of this work is double. Firstly, we want to stress out that investing in renewable energies in 2009 in Spain was a profitable activity. This question will be answered studying the possibilities of expanding "...The aim of this work is double. Firstly, we want to stress out that investing in renewable energies in 2009 in Spain was a profitable activity. This question will be answered studying the possibilities of expanding "Sierra de Tineo" wind farm in the Principality of Asturias (location, wind resource, data analysis, simulation, legal standards and economic and sensitivity study of the investment), and for that, data from the year 2009 have been used. And secondly, the goal is to set the bases for a future paper where the current situation of Spain (within the renewable framework), will be compared with the 2009 scenario.展开更多
In the field of large-capacity accelerator construction, there are two world-wide trends now evident in high-energy physicists: one is to build up high-energy ones such as the LHC (Large Hadron Collider) developed by ...In the field of large-capacity accelerator construction, there are two world-wide trends now evident in high-energy physicists: one is to build up high-energy ones such as the LHC (Large Hadron Collider) developed by Conseil Européen pour la Recherches Nucleaires (CERN) and the other features high precision, including β-factories in the US and Japan and the φ-factory and τ-factory展开更多
The feasibility study of the Beijing Tau-Charm Factory(BTCF), approved by the Chinese government to have been completing from February of 1995 to the end of 1996, has been carried out successfully by the Institute of ...The feasibility study of the Beijing Tau-Charm Factory(BTCF), approved by the Chinese government to have been completing from February of 1995 to the end of 1996, has been carried out successfully by the Institute of High-Energy Physics (IHEP) under the CAS.Also this is a cooperative project shared by seven Chinese institutions of Peking University,the CAS Institute of Theoretical Physics,Nanjing University,Shandong University,Shanghai Jiaotong University, Qinghua University and the CAS-affiliated University of S&T of China. The main tasks of this study are:展开更多
Objective:The size and morphology of the right ventricular outflow tract(RVOT)in patients suffering from long-term pulmonary regurgitation(PR)after native RVOT(NRVOT)reconstruction are important factors affecting the ...Objective:The size and morphology of the right ventricular outflow tract(RVOT)in patients suffering from long-term pulmonary regurgitation(PR)after native RVOT(NRVOT)reconstruction are important factors affecting the feasibility,safety,and effectiveness of transcatheter pulmonary valve replacement.The purpose of this study was to evaluate the feasibility,safety,and effectiveness of a transthoracic Salus valve(Balance Medical Technology Co.,Ltd,Beijing,China)in patients with moderate-to-severe PR after NRVOT reconstruction.Methods:Patients with moderate-to-severe PR after NRVOT reconstruction were selected between June 2021 and November 2021 at Beijing Anzhen Hospital.Demographic data as well as preoperative,intraoperative,and follow-up data were reviewed.Results:Ten patients with moderate-to-severe PR after NRVOT reconstruction underwent physical examination,transthoracic echocardiography,and cardiovascular magnetic resonance imaging.Seven patients were selected for transthoracic Salus valve replacement.Six patients underwent implantation of the Salus valve successfully.One valve migrated and was embolized during recovery of the delivery device;the Salus valve was surgically explanted and sutured to the inner wall of the main pulmonary artery.At a mean follow-up of(5.5±1.1)months,dysfunction or migration of the Salus valve embolism was not observed.Conclusions:This early feasibility study demonstrates the feasibility,safety,and effectiveness of transthoracic implantation of a Salus valve in patients with moderate-to-severe PR after NRVOT reconstruction.The short-term effectiveness is clear,medium and long-term effectiveness requires longer follow-up.展开更多
Fire disasters and the deterioration of tunnel structures are major concerns for tunnel operation and maintenance.Traditional wired monitoring systems have many drawbacks in terms of installation time,overall cost,and...Fire disasters and the deterioration of tunnel structures are major concerns for tunnel operation and maintenance.Traditional wired monitoring systems have many drawbacks in terms of installation time,overall cost,and flexibility in tunnel environments.In recent years,there has been growing interest in the use of wireless sensor networks(WSNs)for the monitoring of various structural monitoring applications.This paper evaluated the feasibility of applying a WSN in the monitoring of tunnels.The monitoring requirements of tunnels under explosion and combustion fire scenarios are analyzed using numerical simulation,and the maximum possible distance for temperature sensors is derived.The displacement monitoring of tunnels using an inclinometer is investigated.It is recommended that the inclinometer should be installed in the 1/4 span of the tunnel structure.The maximum wireless transmission distances in both outdoor and tunnel environments were examined.The influences of surface materials and sensor node locations on the data transmission distance in tunnel environments were also investigated.The experimental results show that the data loss in tunnel environments is approximately three times that in outdoor environments.Surface material has a considerable influence on the transmission distance of radio signals.The distance is 25~28 m for a raw concrete surface,20 m for a brick surface,and 36 m for a terrazzo surface.The transmission distances along the middle of quarter points are approximately 0.9D(D is the transmission distance in the center of the tunnel),and the relative error is less than±3%.The transmission distances at different locations along the bottom exhibit significant differences,decreasing from the middle to the comer point,with distances of approximately 0.8D at the quarter points and minimum distances of approximately 0.55D at the comer points.展开更多
文摘Objective:The aim is to develop and verify the feasibility of an adolescent coping model in seasonal flood-prone areas.This coping model supports mental health nurses'practical application to adolescents in flood-prone areas.Methods:We developed the adolescent coping model based on the processes established in three integrated theories:self-care management for vulnerable populations,coping approaches,and coping with disaster.We conducted semi-structured interviews with 15 participants to explore their perspectives and experiences with flood disasters.We used purposeful sampling for maximum diversity.Data were collected through face-to-face,in-depth interviews.Data were transcribed verbatim,followed by qualitative content analysis.The coping model of adolescents in flood-prone areas was analyzed qualitatively and inductively from the viewpoint of acceptability.Results:The following five categories were identified:(1)coping process post-disaster;(2)coping approach;(3)community power;(4)vulnerability;and(5)self-potential.These domains formed a model for coping model adolescents in seasonal flood-prone areas.Accordingly,our findings showed that the model could be practical for mental health community nursing.Conclusions:Mental health nurses can use the coping model for disaster mental health nursing in adolescents in flood-prone areas.The application of this model will help adolescents increase self-efficacy.
文摘Controlled,guided munitions can reduce dispersion in the shot,while providing the capability of engaging both stationary and maneuvering targets.The Netherlands Organisation for Applied Scientific Research has developed a fin-less control technology called Stagnation Pressure Reaction Control(SPRC)that takes stagnation pressure air and directs it sideways to control non-spinning projectiles.In a previous study,this technology was demonstrated at Mach 2 wind-tunnel conditions to achieve up to 1.5°controllable angle of incidence for a non-spinning,aerodynamically unstable projectile-like test object.In an operational scenario,the decelerating projectile will experience a decline in control force while the simultaneous forward shift of the center of pressure increases the need for control force.Furthermore,angles of incidence exceeding 1.5°will be experienced under realistic flight conditions,especially against maneuvering targets.This work addresses these challenges and presents an operational feasibility study for a practical application of SPRC in a non-spinning mid-caliber gun-launched projectile,using experiment data on control latency and force of the earlier study.It illustrates the combined effect of the control-and stability dynamics and underlines the potential of an SPRC projectile as a precisionoperation ammunition.This research revealed that SPRC technology can stabilize and control the hypothesized projectile in a direct fire scenario against stationary and maneuvering targets.
基金funding the project“Safe,Sustainable,and Resilient Development of Offshore Reservoirs and Natural Gas Upgrading through Innovative Science and Technology:Gulf of Mexico–Mediterranean,”through Contract No.EC-19 Fossil Energy。
文摘The energy industry faces a significant challenge in extracting natural gas from offshore natural gas hydrate(NGH)reservoirs,primarily due to the low productivity of wells and the high operational costs involved.The present study offers an assessment of the feasibility of utilizing geothermal energy to augment the production of natural gas from offshore gas hydrate reservoirs through the implementation of the methane-CO_(2)swapping technique.The present study expands the research scope of the authors beyond their previous publication,which exclusively examined the generation of methane from marine gas hydrates.Specifically,the current investigation explores the feasibility of utilizing the void spaces created by the extracted methane in the hydrate reservoir for carbon dioxide storage.Analytical models were employed to forecast the heat transfer from a geothermal zone to an NGH reservoir.A study was conducted utilizing data obtained from a reservoir situated in the Shenhu region of the Northern South China Sea.The findings of the model indicate that the implementation of geothermal heating can lead to a substantial enhancement in the productivity of wells located in heated reservoirs during CO_(2)swapping procedures.The non-linear relationship between the temperature of the heated reservoir and the rate of fold increase has been observed.It is anticipated that the fold of increase will surpass 5 when the gas hydrate reservoir undergoes a temperature rise from 6℃ to 16℃.The mathematical models utilized in this study did not incorporate the impact of heat convection resulting from CO_(2)flow into the gas reservoir.This factor has the potential to enhance well productivity.The mathematical models’deviation assumptions may cause over-prediction of well productivity in geothermal-stimulated reservoirs.Additional research is required to examine the impacts of temperature drawdown,heat convection resulting from depressurization,heat-induced gas pressure increment,and the presence of free gas in the formation containing hydrates.The process of CH4-CO_(2)swapping,which has been investigated,involves the utilization of geothermal stimulation.This method is highly encouraging as it enables the efficient injection of CO_(2)into gas hydrate reservoirs,resulting in the permanent sequestration of CO_(2)in a solid state.Additional research is warranted to examine the rate of mass transfer of CO_(2)within reservoirs of gas hydrates.
文摘Field SZ36-1 is a water-flooded heavy oil reservoir with high porosity and unconsolidated sand. The recovery rate is low so that it becomes a challenge for production. Time-lapse seismic data is studied to improve the oil recovery for this field, This feasibility study analyzes the possible time-lapse seismic attribute spatial distribution using dynamic data and the reservoir model to determine the optimum time to acquire a new seismic survey. Based on the study, it is found that the time-lapse seismic response for this unconsolidated sand has a strong signature due to solution gas when the reservoir pressure is below the bubble point. This indicates that acquiring a new survey after 10 years of production is appropriate for a time-lapse seismic application.
文摘The Taihang Mountains area is an area in North China where serious mudflow hazards take place frequently. The hazards often obstrust traffic and make it difficult to carry out conventional ground investigations of the mudflow hazards. This paper introduces the feasibility study of mudflow hazards by using Landsat-5TM data. The study has achieved a great success through adopting both the faint spectral enhancement technique for mudflow fans (or other depositional areas) and comprehensive study of the environmental background of pregnant mudflows. Thus, remote sensing as a fast, convenient, low-cost and effective technical method can be used to recognise the situation of mudflow hazards so that effective rescue can be provided.
文摘Yima Coal Corporation is considering to adopt highwall mining method withauger machine to recover coal from north surface pit that has reached final highwall position. Themajor geomechanical issues associated with auger mining are highwall and pillar stability. Based onthe field investigation and laboratory test results of mechanical parameters, numerical modeling iscarried out to assess the stability of highwall and pillar. Field measurements of highwalldeformation have been used to validate and ensure the confidence for the development of realisticmodels. The results of numerical modeling show that the mining method is feasible for mining theseam of 10 m thickness in north surface coal mine.
文摘Jinchuan nickel mine is the largest nickel mine in China. Cut-and-fill mining method with high density cementing materials is used in the mine. The original mining design divided the mining operation into two steps. The first step stopped the mining rooms and the second step stopped the pillars. Because the two-step method made big trouble for finally mining pillars and strongly limited the mining speed and production, it was successfully changed to a continuous cut-and-fill method without pillars. However, the mining operation in the mine has been down to 800 m and the mining condition is getting worse and more complicated. Through systematical field investigations and 3-D FEM analysis, it is proved that the mining method without pillars is feasible for mining deeper orebodies in Jinchuan nickel mine.
文摘Some energy experts believe that solar energy photovoltaic power generation is hopeful to be applied in a large amount and possesses a certain proportion in the structure of energy in the future. In this paper, based on the forecasting of electric load demand and energy structure of power generation in the middle of 21 century, the pictures of VLS-PV power genera- tion is composed, the operation characteristic of VLS-PV power generation and the adaptability of electric power grid for it is analyzed, the ways for transmitting large amount of PV power and the economic and technical bottlenecks for applying VLS-PV power generation are discussed. Finally, the steps and suggestions for developing VLS-PV power generation and its electric power system in China are proposed.
文摘The Toroidal Field (TF) coil case of the HT-7U superconducting tokamak device is made of austenitic stainless steel 316LN and is designed to operate at cryogenic temperature (4 K). 316LN can retain high strength and fracture toughness at 4 K. Feasibility study on technical process of welding has been experimentally considered as a hopeful joint method for suppression of post-welding deformation and reduction of over-heating. Meanwhile the final range of stress intensity and the stress intensity factor (K) for pre-cracks of welding structure have been determined by using J-integral. These related results are optimistic and have shown that there's no problem in strength and fracture toughness at the vicinity of the pre-crack tip. This paper introduces the welding structure of TF coil case in detail.
文摘Renewable energy, particularly solar energy, offers a clean and alternative energy source to meet the energy demand for sustainable development in the world. Due to its profitability and viability, PV net-metering scheme has been adopted in many countries. The feasibility of implementation PV rooftop system with net metering in residential, commercial, governmental and industrial sectors in Iraq is demonstrated in this study. A financial model has been developed to investigate the feasibility parameters <i>NPV</i>, <i>IRR</i> and annual savings of 24 kWp PV system. The results showed that increasing the capacity of the PV system in residential and commercial buildings will lead to a profitable investment return and the breakeven point that may make the PV net-metering projects feasible is very close to the tariff applied for the commercial sector (10.29 $c/kWh). In the governmental sector, the tariff needs to </span><span style="font-family:Verdana;">increase by 35.1% to reach breakeven. However, for such net-metering scheme</span><span style="font-family:Verdana;"> to be attractive and feasible on a wide scale, it is crucial to back it with financial support through soft loans and grants.
文摘The differential pricing for peak hours encourages industrial consumers to look for independent power supplies for the period from 19 to 22 hours. This paper presents a study to identify the optimal solution for a recycled paper mill that also intends to work in that period. The factory is located in Rio Grande do Sul, in southern Brazil, and considers the use of a diesel gen set, a micro hydro power plant and possibly PV modules. Two micro hydro power plants were considered in the study, an old plant to be renewed and another to be fully implemented. The software Homer was used as a tool to determine the most feasible combination of components considered in the study. The sale of surplus power to the energy system appears as a key to viability of alternatives that are not based solely on diesel generators. The optimal solution consists of a combination of diesel generators and micro hydro power plant, in one case, and only on hydroelectric power plant in another, with a significant penetration of PV modules if its cost is reduced to 12% of the current price, selling an amount of energy equal to that which is bought. The annual water availability in one of the sites requires diesel supplement, while the other, more abundant, this supplement is not necessary.
文摘The aim of this work is double. Firstly, we want to stress out that investing in renewable energies in 2009 in Spain was a profitable activity. This question will be answered studying the possibilities of expanding "Sierra de Tineo" wind farm in the Principality of Asturias (location, wind resource, data analysis, simulation, legal standards and economic and sensitivity study of the investment), and for that, data from the year 2009 have been used. And secondly, the goal is to set the bases for a future paper where the current situation of Spain (within the renewable framework), will be compared with the 2009 scenario.
文摘In the field of large-capacity accelerator construction, there are two world-wide trends now evident in high-energy physicists: one is to build up high-energy ones such as the LHC (Large Hadron Collider) developed by Conseil Européen pour la Recherches Nucleaires (CERN) and the other features high precision, including β-factories in the US and Japan and the φ-factory and τ-factory
文摘The feasibility study of the Beijing Tau-Charm Factory(BTCF), approved by the Chinese government to have been completing from February of 1995 to the end of 1996, has been carried out successfully by the Institute of High-Energy Physics (IHEP) under the CAS.Also this is a cooperative project shared by seven Chinese institutions of Peking University,the CAS Institute of Theoretical Physics,Nanjing University,Shandong University,Shanghai Jiaotong University, Qinghua University and the CAS-affiliated University of S&T of China. The main tasks of this study are:
基金supported by the National Key Research and Development Program of China(2020YFC1107903).
文摘Objective:The size and morphology of the right ventricular outflow tract(RVOT)in patients suffering from long-term pulmonary regurgitation(PR)after native RVOT(NRVOT)reconstruction are important factors affecting the feasibility,safety,and effectiveness of transcatheter pulmonary valve replacement.The purpose of this study was to evaluate the feasibility,safety,and effectiveness of a transthoracic Salus valve(Balance Medical Technology Co.,Ltd,Beijing,China)in patients with moderate-to-severe PR after NRVOT reconstruction.Methods:Patients with moderate-to-severe PR after NRVOT reconstruction were selected between June 2021 and November 2021 at Beijing Anzhen Hospital.Demographic data as well as preoperative,intraoperative,and follow-up data were reviewed.Results:Ten patients with moderate-to-severe PR after NRVOT reconstruction underwent physical examination,transthoracic echocardiography,and cardiovascular magnetic resonance imaging.Seven patients were selected for transthoracic Salus valve replacement.Six patients underwent implantation of the Salus valve successfully.One valve migrated and was embolized during recovery of the delivery device;the Salus valve was surgically explanted and sutured to the inner wall of the main pulmonary artery.At a mean follow-up of(5.5±1.1)months,dysfunction or migration of the Salus valve embolism was not observed.Conclusions:This early feasibility study demonstrates the feasibility,safety,and effectiveness of transthoracic implantation of a Salus valve in patients with moderate-to-severe PR after NRVOT reconstruction.The short-term effectiveness is clear,medium and long-term effectiveness requires longer follow-up.
基金This research was supported by the National Basic Research Program of China(973 Program:2011CB013800)Changjiang Scholars and Innovative Research Team in University(PCSIRT,IRT1029)and the Fundamental Research Funds for the Central Universities.These financial supports are gratefully acknowledged.
文摘Fire disasters and the deterioration of tunnel structures are major concerns for tunnel operation and maintenance.Traditional wired monitoring systems have many drawbacks in terms of installation time,overall cost,and flexibility in tunnel environments.In recent years,there has been growing interest in the use of wireless sensor networks(WSNs)for the monitoring of various structural monitoring applications.This paper evaluated the feasibility of applying a WSN in the monitoring of tunnels.The monitoring requirements of tunnels under explosion and combustion fire scenarios are analyzed using numerical simulation,and the maximum possible distance for temperature sensors is derived.The displacement monitoring of tunnels using an inclinometer is investigated.It is recommended that the inclinometer should be installed in the 1/4 span of the tunnel structure.The maximum wireless transmission distances in both outdoor and tunnel environments were examined.The influences of surface materials and sensor node locations on the data transmission distance in tunnel environments were also investigated.The experimental results show that the data loss in tunnel environments is approximately three times that in outdoor environments.Surface material has a considerable influence on the transmission distance of radio signals.The distance is 25~28 m for a raw concrete surface,20 m for a brick surface,and 36 m for a terrazzo surface.The transmission distances along the middle of quarter points are approximately 0.9D(D is the transmission distance in the center of the tunnel),and the relative error is less than±3%.The transmission distances at different locations along the bottom exhibit significant differences,decreasing from the middle to the comer point,with distances of approximately 0.8D at the quarter points and minimum distances of approximately 0.55D at the comer points.