Customer segmentation according to load-shape profiles using smart meter data is an increasingly important application to vital the planning and operation of energy systems and to enable citizens’participation in the...Customer segmentation according to load-shape profiles using smart meter data is an increasingly important application to vital the planning and operation of energy systems and to enable citizens’participation in the energy transition.This study proposes an innovative multi-step clustering procedure to segment customers based on load-shape patterns at the daily and intra-daily time horizons.Smart meter data is split between daily and hourly normalized time series to assess monthly,weekly,daily,and hourly seasonality patterns separately.The dimensionality reduction implicit in the splitting allows a direct approach to clustering raw daily energy time series data.The intraday clustering procedure sequentially identifies representative hourly day-unit profiles for each customer and the entire population.For the first time,a step function approach is applied to reduce time series dimensionality.Customer attributes embedded in surveys are employed to build external clustering validation metrics using Cramer’s V correlation factors and to identify statistically significant determinants of load-shape in energy usage.In addition,a time series features engineering approach is used to extract 16 relevant demand flexibility indicators that characterize customers and corresponding clusters along four different axes:available Energy(E),Temporal patterns(T),Consistency(C),and Variability(V).The methodology is implemented on a real-world electricity consumption dataset of 325 Small and Medium-sized Enterprise(SME)customers,identifying 4 daily and 6 hourly easy-to-interpret,well-defined clusters.The application of the methodology includes selecting key parameters via grid search and a thorough comparison of clustering distances and methods to ensure the robustness of the results.Further research can test the scalability of the methodology to larger datasets from various customer segments(households and large commercial)and locations with different weather and socioeconomic conditions.展开更多
Radiation detectors, such as survey meters, are essential for ensuring radiation safety in various sectors, including healthcare, industrial processing, emergency response, etc. However, regular calibration and proper...Radiation detectors, such as survey meters, are essential for ensuring radiation safety in various sectors, including healthcare, industrial processing, emergency response, etc. However, regular calibration and proper maintenance of survey meters are important in order to ascertain their accuracy and reliability. This study provides a comprehensive retrospective assessment of the calibration behaviour, durability, and fault trends of 160 survey meters, spanning ten different models. They were calibrated at the Secondary Standard Dosimetry Laboratory (SSDL) in Nigeria over a decade (2012-2023) using an X-Ray Beam Irradiator Model X80-225K and Cs-137 irradiator (OB6) with a PTW reference spherical chamber traceable to the IAEA SSDL in Seibersdorf, Austria. The calibration stability of each model was evaluated, revealing that models like Instrument A and Instrument B demonstrated high reliability with calibration factors close to the ideal value of 1, while models like Instrument C exhibited higher variability, suggesting less consistent performance for dose rate monitoring. Fault analysis showed that the most common issues were related to the battery compartment, indicating a need for improved handling practices. Correlation analysis reveals no statistically significant correlation between calibration factor and age of survey meter across the analysed models. The study concludes that regular calibration, proper handling, and user training are crucial for maintaining the accuracy and longevity of radiation detectors.展开更多
The purpose of this study is to evaluate the price and composition of blood glucose meters and blood glucose test papers in Hubei Province,so as to improve the affordability of blood glucose monitoring for diabetes pa...The purpose of this study is to evaluate the price and composition of blood glucose meters and blood glucose test papers in Hubei Province,so as to improve the affordability of blood glucose monitoring for diabetes patients.Using the standard survey method jointly developed by the World Health Organization(WHO)and Health Action International(HAI)for drug price composition analysis,central level data was collected through literature review,policy review,and interviews with key informants.Field research was conducted in Wuhan and Yichang to trace price data at various levels of the supply chain.At the central level,data shows that China has implemented multiple policies related to the management and pricing of blood glucose meters and test strips,but has not yet introduced price restrictions for blood glucose meters and test strips;At the supply chain level,data shows that the price composition of blood glucose meters and test strips in Hubei Province is mainly composed of manufacturer prices and retail markups,followed by supply chain taxes and wholesale markups.It can be seen from this that China has established a comprehensive medical device registration,sales,quality control and management standard system through a series of policies.At present,China has not issued price policies for blood glucose meters and blood glucose test papers.Therefore,we can reduce product prices by including medical insurance,government subsidies,competitive bidding,and reducing supply chain taxes,thus improving the affordability of blood glucose monitoring for diabetes patients.展开更多
Objective<span style="font-size:10pt;font-family:;" "=""><span style="font-family:Verdana;font-size:12px;">: Determine the Test reliability and the objective validity of ...Objective<span style="font-size:10pt;font-family:;" "=""><span style="font-family:Verdana;font-size:12px;">: Determine the Test reliability and the objective validity of the International Physical Activity Questionnaire (IPAQ). <span style="font-family:Verdana;font-size:12px;">Methods<span style="font-family:Verdana;">:<span style="font-family:Verdana;"> IPAQ was evaluated for test-retest reliability within 6<span style="font-size:10pt;font-family:;" "=""> <span style="font-family:Verdana;">-<span style="font-size:10pt;font-family:;" "=""> <span style="font-size:10pt;font-family:;" "=""><span style="font-family:Verdana;font-size:12px;">8 days of its first administration. Criterion validity was tested comparing IPAQ data with those from an activity meter (Intelligent Device for Energy Expenditure and Activity, IDEEA). <span style="font-family:Verdana;font-size:12px;">Results<span style="font-family:Verdana;font-size:12px;">: The test-retest correlation (n = 71) for items of IPAQ ranged from r = 0.63 to r = 0.74 and w<span style="font-family:Verdana;">as <span style="font-family:Verdana;">r = 0.79 for the total weekly PA in MET*min per week. Average PA (in MET*min/week) measured with the IDEEA meter, decreased from normal (15<span style="font-family:Verdana;">,<span style="font-family:Verdana;">840), to 14<span style="font-family:Verdana;">,<span style="font-family:Verdana;">278 in overweight<span style="font-size:10pt;font-family:;" "=""> <span style="font-family:Verdana;">(BMI<span style="font-size:10pt;font-family:;" "=""> <span style="font-family:Verdana;">><span style="font-size:10pt;font-family:;" "=""> <span style="font-family:Verdana;">25-<span style="font-size:10pt;font-family:;" "=""> <span style="font-family:Verdana;"><<span style="font-size:10pt;font-family:;" "=""> <span style="font-family:Verdana;">30) and further to 12<span style="font-family:Verdana;">,<span style="font-family:Verdana;">803 in obese subjects (>30. BMI). The weekly energy expenditure measured by IDEEA correlated significantly (r = 0<span style="font-family:Verdana;">.<span style="font-family:Verdana;">61,<span style="font-size:10pt;font-family:;" "=""> <span style="font-size:10pt;font-family:;" "=""><span style="font-family:Verdana;font-size:12px;">r<sup><span style="font-family:Verdana;font-size:12px;">2</sup><span style="font-family:Verdana;font-size:12px;"> = 0.38) with the IPAQ data, providing an objective criterion for validity of IPAQ. The mean values of weekly PA estimated from IPAQ (in MET*min/week) differed significantly in the high (15<span style="font-family:Verdana;">,<span style="font-family:Verdana;">690) vs. the low (11<span style="font-family:Verdana;">,<span style="font-family:Verdana;">398) activity groups but not between the moderate (12<span style="font-family:Verdana;">,<span style="font-size:10pt;font-family:;" "=""><span style="font-family:Verdana;font-size:12px;">056) compared to the low PA group. The IPAQ criteria used to categorize subjects as moderately active, erred by including too many low PA subjects. IDEEA measurements in sedentary subjects overestimated their energy expenditure. <span style="font-family:Verdana;font-size:12px;">Conclusions<span style="font-family:Verdana;font-size:12px;">: IPAQ can be reliably used to distinguish low and high PA groups and yields relatively low estimates (−<span style="font-family:Verdana;">18%) of weekly PA in these groups compared to those measured with the activity meter. Stricter criteria are needed to distinguish moderate from low PA groups. Overweight and obese subjects showed significantly lower levels of PA than normal BMI subjects.<span style="font-size:10pt;font-family:;" "=""> <span style="font-family:Verdana;">IDEEA overestimates low levels of PA.展开更多
The design and implementation of mechanical domestic water meters in current industrial organization and intellectual properties have been registered as an invention to solve the problems of current meters. The device...The design and implementation of mechanical domestic water meters in current industrial organization and intellectual properties have been registered as an invention to solve the problems of current meters. The device operation includes inquiry of printing, subscription connection and disconnection in an emergency. This system includes a software and hardware parts on the users and the control center connecting with two-way mobile phone. Central control software sends the message through the wireless telecommunication lines to the user’s software, requesting the desired information and also provides the commands needed to be sent through the same. The same information can also be submitted to the control center. Through the same way, some of advantages of this method are as follows: installing on existing meters, cheap cost of inquiry call meter, the possibility of declaring illegal manipulation to the control center, the exchange of information using information encoding, and manipulating digital meters applying minor changes.展开更多
This study presents the intercomparison of the outdoor environmental gamma dose rates measured using a Nal （TI） based survey meter along with thermoluminescent dosimeters （TLDs） and estimation of excess lifetime c...This study presents the intercomparison of the outdoor environmental gamma dose rates measured using a Nal （TI） based survey meter along with thermoluminescent dosimeters （TLDs） and estimation of excess lifetime cancer risk （ELCR）, for the inhabitants of Poonch division of the Azad Kashmir, Pakistan. CaF2： Dy （TLD-200） card dosimeters were installed at height of 1 m from ground at fifteen different locations covering the entire Poonch division comprising of three districts.展开更多
The purpose of this study is to verify the physiological effect and describe the intensity of training in response to internal and external loads,through Session Rate of Perceived Exertion and Speed High Intensity Dis...The purpose of this study is to verify the physiological effect and describe the intensity of training in response to internal and external loads,through Session Rate of Perceived Exertion and Speed High Intensity Distance in Meters reports,on professional soccer players engaged in weekly training(199 Sessions,43 weeks)and league games(32 official matches).Twenty-two male professional soccer players(n=22)of the Italian national championship under-19 are involved in this study during the season 2014-2015.Daily,Weekly and Monthly RPE(perceived exertion)Session(Borg CR-10 Scale)is a good indicator of the amount of work done:training time multiplied by perceived effort(TL=Training Time×RPE).With Arbitrary units(a.u.)produced by the individual and used for team-based data analysis,we analyze the intensity produced by workout depending on the working time.Furthermore,by means of global positioning system technology(K-Sport,Montelabbate PU,Italy 10 Hz),we statistically established the existing relationship with high intensity speed distance(>16 km/h)and session rate of perceived exertion to describe how the internal(represented by the sum of the stresses that the body undergoes an external load;is strictly subjective)and external loads(the objective quantification of the means used in training km routes,running speed,slope,type of recovery),are correlated(r=0.87,p<0.01,95%CI).The statistical analysis highlights how these methods are suitable to quantifying the high-intensity work done by the soccer player during the workout and the game.展开更多
There are many design parameters in precision planters to be considered such as cell diameter, peripheral speed of roller, number of cells, manner of feeding seeds into cell and travel speed. In precision planters eac...There are many design parameters in precision planters to be considered such as cell diameter, peripheral speed of roller, number of cells, manner of feeding seeds into cell and travel speed. In precision planters each cell must contain only one seed. Therefore, sliding the seed to the cell is important and depends on several parameters such as seed repose angle, seed dimensions and physics of cell. To help the seed to repose in the cell, making a groove on the roller would be very useful. Dimensions of this groove are very important and are considered as basic design parameters. This research was performed to determine some design parameters such as roller speed, travel speed, length and depth of groove for tomato seeds precision planting. In this regard, seeds with a diameter of 4 mm were used. The range of variation was based on calculations obtained. A roller with 42 mm width, 118 mm diameter and 15 cells on the surface was used in the experiment. For each cell, a triangular groove was created on the roller. The groove depth varied from zero at the beginning to the maximum value where the groove connected to the cell. The test unit had a continued and wide belt with 1 l m length. In each replication, planter worked for 20 s to reach a stable state. Thereafter, seeds were allowed to drop on the grease belt. Number of seeds and their spacing were measured on the 4.5 m of the belt. Results showed that the roller speed of 41.5 rpm, the planter travel speed of approximately 1 km/h, groove length of 6-8 mm and groove depth of 1.5 mm can improve planter performance for tomato pelleted seed.展开更多
Shanghai Yatai Meters & Instruments Co. Ltd. was set up in 1991. It is engaged in research and development of meters and instruments for industrial duration measurement and control system. It is a new hi-tech ente...Shanghai Yatai Meters & Instruments Co. Ltd. was set up in 1991. It is engaged in research and development of meters and instruments for industrial duration measurement and control system. It is a new hi-tech enterprise worthy of the name. Recently it has completed the reform of holdings system.展开更多
The design of a new type heat meters based on RFID technology are presented in this paper. By use of RFID technology in heat meters, the data can be exchanged between heat meters and heat supplying department by RF ca...The design of a new type heat meters based on RFID technology are presented in this paper. By use of RFID technology in heat meters, the data can be exchanged between heat meters and heat supplying department by RF cards. The information can be transmitted in a non-contact way. In this way, the purpose of automatic identification can be achieved. The experimental study of the heat meters is also performed in the paper. The results show that the new type of heat meters can meet the demands of users. Compared with the ordinary heat meters, the new type of heat meters have the advantages of small in meter volume, high accuracy, no impact of water quality and good reliability.展开更多
Results of the global shale gas resources show that minable resources of global shale gas are 187 trillion cubic meters （tern）, of which China accounts for 36 tcm （about 20% of the total amount）, which is mainly d...Results of the global shale gas resources show that minable resources of global shale gas are 187 trillion cubic meters （tern）, of which China accounts for 36 tcm （about 20% of the total amount）, which is mainly distributed in the Sichuan Basin, Yangtze Terrace, and Ordos Basin. From 2009 to 2012, China completed an accumulative number of 129 drilling wells related to shale gas, including 46 investigated vertical wells, 55 exploration wells and 28 evaluation wells, with 2012 production ranging from 25 million cubic meters （mcm） to 30 mcm.展开更多
Seismic waves from a magnitude 8.3 earthquake in Japan were consistently recorded by five nearly identical gPhone gravity meters in Colorado. Good correlation was also found in the response of two different types of g...Seismic waves from a magnitude 8.3 earthquake in Japan were consistently recorded by five nearly identical gPhone gravity meters in Colorado. Good correlation was also found in the response of two different types of gravity meters and a standard seismometer in Walferdange, Luxembourg to an earthquake of magnitude 8.2 in Japan, indicating that all of them were capable of measuring the surface waves reliably. The gravity meters, however, recorded 11 separate arrivals of Raleigh waves, while the seismometer only one. Thus the gravity meters may be useful for obtaining new information in the study of seismic velocities, attenuation and dispersion.展开更多
基金supported by the Spanish Ministry of Science and Innovation under Projects PID2022-137680OB-C32 and PID2022-139187OB-I00.
文摘Customer segmentation according to load-shape profiles using smart meter data is an increasingly important application to vital the planning and operation of energy systems and to enable citizens’participation in the energy transition.This study proposes an innovative multi-step clustering procedure to segment customers based on load-shape patterns at the daily and intra-daily time horizons.Smart meter data is split between daily and hourly normalized time series to assess monthly,weekly,daily,and hourly seasonality patterns separately.The dimensionality reduction implicit in the splitting allows a direct approach to clustering raw daily energy time series data.The intraday clustering procedure sequentially identifies representative hourly day-unit profiles for each customer and the entire population.For the first time,a step function approach is applied to reduce time series dimensionality.Customer attributes embedded in surveys are employed to build external clustering validation metrics using Cramer’s V correlation factors and to identify statistically significant determinants of load-shape in energy usage.In addition,a time series features engineering approach is used to extract 16 relevant demand flexibility indicators that characterize customers and corresponding clusters along four different axes:available Energy(E),Temporal patterns(T),Consistency(C),and Variability(V).The methodology is implemented on a real-world electricity consumption dataset of 325 Small and Medium-sized Enterprise(SME)customers,identifying 4 daily and 6 hourly easy-to-interpret,well-defined clusters.The application of the methodology includes selecting key parameters via grid search and a thorough comparison of clustering distances and methods to ensure the robustness of the results.Further research can test the scalability of the methodology to larger datasets from various customer segments(households and large commercial)and locations with different weather and socioeconomic conditions.
文摘Radiation detectors, such as survey meters, are essential for ensuring radiation safety in various sectors, including healthcare, industrial processing, emergency response, etc. However, regular calibration and proper maintenance of survey meters are important in order to ascertain their accuracy and reliability. This study provides a comprehensive retrospective assessment of the calibration behaviour, durability, and fault trends of 160 survey meters, spanning ten different models. They were calibrated at the Secondary Standard Dosimetry Laboratory (SSDL) in Nigeria over a decade (2012-2023) using an X-Ray Beam Irradiator Model X80-225K and Cs-137 irradiator (OB6) with a PTW reference spherical chamber traceable to the IAEA SSDL in Seibersdorf, Austria. The calibration stability of each model was evaluated, revealing that models like Instrument A and Instrument B demonstrated high reliability with calibration factors close to the ideal value of 1, while models like Instrument C exhibited higher variability, suggesting less consistent performance for dose rate monitoring. Fault analysis showed that the most common issues were related to the battery compartment, indicating a need for improved handling practices. Correlation analysis reveals no statistically significant correlation between calibration factor and age of survey meter across the analysed models. The study concludes that regular calibration, proper handling, and user training are crucial for maintaining the accuracy and longevity of radiation detectors.
基金Hubei Provincial Medical Institutions at all levels of basic drugs and drug bridging support policy projectsResearch on the Integrated Development of Disease Prevention and Control and Medical Services in the XPCC under the Background of Healthy China (Grant No. BTJKJ2024003)。
文摘The purpose of this study is to evaluate the price and composition of blood glucose meters and blood glucose test papers in Hubei Province,so as to improve the affordability of blood glucose monitoring for diabetes patients.Using the standard survey method jointly developed by the World Health Organization(WHO)and Health Action International(HAI)for drug price composition analysis,central level data was collected through literature review,policy review,and interviews with key informants.Field research was conducted in Wuhan and Yichang to trace price data at various levels of the supply chain.At the central level,data shows that China has implemented multiple policies related to the management and pricing of blood glucose meters and test strips,but has not yet introduced price restrictions for blood glucose meters and test strips;At the supply chain level,data shows that the price composition of blood glucose meters and test strips in Hubei Province is mainly composed of manufacturer prices and retail markups,followed by supply chain taxes and wholesale markups.It can be seen from this that China has established a comprehensive medical device registration,sales,quality control and management standard system through a series of policies.At present,China has not issued price policies for blood glucose meters and blood glucose test papers.Therefore,we can reduce product prices by including medical insurance,government subsidies,competitive bidding,and reducing supply chain taxes,thus improving the affordability of blood glucose monitoring for diabetes patients.
文摘Objective<span style="font-size:10pt;font-family:;" "=""><span style="font-family:Verdana;font-size:12px;">: Determine the Test reliability and the objective validity of the International Physical Activity Questionnaire (IPAQ). <span style="font-family:Verdana;font-size:12px;">Methods<span style="font-family:Verdana;">:<span style="font-family:Verdana;"> IPAQ was evaluated for test-retest reliability within 6<span style="font-size:10pt;font-family:;" "=""> <span style="font-family:Verdana;">-<span style="font-size:10pt;font-family:;" "=""> <span style="font-size:10pt;font-family:;" "=""><span style="font-family:Verdana;font-size:12px;">8 days of its first administration. Criterion validity was tested comparing IPAQ data with those from an activity meter (Intelligent Device for Energy Expenditure and Activity, IDEEA). <span style="font-family:Verdana;font-size:12px;">Results<span style="font-family:Verdana;font-size:12px;">: The test-retest correlation (n = 71) for items of IPAQ ranged from r = 0.63 to r = 0.74 and w<span style="font-family:Verdana;">as <span style="font-family:Verdana;">r = 0.79 for the total weekly PA in MET*min per week. Average PA (in MET*min/week) measured with the IDEEA meter, decreased from normal (15<span style="font-family:Verdana;">,<span style="font-family:Verdana;">840), to 14<span style="font-family:Verdana;">,<span style="font-family:Verdana;">278 in overweight<span style="font-size:10pt;font-family:;" "=""> <span style="font-family:Verdana;">(BMI<span style="font-size:10pt;font-family:;" "=""> <span style="font-family:Verdana;">><span style="font-size:10pt;font-family:;" "=""> <span style="font-family:Verdana;">25-<span style="font-size:10pt;font-family:;" "=""> <span style="font-family:Verdana;"><<span style="font-size:10pt;font-family:;" "=""> <span style="font-family:Verdana;">30) and further to 12<span style="font-family:Verdana;">,<span style="font-family:Verdana;">803 in obese subjects (>30. BMI). The weekly energy expenditure measured by IDEEA correlated significantly (r = 0<span style="font-family:Verdana;">.<span style="font-family:Verdana;">61,<span style="font-size:10pt;font-family:;" "=""> <span style="font-size:10pt;font-family:;" "=""><span style="font-family:Verdana;font-size:12px;">r<sup><span style="font-family:Verdana;font-size:12px;">2</sup><span style="font-family:Verdana;font-size:12px;"> = 0.38) with the IPAQ data, providing an objective criterion for validity of IPAQ. The mean values of weekly PA estimated from IPAQ (in MET*min/week) differed significantly in the high (15<span style="font-family:Verdana;">,<span style="font-family:Verdana;">690) vs. the low (11<span style="font-family:Verdana;">,<span style="font-family:Verdana;">398) activity groups but not between the moderate (12<span style="font-family:Verdana;">,<span style="font-size:10pt;font-family:;" "=""><span style="font-family:Verdana;font-size:12px;">056) compared to the low PA group. The IPAQ criteria used to categorize subjects as moderately active, erred by including too many low PA subjects. IDEEA measurements in sedentary subjects overestimated their energy expenditure. <span style="font-family:Verdana;font-size:12px;">Conclusions<span style="font-family:Verdana;font-size:12px;">: IPAQ can be reliably used to distinguish low and high PA groups and yields relatively low estimates (−<span style="font-family:Verdana;">18%) of weekly PA in these groups compared to those measured with the activity meter. Stricter criteria are needed to distinguish moderate from low PA groups. Overweight and obese subjects showed significantly lower levels of PA than normal BMI subjects.<span style="font-size:10pt;font-family:;" "=""> <span style="font-family:Verdana;">IDEEA overestimates low levels of PA.
文摘The design and implementation of mechanical domestic water meters in current industrial organization and intellectual properties have been registered as an invention to solve the problems of current meters. The device operation includes inquiry of printing, subscription connection and disconnection in an emergency. This system includes a software and hardware parts on the users and the control center connecting with two-way mobile phone. Central control software sends the message through the wireless telecommunication lines to the user’s software, requesting the desired information and also provides the commands needed to be sent through the same. The same information can also be submitted to the control center. Through the same way, some of advantages of this method are as follows: installing on existing meters, cheap cost of inquiry call meter, the possibility of declaring illegal manipulation to the control center, the exchange of information using information encoding, and manipulating digital meters applying minor changes.
文摘This study presents the intercomparison of the outdoor environmental gamma dose rates measured using a Nal （TI） based survey meter along with thermoluminescent dosimeters （TLDs） and estimation of excess lifetime cancer risk （ELCR）, for the inhabitants of Poonch division of the Azad Kashmir, Pakistan. CaF2： Dy （TLD-200） card dosimeters were installed at height of 1 m from ground at fifteen different locations covering the entire Poonch division comprising of three districts.
文摘The purpose of this study is to verify the physiological effect and describe the intensity of training in response to internal and external loads,through Session Rate of Perceived Exertion and Speed High Intensity Distance in Meters reports,on professional soccer players engaged in weekly training(199 Sessions,43 weeks)and league games(32 official matches).Twenty-two male professional soccer players(n=22)of the Italian national championship under-19 are involved in this study during the season 2014-2015.Daily,Weekly and Monthly RPE(perceived exertion)Session(Borg CR-10 Scale)is a good indicator of the amount of work done:training time multiplied by perceived effort(TL=Training Time×RPE).With Arbitrary units(a.u.)produced by the individual and used for team-based data analysis,we analyze the intensity produced by workout depending on the working time.Furthermore,by means of global positioning system technology(K-Sport,Montelabbate PU,Italy 10 Hz),we statistically established the existing relationship with high intensity speed distance(>16 km/h)and session rate of perceived exertion to describe how the internal(represented by the sum of the stresses that the body undergoes an external load;is strictly subjective)and external loads(the objective quantification of the means used in training km routes,running speed,slope,type of recovery),are correlated(r=0.87,p<0.01,95%CI).The statistical analysis highlights how these methods are suitable to quantifying the high-intensity work done by the soccer player during the workout and the game.
文摘There are many design parameters in precision planters to be considered such as cell diameter, peripheral speed of roller, number of cells, manner of feeding seeds into cell and travel speed. In precision planters each cell must contain only one seed. Therefore, sliding the seed to the cell is important and depends on several parameters such as seed repose angle, seed dimensions and physics of cell. To help the seed to repose in the cell, making a groove on the roller would be very useful. Dimensions of this groove are very important and are considered as basic design parameters. This research was performed to determine some design parameters such as roller speed, travel speed, length and depth of groove for tomato seeds precision planting. In this regard, seeds with a diameter of 4 mm were used. The range of variation was based on calculations obtained. A roller with 42 mm width, 118 mm diameter and 15 cells on the surface was used in the experiment. For each cell, a triangular groove was created on the roller. The groove depth varied from zero at the beginning to the maximum value where the groove connected to the cell. The test unit had a continued and wide belt with 1 l m length. In each replication, planter worked for 20 s to reach a stable state. Thereafter, seeds were allowed to drop on the grease belt. Number of seeds and their spacing were measured on the 4.5 m of the belt. Results showed that the roller speed of 41.5 rpm, the planter travel speed of approximately 1 km/h, groove length of 6-8 mm and groove depth of 1.5 mm can improve planter performance for tomato pelleted seed.
文摘Shanghai Yatai Meters & Instruments Co. Ltd. was set up in 1991. It is engaged in research and development of meters and instruments for industrial duration measurement and control system. It is a new hi-tech enterprise worthy of the name. Recently it has completed the reform of holdings system.
文摘The design of a new type heat meters based on RFID technology are presented in this paper. By use of RFID technology in heat meters, the data can be exchanged between heat meters and heat supplying department by RF cards. The information can be transmitted in a non-contact way. In this way, the purpose of automatic identification can be achieved. The experimental study of the heat meters is also performed in the paper. The results show that the new type of heat meters can meet the demands of users. Compared with the ordinary heat meters, the new type of heat meters have the advantages of small in meter volume, high accuracy, no impact of water quality and good reliability.
文摘Results of the global shale gas resources show that minable resources of global shale gas are 187 trillion cubic meters （tern）, of which China accounts for 36 tcm （about 20% of the total amount）, which is mainly distributed in the Sichuan Basin, Yangtze Terrace, and Ordos Basin. From 2009 to 2012, China completed an accumulative number of 129 drilling wells related to shale gas, including 46 investigated vertical wells, 55 exploration wells and 28 evaluation wells, with 2012 production ranging from 25 million cubic meters （mcm） to 30 mcm.
文摘Seismic waves from a magnitude 8.3 earthquake in Japan were consistently recorded by five nearly identical gPhone gravity meters in Colorado. Good correlation was also found in the response of two different types of gravity meters and a standard seismometer in Walferdange, Luxembourg to an earthquake of magnitude 8.2 in Japan, indicating that all of them were capable of measuring the surface waves reliably. The gravity meters, however, recorded 11 separate arrivals of Raleigh waves, while the seismometer only one. Thus the gravity meters may be useful for obtaining new information in the study of seismic velocities, attenuation and dispersion.
