Journal articles: 'Electrostatic precipitation Automatic control'

1

Durga Prasad, N. V. P. R., T. Lakshminarayana, J. R. K. Narasimham, T. M. Verman, and C. S. R. Krishnam Raju. "Automatic control and management of electrostatic precipitator." IEEE Transactions on Industry Applications 35, no. 3 (1999): 561–67. http://dx.doi.org/10.1109/28.767002.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Zhang, Zi Sheng, Yi Wang, Chun Sheng Wang, Jin Cui, and Zhi Qiang Liu. "The Control of High Voltage Electrostatic Precipitator Based on EDA." Advanced Materials Research 910 (March 2014): 336–39. http://dx.doi.org/10.4028/www.scientific.net/amr.910.336.

Full text

Abstract:

In order to achieve the automatic control of electrostatic precipitator (ESP) more efficiently and accurately, an ESP system combining hardware and software is designed. According to the requirement of the ESP system,the Electronic Design Automation (EDA) is introduced to the ESP control system and the system is divided into four modules.These sub-modules are designed and the simulation waveform of the system is ananalyzed,based on the Very-High-Speed Integrated Circuit Hardware Description Language (VHDL) programming language and Quartus software.The results show that the security, flexibility and reliabity of the system is improved by using EDA as the control ,which is a great value for generalization.

APA, Harvard, Vancouver, ISO, and other styles

3

Mo, Hai Ping, Li Na Gao, and Biao Xu. "Automobile Electrostatic Precipitator." Applied Mechanics and Materials 713-715 (January 2015): 611–14. http://dx.doi.org/10.4028/www.scientific.net/amm.713-715.611.

Full text

Abstract:

Road dust is an important part of the atmospheric particulate pollutants, which has become one of the important factors influencing the quality of our environment of the city. Espescially in the northern city. The air particles contributes more than 50% in the road dust. Particle diameter of the particles below 10um is the greatest harm to the health of human beings. At present, the city of this control mostly adopt sprinkler, manual cleaning and other traditional way. The dust removal effect is not significant and cost a considerable human, material and financial resources. So this paper quotes the electrostatic dust removal principle of thermal power plant to design a new type of device used in road dust cleaning. Its energy consumption is small, high absorption efficiency. The influence of automobile driving resistance is small. To be located in the rear of the car, it will complete the whole removal process in automatic car running. Do not need to complete the staff involved, greatly saves manpower cost. It also can suck tiny particles in addition to PM10, PM2.5 and so on, can greatly improve the city's air quality.

APA, Harvard, Vancouver, ISO, and other styles

4

Li, Shuran, Jianmin Liu, Shilong Wang, Guanlei Deng, Qinzhen Zheng, Ping Han, Ruixin Li, Jianming Xue, Keping Yan, and Zhen Liu. "Electrical control of electrostatic precipitation." Journal of Physics D: Applied Physics 51, no. 30 (July 5, 2018): 304005. http://dx.doi.org/10.1088/1361-6463/aaccc7.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Zhang, Zi Sheng, Chun Sheng Wang, Yi Wang, Zhan You Wang, and Deng Yuan Song. "Power and Vibration of Electrostatic Precipitator Control Based on FPGA." Advanced Materials Research 1037 (October 2014): 244–47. http://dx.doi.org/10.4028/www.scientific.net/amr.1037.244.

Full text

Abstract:

In order to improve the automation level of the electrostatic precipitator, we used Very-High-Speed Integrated Circuit Hardware Description Language (VHDL) language to compile, emulate and optimize the control system of power source and vibration. In the design of Quartus platform, we used EP1C3T144C8 Field Programmable Gate Array (FPGA) chip to realize high voltage power supply, alarm and protection system. We also realized the compilation and simulation test of each part’s function of 20 s rapping and 40 min rapping cycle. At the same time, we recorded the waveform of simulation. It demonstrated that the validity of the relevant VHDL compilation. We used this method to achieve the optimization control of the electrostatic precipitator operating parameters. It has a strong practicability.

APA, Harvard, Vancouver, ISO, and other styles

6

Li, Chih-Shan, and Yi-Mien Wen. "Control Effectiveness of Electrostatic Precipitation on Airborne Microorganisms." Aerosol Science and Technology 37, no. 12 (December 2003): 933–38. http://dx.doi.org/10.1080/02786820300903.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Hayashi, Hideaki, Yasuhiro Takasaki, Kazuki Kawahara, Kazunori Takashima, and Akira Mizuno. "Electrostatic Charging and Precipitation of Diesel Soot." IEEE Transactions on Industry Applications 47, no. 1 (January 2011): 331–35. http://dx.doi.org/10.1109/tia.2010.2090846.

Full text

APA, Harvard, Vancouver, ISO, and other styles

8

Zhenwu, Sun, Huo Yuping, Liu Gencheng, Li Yuxiao, and Li Tao. "Automatic Control System of Ion Electrostatic Accelerator and Anti-Interference Measures." Plasma Science and Technology 9, no. 1 (February 2007): 101–5. http://dx.doi.org/10.1088/1009-0630/9/1/20.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Karakashev, Stoyan I., Nikolay A. Grozev, Svetlana Hristova, Kristina Mircheva, and Orhan Ozdemir. "Electrostatic Forces in Control of the Foamability of Nonionic Surfactant." Coatings 13, no. 1 (December 25, 2022): 37. http://dx.doi.org/10.3390/coatings13010037.

Full text

Abstract:

Can the DLVO theory predict the foamability of flotation frothers as MIBC (methyl isobutyl carbinol)? The flotation froth is a multi-bubble system, in which the bubbles collide, thus either coalescing or rebounding. This scenario is driven by the hydrodynamic push force, pressing the bubbles towards each other, the electrostatic and van der Waals forces between the bubbles, and the occurrence of the precipitation of the dissolved air between the bubbles. We studied the foamability of 20 ppm MIBC at constant ionic strength I = 7.5 × 10−4 mol/L at different pH values in the absence and presence of modified silica particles, which were positively charged, thus covering the negatively charged bubbles. Hence, we observed an increase in the foamability with the increase in the pH value until pH = 8.3, beyond which it decreased. The electrostatic repulsion between the bubbles increased with the increase in the pH value, which caused the electrostatic stabilization of the froth and subsequently an increase in the foamability. The presence of the particles covering the bubbles boosted the foamability also due to the steric repulsion between the bubbles. The decrease in the foamability at pH > 8.3 can be explained by the fact that, under such conditions, the solubility of carbon dioxide vanished, thus making the aqueous solution supersaturated with carbon dioxide. This caused the precipitation of the latter and the emergence of microbubbles, which usually make the bubbles coalesce. Of course, our explanation remains a hypothesis.

APA, Harvard, Vancouver, ISO, and other styles

10

Hanne, Orava, Nordman Timo, and Kuopanportti Hannu. "Increase the utilisation of fly ash with electrostatic precipitation." Minerals Engineering 19, no. 15 (December 2006): 1596–602. http://dx.doi.org/10.1016/j.mineng.2006.07.002.

Full text

APA, Harvard, Vancouver, ISO, and other styles

11

Ross, Amber, Craig D. Smith, and Alan Barr. "An improved post-processing technique for automatic precipitation gauge time series." Atmospheric Measurement Techniques 13, no. 6 (June 5, 2020): 2979–94. http://dx.doi.org/10.5194/amt-13-2979-2020.

Full text

Abstract:

Abstract. The unconditioned data retrieved from accumulating automated weighing precipitation gauges are inherently noisy due to the sensitivity of the instruments to mechanical and electrical interference. This noise, combined with diurnal oscillations and signal drift from evaporation of the bucket contents, can make accurate precipitation estimates challenging. Relative to rainfall, errors in the measurement of solid precipitation are exacerbated because the lower accumulation rates are more impacted by measurement noise. Precipitation gauge measurement post-processing techniques are used by Environment and Climate Change Canada in research and operational monitoring to filter cumulative precipitation time series derived from high-frequency, bucket-weight measurements. Four techniques are described and tested here: (1) the operational 15 min filter (O15), (2) the neutral aggregating filter (NAF), (3) the supervised neutral aggregating filter (NAF-S), and (4) the segmented neutral aggregating filter (NAF-SEG). Inherent biases and errors in the first two post-processing techniques have revealed the need for a robust automated method to derive an accurate noise-free precipitation time series from the raw bucket-weight measurements. The method must be capable of removing random noise, diurnal oscillations, and evaporative (negative) drift from the raw data. This evaluation primarily focuses on cold-season (October to April) accumulating automated weighing precipitation gauge data at 1 min resolution from two sources: a control (pre-processed time series) with added synthetic noise and drift and raw (minimally processed) data from several WMO Solid Precipitation Intercomparison Experiment (SPICE) sites. Evaluation against the control with synthetic noise shows the effectiveness of the NAF-SEG technique, recovering 99 %, 100 %, and 102 % of the control total precipitation for low-, medium-, and high-noise scenarios respectively for the cold-season (October–April) and 97 % of the control total precipitation for all noise scenarios in the warm season (May–September). Among the filters, the fully automated NAF-SEG produced the highest correlation coefficients and lowest root-mean-square error (RMSE) for all synthetic noise levels, with comparable performance to the supervised and manually intensive NAF-S method. Compared to the O15 method in cold-season testing, NAF-SEG shows a lower bias in 37 of 44 real-world test cases, a similar bias in 5 cases, and a higher bias in 2 cases. In warm-season testing, the NAF-SEG bias was lower or similar in 7 of 11 cases. The results indicate that the NAF-SEG post-processing technique provides substantial improvement over current automated techniques, reducing both uncertainty and bias in accumulating-gauge measurements of precipitation, with a 24 h latency. Because it cannot be implemented in real time, we recommend that NAF-SEG be used in combination with a simple real-time filter, such as the O15 or similar filter.

APA, Harvard, Vancouver, ISO, and other styles

12

Jørgensen, H. K., S. Rosenørn, H. Madsen, and P. S. Mikkelsen. "Quality control of rain data used for urban runoff systems." Water Science and Technology 37, no. 11 (June 1, 1998): 113–20. http://dx.doi.org/10.2166/wst.1998.0448.

Full text

Abstract:

When improving software packages such as MOUSE and SAMBA for designing sewers and storage basins, and simulating overflows and flooding the quality of the input becomes important. The essential input to these modelling tools are the historical rain series. This paper presents the procedures for collection and quality control of rain data from a network of tipping bucket rain gauges in Denmark carried out by the Danish Meteorological Institute. During rain, the RIMCO gauge counts the number of tips (each of 0.2 mm of precipitation) every minute. The quality control of the rain data includes an automatic and a manual bit marking, where the automatic control basically is pointing out minutes with extreme intensities. In the manual control, the maximum intensities as well as the daily totals of precipitation are inspected, using weather charts, intensity plots and precipitation sums of nearby Hellmann gauges. Shortcomings and improvements of the quality control are discussed. Although, it is possible to improve the efficiency of the quality control, long term corrections will always be necessary.

APA, Harvard, Vancouver, ISO, and other styles

13

Nelson, Brian R., D.-J. Seo, and Dongsoo Kim. "Multisensor Precipitation Reanalysis." Journal of Hydrometeorology 11, no. 3 (June 1, 2010): 666–82. http://dx.doi.org/10.1175/2010jhm1210.1.

Full text

Abstract:

Abstract Temporally consistent high-quality, high-resolution multisensor precipitation reanalysis (MPR) products are needed for a wide range of quantitative climatological and hydroclimatological applications. Therefore, the authors have reengineered the multisensor precipitation estimator (MPE) algorithms of the NWS into the MPR package. Owing to the retrospective nature of the analysis, MPR allows for the utilization of additional rain gauge data, more rigorous automatic quality control, and post factum correction of radar quantitative precipitation estimation (QPE) and optimization of key parameters in multisensor estimation. To evaluate and demonstrate the value of MPR, the authors designed and carried out a set of cross-validation experiments in the pilot domain of North Carolina and South Carolina. The rain gauge data are from the reprocessed Hydrometeorological Automated Data System (HADS) and the daily Cooperative Observer Program (COOP). The radar QPE data are the operationally produced Weather Surveillance Radar-1988 Doppler digital precipitation array (DPA) products. To screen out bad rain gauge data, quality control steps were taken that use rain gauge and radar data. The resulting MPR products are compared with the stage IV product on a daily scale at the withheld COOP gauge locations. This paper describes the data, the MPR procedure, and the validation experiments, and it summarizes the findings.

APA, Harvard, Vancouver, ISO, and other styles

14

Ingildsen, P., and H. Wendelboe. "Improved nutrient removal using in situ continuous on-line sensors with short response time." Water Science and Technology 48, no. 1 (July 1, 2003): 95–102. http://dx.doi.org/10.2166/wst.2003.0025.

Full text

Abstract:

Nutrient sensors that can be located directly in the activated sludge processes are gaining in number at wastewater treatment plants. The in situ location of the sensors means that they can be located close to the processes that they aim to control and hence are perfectly suited for automatic process control. Compared to the location of automatic analysers in the effluent from the sedimentation reactors the in situ location means a large reduction in the response time. The settlers typically work as a first-order delay on the signal with a retention time in the range of 4-12 hours depending on the size of the settlers. Automatic process control of the nitrogen and phosphorus removal processes means that considerable improvements in the performance of aeration, internal recirculation, carbon dosage and phosphate precipitation dosage can be reached by using a simple control structure as well as simple PID controllers. The performance improvements can be seen in decreased energy and chemicals consumption and less variation in effluent concentrations of ammonium, total nitrogen and phosphate. Simple control schemes are demonstrated for the pre-denitrification and the post precipitation system by means of full-scale plant experiments and model simulations.

APA, Harvard, Vancouver, ISO, and other styles

15

Tamura, Moriaki. "An automatic system for controlling snow on roofs." Annals of Glaciology 18 (1993): 113–16. http://dx.doi.org/10.3189/s0260305500011356.

Full text

Abstract:

In Honshu Island, Japan, tremendous amounts of snow falls over a vast area facing the Sea of Japan. The depth of deposited snow sometimes exceeds 2 m, even in urban areas. The weight of snow on roofs can damage conventional wooden houses. It is of great importance, therefore, to monitor and control roof snow loads.A model system has been developed for controlling snow on roofs. A precipitation detector capable of differentiating between solid and liquid precipitation and a water gauge for detecting the meltwater from a roof are combined to estimate the roof snow load. When the calculated load exceeds a critical value, an electric heater on the roof is energized to melt a portion of the snow. The whole system is controlled by a personal computer. The system was tested for about a month in 1990 with satisfactory results.

APA, Harvard, Vancouver, ISO, and other styles

16

Tamura, Moriaki. "An automatic system for controlling snow on roofs." Annals of Glaciology 18 (1993): 113–16. http://dx.doi.org/10.1017/s0260305500011356.

Full text

Abstract:

In Honshu Island, Japan, tremendous amounts of snow falls over a vast area facing the Sea of Japan. The depth of deposited snow sometimes exceeds 2 m, even in urban areas. The weight of snow on roofs can damage conventional wooden houses. It is of great importance, therefore, to monitor and control roof snow loads. A model system has been developed for controlling snow on roofs. A precipitation detector capable of differentiating between solid and liquid precipitation and a water gauge for detecting the meltwater from a roof are combined to estimate the roof snow load. When the calculated load exceeds a critical value, an electric heater on the roof is energized to melt a portion of the snow. The whole system is controlled by a personal computer. The system was tested for about a month in 1990 with satisfactory results.

APA, Harvard, Vancouver, ISO, and other styles

17

Liu, Xiaoyan, Honghui Zheng, Zhenli Chen, and Yi Jiang. "A Multi-Component Synthesis Scoring Method of Gridded Fusion Products for Precipitation Quality Control." Atmosphere 13, no. 9 (September 6, 2022): 1446. http://dx.doi.org/10.3390/atmos13091446.

Full text

Abstract:

A crucial and fundamental type of precipitation monitoring is the automatic observation of precipitation by ground stations. However, the typical quality control methods that are applied to rainfall present restrictions because of their discontinuities in time and space. The multi-component comprehensive consistency approach is a subjective quality control method that uses changes in other weather components associated with the precipitation process. The present study determined the reference weather components for precipitation by calculating the correlation coefficients between weather components and precipitation, and the proportions that passed the significance tests. These components included air pressure, visibility, relative humidity, wind speed, temperature difference, and the sum of cloud covers of 125–875 hPa. This study introduced various gridded fusion products to fill in the empty spaces of weather components, and put forward a scoring method to convert a subjective method into an objective method. The outcomes of the scoring method are assessed using the artificial quality control results. The evaluation’s findings demonstrate that the scoring method’s accuracy in every period of precipitation is greater than 0.75, meeting the need for objective quality control of real-time surface precipitation.

APA, Harvard, Vancouver, ISO, and other styles

18

Ośródka, Katarzyna, Irena Otop, and Jan Szturc. "Automatic quality control of telemetric rain gauge data providing quantitative quality information (RainGaugeQC)." Atmospheric Measurement Techniques 15, no. 19 (October 4, 2022): 5581–97. http://dx.doi.org/10.5194/amt-15-5581-2022.

Full text

Abstract:

Abstract. The RainGaugeQC scheme described in this paper is intended for real-time quality control of telemetric rain gauge data. It consists of several checks: detection of exceedance of the natural limit and climate-based threshold as well as checking of the conformity of rain gauge and radar observations, the consistency of time series from heated and unheated sensors, and the spatial consistency of adjacent gauges. The proposed approach is focused on assessing the reliability of individual rain gauge observations. A quantitative indicator of reliability, called the quality index (QI), describes the quality of each measurement as a number in the range from 0.0 (completely unreliable measurement) to 1.0 (perfect measurement). The QI of a measurement which fails any check is lowered, and only a measurement very likely to be erroneous is replaced with a “no data” value. The performance of this scheme has been evaluated by analysing the spatial distribution of the precipitation field and comparing it with precipitation observations and estimates provided by other techniques. The effectiveness of the RainGaugeQC scheme was also analysed in terms of the statistics of QI reduction. The quality information provided is very useful in further applications of rain gauge data. The scheme is used operationally by the Polish national meteorological and hydrological service (Institute of Meteorology and Water Management – National Research Institute).

APA, Harvard, Vancouver, ISO, and other styles

19

Sun, Chao Fan, Xing Lu Yu, Xin Feng Long, Bo Lou, and De Bo Li. "Study on the Operation Characteristics of Electrostatic Fabric Precipitator." Advanced Materials Research 616-618 (December 2012): 2013–16. http://dx.doi.org/10.4028/www.scientific.net/amr.616-618.2013.

Full text

Abstract:

Numerical simulation method was used in this paper and 3-D structure of model was established with Pro/Engineering. It is evident that the efficiency of electric-bag is related to internal fluid field. The internal fluid field characteristics (pressure field, velocity field, turbulence field and particle tracks) are obtained by the numerical simulation soft called Fluent, the result show that airflow distribution could be improved obviously by the flow deflectors in electrostatic precipitation area. And the distribution of DPM in filter area is non uniform, which would lead to various damage on bags and affect the operation of electrostatic fabric filter. All these work have important significance for the study of new dust removal technology, developments of high performance precipitator, reduction of dust pollution and control of air pollution as well.

APA, Harvard, Vancouver, ISO, and other styles

20

Badran, Mohamed, and Abdallah Mahmoud Mansour. "Evaluating Performance Indices of Electrostatic Precipitators." Energies 15, no. 18 (September 11, 2022): 6647. http://dx.doi.org/10.3390/en15186647.

Full text

Abstract:

Utilizing electrostatic precipitators (ESPs) is an efficient particle removal method that sees a wide usage in industrial environments. This is mainly because of the low drop of the pressure flow, while retaining high collection efficiency, alongside being cost-effective. This paper reviewed previous works concerning optimizing the performance of single- and multi-stage ESPs by changing several design parameters and evaluating the effects on different performance indices, such as the corona power ratio, current-voltage characteristics, and overall collection efficiency. The review then goes through several modelling methodologies, showcasing their shortcomings and developments, as well as the relationship between the electrohydrodynamic (EHD) flow and the precipitation performance. The performance effects of using different electrode configurations and designs in terms of the number of electrodes, relative dimensions, spacings, channel lengths, and overall design were also reviewed.

APA, Harvard, Vancouver, ISO, and other styles

21

Johnston, A. M., G. W. Hughson, J. H. Vincent, and A. D. Jones. "Localized Electrostatic Precipitation as an Alternative to Exhaust Ventilation for Controlling Airborne Dust in Textile Workplaces." Textile Research Journal 58, no. 11 (November 1988): 619–25. http://dx.doi.org/10.1177/004051758805801101.

Full text

Abstract:

We report the results of a series of investigations to assess the possible use of localized electrostatic precipitation as a practical, cost-effective alternative to local exhaust ventilation for control of airborne dust levels in the workplace. A brief summary is given of work in the laboratory using both an experimental chamber and a dust control cabinet fitted to a textile winding rig. These studies have been extended to include a pilot trial on an open-bed spinning frame in an asbestos textile factory. A detailed account of the procedures and results of this latter study is given. The possible advantages of electrostatically based systems in terms of cost-efficiency are considered against possible disadvantages associated with operational accessibility.

APA, Harvard, Vancouver, ISO, and other styles

22

Liu, Heng, Jiale Wu, and Yu Zhang. "Coupled Double Closed-Loop Control for an MEMS Resonant Accelerometer." Micromachines 13, no. 10 (September 27, 2022): 1612. http://dx.doi.org/10.3390/mi13101612.

Full text

Abstract:

There is mutual coupling between amplitude control and frequency tracking control in the closed-loop control of micromechanical resonant sensors, which restricts sensor performance. This paper introduces the principle of an in-plane vibration micromechanical resonant accelerometer with electrostatic stiffness. The characteristic parameters of the microaccelerometer were obtained through computer-aided dimension measurement and an open-loop frequency sweep test of the fabricated microstructure. An accurate numerical model was established based on the accelerometer’s dynamic principle and characteristic parameters. We established the double closed-loop driving analysis model of amplitude automatic gain control and resonant frequency phase-locked tracking. We used the averaging method to analyze the steady-state equilibrium point and the stable condition. We concluded that the integral coefficient can improve the startup overshoot when the amplitude automatic gain control loop satisfies the stability condition. Under the constraint of frequency tracking, the sizeable coefficient of the integrator can improve the system instability of the amplitude control loop. The theoretical analysis and simulation were helpful in the design and debugging of the system circuit.

APA, Harvard, Vancouver, ISO, and other styles

23

Zhou, Rong Fu, Ding Xin Shuai, Yu Tang, and Xue Tong Zhang. "Fuzzy Control System of Titanium Dioxide Hydrolysis Process." Applied Mechanics and Materials 128-129 (October 2011): 882–85. http://dx.doi.org/10.4028/www.scientific.net/amm.128-129.882.

Full text

Abstract:

Hydrolysis process is the key part of sulfuric acid method’s production technology of titanium dioxide, it is also the most rigorous part of the process control, and precipitate out the white hydration precipitation TiO2 from the mother liquor, and separate from other soluble metal sundry ions, further purify the TiO2. The quality of hydrolysis product not only affects the normal operation of the follow-up, but also affects the quality of the final product directly. This article do some study and design to the hydrolysis automatic control, use computer，DCS and PLC control the hydrolysis operation process, temperature control, steam heating system, That means comprised monitoring station by the DCS，CRT, mouse and keyboard replace the simulates panel and operator, and use the fuzzy theory control the hydrolysis temperature rise process, improve the accuracy and precision of the operating, at the same time, reduce the labor intensity of the workers, realize the automatic control of the hydrolysis process, stabilize and improve the product quality effectively

APA, Harvard, Vancouver, ISO, and other styles

24

Zhang, Zi Sheng, Bo Feng Liu, Shu Qing Guo, Deng Yuan Song, and Zhan You Wang. "Application of Programmable Logic Controller in Sewage Treatment." Advanced Materials Research 910 (March 2014): 332–35. http://dx.doi.org/10.4028/www.scientific.net/amr.910.332.

Full text

Abstract:

In order to seek a better way of control in sewage treatment, a control system which consisted of water unit, sand unit, the oxidation ditch unit, precipitation unit and sludge dewatering unit was designed. The paper investigates various controllable parameters in sewage treatment system and the way of present common automation control. We designed manual control variable aeration program and two automatic control subroutine which included thickness grille and pumping station by using WIN 32 software. The program is designed in Siemens STEP 7 V5.5 software development platform and chose the 10 input contacts which are I0.0~I0.7, I1.0~I1.1 and 10 output contact which are Q1.0~Q1.1, Q0.0~Q0.7.This design achieves automatic control and improves the purifying efficiency on the premise of ensuring water quality.

APA, Harvard, Vancouver, ISO, and other styles

25

Molchanov, Oleksandr, Kamil Krpec, and Jiří Horák. "Electrostatic precipitation as a method to control the emissions of particulate matter from small-scale combustion units." Journal of Cleaner Production 246 (February 2020): 119022. http://dx.doi.org/10.1016/j.jclepro.2019.119022.

Full text

APA, Harvard, Vancouver, ISO, and other styles

26

Bobrikov, V. V., L. P. Baranov, and V. A. Kireeva. "A system of automatic control of the operation of electrostatic precipitators for the collection of lignite dust." Chemical and Petroleum Engineering 26, no. 1 (January 1990): 45–47. http://dx.doi.org/10.1007/bf01148161.

Full text

APA, Harvard, Vancouver, ISO, and other styles

27

Behjat, Vahid, Afshin Rezaei-Zare, Issouf Fofana, and Ali Naderian. "Concept Design of a High-Voltage Electrostatic Sanitizer to Prevent Spread of COVID-19 Coronavirus." Energies 14, no. 22 (November 22, 2021): 7808. http://dx.doi.org/10.3390/en14227808.

Full text

Abstract:

In addition to public health measures, including social distancing, masking, cleaning, surface disinfection, etc., ventilation and air filtration can be a key component of a multi-pronged risk mitigation strategy against COVID-19 transmission indoors. Electrostatic precipitators (ESP) have already proved their high performance in fluid filtration, particularly in industrial applications, to control exhaust gas emissions and remove fine and superfine particles from the flowing gas, using high-voltage electrostatic fields and forces. In this contribution, a high-voltage electrostatic sanitizer (ESS), based on the electrostatic precipitation concept, is proposed as a supportive measure to reduce indoor air infection and prevent the spread of COVID-19 coronavirus. The finite element method (FEM) is used to model and simulate the proposed ESS, taking into account three main mechanisms involving in electrostatic sanitization, namely electrostatic field, airflow, and aerosol charging and tracing, which are mutually coupled to each other and occur simultaneously during the sanitization process. To consider the capability of the designed ESS in capturing superfine particles, functional parameters of the developed ESS, such as air velocity, electric potential, and space charge density, inside the ESS are investigated using the developed FEM model. Simulation results demonstrate the ability of the designed ESS in capturing aerosols containing coronavirus, precipitating suspended viral particles, and trapping them in oppositely charged electrode plates.

APA, Harvard, Vancouver, ISO, and other styles

28

Tahir, Hasan Riaz, Benny Malengier, Didier Van Daele, and Lieva Van Langenhove. "Validation of a Platform for the Electrostatic Characterization of Textile." Electronics 11, no. 1 (December 30, 2021): 115. http://dx.doi.org/10.3390/electronics11010115.

Full text

Abstract:

Floor covering samples of different thickness, pile height, pile design, materials, construction methods, and applied finishes were selected for electrostatic characterization with a standard plotter platform and a newly designed digital platform. There is an existing standard ISO 6356 in which the voltage generated by a human walking on the carpet is measured with human involvement under controlled conditions. A walking person performs the original test procedure to generate the electrostatic charge and manually calculates results. In contrast, the newly designed system does not require a person to calculate peaks and valleys for the generated electrostatic charges, which offers advantages in terms of accuracy, consistency, and reproducibility, and eliminates human error. The electronic platform is extended with an automated foot for a fully automated test, called “automatic mode”, that has a fixed capacitive and resistive circuit, in replace of human body resistance, and capacitance that varies from person to person and over time. The procedure includes both the old and new platforms, where the new platform is placed in a “human walking” mode to compare the two and validate the new device. Next, all the floor coverings are tested in automatic mode with the automated foot to compare and validate results. We conclude that the new testing device can fully characterize the electrostatic behavior of textile without the involvement of a human, which offers advantages in terms of accuracy, consistency, and reproducibility.

APA, Harvard, Vancouver, ISO, and other styles

29

Silva, Flavio Vasconcelos da, Regina Lúcia de Andrade dos Santos, Tatiana Lie Fujiki, Manuela Souza Leite, and Ana Maria Frattini Fileti. "Design of automatic control system for the precipitation of bromelain from the extract of pineapple wastes." Ciência e Tecnologia de Alimentos 30, no. 4 (December 2010): 1033–40. http://dx.doi.org/10.1590/s0101-20612010000400031.

Full text

APA, Harvard, Vancouver, ISO, and other styles

30

Zhang, Juan, Wenrong Wu, and Lie Bi. "An automatic approach and grip method of micro-particle in 3D space." International Journal of Modern Physics B 31, no. 07 (March 19, 2017): 1741013. http://dx.doi.org/10.1142/s0217979217410132.

Full text

Abstract:

Micro-particle is hard to be observed as small scale and hard to be gripped as micro-force from substrate, an automatic approach and grip method of micro-particle in the guide of microscopic vision systems is proposed in the paper to grip micro-particle. First, the micro-gripper driven by electrostatic force is introduced and forces in gripping process are analyzed. Second, a micro-assembly robot composed of two microscopic vision systems is established to monitor micro-operation process and to operate micro-particle. Image features of micro-particle and micro-gripper end-effector are extracted by image feature extraction method to calculate relative position of micro-particle and micro-gripper in image space. Last, a movement control strategy in 3D space based on image Jacobian matrix is studied to control micro-gripper approach and align with micro-particle. Experimental results verified the effectiveness of proposed methods.

APA, Harvard, Vancouver, ISO, and other styles

31

Johnston, Arthur M., G. W. Hughson, A. D. Jones, and J. H. Vincent. "A Laboratory Pilot Study to Investigate the Feasibility of Localized Electrostatic Precipitation for Dust Control in Industrial Workplaces." Applied Industrial Hygiene 3, no. 11 (November 1988): 321–25. http://dx.doi.org/10.1080/08828032.1988.10389865.

Full text

APA, Harvard, Vancouver, ISO, and other styles

32

Båserud, Line, Cristian Lussana, Thomas N. Nipen, Ivar A. Seierstad, Louise Oram, and Trygve Aspelien. "TITAN automatic spatial quality control of meteorological in-situ observations." Advances in Science and Research 17 (July 22, 2020): 153–63. http://dx.doi.org/10.5194/asr-17-153-2020.

Full text

Abstract:

Abstract. In science, poor quality input data will invariably lead to faulty conclusions, as in the spirit of the saying “garbage in, garbage out”. Atmospheric sciences make no exception and correct data is crucial to obtain a useful representation of the real world in meteorological, climatological and hydrological applications. Titan is a computer program for the automatic quality control of meteorological data that has been designed to serve real-time operational applications that process massive amounts of observations measured by networks of automatic weather stations. The need to quality control third-party data, such as citizen observations, within a station network that is constantly changing was an important motivation that led to the development of Titan. The quality control strategy adopted is a sequence of tests, where several of them utilize the expected spatial consistency between nearby observations. The spatial continuity can also be evaluated against independent data sources, such as numerical model output and remote sensing measurements. Examples of applications of Titan for the quality control of near-surface hourly temperature and precipitation over Scandinavia are presented. In the case of temperature, this specific application has been integrated into the operational production chain of automatic weather forecasts at the Norwegian Meteorological Institute (MET Norway). Titan is an open source project and it is made freely available for public download. One of the objectives of the Titan project is to establish a community working on common tools for automatic quality control, and the Titan program represents a first step in that direction for MET Norway. Further developments are necessary to achieve a solution that satisfies more users, for this reason we are currently working on transforming Titan into a more flexible library of functions.

APA, Harvard, Vancouver, ISO, and other styles

33

Otop, Irena, Jan Szturc, Katarzyna Ośródka, and Piotr Djaków. "Automatic quality control of telemetric rain gauge data for operational applications at IMGW-PIB." ITM Web of Conferences 23 (2018): 00028. http://dx.doi.org/10.1051/itmconf/20182300028.

Full text

Abstract:

The automatic procedure of real-time quality control (QC) of telemetric rain gauge measurements (G) has been developed to produce quantitative precipitation estimates mainly for the needs of operational hydrology. The developed QC procedure consists of several tests: gross error detection, a range check, a spatial consistency check, a temporal consistency check, and a radar and satellite conformity check. The output of the procedure applied in real-time is quality index QI(G) that quantitatively characterised quality of each individual measurement. The QC procedure has been implemented into operational work at the Institute of Meteorology and Water Management since 2016. However, some elements of the procedure are still under development and can be improved based on the results and experience collected after about two years of real-time work on network of telemetric rain gauges

APA, Harvard, Vancouver, ISO, and other styles

34

Zhang, Boxin, Indu Aravind, Sisi Yang, Sizhe Weng, Bofan Zhao, Christi Schroeder, William Schroeder, et al. "Plasma-enhanced electrostatic precipitation of diesel exhaust particulates using nanosecond high voltage pulse discharge for mobile source emission control." Science of The Total Environment 851 (December 2022): 158181. http://dx.doi.org/10.1016/j.scitotenv.2022.158181.

Full text

APA, Harvard, Vancouver, ISO, and other styles

35

Udhare, Atul. "Automatic Rain Gauge (Sensor Based) for Rainfall Calculation." International Journal for Research in Applied Science and Engineering Technology 9, no. VII (July 25, 2021): 2297–300. http://dx.doi.org/10.22214/ijraset.2021.36891.

Full text

Abstract:

Theoretical Rainfall estimation framework is a helpful instrument in climate estimation framework. The programmed Rain check has been effectively evolved by meteorological, climatological, and geophysical office. In tropical country, for example, India for the most part Jammu and Kashmir, precipitation estimation for rural and climate determining framework is vital. Testing related tippingcontainer (TB) downpour check estimations have huge mistakes for brief time frame assessment. In this paper, a stable electronic downpour measure situation with complete information control is planned and created. This venture utilized generally electronic gadgets to make our task more programmed and reasonable to record the information plainly and most precisely. The framework estimates rainfalls precisely, saves the information perusing and shows explicit determined for show. Framework gives total water estimation situation along with complete information control component. The framework is extremely simple to be dealt with in each circumstance. The estimation is extremely high exact and effectively detectible. This presence of these instruments can substitute the ordinary downpour check perception framework or the normal downpour measures utilized in india and it's regions. It's trusted that the replacement of normal downpour measures can produce more benefits including organization, cost, and the straightforwardness of activity and exactness information. This instrument will help onlooker who have not explicit schooling in meteorology or climatology.

APA, Harvard, Vancouver, ISO, and other styles

36

Barausov, V. A., Vl P. Bubnov, Sh Kh Sultonov, and D. V. Barausov. "ALGORITHMS OF THE CONTROL PROGRAM OF AUTOMATIC CLEANING SYSTEMS OF THE TURNOUTS BASED ON THE SENSOR FOR DETERMINING ICE OR SNOW ON THE CONTROLLED SURFACE." Automation on Transport 7, no. 2 (June 2021): 231–51. http://dx.doi.org/10.20295/2412-9186-2021-7-2-231-251.

Full text

Abstract:

The structure of an automatic system for cleaning turnouts is considered, the main advantages and disadvantages of precipitation sensors of existing automatic systems for cleaning turnouts are analyzed. It is concluded that it is necessary to develop an advanced system based on a sensor for de- tecting ice or snow on a controlled surface. The developed block diagram of the formation of control actions of the system for detecting icing or snow on the controlled surface is presented. An algorithm is given for its technical implementation, as well as for measuring the anticipatory control of the process of electric heating of the controlled surface of the switches. The results of simulation of the device and method for determining ice or snow on a controlled surface in the Matlab Simulink environment are presented.

APA, Harvard, Vancouver, ISO, and other styles

37

Wang, Qiang Gao, Yuan Yuan Liu, Da Li Liu, Chang Juan Jing, and Qing Xi Hu. "A New Feeding Device of Electrospinning Design for the Micro-Structure of Bone Scaffold Prototyping." Advanced Materials Research 211-212 (February 2011): 1041–45. http://dx.doi.org/10.4028/www.scientific.net/amr.211-212.1041.

Full text

Abstract:

In order to solve the problem that bone cells can not adhere to the pore wall, the paper introduces a new method that combines RP method with electrostatic spinning method is used for the preparation of a comprehensive new bone scaffold technology, and pays close attention on the automatic control of process parameters, the feeding speed. According to the model of feed speed and the diameter of nano-fibers, a theoretical guidance is given to the real-time control of feed speed, and a new feeding device, including the configuration software iFIX, a microcontroller, a sensor and stepping motor, is presented. It can give a real-time effective control of the feed speed, which provides a theoretical and technological basis for the quality of scaffolds prototyping.

APA, Harvard, Vancouver, ISO, and other styles

38

Zhang, Lihui, Helei Cui, Hongli Li, Feng Han, Yaqiu Zhang, and Wenfu Wu. "Parameters Online Detection and Model Predictive Control during the Grain Drying Process." Mathematical Problems in Engineering 2013 (2013): 1–7. http://dx.doi.org/10.1155/2013/924698.

Full text

Abstract:

In order to improve the grain drying quality and automation level, combined with the structural characteristics of the cross-flow circulation grain dryer designed and developed by us, the temperature, moisture, and other parameters measuring sensors were placed on the dryer, to achieve online automatic detection of process parameters during the grain drying process. A drying model predictive control system was set up. A grain dry predictive control model at constant velocity and variable temperature was established, in which the entire process was dried at constant velocity (i.e., precipitation rate per hour is a constant) and variable temperature. Combining PC with PLC, and based on LabVIEW, a system control platform was designed.

APA, Harvard, Vancouver, ISO, and other styles

39

Bae, Jeong-Ho, and Ki-Hong Min. "Forecast Characteristics of Radar Data Assimilation Based on the Scales of Precipitation Systems." Remote Sensing 14, no. 3 (January 27, 2022): 605. http://dx.doi.org/10.3390/rs14030605.

Full text

Abstract:

Radar data with high spatiotemporal resolution and automatic weather station (AWS) data are used in the data assimilation experiment to improve the precipitation forecast of a numerical model. The numerical model considered in this study is the Weather Research and Forecasting (WRF) model with double-moment 6-class microphysics scheme (WDM6). We calculated the radar equivalent reflectivity factor using high resolution WRF and compared it with radar observations in South Korea. To compare the precipitation forecast characteristics of the three-dimensional variational (3D-Var) assimilation of radar data, four experiments were performed based on the scales of precipitation systems. Comparison of the 24 h accumulated rainfall with surface observation data, contoured frequency by altitude diagram (CFAD), time–height cross sections (THCS), and vertical hydrometeor profiles was used to evaluate the accuracy of the simulation of precipitation. The model simulations were performed with and without 3D-VAR radar reflectivity, radial velocity and AWS assimilation for two mesoscale convective cases and two synoptic scale cases. The combined effect of the radar and AWS data assimilation experiment improved the location of the precipitation area and rainfall intensity compared to the control run. There is a noticeable scale dependence in the improvement of precipitation systems. Improvements in simulating mesoscale convective systems were larger compared to synoptically driven precipitation systems.

APA, Harvard, Vancouver, ISO, and other styles

40

Škrk, Nina, Roberto Serrano-Notivoli, Katarina Čufar, Maks Merela, Zalika Črepinšek, Lučka Kajfež Bogataj, and Martín de Luis. "SLOCLIM: a high-resolution daily gridded precipitation and temperature dataset for Slovenia." Earth System Science Data 13, no. 7 (July 29, 2021): 3577–92. http://dx.doi.org/10.5194/essd-13-3577-2021.

Full text

Abstract:

Abstract. We present a new publicly available daily gridded dataset of maximum and minimum temperature and precipitation data covering the whole territory of Slovenia from 1950 to 2018. It represents the great variability of climate at the crossroads between the Mediterranean, Alpine and continental climatic regimes with altitudes between 0–2864 m a.s.l. We completely reconstructed (quality control and gap filling) the data for the three variables from 174 observatories (climatological, precipitation and automatic stations) with the original records all over the country. A comprehensive quality control process based on the spatial coherence of the data was applied to the original dataset, and the missing values were estimated for each day and location independently. Using the filled data series, a grid of 1×1 km spatial resolution with 20 998 points was created by estimating daily temperatures (minimum and maximum) and precipitation, as well as their corresponding uncertainties at each grid point. In order to show the potential applications, four daily temperature indices and two on precipitation were calculated to describe the spatial distribution of (1) the absolute maximum and minimum temperature, (2) the number of frost days, (3) the number of summer days, (4) the intensity of precipitation and (5) the maximum number of consecutive dry days. The use of all the available information, the complete quality control and the high spatial resolution of the grid allowed for an accurate estimate of precipitation and temperature that represents a precise spatial and temporal distribution of daily temperatures and precipitation in Slovenia. The SLOCLIM dataset is publicly available at https://doi.org/10.5281/zenodo.4108543 and http://www.sloclim.eu (last access: 10 June 2021) and can be cited as Škrk et al. (2020).

APA, Harvard, Vancouver, ISO, and other styles

41

Rigo, Tomeu, Maria Carmen Llasat, and Laura Esbrí. "The Results of Applying Different Methodologies to 10 Years of Quantitative Precipitation Estimation in Catalonia Using Weather Radar." Geomatics 1, no. 3 (July 18, 2021): 347–68. http://dx.doi.org/10.3390/geomatics1030020.

Full text

Abstract:

The single polarization C-Band weather radar network of the Meteorological Service of Catalonia covers the entire region (32,000 km2), which allows it to apply a series of corrections that improve preliminary estimations of the rainfall field (hourly and daily). In addition, an automatic re-processing using automatic weather stations helps to incorporate ground-based information. The last process of the quantitative precipitation estimation (QPE) is running the end-product again eight days later, when the data have been reviewed and corrected in the case of detecting anomalies in the radar or gauge data. These corrections are applied operationally, with the fields generated and stored automatically. The QPE fields are generated in the GeoTIFF format, allowing easy use with multiple applications and simplifying processes such as quality control. In this way, the analysis of a 10 year period of GeoTIFF QPE daily data compared with ground rainfall values is introduced. The results help to understand different points regarding the functioning of the network such as the dependance on the type of precipitation and the seasonality. In addition, the description of a heavy rainfall episode (22 October 2019) shows the variations and improvements in the different products. The main conclusions refer to how using GeoTIFF combined with point data (rain gauges), it is possible to ensure simple but effective quality control of an operational radar network.

APA, Harvard, Vancouver, ISO, and other styles

42

Schamm, K., M. Ziese, A. Becker, P. Finger, A. Meyer-Christoffer, U. Schneider, M. Schröder, and P. Stender. "Global gridded precipitation over land: a description of the new GPCC First Guess Daily product." Earth System Science Data Discussions 6, no. 2 (August 9, 2013): 435–64. http://dx.doi.org/10.5194/essdd-6-435-2013.

Full text

Abstract:

Abstract. This paper describes the new "First Guess Daily" product of the Global Precipitation Climatology Centre (GPCC). The new product gives an estimate of the global daily precipitation gridded at a spatial resolution of 1° latitude by longitude. It is based on rain gauge data reported in near real-time via the Global Telecommunication System (GTS) and available about three to five days after the end of each observation month. In addition to the gridded daily precipitation totals in mm day−1, the standard deviation in mm day−1, the Kriging interpolation error in % and the number of measurements per grid cell are also encoded into the monthly netCDF product file and provided for all months since January 2009. Prior to their interpolation the measured precipitation values undergo a preliminary automatic quality control. For the calculation of the areal mean of the grid, anomalies are interpolated with ordinary block Kriging. This approach allows for a near real-time release. However, the purely GTS-based data processing lacks an intensive quality control as well as a high data density. Therefore the product is denoted as "First Guess", and DOI referenced under doi:10.5676/DWD_GPCC/FG_D_100. Besides the "First Guess Daily" product, two further products are under developement at GPCC ("Full Data Daily" and a merged satellite-gauge product), which will be based on all available daily data that have undergone a strict quality control. All GPCC products are available free of charge and provided via the GPCC webpage: ftp://ftp-anon.dwd.de/pub/data/gpcc/html/download_gate.html.

APA, Harvard, Vancouver, ISO, and other styles

43

Golomolzina, Diana Rashidovna, Maxim Alexandrovich Gorodnichev, Evgeny Andreevich Levin, Alexander Nikolaevich Savostyanov, Ekaterina Pavlovna Yablokova, Arthur C. Tsai, Mikhail Sergeevich Zaleshin, et al. "Advanced Electroencephalogram Processing." International Journal of E-Health and Medical Communications 5, no. 2 (April 2014): 49–69. http://dx.doi.org/10.4018/ijehmc.2014040103.

Full text

Abstract:

The study of electroencephalography (EEG) data can involve independent component analysis and further clustering of the components according to relation of the components to certain processes in a brain or to external sources of electricity such as muscular motion impulses, electrical fields inducted by power mains, electrostatic discharges, etc. At present, known methods for clustering of components are costly because require additional measurements with magnetic-resonance imaging (MRI), for example, or have accuracy restrictions if only EEG data is analyzed. A new method and algorithm for automatic clustering of physiologically similar but statistically independent EEG components is described in this paper. Developed clustering algorithm has been compared with algorithms implemented in the EEGLab toolbox. The paper contains results of algorithms testing on real EEG data obtained under two experimental tasks: voluntary movement control under conditions of stop-signal paradigm and syntactical error recognition in written sentences. The experimental evaluation demonstrated more than 90% correspondence between the results of automatic clustering and clustering made by an expert physiologist.

APA, Harvard, Vancouver, ISO, and other styles

44

López-Espinoza, Erika D., Oscar A. Fuentes-Mariles, Dulce R. Herrera-Moro, Octavio Gómez-Ramos, David A. Novelo-Casanova, and Jorge Zavala-Hidalgo. "Daily Precipitation Data for the Mexico City Metropolitan Area from 1930 to 2015." Data 7, no. 7 (June 29, 2022): 88. http://dx.doi.org/10.3390/data7070088.

Full text

Abstract:

The Metropolitan Zone of Mexico City, as well as the associated basin, includes the territories of Mexico City, some municipalities of the State of Mexico and the state of Hidalgo. In addition, this area is the most densely populated in Mexico. The region is influenced by mid-latitude and tropical weather systems and is vulnerable to extreme hydrometeorological events. In this context, we developed a dataset from the records of 136 geolocated sites that includes daily precipitation data from the CLImate COMputing (CLICOM) project and the Mexico City Water System. The data spans the period from 1930 to 2015 for the rainy months (June–October) from stations with records of 20 or more years. In each recording site, automatic and manual data quality control were performed to verify the consistency of the daily precipitation data. We believe that our highly dense precipitation dataset will be useful for climate, trend and extreme events analysis. Additionally, the data will allow validating simulations of numerical atmospheric models. The dataset is public, and it was previously used in other research to determine areas susceptible to flooding due to heavy rain events and to develop a web mapping application of daily precipitation data.

APA, Harvard, Vancouver, ISO, and other styles

45

Ruan, Zhihu, Xukai Ding, Zhengcheng Qin, Jia Jia, and Hongsheng Li. "Automatic Mode-Matching Method for MEMS Disk Resonator Gyroscopes Based on Virtual Coriolis Force." Micromachines 11, no. 2 (February 18, 2020): 210. http://dx.doi.org/10.3390/mi11020210.

Full text

Abstract:

An automatic mode-matching method for MEMS (Micro-electromechanical Systems) disk resonator gyroscopes (DRGs) based on virtual Coriolis force is presented in this paper. For this mode-matching method, the additional tuning electrodes are not required to be designed, which simplifies the structure design. By using the quadratic relationship between the driving voltage and the electrostatic force, the virtual Coriolis force is obtained by applying an AC voltage whose frequency is half of the driving mode resonant frequency to the sense electrode. The phase difference between the virtual Coriolis force and the sense output signal is used for mode-matching. The structural characteristics and electrode distribution of the DRG are briefly introduced. Moreover, the mode-matching theories of the DRG are studied in detail. The scheme of the mode-matching control system is proposed. Simultaneously, the feasibility and effectiveness of the mode-matching method are verified by system simulation. The experimental results show that under the control of mode-matching at room temperature, the bias instability is reduced from 30.7575 ° /h to 2.8331 ° /h, and the Angle Random Walk (ARW) decreases from 1.0208 ° / h to 0.0524 ° / h . Compared with the mode mismatch condition, the ARW is improved by 19.48 times.

APA, Harvard, Vancouver, ISO, and other styles

46

Nermoen, Anders, Reidar Inge Korsnes, Eirik Vika Storm, Trond Stødle, Merete Vadla Madland, and Ida Lykke Fabricius. "Incorporating electrostatic effects into the effective stress relation — Insights from chalk experiments." GEOPHYSICS 83, no. 3 (May 1, 2018): MR123—MR135. http://dx.doi.org/10.1190/geo2016-0607.1.

Full text

Abstract:

Which forces are responsible for holding highly porous chalks together? We use the effective stress to quantify the electrostatic effects around particle contacts originating from the adsorption of ions onto charged mineral surfaces. The induration of chalk indicates that it is held together by contact cement, where planar crystal contacts allow the action of short-ranged adhesive Van der Waals forces. At particle distances exceeding a few nanometers, recent studies have indicated electrostatic repulsion between water-embedded adjacent particles. The magnitude of the repelling force depends, among other parameters, upon temperature and brine composition. Our premise is that by perturbing the electrostatic forces at the particle level, we can control the mechanical behavior of chalk samples tested in triaxial cells. We report the results of an experimental series, investigating how the mechanical strength and stiffness varied among samples saturated with four different brines, tested at two temperatures, and tested directly or after aging for three weeks at high temperature. We associate stiffness with bulk modulus and strength with the stress at yield. Systematic softening and weakening is observed, especially when the pore fluid is sulfate bearing, as well as for some high-temperature experiments and for aged samples. However, softening and weakening are not totally correlated, and neither brine composition, temperature, nor aging can alone dictate the mechanical behavior of the chalk — a combination is required to predict the chalk stiffness and strength. To obtain a coherent description of our experimental results, we estimated the electrostatic stress arising from ion adsorption and found it unnecessary for these experiments to postulate significant dissolution or precipitation-related changes to the rock frame.

APA, Harvard, Vancouver, ISO, and other styles

47

Schamm, K., M. Ziese, A. Becker, P. Finger, A. Meyer-Christoffer, U. Schneider, M. Schröder, and P. Stender. "Global gridded precipitation over land: a description of the new GPCC First Guess Daily product." Earth System Science Data 6, no. 1 (January 27, 2014): 49–60. http://dx.doi.org/10.5194/essd-6-49-2014.

Full text

Abstract:

Abstract. This paper describes the new First Guess Daily product of the Global Precipitation Climatology Centre (GPCC). The new product gives an estimate of the global daily precipitation gridded at a spatial resolution of 1° latitude by 1° longitude. It is based on rain gauge data reported in near-real time via the Global Telecommunication System (GTS) and available about three to five days after the end of each observation month. In addition to the gridded daily precipitation totals in mm day−1, the standard deviation in mm day−1, the kriging interpolation error in % and the number of measurements per grid cell are also encoded into the monthly netCDF product file and provided for all months since January 2009. Prior to their interpolation, the measured precipitation values undergo a preliminary automatic quality control. For the calculation of the areal mean of the grid, anomalies are interpolated with ordinary block kriging. This approach allows for a near-real-time release. Therefore, the purely GTS-based data processing lacks an intensive quality control as well as a high data density and is denoted as First Guess. The daily data set is referenced under doi:10.5676/DWD_GPCC/FG_D_100. Two further products, the Full Data Daily and a merged satellite-gauge product, are currently under development at Deutscher Wetterdienst (DWD). These additional products will not be available in near-real time, but based on significantly more and strictly quality controlled observations. All GPCC products are provided free of charge via the GPCC webpage: ftp://ftp-anon.dwd.de/pub/data/gpcc/html/download_gate.html.

APA, Harvard, Vancouver, ISO, and other styles

48

Lotter, L. H., and A. R. Pitman. "The Usefulness of On-Line Monitoring in Effecting Savings in Combined Biological and Chemical Removal of Phosphorus in Activated Sludge Plants." Water Science and Technology 28, no. 11-12 (December 1, 1993): 539–48. http://dx.doi.org/10.2166/wst.1993.0694.

Full text

Abstract:

On-line analyzers to monitor the effluent levels of ammonia and phosphate have been installed at all four nutrient removal activated sludge plants in Johannesburg. The data from these instruments is transferred to a SCADA system for control purposes. The on-line system is supplemented by laboratory data, which is stored on a separate computer system. A combination of this data is used for routine operational control. Dissolved oxygen probes are installed in the aerobic reactors of all plants and are used for aeration control. Automatic aeration control has recently been installed at one of the plants. In this paper some experience with on-line monitoring is discussed in terms of its usefulness and cost savings achieved. Savings of 1 million US $ in the purchase of phosphate precipitation chemicals have been achieved in the current financial year as a result of more efficient operational control.

APA, Harvard, Vancouver, ISO, and other styles

49

Rhoades, Charles B., and Ralph T. White. "Mainstream Smoke Collection by Electrostatic Precipitation for Acid Dissolution in a Microwave Digestion System Prior to Trace Metal Determination." Journal of AOAC INTERNATIONAL 80, no. 6 (November 1, 1997): 1320–31. http://dx.doi.org/10.1093/jaoac/80.6.1320.

Full text

Abstract:

Abstract A method is described for collection and preparation of mainstream smoke condensate from cigarettes for determination of trace metal constituents. A sample of mainstream smoke was collected from 300 cigarettes in a final volume of 25 mL. Extremely clean laboratory conditions during sample preparation were essential to avoid contamination and improve precision and accuracy for trace element determination. The clean laboratories maintained a positive pressure of HEPA-filtered air with constant temperature and humidity control. Mainstream cigarette smoke was collected by electrostatic precipitation (EP) on a modified rotary smoking machine located in a wooden CORESTA cabinet. The EP unit was equipped with a high tension generator supplying 17.5 kV to a tungsten electrode followed by 2 secondary acid traps. Samples were collected under 2 smoking regimens: FTC (35 mL puff volumes, one puff every 60 s, and puff duration 2 s) and “Extreme” (75 mL puff volumes, one puff every 35 s, puff duration 2 s). Condensate was extracted from collection tubes with methanol into Teflon microwave digestion vessels and evaporated in an environmental evaporation chamber (EEC). The EEC provided an ultraclean environment for sample evaporation and predigestion steps that eliminated most of the sample matrix. The remainder was decomposed in a programmable closed vessel microwave digestion system. Digested sample solutions were analyzed by graphite furnace atomic absorption spectrometry and inductively coupled plasma optical emission spectrometry for aluminum, arsenic, cadmium, chromium, nickel, and silicon.

APA, Harvard, Vancouver, ISO, and other styles

50

Kim, Park Sa, and Hwan-Jin Song. "Usefulness of Automatic Hyperparameter Optimization in Developing Radiation Emulator in a Numerical Weather Prediction Model." Atmosphere 13, no. 5 (April 30, 2022): 721. http://dx.doi.org/10.3390/atmos13050721.

Full text

Abstract:

To improve the forecasting accuracy of a radiation emulator in a weather prediction model over the Korean peninsula, the learning rate used in neural network training was automatically optimized using the Sherpa. The Sherpa experiment results were compared with two control simulation results using learning rates of 0.0001 and 1 for different batch sizes (full to 500). In the offline evaluation, the Sherpa results showed significant improvements in predicting longwave/shortwave heating rates and fluxes compared to the lowest learning rate results, whereas the improvements compared to the highest learning rate were relatively small because the optimized values by the Sherpa were 0.4756–0.6656. The online evaluation results over one month, which were linked with the weather prediction model, demonstrated the usefulness of Sherpa on a universal performance for the radiation emulator. In particular, at the full batch size, Sherpa contributed to reducing the one-week forecast errors for longwave/shortwave fluxes, skin temperature, and precipitation by 39–125%, 137–159%, and 24–26%, respectively, compared with the two control simulations. Considering the widespread use of parallel learning based on full batch, Sherpa can contribute to producing robust results regardless of batch sizes used in neural network training for developing radiation emulators.

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Electrostatic precipitation Automatic control'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles