The vibration of the charging belt in an electrostatic accelerator has intense influ- ences on the accelerator operation. A calculating model was set up in this paper to study the belt vibration. The results show that...The vibration of the charging belt in an electrostatic accelerator has intense influ- ences on the accelerator operation. A calculating model was set up in this paper to study the belt vibration. The results show that the belt tension, belt velocity and belt current all contribute to the belt vibration. There is an optimal relationship among the three factors by which the belt would run most smoothly. There exists a minimum value of optimal tension for various belt velocities. The vibrating frequency of the is generally around several Hz.展开更多
Electric fields induced by ring and pin electrodes in electrostatic charged powder sprayingtechnique are analysed. The fundamental formulae to deseribe these fields have been built up. Theseformulae could be used to d...Electric fields induced by ring and pin electrodes in electrostatic charged powder sprayingtechnique are analysed. The fundamental formulae to deseribe these fields have been built up. Theseformulae could be used to design electrostatic charged podwer spraying system. The chargingeffectiveness of ring and pin electrode is experimentally investigated and compared each other. Theperformance of ring electrode is better than that of pin electrode.展开更多
The aim of this paper is to study the behaviour of bipolar corona with a dual parallel corona bar and a metallic plate. The experimental results show that under otherwise identical conditions, the discharge depends st...The aim of this paper is to study the behaviour of bipolar corona with a dual parallel corona bar and a metallic plate. The experimental results show that under otherwise identical conditions, the discharge depends strongly on the electrode separation between the bars. By investigating various separations, the corona regime can be divided into three regions: independent, shunted, and shorted. The criterion for eliminating electrostatic charge without over compensation is also given.展开更多
In verifying antiretroviral efficacy of a Nigerian broad spectrum antiviral medicine (Antivirt<span style="white-space:nowrap;"><sup>®</sup></span>), the Nigerian Institute o...In verifying antiretroviral efficacy of a Nigerian broad spectrum antiviral medicine (Antivirt<span style="white-space:nowrap;"><sup>®</sup></span>), the Nigerian Institute of Medical Research certified it safe by toxicological test on laboratory animals, before commencing treatment of three HIV/AIDS patients whose viral loads varied widely (millions, hundreds of thousands and thousands). To overcome errors associated with such wide differences in subject-classes, percentages of viral load-reductions were calculated instead of comparing their viral loads. After first month of the Antivirt<span style="white-space:nowrap;"><sup>®</sup></span>-treatment, means of ranked viral loads of the patients significantly (P ≤ 0.05) increased from 10.00 ± 7.21 to 11.30 ± 5.51 (-41.03% infection-reduction rate) instead of reducing. From second month of the trial, their viral loads started to reduce, continuously, so that their infection-reduction rates have been increasing from that -41.03%, to -38.22% in the second month;23.98% in the third month;31.76% in the fourth month and 64.12% after the fifth month.展开更多
Two electrically charged rings of different sizes are assembled along their common vertical symmetry axis through their centers. The bottom ring is secured on a horizontal support while the top one is loose. For a set...Two electrically charged rings of different sizes are assembled along their common vertical symmetry axis through their centers. The bottom ring is secured on a horizontal support while the top one is loose. For a set of practical values characterizing the charged rings we envision a scenario where the mutual electric repulsion between the rings and the weight of the top ring results in stable nonlinear oscillations. To quantify the characteristics of the oscillations, we utilize a Computer Algebra System specifically <em>Mathematica</em> [1]. We accompany the analysis with a simulation for a comprehensive visual understanding.展开更多
<i>COVID</i>-19 <i>virus</i> has positive electrical charges. So, particles that are negatively charged would, by opposite charges-electrostatic attraction, inhibit its replication’s first sta...<i>COVID</i>-19 <i>virus</i> has positive electrical charges. So, particles that are negatively charged would, by opposite charges-electrostatic attraction, inhibit its replication’s first stage (attachment to cells) and mop its extra-cellular particles. Positively charged particles would similarly mop/destroy cells it infects because unlike healthy cells which are neutral, infected/tumor cells have negative electrical charges. <i>Nanoparticles</i> (0.96 nm) of Aluminum-magnesium silicate (AMS), WHO-approved medicine/adjuvant have both negative and positive charged ends. As adjuvant it improves antimicrobials’ efficacies (clearing secondary infections) while as silicate it enhances immunity. By inhibiting viral replication;mopping extra-cellular viruses/abnormal cells;clearing secondary infections;enhancing immunity, AMS terminates viral-infections/abnormal cells’ metastases. Natural AMS has impurities and its deposits are not found in Nigeria. So, Aluminum silicate and Magnesium silicate (WHO-approved medicines) were used for <i>Medicinal synthetic AMS</i> {MSAMS: Al<sub>4</sub> (SiO<sub>4</sub>)<sub>3</sub> + 3Mg<sub>2</sub>SiO<sub>4</sub> → 2Al<sub>2</sub>Mg<sub>3</sub> (SiO<sub>4</sub>)<sub>3</sub>}. Since AMS is un-absorbable, dextrose monohydrate is incorporated in MSAMS-formulations to convey its <i>Nanoparticles</i> into blood for circulation to all organs/tissues (active-transportation). The MSAMS achieved quick cure (within 3 days) of all four COVID-19 patients used for its first-phase trial (one in Nigeria, two in Cameroon, one in Tanzania).展开更多
In solid processing systems, electrostatic problems are commonly observed for granules of various shapes. However, a complete understanding of the basic dependence of electrostatic charge generation on particle shape ...In solid processing systems, electrostatic problems are commonly observed for granules of various shapes. However, a complete understanding of the basic dependence of electrostatic charge generation on particle shape has yet to be established. This observation motivated the present study on examining the effect of granular shape on electrostatics. In this study, polyvinyl chloride (PVC) granules (diameter 1.1-4.1 ram, in the shape of a triangle or trapezium) were first discharged to remove any residual charges and sub- sequently their electrostatic charging characteristics were studied by allowing a granule to slide along a pipe wall. Several factors such as granular front-facing angle, length-ratio, sliding area, sliding orienta- tion, sliding times, and relative humidity were considered when studying their effects on the electrostatic charging of granules. It was found that triangular granules with smaller front-facing angles tended to generate more electrostatic charge. The amount of electrostatic charge increased with granular length- ratio and sliding area but decreased with humidity. In addition, granular sliding in the orientation of the front-facing angle (for triangular granules) or the short side (for trapezoidal granules) generated more electrostatic charge than that in the orientation of the long side. For both granule shapes, the elec- trostatic charge increased with granular sliding times and reached a saturated state after around 8-9 sliding movements. The saturated electrostatic charge increased with either granular length ratio or sliding area.展开更多
Electrostatic phenomena are commonly observed in the processing of solids. However. the working mech- anism of electrostatic charge generation for single granules and particularly, their electrostatic equilibria have ...Electrostatic phenomena are commonly observed in the processing of solids. However. the working mech- anism of electrostatic charge generation for single granules and particularly, their electrostatic equilibria have not been properly understood. In this work, repeated-sliding charging experiments with single granules were investigated for their electrostatic generation particularly from the perspective of tribo- electrification equilibrium. Factors including granule length-ratio, sliding face shape, sliding times, sliding area, sliding velocity, front-facing edge, and sliding-plate inclined-angle were found to have an obvious effect on granule charge generation. Length-ratio and sliding area have significant effects as the gran- ules evolved toward an equilibrium state. Equilibrium charge is suggested as a variable expressing the charging propensity of the material. In addition, under the same working conditions, a semi-cylindrical granule generates greater charge than a rectangular granule.展开更多
To develop a depth filter based on the electrostatic adsorption principle, positively charged microporous ceramic membrane was prepared from a diatomaceous earth ceramic membrane.The internal surface of the highly por...To develop a depth filter based on the electrostatic adsorption principle, positively charged microporous ceramic membrane was prepared from a diatomaceous earth ceramic membrane.The internal surface of the highly porous ceramic membrane was coated with uniformly distributed electropositive nano-Y2O3 coating. The dye removal performance was evaluated through pressurized filtration tests using Titan Yellow aqueous solution. It showed that positively charged microporous ceramic membrane exhibited a flow rate of 421 L/(m^2·hr) under the trans-membrane pressure of 0.03 bar. Moreover it could effectively remove Titan Yellow with feed concentration of 10 mg/L between pH 3 to 8. The removal rate increased with the enhancement of the surface charge properties with a maximum rejection of 99.6%. This study provides a new and feasible method of removing organic dyes in wastewater. It is convinced that there will be a broad market for the application of charged ceramic membrane in the field of dye removal or recovery from industry wastewater.展开更多
The adsorption of weak polybase on oppositely charged planar surfaces has been investigated numerically by using the self-consistent field theory(SCFT). Particular attention was paid to the interplay of monomer-surf...The adsorption of weak polybase on oppositely charged planar surfaces has been investigated numerically by using the self-consistent field theory(SCFT). Particular attention was paid to the interplay of monomer-surface electrostatic and non-electrostatic interactions in the adsorption behaviors of weak polybase. In this study, the strength of monomer-surface non-electrostatic interactions was set to be no more than the thermal energy kBT. It was found from the numerical study that in the regime of low surface charge density of the substrate and low p H or high bulk degree of ionization, both the screeningenhanced and screening-reduced salt effects emerge. On the contrary, in the opposite regime, only the screening-reduced salt effect was observed. Moreover, the overall charge neutrality inside the adsorption layer was analyzed. The underlying mechanism governing the adsorption behaviors of weak polybase on oppositely charged surfaces was elucidated.展开更多
Na-rich birnessite(NRB) was synthesized by a simple synthesis method and used as a high-efficiency adsorbent for the removal of ammonium ion(NH+4) from aqueous solution.In order to demonstrate the adsorption perf...Na-rich birnessite(NRB) was synthesized by a simple synthesis method and used as a high-efficiency adsorbent for the removal of ammonium ion(NH+4) from aqueous solution.In order to demonstrate the adsorption performance of the synthesized material,the effects of contact time,pH,initial ammonium ion concentration,and temperature were investigated.Adsorption kinetics showed that the adsorption behavior followed the pseudo second-order kinetic model.The equilibrium adsorption data were fitted to Langmuir and Freundlich adsorption models and the model parameters were evaluated.The monolayer adsorption capacity of the adsorbent,as obtained from the Langmuir isotherm,was 22.61 mg NH+4-N/g at283 K.Thermodynamic analyses showed that the adsorption was spontaneous and that it was also a physisorption process.Our data revealed that the higher NH+4adsorption capacity could be primarily attributed to the water absorption process and electrostatic interaction.Particularly,the high surface hydroxyl-content of NRB enables strong interactions with ammonium ion.The results obtained in this study illustrate that the NRB is expected to be an effective and economically viable adsorbent for ammonium ion removal from aqueous system.展开更多
The behavior of particles impacting the surface of a charged droplet involves adhesion, rebound, and submersion. In the present study, a numerical model for simulating particle impacts on charged droplets is presented...The behavior of particles impacting the surface of a charged droplet involves adhesion, rebound, and submersion. In the present study, a numerical model for simulating particle impacts on charged droplets is presented that takes into account the various impact modes. With the droplet considered as a solid boundary, the criterion for rebounding is that the particle's impact angle is 〈85°. The simulated trajecto- ries of the particles are verified by comparing with experimental data for low-velocity particles to assess the reliability of the model. For impact angles 〉85°, particles undergo three distinct modes depending on normal impact velocities. The critical velocity of adhesion/rebound and rebound/submersion is used to identify the mode that the particles are undergoing. The criteria are also verified by comparing with ana- lytical data. The results show that the impact angle of particles increases with increasing Coulomb number and decreases dramatically with increasing Stokes number, both of which lead to a high probability for particle rebound.展开更多
文摘The vibration of the charging belt in an electrostatic accelerator has intense influ- ences on the accelerator operation. A calculating model was set up in this paper to study the belt vibration. The results show that the belt tension, belt velocity and belt current all contribute to the belt vibration. There is an optimal relationship among the three factors by which the belt would run most smoothly. There exists a minimum value of optimal tension for various belt velocities. The vibrating frequency of the is generally around several Hz.
文摘Electric fields induced by ring and pin electrodes in electrostatic charged powder sprayingtechnique are analysed. The fundamental formulae to deseribe these fields have been built up. Theseformulae could be used to design electrostatic charged podwer spraying system. The chargingeffectiveness of ring and pin electrode is experimentally investigated and compared each other. Theperformance of ring electrode is better than that of pin electrode.
文摘The aim of this paper is to study the behaviour of bipolar corona with a dual parallel corona bar and a metallic plate. The experimental results show that under otherwise identical conditions, the discharge depends strongly on the electrode separation between the bars. By investigating various separations, the corona regime can be divided into three regions: independent, shunted, and shorted. The criterion for eliminating electrostatic charge without over compensation is also given.
文摘In verifying antiretroviral efficacy of a Nigerian broad spectrum antiviral medicine (Antivirt<span style="white-space:nowrap;"><sup>®</sup></span>), the Nigerian Institute of Medical Research certified it safe by toxicological test on laboratory animals, before commencing treatment of three HIV/AIDS patients whose viral loads varied widely (millions, hundreds of thousands and thousands). To overcome errors associated with such wide differences in subject-classes, percentages of viral load-reductions were calculated instead of comparing their viral loads. After first month of the Antivirt<span style="white-space:nowrap;"><sup>®</sup></span>-treatment, means of ranked viral loads of the patients significantly (P ≤ 0.05) increased from 10.00 ± 7.21 to 11.30 ± 5.51 (-41.03% infection-reduction rate) instead of reducing. From second month of the trial, their viral loads started to reduce, continuously, so that their infection-reduction rates have been increasing from that -41.03%, to -38.22% in the second month;23.98% in the third month;31.76% in the fourth month and 64.12% after the fifth month.
文摘Two electrically charged rings of different sizes are assembled along their common vertical symmetry axis through their centers. The bottom ring is secured on a horizontal support while the top one is loose. For a set of practical values characterizing the charged rings we envision a scenario where the mutual electric repulsion between the rings and the weight of the top ring results in stable nonlinear oscillations. To quantify the characteristics of the oscillations, we utilize a Computer Algebra System specifically <em>Mathematica</em> [1]. We accompany the analysis with a simulation for a comprehensive visual understanding.
文摘<i>COVID</i>-19 <i>virus</i> has positive electrical charges. So, particles that are negatively charged would, by opposite charges-electrostatic attraction, inhibit its replication’s first stage (attachment to cells) and mop its extra-cellular particles. Positively charged particles would similarly mop/destroy cells it infects because unlike healthy cells which are neutral, infected/tumor cells have negative electrical charges. <i>Nanoparticles</i> (0.96 nm) of Aluminum-magnesium silicate (AMS), WHO-approved medicine/adjuvant have both negative and positive charged ends. As adjuvant it improves antimicrobials’ efficacies (clearing secondary infections) while as silicate it enhances immunity. By inhibiting viral replication;mopping extra-cellular viruses/abnormal cells;clearing secondary infections;enhancing immunity, AMS terminates viral-infections/abnormal cells’ metastases. Natural AMS has impurities and its deposits are not found in Nigeria. So, Aluminum silicate and Magnesium silicate (WHO-approved medicines) were used for <i>Medicinal synthetic AMS</i> {MSAMS: Al<sub>4</sub> (SiO<sub>4</sub>)<sub>3</sub> + 3Mg<sub>2</sub>SiO<sub>4</sub> → 2Al<sub>2</sub>Mg<sub>3</sub> (SiO<sub>4</sub>)<sub>3</sub>}. Since AMS is un-absorbable, dextrose monohydrate is incorporated in MSAMS-formulations to convey its <i>Nanoparticles</i> into blood for circulation to all organs/tissues (active-transportation). The MSAMS achieved quick cure (within 3 days) of all four COVID-19 patients used for its first-phase trial (one in Nigeria, two in Cameroon, one in Tanzania).
基金supported by the Fujian Province Natural Science Foundation under Grant No.2012J01235
文摘In solid processing systems, electrostatic problems are commonly observed for granules of various shapes. However, a complete understanding of the basic dependence of electrostatic charge generation on particle shape has yet to be established. This observation motivated the present study on examining the effect of granular shape on electrostatics. In this study, polyvinyl chloride (PVC) granules (diameter 1.1-4.1 ram, in the shape of a triangle or trapezium) were first discharged to remove any residual charges and sub- sequently their electrostatic charging characteristics were studied by allowing a granule to slide along a pipe wall. Several factors such as granular front-facing angle, length-ratio, sliding area, sliding orienta- tion, sliding times, and relative humidity were considered when studying their effects on the electrostatic charging of granules. It was found that triangular granules with smaller front-facing angles tended to generate more electrostatic charge. The amount of electrostatic charge increased with granular length- ratio and sliding area but decreased with humidity. In addition, granular sliding in the orientation of the front-facing angle (for triangular granules) or the short side (for trapezoidal granules) generated more electrostatic charge than that in the orientation of the long side. For both granule shapes, the elec- trostatic charge increased with granular sliding times and reached a saturated state after around 8-9 sliding movements. The saturated electrostatic charge increased with either granular length ratio or sliding area.
基金This work was supported by National Natural Science Foun- dation of China (Grant Nos. 51376153 and 51406235) Science Foundation of China University of Petroleum, Beijing (Grant No. 2462013YJRC030). We greatly acknowledge the suggestions given by Professor Chi-Hwa Wang (National University of Singapore) on the electrostatics characterization and equilibrium charge concept in this study.
文摘Electrostatic phenomena are commonly observed in the processing of solids. However. the working mech- anism of electrostatic charge generation for single granules and particularly, their electrostatic equilibria have not been properly understood. In this work, repeated-sliding charging experiments with single granules were investigated for their electrostatic generation particularly from the perspective of tribo- electrification equilibrium. Factors including granule length-ratio, sliding face shape, sliding times, sliding area, sliding velocity, front-facing edge, and sliding-plate inclined-angle were found to have an obvious effect on granule charge generation. Length-ratio and sliding area have significant effects as the gran- ules evolved toward an equilibrium state. Equilibrium charge is suggested as a variable expressing the charging propensity of the material. In addition, under the same working conditions, a semi-cylindrical granule generates greater charge than a rectangular granule.
基金supported by the National Natural Science Foundation of China (No. 51202292)
文摘To develop a depth filter based on the electrostatic adsorption principle, positively charged microporous ceramic membrane was prepared from a diatomaceous earth ceramic membrane.The internal surface of the highly porous ceramic membrane was coated with uniformly distributed electropositive nano-Y2O3 coating. The dye removal performance was evaluated through pressurized filtration tests using Titan Yellow aqueous solution. It showed that positively charged microporous ceramic membrane exhibited a flow rate of 421 L/(m^2·hr) under the trans-membrane pressure of 0.03 bar. Moreover it could effectively remove Titan Yellow with feed concentration of 10 mg/L between pH 3 to 8. The removal rate increased with the enhancement of the surface charge properties with a maximum rejection of 99.6%. This study provides a new and feasible method of removing organic dyes in wastewater. It is convinced that there will be a broad market for the application of charged ceramic membrane in the field of dye removal or recovery from industry wastewater.
基金supported by the National Natural Science Foundation of China(Nos.21374052 and 11174163)K.C.Wong Magna Fund in Ningbo University
文摘The adsorption of weak polybase on oppositely charged planar surfaces has been investigated numerically by using the self-consistent field theory(SCFT). Particular attention was paid to the interplay of monomer-surface electrostatic and non-electrostatic interactions in the adsorption behaviors of weak polybase. In this study, the strength of monomer-surface non-electrostatic interactions was set to be no more than the thermal energy kBT. It was found from the numerical study that in the regime of low surface charge density of the substrate and low p H or high bulk degree of ionization, both the screeningenhanced and screening-reduced salt effects emerge. On the contrary, in the opposite regime, only the screening-reduced salt effect was observed. Moreover, the overall charge neutrality inside the adsorption layer was analyzed. The underlying mechanism governing the adsorption behaviors of weak polybase on oppositely charged surfaces was elucidated.
基金supported by the National Natural Science Foundation of China(No.51278409)the Education Department of Shaanxi Province(No.15JS046)
文摘Na-rich birnessite(NRB) was synthesized by a simple synthesis method and used as a high-efficiency adsorbent for the removal of ammonium ion(NH+4) from aqueous solution.In order to demonstrate the adsorption performance of the synthesized material,the effects of contact time,pH,initial ammonium ion concentration,and temperature were investigated.Adsorption kinetics showed that the adsorption behavior followed the pseudo second-order kinetic model.The equilibrium adsorption data were fitted to Langmuir and Freundlich adsorption models and the model parameters were evaluated.The monolayer adsorption capacity of the adsorbent,as obtained from the Langmuir isotherm,was 22.61 mg NH+4-N/g at283 K.Thermodynamic analyses showed that the adsorption was spontaneous and that it was also a physisorption process.Our data revealed that the higher NH+4adsorption capacity could be primarily attributed to the water absorption process and electrostatic interaction.Particularly,the high surface hydroxyl-content of NRB enables strong interactions with ammonium ion.The results obtained in this study illustrate that the NRB is expected to be an effective and economically viable adsorbent for ammonium ion removal from aqueous system.
基金We thank the Natural Science Foundation of China (Grant No. 51376084) and the Postgraduate Scientific Research and Innovation Project of Jiangsu (Grant No. KYLX_1037) for support.
文摘The behavior of particles impacting the surface of a charged droplet involves adhesion, rebound, and submersion. In the present study, a numerical model for simulating particle impacts on charged droplets is presented that takes into account the various impact modes. With the droplet considered as a solid boundary, the criterion for rebounding is that the particle's impact angle is 〈85°. The simulated trajecto- ries of the particles are verified by comparing with experimental data for low-velocity particles to assess the reliability of the model. For impact angles 〉85°, particles undergo three distinct modes depending on normal impact velocities. The critical velocity of adhesion/rebound and rebound/submersion is used to identify the mode that the particles are undergoing. The criteria are also verified by comparing with ana- lytical data. The results show that the impact angle of particles increases with increasing Coulomb number and decreases dramatically with increasing Stokes number, both of which lead to a high probability for particle rebound.