Chapter
To read the full-text of this research, you can request a copy directly from the authors.

Abstract

Many accidents including large disasters are triggered by electrostatic discharge. Human lives and billions of dollars in property damage are lost every year, mainly due to the unobtrusive condition of electrostatic charge: it is not detected by human vision and other senses, as opposed for instance to mass and temperature. Accumulated charge in any portion of matter is hardly perceptible without suitable instrumentation. Electrified materials may appear harmless and safe to the naked eye, even when they are storing large amounts of charge, approaching the dielectric breakdown limits. For this reason, safety codes for the avoidance of hazards due to static electricity are very important and they are constantly updated in industrial environments. This chapter describes situations where electrostatic charge is a safety concern together with protective measures, discussing them with the help of recent knowledge on charging mechanisms and charge stability in various systems.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the authors.

... Electrostatic charging is an issue for electronics (packing and transport), fuel tanks and equipment in explosive environments [1,2]. Electrostatic discharge (EDS) during assembling, packing and shipping causes severe economic loss [3]. Antistatic and electrostatic dissipative materials with surface resistivity (<1 × 10 12 Ω/sq) resolve this issue. ...
... Poly(lactic) acid (PLA) 3D printing grade with trade name Ingeo BioPolymer 3D850 with a specific density of 1.24 g/cm 3 and melt flow rate (MFR) of 7-9 g/10 min (ASTM D1238) in pellet form was supplied by NatureWorks LLC, Plymouth, MN, USA. PBAT (item code: CPLNA-03459 BLN0430015; item description: Renol 03459 PBAT CMP Natural) natural to off-white granules with a density of 1.27 g/mL at 20 • C (ISO 1183-1) and a melt flow index (190/2.16 ...
... When the biochar content in the composites increases from 0 wt% to 10 wt%, surface resistivity decreases by two orders of magnitude. Compared to other carbon-based composites, the decrease in electrical resistivity is not so drastic; however, the composite with 10 wt% of biochar shows a surface resistivity of ∼10 11 Ω/sq, which is lower than the previously reported value (3 × 10 12 Ω/sq with 10 wt% of biochar) in the PLA/PBAT/biochar composites [3,56]. This low electrical resistivity is due to the high concentration of sp 2 hybridised carbon in coconut shell biochar. ...
Article
Full-text available
Biochar-based environment-friendly polymer composites are suitable substitutes for conventional non-biodegradable polymer composites. In this work, we developed polylactic acid (PLA)/polybutylene adipate-co-terephthalate (PBAT)/biochar (BC) composites with improved mechanical and electrical properties for antistatic applications. Coconut shell biochar was obtained through the pyrolysis of coconut shell in an inert atmosphere, and characterised using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD), to investigate the morphology and structural properties. The biochar was converted to powder form, sieved to reduce the particle size (≤ 30 μm diameters), and melt-mixed with PLA and PBAT to form composites. The composites were extruded to produce 3D printing filaments and, eventually, 3D-printed tensile specimens. The tensile strength and tensile modulus of the 3D-printed PLA/PBAT/BC (79/20/1) composite with 1 wt% of biochar improved by 45% and 18%, respectively, compared to those of PLA/PBAT (80/20). The interfacial interaction between the biochar and polymer matrix was strong, and the biochar particles improved the compatibility of the PLA and PBAT in the composites, improving the tensile strength. Additionally, the electrical resistivity of the composite did reduce with the addition of biochar, and PLA/PBAT/BC (70/20/10) showed the surface resistivity of ~1011 Ω/sq , making it a suitable material for antistatic applications.
... Therefore, the charge build-up at the device should be relatively small. Safety related to electrostatic charge buildup on the body self-capacitance is similar to ESD safety, a topic that has been extensively studied in literature [36].The proposed method is expected to apply to ambulatory animal or human body, however and as a proof of concept the study has been made on mouse cadavers because they are easy to work with to verify the concept. Also, the cadaver accurately models the electrical characteristics of a live animal, provided they have been stored and revived properly. ...
... Therefore, the charge build-up at the device should be relatively small. Safety related to electrostatic charge buildup on the body self-capacitance is similar to ESD safety, a topic that has been extensively studied in literature [36].The proposed method is expected to apply to ambulatory animal or human body, however and as a proof of concept the study has been made on mouse cadavers because they are easy to work with to verify the concept. Also, the cadaver accurately models the electrical characteristics of a live animal, provided they have been stored and revived properly. ...
Article
O crescimento da população e as aspirações por melhores condições de vida material demandam aumento na disponibilidade de energia para as atividades humanas, sob diferentes circunstâncias e contingências, nas cidades, em regiões de baixa densidade de população e em locais remotos. Portanto, o fornecimento de energia tem aspectos diversificados, que exigem soluções diferenciadas. O cenário global da produção e distribuição de energia está mudando rapidamente. A introdução e desenvolvimento de novas formas de produção de energia atende a vários Objetivos de Desenvolvimento Sustentável (ODSs) da Organização das Nações Unidas (ONU) e motiva um grande esforço de investimento público e privado, de pesquisa e desenvolvimento em Ciência e Tecnologia. Entretanto, esse processo é modificado por muitos fatores: a manipulação dos preços do petróleo, as questões ambientais, culturais e sociais, as mudanças climáticas, fatores geográficos, a eletrificação dos transportes, guerras, pandemia e decisões políticas em todos os níveis. A produção de energia solar e eólica cresce rapidamente em muitos países, enquanto a biomassa, usada há milênios, está sendo explorada de novas formas, com excelentes resultados. Existe ainda uma grande atividade de pesquisa e desenvolvimento (P& D) em torno de fenômenos que poderão embasar novas formas de produção de energia. Esse processo exige a tomada de decisões e a ação de governos, empresas e cidadãos, com efeitos de pequeno, médio e longo prazos. No passado, decisões bem instruídas e voltadas para o bem comum produziram resultados positivos, enquanto as decisões pouco iluminadas tiveram resultados pobres e causaram prejuízos, sociais e econômicos.
Article
Polymer materials have been widely used in modern industries duo to their characteristics such as lightweight, low price, and corrosion resistance. However, the inherent insulation of polymer materials can cause static electricity, which has become one of the major problems that has limited their application. Meanwhile, as the basis for ensuring the service field and life of the polymer materials, mechanical properties can affect the comprehensive properties of the polymer materials. Therefore, research on the preparation of composite materials with both antistatic properties and good mechanical properties with antistatic‐reinforced modification has attracted extensive attention and achieved important progress. Based on the principle of electrostatic electrification of antistatic‐reinforced modification, antistatic mechanisms and main preparation strategies, this paper summarized the research achievements of the antistatic‐reinforced polymer materials in recent years. Additionally, some factors that have affected their antistatic properties were presented, and the development trends of the antistatic‐reinforced polymer materials based on the deficiencies of current research were proposed.
Article
Electrostatic discharge is a fatal threat to a variety of electronic products. Here we report on a polymer nanocomposite composed of a dielectric polymer embedded with aligned core-shell structured nanowires for highly efficient distributed electrostatic discharge protection. The dielectric nanocomposite is capable of self-adaptive charge release, stemming from the nonlinear interface built in the Bi/Co oxide coated ZnO nanowires that leads to a "hand-in-hand" double-Schottky barrier. The ultralow filler concentration (e.g., 0.5 vol %) endows the nanocomposite with low permittivity (close to the pristine polymer matrix) and high optical transmittance (75%) in the visible light wavelength range, which is desirable in packaging materials and display coatings for portable electronics. The effectiveness for electrostatic discharge protection was validated with an organic light-emitting diode screen protected by the nanocomposite that survived multiple rounds of electrostatic discharge.
Article
Full-text available
Nanostructured materials have gained importance in recent years due to their significantly enhanced properties. In particular, electrochemistry has a special role in producing a variety of nanostructured materials. In the current review, we discuss the superiority of electrochemical deposition techniques in synthesizing various nanomaterials that exhibit improved characteristics compared with materials produced by conventional techniques, as well as their classification, synthesis routes, properties and applications. The superior properties of a nanostructured nickel coating produced by electrochemical deposition are outlined. The properties of various nanostructured coating materials produced by electrochemical techniques are also described. Finally, the importance of nanostructured coatings in industrial applications as well as their potential in future technologies is emphasized.
Article
Full-text available
This work introduces a new concept to integrate energy-harvesting devices with the aim of improving their throughput, mainly in terms of scavenged energy density and frequency tunability. This concept, named energy harvester in package (EHiP), is focused on the heterogeneous integration of a MEMS die, dedicated to scavenging energy, with an auxiliary chip, which can include the control and power management circuitry, sensors and RF transmission capabilities. The main advantages are that the whole die can be used as an inertial mass and the chip area usage is optimized. Based on this concept, in this paper we describe the development and characterization of a MEMS die fully dedicated to harvesting mechanical energy from ambient vibrations through an electrostatic transduction. A test PCB has been fabricated to perform the assembly that allows measurement of the resonance motion of the whole system at 289 Hz. An estimated maximum generated power of around 11 μW has been obtained for an input vibration acceleration of ∼10 m s⁻² when the energy harvester operates in a constant-charge cycle for the best-case scenario. Therefore, a maximum scavenged power density of 0.85 mW cm⁻³ is theoretically expected for the assembled system. These results demonstrate that the generated power density of any vibration-based energy harvester can be significantly increased by applying the EHiP concept, which could become an industrial standard for manufacturing this kind of system, independently of the transduction type, fabrication technology or application.
Article
Full-text available
The self-assembly of amphiphilic building blocks has attracted extensive interest in myriad fields in recent years, due to their great potential in the nanoscale design of functional hybrid materials. Microfluidic techniques provide an intriguing method to control kinetic aspects of the self-assembly of molecular amphiphiles by the facile adjustment of the hydrodynamics of the fluids. Up to now, there have been several reports about one-step direct self-assembly of different building blocks with versatile and multi-shape products without templates, which demonstrated the advantages of microfluidics. These assemblies with different morphologies have great applications in various areas such as cancer therapy, micromotor fabrication, and controlled drug delivery.
Article
Full-text available
Airborne particles are known to cause illness and to influence meteorological phenomena. It is therefore important to monitor their concentrations and to identify them. A challenge is to collect micro and nanoparticles, microorganisms as well as toxic molecules with a device as simple and small as possible to be used easily and everywhere. Electrostatic precipitation is an efficient method to collect all kinds of airborne particles. Furthermore, this method can be miniaturized. A portable, silent, and autonomous air sampler based on this technology is therefore being developed with the final objective to collect very efficiently airborne pathogens such as supermicron bacteria but also submicron viruses. Particles are collected on a dry surface so they may be concentrated afterwards in a small amount of liquid medium to be analyzed. It is shown that nearly 98 % of airborne particles from 10 nm to 3 μm are collected.
Article
Full-text available
Motivated by specific applications, electrostatically actuated bistable arch shaped micro-nano resonators have attracted growing attention in the research community in recent years. Nevertheless, some issues relating to their nonlinear dynamics, including the possibility of chaos, are still not well known. In this paper, we investigate the chaotic vibrations of a bistable resonator comprised of a double clamped initially curved microbeam under combined harmonic AC and static DC distributed electrostatic actuation. A reduced order equation obtained by the application of the Galerkin method to the nonlinear partial differential equation of motion, given in the framework of Euler–Bernoulli beam theory, is used for the investigation in this paper. We numerically integrate the obtained equation to study the chaotic vibrations of the proposed system. Moreover, we investigate the effects of various parameters including the arch curvature, the actuation parameters and the quality factor of the resonator, which are effective in the formation of both static and dynamic behaviors of the system. Using appropriate numerical tools, including Poincaré maps, bifurcation diagrams, Fourier spectrum and Lyapunov exponents we scrutinize the effects of various parameters on the formation of chaotic regions in the parametric space of the resonator. Results of this work provide better insight into the problem of nonlinear dynamics of the investigated family of bistable micro/nano resonators, and facilitate the design of arch resonators for applications such as filters.
Article
Full-text available
Supramolecular self-assembly offers routes to challenging architectures on the molecular and macroscopic scale. Coupled with microfluidics it has been used to make microcapsules—where a 2D sheet is shaped in 3D, encapsulating the volume within. In this paper, a versatile methodology to direct the accumulation of capsule-forming components to the droplet interface using electrostatic interactions is described. In this approach, charged copolymers are selectively partitioned to the microdroplet interface by a complementary charged surfactant for subsequent supramolecular cross-linking via cucurbit[8]uril. This dynamic assembly process is employed to selectively form both hollow, ultrathin microcapsules and solid microparticles from a single solution. The ability to dictate the distribution of a mixture of charged copolymers within the microdroplet, as demonstrated by the single-step fabrication of distinct core–shell microcapsules, gives access to a new generation of innovative self-assembled constructs.
Article
Full-text available
This paper describes a novel thread-shaped power generator which can be incorporated into cloth. A carbon-activated cotton thread is utilized for harvesting electrostatic energy from environment using contact and friction electrifications. A core of cotton thread was treated with carbon black nano particles to provide conductivity, and then encapsulated with a thin layer of polydimethylsiloxane for stability and protection. Electrostatic charges have been collected from carbon-activated threads stitched on pieces of textiles by repeated rubbing and tapping with a ploytetrafluoethylene sheet. An average open-circuit voltage of approximately -60.9 V has been generated from the thread-shaped generator with rubbing mode.
Article
Full-text available
Considering the relationship between concentration and vapor pressure (or the relationship between concentration and fugacity) single-ion activity coefficients are definable in purely thermodynamic terms. The measurement process involves measuring a contact potential between a solution and an external electrode. Contact potentials are measurable by using thermodynamically reversible processes. Extrapolation of an equation to zero concentration and ionic strength enables determination of single-ion activity coefficients. Single-ion activities can be defined and measured without using any extra-thermodynamic assumptions, concepts, or measurements. This method could serve as a gold standard for the validation of extra-thermodynamic methods for determining single-ion activities. Furthermore, it places the concept of pH on a thermodynamically solid foundation. Contact potential measurements can also be used to determine the Gibbs free energy for the transfer of ions between dissimilar materials. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Book
Many industrial, power generation and chemical processes produce unwanted fine particulate material as a consequence of their operation. Electrostatic precipitation is a highly efficient method of removing entrained particulate contaminants from exhaust gases and is extensively used in these industries to limit particulate emissions. New legislation aimed at improving the environment by further limiting these discharges has resulted in the technique undergoing considerable development over the past decade, to the point where it has become the method of choice, over a wide range of applications, for limiting particulate discharges. In this new book, the editor has brought together an international team of contributors, mainly industrialists and consultants, to produce an authorative and practical guide to electrostatic precipitation. This book is of interest to all those in process industries or power generation and to academics concerned with gas cleaning and environmental issues.
Book
The book starts with an exposition of the relevant properties of ions and continues with a description of their solvation in the gas phase. The book contains a large amount of factual information in the form of extensive tables of critically examined data and illustrations of the points made throughout. It covers: the relevant properties of prospective liquid solvents for the ions the process of the transfer of ions from the gas phase into a liquid where they are solvated various aspects of the solutions of the ions, such as structural and transport ones and the effects of the ions on the solvent dynamics and structure what happens in cases where the solvent is a mixture selective solvation takes place applications of the concepts expounded previously in fields such as electrochemistry, hydrometallurgy, separation chemistry, biophysics, and synthetic methods.
Article
An electrostatic discharge between postdoctoral researcher Thea Ekins-Coward and a gas storage tank containing hydrogen, oxygen, and carbon dioxide likely caused an explosion at the University of Hawaii, Mānoa, in which Ekins-Coward lost one of her arms, according to a report by the University of California Center for Laboratory Safety (UCCLS). UH hired UCCLS to conduct an independent investigation of the March 16 accident and released the report on July 1. Another investigation by the Honolulu Fire Department, released in April, concluded that the cause was a spark from the pressure gauge. UCCLS dug deeper than the fire department and contracted with an outside laboratory to recreate and test the experimental setup. Those tests ruled out all causes other than a static discharge. Going beyond the immediate cause of the explosion, however, “the overall underlying cause of the accident was failure to recognize and control the hazards of an explosive
Article
We present the implementation of a three-dimensional mapping routine for probing solid-liquid interfaces using frequency modulation atomic force microscopy. Our implementation enables fast and flexible data acquisition of up to 20 channels simultaneously. The acquired data can be directly synchronized with commercial atomic force microscope controllers, making our routine easily extendable for related techniques that require additional data channels, e.g., Kelvin probe force microscopy. Moreover, the closest approach of the tip to the sample is limited by a user-defined threshold, providing the possibility to prevent potential damage to the tip. The performance of our setup is demonstrated by visualizing the hydration structure above the calcite (10.4) surface in water.
Article
Most pharmaceutical powders are dielectric materials that often accumulate charge during manufacturing process. In this study, triboelectrification of binary mixtures of drug and excipient has been investigated. Powder samples for charge measurement were mixed using a V-blender and dispensed directly into a Faraday cup. The mixtures at intermediate concentration exhibited significant charge mitigation. These unanticipated trends previously reported have been explored using process modeling approaches. Additionally, in silico computations have been performed to estimate the work function of the all contact materials. DEM simulations suggest that the drug particles (Ibuprofen) charge positively whereas the excipient (MCC) charges negatively when particle-particle collisions become substantial. This charge transfer is suspected to actually enhance electrostatic interaction between the drug and excipient and decrease the overall charge transfer between particle and wall.
Article
A triboelectric nanogenerator (TENG) is a simple and cost effective device that converts ambient mechanical energy into electricity based on the surface contact electrification of thin films. The limited surface charge density may affect the overall performance of the TENG. In this paper, a novel electret film based TENG (E-TENG) fabricated by corona charging is proposed that greatly enhances the effective surface charge density of the thin films as compared to those subjected to contact electrification. The short-circuit current, transferred electric charge density, and open-circuit voltage of the E-TENG have been investigated, using different corona charging voltages, pinpoint distances and times in order to explore the optimum experimental conditions. The short-circuit current, transferred electric charge density, and open-circuit voltage of the E-TENG are found to be about seven times larger than those of the ordinary polytetrafluoroethylene (PTFE) film based TENG. Based on corona charging, several multilayered E-TENGs have been fabricated, and the short-circuit current, transferred electric charge density, and open-circuit voltage of the E-TENGs with different number of layers are studied for achieving optimal performances. This work offers an effective approach for improving the effective surface charge density and thereby increasing the output capability of the TENG, which would greatly promote TENG applications in self-powered portable electronics and sensor networks.
Article
Here, an integrated microfluidic electrostatic sampler (IMES) was designed and evaluated, consisting of a unipolar charging chamber, a half cylinder precipitation electrode and a collection chip for automated air sample delivery. The collection chip includes a half-open microchannel covered with a hydrophobic mesh and a peristaltic micropump. Airborne particles were first charged in the charging chamber and then precipitated into the half-open microchannel by the electrostatic field. After sampling, the integrated micropump automatically delivered the collection liquid through the half-open microchannel to the liquid outlet, washing away those deposited particles into collection reservoir. The maximum allowable velocity in the half-open microchannel was higher than 200 mm/s which is well above the normal operating speed of sample delivery, thus water transportation was quite stable in use. The collection efficiencies of airborne particles and bio-particles were investigated for the sampler. The tested maximum sampling flow rate was 13.2 L/min and the corresponding maximum effective collection efficiency was about 40% for particles smaller than 5 μm at charging voltage of -1.8 kV and collecting voltage of -7 kV. The preliminary experiments showed that the collection efficiencies of bio-particles were about 16% with aerosolized Bacillus subtilis. The lower collection efficiency of bio-particles was partially due to the particle loss on the hydrophobic mesh. Taking into consideration its compact size and integrated function of charging and automatic liquid sample delivery, the IMES is a bioaerosol sampling system ready for integration with subsequent automated detection equipment.
Article
An electrostatic precipitator (ESP) based personal sampler with a laboratory based electrowetting-on-dielectric (EWOD) concentrator could provide a high concentration rate personal aerosol sampler system. A prototype system has been developed based on the concept of a lightweight personal ESP collecting aerosol particles onto a hydrophobic surface followed by the use of an EWOD actuated droplet system to transfer the deposited sample into a microlitre size water droplet. A personal sampler system could provide military or civilian personnel with a wide area biological monitoring capability supplying information on who has been infected, what they have been infected with, how much material they were exposed to and possibly where and when they were infected. Current commercial-off-the-shelf (COTS) personal sampler solutions can be bulky and use volumes of water to extract the sample that are typically a thousand times greater than the proposed method. Testing of the prototype ESP at a sample flow rate of 5Lmin−1 demonstrated collection efficiencies greater than 80% for sodium fluorescein particles larger than 4μm diameter and of approximately 50% at 1.5μm. The ESP-EWOD system collection efficiency measured for Bacillus atrophaeus (BG) spores with an air sample flow rate of 20Lmin−1 was 2.7% with a concentration rate of 1.9×105min−1. This was lower than expected due to the corona ions from the ESP affecting the hydrophobicity of the collection surface and hence the EWOD efficiency. However, even with this low efficiency the concentration rate is more than an order of magnitude higher than the theoretical maximum of the best current COTS personal sampler. For an optimised system, ESP-EWOD system efficiency should be higher than 32% with a comparable increase in concentration rate.
Article
Flexible nanogenerators that efficiently convert mechanical energy into electrical energy have been extensively studied because of their great potential for driving low-power personal electronics and self-powered sensors. Integration of flexibility and stretchability to nanogenerator has important research significance that enables applications in flexible/stretchable electronics, organic optoelectronics, and wearable electronics. Progress in nanogenerators for mechanical energy harvesting is reviewed, mainly including two key technologies: flexible piezoelectric nanogenerators (PENGs) and flexible triboelectric nanogenerators (TENGs). By means of material classification, various approaches of PENGs based on ZnO nanowires, lead zirconate titanate (PZT), poly(vinylidene fluoride) (PVDF), 2D materials, and composite materials are introduced. For flexible TENG, its structural designs and factors determining its output performance are discussed, as well as its integration, fabrication and applications. The latest representative achievements regarding the hybrid nanogenerator are also summarized. Finally, some perspectives and challenges in this field are discussed.
Article
Wireless sensor nodes deployed at remote and inaccessible locations need long lifetime power sources to prevent cost prohibitive periodic replacement. In this work, we present a radioisotope 63Ni energy converter using radioisotopepowered electrostatic vibration-to-electricity conversion. Free damped vibration happening in a suspended parallel plate structure with a mass enables a variable capacitance, which can be used to realize the generation of electricity energy by an external circuit. The MATLAB/Simulink is used to simulate the vibration and output power, and the Ansys is used to optimize the structure design. The results show that the optimized design structure with a first-order natural frequency of 500 Hz, a plate gap of 75 μm, and an external resistance of 90 kΩ can generate an average output power of 0.416 μW and conversion efficiency of 8.25%.
Article
This work is focused on analysing effect of accumulated dust particles' charge on PV module performance. In the Dundee University's laboratory, dust particles have been created through epoxy powder and charged by using corona and tribo-electric charging methods by varying the charge levels of the accumulated dust particles. The PV module output has analysed for finding a relation between charge levels of the accumulated dust particles and its output voltage. Obtained experimental results have shown that charge level of accumulated dust particles on PV module's have significant impact on its output and dust particle accumulations are not associated with panel tilt angle.
Article
This thoroughly updated edition continues to provide a concise overall coverage of colloid and surface chemistry, intermediate between the brief accounts in physical chemistry textbooks and the comprehensive coverage in specialized treatises. New information is included on the composition and structure of solid surfaces, dynamic light scattering, micro emulsions and colloid stability control. The book provides a sound, but easy to follow theoretical framework. It outlines relevant research techniques and considers technological applications. A basic knowledge of the principles of physical chemistry is assumed. It will appeal to a wide readership, both undergraduate and postgraduate students at universities and colleges of technology as well as scientists in industry who need a broad background in the subject.
Article
The high current ion source with the low energy beam transport (LEBT) will serve as injector into the proton LINAC to provide primary proton beam for the production of antiprotons. The pulsed ion source developed and built in CEA/Saclay operates with a frequency of 2.45 GHz based on ECR plasma production with two coils with 87.5 mT magnetic field necessary for the electron cyclotron resonance. The compact LEBT consists of two solenoids with a maximum magnetic field of 500 mT including two integrated magnetic steerers to adjust the horizontal and vertical beam positions. The total length of the compact LEBT is 2.3 m and was made as short as possible to reduced emittance growth along the beam line. To measure ion beam intensity behind the pentode extraction system, between solenoids and at the end of the beam line, two current transformers and a Faraday cup are installed. To get information about the beam quality and position, the diagnostic chamber with different equipment will be installed between the two solenoids. This article reports the current status of the proton injector for the facility of antiproton and ion research.
Article
A highly versatile soft gripper that can handle an unprecedented range of object types is developed based on a new design of dielectric elastomer actuators employing an interdigitated electrode geometry simultaneously maximizing both electroadhesion and electrostatic actuation, while incorporating self-sensing. The multifunctionality of the actuator leads to a highly integrated, lightweight, fast, soft gripper with simplified structure and control.
Article
Self-assembly is the autonomous organization of components into patterns or structures without human intervention. Self-assembling processes are common throughout nature and technology. They involve components from the molecular (crystals) to the planetary (weather systems) scale and many different kinds of interactions. The concept of self-assembly is used increasingly in many disciplines, with a different flavor and emphasis in each.
Article
Fundamental study and industrial application of ion exchange membranes started over half a century ago. Through ongoing research and development, ion exchange membrane technology is now applied to many fields and contributes to the improvement of our standard of living. Ion Exchange Membranes, 2nd edition states the ion exchange membrane technology from the standpoint of fundamentals and applications. It discusses not only various phenomena exhibited by membranes but also their applications in many fields with economical evaluations. This second edition is updated and revised, featuring ten expanded chapters. New to this edition is a computer simulation program of ion-exchange membrane electrodialysis for water desalination that provides a guideline for designing, manufacturing and operating a practical-scale electrodialyzer. Meant to replace experiments, this program will be an important asset to those with time and monetary budgets. New edition features ten revised and expanded chapters, providing the latest developments in ion exchange membrane technology Computer simulation program, accessible through a companion website, provides a guideline for designing, manufacturing and operating practical-scale electrodialyzers Attractive visual presentation, including many figures and diagrams.
Article
Atomic crystal structure affects the electromagnetic and thermal properties of common matter. Similarly, the nanoscale structure controls the properties of higher length-scale metamaterials, for example nanoparticle superlattices and photonic crystals. Electrostatic self-assembly of oppositely charged nanoparticles has recently become a convenient way to produce crystalline nanostructures. However, understanding and controlling the assembly of soft non-metallic particle crystals with long-range translational order remains a major challenge. Here, we show the electrostatic self-assembly of binary soft particle co-crystals, consisting of apoferritin protein cages and poly(amidoamine) dendrimers (PAMAM), with very large crystal domain sizes. A systematic series of PAMAM dendrimers with generations from two to seven were used to produce the crystals, which showed a dendrimer generation dependency on the crystal structure and lattice constant. The systematic approach presented here offers a transition from trial-and-error experiments to fundamental understanding and control over the nanostructure. The structure and stability of soft particle co-crystals is of major relevance for applications where a high degree of structural control is required, for example protein-based mesoporous materials, nanoscale multicompartments and metamaterials.
Article
This paper considers the risk of ignition of a flammable atmosphere within a chemical cargo tank by an electrical discharge from a water slug originating from a washing machine. Simple safety criteria are identified on the basis of new and existing measurements of space potential, assessed via an existing computational model which has been revised to account for other generally present charged objects. These criteria specify limitations for tank size, nozzle throughput and nozzle number for application regardless of residue type. The limitations roughly coincide with the largest tank sizes and water throughputs characteristic of chemical tankers and their washing operations. They are consistent with the good safety record of such operations as currently performed. However, the findings indicate that the situation has been reached where the proponents of changes in current practice need to demonstrate clearly the inherent safety of such changes.
Article
The electronic paper has been successfully applied on electronic readers (E-Readers). Among all electronic paper technologies, the electrophoretic display (EPD) would be the most popular one due to its promising visual quality for showing text only contents or gray-tone images. However, playing videos/animations on the EPD is still a big challenge, thus none of the commercial E-Readers can support such a fancy feature. This drawback limits the application scenarios of the E-Readers. In this paper, we propose an integrated driving system for playing videos on the EPD. The system contains a new real-time signal processing hardware engine for video halftoning. In addition, the entire system is driven with a new driving waveform aiming at the reduction of residue images and visual flickers.
Article
This paper considers more than 2000 dust explosion accidents that occurred worldwide between 1785 and 2012. The statistical features of these cases are first examined spatially and temporally. Accident frequencies at different levels of economic development are further discussed. China and the United States are chosen as examples to represent the differences in distribution features of dust explosions in countries with different economic development levels. Data for combustible dusts leading to dust explosions in both China and the United States are also collected and categorized. The features of ignition sources for dust explosions, the types of enterprises with high risk, and the critical equipment in such enterprises are also analyzed. The results could help identify hazards of dust explosions in various industries, monitor the critical equipment, and further suggest safety improvement procedures to reduce the probability and damage of dust explosions.
Chapter
Publisher Summary This chapter discusses polymer electrets for electronics, sensors, and photonics. Charging and poling can be viewed as an additional degree of freedom in the design of polymer electret devices. As a result, flexibility is achieved with which other materials—such as inorganic crystals or semiconductors—can hardly compete. The survey on measurement techniques presented in the chapter concentrates on new experimental analysis schemes—based on piezo-, pyro-, as well as linear and nonlinear optical effects—that complement traditional techniques from electret research. Charge electrets carry a quasipermanent excess charge trapped at their surface or in their bulk. Bulk trapping is possible in amorphous phases and crystalline phases and in semicrystalline polymers at interfaces between the amorphous and crystalline regions. Charge electrets are based on good insulating polymers with small dielectric losses. Dipole electrets show a preferential orientation of molecular dipoles—that is, frozen, quasipermanent dipole orientation polarization in amorphous phases and permanent dipole orientation polarization in crystalline phases.
Article
Using the electrostatic charges created on the surfaces of two dissimilar materials when they are brought into physical contact, the contact induced triboelectric charges can generated a potential drop when the two surfaces are separated by a mechanical force, which can drive electrons to flow between the two electrodes built on the top and bottom surfaces of the two materials. This is the triboelectric nanogenerator (TENG). Ever since the first report of the TENG in January 2012 by Wang et al., its output area power density reaches 500 W/m2, an instantaneous conversion efficiency of ~70% and total energy conversion efficiency of up to 85% have been demonstrated. This article provides a comprehensive review about the four modes of the TENGs, their theoretical modelling, and the applications of TENGs for harvesting energy from human motion, walking, vibration, mechanical triggering, rotating tire, wind, flowing water and more. A TENG can also be used as a self-powered sensor for actively detecting the static and dynamic processes arising from mechanical agitation using the voltage and current output signals of the TENG, respectively, with potential applications as mechanical sensors and for touch pad and smart skin technologies. The potential of TENG for harvesting ocean wave energy is also discussed as a potential approach for the blue energy by harvesting ocean wave energy at an estimated power density of 1.15 MW/km2.
Article
The rheological behaviour of anatase dispersions was compared with the ζ potential, when the pH (from 3 to 10) and sodium chloride concentration (from 0 to 1 mol dm−3) was varied over a wide range. The isoelectric point, pHiep, is shifted to higher values with increasing salt concentration until a charge reversal was no longer observed at a concentration of 1 mol dm−3 NaCl. The rheological properties were analyzed in the form of the critical yield stress and the shear stress and viscosity at arbitrarily selected high and low shear rates, respectively. The maximum of the rheological properties was found to correlate with to the pHiep. The electrokinetic and rheological features of the system were related to a recent theory of Hunter et al. [J. Colloid Int. Sci. 28 (1968) 250] by plotting the yield stress against the square of the ζ potential for each salt concentration. The acidic branch, i.e. when pH<pHiep, of these curves followed the expectations of the theory quite well. For the alkaline branch (pH>pHiep), however, the curves did not show the expected linear behaviour. Also when comparing the influence of pH and sodium chloride concentration on the rheology, it was found that on the acidic yield stress branch the dependency of pH and salt concentration was very different from the one on the alkaline branch. On the acidic branch, low ionic strengths shared a common straight line. On the contrary, the alkaline branch had separate linear dependencies for each salt concentration. Moreover, the lines on the alkaline side seemed to be quite parallel for medium salt concentrations.
Chapter
In this chapter the main principles of main-group chemical bonding and of important trends in the Periodic Table are reviewed, with the results of modern quantum-chemical studies in mind. A particular focus is on the radial nodes of atomic orbitals (AOs) and on their consequences for orbital sizes and related chemical properties. The differences between 2p-elements and their heavier homologues are discussed on the basis of Kutzelnigg's seminal exposition on hybridization defects. Many observations may be explained readily within this framework, including the inert-pair effect, stereochemically active or inactive lone pairs, nonintuitive relations between bond lengths and binding energies, the stability of N-heterocyclic carbenes and of related compounds, preferences for multiple bonding, magnetic resonance parameters, and so on. Even the preference for “hypervalency” of the heavier p-block elements can be related to size and energy of the p-type valence orbitals of the central atom rather than to extensive d-orbital participation in bonding. Incomplete screening of nuclear charge by core shells and relativistic effects as important aspects of secondary periodicity are also discussed. Finally, the role of the heavier group 2 atoms as “honorary d-elements” is scrutinized in the context of unusual structural observations.
Article
Electrostatic potential decay on corona-charged low-density polyethylene (LDPE) was recorded as a function of position and time, using a macroscopic scanning electrode and also Kelvin force microscopy. Potential decays independently in adjacent sample areas until reaching equilibrium at negative values (4.6 ± 0.7 V), irrespective of the initial potential signal. Other observations already described in literature were confirmed: negative potential decays slower than positive potential and the relative humidity has a large effect on the dissipation rates. These results are discussed considering ion exchange associated to adsorption and desorption of water clusters at the solid–gas interface.