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Graphene has emerged as an ultrafast photonic material for on-chip all-optical switching applications. However, its atomic thickness limits its interaction with guided optical modes, resulting in a high switching energy per bit. Herein, we propose a novel technique to electrically control the switching energy of an all-optical graphene switch on a silicon nitride waveguide. Using this technique, we theoretically demonstrate a 120 µm long all-optical graphene switch with an 8.9 dB extinction ratio, 2.4 dB insertion loss, a switching time of ∼ 16 × . This technique paves the way for the emergence of ultra-efficient all-optical graphene switches that will meet the energy demands of next-generation photonic computing systems, and it is a promising alternative to lossy plasmon-enhanced devices.

We propose an F-band phase shifter based on the nematic liquid crystals (NLCs). The proposed phase shifter is formed by a voltage-controlled cavity through introducing an NLC layer between a dipole structure array and a metal floor. Under the action of electric field, the orientation of the NLC molecules will be deflected. We adjust the resonant frequency and phase of the reflected electromagnetic (EM) wave by tuning the permittivity. The transmission characteristics and the LC parameters are calculated and analyzed for EM waves within the frequency range from 85 to 115 GHz. The LC-based device with a $30\times 30$ array of two parallel unequal dipoles is printed on a quartz substrate, with 4 cm $\times {4}$ cm area and $490~\mu \text{m}$ thickness. The experimental results show that phase shift of zero to 350.7° is achieved at 104.2 GHz by changing the applied bias voltage on the LC layer from 0 to 20 V. Considering the anisotropy and inhomogeneity of the LC, an improved electrification model is established and compared with the test results. The proposed phase shifter is expected to find several applications in millimeter wave and terahertz reconfigurable antenna systems.

We explore the tunability of the phonon polarization in suspended uniaxially strained graphene by magneto-phonon resonances. The uniaxial strain lifts the degeneracy of the LO and TO phonons, yielding two cross-linearly polarized phonon modes and a splitting of the Raman G peak. We utilize the strong electron-phonon coupling in graphene and the off-resonant coupling to a magneto-phonon resonance to induce a gate-tunable circular phonon dichroism. This, together with the strain-induced splitting of the G peak, allows us to controllably tune the two linearly polarized G mode phonons into circular phonon modes. We are able to achieve a circular phonon polarization of up to 40 % purely by electrostatic fields and can reverse its sign by tuning from electron to hole doping. This provides unprecedented electrostatic control over the angular momentum of phonons, which paves the way toward phononic applications., 11 pages, 7 figures

This work presents the first fully packaged silicon photonics 8×8 switch with monolithically integrated electrical control circuits in 90nm SOI CMOS. The switch is a strictly non-blocking network built from 2×1 and 2×2 Mach-Zehnder switches (MZSs). 180 DACs tune the MZSs and 112 ADCs measure optical power across the network for feedback control. Digital interfaces provide low-speed tuning/monitoring and high-speed switching controls. 5.6ns optical switching is achieved with thermo-optically tuned crosstalk

This paper presents the results of an investigation of Passivated Emitter Rear Cell (PERC) solar cell technology and the current understanding of the fundamental device physics. The research work has been focused on the influence of the bulk lifetime, the incident angle of the solar radiation, and temperature dependence on electrical properties of the considered PERC solar cell by using TCAD-ATLAS Silvaco. Also, this paper shows the best results obtained recently and some guidelines to improve still more the efficiency of the devices. The optimization at 300 K led to the following results Jsc = 41.70 mA/cm2, Voc = 0.727 V, FF = 80.53 %, P $_{{\max }} =$ 244.439 W/m− 2, and η = 24.44 % which are close with those found in different research works. This technology provides a better electrical control over the cell and thus leads to valuable improvements in device performance.

Quality control is increasingly important in printed circuit board manufacturing to be sure that electronic equipment is reliable.Under the circumstances, optical and electrical methods were here applied to test printed circuit boards.During electrical control, a flying probe test revealed such typical discontinuities in the electrical circuits of printed circuit boards as open circuit defects and short. According to the tests, the discontinuities were caused by such defects as etching, foreign inclusions and the reduction of the distance between conductors, as well. Both optical and electrical approaches to control the quality of printed circuit boards are able to make the system of quality control much more efficient.

Different production technology and process have different requirements for control circuit. However, no matter what kind of control circuit, it is composed of some basic control links. Programmable controller is a common electronic data control program, which not only plays a lot of advantages in industrial control system, but also is more and more widely used in people's daily life. It is an essential basic equipment in industrial automation system at present. As a kind of high-precision three-coordinate measuring equipment, laser dynamic tracker can be used to measure the spatial position of various single parts and complete sets of equipment. This paper mainly introduces the application of laser tracking system in electrical control and programmable controller, and looks forward to the development prospect of laser tracking detection technology.

In this paper, a switchable broadband polarizer based on the electric field directed reconfigurable assembly of gold nanowires (NWs) is presented. Taking advantage of the collective optical properties of the two-dimensional gold NW lattices, we have experimentally demonstrated that transmission of linear polarized light can be purposely controlled using a dual electrode design to reversibly rotate the lattice by 90° on-demand. In addition, our experiments reveal that the transmission control is closely related to the geometrical dimensions of the NWs as well as the applied electric field conditions.

An apparatus is described which permits the automatic determination of the oxygen consumption of three fish and a control for 24 hours per day. This is made possible by an electrical control system operating four three-way valves which allow water from one of four respiration chambers at a time to flow past an oxygen electrode for quarter-hour periods. These values are registered successively on a recorder.

Modulation of visible light has been easily achieved for decades, but modulation of terahertz (THz) light still remains a challenge. To address this issue, the Fresnel equations have been developed to describe a conductive interface in a total internal reflection geometry and reveal a new approach for modulation. To demonstrate this new mechanism, a broadband device achieving a modulation depth greater than 90% between 0.15 and 0.4 THz, and reaching a maximum of 99.3% at 0.24 THz has been designed. The modulation is achieved by applying a gate voltage between −0.1 and 2 V to a graphene layer in a total internal reflection geometry. Compared to conventional designs, the high modulation is realized without assistance from metamaterial structures, resonant cavities, or multistacked graphene layers. Thus, the design is efficient and easy-to-fabricate and can be easily retrofitted to most existing THz systems. This work opens up a new avenue of research as the device has verified the theory and demonstrates how it can be used to make practical devices, bringing a promising new paradigm for THz modulation, thin-film sensing, and noninvasive material characterization. Refereed/Peer-reviewed

Traditional fighter electrical boxes detection system can not be efficient and accurate implementation in detecting electrical boxes, in order to achieve accurate detection of the electrical box, this paper had designed a detection device consists of upper machine and lower machine system. The system is based on the C8051F120 single chip microcomputer as the core. It is controlled by a machine on and off of the FPGA to drive the relay array to detect the safety status of electric box, through the communication between upper machine and lower machine to display the measurement results. The integrated test system can detect various fighter electrical control boxes, which overcomes the shortcoming of a test equipment in the past can only test a class of products, improves test accuracy and efficiency.

In this paper, we analyze the work principle and control principle of floating panel board type clutch and brake of mechanical press. We focus on analyzing the clutch and brake compatibility test and control. In addition to this, various production machinery drag in most of the motor as power. Motor is controlled through some automatic mode. The most common control mode is relay and contactor, also called electrical control. It is an important part of automatic control. The practitioners must be familiar with this part of knowledge and improve the practical ability. In the electrical control training, we should take positive and effective methods, design the task reasonably, make project and broaden the thinking, to reach the ideal experimental effect.

In this paper, a PLC of FX2N series is used in the redesign of an existed electrical relay - co contactor system. Designing of fault diagnosis system is introduced and together with it relative programs are given. These technical reforms achieved remarkable improvements in simplifying the circuit of the machine system, in enhancing its operation reliability, in increasing the efficiency of fault diagnosis, and in lightening the workload of maintenance staffs.

This paper provides a kind of fault diagnosis method. It introduces the principles of the electrical control of roller Disassembly machine and the phenomenon of sudden power failure in the work. By analyzing a variety of factors that may lead to fault, and taking some appropriate solution, According to calculations, replaced the control transformer as the BK-300 that keep the roller disassembly machine safe and reliable, and avoid the phenomenon of power failure. Point out That the control transformer capacity should meet the required transformer capacity of the control circuit when it has the maximum load; Some control components have been working, when other control components is started, it still remains active.

We study the intervalley scattering in defected graphene by low-temperature transport measurements. The scattering rate is strongly suppressed when defects are charged. This finding highlights "screening" of the short-range part of a potential by the long-range part. Experiments on calcium-adsorbed graphene confirm the role of a long-range Coulomb potential. This effect is applicable to other multivalley systems, provided that the charge state of a defect can be electrically tuned. Our result provides a means to electrically control valley relaxation and has important implications in valley dynamics in valleytronic materials., Comment: 13 pages, 4 figures

Graphene has recently emerged as a viable platform for integrated optoelectronic and hybrid photonic devices because of its unique properties. The optical properties of graphene can be dynamically controlled by electrical voltage and have been used to modulate the plasmons in noble metal nanostructures. Graphene has also been shown to support highly confined intrinsic plasmons, with properties that can be tuned in the wavelength range of 2 μm to 100 μm. Here we review the recent development in graphene-plasmonic devices and identify some of the key challenges for practical applications of such hybrid devices.

Electrical manipulation of lattice, charge, and spin has been realized respectively by the piezoelectric effect, field-effect transistor, and electric field control of ferromagnetism, bringing about dramatic promotions both in fundamental research and industrial production. However, it is generally accepted that the orbital of materials are impossible to be altered once they have been made. Here we use electric-field to dynamically tune the electronic phase transition in (La,Sr)MnO3 films with different Mn^4+/(Mn^3+ + Mn^4+) ratios. The orbital occupancy and corresponding magnetic anisotropy of these thin films are manipulated by gate voltage in a reversible and quantitative manner. Positive gate voltage increases the proportion of occupancy of the orbital and magnetic anisotropy that were initially favored by strain (irrespective of tensile and compressive), while negative gate voltage reduces the concomitant preferential orbital occupancy and magnetic anisotropy. Besides its fundamental significance in orbital physics, our findings might advance the process towards practical oxide-electronics based on orbital., 19 pages, 4 figures. Accepted by Adv. Funct. Mater

Graphene emerges as a viable material for optoelectronics because of its broad optical response and gate-tunable properties. For practical applications, however, single layer graphene has performance limits due to its small optical absorption defined by fundamental constants. Here, we demonstrated a new class of flexible electrochromic devices using multilayer graphene (MLG) which simultaneously offers all key requirements for practical applications; high-contrast optical modulation over a broad spectrum, good electrical conductivity and mechanical flexibility. Our method relies on electro-modulation of interband transition of MLG via intercalation of ions into the graphene layers. The electrical and optical characterizations reveal the key features of the intercalation process which yields broadband optical modulation up to 55 per cent in the visible and near-infrared. We illustrate the promises of the method by fabricating reflective/transmissive electrochromic devices and multi-pixel display devices. Simplicity of the device architecture and its compatibility with the roll-to-roll fabrication processes, would find wide range of applications including smart windows and display devices. We anticipate that this work provides a significant step in realization of graphene based optoelectronics.

Earth provides all the necessary conditions for a wide variety of life forms to survive, and life is present in even the least hospitable parts of the planet. But human life can survive only in conditions that allow our bodies to function properly.

We propose to incorporate in each stage of a quantum-cascade laser a charge accumulation region located outside of the optically active quantum wells. A specially designed intersubband polarization transition in the accumulation region allows electrical control over the modal refractive index, thus providing a mechanism for fast single-mode wavelength tunability

This paper presents experimental evidence of the synchronization between two monolithic chaotic oscillators. These oscillators have been fabricated using gm — C design techniques in a 2-4 μm double-poly n-well CMOS technology. The circuit realizes an oscillator from Chua's circuit family and features electrical control of the parameters in the piecewise-linear function and on-chip tuning of the oscillator natural frequencies. The area of the circuit including pads is 5 mm2 and the power dissipation is less than l-8mW for a symmetrical biasing of ±2.5V.

Liquid crystals (LCs) are intermediate phases between the solid and liquid states of matter whose interesting properties are owing mainly to two remarkable characteristics: i) they can flow as a conventional liquid, ii) they possess positional and orientational order just like those of the solid crystals (de Gennes & Prost, 1993). During the last five decades, LCs have been widely used in optoelectronical devices due to the great ability of changing their properties under the stimuli of external agents as temperature, pressure and electromagnetic fields. It is well known that the propagation of an electromagnetic wave through LCs is a phenomenon that exhibit unique optical properties and highly nonlinear effects (Zel'dovich et al., 1980; Tabiryan et al.,1986).

We demonstrate a quantum well (QW) semiconductor saturable absorber mirror (SESAM) comprising low-temperature grown InGaAs/GaAs QWs incorporated into a p-i-n structure. By applying the reverse bias voltage in the range 0–2 V to the p-i-n structure, we were able to change the SESAM modulation depth in the range 2.5–0.5%, as measured by nonlinear reflectivity of 450 fs long laser pulses with 1065 nm central wavelength, in the pump fluence range 1.6–26.7 μJ/cm2. This electrical control of the modulation depth is achieved by controlling the small-signal loss of the SESAM via quantum-confined Stark effect in the QWs.

In this paper, The electrical control system of a programmable ring lamp and it's application on vision measuring machine are introduced. The lamp is separated into five rings and eight sections. Every rings make the light reflection different because the LED eject light with different angle. Lamp control types are designed according to the controlling requirement. After the control styles have been made clear, a lamp control circuit were designed. We developed a program to control the lamp according to the hardware environment. The lamp control program is integrated into the auto-inspection parts in the vision measuring software. A lot of tests were done on the vision machine which is equipped with it. The results show that the multi-angle lighting and combination lighting styles make the measurement more accurate.

1. Direct galvanic current of 10 to 40 microamperes per square millimeter of cross-section of medium results in anodal determination of rhizoid origin in the differentiated cells of the red alga Griffithsia bornetiana. The current is most effective near the upper end of the range. 2. Within the range used there is an increase in the number of rhizoids produced with increase in current intensity and a decrease in size of rhizoids. 3. Currents of lower intensity require a longer time to produce these effects than comparatively high currents. 4. The orientation of the plants in the electrical field seems to affect the number of rhizoids produced, in that plants with apexes toward the anode produce more rhizoids. 5. Together with anodal rhizoid determination there is migration of chromatophores toward the anodal side of each cell. 6. Displacement of chromatophores (and other cytoplasmic bodies) by the centrifuge does not affect the point of rhizoid origin, but does affect the shoots. 7. Together with anodal determination of rhizoids the algal filaments become graded in color, from bright pink toward the cathode to pale tan toward the anode. 8. Evidence is presented to show that this is not due to a pH change, but to a loss of pigment by chromatophores toward the anode and electrophoresis of the pigment toward the cathode. 9. In conclusion the probability is pointed out that the current acts in morphogenesis by moving particles of different charge.

The role of graphene in mediating the exchange interaction is theoretically investigated when it is placed between two ferromagnetic dielectric materials. The calculation based on a tight-binding model illustrates that the magnetic interactions at the interfaces affect not only the graphene band structure but also the thermodynamic potential of the system. This induces an indirect exchange interaction between the magnetic layers that can be considered in term of an effective exchange bias field. The analysis clearly indicates a strong dependence of the effective exchange bias on the properties of the mediating layer, revealing an effective mechanism of electrical control even at room temperature. This dependence also results in qualitatively different characteristics for the cases involving mono- and bilayer graphene., Comment: 9 pages, 3 figures

Spatiotemporal parameters of gastric electrical control activity such as its amplitude, direction and prop- agation velocity are physiological parameters of distinctive clinical interest due to their potential use for differentiating between the healthy and diseased states of the human stomach. Whereas their time evolution is relatively well behaved in the case of healthy subjects, significant deviations from normal have been observed in patients suffering from a number of gastric diseases such as gastroparesis and gastropathy. For this reason, monitoring ECA parameters noninvasively may offer a useful test for the presence of such diseases whose diagnosis remains problematic. Here, we describe a method for computing ECA direction and orientation from simultaneous, noninvasive magnetogastrographic (MGG) and electrogastrographic (EGG) recordings. We demonstrate how independent component anal- ysis and standard frequency analysis methods can be used to predict the locations and orientations of gastric current dipoles from MGG/EGG data. We compare our MGG-based dipole parameters to analogous ones obtained from simultaneous EGG recordings within the experimental framework of a human model. We find that magnetic recordings are superior in their ability to portray the underlying physiology of the stomach. I. INTRODUCTION The study of gastric motility is of clinical interest due to the relationship between gastrointestinal (GI) disorders and the characteristics of gastric electrical control activity (ECA). ECA is a slow, sinusoidal wave with a frequency of 3 cycles per minute (cpm) originating in the antral gastric region and propagated along smooth muscle cells. Abnormal ECA has been associated with many GI disorders, such as gastroparesis, diabetic gastropathy, and gastric myoelectrical dysrhythmia (12). Two methods for characterizing ECA are electrogastrography (EGG) and magnetogastrography (MGG). EGG involves the placement of cutaneous electrodes on the abdomen to record the bioelectric fields due to ECA at the body surface. The reliability of this procedure has been questioned due to the high dependence of electrical record- ings upon tissue conductivity, the thickness of the abdominal wall, and the variable propagation velocity of ECA (10). MGG involves the positioning of a magnetometer in close proximity to the abdomen to detect the biomagnetic field generated by the electric current of ECA. The measurement of biomagnetic fields is advantageous because they are more strongly dependent on tissue permeability, which is nearly equivalent to that of free space. In this study, we describe our application of principal and independent component analysis (PCA and ICA, respec- tively) for measuring ECA parameters from simultaneous, noninvasive MGG/EGG recordings. Our approach makes use of ICA to isolate the gastric signal, whereafter gastric dipole locations and orientations can be determined from ICA field maps. We compare our results based on magnetic data to analogous ones obtained using simultaneous electrode recordings.

A common rail and injector is controlled by engine ECU (electrical control unit) with many input sensors in HSDI (high speed direct injection) diesel engine. The engine ECU plays the most important role in controlling the diesel engine. It is important to analyze the operations of engine ECU with a variation of data of input sensors. A simulator is necessary in order to observe easily both the operating conditions and fault situations of engine ECU. In this paper, the characteristics of input sensors and their interface circuits in the engine ECU are analyzed, and the system for generating waveforms of all input sensors is implemented by both the 16-bit DSP TMS320LF2407 and host computer. The simulator of engine ECU is applied to a real vehicle in order to investigate the operations of ECU with a variation of input sensors data.

Between 60 and 70 million people in the United States are affected by gastrointestinal disorders. Many of these conditions are difficult to assess without surgical intervention and accurate noninvasive techniques to aid in clinical assessment are needed. Through the use of a superconducting quantum interference device (SQUID) gradiometer, the weak magnetic field generated as a result of muscular activity in the digestive system can be measured. However, the interpretation of these magnetic recordings remains a significant challenge. We have created an anatomically realistic biophysically based mathematical model of the human digestive system and using this model normal gastric electrical control activity (ECA) has been simulated. The external magnetic fields associated with this gastric ECA have also been computed and are shown to be in qualitative agreement with recordings taken from normal individuals. The model framework thus provides a rational basis from which to begin interpreting magnetic recordings from normal and diseased individuals.

Theoretical and experimental results relating to a novel method for achieving direct optical control of a microwave phase shifter are presented, based upon a microwave reflective switch in which on- and off-states are controlled by direct optical illumination of a GaAs FET. Results, hitherto unavailable in the literature, verify previously published models for the GaAs FET as a microwave switch while under electrical control and establish the use of this model to predict the response of the switch under direct optical control over the frequency range 8 to 12 GHz. >

The operation and design of a small press with two-lever control is considered. The design of the press is simple, because it has no electrical control components and few hydraulic control components.

We have studied single-electron turnstile operation in common-gated one-dimensional arrays of four tunnel junctions (three dots) having inhomogeneous junction capacitances. Analytical calculations show that the source-drain voltage range with a current plateau due to single-electron turnstile operation is increased when the outer two tunnel capacitances are adjusted to be smaller than the inner ones. In fact, we have demonstrated in phosphorous-doped silicon-on-insulator field-effect transistors (FETs) that back-gate voltage works to assist the turnstile operation, which is primarily ascribed to electrical control of junction capacitance dispersion, i.e., reduction in outer junction capacitances. As a result, postfabrication control of capacitance dispersion in multijunction FETs can be achieved, resulting in successful turnstile operation.

In this paper, we developed “Mask Key” and “Sub-Pixel Mode ” LC barrier shutter methods by electrical control and combined these two methods to fabricate 15.4 inch 2D/3D arbitrarily switchable autostereoscopic 4-view display successfully. It is the first time 3D display can auto-switch between 2D and 3D mode in the world. Besides, clear 2D and 3D image can be displayed in the same time.

The use of the programmable logic controller has advanced tremendously since its introduction in the late 1960’s. The programmable logic controller, affectionately known as the PLC in today’s industries, was first introduced as an electrical control relay replacer. The purpose of this paper is to assist those who are considering the application of a PLC in their facility to better understand where programmable logic controller technology has advanced to today. Paper published with permission.

The electric perturbation effect to the charge-orbital ordering state has been investigated for Bi1−xSrxMnO3 (x∼0.5). The alignment and rotation of the charge-orbital stripes have been observed in the resistance and the polarizing microscope images at room temperature. These results indicate the possibility of electrical control of the anisotropic properties in the charge-orbital ordering state through the orbital degree of freedom.

A liquid crystal (LC) anamorphic lens is realized using an LC cell with a transparent electrode and a divided electrode with a hole in the center. By applying appropriate potentials on the divided electrode, the LC cell behaves like an optical lens with astigmatic properties. An incident plane lightwave experiences a nearly elliptical profile of phase retardation. The astigmatism is also electrically controllable.

Frequency tuning has been achieved in monolithic modelocked laser diodes through electrical control of the distributed Bragg reflector (DBR) effective length. A 0.5% frequency-tuning range has been obtained, which is wide enough to compensate for the frequency error that results from cavity length uncertainty when the usual cleaving process is used. Low-jitter 9.95328 GHz SDH frequency operation with a 6 ps transform-limited pulse output has been demonstrated.

A multicolor STN-LCD based on the electrical control of birefringence was analyzed and designed on the Poincare sphere. The optical conditions of the cell were chosen from the Poincare sphere. A retardation film provides brighter white, red, blue, and green colors within a small applied-voltage variation. Experimental results show good agreement with numerical calculations.

The centralization of boiler, turbine, generator, and auxiliary electrical control functions has had considerable attention during the past decade in plans and designs of new steam-electric generating plants. The result accomplished is basically a grouping of the several conventional control boards, formerly placed at scattered locations, into a specific area. In the design of the new Morgan Creek Plant for the Texas Electric Service Company, a new approach to centralized control for all combustion, steam, and electrical power facilities has been taken. Of greatest importance is the opportunity afforded for one man to have a comprehensive knowledge of the entire plant performance, and for all important operating functions to be under the control of one operator. Another major advantage is that the new design resulted in approximately a 50% decrease in the control-room area and a substantially larger reduction in linear footage of the control panels. This new and compact centralized control board is of the duplex-type benchboard construction and is shown pictorially in front and rear areas. Each of the two boiler - turbine - generator sections is 7ft long. The entire control board, which includes a 4ft long transmission line control and relay section, is 18ft long. The structure is 7ft 6-in high and 5ft deep between the vertical panels. The bench section protrudes 21in beyond the face of the vertical panels.

Recently, Silicon Controlled Rectifier which is said to be a solid thyratron with control element has been developed and come to be applied to many kinds of control equipments in every field. Losing no time in applying it to the field of illuminating, we, at Toshiba, invented a lamp dimming system two years ago, and have new accomplished its development. This is a report on the outline of the Silicon Controlled Rectifier Lamp Dimming System.This is the first lamp dimming system her produced using SCR in Japan. Being a dimming system of complete quiet type by pure electric controli, t is very small anb light compared with the Autotransformer Lamp Dimming Systein by mechanical control, which is ordinarily used for stages and T. V. studios. Moreover, it has an advantage in remarkably improved flexibility of illuminating effect on stage, as dimming remote control is very simple and does net require 50 much labour.It is expected that this Silicon Controlled Rectifier Lamp Dimming System will be generally adopted for lamp dimming in future.There has been Thyratron Dimming System, Magnetic Amplifier Dimming System and Magnetic-Clutch Dimming System by electrical control. but all of these systems have not widely been used beca use of their low efficiency and complexity of maintenance. Here, we explaines the principle of operation, characteristics and function of the Silicon Controlled Rectifier Lamp Dimming System compared with those of conventional systems.

The electrical phase shift between the current and the applied voltage in a series-resonant circuit as the resonant-circuit tuning is varied is used as the basis of operation for resonant electrical control systems. The author discusses application of such systems to aircraft and industrial problems, and to single and multiphase radio control.

The usefulness of the ordinary moving coil galvanometer is severely limited by the narrow range of adjustment of period, sensitivity, and damping ordinarily provided. By the use of an appropriate electrical circuit, these factors may be adjusted independently and through wide ranges plus or minus. Three separate rheostats control respectively: effective stiffness of suspension, effective damping and effective moment of inertia.

We propose a new integrated interferometric reflector (IIR) with electrical control. The IIR is suitable for incorporation in integrated optical devices as a laser reflector.

Single‐crystal Sr0.75Ba0.25Nb2O6 when used in conjunction with an externally applied electric field is shown to be a sensitive volume holographic medium capable of high‐resolution information storage. Optically induced refractive index changes of 5 × 10−4 have been observed with laser exposure of 14 J/cm2. A simple relation between the applied electric field and optical exposure is determined which allows electrical control of optically induced refractive index change. In addition to control of the optically induced effect it is found that the applied electric field can also be used to control the diffraction efficiency of the holographic reconstruction process.

More than 80 per cent of all industrial hydraulic systems and about 40 per cent of industrial pneumatic power systems are electrically controlled. Why do we find this high percentage of ‘foreign’ control in fluid power, when fluid power itself is quite capable of controlling its own power circuits? The main reason for this phenomenon is the lack of education in the fluid power field itself. For many years electrical control was considered to be ‘the only solution’ for fluid power sequential and combinational control. Electricians and electronic technicians were taught the rules and methods of logic industrial control. This promptly resulted in the use of electrical and electronic switching hardware for fluid power control. Electrical logic is still a compulsory subject in most technical education programs for machine design engineers, draughtsmen and technicians, whereas fluid power logic and methodical fluid power control is only an elective subject or, indeed, not taught at all. It is the aim of this chapter to remove this stigma and to promote the reputation of fluid power as an ideal means of controlling sequential and combinational hydraulic power systems.