Simple Power Consumption Research Articles

Ultra low power design of multi-valued logic circuit for binary interfaces

From the dawn of the computer age, man has mass produced binary components for computers, due to which ternary or higher radix computers are not yet commercially used. It has been proved that ternary logic can be more efficient than binary logic and there are many devices in development that operate on more than two internal states. Therefore an efficient method to produce multi-valued logic on the basis of binary input provided is needed. In this article, an effective, simple, flexible, and low power consumption implementation has been proposed that can convert any binary number to a number of chosen radix. The proposed design is implemented in 32 nm TSMC CMOS. The proposed design is then evaluated in power/delay space and its performances are compared with the latest state of art designs. The proposed circuit exhibits power saving up to 92% over previous models.

Room-Temperature Manipulation of Magnetization Angle, Achieved with an All-Solid-State Redox Device.

An all-solid-state redox device, composed of magnetite (Fe3O4) thin film and Li+ conducting electrolyte thin film, was fabricated for the manipulation of a magnetization angle at room temperature (RT). This is a key technology for the creation of efficient spintronics devices, but has not yet been achieved at RT by other carrier doping methods. Variations in magnetization angle and magnetic stability were precisely tracked through the use of planar Hall measurements at RT. The magnetization angle was reversibly manipulated at 10° by maintaining magnetic stability. Meanwhile, the manipulatable angle reached 56°, although the manipulation became irreversible when the magnetic stability was reduced. This large manipulation of magnetic angle was achieved through tuning of the 3d electron number and modulation of the internal strain in the Fe3O4 due to the insertion of high-density Li+ (approximately 1021 cm-3). This RT manipulation is applicable to highly integrated spintronics devices due to its simple structure and low electric power consumption.

Design and Simulation of a Collaborative Propulsion System for the Underwater Robot

The design of propulsion system is a very critical task because it determines the performance of underwater robots, such as maneuverability and endurance and so on. Generally, it is a challenge to develop a propulsion system which can make tradeoff among multiple degree-of-freedom (DOF) motions, simple and compact structure and low power consumption. Thus, we are motivated to propose a collaborative propulsion system for the underwater robot and its unique reconfigurable structure makes vectorial propulsion possible.

Designing programmable current-mode Gaussian and bell-shaped membership function

In this paper, a procedure is proposed to implement a novel and effective Gaussian-shaped and Bell-shaped membership function. The circuit is designed in a current mode. Therefore, the power consumption has been decreased. Higher power supply rejection ratio is also achieved by the use of a differential structure. The most important aims are to design simple, accurate and low power consumption circuits. The proposed circuit operates in the saturation region. Therefore, high-accuracy, as well as the high-speed performance and independency to the temperature variations, are obtained. Programmability, power consumption and parameters variations of the proposed circuit are also presented. The simulations are done in 0.18 µm CMOS technology.

Silicon-doped indium oxide – a promising amorphous oxide semiconductor material for thin-film transistor fabricated by spin coating method

Silicon-doped indium oxide (In-Si-O or ISO) has been investigated as the channel material of thin-film transistor (TFT) for the application of next generation flat panel displays. Because solution processing is simple, low cost and low power consumption in comparison with physical vapour deposition, it is a potential candidate for TFTs fabrication. We have been exploring research on TFT using ISO system via spin coating method. In this work, the performance of 3 at.% Si-doped indium oxide TFT has been improved with the highest mobility of 3.8 cm2/Vs without the passivation layer.

High-sensitivity detection of H2S by In2O3/C composite prepared by inert-ambient sealed-tube pyrolysis

Indium acetylacetonate, a β-diketonate complex, was pyrolyzed at 700 °C in inert ambient in a sealed quartz tube, to yield a powder composite of nanocrystalline In2O3 and elemental carbon (In2O3/C), as deduced from characterization by powder X-ray diffraction and Raman spectroscopy. Scanning electron microscopy shows that the metal oxide is embedded in micrometer-sized spherical structures, composed largely of carbon. The spherical entities are likely formed when the metal complex melts, decomposes, and vaporizes during pyrolysis, with the vapour condensing into spherical “droplets” as the sealed tube cools gradually to room temperature. The In2O3/C composite was tested (in pellet form) as a gas sensor, specifically the conductometric sensing of H2S. At 5 ppm of H2S, the composite shows a high response of 225% at 250 °C, with the response and recovery being swift (~ 5 s and ~ 15 s, respectively). At 250 °C, the detection limit is found to be of 500 ppb of H2S, with selectivity over NH3, NO2, CH4, and SO2 being considerable. The In2O3/C sensor also displays good cyclability. When carbon in the composite is removed by annealing it in air (550 °C, 60 min), the resulting In2O3 powder (in pellet form) shows a much poorer response to H2S at 250 °C (25% to 5 ppm), illustrating that the elemental carbon in In2O3/C enhances sensitivity to H2S. The advantages of a simple fabrication process and low power consumption make the carbonaceous composite sensor potentially useful.

Temporal Encoding to Reject Background Signals in a Low Complexity, Photon Counting Communication Link.

Communicating information at the few photon level typically requires some complexity in the transmitter or receiver in order to operate in the presence of noise. This in turn incurs expense in the necessary spatial volume and power consumption of the system. In this work, we present a self-synchronised free-space optical communications system based on simple, compact and low power consumption semiconductor devices. A temporal encoding method, implemented using a gallium nitride micro-LED source and a silicon single photon avalanche photo-detector (SPAD), demonstrates data transmission at rates up to 100 kb/s for 8.25 pW received power, corresponding to 27 photons per bit. Furthermore, the signals can be decoded in the presence of both constant and modulated background noise at levels significantly exceeding the signal power. The system’s low power consumption and modest electronics requirements are demonstrated by employing it as a communications channel between two nano-satellite simulator systems.

Development of a simple power consumption model of information technology (IT) equipment for building simulation

The IT equipment power consumption estimated by building simulation software is much higher than the actual case, but there are no simple solutions for building engineers to reduce the bias in data center models in building simulation. This paper address this issue by proposing a simple model of IT equipment load. The model estimates the IT equipment load based on critical control inputs of the IT equipment such as its processor utilization rate and on/off status, and a survey of literature for the ordinary values of these IT equipment control variables is conducted to facilitate its uses by building engineers. A case study was conducted with building models of large offices with lots of IT equipment, and the estimated annual building energy use was reduced by more than 30% in all three cases. This shows that the conventional constant thermal load model overestimates the IT equipment load and the IT equipment model improves the accuracy of modeling of data centers in building simulation by modeling the changes of the load with the status of the servers.

Improving the performance of micro pumps by reduction of flow pulsation for drug delivery application

Piezo-electrical diaphragm type mechanical micro pump (PZT micro pump) is one of the Micro Electro Mechanical System (MEMS) device dominant among all micro pumps because of its simple structure and low power consumption. PZT micro pump is widely used for drug-delivery systems basically-injection of glucose to diabetic patients and blood transportation, and also in other areas such as bioengineering, fuel drop generator for automobile heaters, micro metering valves for fuel injection system, etc. Fluid flow from these micro pumps is in the form of small discrete volumes with flow pulsating. But in application such as drug delivery system it may be required to have a continuous fluid flow without any flow pulsation. Therefore to have an adaptability of these micro pumps for drug-delivery applications, problem of pulsating flow can be overcome by proper sequencing of these pumps. In the present paper, an attempt has been made to study the multiple PZT micro pumps operated in parallel connection with sequential switching in order to reduce the flow pulsation. The flow pulsations have been measured in terms of pressure pulsation and average flow rate and obtained results are presented systematically in the paper.

Characteristics of microdischarge plasma jet in water and its application to water purification by bacterial inactivation

Abstract A microdischarge jet with a simple structure and low power consumption was developed, and we investigated its characteristics in a stable plasma jet in water, as well as the effect of the generated active radicals on bacterial disinfection. Sterilization experiments were performed using air and nitrogen plasma jets, and the sterilization rates of Escherichia coli were 99.99% and 66.7%, respectively. Active radicals such as H2O2, OH, NO, and NO2, which could contribute to sterilization, were produced when the plasma jet was generated in water. In particular, a comparison of the results obtained with the air- and nitrogen-plasma jets showed that the radical concentration was highly influenced by sterilization.

Heat and mass transfer and hydrodynamics in swirling flows (review)

Research results of Russian and foreign scientists of heat and mass transfer in whirling flows, swirling effect, superficial vortex generators, thermodynamics and hydrodynamics at micro- and nanoscales, burning at swirl of the flow, and technologies and apparatuses with the use of whirling currents for industry and power generation were presented and discussed at the “Heat and Mass Transfer in Whirling Currents” 5th International Conference. The choice of rational forms of the equipment flow parts when using whirling and swirling flows to increase efficiency of the heat-power equipment and of flow regimes and burning on the basis of deep study of the flow and heat transfer local parameters was set as the main research prospect. In this regard, there is noticeable progress in research methods of whirling and swirling flows. The number of computational treatments of swirling flows’ local parameters has been increased. Development and advancement of the up to date computing models and national productivity software are very important for this process. All experimental works are carried out with up to date research methods of the local thermoshydraulic parameters, which enable one to reveal physical mechanisms of processes: PIV and LIV visualization techniques, high-speed and infrared photography, high speed registration of parameters of high-speed processes, etc. There is a problem of improvement of researchers’ professional skills in the field of fluid mechanics to set adequately mathematics and physics problems of aerohydrodynamics for whirling and swirling flows and numerical and pilot investigations. It has been pointed out that issues of improvement of the cooling system and thermal protection effectiveness of heat-power and heat-transfer equipment units are still actual. It can be solved successfully using whirling and swirling flows as simple low power consumption exposing on the flow method and heat transfer augmentation.

Liquid metal enabled microfluidics.

Several gallium-based liquid metal alloys are liquid at room temperature. As 'liquid', such alloys have a low viscosity and a high surface tension while as 'metal', they have high thermal and electrical conductivities, similar to mercury. However, unlike mercury, these liquid metal alloys have low toxicity and a negligible vapor pressure, rendering them much safer. In comparison to mercury, the distinguishing feature of these alloys is the rapid formation of a self-limiting atomically thin layer of gallium oxide over their surface when exposed to oxygen. This oxide layer changes many physical and chemical properties of gallium alloys, including their interfacial and rheological properties, which can be employed and modulated for various applications in microfluidics. Injecting liquid metal into microfluidic structures has been extensively used to pattern and encapsulate highly deformable and reconfigurable electronic devices including electrodes, sensors, antennas, and interconnects. Likewise, the unique features of liquid metals have been employed for fabricating miniaturized microfluidic components including pumps, valves, heaters, and electrodes. In this review, we discuss liquid metal enabled microfluidic components, and highlight their desirable attributes including simple fabrication, facile integration, stretchability, reconfigurability, and low power consumption, with promising applications for highly integrated microfluidic systems.

Logic gates realized by nonvolatile GeTe/Sb2Te3 super lattice phase-change memory with a magnetic field input

Nonvolatile memory devices or circuits that can implement both storage and calculation are a crucial requirement for the efficiency improvement of modern computer. In this work, we realize logic functions by using [GeTe/Sb2Te3]n super lattice phase change memory (PCM) cell in which higher threshold voltage is needed for phase change with a magnetic field applied. First, the [GeTe/Sb2Te3]n super lattice cells were fabricated and the R-V curve was measured. Then we designed the logic circuits with the super lattice PCM cell verified by HSPICE simulation and experiments. Seven basic logic functions are first demonstrated in this letter; then several multi-input logic gates are presented. The proposed logic devices offer the advantages of simple structures and low power consumption, indicating that the super lattice PCM has the potential in the future nonvolatile central processing unit design, facilitating the development of massive parallel computing architecture.

Simulation of the Core Technology of a Greenhouse-Monitoring System Based on a Wireless Sensor Network

To solve the topology structure of a greenhouse environment-monitoring system and the ductility of joints, this study presents a design of a greenhouse-monitoring system based on the ZigBee wireless sensor network (WSN). The hardware and software designs of the network node are provided, and the process of the ZigBee network coordinator is elucidated. The system uses the microcontroller unit PIC18F4620CC2420 wireless transceiver module to send and receive data. Data from temperature and humidity sensors are collected using an inter-integrated circuit bus through the ZigBee network transmission to the monitoring platform. Test results show that the system has the advantages of having a simple structure, flexible nodes, and low power consumption. It can effectively monitor the temperature and humidity in a wireless environment. WSNs considerably help in greenhouse environment monitoring. The use of advanced technology to control greenhouse temperature and humidity can satisfy the optimum growth environment of greenhouse crops and effectively improve the yield and quality of crops. The application of WSNs in greenhouse monitoring is significant to the development of modern and precision agriculture in China.

Performance evaluation of an air-breathing high-temperature proton exchange membrane fuel cell

The air-breathing proton exchange membrane fuel cell (PEMFC) is of great interest in mobile power sources because of its simple system design and low parasitic power consumption. Different from previous low-temperature air-breathing PEMFCs, a high-temperature PEMFC with a phosphoric acid doped polybenzimidazole (PBI) membrane as the polymer electrolyte is designed and investigated under air-breathing conditions. The preliminary results show that a peak power density of 220.5mWcm−2 at 200°C can be achieved without employing any water managements, which is comparable to those with conventional Nafion® membranes operated at low temperatures. In addition, it is found that with the present cell design, the limiting current density arising from the oxygen transfer limitation is around 700mAcm−2 even at 200°C. The short-term durability test at 200mAcm−2 and 180°C reveals that all the cells exhibit a gradual decrease in the voltage along with a rise in the internal resistance. The degradation rate of continuous operation is around 58.32μVh−1, which is much smaller than those of start/stop cycling operations.

Sub-100 nm Ferroelectric-Gate Thin-Film Transistor with Low-Temperature PZT Fabricated on SiO2/Si Substrate

Thin film transistor which uses an active oxide-semiconductor channel and a ferroelectric-gate insulator, so-called FGT, has wide attention for the application of a new nonvolatile memory owing to its prominent features such as simple structure, high speed and low power consumption. Previously, we have reported on demonstration of the FGTs operation, but the ones developed have channel lengths (LDS) more than 100 nm, which should be reduced for high-density storage in integration circuits. In this work, a new technique has been proposed to fabricate the sub-100 nm FGT using low-temperature PZT thin film, whose source-drain gap would be mainly created from electron beam lithography, dry etching and ashing. With the new technique, the memory functionality of the fabricated sub-100 nm FGTs are comparable with that of the sub-μm sized FGT. In particular, the ON/OFF current ratio is about 104–105, the memory window is 2.0, 1.8 and 1.7 V, and the field-effect mobility is 0.12, 0.07 and 0.16 cm2V−1s−1 for the LDS of 100, 50, and 30 nm, respectively.

Smart metering application for power efficiency studies

Improving the energy efficiency of our Institute’s data center is an ambitious challenge for our research teams. Understanding how the energy is consumed in each segment of the system becomes fundamental in order to minimize the overall energy consumed by the system itself. In this paper, we propose an experimentally–driven approach to develop a simple and accurate power consumption and temperature monitoring system. In this work we focused our attention on the monitoring, measurement of the energy consumption patterns of our data center system, at INCDTIM Cluj-Napoca, Romania.

An Extended Simple Power Consumption Model for Selecting a Server to Perform Computation Type Processes in Digital Ecosystems

In information systems, applications are required to be realized in the digital ecosystems, high performance systems, and scalable systems. In these applications, a client first selects a server in a cluster of servers and issues a request to the server. The request is performed as a process in the server. In this paper, we consider a computation process which mainly consumes the central processing unit (CPU) resources. Cooling devices, such as fans, consume the electric power in addition to the CPU of a server. The rotation speed of a fan is revved up in servers in order to decrease the temperature of a server. Thus, the total power consumption of a server depends on not only computational devices such as a CPU, but also cooling devices. We discuss an extended simple power consumption (ESPC) model of a server with a multicore CPU and cooling devices to perform computation type processes. It is critical to discuss how to select a server for each request issued by a client in order to not only achieve performance objectives, but also reduce the total power consumption of a system based on the ESPC model. An improved power consumption laxity-based (IPCLB) algorithm for selecting a server is proposed in this paper, where the minimum power to be consumed is used to perform the process. We evaluate the ESPC model and IPCLB algorithm in terms of power consumption and elapse time.

Low-voltage low-power multifunction current-controlled conveyor

In this study, low-voltage low-power multifunction current-controlled conveyor (CCCII) is introduced. Multifunction current conveyors are able to achieve various CCCII structures with a small modification in the circuit. The proposed circuit required ±0.5 V as a power supply, a simple circuit structure and low power consumption. The power consumption is only 4.8 µW. Low-voltage operation is achieved by using changeable threshold voltage and PMOS level-shifter current mirror. This circuit is able to operate as CCCII± with both positive and negative intrinsic resistance, which have a wide tunable range with a small modification in the circuit connections.

Study on time reverse mirror in underwater acoustic communication

Time reversal mirror (TRM) can adaptively match the sound channel without any prior knowledge. In this paper, active TRM, passive TRM and virtual TRM which are all based on a single array element and the application of TRM in the underwater acoustic communication including single-user communication and multi-user communication are studied. Single sensor TRM which has time compression performance lacks array processing space gain, however, it can meet the requirements for underwater acoustic communication nodes being in the pursuit of simple structure and low power consumption. It is verified that TRM could focus multipath signal and achieve real-time adaptive channel equalization through computer simulation and test results, which could suppress the inter-symbol interference(ISI) and improve the signal-to-noise ratio(SNR).