High Pumping Efficiency Research Articles

Furtive quantum sensing using matter-wave cloaks

We introduce the concept of furtive quantum sensing, demonstrating the possibility of concealing quantum objects from matter waves while maintaining their ability to interact and to get excited by the impinging particles. This is obtained by cloaking, with tailored homogeneous metamaterial layers, quantum systems having internal degrees of freedom. The effect is a low-observable quantum sensor with drastically reduced elastic scattering and optimized absorption levels, a concept that opens interesting venues in particle detection, high-efficiency electrical pumping, and quantum information processing.

Evaluation of energy efficiency standards for residential clothes dryers in the USA

This article describes the analysis of monetary and energy savings attributable to various energy efficiency levels considered as potential US federal standards for residential clothes dryers. The analysis examined benefits to both consumers and the nation as a whole. Benefits to consumers were evaluated based on the life-cycle cost of affected appliances and the payback period associated with increased first costs. Benefits to the nation incorporate both energy and financial savings associated with each potential efficiency standard. The analysis incorporated the most current information on field use of clothes dryers, which shows that dryer usage and the moisture in clothes are less than previously thought. The analysis found that high-efficiency heat pump clothes dryers would be cost-effective for nearly one fifth of US households. However, for both electric standard and gas clothes dryers, standards that improve efficiency by 5 % appear to be the highest levels that have a positive net present value of consumer benefit.

Fiber coupler for mode selection and high-efficiency pump coupling

A pump/signal fiber coupler with functions of pump light coupling and high-order-mode suppression is reported. This coupler is composed of pump fibers and a double-clad fiber (DCF) with high pump-coupling efficiency. The core of DCF is microdeformed in the coupling region, which serves mode selection. Theoretical analysis and experimental results verify these functions. In the experiment, the pump-coupling and signal-transmitting efficiency of the coupler were ~98% and ~96%, respectively. This coupler can prevent mode distortion with fundamental mode launching, and improve the fiber laser beam quality with high-order-mode launching.

Er3+ ions doped bismuthate glasses sensitized by Yb3+ ions for highly efficient 2.7 μm laser applications

In present study, we investigated the emissions from visible to mid-infrared and energy transfer processes in Er3+/Yb3+ co-doped germanate–gallate–bismuthate (BGG) glasses. Larger absorption cross-section of Yb3+ ions (7.5×10−21cm2) and enhanced up-conversion, near-infrared and mid-infrared emissions indicate that the introduced sensitized Yb3+ ions can efficiently absorb and transfer pumping energy (980nm) to activate the Er3+ ions. The intensity of 2.7μm emission in Er3+/Yb3+ co-doped samples is about 3 times higher than that of Er3+ singly doped sample. But, the intensity of 2.7μm emission decreases with excessive Yb3+ ions. The optimized ratio of Er3+ and Yb3+ ions for 2.7μm emission is 1.0:0.2 in this BGG glasses. Large emission cross-section σe (−13×10−21cm2 and −9.57×10−21cm2 for 2.7μm and 1.5μm emissions, respectively) is obtained in Er3+/Yb3+ co-doped BGG glasses. According to absorption and emission spectra, energy transfer processes between Yb3+ and Er3+ ions were proposed and main reason for increased up-conversion is the strong excited state absorption (ESA) from excited Er3+ ions at 4I11/2 and 4I13/2 levels. Therefore, high pumping efficiency, intense emissions, large emission cross-section of 2.7μm and 1.5μm emissions and efficient energy transfer processes in this Er3+/Yb3+ co-doped BGG glasses hints its potential applications in laser materials, especially in 2.7μm wavelength.

Corner-pumped Nd:YAG/YAG composite slab continuous-wave 946 nm laser

A corner-pumped type is a new pumping type in the diode-pumped solid-state lasers, which has the advantages of high pump efficiency and favorable pump uniformity. Using the single corner-pumped type, an efficient corner-pumped Nd:YAG/YAG composite slab continuous-wave 946 nm laser is demonstrated in this paper. The compact plane-concave linear cavity configuration is adopted and the cavity length is only 20 mm. When the pumping power is 50 W, the maximal output power can reach as high as 5.29 W with an optical-to-optical conversion efficiency of 10.6% and a slope efficiency of 12%. This laser has a compact structure, simple tuning and low cost, which will have a broad application prospect.

비 막힘형 수중 펌프 임펠러 형상이 펌프 성능에 미치는 영향

This study was performed to develop a high-efficiency submersible nonclogging pump impeller. Toward this end, we simulated the effect of some parameters such as the outlet position of a blade (hI), outlet width of a blade (b2), and hub profile on the pump efficiency by using the commercial codes ANSYS CFX and BladeGen. The results showed that the pump efficiency was proportional up to hI = 38 mm and b2 = 55 mm. It remained constant over these values. However, the head and shaft power were proportional to hI and b2 in the simulated ranges. The effects of hub profile changes on the pump efficiency were relatively small compared to those of the other parameters.

Investigation of the hydraulic design for a high-performance centrifugal pump

We investigated the hydraulic design in terms of high efficiency and good cavitation performance of centrifugal pumps for water supplies. The subject of the investigation was the centrifugal pump, which consists of a suction bend, impeller, diffuser, and discharge volute. The investigation was basically conducted using computational fluid dynamics (CFD) with design of experiments (DOE) and an optimization technique. The suction bend design was implemented first to obtain a uniform flow at the impeller inlet to provide good cavitation performance. We investigated the sensitivity of each parameter value comprising the suction bend configuration for obtaining uniform flow using a parameter design technique with DOE and CFD analyses. The key parameters that enable a better flow field were estimated efficiently and the values of the parameters were adjusted to obtain the optimized configuration. On the other hand, to achieve high performance of the impeller and diffuser shape, the effect of the configuration parameter values on hydraulic loss was also examined using the parameter design based on CFD and a multi-objective optimization technique. The investigation for obtaining a shape achieving high hydraulic efficiency was made practical by taking into account the trade-off of performance characteristics, i.e., performance instability at a low flow rate and gradient of the head curve. When predicting hydraulic performance, it is important to investigate the interaction of flow between the impeller and diffuser to accurately simulate the flow field. The combined analysis of the impeller and diffuser, therefore, was implemented using unsteady flow simulation, and the results were applied to the parameter design using an optimization technique. Finally, the unsteady flow calculation of a complete pump was carried out to confirm the appropriateness of the hydraulic design. The hydraulic performance of the pump was also confirmed using a model pump test. As the result of these investigations, the hydraulic shape of a high-efficiency and high-cavitation centrifugal pump was developed.

A CMOS AC/DC charge pump for a wireless sensor network

An AC/DC charge pump implemented with MOS FETs has been presented for wireless sensor network applications. The proposed AC/DC charge pump can generate a stable output with low power dissipation and high pumping efficiency, which has been implemented in 0.13 μm CMOS technology. The proposed charge pump employs MOSFET diodes with low thresholds, and improves the conversion efficiency. The analytical model of the voltage multiplier, the simulation results, and the chip testing results are presented.

Overview of Pneumatic Pump Reversing Mechanism

Pneumatic pump use compressed gas as power source, outputting straight reciprocating motion. It is widely applied in high pressure airless spray machine. Reversing mechanism is the core component of pneumatic pump. According to the different ways of distributing and reversing gas, pneumatic pump reversing mechanism can be divided into two major categories of pneumatic control type and mechanical type. We summarize the history of the development and the present situation of research and compare various reversing mechanisms in the realization principle, design of structure, manufacturing, vibration noise and cost of production etc. Then we put forward the direction of its research and development, providing theoretical basis for the subsequent development of high quality and efficient pneumatic pump.

Surface plasmon-enhanced lasing in dye-doped cholesteric liquid crystals

This study shows the results of a photonic band-edge laser using dye-doped cholesteric liquid crystals (CLCs) combined with silver (Ag) nanoparticles. When the Ag nanoparticle surface plasmon resonance wavelength matched the excitation source wavelength, the large optical fields provided by surface plasmons increased the fluorescence of dye molecules by enhancing the molecular excitation rate, achieving a low lasing threshold and high pumping efficiency.

Direct and inverse iterative design method for centrifugal pump impellers

A combined direct and inverse iterative design method was developed for the hydraulic design of centrifugal pump impellers. This method is based on the fluid continuity and motion equations and solves for the meridional velocity taking into account the effects of the blade shape on the flow. The blade shape is drawn by point-by-point integration with blade thickening and smoothing using conformal mapping. Two examples designed using the direct and inverse iterative design method are compared to results using the traditional design method with significantly different meridional velocity distributions and three-dimensional blade shapes. Numerical simulations and tests show that the highest pump efficiency is 2.2% higher with this design method than with the traditional design method. The numerical results agree well with the experiments with a smoother flow pattern than with the traditional design, especially in the volute.

High voltage generator circuit with low power and high efficiency applied in EEPROM

This paper presents a low power and high efficiency high voltage generator circuit embedded in electrically erasable programmable read-only memory (EEPROM). The low power is minimized by a capacitance divider circuit and a regulator circuit using the controlling clock switch technique. The high efficiency is dependent on the zero threshold voltage (Vth) MOSFET and the charge transfer switch (CTS) charge pump. The proposed high voltage generator circuit has been implemented in a 0.35 μm EEPROM CMOS process. Measured results show that the proposed high voltage generator circuit has a low power consumption of about 150.48 μW and a higher pumping efficiency (83.3%) than previously reported circuits. This high voltage generator circuit can also be widely used in low-power flash devices due to its high efficiency and low power dissipation.

Wireless Front-End With Power Management for an Implantable Cardiac Microstimulator

Inductive coupling is presented with the help of a high-efficiency Class-E power amplifier for an implantable cardiac microstimulator. The external coil inductively transmits power and data with a carrier frequency of 256 kHz into the internal coil of electronic devices inside the body. The detected cardiac signal is fed back to the external device with the same pair of coils to save on space in the telemetry device. To maintain the power reliability of the microstimulator for long-term use, two small rechargeable batteries are employed to supply voltage to the internal circuits. The power management unit, which includes radio frequency front-end circuits with battery charging and detection functions, is used for the supply control. For cardiac stimulation, a high-efficiency charge pump is also proposed in the present paper to generate a stimulated voltage of 3.2 V under a 1 V supply voltage. A phase-locked-loop (PLL)-based phase shift keying demodulator is implemented to efficiently extract the data and clock from an inductive AC signal. The circuits, with an area of 0.45 mm², are implemented in a TSMC 0.35 μm 2P4M standard CMOS process. Measurement results reveal that power can be extracted from the inductive coupling and stored in rechargeable batteries, which are controlled by the power management unit, when one of the batteries is drained. Moreover, the data and clock can be precisely recovered from the coil coupling, and a stimulated voltage of 3.2 V can be readily generated by the proposed charge-pump circuits to stimulate cardiac tissues.

Design of a Vacuum Pumping System for the Closed Helical Divertor for Steady State Operation in LHD

A vacuum pumping system is installed in a Closed Helical Divertor (CHD) in the Large Helical Device (LHD) at the National Institute for Fusion Science for active control of the peripheral plasma density and impurity suppression in the core plasma. In the CHD configuration, the distance between the pumping system and the divertor plates (heat and particle source) is very short (only ∼0.1 m). One of the major issues in designing the pumping system is the reduction of heat load by radiation and thermal conduction due to the neutral particles being released from the heated divertor plates while keeping a high pumping efficiency. Here the heat load and the pumping efficiency are analyzed using a neutral particle transport simulation and a finite element method based software for multi-physics analysis. We propose a new design for a pumping system with an expanded area of the inlet of the water-cooled blinds and a bottom slit beneath the pumping system. This increases the pumping efficiency by approximately 60% over that of our previous design. It also predicts that the increase in heat load on the pumping system for the new design would be reasonably suppressed by a buffer plate with high emissivity on the surface of the vacuum vessel on the inboard side of the torus.

High-Efficiency CTS Charge Pump Using Three-Level Addressing Method

This paper proposes a new addressing method for high-efficiency switching-capacitor DC-DC voltage converter based on combination of CTS (charge-transfer-switch) charge pump and cross-coupled output stage is proposed in order to get a high output power and pump-efficiency. By using three level addressing methods, it can increase both of pump-efficiency and power-efficiency. The proposed three level addressing mixed-structure charge pump can operate at as high as 1MHz switching-frequency on the 0.1 μF pump-capacitors. Simulation by using HSPICE level 3 model shows that our work can convert the input low DC-voltage (Vin=1.5V) up near to 11.26 times of it (VOUT=16.9V), so that more output power can be generated with a little power loss. The newly proposed addressing method for DC-DC charge pump circuit is suitable for various low-voltage applications.

High Pumping Gain Dickson Charge Pump Using Bootstrapped Technique

This paper proposed a bootstrapped type high-efficient charge pump circuit based on the Dickson charge pump for high output power and pump-efficiency. By using bootstrapped technique, it can increase both of pump-efficiency and power-efficiency. The proposed bootstrapped based charge pump can avoid the threshold voltage drop and enable to generate a higher output voltage. Simulation by using HSPICE level 3 model shows that for conventional Dickson charge pump, it convert the input low DC-voltage (Vin=1.5V) up to 3.8 times of it (VOUT=5.77V), the pump efficiency was 76.93%. Our work, however, can convert the low input DC-voltage (Vin=1.5V) up near to 4.4 times of it (VOUT=6.62V), pump efficiency can reach up to 88.26%.

Numerical and experimental investigation of lubricating oil flow in a gerotor pump

Gerotor pumps are widely used in the automotive industry for engine oil lubrication, due to their high volumetric efficiency and smooth pumping action. In many cases, the lubricating oil from the sump is mixed with contaminants, such as dust and tiny solid particles, or becomes thickened, due to aging. These problems will lead to critical situations, such as increased noise, enhanced wear and erosion, and poor lubrication of the engine. These critical situations were studied by conducting a detailed CFD integrated investigation on a gerotor pump’s performance at different operating conditions in three phases, and the results are presented in this paper. In first phase, a CFD model of a gerotor pump was developed with a dynamic mesh for the rotary movement of both the inner and outer rotors. The effects on pump flow rate of important parameters, such as rotor speed, fluid viscosity and number of ports, were simulated using non-contaminated oil at room temperature and an elevated temperature of 140oC. The relationship between flow rate and pressure at different rotor speeds was predicted and validated with test data for further parametric study. The pressure ripples at different time steps were measured at different angular positions of the rotors to examine the model accuracy. It was found that the flow rate increased and pressure pulsation, as well as flow recirculation, was reduced when ports were added to the cover plate. A suction pipe with a strainer was added for the second phase to capture the undesired changes in flow behavior, such as cavitation, which is caused by negative suction at the inlet region of pump. A suitable size for the inlet suction pipe for this pump was chosen after performing tests to characterize the flow behavior with single and double ports. Next, the relationship between pressure drop and strainer porosity was determined using different porosity values for the strainers. In the final phase, oil with different concentrations of solids was simulated to measure the effect of solid particles on flow rates and pressure losses. It was observed that the intensity of the recirculation was reduced at the suction end at the higher concentration of 0.04%, due to particle inertial effects. It was also found that particle size distribution affected the overall efficiency and pressure head of the pump.

Orthogonal Test Design and Numerical Simulation of 100QJ10 Type Deep-Well Pump

In this paper in order to develop high efficiency and high head deep-well pump, a L9 (34) orthogonal experiment was performed with four factors and three values including outlet angle, outlet width, the outside diameter of impeller back shroud, etc. 9 impellers were designed. The whole flow field of new-type two-stage deep-well pump at the operating point for design was simulated by FLUENT 6.2 using the standard model, SIMPLEC algorithm, second-order upwind scheme to solve, and analyze the independent of the number of the grid. 9 groups of the efficiency and head in design scheme were obtained. The effects of geometrical parameters on efficiency, head were researched using Latin square test method. The primary and secondary factors of the design parameters were acquired by way of variance analysis. According to the test result, an optimum program to further design was put forward. After manufactured and tested, the efficiency and head of the final optimal design models were significantly improved. The productions show good energy saving and material saving characters and could replace traditional pumps for deep well in the future, the comprehensive technical indicators achieve international advanced levels. The results would be instructive to the design method of new-type deep well pump.

消逝波激励及增益耦合光纤三色激光辐射

A Whispering-Gallery-Mode tricolor fiber laser is demonstrated by pumping and gain coupling with evanescent waves. The pump light is longitudinally coupled into a bare optical fiber immersed in a dye solution of lower refractive index. The dye molecules around the bare fiber are excited by the evanescent waves of pump light when their propagating along the fiber in a total internal reflection. Because the excited molecules are located within the evanescent field of Whispering-Gallery-Mode, a good spatial overlap between the dye gain and the evanescent field leads to a high pumping efficiency and a longer gain distance along the fiber. Once the bare fiber is inserted into three glass tube filled with Rhodamine 640, Coumarin 500 and Stilbene 420 dye solutions, respectively, Whispering- Gallery-Mode lasing oscillations at the wavelengths of 622-632 nm, 504-518 nm and 427-434 nm occur simultaneously, and a tricolor lasing emission is achieved in a single optical fiber. The relationship between produced length of lasing emission and pumping energy has also been investigated.

진공펌프 조합에 의한 반도체공정 진공시스템 진공특성 전산모사

Effect of pump combinations on the vacuum characteristics of vacuum system was simulated for optimum design of system. In this investigation, the feasibility of modelling mechanism for VacSimMulti simulator was proposed. Simulation results of various pumping combinations showed the possibilities and reliabilities of simulation for the performance of vacuum system in specific semiconductor processing. Simulation of roughing pump presented the expected pumping behaviors based on commercial specifications of employed pumps. Application of booster pump exhibited the high pumping efficiency for middle vacuum range. Combinations of optimum backing pump for diffusion and turbo vacuum system were obtained. And, the predictable characteristics of process application of both simulated systems were also acquired.