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Energy storage is becoming increasingly important for addressing the imbalance between power demand and supply. This study analyzes the performance of a dual system that combines compressed air energy storage (CAES) with a natural gas combined cycle (NGCC). The first was thermal integration, where the exhaust air from the CAES outlet is supplied to the bottoming steam cycle of the NGCC. The second was flow integration where some air from the CAES high-pressure expander outlet is injected to the gas turbine combustor of the NGCC. The reference design conditions were an inlet temperature of 900 °C for the low-pressure expander (LPE) of the CAES and a turbine inlet temperature of 1500 °C for the NGCC. Simple thermal integration could not improve the performance compared to independent operation, but the flow integration improved the power. An 8 % increase in power is expected at 20 % injection. When both the thermal and flow integrations were used simultaneously, the power increment decreased slightly, but the efficiency improved. An increase in the temperature of the LPE improves the CAES performance but reduces the synergistic effect from the integration with the NGCC.

Combined cycles using Solid oxide fuel cells (SOFCs) are expected to provide very high efficiency. The SOFCs are combined with a Gas turbine (GT) or a Gas turbine combined cycle (GTCC). The major SOFC design parameters greatly impact the combined cycle efficiency because the SOFC still produces a majority of the electricity in the combined cycles. In this paper, the influence of the SOFC’s fuel utilization on the efficiency of the combined cycles is carried out using parametric analysis. It is demonstrated and validated that an optimal fuel utilization exists. Four types of SOFC/GT and SOFC/GTCC combined cycles are analyzed. Each combined cycle is found to have an optimal fuel utilization, which is always lower than that of the SOFC-alone system. The main reason is that the turbine inlet temperature rises and thus GT or GTCC power increases with decreasing fuel utilization because of the increased remaining fuel after the cell stack. The value decreases as the power share of the turbomachinery part increases. The peak efficiencies of the SOFC/GT and SOFC/GTCC were predicted to be over 72 % and 76 %. The optimal fuel utilization corresponding to peak efficiency was 0.8 for the SOFC-alone system, 0.7 for the SOFC/GT system, and 0.6 for the SOFC/GTCC system.

We investigated several viable options for combining a gas turbine and a solid oxide fuel cell to achieve very high power generation efficiency. The backbone of the combination is the solid oxide fuel cell/gas turbine dual combined cycle and the solid oxide fuel cell/gas and steam turbine triple combined cycle. The object of analysis is central power plants on the order of hundreds of MW. The gas turbine parameters were taken from an F-class commercial engine, and state-of-the-art parameters of the SOFC were used. In each of the two cycles, the use of a recuperative heat exchanger was considered as a design option. The performance of the combined cycles using the commercial gas turbine was estimated in the first part of the study, and optimal design performance was predicted in the second part assuming a completely revised gas turbine design. Overall, the triple combined cycle was expected to provide better efficiency than the dual combined cycle. Its optimal efficiency was predicted to be over 75%, which is about three percentage points higher than that of the dual combined cycle. The optimal efficiencies of the recuperated and non-recuperated systems were almost the same, which provides flexibility in selecting a system configuration.

A-7-month-old, intact male Shih-Tzu dog was referred with facial dermatitis and stifle pain with 7 days duration. Erythema, hemorrhage, and crusted nodular lesions of the face, swollen eyelids, and otitis externa were observed. A painful response was noted on palpation of the right stifle joint. Impression smears and skin biopsies revealed pyogranulomatous inflammation consistent with canine juvenile cellulitis (CJC). Skin lesions and pain were greatly improved following immunosuppressive corticosteroid therapy. This report firstly describes clinical and histopathological findings as well as treatment responses of CJC in a 7-month-old, domestic dog.

Various options in combining a solid oxide fuel cell (SOFC) with a gas turbine (GT) were compared in this study. The combination of an SOFC with either a simple gas turbine or a gas/steam turbine combined cycle was investigated. For each combined system, the effect of using a recuperative heat exchanger was examined. The design parameters of a state-of-the-art gas turbine for central power stations were used. The GT modeling included modulation of turbine coolant flow depending on turbine working conditions. An SOFC temperature of 900°C was used. Given a currently available reference voltage, pressure-dependent SOFC cell voltage was used. The analysis was divided into two parts. In the first part, the turbine inlet temperature of the reference gas turbine was given and the influence of pressure ratio was analyzed. In the second part, the influence of varying turbine inlet temperature was analyzed to search for optimal design conditions. The results showed that the SOFC/GTCC systems would provide considerably higher efficiencies than the SOFC/GT systems. The optimal pressure ratio in terms of system efficiency is over 30 for non-recuperated systems but is around 10 for recuperated systems. Reducing the extra fuel to the gas turbine combustor improves system efficiency, especially in the SOFC/GT systems. With zero extra fuel, efficiencies of all of the four systems exceed 70%, the highest of which is obtained by the recuperated SOFC/GTCC layout.Copyright © 2015 by ASME

We have successfully reduced threshold voltage variation by combination of co-implantation and laser spike anneal on 45 nm low power SoC platform with conventional poly-Si/SiON gate stack. Doping profiles of CMOSFET channel is modulated through co-implantation of diffusion suppressor. We have explored the possibility of cluster carbon doping in order to minimize junction leakage degradation. Systematic junction profile design for n- and pFET enables us to reduce random dopant variation significantly without compromising standby leakage, drive current and gate oxide integrity, which finally contributes to RO ~5% performance improvement at equivalent Iddq and ensures high yield of SRAM array by reducing beta and gamma ratio variation.

High energy borane (B 2 H 6 ) gas cluster ion beam (GCIB) successfully enables a sub-10nm box-shaped dopant profile without channeling tail, and steep gradient (2.5nm/dec) in lateral direction. pFET using GCIB source/drain extension shows superior suppression of short channel effects and reduces the dependency of drive current on gate overlap capacitance variation for scaled devices. Moreover, the perimeter leakage component in p+/n-well junction was reduced compared to the conventional co-implantation process with pre-amorphization, which might come from novel self-amorphization mechanism by energized clusters without foreign impurities such as Ge and F. For further scaled devices, GCIB can provide more efficient boron activation by laser spike annealing (LSA) while maintaining the scaled extension profile by combination with the reduced temperature spike RTA.

We firstly fabricated on-axis confined structure and evaluated based on 64Mb PRAM with 0.12/spl mu/m-CMOS technologies. Ge/sub 2/Sb/sub 2/Te /sub 5/ was confined within small pore, which resulted in low writing current of 0.4mA. The pore is on-axis with upper and lower contacts, which leads to good scalability of PRAM above 256Mb. The confined structure was relatively insensitive to small cell edge damage effect. The on-axis confined structure is a promising candidate for high density PRAM due to low writing current, good scalability, and insensitiveness to edge damage.

Highly manufacturable 64Mbit PRAM has been successfully fabricated using N-doped Ge/sub 2/Sb/sub 2/Te/sub 5/ (GST) and optimal GST etching process. Using those technologies, it was possible to achieve the low writing current of 0.6 mA and clear separation between SET and RESET resistance distributions. The 64Mb PRAM was designed to support commercial NOR flash memory compatible interfaces. Therefore, the fabricated chip was tested under the mobile application platform and its functionality and reliability has been evaluated by operation temperature dependency, disturbance, endurance, and retention. Finally, it was clearly demonstrated that high density PRAM can be fabricated in the product level with strong reliability to produce new nonvolatile memory markets.

We have integrated a phase-change chalcogenide random access memory, completely based on 0.24 /spl mu/m-CMOS technologies. A twin cell and BL clamping circuits are introduced to enlarge fabrication tolerance and to reduce cell perturbation during reading operation. To draw back current as much as possible, Co salicidation is also applied to transistor formation. By constructing a simple cell structure with Ge/sub 2/Sb/sub 2/Te/sub 5/, we have observed reliable phase-transitions by driving current through MOS transistors. With 100 ns-writing pulses of 2 mA for RESET and 0.6 mA for SET, the device operates successfully with a considerable sensing signal at reading voltage of as low as 0.2 V.

By developing a chalcogenide memory element that can be operated at low writing current, we have demonstrated the possibility of high-density phase-change random access memory. We have investigated the phase transition behaviors as a function of various process factors including contact size, cell size and thickness, doping concentration in chalcogenide material and cell structure. As a result, we have observed that the writing current is reduced down to 0.7 mA.

We have developed a novel cell structure of PRAM with metal interlayer. This novel structure has been proposed to solve the over-programming fail. We have examined the cause of over-programming by simulation of the phase transition of chalcogenide and successfully demonstrated reliable cell operation of this novel structure in writing current level, crystallization speed, and endurance. It can be explained by a model in which the metal interlayer is a local heat sink and the top GST layer is a thermal insulator.

We have fully integrated a nonvolatile random access memory by successfully incorporating a reversibly phase-changeable chalcogenide memory element with MOS transistor. As well as basic characteristics of the memory operation, we have also observed reliable performances of the device on hot temperature operation, endurance against repetitive phase transition, writing imprint, reading disturbance and data retention.

The Ge/sub 2/Sb/sub 2/Te/sub 5/ (GST) thin film is well known to play a critical role in PRAM (Phase Change Random Access Memory). Through device simulation, we found that high-resistive GST is indispensable to minimize the writing current of PRAM. For the first time, we tried to increase the GST resistivity by doping nitrogen. Doping nitrogen to GST successfully reduced writing current. Also, the cell endurance has been enhanced with grain growth suppression effect of dopant nitrogen.

A novel memory device called Scalable Two-Transistor Memory (STTM) has been developed. STTM is a floating gate device with the writing mechanism of direct tunneling through the multiple tunnel junction (MTJ). STTM has potential advantages of scalability, high density, high speed, long data retention, low voltage operation, low power consumption, and good endurability. We have fabricated and successfully demonstrated the memory cell operation of the STTM for the first time. The STTM unit cell fabricated using 0.16 /spl mu/m silicon processing showed the writing speed of /spl sim/100 ns and the data retention time of /spl sim/200 sec. with the operation voltages of -5/spl sim/5 V. Also, we developed a novel architecture for the high-density STTM cell array with an unit cell size of 4F/sup 2/ and a process scheme to fabricate it.