Dynamic Error-Compensated Fixed-Width Booth Multiplier Based on Conditional-Probability of Input Series

This paper proposes a dynamic error-compensated circuit for a fixed-width Booth multiplier based on the conditional probability of input series (CPIS), which enables high-speed operation and low circuit overhead. The dynamic compensated value is produced directly from the multiplier of input series simultaneously with the Booth encoder and therefore does not affect the critical path. The compensated formula is derived using a mathematical probability model, rather than time-consuming simulation. This formula is a function of bit-length of the multiplier; thus, the compensated circuit is easily implemented for bit-length of 32, 64, or longer. Accuracy-efficiency, which indicates the signal-to-noise ratio per unit area and unit delay, is included for ease of comparison. Compared with previous works, the greatest advantage of the proposed CPIS is high speed. Furthermore, the proposed CPIS achieves higher accuracy-efficiency. Implemented using the TSMC 0.18-\(\upmu \)m CMOS process, the proposed 32-bit Booth multiplier has an operation frequency of 50 MHz with power consumption of 7.3 mW.     

Reducing nitric oxide into nitrogen via a radio-frequency discharge

NO/N(2)/O(2)/H(2)O mixtures are usually converted into HNO(3) and/or NO(2) using different discharge approaches. In this study, a radio-frequency discharge was successfully used to reduce NO mainly into N(2) at a low pressure (4kPa). The influences of experimental parameters, including carrier gas, inlet concentration of NO, O(2), steam, and applied power, are discussed. At least 95.7% of the total N atoms converted from NO into N(2). Other traces of byproducts were N(2)O and HNO(2), but neither HNO(3) nor NO(2) were detected. In addition, conversion of NO apparently increased with elevated applied power or decreased inlet concentration of O(2), reaching 92.8% and 74.2% for the NO/N(2)/O(2) (2%) and NO/N(2)/O(2) (6%)/H(2)O (10%) mixtures, respectively, at 120W. In addition, from the optical emission spectra, a large amount of N(2) (first positive band and second positive band) and NO (gamma system) were observed, and the important reactions for NO removal and N(2) formation are proposed.     

Soil dioxins levels at agriculture sites and natural preserve areas of Taiwan

In this study, agriculture soil in Taiwan has been sampled and analyzed to determine the background level of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/DF) in the agricultural and nature preserve areas. Another objective is to investigate relationship between soil characteristics and air deposition in Taiwan. The results indicate that in nature preserve areas the topsoil shows an extraordinary profile of PCDD/DF compared to that in the air deposition. The PCDD/DF levels of the low-contaminated agricultural soils are compatible with those of the nature preserves soils. However, in the highly-contaminated agricultural soils, there is an abrupt jump in their concentrations, 10-100 times higher. The overall I-TEQ values of the background topsoils range from 0.101 to 15.2 ng I-TEQ/kg. Near industrial/urban areas in Taiwan the PCDD/DF are slightly higher compared to those in the low concentration group. Typically, the PCDD/DF background values found in this survey fall in the 90% confidence interval and can thus, be deemed the background levels in Taiwan. Ninety-five percent of these data are below the European and American soil standard of 10 ng I-TEQ/kg d.w. The PCDD/DF profile with one neighborhood soil sample was shown no significant difference.     

High-efficiency host free deep-blue organic light-emitting diode with double carrier regulating layers

A bright high-efficiency host-free deep-blue organic light-emitting diode (OLED) is demonstrated. Without the aid of any carrier regulating layer, the deep-blue OLED shows a power efficiency of 1.7 lm W⁻¹ with CIE coordinates of (0.143, 0.098) at 1000 cd m⁻². The respective power efficiency is increased from 1.7 to 2.1 and 2.2 lm W⁻¹ as a single- and double-carrier regulating layers were incorporated. The respective peak luminance also increases from 5250 to 7620 and 9130 cd m⁻², an increment of 45% and 74%. The marked brightness improvement may be attributed to the incorporated carrier regulating layers that effectively lead carriers to recombine in a wider zone. Moreover, the blue emission can be hypsochromic shifted by varying the incorporation position of the carrier regulating layer and the emissive layer thickness.     

Reduction of energy cost and CO2 emission for the furnace using energy recovered from waste tail-gas

In this research, the waste tail gas emitted from petrochemical processes, e.g. catalytic reforming unit, catalytic cracking unit and residue desulfurization unit, was recovered and reused as a replacement of natural gas (NG). On-site experimental results show that both the flame length and orange-yellowish brightness decrease with more proportion of waste gas fuel added to the natural gas, and that the adiabatic temperature of the mixed fuel is greater than 1800 °C. A complete replacement of natural gas by the recovered waste gas fuel will save 5.8 × 10⁶ m³ of natural gas consumption, and 3.5 × 10⁴ tons of CO₂ emission annually. In addition, the reduction of residual O₂ concentration in flue gases from 4% to 3% will save 1.1 × 10⁶ m³ of natural gas consumption, reduce 43.0% of NO_x emission, and 1.3 × 10³ tons of CO₂ emission annually. Thus, from the viewpoint of the overall economics and sustainable energy policy, recovering the waste tail gas energy as an independent fuel source to replace natural gas is of great importance for saving energy, reducing CO₂ emission reduction, and lowering environmental impact.     

Improving cost-effectiveness for the furnace in a full-scale refinery plant with reuse of waste tail gas fuel

The waste tail gas fuel emitted from refinery plant in Taiwan e.g. catalytic reforming unit, catalytic cracking unit and residue desulfurization unit, was recovered and reused as a replacement fuel. In this study, it was slowly added to the fuel stream of a heater furnace to replace natural gas for powering a full-scale distillation process. The waste tail gas fuel contained on average 60 mol% of hydrogen. On-site experimental results show that both the flame length and orange-yellowish brightness decrease with increasing proportion of waste gas fuel in the original natural gas fuel. Moreover, the adiabatic flame temperature increases as the content of waste gas fuel is increased in the fuel mixture since waste gas fuel has a higher adiabatic flame temperature than that of natural gas. The complete replacement of natural gas by waste gas fuel for a heater furnace operating at 70% loading (i.e. 3.6 × 10⁷ kcal/h of combustion capacity) will save 5.8 × 10⁶ m³ of natural gas consumption, and 3.5 × 10⁴ tons (or 53.4%) of CO₂ emission annually. Recovering and reusing the waste tail gas fuel as natural gas replacement will achieve tremendous savings of natural gas usage and effectively lower the emission of carbon dioxide.     

Design of low-voltage cmos low-noise amplifier with image-rejection function

A new design is presented that combines a low-noise amplifier (LNA) with an on-chip filter instead of external filter to eliminate image signal based on TSMC 0.18 mum CMOS technology. The fully integrated 5.9 GHz LNA exhibits 15.2 dB gain, 3.2 dB noise figure, better than -15 dB input and output return loss, and -27 dB image rejection. The circuit operates at a supply voltage of 1 V and consumes only 6.1 mW power.     

A novel two-beam scanning active leaky-wave antenna

A novel two-beam scanning active leaky-wave antenna (LWA) has been developed. This LWA with a two-terminal feeding microstrip line structure is integrated with a varactor-tuned X-band high-electron mobility transistor (HEMT) voltage-controlled oscillator (VCO). The signal of the VCO is injected via a T-divider into the radiating element. To excite the first higher order mode, the designed antenna is fed asymmetrically at both ends of the microstrip line. Compared with single-terminal feeding leaky-wave antennas, this configuration offers the advantages of dual-direction and suppression of the reflected wave caused by the open end of the radiating element. The scanning angle is steered over a range of 24-46° for the right beam and 128-150° for the left beam. The effective isotropic radiated power (EIRP) is calculated to be 17.5 and 16.67 dBm at 10.4 GHz, respectively. The measured return loss S₁₁ is less than -10 dB in the range of 9-11.5 GHz. The transmission coefficient S₂₁ indicates that the power radiates into the space     

Decentralized BIST Methodology for System Level Interconnects

This paper presents an architecture for the local generation of global test vectors for interconnects in a multiple scan chain environment. A unified BIST module is inserted as the gateway for each scan chain to transform the hierarchy of backplane, boards, and scan chains into a one-dimensional array of scan chains. The BIST modules are identical for all the scan chains except for the programmable personalized memories. The personalized memory contains a scan stage type table for the test generation, response compression, and driver contention avoidance. It also contains a scan chain identification number which serves as the seed for the generation of globally distinct serial vectors. The proposed methodology achieves 100% coverage on stuck-at and short faults.     

Single-phase to three-phase power conversion interface

This study proposes a single-phase to three-phase power conversion interface which converts the power from a single-phase utility to three-phase power for a three-phase load. The proposed single-phase to three-phase power conversion interface comprises a bridge-type switch set, a set of three-phase inductors, a transformer set and a set of three-phase capacitors. A current-mode control controls the switching of bridge-type switch set, to generate a set of nonzero-sequence (NZS) currents and a set of zero-sequence (ZS) currents. The transformer set is used to decouple the NZS currents and the ZS currents. The NZS currents are used to generate a high-quality three-phase voltage that supplies power to a three-phase load. The ZS currents flow to the single-phase utility so that the utility current is sinusoidal and in phase with the utility voltage. Accordingly, only a bridge-type switch set is used in the single-phase to three-phase power conversion interface to simply the power circuit. A prototype is developed and tested to verify the performance of the proposed single-phase to three-phase power conversion interface.