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Flavors represent a small but significant segment of food industry. Taro gives a pleasant nut-like odor when cooked. Taro flavor can be used in many products, so developing a taro flavor is of interests. This paper concentrates on preparation and simulation of taro flavor according to the notes of taro, which are distinct flavors or odor characteristics. The results show that the notes of taro flavor can be classified as caramellic note, roast note, milky note, beany note, green note, aldehydic note, sweet note, nutty note, vegetative note, and fruity note. According to the notes of cooked taro odor and the raw materials selected, a typical taro flavor formula is given. The taro flavor blended is pleasant, harmonious, and has characteristics of the odor of cooked natural taro.

Biomass is recognized as an important solution to energy and the environmental problems related to fossil fuel usage. The rational utilization of biomass waste is important not only for the prevention of environmental issues, but also for the effective utilization of natural resources. Pyrolysis and hyrolysis in subcritical water are promising processes for biomass waste conversion. This paper deals with hydrolysis and pyrolysis of peanut shells. Hydrolysis and pyrolysis kinetics of peanut shell wastes were investigated for the in-depth exploration of process mechanisms and for the control of the reactions. Hydrolysis kinetics was conducted in a temperature range of 180–240 °C. A simplified kinetic model to describe the hydrolysis of peanut shells was proposed. Hydrolysis activation energy as well as the pre-exponential factor was determined according to the model. The target products of peanut shell hydrolysis, reducing sugars, can reach up to 40.5 % (maximum yield) at 220 °C and 180 s. Pyrolysis characteristics were investigated. The results showed that three stages appeared in this thermal degradation process. Kinetic parameters in terms of apparent pyrolysis activation energy and pre-exponential factor were obtained by the Coats–Redfern method.

This paper describes a new approach to the analysis of switched mode power converters utilizing coupled inductors and presents a novel canonical circuit model for N-winding coupled inductors. Waveform and ripple of the winding current in a coupled inductor converter can be easily determined using the developed model similar to those obtained in an uncoupled inductor converter. Influence of coupling coefficient on converter steady state and transient performances is readily predicted by the proposed model and a comparison of coupled and uncoupled inductor converters is provided. It is found that coupling among windings effectively alters the phase node voltage waveforms driving the coupled inductors. Through coupling, a converter is capable of responding faster to load transient depending on the coupling coefficient and control mechanism, and this dependency is analytically revealed in the paper. Some design constraints regarding coupling coefficient are also discussed for two-winding and multi-winding coupled inductors in power converter applications. Finally, a two-phase buck regulator is experimentally tested to verify the proposed model.

The recovery of waste substances is important not only for the prevention of environmental issues, but also for the rational utilization of natural resources. Hydrolysis reaction in sub-critical water is a promising method for the treatment of organic wastes and has been attracting worldwide attention. In this paper, sub-critical water hydrolysis was employed as a method for producing amino acids, reducing sugars, bio-oil and gas fuels from biomass wastes. The current statuses of these useful chemicals production from biomass wastes by hydrolysis in sub-critical water were reviewed. The review indicates that sub-critical water hydrolysis can be an efficient process for recovering useful chemicals from biomass wastes. This method is renewable, sustainable, efficient, and safe for the environment.

A new single-stage, single-switch power factor correction converter with output electrical isolation is proposed in this paper. The topology of this converter is derived by combining a boost circuit and a forward circuit in one power stage. To improve the performance of the AC-DC converter (i.e., good power factor correction, low total harmonic distortion (THD) and low DC bus voltage), two bulk storage capacitors are adopted. Its excellent line regulation capability makes the converter suitable for universal input application. Due to its simplified power stage and control circuit, this converter presents a better efficiency, lower cost and higher reliability. Detailed steady state analysis and design procedure are presented. To verify the performance of the proposed converter, a design example along with P-simulation program with integrated circuit emphasis (PSPICE) simulation and experimental implementation are given. The measured power factor and efficiency are 99% and 87% at low line (i.e. 110 VAC) operation, and 95% and 81% at high line (i.e. 220 VAC) operation, respectively.

It is shown that an incorrect parameter limit in the existing Pspice pulsewidth modulated (PWM) switch model has been detected. The main objective of this work is to alert users of such models to a potential source of simulation error under certain parameter specifications as shown here. Simulation of the boost converter operating in discontinuous conduction mode (DCM) based on the incorrect model results in either convergence problems or wrong results. Correction of the model is provided and its validity is verified using a specific converter example. The results illustrate how the old and corrected models produce different results when the boost converter is subjected to some transients under sudden load variations.

By performing a detailed analysis of switching-mode power supplies based on swithed-capacitor circuits, their fundamental steady-state characteristics are found. A few basic step-down and step-up converters are considered. No approximations, such a averaging techniques are required. The on-resistances of the transistors, forward voltages of the diodes and equivalent-series resistances of capacitors are taken into account. Design-oriented formulas of the DC voltage ratio, trade-offs allowing for the best possible efficiency, the smallest possible ripple and the best possible line and load regulation give the design values of the number of capacitors in the switched-capacitor circuit, of their capacitances and of the switching frequency.

A switched-capacitor-based (SC) step-up DC converter is proposed. It contains no inductors and transformers, thus it can be realized in small size, exhibiting low weight and high power density. Two switched-capacitor circuits, operating in antiphase in each half-cycle, are used to control the energy flow from an unregulated voltage source to a regulated output. The capacitors are charged and discharged according to a designed sequence. To enhance the line and load regulation capability, in each half-cycle, each charging interval is split into two subintervals, which are followed by noncharging subintervals whose duration is dictated by the pulsewidth modulation (PWM) feedback circuit. The new converter is advantageous for applications in which significant line drops are likely to occur.

Fragrance and flavor play an important role in many fields. Fragrance and flavor technology is a core course for training the students whose major is light chemical engineering. This paper deals with the applications of computer in this course. The applications of Internet, flavor and fragrance computer software, electronic nose and electronic tongue in Flavor and Fragrance Technology were discussed. The Internet is widely used to gather information about flavors and fragrances. Flavor and fragrance creation computer software became an important tool for perfume development and expanding knowledge of perfumery raw materials. Electronic nose and electronic tongue are two devices controlled by computer and intended to detect odors and tastes respectively. They can avoid a number of drawbacks caused by human fatigue or stress.

In this part of the sequel on the modeling and analysis of coupled inductors and coupled inductor based multiphase switching converters, the recently developed symmetrical coupled inductor model is first extended to include the inductor winding dc resistance (DCR). The extended model is then used to analyze the influence of the coupling on the DCR based current sensing schemes popularly used in multi-phase switching regulators. It is found that the time-constant matching condition in coupled inductor converters needs to be modified to include the coupling coefficient. The proposed model is also used to derive the small-signal control-to-output transfer function of the converters incorporating coupled inductors, with which the effect of coupling on the dynamic behaviors of the converter power stage, such as resonant frequency and damping factor, can be easily evaluated.

A comprehensive and accurate steady-state analysis of a step-up DC-DC switched-capacitor power converter is performed. No approximations, such as average techniques, are invoked. Parasitic elements such as diode forward voltages, on-resistances of transistors and equivalent-series resistances of capacitors are included into the model. The converter performance functions, i.e. DC voltage ratio, efficiency, output voltage ripple, are expressed in terms of the number of switched-capacitor stages, number of capacitors per stage, values of the capacitors and parasitic elements, switching frequency and load. Design criteria aiming at high efficiency, low ripple and achievable output voltage are formulated. Trade-offs between the efficiency requirement and good regulation capability are discussed.

The conventional voltage source inverter for motor drive encountered severe problems such as high EMI, wide range of harmonics, heavy acoustic noise and low efficiency. Resonant DC-link inverter technique becomes dominate in solving the above problems due to its simplicity in both power stage topology and control strategy. In this paper, operation principle of resonant DC-link inverter is analyzed. A design procedure of this type inverter for high power application (200 HP) is presented. PSPICE simulation on the designed resonant DC-link inverter has been conducted to verify its availability for high power application. The improvements in motor drive by using resonant DC-link inverter is shown by comparing the PSPICE simulation results of conventional hard switching inverter.

In this paper, a non-ideal PWM switch model considering conduction losses is developed. This issue was considered in the past only with the assumption that the inductor current ripple is negligible compared with its average value. Derivation of the new model is based on the energy loss invariant principle. The resulting model can be applied to simulating large inductor current ripple conditions. Accuracy of the proposed model is verified through Pspice simulation using the buck and boost converters.

A large signal simulation for two parallel converters in a distributed power supply system is presented in this paper. The distributed system is composed of switched-mode power factor correction (PFC) converters utilizing a central limit control technique. This technique allows one voltage loop compensator to be shared by all the PFC converters. Design of such a compensator is discussed and the system performances with regard to unequal cable resistances and load changes are reported. The resulting system achieves a power factor of about 0.98 and provides an excellent current sharing between the two converter modules.

A single-switch, one-stage power factor correction converter with output electrical isolation is proposed. To relieve the voltage spike caused by the leakage inductance of the power transformer, two bulk storage capacitors are used. The proposed converter has both a good power factor correction and excellent line and load regulation capabilities with an efficiency of 87%.

High DC bus voltage stress is an important issue for the single stage PFC converters in practical application. This paper analyzes the inherent reason of the high bus voltage stress of single-stage power-factor-correction (PFC) AC/DC converters. Four possible resolving schemes are analyzed and discussed, and some of practical implementation circuits topologies are also given. Theoretical analysis and simulation results show that the both series-charging, parallel-discharging capacitors (SCPDC) scheme and bus-voltage-feedback (BVF) method are deemed to be more viable than the other two methods.