Addition of garlic or onion before irradiation on lipid oxidation, volatiles and sensory characteristics of cooked ground beef

Addition of 0.5% onion was effective in reducing lipid oxidation in irradiated cooked ground beef after 7 day storage. Addition of garlic or onion greatly increased the amounts of sulfur volatiles from cooked ground beef. Irradiation and storage both changed the amounts and compositions of sulfur compounds in both garlic- and onion-added cooked ground beef significantly. Although, addition of garlic and onion produced large amounts of sulfur compounds, the intensity of irradiation odor and irradiation flavor in irradiated cooked ground beef was similar to that of the nonirradiated control. Addition of garlic (0.1%) or onion (0.5%) to ground beef produced a garlic/onion aroma and flavor after cooking, and the intensity was stronger with 0.1% garlic than 0.5% onion treatment. Considering the sensory results and the amounts of sulfur compounds produced in cooked ground beef with added garlic or onion, 0.5% of onion or less than 0.1% of garlic is recommended to mask or change irradiation off-odor and off-flavor.     

Cause of gas emission during sintering of Nd–Fe–B magnets

The degassing of an Nd_14.5Fe_76.3Ti_1.4Al_1.1B_6.7 alloy (at %) has been studied. The cause for the degassing of the Nd–Fe–B material during its sintering is shown to be hydrogen evolution. At 250–550°C, hydrogen escapes from the Nd₂Fe₁₄B phase; at higher temperatures (700–900°C), hydrogen evolution from a Nd-rich phase takes place. The cause for hydrogen evolution consists in the decomposition of the Nd(OH)₃ neodymium hydroxide during fine milling. The decomposition of hydroxide results in the formation of the Nd₂O₃ neodymium oxide, which deteriorates the magnetic isolation of Nd₂Fe₁₄B-phase grains; this leads to an abrupt increase in the irreversible magnetization losses.     

Design of Flux Observer Robust to Interior Permanent-Magnet Synchronous Motor Flux Variation

This paper presents a modified flux observer which is robust to the variation of the permanent-magnet flux linkage of an interior permanent-magnet synchronous motor (IPMSM). The IPMSM is driven by a current-regulated inverter, where the d-q axis currents are controlled by two proportional and integral controllers with feedforward cross-coupling decoupling terms. The integrator outputs of the current regulator reflecting flux errors are used to compensate the flux variation according to the operating temperature and manufacturing tolerance. The proposed flux observer shows satisfactory performance not only in maximum torque per ampere operating region but also in flux weakening region. The experimental results reveal the effectiveness of the proposed observer.     

A New Architecture for Offshore Wind Farms

Offshore wind farms using HVDC links can be positioned a large distance from shore, opening up new opportunities for wind generation. Conventional approaches using 60 Hz generators and transformers are not appropriate in such applications, as they are heavy and result in expensive and complex installation and maintenance issues. This paper proposes an alternative architecture for such wind farms, using permanent magnet generators, medium frequency transformers and simple power converters to realize a compact and light system. It is possible that in the long term, the proposed approach may prove attractive for land-based wind farms as well.     

New approach for the low-speed operation of PMSM drives withoutrotational position sensors

A new approach to the position sensor elimination of permanent magnet synchronous machine (PMSM) drives for low-speed operation is presented in this paper. Using the position sensing characteristics of the PMSM itself, the actual rotor position, as well as the machine speed, can be obtained even in the transient state. Since the essential back-EMF information is obtained from direct measurement during a special test cycle called MCDI, the operating speed range of the sensorless drives can be extended to 10 RPM. Moreover, the chronic starting problem of PMSM drives can be simply settled by the proposed algorithm. In order to verify the feasibility of the proposed scheme, experimental results in the low-speed range of about 10~100 RPM are also presented     

Microprocessor-Based Optimal-Efficiency Drive of an Induction Motor

A method for improving the efficiency of a slightly loaded induction motor is suggested. It is based upon the optimal-efficiency slip tracking by adjusting the voltage to frequency ratio (V/f). It has adopted the converter-inverter fed induction motor drive system. All the control loops are implemented by the Z-80 microprocessor. By this method, 10 percent or more improvement is obtained at a quarter of the full load.     

A novel dynamic overmodulation strategy for fast torque control of high-saliency-ratio AC motor

This paper describes the dynamic overmodulation strategies for fast torque control of the high-saliency-ratio ac motor. For the high-saliency-ratio ac motor, the dynamic control of both d- and q-axes currents is required for fast torque control with optimal efficiency. However, in transient operation, the d- and q-axes current regulators are easily saturated even at low speed because the stator inductance is designed large enough to generate the desired reluctance torque. With the conventional overmodulation strategies, the current regulation performance degrades severely compared to a nonsalient motor. In this paper, the drawbacks of the conventional overmodulation strategies are investigated and a dynamic overmodulation strategy is proposed to improve the current response to fast transients. For the effective implementation of the strategy, a practical algorithm is also presented. The performance of the proposed strategy is confirmed by computer simulation and experiment with a 3.75-kW axially laminated synchronous reluctance motor and an interior permanent-magnet synchronous motor for 42-V integrated starter-generator applications.     

CNC Module for Turning: A New CAM Application

The integrated CAM application for the KOMPAS-3D environment known as CNC Module for Turning is considered. This application permits automated development of control programs for numerically controlled lathes. The user may readily adapt the CAM application for specific production conditions and machine tools, thanks to features such as the following: representation of the cutting tools by means of parametric 3D models, the possibility of including fixed CNC cycles in the control programs, and the use of the Python language for programming of the postprocessors.     

The effects of the selectivity of the toluene/ethanol mixture on the micellar and the ordered structures of an asymmetric poly(styrene-b-4-vinylpyridine)

The effects of the solvent selectivity of toluene/ethanol mixtures on the micellar and ordered structures of an asymmetric diblock copolymer of PS(19.6 K)-b-P4VP(5.1 K) in the dilute (1 wt%) and semi-dilute (8 wt%) solutions, as well as in the gel and solid films, were studied using small angle X-ray scattering (SAXS), generalized indirect Fourier transform (GIFT), and transmission electron microscopy (TEM) methods. The solvent selectivity was controlled by ? (weight percentage of ethanol in toluene/ethanol mixture). Individual micelles, space-filled micellar structure (without three-dimensional order), and three-dimensionally ordered gel and solid structures were observed from the 1 and 8 wt% solutions, the gel, and the solid film, respectively. In the 1 wt% solution, the individual micellar structures were strongly dependent on ?; the spherical micelles with P4VP core at ? = 0, the unimer state at 10 ≤ ? ≤ 50, the spherical micelles with PS core at ? = 60, the cylindrical micelles with PS core at ? = 70 and 80, and precipitation at ? = 90 and 100 were observed. The 8 wt% solution was close to overlap concentration with the unimer state in the regions of 20 ≤ ? ≤ 40. In the gel, the ordered structure was observed in the sequence of bcc, hexagonal, gyroid, lamellar, reverse hexagonal and random as ? increased, and could be explained by the change of the relative volume fraction of each block as ? changed, similar to the phase sequence in the phase diagram of the diblock copolymer. The solid films showed the various kinetically frozen ordered microstructures such as randomly packed sphere, hexagonal, gyroid, hexagonally perforated lamella, reversed hexagonal, and randomly packed cylinder, which were controlled by the solvent quality in the gel before solidification. We believe that these results can be applied to photonic crystals, self-assembled nano-patterning, and functional nanoparticles in which the structural control is most important.     

A new direct-synthesis tuning method for pi-controllers

A new efficient tuning method for proportional-integral (PI) controllers is proposed using overdamped closed-loop dynamics of the system. In line with other direct-synthesis and IMC methods, this new approach uses the desired closed-loop response to satisfy usual control and tuning objectives, but unlike the most other tuning methods hitherto-reported for PID controllers, it does not require that a process model be identified. Yet this new direct-synthesis (NDS) method is capable of making the controller perform the dual control functions of both good set-point tracking and disturbance rejection. Furthermore, it turns out that the new tuning method works equally well for difficult cases like large time delay and nonminimum phase processes. Finally, it can be said that this NDS method can be easily implemented and understood by the plant operating personnel because it has been developed emphasizing its on-site utility.