THE ANTIOXIDATIVE POTENTIAL OF LYOPHILIZED CITRUS PEEL EXTRACT IN DIFFERENT MEAT MODEL SYSTEMS DURING STORAGE AT 20C

Antioxidative potential of lyophilized citrus (Citrus unshiu) peel extract in raw and cooked meat systems was investigated. Beef pork, chicken, and salmon patties were prepared without (control), with lyophilized citrus peel extract (0.1%, NICP), and with 20 kGy-irradiated, lyophilized citrus peel extract (0.1%, ICP). TBARS value showed that the addition of lyophilized citrus peel (NICP or ICP) inhibited the development of lipid oxidation of raw and cooked meat patties during storage for 8 days at 20C (P<0.05) except for raw chicken patty. Hunter color a*-values of the cooked meat patties treated with NICP or ICP were higher than those of the control (P<0.05). Irradiation of citrus peel extract did not show any notable changes in its antioxidant effect in the meat systems. Thus, the lyophilized citrus extract could be used as one of the natural antioxidants with the potential of cost-effectiveness and is environmentally friendly.     

Characterizing the formation and growth of intermetallic compound in the solder joint

A solder/intermetallic layers/copper joint assembly was prepared by the dipping process and then aged thermally for an accelerating aging test. The phase transformation of the assembly was compared to the phase diagram of binary alloy, Cu–Sn, and it showed an agreement with the resultant intermetallic phases formed between the pure tin and pure copper. Two theoretical models proposed by Gösele and Shatynski were developed and then employed to characterize the assembly. The Gosele's model was used to predict whether the intermetallic layers grew or shrank during aging, while the Shatynski's model was employed to estimate the related reactive thicknesses and hence the ratios of the interdiffusivities in the joint assembly. After a series of calculations, the Gösele's model predicted that Cu6Sn5 and Cu3Sn intermetallic layers became thicker; the orders of the intermetallic interdiffusivities were also proven to approach theoretical values from the Shatynski's model.     

ON-LINE SIGNATURE VERIFICATION BASED ON LOGARITHMIC SPECTRUM

In this paper, an on-line signature verification scheme based on similarity measurement of logarithmic spectrum is proposed. The principal components of the logarithmic spectrum of each signature are extracted. We then compute the similarity of logarithmic spectrum between input signature and the reference template. By comparing the similarity of logarithmic spectrum with the verification threshold, we can determine the authenticity of the input signature. Based on the experimentation, the rates of false rejection errors and false acceptance errors are as low as 1.4 and 2.8%, respectively. This demonstrates the effectiveness of the proposed scheme.     

Improvement in Background Error Covariances Using Ensemble Forecasts for Assimilation of High-Resolution Satellite Data

Satellite data obtained over synoptic data-sparse regions such as an ocean contribute toward improving the quality of the initial state of limited-area models.Background error covariances are crucial to the proper distribution of satellite-observed information in variational data assimilation.In the NMC (National Meteorological Center) method,background error covariances are underestimated over data-sparse regions such as an ocean because of small differences between different forecast times.Thus,it is necessary to reconstruct and tune the background error covariances so as to maximize the usefulness of the satellite data for the initial state of limited-area models,especially over an ocean where there is a lack of conventional data.In this study,we attempted to estimate background error covariances so as to provide adequate error statistics for data-sparse regions by using ensemble forecasts of optimal perturbations using bred vectors.The background error covariances estimated by the ensemble method reduced the overestimation of error amplitude obtained by the NMC method.By employing an appropriate horizontal length scale to exclude spurious correlations,the ensemble method produced better results than the NMC method in the assimilation of retrieved satellite data.Because the ensemble method distributes observed information over a limited local area,it would be more useful in the analysis of high-resolution satellite data.Accordingly,the performance of forecast models can be improved over the area where the satellite data are assimilated.     

An Evaluation of the Machinability of Nitinol SMA Using Combined Process of EP and MR Polishing

Nitinol,a shape memory alloy(SMA),is manufactured from titanium and nickel.It is employed in various fields for use in devices such as micro sensors,ultra-precision devices and satellite wings.It is highly recommended as a material in medical stents for insertion into the body because it has excellent organic compatibility.However,because they are intended to be inserted into the human body,products such as medical stents require a high-quality surface.Because nitinol has more of the characteristics of titanium than of nickel,one of its drawbacks is that heat generated in nitinol during machining is not discharged smoothly,leading to areas of inner stress which occur when traditional machining methods are used.To overcome this difficulty,various non-traditional machining methods,including non-contact machining,have been investigated for use with nitinol.This study is focused on the application of an effective fabrication method that combines electrolytic polishing(EP)and MR polishing to improve the surface integrity of nitinol through a series of experiments.Surface roughness variations of the polished nitinol were investigated by changing the imposed polishing conditions of EP and MR polishing,respectively.Finally,the variations in the surface roughness were observed with polished previously performed via the EP process.     

ANALYSES OF THE SIMULTANEOUS ABSORPTION OF TWO GASES WITH EXOTHERMIC REACTION

This study examines the effects of various parameters on the nonisothermal gas absorption. A pair of coupled irreversible and reversible (1, ) order exothermic chemical reactions are considered in this research. The film model is employed to describe the heat and mass transfer. The interfacial temperature rise and the enhancement factors are determined nonlinearly by Muller's method. The nonisothermal effects of gas absorption are presented as functions of the dimensionless group M^½ at given thermophysical properties and kinetic parameters. The analyses provide useful information for nonisothermal reactor design and modeling.     

Through‐wall welding residual stress profiles for dissimilar metal nozzle butt welds in pressurized water reactors

This paper provides approximate expressions for through‐wall welding residual stresses in dissimilar metal nozzle butt welds of pressurized water reactors. An idealized shape of nozzle is proposed, based on which systematic elastic–plastic thermo‐mechanical finite element analyses are conducted by varying the thickness and radius of the nozzle and the length of the safe‐end. Based on the results, a through‐wall welding residual stress profile for dissimilar metal nozzle butt welds is proposed by modifying the existing welding residual stress profile for austenitic pipe butt welds in the R6 procedure.     

Numerical simulation for thermal response test performance in closed-loop vertical ground heat exchanger

In this study, a series of numerical analyses was performed in order to evaluate the performance of full-scale closed-loop vertical ground heat exchangers constructed in Wonju, South Korea. The circulating HDPE pipe, borehole and surrounding ground formation were modeled using FLUENT, a finite-volume method (FVM) program, for analyzing the heat transfer process of the ground heat exchanger system. Two user-defined functions (UDFs) accounting for the difference in the temperature of the circulating inflow an...