The interplay between A-site randomness and magnetic phase transition in half-doped manganite Pr0.5Ba0.5MnO3 (PBMO) was extensively investigated. The H/M versus M-2 isotherms show that the A-site ordered PBMO undergoes a second-order magnetic phase transition from paramagnetism to ferromagnetism, whereas the A-site disordered PBMO exhibits a fluctuation-driven first-order transition arising from a competing order phase possibly existing in the paramagnetic state. A step-like transition in magnetization and resistivity with a sharp width of Delta H/H similar to 10(-3) was only observed in the A-site partially ordered PBMO at 2 K, indicating that the metamagnetic transition is associated with a competition between randomly distributed short-range ferromagnetic and antiferromagnetic phases. These findings provide evidence that the A-site randomness not only suppresses A-type antiferromagnetism also moderately weakens long-range ferromagnetism in the A-site ordered PBMO.

The battery charging performance in a stand-alone solar PV system affects the PV system efficiency and the load operating time. The New Energy Center of National Taiwan University has been devoted to the development of a PWM charging technique to continue charging the lead-acid battery after the overcharge point to increase the battery storage capacity by more than 10%. The present study intends to use the super-capacitor to further increase the charge capacity before the overcharge point of the battery. The super-capacitor is connected in parallel to the lead-acid battery. This will reduce the overall charging impedance during the charge and increase the charging current, especially in sunny weather. A system dynamics model of the lead-acid battery and super-capacitor was derived and the control system simulation was carried out to predict the charging performance for various weathers. It shows that the overall battery impedance decreases and charging power increases with increasing solar radiation. An outdoor comparative test for two identical PV systems with and without supercapacitor was carried out. The use of super-capacitor is shown to be able to increase the lead-acid charging capacity by more than 25% at sunny weather and 10% in cloudy weather.

The present study developed a high-performance solar PV power technology for the LED lighting of a solar home system. The nMPPO (near-Maximum-Power-Point-Operation) design is employed in system design to eliminate MPPT. A feedback control system using pulse width modulation (PWM) technique was developed for battery charging control which can increase the charging capacity by 78%. For high-efficiency lighting, the LED is directly driven by battery using a PWM discharge control to eliminate a DC/DC converter. Two solar-powered LED lighting systems (50W and 100W LED) were built. The long-term outdoor tests have shown that the loss of load probability for full-night lighting requirement is zero for 50W LED and 3.6% for 100W LED.

The lead-acid battery which is widely used in stand-alone solar system is easily damaged by a poor charging control which causes overcharging. The battery charging control is thus usually designed to stop charging after the overcharge point. This will reduce the storage energy capacity and reduce the service time in electricity supply. The design of charging control system however requires a good understanding of the system dynamic behaviour of the battery first. In the present study, a first-order system dynamics model of lead-acid battery at different operating points near the overcharge voltage was derived experimentally, from which a charging control system based on PI algorithm was developed using PWM charging technique.The feedback control system for battery charging after the overcharge point (14 V) was designed to compromise between the set-point response and the disturbance rejection. The experimental results show that the control system can suppress the battery voltage overshoot within 0.1 V when the solar irradiation is suddenly changed from 337 to 843 W/m(2). A long-term outdoor test for a solar LED lighting system shows that the battery voltage never exceeded 14.1 V for the set point 14 V and the control system can prevent the battery from overcharging. The test result also indicates that the control system is able to increase the charged energy by 78%, as compared to the case that the charging stops after the overcharge point (14 V). (C) 2010 Elsevier Ltd. All rights reserved.

The solar-powered LED lighting system has been commercialized for a long time. The system usually consists of a DC to DC converter in order to convert the battery voltage into a fixed voltage or current for the LED lighting luminaire. This will cause energy loss and system reliability due to the failure of DC/DC converter. In the present study, we develop a special technique to drive the LED luminaire directly from battery utilizing PWM technique in order to remove the DC/DC converter. However, instantaneous current overdriven can occur easily due to the variation of battery voltage with the state-of-charge of battery.In the present study, we setup a thermal chamber with temperature variation to within 40 +/- 30 degrees C. A LED luminaire was specially designed for the LED reliability test with four different circuits with each circuit connecting three LED lamps serially. A driver is designed to provide 4 kinds of power inputs to LED: (a) 350mA constant current, (b) 700mA, 100Hz, duty cycle=50%, (c)700mA, 10K Hz duty cycle=50% and (d) 1050mA, 100Hz, duty cycle=33%. The tests were performed simultaneously to compare light decay between normal drive condition (a) and other PWM driving conditions (b, c, d). The accumulated total test time so far is more then 7,032 hours and has shown no significant light decay in 4 different loops. This reveals that the PWM technique directly driven by battery is feasible and is able to reduce energy loss of DC to DC converter in the solar lighting system.

SM1-PD-16 Introduction: Among men heavily exposed to polychlorinated biphenyls (PCBs) and polychlorinated dibenzofurans (PCDFs), increased percent of oligospermia, reduced sperm capability of penetrating oocytes, and reduced percent of male offspring were reported by our study group. The mechanism of such effects is unknown. We test the hypothesis that effects on gender ratio and sperm functioning is related to sperm chromosomal aneuploidy. Methods: During 1978 to 1979, over 2000 Taiwanese ingested rice oil contaminated with PCBs and its pyrolytic product, mainly PCDFs. This episode was referred to as “Yucheng” (“oil-disease” in Chinese) exposure. In 1999 to 2000, exposed men and their controls 37 to 50 years of age were recruited for physical examination followed by semen analysis. Semen samples were studied for chromosomal aneuploidy by fluorescent in situ hybridization with an established procedure in our laboratory. Hybridization procedures were done using centromere-specific probes directly labeled by fluorescence dyes (Vysis, Downers Grove, IL), including CEP X (SpectrumAqua), CEP Y (SpectrumOrange), and CEP 8 (SpectrumGreen). Each cell was scored for the number of fluorescent spots. Results: A total of 50 men exposed to PCBs/PCDFs and 34 unexposed matched controls volunteered to participate in the study. The age, body height and weight, percent of smokers, and period of abstinence from ejaculation were not different between exposed and control men. Percents of sperm with normal numbers of chromosomes X,Y, and 8 were not different between the 2 groups. Percents of sperm with aneuploidy of sex chromosomes or chromosome 8, and those with diploidy, were not different between Yucheng and control men. Ratios of normal X/normal Y sperm were not different between the exposed and control group. However, among Yucheng men, 4 (8%) had normal X/normal Y sperm ratio of >1.4; and among controls, none had such elevated X/Y ratio (not statistically significant by Fisher's exact test). Discussion and Conclusions: Chromosomal aneuploidy, diploidy, and X/Y sperm ratio were not increased in men highly exposed to PCBs/PCDFs despite reduced sperm capability of oocyte penetration, mildly increased abnormal morphology, and changed gender ratio in exposed men. The mechanisms of the latter remained to be determined.

The structural and magneto-transport properties of electron-doped manganites (La1−xPrx)0.85Zr0.15MnO3 (Pr-doped LZMO) with x=0, 0.05, 0.10, 0.15, and 0.20 have been investigated. X-ray diffraction (XRD) patterns show that the Pr-doped LZMO has rhombohedral lattice structure with R3¯C space group. The Mn–O–Mn bond angle of the system refined by Rietveld technique decreases with increasing Pr content ranging from 165.38° for x=0 to 163.64° for x=0.20. A significant distortion of the MnO6 octahedra caused by the distinctively small Mn–O–Mn bond angle weakens the strength of Mn2+–O–Mn3+ double exchange (DE) interaction. The Curie temperature TC increases with increasing average A-site ionic radius, 〈rA〉, and the magnetoresistance (MR) ratio decreases with increasing 〈rA〉, strongly suggesting that the DE mechanism plays an important role in the charge transport property of the Pr-doped LZMO.

This study presents a hybrid X-ray microscope that magnifies an X-ray image using a group of asymmetrically cut crystals and an X-ray phase contrast imaging system. An asymmetrically cut crystal is inserted between the sample and a CCD-fluorescence assembly. The experimental results demonstrate that the phase contrast image is preserved. This system can be improved using a better diffraction crystal.

ISEE-131 Introduction: Among men heavily exposed to polychlorinated biphenyls (PCBs) and polychlorinated dibenzofurans (PCDFs), increased percentage of oligospermia, reduced sperm capability of penetrating oocytes, and reduced percentage of male offspring were reported by our study group. The mechanism of such effects is unknown. Aim: We test the hypothesis that effects on gender ratio and sperm functioning is related to sperm chromosomal aneuploidy. Methods: During 1978-79, over 2,000 Taiwanese ingested rice oil contaminated with PCBs and its pyrolytic products, mainly PCDFs. This episode was referred to as “Yucheng” (“oil-disease” in Chinese) exposure. In 1999-2000, exposed men and their controls, aged 37-50 years, were recruited for physical examination followed by semen analysis. Semen samples were studied for chromosomal aneuploidy by fluorescent in situ hybridization (FISH). After semen sample preparation, hybridization procedures were done using centromere-specific probes directly labeled by fluorescence dyes (Vysis, Downers Grove, IL), including CEP X (SpectrumAqua), CEP Y (SpectrumOrange) and CEP 8 (SpectrumGreen). Each cell was scored for the number of fluorescent spots. Results: A total of 50 men exposed to PCBs/PCDFs and 34 unexposed matched controls volunteered to participate in the study. The age, body height and weight, percent of smokers, and period of abstinence from ejaculation were not different between exposed and control subjects. Percentage of sperm with normal numbers of chromosomes X,Y, and 8 were not different between the two groups. Percentage of sperm with aneuploidy of sex chromosomes or chromosome 8, and those with diploidy were not different between Yucheng and control subjects. Ratios of normal X/normal Y sperm were not different between the exposed and control groups. However, among Yucheng men, 4 (8%) had normal X/normal Y sperm ratio of >1.4, and among controls, none had such elevated X/Y ratio (not statistically significant by Fisher’s exact test). Discussion: Chromosomal aneuploidy was not elevated in PCB/PCDF-exposed men. Offspring gender-ratio (male:female) was reduced for approximately 10 years after Yucheng men were exposed to PCB/PCDF-contaminated rice oil. In this study, disproportional reduction of normal Y sperm was not seen in Yucheng subjects. However, among Yucheng men, 4 (8%) had normal X/normal Y sperm ratio of >1.4, and among controls, none had such elevated X/Y ratio (not statistically significant by Fisher’s exact test). Whether individuals had different susceptibility, among exposed people, remains to be determined. Conclusion: Chromosomal aneuploidy, diploidy, and X/Y sperm ratio were not increased in men highly exposed to PCBs/PCDFs despite reduced sperm capability of oocyte penetration, mildly increased abnormal morphology, and changed gender ratio in exposed men. The mechanisms of the latter remain to be determined.

Mn L-3,L-2-, K-, O K- and Pr M-5,M-4-edge x-ray absorption near-edge structure (XANES) spectra of (La1-xPrx)(0.85)Zr0.15MnO3 (LPZMO) with x = 0, 0.05, 0.1, 0.15 and 0.2 were measured to study the electronic structure and the effect of Pr substitution. An analysis of Mn L-3,L-2- and K-edge spectra indicates that LPZMO is an electron-doped system. Pr substitution is found to increase the average effective charge of Mn ions and to induce an additional unoccupied majority spin (up arrow spin) eg subband in the Mn L-3.2-edge XANES spectrum. Mn L-3.2-, O K- and Pr M-5,M-4-edge XANES results demonstrate that the substitution of La ions by smaller Pr ions changes O 2p-Mn 3d and O 2p-Pr 4f hybridized states. Extended x-ray absorption fine structure (EXAFS) analysis at the Mn K edge reveals clear changes in local atomic structure around Mn ions due to the Pr substitution. XANES and EXAFS analyses show a small distortion in the MnO6 octahedron or a disorder in the lattice, which may be due to localization of charge carriers and/or the increased effective positive charge of Mn ions.

This paper presents a scale method for developing high dimensional scale functions to blend implicitly defined objects. Scale functions are differentiable on the entire domain except the origin, provide blending range control, and behave like Min/Max operators everywhere, so even a successive composition of blending operations containing overlapped blending regions can be generated smoothly. Because the scale method is a generalized method, implicit or parametric curves, such as cubic Bezier curves, rational conic curves, and implicit conics and hyper-ellipsoids, can be used to develop scale functions. As a result, it can enhance the flexibility of generating the implicitly blending surfaces in Ricci's constructive geometry, soft objects modeling, and implicit sweep objects.

This paper proposes new field functions that have adjustable inner radius and outer radius of influence. Incorporatingthe proposed field functions with soft object modeling, soft blending, Ricci's super‐ellipsoid blends, Perlin'sset operations, and R‐functions, etc. can have blending range controls by adjusting the inner and the outer radiiof influence of given field functions. As a result, the sizes of the resulting blending surfaces on soft objects willnot be restricted by the sizes of the blended primitive soft objects and can be enlarged and shrunk freely withoutdeforming the overall shapes of blended primitive soft objects. In addition, a small soft object can have a largeblending region, and a large one can have a small blending region

Experimental results obtained in room temperature laboratory leaching studies of lowgrade chrysocolla are interpreted by a kinetic equation of the form 1−(1−R)1/3=(1/αKr c) ln (αkKC 0t+1) derived on the basis of a special form of the shrinking-core model and assuming chemical-reaction control. The experimental program encompasses a large range of particle sizes and reaction times and significantly extends previous experimental data on similar ore systems. The kinetic model, shown to be consistent with the experimental data, assumes the ore-particle structure to be characterized by pores and channelized regions which extend from the outer surface through a reacted zone into the unreacted core. Scanning electron microscope observations of unreacted particle surfaces as well as reacted particle surface structures lend support to this concept of leaching. The reaction rate is observed to vary inversely with initial mean particle radius, and diffusion in any form appears to be negligible by comparison with surface reaction phenomena.