Fluorescence characteristics of wholesome and unwholesome chicken carcasses

Each chicken carcass intended for U.S. consumers is mandated to be inspected by Food Safety and Inspection Service (FSIS) inspectors for its wholesomeness at the processing plants. Fluorescence responses of wholesome and unwholesome chicken carcasses were characterized and further evaluated for potential on-line applications for detection and classification of wholesome and unwholesome chicken carcasses. For this study, unwholesome chicken carcasses included cadaver and those with disease conditions such as airsacculitis and septicemia. Fluorescence characteristics from the epidermal layers in the breast areas of chicken carcasses were dynamic in nature. Emission peaks and ridges (maxima) were observed at 386, 444, 472, 512, and 554 nm and valleys (minima) were observed at 410, 460, 484, and 538 nm. One of the major factors affecting the line shapes of fluorescence responses from chicken carcass skin layers was absorption by hemoglobin. With the use of the normalized ratio spectra (NRS) approach, oxyhemoglobin was shown to be a major constituent in chicken carcasses affecting the fluorescence emission line shapes. Subtle line shape changes in the NRS also provided a qualitative means by which to assess the minute differences in oxy- and deoxyhemoglobin compositions perturbed by poultry diseases such as septicemia and airsacculitis. With the use of simple fluorescence band ratios as a multivariate model, wholesome and unwholesome chicken carcasses were correctly classified with 97.1% and 94.8% accuracies, respectively. On-line implementation of fluorescence techniques for the assessment of chicken carcass wholesomeness appears promising.     

Synthesis of silver nanoparticles using the polyol process and the influence of precursor injection

Spherical silver nanoparticles with various sizes and standard deviations were synthesized by the polyol process. Two different synthesis methods were compared in order to investigate the influence of reaction parameters on the resulting particle size and its distribution. In the precursor heating method, wherein a solution containing silver nitrate was heated to the reaction temperature, the ramping rate was determined to be a critical parameter affecting the particle size. In contrast, in the precursor injection method, in which a silver nitrate aqueous solution was injected into hot ethylene glycol, because of rapid nucleation, the injection rate and the reaction temperature were important factors in terms of reducing the particle size and attaining monodispersity. Silver nanoparticles with a size of 17 ± 2?nm were obtained at an injection rate of 2.5?ml?s(-1) and a reaction temperature of 100?°C.     

Effect of calcium phosphate glass on bone formation in calvarial defects of Sprague-Dawley rats

The purpose of this study was to investigate the bone regenerative effect of calcium phosphate glass in vivo. We prepared two different sizes of calcium phosphate glass powder using the system CaO-CaF₂-P₂O₅-MgO-ZnO; the particle size of the powders were 400 μm and 40 μm. 8 mm calvarial critical-sized defects were created in 60 male Sprague-Dawley rats. The animals were divided into 3 groups of 20 animals each. Each defect was filled with a constant weight of 0.5 g calcium phosphate glass powder mixed with saline. As controls, the defect was left empty. The rats were sacrificed 2 or 8 weeks after postsurgery, and the results were evaluated using radiodensitometric and histological studies; they were also examined histomorphometrically. When the bigger powders with 400 μm particle were grafted, the defects were nearly completely filled with new-formed bone in a clean healing condition after 8 week. When smaller powders with 40 μm particle were transplanted, new bone formation was even lower than the control group due to a lot of inflammatory cell infiltration. It was concluded that the prepared calcium phosphate glass enhanced the new bone formation in the calvarial defect of Sprague-Dawley rats and it is expected to be a good potential materials for hard tissue regeneration. The particle size of the calcium phosphate was crucial; 400 μm particles promoted new bone formation, while 40 μm particles inhibited it because of severe inflammation.     

A study on electric conductivity of phosphoric acid supported on nano-pore rice husk silica in H2/Pt/H3PO4 / RHS/Pt/O2 fuel cells

PEMFC (Polymer Electrolyte Membrane Fuel Cell) is widely considered as an energy conversion system from the chemical energy of hydrogen to electric energy. But, hydrogen fuel obtained from hydrocarbons has trace amount of carbon monoxide which is a potential poison for platinum electrode at the cell operating temperature approximately 100 degrees C and it becomes a huddle for the general usage of PEMFC. On the other hand PAFC (Phosphoric Acid Fuel Cell) operates at a higher temperature and the platinum electrode oxidizes carbon monoxide poison while there is a leakage problem of the liquid phase. To combine the advantages of two fuel cells, the electrolyte systems of phosphoric acid supported silica on ceramics are recently being tested. In this study, we investigated the nm pore rice husk silica as a support for phosphoric acid and tested the electric conductivity of the silica plate and the characteristics of a prototype fuel cell H2/Pt/H3PO4 / RHS/Pt/O2 at 100-200 degrees C. The conductivity of H3PO4/RHS was 8 mS cm(-1) above 175 degrees C under 200 torr H2O. In the fuel cell, the apparent conductance of the electrolyte from I-V characteristics was 2.45 mS/cm at 160 degrees C under 1 atm H2 and air at present.     

Electronic structure of P-doped ZnO films with p-type conductivity

The electronic structure of laser-deposited P-doped ZnO films was investigated by X-ray absorption near-edge structure spectroscopy (XANES) at the O K-, Zn K-, and Zn L3-edges. While the O K-edge XANES spectrum of the n-type P-doped ZnO demonstrates that the density of unoccupied states, primarily O 2p-P 3sp hybridized states, is significantly high, the O K-edge XANES spectrum of the p-type P-doped ZnO shows a sharp decrease in intensity of the corresponding feature indicating that P replaces O sites in the ZnO lattice, and thereby generating P(O). This produces holes to maintain charge neutrality that are responsible for the p-type behavior of P-doped ZnO. Both the Zn K-, and Zn L3-edge XANES spectra of the P-doped ZnO reveal that Zn plays no significant role in the p-type behavior of ZnO:P.     

Development of a new automatic system for fault tree analysis for chemical process industries

The main purpose of this study was to develop a computer automated tool for fault tree analysis (FTA) in order to minimize the flaws of manual FTA. The automated FTA system developed in this study consists of two steps: 1) automatic fault tree conversion from a digraph, and 2) calculation of the probability of the occurrence of the top event and finding a minimal cut set of the top event. For the first step, we propose a new algorithm for automatic conversion of a digraph to a fault tree. The new digraph-FT conversion algorithm has eight FT generation rules to transform node information that is based on the node characteristics. Failures and faults are classified into three types to easily synthesize fault trees and analyze fault trees precisely. The automatic FTA system was then applied the analysis of real chemical processes to illustrate the effectiveness of the system.     

Oxidation of organics in retentates from reverse osmosis wastewater reuse facilities

The use of membrane processes for wastewater treatment and reuse is rapidly expanding. Organic, inorganic, and biological constituents are effectively removed by reverse osmosis (RO) membrane processes, but concentrate in membrane retentates Disposal of membrane concentrates is a growing concern. Applying advanced oxidation processes (AOPs) to RO retentate is logical because extensive treatment and energy inputs were expended to concentrate the organics, and it is cheaper to treat smaller flowstreams. AOPs (e.g., UV irradiation in the presence of titanium dioxide; UV/TiO₂) can remove a high percentage of organic matter from RO retentates. The combination of AOPs and a simple biological system (e.g., sand filter) can remove higher levels of organic matter at lower UV dosages because AOPs produce biologically degradable material (e.g., organic acids) that have low hydroxyl radical rate constants, meaning that their oxidation, rather than that of the primary organic matter in the RO retentate, dictates the required UV energy inputs. At the highest applied UV dose (10 kWh m⁻3), the dissolved organic carbon (DOC) in the RO retentate decreased from ∼40 to 8 mg L⁻1, of which approximately 6 mg L⁻1 were readily biologically degradable. Therefore, after combined UV treatment and biodegradation, the final DOC concentration was 2 mg L⁻1, representing a 91% removal. These results suggest that UV/TiO₂ plus biodegradation of RO retentates is feasible and would significantly reduce the organic pollutant loading into the environment from wastewater reuse facilities.     

Effect of electronic flame off parameters on copper bonding wire: Free-air ball deformability, heat affected zone length, heat affected zone breaking force

Cu bonding wire is more and more used for interconnections to integrated circuits (ICs) to reduce cost and increase performance compared to Au wire. To eliminate underpad damage for Cu wire applications, it is worthwhile to reduce the hardness of the free-air ball (FAB). Short heat affected zone (HAZ) and high HAZ breaking load are often required for advanced microelectronics packaging in order to decrease the loop height and thereby the package thickness.Online measurements of deformability and HAZ breaking force at temperatures close to the bonding temperature of 220 °C are new tools used in this study to evaluate the effects of electronic flame off (EFO) current and firing time on the Cu FAB deformability and the HAZ length and tensile strength. FABs with 50 μm diameter formed from a 25 μm diameter Cu wire with a breaking load of 118.6 mN were used. EFO currents and firing times ranged from 40 to 250 mA and 0.11 to 0.90 ms, respectively. Average FAB deformability factors, HAZ breaking forces, and HAZ lengths were in the rounded ranges of 36.64–44.09% (with a deformation force of 0.60 N), 107.7–116.8 mN, and 167–215 μm, respectively. When produced with 250 mA current during 0.11 ms, the FABs are 7.01–7.89% more deformable than when produced with 45 mA during 0.9 ms, the HAZ breaking force is 7.53–9.37% higher, and the HAZ length is 7–90 μm shorter.     

Safe Navigation of a Mobile Robot Considering Visibility of Environment

We present one approach to achieve safe navigation in an indoor dynamic environment. So far, there have been various useful collision avoidance algorithms and path planning schemes. However, those algorithms possess fundamental limitations in that the robot can avoid only ldquovisiblerdquo ones among surrounded obstacles. In a real environment, it is not possible to detect all the dynamic obstacles around the robot. There are many occluded regions due to the limited field of view. In order to avoid collisions, it is desirable to exploit visibility information. This paper proposes a safe navigation scheme to reduce collision risk considering occluded dynamic obstacles. The robot's motion is controlled by the hybrid control scheme. The possibility of collision is dually reflected to path planning and speed control. The proposed scheme clearly indicates the structural procedure on how to model and to exploit the risk of navigation. The proposed scheme is experimentally tested in a real office building. The experimental results show that the robot moves along the safe path to obtain sufficient field of view. In addition, safe speed constraints are applied in motion control. It is experimentally verified that a robot safely navigates in dynamic indoor environment by adopting the proposed scheme.     

Key features of the KSTAR helium refrigeration system

KSTAR is a fully superconducting (SC) tokamak consisting of 30 magnet coils made of Nb₃Sn and NbTi. To keep the SC magnets at proper operating conditions, all cold components of KSTAR such as the SC bus-lines, current leads, and thermal shields must be maintained at the respective cryogenic temperatures by using a helium refrigeration system (HRS). The main components of the HRS can be classified into the warm compression system (WCS) and the cryogenic systems according to their operating temperature levels. The HRS had been manufactured, installed and commissioned until March 2008 and has been operated for KSTAR campaign since then. In this paper, the result of the commissioning, operation and reliability record of the KSTAR HRS will be presented.