Investigation of Loss of Generation Disturbances in the Florida Power and Light Company Network by the Transient Energy Function Method

This paper deals with the investigation of the loss of generation disturbances by the transient energy function (TEF) method. It describes the modeling of the loss of generation disturbance and the post-disturbance conditions. A technique for simulating the out-of-step impedance relay operation following loss of generation is developed and the transient energy margin obtained from the TEF method is related to the out-of-step impedance relay setting. The procedure is applied to two cases of loss of generation in the Florida Power & Light Company network.     

Oocyte donation: does a previous attempt affect a subsequent attempt?

Epidermal infiltration by neoplastic CD4+ T cells is a characteristic histologic feature of early stage mycosis fungoides, the most common type of cutaneous T cell lymphoma (CTCL). The mechanisms involved in epidermotropism are unknown. It has been suggested that the CXC chemokines IL-8 and interferon-gamma inducible protein 10 (IP-10) may play a role, but evidence that these chemokines are produced within the epidermis in epidermotropic CTCL is lacking. In this study skin biopsies from 17 CTCL patients, including 12 mycosis fungoides, four pleomorphic CTCL, and one CD8+ CTCL, were investigated for epidermal IL-8 and IP-10 mRNA expression by RNA in situ hybridization. In addition, the expression of monokine induced by gamma-interferon (Mig) mRNA, a CXC chemokine closely related to IP-10, was studied as well. The expression of IL-8 receptors A and B (CXCR1 and CXCR2, respectively) was investigated by immunohistochemistry. The results were correlated with the number and phenotype of epidermotropic T cells. Epidermal expression of IP-10 and Mig mRNA was detected in 10 of 11 and seven of 11 epidermotropic CTCL, respectively, but not in five nonepidermotropic CTCL biopsies or normal human skin. Epidermal IP-10 and Mig mRNA expression correlated with epidermal infiltration of CD4+ T cells, but not of CD8+ T cells. IL-8 mRNA was demonstrated in the epidermis of only two of 15 CTCL biopsies, and was associated, in both cases, with accumulation of neutrophils. Consistently, immunostaining of the (intraepidermal) T cells with antibodies against CXCR1 and CXCR2 was not observed. In conclusion, the results of this study indicate that IP-10, and to a lesser extent Mig, but not IL-8 is involved in the preferential infiltration of neoplastic CD4+ T cells in CTCL.     

Partition characteristics of radionuclides during a melt decontamination of a contaminated metal waste

Melt decontamination of radioactive contaminated metal waste using arc melting process is investigated the characteristic behavior phenomena of radioisotope cobalt-60 (⁶⁰Co) and cesium-137 (¹³⁷Cs) from a molten ingot, slag and dust for the effect of the basicity and various slag types. The composition of the slag former used to capture the contaminants (⁶⁰Co, ¹³⁷Cs) during the melt decontamination process generally consisted of silica (SiO₂), calcium oxide (CaO) and aluminum oxide (Al₂O₃). Also, calcium fluoride (CaF₂), magnesium oxide (MgO), and ferric oxide (Fe₂O₃) were added to provide an increase in the slag fluidity and oxidative potential. More ⁶⁰Co was transfer to the slag phase in the carbon steel than the stainless steel. Most of the ⁶⁰Co remained in the ingot phase at about above 90% present. ⁶⁰Co was removed from the ingot phase to slag phase by up to 12% at about 0.8 of the slag basicity in carbon steel. There was found that significant amounts of ⁶⁰Co remain in the ferric oxide slag at up to 32%. Flux containing CaF₂ was significantly captured to the slag phase by up to 30%. In all the tests, ¹³⁷Cs was completely eliminated from the melt of the stainless steel as well as the carbon steel and distributed to the slag and dust phase. In the slag basicity at 0.5, a maximum of 25% of the ⁶⁰Cs remained in the slag phase to the carbon steel. Fluoride slags favor a capture of cesium in the slag. A maximum of 30% of the ¹³⁷Cs remained in a ferric oxide slag.     

Fabrication of Thin-Film SrCe0.9Eu0.1O3−δ Hydrogen Separation Membranes on Ni–SrCeO3 Porous Tubular Supports

SrCe_0.9Eu_0.1O_3−δ thin-film (∼30 μm) tubular hydrogen separation membranes were developed in order to obtain high hydrogen fluxes. Fifteen centimeters long, one end closed, NiO–SrCeO₃ tubular supports were fabricated by tape casting, followed by rolling the green tape on a circular rod. SrCe_0.9Eu_0.1O_3−δ powders were prepared by the citrate process and coated on partially sintered NiO–SrCeO₃ tubular supports. Leakage-free hydrogen membrane cells were obtained by adjusting the presintering and final sintering temperatures to reduce the difference of linear shrinkage rates between SrCe_0.9Eu_0.1O_3−δ thin films and NiO–SrCeO₃ supports. A hydrogen flux of 2.2 cm³/min was obtained for the SrCe_0.9Eu_0.1O_3−δ on Ni–SrCeO₃ tubular hydrogen separation membranes at 900°C using 25% H₂ balanced with Ar and 3% H₂O as the feed gas and He as the sweep gas. Thus, a 40% single pass yield of pure H₂ was achieved with this membrane.