Magnetic imaging of layer-by-layer reversal in Co/Pt multilayers with perpendicular anisotropy

For very thin Co layers, the exchange coupling between adjacent Co layers in Co∕Pt multilayers is ferromagnetic and the coupling strength varies nonmonotonically as the nonmagnetic Pt layer thickness (t_Pt) ranges from 3 to 75 Å. We report on the magnetization reversal process in a series of [Co(4 Å)/Pt(t_Pt)]_N multilayers observed by magneto-optical Kerr microscopy as a function of t_Pt and layer repetition N. The images reveal the evolution of magnetic reversal processes that strongly depend on t_Pt and therefore on the interlayer coupling. For Co/Pt multilayers with small t_Pt, e.g., 11 Å, where the Co layers are strongly coupled, the whole multilayer switches as a single ferromagnet. As Co layers are separated farther and become weakly coupled, e.g., at t_Pt=41 Å, layer-by-layer magnetic reversal is observed. The Kerr images reveal metastable magnetic domain configurations during layer-by-layer switching which is not evident in the measured hysteresis loops during the abrupt magnetic reversal for Co∕Pt multilayers with weak interlayer coupling at large t_Pt

Reconstruction Control of Magnetic Properties during Epitaxial Growth of Ferromagnetic Mn_3-δGa on Wurtzite GaN(0001)

Binary ferromagnetic Mn_3-δGa (1.2<3-δ≤1.5) crystalline thin films have been epitaxially grown on wurtzite GaN(0001) surfaces using rf N-plasma molecular beam epitaxy. The film structure is face-centered tetragonal with CuAu type-I (L1_0) ordering with (111) orientation. The in-plane epitaxial relationship to GaN is nearly ideal with [11̅ 0]_MnGa∥[11̅ 00]_GaN and [112̅ ]_MnGa∥[112̅ 0]_GaN. We observe magnetic anisotropy along both the in-plane and out-of-plane directions. The magnetic moments are found to depend on the Mn/(Mn+Ga) flux ratio and can be controlled by observation of the surface reconstruction during growth, which varies from 1×1 to 2×2 with increasing Mn stoichiometry

Applicability of remote sensor data to geologic analysis of the Bonanza test site Colorado

There are no author-identified significant results in this report

Application of remote sensor data to geologic analysis of the Bonanza test site Colorado

Research activities on geologic remote sensing applications for Colorado are summarized. Projects include: regional and detailed geologic mapping, surficial and engineering geology, fracture studies, uranium exploration, hydrology, and data reduction and enhancement. The acquisition of remote sensor data is also discussed

The Lantern Vol. 16, No. 1, Fall 1947

• A Little Light • Social Solidarity • The Struggle • 1949 Report • Blues • Angel\u27s Wings • Street Death • The Giant • Not Alone • B or Something • After Argument • Friendship • Built That Way • The Passing • Freshman • Asleep • John J. Heilemannhttps://digitalcommons.ursinus.edu/lantern/1043/thumbnail.jp

A critical review of the formation of mono- and dicarboxylated metabolic intermediates of alkylphenol polyethoxylates during wastewater treatment and their environmental significance

This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2010 Taylor & Francis.Alkylphenoxyacetic acids, the metabolic biodegradation products of alkylphenol ethoxylates, are commonly found in wastewaters and sewage effluents. These persistent hydrophilic derivatives possess intrinsic estrogenic activity, which can mimic natural hormones. Their concentrations increase through the sewage treatment works as a result of biodegradation and biotransformation, and when discharged can disrupt endocrine function in fish. These acidic metabolites represent the dominant alkylphenolic compounds found in wastewater effluent and their presence is cause for concern as, potentially, through further biotransformation and biodegradation, they can act as sources of nonylphenol, which is toxic and estrogenic. The authors aim to assess the mechanisms of formation as well as elimination of alkylphenoxyacetic acids within conventional sewage treatment works with the emphasis on the activated sludge process. In addition, they evaluate the various factors influencing their degradation and formation in laboratory scale and full-scale systems. The environmental implications of these compounds are considered, as is the need for tertiary treatment processes for their removal

Renal Sodium Gradient Orchestrates a Dynamic Antibacterial Defense Zone.

Lower urinary tract infections are among the most common human bacterial infections, but extension to the kidneys is rare. This has been attributed to mechanical forces, such as urine flow, that prevent the ascent of bladder microbes. Here, we show that the regional hypersalinity, required for the kidney's urine-concentrating function, instructs epithelial cells to produce chemokines that localize monocyte-derived mononuclear phagocytes (MNPs) to the medulla. This hypersaline environment also increases the intrinsic bactericidal and neutrophil chemotactic activities of MNPs to generate a zone of defense. Because MNP positioning and function are dynamically regulated by the renal salt gradient, we find that patients with urinary concentrating defects are susceptible to kidney infection. Our work reveals a critical accessory role for the homeostatic function of a vital organ in optimizing tissue defense