Oklahoma State University–Stillwater

About: Oklahoma State University–Stillwater is a education organization based out in Stillwater, Oklahoma, United States. It is known for research contribution in the topics: Population & Large Hadron Collider. The organization has 18267 authors who have published 36743 publications receiving 1107500 citations. The organization is also known as: Oklahoma State University & OKState.

Highly effective adsorption of heavy metal ions by a thiol-functionalized magnesium phyllosilicate clay.

Abstract: A thiol-functionalized layered magnesium phyllosilicate material (called Mg-MTMS), prepared by a direct and cost-effective co-condensation synthesis, has been investigated as a high-capacity adsorbent for heavy metal ions. Structural characterization by powder X-ray diffraction, infrared spectroscopy, solid-state 13C and 29Si NMR spectroscopies, and elemental analyses confirms the smectite-type structure and the high organic moiety content of this material. Mg-MTMS was found to be highly effective for the adsorption of Hg(II), Pb(II), and Cd(II) ions, exhibiting unprecedented metal ion uptake capacities of 603, 365, and 210 mg of metal/g of adsorbent, respectively. Mg-MTMS shows an equivalent affinity for the three metal ions, removing them from mixed metal solutions with an equal ion uptake capacity (∼400 mg of metal/g of adsorbent). Metal-loaded Mg-MTMS can be regenerated by acid treatment without altering the adsorbent properties. The high effectiveness of Mg-MTMS for the capture of metal ions is attri...

U-Th-Pb Dating of Phosphate Minerals

Abstract: ### Introduction The dominant occurrence of phosphate minerals in crystalline rocks is as accessory phases, most notably apatite, monazite, and xenotime. Because these minerals tend, to varying degrees, to partition U and Th into their structures they can often contain the majority of those elements in a rock. These three phases, again to varying degrees, tend not to incorporate significant amounts of Pb during crystallization and thus were early candidates for utilization as U-Th-Pb geochronometers. The ideal U-Th-Pb geochronometer would be a phase that is stable over all possible environmental conditions and is quantitatively retentive of parent and daughter isotopes. In fact, the silicate zircon comes reasonably close to meeting these criteria. Zircon has a broad stability field, is refractory under a wide variety of geologic environments (e.g., weathering, sedimentary transport, anatexis, and metamorphism), and can be highly retentive of daughter products in the U-Th-Pb decay system. However, the limit of zircon as an ideal chronometer lies only in its limited resistance to auto-irradiation damage that can render it metamict. The phosphate minerals apatite, monazite and xenotime have a more restricted range of stability and, to varying degrees, are incompletely retentive of Pb under crustal conditions, but they are resilient to radiation damage. Thus interpretation of results from these geochronometers requires a greater understanding of their structure, stability, and kinetic properties than does zircon. This chapter is aimed at providing the reader with an introduction to those characteristics that will facilitate interpretation of the occasionally problematic nature of phosphate U-Th-Pb dating results. ### The U-Th-Pb dating system #### U and Th decay. Nuclei approaching one hundred protons are unstable because the strong nuclear force, which acts to hold neutrons and protons together, is about 100 times greater than electromagnetic repulsion. Both uranium (92 protons) and thorium (90 protons) decay by emission of a 4He nucleus (or α particle), which lowers the …

Monkeypox Transmission and Pathogenesis in Prairie Dogs

Abstract: During May and June 2003, the first cluster of human monkeypox cases in the United States was reported. Most patients with this febrile vesicular rash illness presumably acquired the infection from prairie dogs. Monkeypox virus was demonstrated by using polymerase chain reaction in two prairie dogs in which pathologic studies showed necrotizing bronchopneumonia, conjunctivitis, and tongue ulceration. Immunohistochemical assays for orthopoxviruses demonstrated abundant viral antigens in surface epithelial cells of lesions in conjunctiva and tongue, with less amounts in adjacent macrophages, fibroblasts, and connective tissues. Viral antigens in the lung were abundant in bronchial epithelial cells, macrophages, and fibroblasts. Virus isolation and electron microscopy demonstrated active viral replication in lungs and tongue. These findings indicate that both respiratory and direct mucocutaneous exposures are potentially important routes of transmission of monkeypox virus between rodents and to humans. Prairie dogs offer insights into transmission, pathogenesis, and new vaccine and treatment trials because they are susceptible to severe monkeypox infection.

Thin-film piezoelectric-on-silicon resonators for high-frequency reference oscillator applications

Abstract: This paper studies the application of lateral bulk acoustic thin-film piezoelectric-on-substrate (TPoS) resonators in high-frequency reference oscillators Low-motional impedance TPoS resonators are designed and fabricated in 2 classes--high-order and coupled-array Devices of each class are used to assemble reference oscillators and the performance characteristics of the oscillators are measured and discussed Since the motional impedance of these devices is small, the transimpedance amplifier (TIA) in the oscillator loop can be reduced to a single transistor and 3 resistors, a format that is very power-efficient The lowest reported power consumption is ~350 muW for an oscillator operating at ~106 MHz A passive temperature compensation method is also utilized bThis paper studies the application of lateral bulk acoustic thin-film piezoelectric-on-substrate (TPoS) resonators in high-frequency reference oscillators Low-motionalimpedance TPoS resonators are designed and fabricated in 2 classes--high-order and coupled-array Devices of each class are used to assemble reference oscillators and the performance characteristics of the oscillators are measured and discussed Since the motional impedance of these devices is small, the transimpedance amplifier (TIA) in the oscillator loop can be reduced to a single transistor and 3 resistors, a format that is very power-efficient The lowest reported power consumption is ~350 muW for an oscillator operating at ~106 MHz A passive temperature compensation method is also utilized by including the buried oxide layer of the silicon-on-insulator (SOI) substrate in the structural resonant body of the device, and a very small (-24 ppm/degC) temperature coefficient of frequency is obtained for an 82-MHz oscillatory including the buried oxide layer of the silicon-on-insulator (SOI) substrate in the structural resonant body of the device, and a very small (-24 ppm/degC) temperature coefficient of frequency is obtained for an 82-MHz oscillator