Physical Sciences and Mathematics | Open Access Articles

ปรากฏการณ์ความแห้งแล้งในรัชสมัยของ พระบาทสมเด็จพระจอมเกล้าเจ้าอยู่หัวและการแก้ไขปัญหาของพระองค์, ทวีศักดิ์ ปิยกาญจน์

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การพัฒนาดัชนีชี้วัดคุณภาพสิ่งแวดล้อมชุมชน, มัธยา รักษาสัตย์

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การประชุมใหญ่สมัชชาการอนุรักษ์ สิ่งแวดล้อมโลก ครั้งที่ 3, สุพัตรา วิเศษสุข

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Reach ระเบียบว่าด้วยสารเคมีของสหภาพยุโรป, รดาวรรณ ศิลปโภชากุล

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วิวัฒนาการของเทคโนโลยีการฟื้นฟูพื้นที่ปนเปื้อนของเสียอันตราย, พันธวัส สัมพันธ์พานิช

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เฟอร์เรตกับการปรับปรุงคุณภาพน้ำ, ศีลาวุธ ดำรงศิริ, เขมรัฐ โอสถาพันธุ์

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การปรับปรุงคุณภาพสาหร่ายช่อพริกไทย เพื่อกำจัดโลหะหนัก, ประทีป สุทธิปริญญานนท์

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"สึนามิ" ธรณีพิบัติภัยที่ชาวโลกต้องจดจำ, สิริพร แก่นสียา

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เสียงดัง....อันตรายใกล้ตัว ปัญหาที่ถูกมองข้าม, สิริพร แก่นสียา

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สิ่งแวดล้อมน่ารู้

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สร้างโลกสวย

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Exclusive Ρ0 Meson Electroproduction From Hydrogen At Clas, C. Hadjidakis, M. Guidal, M. Garçon, J.-M. Laget, E. S. Smith, M. Vanderhaeghen, G. Adams, P. Ambrozewicz, E. Anciant, M. Anghinolfi, H. Bagdasaryan, K. V. Dharmawardane, G. E. Dodge, T. A. Forest, G. Gavalian, M. Guler, C. E. Hyde-Wright, A. Klein, A. V. Klimenko, S. E. Kuhn, R. A. Niyazov, L. M. Qin, F. Sabatie, L. B. Weinstein, J. Yun

Physics Faculty Publications

The longitudinal and transverse components of the cross section for the ep → e′ pρ⁰ reaction were measured in Hall B at Jefferson Laboratory using the CLAS detector. The data were taken with a 4.247 GeV electron beam and were analyzed in a range of ^xB from 0.2 to 0.6 and of Q² from 1.5 to 3.0 GeV2. The data are compared to a Regge model based on effective hadronic degrees of freedom and to a calculation based on Generalized Parton Distributions. It is found that, at our lowest ^xB values, the transverse part of the …

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Exclusive Photoproduction Of The Cascade Ξ Hyperons, H. Bagdasaryan, M. Bektasoglu, K. V. Dharmawardane, G. E. Dodge, T. A. Forest, G. Gavalian, N. Guler, C. E. Hyde-Wright, A. V. Klimenko, S. E. Kuhn, L. M. Qin, L. B. Weinstein, J. Yun, Et Al., Clas Collaboration

Physics Faculty Publications

We report on the first measurement of exclusive Ξ^-(1321) hyperon photoproduction in 𝛾p → K⁺K⁺Ξ^- for 3.2 < E𝛾 < 3.9 GeV. The final state is identified by the missing mass in p(𝛾,K⁺K⁺)X measured with the CLAS detector at Jefferson Laboratory. We have detected a significant number of the ground state Ξ^-(1321)1/2⁺ and have estimated the total cross section for its production. We also have strong evidence for the first excited state Ξ^-(1530)3/2⁺. Photoproduction provides a copious source of Ξ's. We discuss the possibilities of a search for the recently proposed Ξ₅^- and Ξ₅^{+ …}

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Global Analysis Of Data On The Proton Structure Function G₁ And The Extraction Of Its Moments, M. Osipenko, S. Simula, W. Melnitchouk, P. Bosted, V. Burkert, E. Christy, K. Griffioen, C. Keppel, S. Kuhn, G. Ricco

Physics Faculty Publications

Inspired by recent measurements with the CLAS detector at Jefferson Lab, we perform a self-consistent analysis of world data on the proton structure function g₁ in the range 0.17 < Q² < 30 (GeV/c)². We compute for the first time low-order moments of g, and study their evolution from small to large values of Q². The analysis includes the latest data on both the unpolarized inclusive cross sections and the ratio R = σ _L/σ_T from Jefferson Lab, as well as a new model for the transverse asymmetry A₂ in the resonance region. The contributions of …

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Higher Twist Analysis Of The Proton G₁ Structure Function, M. Osipenko, W. Melnitchouk, S. Simula, P. Bosted, V. Burkert, M. E. Christy, K. Griffioen, C. Keppel, S. E. Kuhn

Physics Faculty Publications

We perform a global analysis of all available spin-dependent proton structure function data, covering a large range of Q², 1 ⩽ Q² ⩽ 30 GeV², and calculate the lowest moment of the g₁ structure function as a function of Q². From the Q² dependence of the lowest moment we extract matrix elements of twist-4 operators, and determine the color electric and magnetic polarizabilities of the proton to be X_E= 0.026 ± 0.015(stat) ± ^0.021_0.024 (sys) and X_B= -0.013 ∓ 0.007(stat) ∓ ^0.010 _0.012(sys), respectively.

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An Inventory Of Rangelands In Part Of The Broome Shire, Western Australia, W E. Cotching

Technical Bulletins

The inventory of rangelands in part of the Broome Shire in Western Australia was undertaken by DAFWA between 1989 and 1990. It describes and maps the natural resources of the region’s pastoral leasehold land. This survey report provides a baseline record of the existence and condition of the natural area’s resources, to assist with the planning and implementation of land management practices. The report identified and described the condition of soils, landforms, vegetation, habitat, ecosystems, and declared plants and animals. It also assessed the impact of pastoralism and made land management recommendations. The survey of part of the Broome Shire …

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Solvent Extraction Separation And Determination Of Yttrium With Cyanex272, Manjusha Karve, Bhagyashree P. Vaidya

Department of Chemistry and Biochemistry Faculty Scholarship and Creative Works

A simple and selective method for the liquid - liquid extraction of yttrium with Cyanex272 is presented. The influence of the pH of aqueous phase, concentration of extractant, nature of diluent, extraction time, type of stripping agent and stripping time were evaluated to optimize the conditions for quantitative extraction of yttrium. The effect of certain foreign ions on the extraction of yttrium was studied. Yttrium was quantitatively extracted at pH = 7.0 with 5 x 10-4 M Cyanex272 in xylene. It was stripped from the organic phase with 4M nitric acid and determined spectrophotometrically with Arsenazo (Ill) at 650nm.

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Tylosaurus Kansasensis, A New Species Of Tylosaurine (Squamata, Mosasauridae) From The Niobrara Chalk Of Western Kansas, Usa, M. J. Everhart

Sternberg Museum of Natural History Faculty Publications

Tylosaurus kansasensis sp. nov. is described herein on the basis of thirteen specimens collected from the Smoky Hill Chalk (upper Coniacian) of western Kansas, USA. The new species, originally designated Tylosaurus n. sp., co-occurred with T. nepaeolicus and exhibits a number of primitive characters that place it in a basal position in the mosasaur phylogeny. Among the key differences separating this species from other tylosaurines are a shortened, more rounded pre-dental process of the premaxilla, a distinctive quadrate lacking an infrastapedial process, and a parietal foramen located adjacent to the frontal-parietal suture.

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Monotone Periodic Orbits For Torus Homeomorphisms, Kamlesh Parwani

Kamlesh Parwani

Let f be a homeomorphism of the torus isotopic to the identity and suppose that there exists a periodic orbit with a non-zero rotation vector (p/q,r/q), then f has a topologically monotone periodic orbit with the same rotation vector.

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Agricultural Resource Priorities And Recommendations For The Avon River Basin Natural Resource Management Strategy, Paul D. Galloway, C E. Mcconnell, D W. Cummins, K Ohlsen

Resource management technical reports

This report for the Avon Natural Resource Management Strategy provides an assessment of the current status of land resources throughout the Avon River Basin in Western Australia. It identifies the sub-regions and landscape components of the area and the land resource assets. The greatest threats are salinity, soil acidification, subsurface compaction, waterlogging, water and wind erosion, and biosecurity.

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Liquid Crystal Optics For Communications, Signal Processing And 3-D Microscopic Imaging, Sajjad Khan

Electronic Theses and Dissertations

This dissertation proposes, studies and experimentally demonstrates novel liquid crystal (LC) optics to solve challenging problems in RF and photonic signal processing, freespace and fiber optic communications and microscopic imaging. These include free-space optical scanners for military and optical wireless applications, variable fiber-optic attenuators for optical communications, photonic control techniques for phased array antennas and radar, and 3-D microscopic imaging. At the heart of the applications demonstrated in this thesis are LC devices that are non-pixelated and can be controlled either electrically or optically. Instead of the typical pixel-by-pixel control as is custom in LC devices, the phase profile across …

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Coherence Properties Of Optical Near-Fields, Adela Apostol

Electronic Theses and Dissertations

Next generation photonics-based technologies will ultimately rely on novel materials and devices. For this purpose, phenomena at subwavelength scales are being studied to advance both fundamental knowledge and experimental capabilities. In this dissertation, concepts specific to near-field optics and experimental capabilities specific to near-field microscopy are used to investigate various aspects of the statistical properties of random electromagnetic fields in the vicinity of optically inhomogeneous media which emit or scatter radiation. The properties of such fields are being characterized within the frame of the coherence theory. While successful in describing the far-field properties of optical fields, the fundamental results of …

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Performance By Unified Model Analysis (Puma), Murray Woodside, Dorina C. Petriu, Dorin B. Petriu, Hui Shen, Toqeer A. Israr, Jose Merseguer

Faculty Research & Creative Activity

Evaluation of non-functional properties of a design (such as performance, dependability, security, etc.) can be enabled by design annotations specific to the property to be evaluated. Performance properties, for instance, can be annotated on UML designs by using the "UML Profile for Schedulability, Performance and Time (SPT)". However the communication between the design description in UML and the tools used for non-functional properties evaluation requires support, particularly for performance where there are many alternative performance analysis tools that might be applied. This paper describes a tool architecture called PUMA, which provides a unified interface between different kinds of design information …

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Experimental Studies Of Light Propagation And Storage In Warm Atomic Gases, H. Gao, Mark A. Rosenberry, J. Wang, Herman Batelaan

Department of Physics and Astronomy: Faculty Publications

We report on an experimental study of slow pulse propagation and polarization storage of light in an atomic vapour for pulse durations ranging from several μs to 100 μs, for non-zero magnetic fields, for temperatures ranging from 65 to 90 °C and for two different rubidium isotopes. The results confirm the presence of the electromagnetically induced transparency window as predicted by Lukin (1997 Phys. Rev. Lett. 79 2959). We show that time-dependent optical rotation can mask the storage of light signal, and demonstrate storage of light for the ⁸⁵Rb isotope.

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2,2':6',2"-Terpyridine 1,1"-Dioxide Dihydrate, Kraig A. Wheeler, Scott E. Mckay, Robert W. Lashlee Iii

Faculty Research and Creative Activity

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The Thermal Degradation Of Bisphenol A Polycarbonate In Air, Bok Nam Jang, Charles A. Wilkie

Chemistry Faculty Research and Publications

The thermal degradation of polycarbonate in air was studied as a function of mass loss using TGA/FTIR, GC/MS and LC/MS. In the main degradation region, 480–560 °C, the assigned structures of smaller molecules and linear molecules that evolved in air were very similar to those obtained from the degradation in nitrogen; the degradation of polycarbonate follows chain scission of the isopropylidene linkage, in agreement with the bond dissociation energies, and hydrolysis/alcoholysis of carbonate linkage. Compared to the degradation in nitrogen, some differences were observed primarily in the beginning stage of degradation. Oxygen may facilitate branching as well as radical formation …

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Polystyrene Nanocomposites Based On Carbazole-Containing Surfactants, Grace Chigwada, David D. Jiang, Charles A. Wilkie

Chemistry Faculty Research and Publications

New organically-modified clays containing a carbazole unit were prepared and the number of long alkyl chains on the surfactant was varied. The clay was used to prepare polystyrene nanocomposites by both bulk polymerization and melt blending. The dispersion of these clays in the polymer matrix was evaluated using X-ray diffraction (XRD) and transmission electron microscopy (TEM). The thermal stability of the clays and the nanocomposites were analyzed by thermogravimetric analysis (TGA) while the fire properties were evaluated by cone calorimetry. If more than two alkyl chains were present, the gallery spacing is apparently overcrowded, leading to poor dispersion. Bulk polymerization …

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Feedback Stabilization Of Inverted Pendulum Models, Bruce Cox

Theses and Dissertations

Many mechanical systems exhibit nonlinear movement and are subject to perturbations from a desired equilibrium state. These perturbations can greatly reduce the efficiency of the systems. It is therefore desirous to analyze the asymptotic stabilizability of an equilibrium solution of nonlinear systems; an excellent method of performing these analyses is through study of Jacobian linearization's and their properties. Two enlightening examples of nonlinear mechanical systems are the Simple Inverted Pendulum and the Inverted Pendulum on a Cart (PoC). These examples provide insight into both the feasibility and usability of Jacobian linearizations of nonlinear systems, as well as demonstrate the concepts …

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The Relationship Between The Solubility Parameter Of Polymers And The Clay-Dispersion In Polymer/Clay Nanocomposites And The Role Of The Surfactant, Bok Nam Jang, Dongyan Wang, Charles A. Wilkie

Chemistry Faculty Research and Publications

Nanocomposites were prepared of polymers having different solubility parameters and pristine or organically modified clays, and the dispersion of clay in the polymer was evaluated using X-ray diffraction and transmission electron microscopy. The solubility parameters of both the polymers and surfactants of interest were calculated according to the group contribution method and correlated with the clay morphology. A close relationship between the solubility parameter of the polymer and the clay morphology was observed. The clay has a very polar group, so the higher is the solubility parameter of the polymer, the larger is the d spacing of the clay that …

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Carbon Monoxide Oxidation On Nanoparticle Catalysts And Gas Phase Reactions Of Small Molecules And Volatile Organics With Metal Cations, Khaled Mohammad Eqab Saoud

Theses and Dissertations

This dissertation demonstrates the application of a vapor phase method to synthesize supported and unsupported nanoparticle catalysts for CO oxidation. The method is based on the Laser Vaporization/Controlled Condensation (LVCC) technique. The first part of this dissertation presents the vapor phase synthesis and characterization of gold nanoparticles supported on a variety of oxide supports such as CeO2, TiO2, CuO and MgO.The results indicate that Au nanoparticles supported on CeO2 exhibit higher catalytic activity than Au supported on other oxides. The high activity of the Au/CeO2 catalyst is attributed to the strong interaction of Au with CeO2. The results also indicate …

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Full-Text Articles in Physical Sciences and Mathematics

Thai Environment

การพัฒนาดัชนีชี้วัดคุณภาพสิ่งแวดล้อมชุมชน, มัธยา รักษาสัตย์

Thai Environment

การประชุมใหญ่สมัชชาการอนุรักษ์ สิ่งแวดล้อมโลก ครั้งที่ 3, สุพัตรา วิเศษสุข

Thai Environment

Reach ระเบียบว่าด้วยสารเคมีของสหภาพยุโรป, รดาวรรณ ศิลปโภชากุล

Thai Environment

วิวัฒนาการของเทคโนโลยีการฟื้นฟูพื้นที่ปนเปื้อนของเสียอันตราย, พันธวัส สัมพันธ์พานิช

Thai Environment

เฟอร์เรตกับการปรับปรุงคุณภาพน้ำ, ศีลาวุธ ดำรงศิริ, เขมรัฐ โอสถาพันธุ์

Thai Environment

การปรับปรุงคุณภาพสาหร่ายช่อพริกไทย เพื่อกำจัดโลหะหนัก, ประทีป สุทธิปริญญานนท์

Thai Environment

"สึนามิ" ธรณีพิบัติภัยที่ชาวโลกต้องจดจำ, สิริพร แก่นสียา

Thai Environment

เสียงดัง....อันตรายใกล้ตัว ปัญหาที่ถูกมองข้าม, สิริพร แก่นสียา

Thai Environment

สิ่งแวดล้อมน่ารู้

Thai Environment

สร้างโลกสวย

Thai Environment

Physics Faculty Publications

Exclusive Photoproduction Of The Cascade Ξ Hyperons, H. Bagdasaryan, M. Bektasoglu, K. V. Dharmawardane, G. E. Dodge, T. A. Forest, G. Gavalian, N. Guler, C. E. Hyde-Wright, A. V. Klimenko, S. E. Kuhn, L. M. Qin, L. B. Weinstein, J. Yun, Et Al., Clas Collaboration

Physics Faculty Publications

Global Analysis Of Data On The Proton Structure Function G₁ And The Extraction Of Its Moments, M. Osipenko, S. Simula, W. Melnitchouk, P. Bosted, V. Burkert, E. Christy, K. Griffioen, C. Keppel, S. Kuhn, G. Ricco

Physics Faculty Publications

Higher Twist Analysis Of The Proton G₁ Structure Function, M. Osipenko, W. Melnitchouk, S. Simula, P. Bosted, V. Burkert, M. E. Christy, K. Griffioen, C. Keppel, S. E. Kuhn

Physics Faculty Publications

An Inventory Of Rangelands In Part Of The Broome Shire, Western Australia, W E. Cotching

Technical Bulletins

Solvent Extraction Separation And Determination Of Yttrium With Cyanex272, Manjusha Karve, Bhagyashree P. Vaidya

Department of Chemistry and Biochemistry Faculty Scholarship and Creative Works

Tylosaurus Kansasensis, A New Species Of Tylosaurine (Squamata, Mosasauridae) From The Niobrara Chalk Of Western Kansas, Usa, M. J. Everhart

Sternberg Museum of Natural History Faculty Publications

Monotone Periodic Orbits For Torus Homeomorphisms, Kamlesh Parwani

Kamlesh Parwani

Agricultural Resource Priorities And Recommendations For The Avon River Basin Natural Resource Management Strategy, Paul D. Galloway, C E. Mcconnell, D W. Cummins, K Ohlsen

Resource management technical reports

Liquid Crystal Optics For Communications, Signal Processing And 3-D Microscopic Imaging, Sajjad Khan

Electronic Theses and Dissertations

Coherence Properties Of Optical Near-Fields, Adela Apostol

Electronic Theses and Dissertations

Performance By Unified Model Analysis (Puma), Murray Woodside, Dorina C. Petriu, Dorin B. Petriu, Hui Shen, Toqeer A. Israr, Jose Merseguer

Faculty Research & Creative Activity

Experimental Studies Of Light Propagation And Storage In Warm Atomic Gases, H. Gao, Mark A. Rosenberry, J. Wang, Herman Batelaan

Department of Physics and Astronomy: Faculty Publications

2,2':6',2"-Terpyridine 1,1"-Dioxide Dihydrate, Kraig A. Wheeler, Scott E. Mckay, Robert W. Lashlee Iii

Faculty Research and Creative Activity

The Thermal Degradation Of Bisphenol A Polycarbonate In Air, Bok Nam Jang, Charles A. Wilkie

Chemistry Faculty Research and Publications

Polystyrene Nanocomposites Based On Carbazole-Containing Surfactants, Grace Chigwada, David D. Jiang, Charles A. Wilkie

Chemistry Faculty Research and Publications

Feedback Stabilization Of Inverted Pendulum Models, Bruce Cox

Theses and Dissertations

The Relationship Between The Solubility Parameter Of Polymers And The Clay-Dispersion In Polymer/Clay Nanocomposites And The Role Of The Surfactant, Bok Nam Jang, Dongyan Wang, Charles A. Wilkie

Chemistry Faculty Research and Publications

Carbon Monoxide Oxidation On Nanoparticle Catalysts And Gas Phase Reactions Of Small Molecules And Volatile Organics With Metal Cations, Khaled Mohammad Eqab Saoud

Theses and Dissertations