The total kinetic energy release and fission mass distributions for the fast neutron (En = 3–100 MeV) induced fission of 232Th, 233U, 235U, 237Np, 239Pu, 240Pu, and 242Pu have been measured using the LANSCE facility. The neutron energies were deduced from time-of- flight measurements. The fission fragments were detected using...
Linden (Tilia spp.), a profusely flowering temperate tree that provides bees with vital pollen and nectar, has been associated with bumble bee (Bombus spp.) mortality in Europe and North America. Bee deaths have been attributed, with inadequate evidence, to toxicity from mannose in nectar or starvation due to low nectar...
Researcher innovation and leadership skills are fundamental to create implementable solutions to pressing societal- and market-based global problems. The Research to Innovation to Society
(R2I2S) program is a transformative approach to graduate education, training students at the intersection of research, innovation, and leadership. We detail the design of the program,...
Air particulate matter (PM) samples were collected from June 2006 to May 2007 for determination chemical elements. PM samples were taken in two size fractions (PM₂.₅ and PM₁₀) with MiniVolume air samplers on rooftops of various buildings (15-25 m above ground) in the city of Riyadh. The samples were subjected...
This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by the American Chemical Society and can be found at: https://doi.org/10.1021/acs.est.5b00499
Propolis is a gummy material produced by honey bees to protect their hives and currently has drawn the attention of researchers due to its broad clinical use. It has been reported, based only on observations, that honey bees also collect other non-vegetation substances such as paint or asphalt/tar to make...
Sodium-ion batteries are emerging as a highly promising technology for large-scale energy storage applications. However, it remains a significant challenge to develop an anode with superior long-term cycling stability and high-rate capability. Here we demonstrate that the Na⁺ intercalation pseudocapacitance in TiO₂/graphene nanocomposites enables high-rate capability and long cycle life...
The heterogeneous reactions of ambient particulate matter (PM)-bound polycyclic aromatic hydrocarbons (PAHs) and nitro-PAHs (NPAHs) with NO₃/N₂O₅, OH radicals, and O₃ were studied in a laboratory photochemical chamber. Ambient PM[subscript 2.5] and PM₁₀ samples were collected from Beijing, China and Riverside, California, and exposed under simulated atmospheric long-range transport conditions...
Atmospheric measurements of semivolatile organic compounds (SOCs) were made at Mt. Bachelor Observatory (MBO), located in Oregon’s Cascade Range, to understand the trans-Pacific and regional transport of SOCs from urban areas. High volume air sampling (~644 m³ for 24 hour periods) of both the gas and particulate phases was conducted...
The regiodivergent O- to C- or N-carboxyl transfer of pyrazolyl carbonates is described, with DMAP giving preferential N-carboxylation and triazolinylidenes promoting selective C-carboxylation (both with up to >99 : 1 regioselectivity). An enantioselective O- to C-carboxyl variant using NHC catalysis is demonstrated (up to 92% ee), while mechanistic and DFT studies outline...
The synthesis of isoindazoles bearing α-ketoester and α-hydroxyester groups via the coarctate cyclization of ester terminated azo-ene-yne precursors is described. Whereas previous studies on isoindazole formation have shown the reaction to proceed through a kinetic coarctate pathway, functionalization of the terminal acetylene with a methyl ester sufficiently stabilizes the carbene...
Historic and current use pesticides (HUPs and CUPs), with respect to use in the United States and Canada, were identified in trans-Pacific and regional air masses at Mt. Bachelor Observatory (MBO), a remote high elevation mountain in Oregon’s Cascade Range located in the United States, during the sampling period of...
This chapter describes a mass spectrometry-based strategy that facilitates the unambiguous identification and characterization of proteins modified by lipid peroxidation-derived 2-alkenals. The approach employs a biotinylated hydroxyl amine derivative as an aldehyde/keto reactive probe in conjunction with selective enrichment and tandem mass spectrometric analysis. Methodological details are given for model...
This research is the first to quantify complex PAH mixtures in NIST SRMs using comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC/ToF-MS), with and without extract cleanup, and reports previously unidentified PAH isomers in the NIST SRMs. We tested a novel, high orthogonality GC column combination (LC-50×NSP-35), as...
After the April 2010 explosion on the Deepwater Horizon oil rig, and subsequent release of millions of barrels of oil, two Corexit oil dispersant formulations were used in unprecedented quantities both on the surface and sub-surface of the Gulf of Mexico. Although the dispersant formulations contain four classes of surfactants,...
The post-translational modification of proteins by electrophilic oxylipids is emerging as an important mechanism that contributes to the complexity of proteomes. Enzymatic and non-enzymatic oxidation of biological lipids results in the formation of chemically diverse electrophilic carbonyl compounds, such as 2-alkenals and 4-hydroxy alkenals, epoxides and eicosanoids with reactive cyclopentenone...
This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by Elsevier and can be found at: https://doi.org/10.1016/j.elspec.2012.12.004
We, for the first time, employ magnesiothermic reaction to convert microwave-irradiated graphite oxide to pure graphene. The magnesiothermic reaction raises the carbon to oxygen atomic ratio from 22.2 to 165.7 and maintains a high surface area. The new strategy demonstrates an efficient method for obtaining highly pure graphene materials.
This manuscript describes the role of non-classical hydrogen bonds (NCHBs), specifically C–H···O interactions, in modern synthetic organic transformations. Our goal is to point out the seminal examples where C–H···O interactions have been invoked as a key stereocontrolling element and to provide predictive value in recognizing future and/or potential C–H···O interactions...
The electrochemical intercalation of tetra-n-alkylammonium (TAA) cations into graphite is investigated using galvanostatic reduction and cyclic voltammetry in TAABr/ dimethylsulfoxide (DMSO) electrolytes. Structural and compositional analyzes by X-ray diffraction, thermogravimetric and elemental analyzes show that stable graphite intercalation compounds (GICs) are formed with highly-flattened TAA cation bilayers for (C₅H₁₁)₄N⁺, (C₆H₁₃)₄N⁺,...
We report an experimental and theoretical study of single-molecule inner-shell photoemission measured over an extended range of photon energies. The vibrational intensity ratios I (nu = 1)/I (nu = 0) from the C 1s photoelectron spectra of carbon monoxide, although mostly determined by the bond length change upon ionization, are...
We use femtosecond stimulated Raman spectroscopy (FSRS) to illuminate the choreography of intermolecular excited-state proton transfer (ESPT) of photoacid pyranine (8-hydroxypyrene-1,3,6-trisulfonic acid, HPTS) in water. The multidimensional reaction coordinate responsible for photoacidity is revealed to involve sequential activation of characteristic skeletal motions during the ca. 1 ps preparation stage preceding...
Carbon 1s photoelectron spectra for 2-butyne (CH3C CCH3) measured in the photon energy range from threshold to 150 eV above threshold show oscillations in the intensity ratio C2,3/C1,4. Similar oscillations have been seen in chloroethanes, where the effect has been attributed to EXAFS-type scattering from the substituent chlorine atoms. In...
Carbon 1s photoelectron asymmetry parameters β for the chlorinated and the methyl carbon atom of CH₃CH₂Cl, CH₃CHCl₂, and CH₃CCl₃ have been measured using synchrotron radiation in the 340-600 eV energy range. We provide experimental evidence that the intramolecular scattering strongly affects beta values, even far from the ionization threshold. The...
Oregon State University offers a wide range of online chemistry courses. The courses are well subscribed, as of 2013 approximately 13% of our department’s student credit hours were awarded in online courses, and both the online enrollment totals and the fraction of effort devoted to online instruction continue to increase....
The solid solution of In₂Fe₂₋ₓGaₓCuO₇ (space group P6₃/mmc) was synthesized and investigated through X-ray diffraction and magnetic susceptibility studies. Limited changes to the lattice parameters were observed as a result of the similar ionic radii for Fe³⁺ and Ga³⁺ in the trigonal bipyramidal (TBP) crystallographic site. An increase in the...
Abstract: Background: The cross section for forming a heavy evaporation residue in fusion reactions depends on the capture cross section, the fusion probability, P[subscript CN], i.e., the probability that the projectile-target system will evolve inside the fission saddle point to form a completely fused system rather than reseparating (quasifission), and...
Magnesiothermic reduction can directly convert SiO₂ into Si nanostructures. Despite intense efforts, efficient fabrication of highly nanoporous silicon by Mg still remains a significant challenge due to the exothermic reaction nature. By employing table salt (NaCl) as a heat scavenger for the magnesiothermic reduction, we demonstrate an effective route to...
We demonstrate the generation of broadband up-converted multicolor array (BUMA) in a thin BK7 glass slide using two noncollinear weak near-IR laser pulses with various crossing angles. The BUMA signal arises from cubic nonlinear χ⁽³⁾:χ⁽³⁾ processes via cascaded four-wave mixing of the two incident beams. Broad and continuous tunability of...
Hexagonal AMO₂ and AMO₃ phases have the same basic structure, and intermediate compositions for this structure have been prepared by topotactic oxidation of AMO₂ phases such as RCuO₂, where R is a trivalent rare earth cation. We now find that such intermediate phases can also be prepared by topotactic reduction...
Refractive indices of In₂O₃, In₂₋ₓSnₓO₃, InBO₃ and 2 different gahnite crystals (ZnAl₂O₄ and Zn.₉₅Fe.₀₅Al₂O₄) were measured at wavelengths of 435.8 to 643.8 nm and were used to calculate n at λ = 589.3 nm ( nD ) and at λ = ∞ (n∞) using the one-term Sellmeier equation 1/(n²-1) =...
Complete solid solutions with the composition Na₃M₂₋ₓM’ₓSbO₆ where M, M’ = Cu, Mg, Ni, Zn have been synthesized by conventional solid state techniques and were investigated using X-ray diffraction, magnetism and optical measurements. All compositions crystallize in a monoclinic unit cell and exhibit a layered structure with a honeycomb cationic...
We demonstrate the versatile broadband wavelength tunability of frequency upconverted multicolor cascaded fourwave-mixing (CFWM) signals spanning the continuous wavelength range from UV to near IR in a thin type-I BBO crystal using 35 fs, 800 nm fundamental and chirped IR supercontinuum white light pulses. Two sets of spatially dispersed CFWM...
The solid solutions of InGa₁₋ₓFeₓCuO₄, InFeCu₁₋ₓMgₓO₄, and InGa₁₋ₓFeₓCu₁₋ₓMgₓO₄ were
synthesized and characterized through the use of X – ray and neutron diffraction, and DC –
magnetism measurements. All compositions of InGa₁₋ₓFeₓCuO₄ are single phase and crystallize
in the R3m space group, but a transformation to the spinel InFeMgO₄ structure was...
Interstitially filled skutterudites are a promising class of state-of-the-art thermoelectric
materials. Although thermoelectrics are exposed to significant thermal stresses, little
information is known about the fracture toughness of interstitially doped skutterudites. This
work explores the fracture toughness of undoped Co₄Sb₁₂ and indium doped In₀.₁Co₄Sb₁₂
skutterudites using three methods: 1) Vickers...
Mapping out multidimensional potential energy surfaces has been a goal of
physical chemistry for decades in the quest to both predict and control chemical
reactivity. Recently a new spectroscopic approach called Femtosecond Stimulated Raman
Spectroscopy or FSRS was introduced that can structurally interrogate multiple
dimensions of a reactive potential energy...
We report zero kinetic energy (ZEKE) photoelectron spectroscopy via resonantly enhanced multiphoton ionization (REMPI) for benzo[e]pyrene. Extensive vibronic coupling between the first electronically excited state and a nearby state allows b₂ symmetric modes to be observed which would normally be Franck-Condon (FC) disallowed. These vibronic modes are comparable in intensity...
Organic aerosols are important atmospheric components, and their formation and sources represent important aspects of urban air quality and health effects. Asia, including India, is the largest global source of aerosol particles due to regional natural advection (e.g. desert and soil dust) and anthropogenic activities (e.g. emissions from traffic, industry...
The dipolar cylcoadditions of ortho-nitrophenyl alkynes with aryl nitrile oxides has been demonstrated. A range of substituents are tolerated on the alkyne. These reactions proceed with excellent levels of regioselectivity. Subsequent functionalization of the isoxazole scaffold has been demonstrated.
In this paper we present a novel fabrication technique that utilizes polycaprolactone (PCL) as bonding media due to its low melting temperature property. PCL is biodegradable polyester with a melting point of 60°C, and a glass transition temperature of -60°C [1-10]. It is employed as a rapid bonding technique in...
The potent antitumor agent phorboxazole A was synthesized from six subunits comprising C1-C2 (115), C3-C8 (98), C9-C19 (74), C20-C32 (52), C33-C41 (84) and C42-C46 (85). Tetrahydropyrans B and C containing cis-2,6-disubstitution were fabricated via palladium(II)-mediated intramolecular alkoxycarbonylation which, in the case of tetrahydropyran C, was carried out with catalytic palladium(II)...
We demonstrate the simultaneous generation of multicolor femtosecond laser pulses spanning the wavelength range from UV to near IR in a 0.1 mm Type I beta-barium borate crystal from 800 nm fundamental and weak IR super-continuum white light (SCWL) pulses. The multicolor broadband laser pulses observed are attributed to two...
n-Type In-filled CoSb₃ is a known skutterudite compound that has shown promising thermoelectric (TE) properties resulting in high dimensionless figure of merit values at elevated temperatures. Use in various waste heat recovery applications will require survival and operation after exposure to harsh thermal cycling environments. This research focused on uncovering...
Background: There is a long-term interest in running the fission reaction backward, i.e., studying the "inverse fission" of uranium. The recent availability of beams of n-rich fission fragments has stimulated interest in this endeavor.
Purpose: To search for inverse fission in the reactions Sn-¹²⁴,Sn-¹3² + Mo-¹⁰⁰.
Method: In the Sn-¹²⁴...
Fusion excitation functions for the reactions of Sn-¹²⁴,Sn-¹³² with Ca-⁴⁰,Ca-⁴⁸ were measured at energies near and below the Coulomb barrier. Weak sub-barrier fusion enhancement accounted for by coupling to the first 2(+) and 3(-) states in the target and projectile was observed for Sn-¹²⁴,Sn-¹³² + Ca-⁴⁸. However, the Sn-¹²⁴,Sn-¹³² +...
Discrete aqueous metal oxide polyionic clusters that include aluminum polycations, transition-metal polyoxometalates, and the actinyl peroxide clusters have captivated the interest of scientists in the realm of both their fundamental and applied chemistries. Yet the counterions for these polycations or polyanions are often ignored, even though they are imperative for...
This paper is a continuation of earlier work in which the high resolution infrared spectrum of [1.1.1]propellane was measured and its k and l structure resolved for the first time. Here we present results from an analysis of more than 16,000 transitions involving three fundamental bands v₁₀ (E' - A'₁),...
While the d⁰ transition-metal POMs of Group V (V⁵⁺, Nb⁵⁺, Ta⁵⁺) and Group VI (Mo⁶⁺, W⁶⁺) have been known for more than a century, the actinyl peroxide POMs, specifically those built of uranyl triperoxide or uranyl dihydroxidediperoxide polyhedra, were only realized within the last decade. While virtually every metal on...
High-resolution infrared absorption spectra have been analyzed for two bicyclo[111]pentane isotopologues, C₅H₈ (-d₀) and C₅H₇D (-d₁), where in the latter the D-atom replaces a hydrogen on the C₃ symmetry axis such that the molecular symmetry is reduced from D₃ₕ to C₃ᵥ. Two (a"₂) parallel bands, v₁₇ and v₁₈, of bicyclopentane-d₀...
Aqueous complexation of Th(IV), U(IV), Np(IV), Pu(III/IV), and Ce(III/IV) with DTPA was studied by potentiometry, absorption spectrophotometry, and cyclic voltammetry at 1 M ionic strength and 25 °C. The stability constants for the 1:1 complex of each trivalent and tetravalent metal were calculated. From the potentiometric data, we report stability...
The future of iron pnictide superconductors in technology is still undecided. While these materials are now known to possess high critical temperatures and critical magnetic fields processing methods for these materials are still in their infancy. Recently we have been investigating possible ways to speed up the synthetic process for...
The recent quest for improved functional materials like high permittivity dielectrics and/or
multiferroics has triggered an intense wave of research. Many materials have been checked for their
dielectric permittivity or their polarization state. In this report, we call for caution when samples are
simultaneously displaying an insulating behavior and a...
We report on the effects of spin fluctuations, magnetic ordering, and external magnetic field on the
dielectric constant of the ferromagnet SeCuO₃, and the antiferromagnet TeCuO₃. A model based on the
coupling between uniform polarization and the q-dependent spin-spin correlation function is presented
to explain the different behaviors for these...
Epitaxial LaRh₁/₂Mn₁/₂O₃ thin films have been grown on (001)-oriented LaAlO₃ and SrTiO₃ substrates using pulsed laser deposition. The optimized thin film samples are semiconducting and ferromagnetic with a Curie temperature close to 100 K, a coercive field of 1200 Oe, and a saturation magnetization of 1.7μB per formula unit. The...
The effect of quasi-hydrostatic pressure upon the ferromagnetic ground state of magnetodielectric, double-
perovskite La₂ MnNiO₆ is investigated using x-ray absorption spectroscopy and diffraction measurements in a
diamond anvil cell. The Mn-O-Ni superexchange interaction that gives rise to ferromagnetism in this cation-
ordered structure is stable to at least 38...
Filled skutterudites are promising thermoelectric materials due to reduced thermal
conductivity upon inserting a guest atom or 'rattler' into the CoSb₃ structure. By using an
indium rattler dimensionless Figure of Merit (ZT) values > 1 at 650 K have been reported.
The conventional synthesis of these compounds typically takes several...
This report details preliminary studies towards the development of a microfluidic sensor that exploits ferromagnetic resonance, excited in magnetic bead labels, for signal transduction. The device consists of a microwave circuit in which a slotline and a coplanar waveguide are integrated with a biochemically activated sensor area. The magnetic beads...
Myosins are actin-based molecular motors that may have specialized trafficking and contractile functions in cytoskeletal compartments that lack microtubules. The postsynaptic excitatory synapse is one such specialization, yet little is known about the spatial organization of myosin motor proteins in the mature brain. We used a proteomics approach to determine...