Ion-Molecule Reactions in Unsaturated Hydrocarbons: Allene, Propyne, Diacetylene, and Vinylacetylene

Ion-molecule reactions in allene, propyne, diacetylene, and vinylacetylene (1-buten-3-yne) have been studied at near-thermal energies by the technique of ion cyclotron resonance mass spectrometry. Rate coefficients and branching ratios are reported for the reactions of C_3H^+_n (n = 1-4) with allene and propyne and for the reactions of C_4H^+_n (n = 0-5) with diacetylene and vinylacetylene. Branching ratios are also given for the reactions of C_4H^+_n, C_5H_n, and C_6H^+_n with propyne and for reactions of C_6H^+_n with diacetylene and vinylacetylene. More than 90% of the reactive channels lead to product ions having a larger carbon skeleton than the reactant ion. Evidence for ions with the same m/e ratio having differing reactivities was obtained for C_3H^+_3, C_6H^+_7, and C_7H^+_7. Ion reaction sequences in allene and propyne were followed at higher pressures (l0^(-4) torr) to investigate secondary, tertiary, and higher order processes

Teleportation of entangled states without Bell-state measurement

In a recent paper [Phys. Rev. A 70, 025803 (2004)] we presented a scheme to teleport an entanglement of zero- and one-photon states from a bimodal cavity to another one, with 100% success probability. Here, inspired on recent results in the literature, we have modified our previous proposal to teleport the same entangled state without using Bell-state measurements. For comparison, the time spent, the fidelity, and the success probability for this teleportation are considered.Comment: 4 pages, 1 figure, published in Phys. Rev. A 72, 045802 (2005

Effects of Polychlorinated Biphenyl Compounds and Proposed PCB-Replacement Products on Embryo-Larval Stages of Fish and Amphibians

Static renewal bioassays were performed with four polychlorinated biphenyls, including Capacitor 21 and Aroclors 1016, 1242, and 1254. Each compound was used to treat embryo-larval stages of the rainbow trout (Salmo gairdneri), channel catfish (Ictalurus punctatus), goldfish (Carassius auratus), redear sunfish (Lepomis microlophus), leopard frog (Rana pipiens), Fowler\u27s toad (Bufo fowleri), and American toad (Bufo americanus). Developmental stages of the trout were the most sensitive, with LC50 \u27s at 4 days posthatching of 0.3, 1.0, 1.1, and 1.6 μg/l for Aroclors 1254, 1242, 1016, and Capacitor 21, respectively. LC1\u27s ranged between 0.009-0.011 μg/l. Fowler\u27s toad was the most tolerant species, and LC50 \u27s varied from 3.7-28.0 μg/l. Toxicity of the PCB\u27s generally increased with percent chlorine substitution. Bioassays also were conducted with dioctylphthalate (D0P), diisononylphthalate, and Dow Corning 561 silicone, three products proposed as replacements for PCB\u27s. Embryos and larvae of the channel catfish, redear sunfish, leopard frog, and Fowler\u27s toad were exposed through 4 days posthatching. Catfish was the most sensitive species, and sunfish was the most resistant. Based on LC50 values, replacement products were found to be 2-5 orders of magnitude less toxic than PCB\u27s. Continuous flow embryo-larval bioassays were performed on Capacitor 21 and DOP. Test species included redear sunfish, rainbow trout, and largemouth bass (Micropterus salmoides). Paralleling results from static renewal tests, flow-through data reflected a vast difference in toxicity between PCB\u27s and potential replacements, and good data correlation was achieved between the two bioassay procedures

Anti-symmetric rank-2 Matter Field on Superspace for N_{T}=2

In this work, we discuss the interaction between anti-symmetric rank-two tensor matter and topological Yang-Mills fields. The matter field considered here is the rank-2 Avdeev-Chizhov tensor matter field in a suitably extended $N_{T}=2$ SUSY. We start off from the $N_{T}=2$, D=4 superspace formulation and we go over to Riemannian manifolds. The matter field is coupled to the topological Yang-Mills field. We show that both actions are obtained as $Q-$exact forms, which allows us to write the energy-momentum tensor as $Q-$exact observables.Comment: 10 pages, no figure, LaTe

Sensitivity of Vertebrate Embryos to Heavy Metals as a Criterion of Water Quality: Phase III: Use of Fish and Amphibian Eggs as Bioindicator Organisms for Evaluating Water Quality

Fish and amphibian eggs, embryos and early posthatched (larval) stages were evaluated as bioindicator organisms with which to monitor the quality of natural water resources. Eggs of 9 species were cultured in water collected from each of 11 Inner Bluegrass rivers and streams. The latter were chosen to represent water sources varying in quality from extremely poor to good. Selection was based on the sources and magnitude of pollution, and the diversity and density of piscine populations. Cultures were maintained in vitro, using 12-hour changes of water. Averaging data for all 9 animal species, egg hatchability (embryonic survival) ranged from 0% for the most contaminated water to 94% for uncontaminated water found to support a healthy aquatic biota. Eggs of the squirrel treefrog and gray treefrog were the most sensitive of 5 amphibian species tested, and of 4 fish species, rainbow trout eggs proved most susceptible to water contaminants

Liquid or Dry Nitrogen

Pound for pound of actual nutrients, liquid or dry sources of nitrogen are about the same, and choice depends largely on cost. This article is the first of two dealing with the relative costs of using either

What Cost for Liquid or Dry Nitrogen?

Beyond personal preference and convenience, choice of liquid or solid sources of nitrogen depends mainly on the costs of materials, or application itself and of any application and storage equipment necessary

Clastic Sinkhole and Pseudokarst Development in East Texas

Pseudokarst development in East Texas is controlled primarily by a combination of suffosion and preferential flow paths, often creating small ephemeral sinkholes but occasionally persistent features develop in more indurated facies. Pseudokarst occurs in Claiborne (Eocene) strata in Angelina, Cherokee, Nacogdoches, Panola, Rusk, San Augustine and Shelby counties. Strata consist of interbedded fine- and coarse-grained clastics with variable cementation and associated permeabilities