Resin Plugs Research Articles

Damage-tolerant, laminated structural supercapacitor composites enabled by integration of carbon nanotube fibres

A natural embodiment for multifunctional materials combining energy-storing capabilities and structural mechanical properties are layered structures, similar to both laminate structural composites and electrochemical energy-storage devices. A structural composite with integrated electric double layer capacitive storage is produced by resin infusion of a lay up including woven glass fabric used as mechanical reinforcement, carbon nanotube non-woven fabrics as electrodes/current collectors and a polymer electrolyte. The energy-storing layer is patterned with holes, which after integration form resin plugs for mechanical interconnection between layers, similar to rivets. Finite element modelling is used to optimise rivet shape and areal density on interlaminar shear properties. Galvanostatic charge-discharge tests during three-point bending show no degradation of properties after large deflections or repeated load/unload cycling at 3.5 V. This mechanical tolerance is a consequence of the elimination of metallic current collectors and the effective integration of multifunctional materials, as observed by electron microscopy and x-ray computed tomography. In contrast, control samples with metallic current collectors, analogous to embedded devices, rapidly degrade upon repeated bending.

Silicified logs of Agathoxylon hoodii (Tidwell et Medlyn) comb. nov. from Rainbow Draw, near Dinosaur National Monument, Uintah County, Utah, USA, and their implications for araucariaceous conifer forests in the Upper Jurassic Morrison Formation

A new local flora of silicified logs and wood has been discovered in the Upper Jurassic Morrison Formation in the Rainbow Draw area near Dinosaur National Monument, northeastern Utah, USA. Fossil logs and wood were found in the Salt Wash Member at nine sites at Rainbow Draw and at one site near Miners Draw, south of Blue Mountain. The fossil logs are large and relatively intact, the longest measuring 11 m. The wood is well preserved, coniferous, and can be identified to the species level. Diagnostic anatomical features include resin plugs in the ray cells and axial tracheids, araucarioid tracheary pitting and crossfield pitting, and the lack of resin canals and true, regularly occurring growth rings. This taxon of fossil wood, originally described as Araucarioxylon hoodii Tidwell et Medlyn, is recognized here as a new combination, Agathoxylon hoodii (Tidwell et Medlyn) Gee, Sprinkel, Bennis et Gray, which pertains to the conifer family Araucariaceae. Based on the preserved girth of the logs, the minimum height of the trees could be reconstructed. The largest fossil logs measured at least 127 cm in diameter and hence reached a minimum height of 28 m. Judging from the growth habit of all naturally occurring araucariaceous trees today, the fossil plants likely formed forests of moderately tall trees and were well over 100 years old. The lack of true growth rings shows that there was no seasonality in the local paleoclimate, neither variations in summer–winter temperatures, nor wet–dry cycles. Thus, during the Late Jurassic, tall conifer forests with Agathoxylon hoodii grew in at least two areas in what is now Utah: east of the city of Vernal and near Mt. Ellen in the Henry Mountains. Coupled with the fossil evidence of conifer seed cones and pollen found in the Morrison Formation throughout eastern Utah, the newly discovered fossil logs and wood argue for the reconstruction of Upper Jurassic habitats in this region as mesic and wooded, and the climate as equable, not seasonal, nor semi-arid or arid.

A NEW RECORD OF AGATHOXYLON FROM THE OLIGOCENE-MIOCENE OF SOUTH CHINA

A gymnosperm wood is described from the Oligocene-Miocene of Hainan Island, South China. It is characterized by circular, thin-walled tracheids with resin plugs, 1–3-seriate alternate or opposite intertracheary pits in radial walls, 1–2-seriate rays, cross fields with 3–14 araucarioid cross-field pits. These are features found in the Araucariaceae and the fossil is designated as Agathoxylon sp. Fossil woods with anatomical characteristics seen in the Araucariaceae are extremely rare in the North Hemisphere after the K/T boundary. Thus, this Agathoxylon from the Oligocene-Miocene of South China has significance for biogeographic studies.

Gas/particle partitioning of currently used pesticides in the atmosphere of Strasbourg (France)

Atmospheric particle (P) and gas (G) phase samples have been collected in Strasbourg (Northeast of France) using a high-volume sampler equipped with a filter-XAD-2 resin plug between April 17 and May 29, 2007. Seventy-one currently used pesticides were monitored in these samples, and 38 of them were detected at concentrations ranging from 0.07 ng/m3 for fenarimol to 40.30 ng/m3 for deltamethrin in the particle phase and from 0.03 ng/m3 for fenarimol to 89.54 ng/m3 for dimethachlor in the gas phase. These results were used to study the G/P partitioning of the pesticides using Junge-Pankow-based models, and to evaluate the influence of environmental parameters (temperature and humidity) on this partitioning. The average slope of log KP against log \( P_{\rm{L}}^0 \) was −2.11, suggesting that partitioning is influenced by adsorption. The partitioning equations also showed that the atmospheric concentrations of the monitored pesticides were dominated by volatilisations from local sources. Concerning environmental parameters, temperature was found to strongly influence the G/P partitioning of the studied pesticides while humidity has only very little influence on it.

Gas/particle partitioning of lindane and current-used pesticides and their relationship with temperature in urban and rural air in Alsace region (east of France)

The understandings of atmospheric transport of pesticides need the knowledge of pesticides vapour/particles distribution. Different parameters can influence this equilibrium: total suspended particles (TSP), ambient temperature… vapour/particles (V/P) partitioning of PAHs, OCs and PCBs are well documented. Because of their long life-time, most of the OCs are now prohibited in Europe. They are now replaced by new compounds for which few data are available. In this work it is reported that the influence of TSP, relative humidity of and ambient temperature on the V/P partitioning of different current-used pesticides commonly applied in Alsace region. For this study, a filter-XAD-2 resin plug high-volume air sampler was used to collect simultaneously the particle (P) and vapour (V) phases of pesticides simultaneously on three sites (urban, rural and remote). It can be observed that the cited parameters did not influence individually the V/P partitioning of the studied pesticides. This observation shows that the V/P partitioning is the result of the combined influence of all of the parameters. For all of the pesticides, the vapour phase concentration increases with the decrease of the particle concentration and of the temperature. The influence of the temperature was monitored by the use of the Clausius–Clapeyron equation. From this study, it can be shown that the distribution of alachlor in the gas phase was of local origin while for trifluralin and lindane, results indicate the contribution of long-range transport processes on their gas phase distribution.

A demountable nonmagnetic multiconductor feedthrough suitable for use in liquid helium applications

A superfluid-helium-tight nonmagnetic electrical feedthrough has been developed by using brass pins embedded within an epoxy resin plug and mounted on a beryllium copper Conflat flange. A method for building these feedthroughs is discussed, and their performance history is described.

Entangled Palladium Nanoparticles in Resin Plugs

Palladium nanoparticles were generated and immobilized inside resin beads, which were sintered and embedded in high-density polyethylene-based modular cylindrical plugs (resin plugs). Thus, the resin plugs bearing a 4-(amino­methyl)phenyl group were treated with Pd(OAc)2 to give Pd2+-loaded resin plugs. Palladium nanoparticles were generated in the resin plugs via reduction with hydrazine. The aminomethyl groups were entangled with succinyl chloride to give cross-linked palladium nanoparticle plugs (XL-Pd). The catalytic ability of the XL-Pd was examined for Suzuki, Sonogashira, and Heck coupling of aryl halides. Representative results are summarized in the scheme.

Study of the effects of environmental parameters on the gas/particle partitioning of current-use pesticides in urban air

A filter-XAD-2 resin plug high-volume air sampler was used to collect particulate (P) and gaseous (G) phases of seven pesticides (atrazine, terbuthylazine, alachlor, metolachlor, cymoxanil, diflufenicanil, and fenoxaprop- p-ethyl) and two metabolites (de-ethylatrazine (DEA) and de-ethylterbuthylazine (DET)) in downtown Strasbourg (France). Most of the molecules listed above were found to be associated only with particulate aerosols and only four of them were detected regularly in both atmospheric phases (particulate and gaseous). The results presented in this work showed that models developed previously to describe the gas/particle (G/P) partitioning did not work for currently used pesticides. A new partition equation ( K org, m 3 ng −1) was defined for the pesticides under study using environmental parameters such as temperature, relative humidity, and organic carbon content of atmospheric aerosols.

Entangled palladium nanoparticles in resin plugs

Palladium nanoparticles were entrapped within resin plugs and used in a range of ligand-free cross-coupling reactions; the convenient modular format of the resin plug enhanced resin handling and allowed the catalysts to be easily recovered and multiply reused.

Reusable Resin Plug‐Bound Palladium Catalysts for Organic Synthesis.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Reusable resin plug-bound palladium catalysts for organic synthesis

Resin plugs, a unique and conveniently handled form of resin, prepared by sintering high-density polyethylene (HDPE) with pre-functionalised resins, were derivatised and loaded with palladium(0). These ‘plugs’ were used in the preparation of a Suzuki reaction based library and the removal of allyl ester protecting groups. The ‘plugs of catalyst’ were easily separated from the reaction mixture and were re-used multiple times with minimal loss of activity.

Formats for Combinatorial Synthesis: Solid‐Phase, Liquid‐Phase and Surface

AbstractFor Abstract see ChemInform Abstract in Full Text.

The Encore Technique: A Novel Approach to Directed Split-and-Pool Combinatorial Synthesis

Publisher Summary This chapter discusses the Encore technique that is useful for the directed split-and-pool combinatorial synthesis. The Encore method is based on one-dimensional spatial encoding of the synthesis chemical history, referred to as necklace coding, and applied for the synthesis on SynPhase Crowns and Lanterns. The Encore technique combines three different coding methods: (1) sequential position on a necklace for the first combinatorial step, (2) color coding of individual necklaces for the second combinatorial step, and (3) reaction vessel coding to identify the last building block. The Encore synthesizer represents a simple and efficient personal chemistry tool that allows the execution of directed split-and-pool combinatorial synthesis. The current version of the Encore synthesizer is designed for solid-phase synthesis on SynPhase Lanterns; however, it can be modified for the synthesis on alternative solid supports such as resin plugs from Polymer Laboratories (like StratoSpheres Plugs). The split-and-pool synthesis not only simplifies the complexity of the combinatorial synthetic process, but also offers additional important benefits. Parallel synthesis of a thousand compounds requires handling of a thousand reaction vessels. The timely addition of sensitive reagents at low temperature (–78°C) under inert atmosphere during parallel synthesis is not a trivial task. It can be done if sophisticated automated synthesizer equipment is designed to handle and tolerate such reaction conditions. Such a synthesis can alternatively be performed easily in a manual fashion using a split-and-pool method that requires only a limited number of reaction vessels.

WOOD ANATOMY OF WOLLEMI PINE (WOLLEMIA NOBILIS, ARAUCARIACEAE)

The wood anatomy of the recently-discovered conifer Wollemia nobilis (Wollemi pine) is described for the first time. Its mature heartwood is light brown in colour and has an air dry density of 0.57 g /cm3. Growth ring boundaries are distinct and the transition from earlywood to latewood is gradual. Average tracheid length is ~ 3.4 mm. Bordered pits are one-, two- or three-seriate and the double and triple rows of pits are ‘alternate’. In the bordered pits there is a flat transition from torus to margo. A warty layer lines tracheid walls and pit cavity surfaces. Resin plugs are common in tracheids that are adjacent to rays. Helical thickenings and crassulae are absent. Rays are uniseriate, low, and are composed entirely of parenchyma cells whose walls are thin and unpitted. Cross-field pitting is ‘araucaroid’ and the number of pits per cross-field ranges from 3–11 (av. 7). Resin canals and axial parenchyma cells are absent. The differences between normal mature wood compared to compression and juvenile wood are consistent with those of most other conifer genera. The anatomical features of wood of W. nobilis strongly support its classification as a member of the Araucariaceae, but show no major differences that distinguish it as a monotypic genus. On the basis of its wood anatomy, it is not possible to state whether W. nobilis is more closely related to Agathis or to Araucaria.

Gas–particle partitioning of pesticides in atmospheric samples

A filter-XAD-2 resin plug high-volume air sampler was used to collect the particle (P) and vapour (V) phases of 11 pesticides. The atmospheric concentrations were measured simultaneously at three sites characterised as remote (Aubure in the Vosges mountains), rural (Colmar, in the upper Rhine Valley), and urban (Strasbourg, in the upper Rhine Valley). The measured concentrations, which agree with those of literature, were used to study the influence of the physico–chemical parameters on the V/P partitioning. The behaviour observed on two organochlorine pesticides ( α-HCH and HCB), carbaryl, and trifluraline corresponds to the one presented in literature for organochlorine and PAH. Therefore, the V/P partitioning is mainly controlled by temperature, total suspended particle (TSP), and vapour pressure. Nevertheless, the slope of the regression line of log( A.TSP/ F ) against log P° l (where A and F are, respectively, the gas and particulate concentrations and P° l is the subcooled liquid–vapour pressure) is less compared with that presented in literature (0.36 against approximately 0.85). This difference could possibly result from the low TSP concentrations measured in our study. For some pesticides (trifluraline, γ-HCH, mecoprop, carbofuran and atrazine) the description of the V/P partitioning is improved by using relative humidity in addition to the three previous environmental parameters (temperature, TSP and vapour pressure). There seems to exist a competition mechanism between water molecules in gas phase and pesticides to adsorb on the receiving sites of the particles. By this mechanism increase in the atmospheric relative humidity induces a simultaneous increase of pesticides in the gas phase.

Structural Evidence of a Sealed Tissue Interface with a Total-etch Wet-bonding Technique in vivo

The resin-dentin interface of in vivo specimens restored with the All-Bond 2 system by use of a total-etch wet-bonding technique on vital deep human dentin was investigated by: (a) SEM examination of cryofractured specimens; (b) SEM examination of acid-rinsed, highly polished, embedded specimens; and (c) TEM examination of demineralized ultrathin sections. Ultrastructural features that were pertinent to the formation of an effective clinical seal were characterized. It is suggested that the establishment of an effective seal of the patent dentinal tubules following total etching is accomplished by: (1) the formation of an outer zone of a solid resin plug surrounded by a circumferential cuff of resin-impregnated dentin; and (2) the formation of an inner zone of a hollow resin sheath with resin globules along the internal walls of the tubules, closely adapting to the odontoblast process. The structural appearance and functional implications of these two zones were strikingly similar, with the sealing of exposed dentinal tubules in arrested carious lesions or cervical abfraction lesions. It appeared that there is a common denominator in physiologic isolation defense mechanisms and the total-etch, wet-bonding technique in the All-Bond 2 system in preserving the biological and morphological integrity of the pulpo-dentinal complex.

Work-Related Toxic Epidermal Necrolysis?

A case of toxic epidermal necrolysis is described in an employee of a company that carries out plastic extrusion using various resins, including cellulose acetate, co-polyester, polyvinyl chloride, acrylonitrile-butadienestyrene, and polyethylene. Air sampling during normal operating conditions indicated only trace amounts of hydrogen chloride and the plasticizer diethylphthalate. However, pyrolysis products of resin plugs could include compounds such as formaldehyde, acrylonitrile, and chlorinated hydrocarbons that have been associated with previous case reports of either erythema multiforme, Stevens-Johnson syndrome, or toxic epidermal necrolysis. The development of toxic epidermal necrolysis in this worker was directly preceded by exposure to a vapor from a machine used to dry cellulose acetate. The problems in determining work relatedness and advising about return to work are discussed.

Preparation of Unconsolidated Sands for Microscopy Laboratory Exercises

Microscopic examination of unconsolidated sands and coarse silts usually receives minimal attention in various sedimentology courses because of the difficulty of preparing adequate slides for study. Our technique for overcoming part of this problem is to impregnate small amounts of sandy sediment with a quick-curing resin. Once the sediment- resin plug is removed from a mold, it can be polished quickly for standard low magnification binocular (reflected light) microscopic studies. Using these easily made preparations, laboratory exercises with unconsolidated sands can be conducted efficiently for the determination of mineral composition, provenance, and grain roundness and sphericity in a manner that is comparable to the study of indurated sandstones in thin sections.

Effects of End Plugs on Electric Input Power for Theta Pinch Plasmas

Theta pinch plasmas plugged with a metal and with an insulator were studied experimentally. Both the externally-supplied input power and the electric heating power were measured by a magnetic probe and a magnetic loop. In addition, the spectral line intensity was measured in order to investigate the effects of the plugs on ionization phenomena in the plugged plasmas. The end plugs had a significant effect on the profiles of the electromagnetic field, the electric heating power and the spectral intensity. It was also found that an acrylic acid resin plug was effective for heating the pinch plasma in the compression phase and that an aluminium plug was useful for maintaining the ionized state for a long time during the decay phase.

Physicochemical investigation of a cation exchange resin (amberlite IR100) II. Resin conductance

1. 1. The electric conductivity of swollen resin plugs packed between perforated platinum electrodes, and containing various bound cations, is investigated in a special streaming cell, which allows of replacement of one ionic species by another in the same plug. This method proves to be a useful tool in the investigation of the strength of binding of cations in the resin. 2. 2. The hydrogen resin is a fairly good conductor; the conductance of alkali metal resins is about 6–12 times smaller, while resins in which hydrogen is replaced by ions of higher valency, or silver, are poor conductors. For hydrogen and alkali metal resins, the resin conductance is roughly proportional to the mobility of the respective cations in water, but no such proportionality exists for resins containing silver or ions of higher valency. It is concluded that the latter are much more tightly bound than the former, the order being Th 4+>La 3+>>Ba ++>Ag +>Ca ++>>Mg ++>>alkali metal ions > H + 3. 3. The variation of the resistance of plugs of alkali metal resins with the pH of the salt solution used in the exchange reaction is studied. The resistance has a maximum at pH ⋍ 3.5 but falls when the pH of the salt solution is higher. It is suggested that up to pH ⋍ 3.5 the -SO 3H groups are involved, but that groups of a more weakly acid nature come into action at higher pH. There is evidence of hydrolysis of alkali metal salts of the latter groups on streaming water through the resin plug.