Seasonal variation in laboratory response to behavioral chemicals of the southern pine beetle

The response ofDendroctonus frontalis to an attractant mixture (frontalin,trans-verbenol, and loblolly pine turpentine) was measured in the laboratory over a four-year period. Beetle response was highest in late winter and early spring, and lowest in midsummer and early fall. Males consistently responded higher than females. Female beetles displayed significantly higher responses in early morning and late afternoon than in the middle of the day. Analysis of beetle pronotal width and fat content revealed a high degree of correlation between these two parameters in female beetles, but there was no correlation of response with either fat content or pronotal width for either sex. There was no evident relationship between mean monthly beetle response and total amounts of frontalin andtrans-veibenol found in hindgut extracts. Daily temperature in months both during which beetles were bioassayed and immediately prior to bioassay was highly correlated to response to the attractant.Texas Agricultural Experiment Station Paper Number 16652. This research was supported by McIntire-Stennis Project 1525, and the U.S. Department of Agriculture-sponsored program entitled The Expanded Southern Pine Beetle Research and Applications Program through TAES-SEA-CR Grant 904-15-4. The findings, opinions, and recommendations expressed herein are those of the authors and not necessarily those of the U.S. Department of Agriculture. All programs and information of the Texas Agricultural Experiment Station are available to everyone without regard to race, color, religion, sex, age, or national origin.     

Reactions of co-adsorbed carbon dioxide and dioxygen at the Mg(0001) surface at low temperatures

X-ray photoelectron spectroscopy has established that molecular dioxygen states are stabilised at a Mg(0001) surface in the presence of physisorbed carbon dioxide at 80 K. The dioxygen–CO₂ complex is highly reactive with low energy reaction pathways to carbonate formation; the latter is subsequently reduced to give surface carbide and oxide at a temperature below 150 K. This revised version was published online in June 2006 with corrections to the Cover Date.     

Chemical reactivity of CO and CO2 at a Cu(110)-Cs surface

Carbon dioxide and carbon monoxide undergo reactive chemisorption with cesium modified Cu(110) and Cu(110)-O surfaces and via the anionic intermediate CO ₂ ^– (a) form a surface carbonate. The CO ₂ ^– (a) species was characterised by VEELS and XPS at low temperature (80 K) and the surface carbonate at 295 K. For cesium modified Cu(110) surfaces chemisorption of carbon monoxide gives rise to electron energy loss peaks (v _co) as low as 1450 cm^–1 at 295 K.     

Joining carbon nanotubes

To fully exploit the exceptional electronic and mechanical properties of carbon nanotubes in real-world applications, it is desirable to create carbon nanotube networks in which separate, multiple nanotubes are joined so that as many as possible of the properties of single nanotubes are conserved. In this review we summarize the progress made towards this goal, covering techniques including electron and ion beam irradiation, Joule heating and spark plasma sintering.     

Stress grading for high voltage motor and generator coils

Stress grading on high voltage motor and generator stator windings is becoming more important as the electrical stress in the ground insulation is increased. While there are a variety of possible ways to relieve surface stress, non-linear resistive tapes have been almost universally adopted because of their simplicity and efficiency. However, selection and quality control on these materials has been problematic, as the means to characterize these materials has not been clearly set out. Most types of material can be characterized in terms of two parameters, a threshold stress and a gradient index, which can be determined from simple current and voltage measurements. It is hoped, therefore, that manufactures of grading products will adopt such measurements and publish these values as a matter of course. This will enable coil manufacturers to improve the specification and quality control of stress grading coatings     

Porous composites of hydroxyapatite‐filled poly[ethylene‐co‐(vinyl acetate)] for tissue engineering

A novel porous composite of hydroxyapatite/poly[ethylene‐co‐vinyl acetate)] (HAP/EVA) having better osteointegration was fabricated by gas foaming technique using a non toxic gas blowing agent intended for bone replacement applications. Combined techniques of scanning electronic microscopy (SEM) and X‐ray microcomputed tomography (µCT) analysis showed that the pore size and pore volume of the porous composite decrease with the increase of HAP content. The gravimetric analysis evidenced for good pore interconnectivity within the porous composites. Energy dispersive X‐ray analysis (EDX) studies inveterated the even scattering of Ca ions which in turn indicate the uniform dispersion of HAP particles in the composites. The significant gradation in Ca ion concentration seen in EDX studies is well accordance with the amount of HAP loading in the sample. Mechanical properties of the porous composite having different HAP content were measured to have the compressive strength varying from 1.06 to 2.2 MPa. Non‐cytotoxic character of the material was observed by the cytocompatibility studies. The metabolic activity of L929 cells seeded on the material assessed by [3‐(4,5‐dimethylthiazol)‐2‐yl]‐2,5‐diphenyltertrazolium bromide (MTT) assay was found to be 91.8%. The adhesion and migration of the cells inside the pore walls were visualized by confocal microscopy. Copyright © 2010 Society of Chemical Industry     

Stereological estimation of the total volume of MR visible brain lesions in patients with multiple sclerosis

Point counting represents a convenient and efficient technique for estimating the area of transects through multiple sclerosis (MS) lesions on magnetic resonance (MR) images obtained for sections through the brain. When sectioning has been performed according to the Cavalieri method, unbiased estimates of the total volume of MR-visible MS plaques can be obtained with a precision of 3–5% in 5–10 min.     

The Vitrifix process

The Vitrifix process solves the problems of nonbiodegradability and the legal liability for asbestos in a landfill by totally destroying the asbestos and converting it into a safe, useful product-glass. The process uses well-established glass technology in a unique fashion. The use of an existing technology gives great reliability, and the way it is applied makes the process intrinsically safe. The successful demonstration of the process to the US Environmental Protection Agency and its commercial operation in the UK are described. Comprehensive testing of the glass product using transmission electron microscopy and X-ray diffraction confirmed that the product is totally amorphous glass. No trace of asbestos or any crystalline structure was detected     

Shear-induced migration and axial development of particles in channel flows of non-Brownian suspensions

We present an experimental study on the shear-induced migration and axial development of particles in the channel flows of non-Brownian suspensions. The suspending fluid is Newtonian. We investigate fracturing flows with a Hele-Shaw type scaling through building a unique channel setup and an advanced optical system. The local particle concentration profiles are measured via the refractive-index matching technique for a wide range of bulk volume fraction, that is, . Simultaneously, the particle image velocimetry is performed to determine the velocity profile of the particle phase. We compare our experimental results with the available two-phase continuum frameworks and show discrepancies and similarities in the fully developed and axial development of the solid volume fraction profiles. We discuss directions in which the continuum frameworks require improvements.