In-Situ Measurement of Dimensional Changes During Supercritical Fluid Impregnation of White Spruce Lumber

Supercritical fluids can markedly enhance preservative treatment of wood, but the high pressures employed can lead to collapse. We investigated the effects of the rates of pressure application and release or, displacement of white spruce lumber during supercritical impregnation with carbon dioxide. Displacement was greatest when pressure was rapidly increased at the start of the process. Conversely, rapid pressure release at the conclusion of the treatment process resulted in the lowest level of permanent displacement. The results suggest that wood displacement during supercritical fluid impregnation can be controlled by altering process variables for a given species

Response surface methodology models of processing parameters for high performance phenolic compreg wood

The aim of the study was to develop response surface methodology (RSM) models for polymer loading, density, dimensional stability, strength and stiffness of compressed wood of sesenduk (Endospermum diadenum) treated with phenol formaldehyde (PF). Central composite design (CCD) using RSM with three processing parameters was studied in their specific ranges: PF concentration (PC) from 24-40%, pre-curing time (PCT), 3-9 h and compression ratio (CR), 70-90%. The experimental design was analysed and interpreted using the Design Expert Software (Stat Ease version 8) and the responses of 3d plots were built using the same software. Quadratic models in terms of PC, PCT and CR were developed for polymer loading, density, reduction in water absorption and modulus of rupture in static bending. Multiple linear equations were developed for anti-swelling efficiency and modulus of elasticity. The experimental values were in good agreement with predicted ones and the models were highly significant with correlation coefficients between 0.626 and 0.926. PC and CR had significant effects on the responses. The range of PCT used did not significantly affect the responses. It was also found that the improvement of properties ranged from moderately to highly correlated with the polymer loading in the compreg wood

Removal of Particulate Matter in a Tubular Wet Electrostatic Precipitator Using a Water Collection Electrode

As one of the effective control devices of air pollutants, the wet electrostatic precipitator (ESP) is an effective technique to eliminate acid mist and fine particles that are re-entrained in a collection electrode. However, its collection efficiency can deteriorate, as its operation is subject to water-induced corrosion of the collection electrode. To overcome this drawback, we modified the wet ESP system with the installation of a PVC dust precipitator wherein water is supplied as a replacement of the collection electrode. With this modification, we were able to construct a compact wet ESP with a small specific collection area (SCA, 0.83 m2/(m3/min)) that can acquire a high collection efficiency of fine particles (99.7%)

Natural durability of some hardwoods imported into korea for deck boards against decay fungi and subterranean termite in accelerated laboratory tests

This study evaluated the natural durability of seven imported hardwoods (bangkirai, burckella, ipe, jarrah, kempas, malas, and merbau) used for deck boards against decay fungi (Fomitopsis palustris, Gloeophyllum trabeum, Trametes versicolor, and Irpex lacteus) and the subterranean termite (Reticulitermes speratus kyushuensis) in accelerated laboratory tests. Ipe, jarrah, and merbau were very durable to fungal attack, with performance comparable to ACQ-treated wood. Bangkirai, burckella, kempas, and malas were classified as durable or moderately durable, depending on the fungal species tested. All wood species except for merbau were highly resistant to termite attack. Termite resistance was similar to ACQ-treated wood. Merbau showed somewhat less than all other species but still significant termite resistance. These results indicated that selected naturally durable hardwood species could inhibit fungal and termite attacks as effectively as ACQ treatment. The natural durability of wood species tested in this study is most likely due to the biocidal extractive content of the wood

In-situ measurement of dimensional changes during supercritical fluid impregnation of white spruce lumber

Supercritical fluids can markedly enhance preservative treatment of wood, but the high pressures employed can lead to collapse. We investigated the effects of the rates of pressure application and release on displacement of white spruce lumber during supercritical impregnation with carbon dioxide. Displacement was greatest when pressure was rapidly increased at the start of the process. Conversely, rapid pressure release at the conclusion of the treatment process resulted in the lowest level of permanent displacement. The results suggest that wood displacement during supercritical fluid impregnation can be controlled by altering process variables for a given species.Keywords: pressure, collapse, supercritical fluids, spruce, displacemen

Ecotoxicity of heat-treated Kapur and Japanese larch

Kapur (Dryobalanops sp.) and Japanese larch (Larix kaempferi) wood samples were heat-treated in air at 180 °C for 24 and 48 h. Leaching and toxicity tests were conducted to determine the ecotoxicity effect of these heat-treated woods on the aquatic environment due to heat treatment. The toxicity of conventional preservative-treated woods, i.e. chromated copper arsenate (CCA) and ammoniacal copper quat (ACQ), was also determined for comparison purposes. Acute toxicity tests were performed using two aquatic organisms, Daphnia magna and Vibrio fischeri according to the Organization for Economic Co-operation and Development standard procedures and Microtox assay, respectively. Significantly low toxicity to D. magna was found for the heat-treated Kapur compared to that of untreated Kapur, while heat-treated Japanese larch did not show any toxicity effect. As expected, ACQ-treated samples showed the highest toxicity to D. magna, followed by that of CCA, though toxicity of both preservative-treated woods further reduced over time. Hence, heat treatment of Kapur and Japanese larch were believed to be not harmful to the aquatic ecosystem

Effect of Microstructural Constituents on Hydrogen Embrittlement Resistance of API X60, X70, and X80 Pipeline Steels

This study describes how microstructural constituents affected the hydrogen embrittlement resistance of high-strength pipeline steels. The American Petroleum Institute (API) X60, X70, and X80 pipeline steels demonstrated complicated microstructure comprising polygonal ferrite (PF), acicular ferrite, granular bainite (GB), bainitic ferrite (BF), and secondary phases, e.g., the martensite-austenite (MA) constituent, and the volume fraction of the microstructures was dependent on alloying elements and processing conditions. To evaluate the hydrogen embrittlement resistance, a slow strain rate test (SSRT) was performed after electrochemical hydrogen charging. The SSRT results indicated that the X80 steel with the highest volume fraction of the MA constituent demonstrated relatively high yield strength but exhibited the lowest hydrogen embrittlement resistance because the MA constituent acted as a reversible hydrogen trap site

Characteristics of the aberrant pyramidal tract in comparison with the pyramidal tract in the human brain

<p>Abstract</p> <p>Background</p> <p>The aberrant pyramidal tract (APT) refers to the collateral pathway of the pyramidal tract (PT) through the medial lemniscus in the midbrain and pons. Using diffusion tensor tractography (DTT), we investigated the characteristics of the APT in comparison with the PT in the normal human brain.</p> <p>Results</p> <p>In thirty-four (18.3%, right hemisphere: 20, left hemisphere: 14) of the 186 hemispheres, the APTs separated from the PT at the upper midbrain level, descended through the medial lemniscus from the midbrain to the pons, and then rejoined with the PT at the upper medulla. Nine (26.5%) of the 34 APTs were found to originate from the primary somatosensory cortex without a primary motor cortex origin. Values of fractional anisotropy (FA) and tract volume of the APT were lower than those of the PT (<it>P </it>< 0.05); however, no difference in mean diffusivity (MD) value was observed (<it>P ></it>0.05).</p> <p>Conclusion</p> <p>We found that the APT has different characteristics, including less directionality, fewer neural fibers, and less origin from the primary motor cortex than the PT.</p

A Distributed Inference System for Detecting Task-wise Single Trial Event-Related Potential in Stream of Satellite Images

Brain-computer interface (BCI) has garnered the significant attention for their potential in various applications, with event-related potential (ERP) performing a considerable role in BCI systems. This paper introduces a novel Distributed Inference System tailored for detecting task-wise single-trial ERPs in a stream of satellite images. Unlike traditional methodologies that employ a single model for target detection, our system utilizes multiple models, each optimized for specific tasks, ensuring enhanced performance across varying image transition times and target onset times. Our experiments, conducted on four participants, employed two paradigms: the Normal paradigm and an AI paradigm with bounding boxes. Results indicate that our proposed system outperforms the conventional methods in both paradigms, achieving the highest $F_{\beta}$ scores. Furthermore, including bounding boxes in the AI paradigm significantly improved target recognition. This study underscores the potential of our Distributed Inference System in advancing the field of ERP detection in satellite image streams

A Crystal-Less Programmable Clock Generator With RC-LC Hybrid Oscillator for GHz Applications in 14 nm FinFET CMOS

This paper presents a crystal-less programmable clock generator. The programmable clock generator takes advantages of both RC and LC oscillators. The frequency reference is generated by the RC oscillator without using expensive external crystals. The sawtooth signal generated from the RC oscillator is sampled by low phase-noise differential clocks which are divided from the LC oscillator. The timing information is then amplified by the sampler which uses hysteresis. An additional block, gain adjuster (GA), reduces lock time and dithering. After the system gets locked, it achieves 0.01 %/V and 25.5 ppm/degrees C frequency variations for 100 MHz generated clock. The 14 nm FinFET CMOS programmable clock generator draws 28 mA current from a single 1.8 V supply and occupies an active area of 0.12 mm(2)(.) It achieves 163 dBc/Hz FoM for 100 MHz test clock.N