Treesearch

Vacuum kiln-drying, using low temperature in a low oxygen environment, produces light-colored hard maple in a significantly shorter drying time, and with less variability, than does conventional steam kiln-drying. To avoid chemical staining and to maintain light color, drying hard maple requires the use of high air flow at low temperature and relative humidity soon after being sawn. This study compared the color and drying times of hard maple dried in both types of kilns. Paired samples of 1-in. (25.4-mm) flat-sawn boards were dried in either a conventional kiln or a vacuum kiln, and...

Cross-laminated timber (CLT) is a mass timber product that has recently garnered considerable attention for lateral-force resisting system (LFRS) applications. The main objectives of this study were to investigate the rocking behavior of a high-aspect-ratio (height/width) CLT shear wall without post-tensioning, and to validate a finite-element (FE) model based on the cyclic and dynamic response of the wall. To this point, high-aspect-ratio walls in the literature have primarily been post-tensioned. The testing component of this study included connector tests, quasistatic cyclic shear wall...

The potential of neat poly(lactic acid) (PLA) and PLA/cellulose nanocrystal (CNC) blown films in extending the shelf-life of crackers, a moisture-sensitive food product, was assessed. Product’s shelf-life, i.e., the time required by the crackers to reach its critical moisture content (CMC) of 8%, was determined experimentally from moisture content versus storage time plots at a constant temperature (25 °C) and various conditions of relative humidity (RH). Neither crackers within PLA nor PLA/CNC packages reached the CMC when stored below 50% RH at 25 °C, indicating that crackers packaged in...

The yeast Schwanniomyces polymorphus is associated with the infrabuccal pocket in the carpenter ant Camponotus vicinus (Hymenoptera: Formicidae), but its role in ant development is poorly defned. The potential effects of this yeast on brood development were examined on sets of larval groups and workers over a 12 week period. Worker–larval sets were fed variations of a completely artifcial, holidic diet and exposed or not exposed to live S. polymorphus. Worker–larval sets in half of the experiment were defaunated using a two-step heat and chemical process. Brood development and number of...

Background: On-site enzyme production using Trichoderma reesei can improve yields and lower the overall cost of lignocellulose saccharifcation by exploiting the fungal gene regulatory mechanism that enables it to continuously adapt enzyme secretion to the substrate used for cultivation. To harness this, the interrelation between substrate characteristics and fungal response must be understood. However, fungal morphology or gene expression studies often lack structural and chemical substrate characterization. Here, T. reesei QM6a was cultivated on three softwood substrates: northern...

Aggregated states of celluloses remain poorly understood, and therefore, the topic requires careful investigation. In this study, Raman, IR, and Xray diffraction (XRDs) were used to study cotton microcrystalline cellulose (MCC) and MCC that has been ball-milled to various degrees. Raman and IR spectroscopy methods indicated that when these ball-milled samples were wet with water, most underwent conformational changes at the molecular level. Although formation of cellulose II was observed in longer duration ball-milled samples, the changes primarily gave rise to increased contributions in...

Two scalable coating techniques, slot die and spray coating (SC), are used to apply cellulose nanocrystals (CNCs) to the surface of glass fibers with the goal of enhancing interfacial interactions between glass fibers and epoxy and, consequently, the strength of fiber-reinforced composites. The quality of the cellulose coatings and the interfacial shear strength, assessed via the single fiber fragmentation test, are determined as a function of the method and conditions used to coat the fibers. In addition, a comparison with glass fibers coated with identical CNC formulations using a...

Resistance against infection by the fungus Aspergillus flavus Link in commercial maize (Zea mays L.) is the topic of many studies, but few studies have investigated the effects of A. flavus infection on gene expression levels in ear kernels. A crucial component of gene expression profiling by RT-qPCR is having a reliable set of reference genes that show relatively constant expression across the treatments and phenotypes under study. Currently, however, there is no published information on reference genes suitable for measuring changes in kernel gene expression levels after infection with...

Understanding the effects of environmental disturbances on insects is crucial in predicting the impact of climate change on their distribution, abundance, and ecology. As microbial symbionts are known to play an integral role in a diversity of functions within the insect host, research examining how organisms adapt to environmental fluctuations should include their associated microbiota. In this study, subterranean termites [Reticulitermes flavipes (Kollar)] were exposed to three different temperature treatments characterized as low (15ºC), medium (27ºC), and high (35ºC). Results...

The objective of this study was to investigate the effects of tree diameter and juvenile wood on acoustic wave propagation in standing trees. Two-layer tree models with various diameters and proportions of juvenile wood were constructed to examine the effects of these two factors on propagation patterns and velocity of acoustic waves. The simulation results and analysis indicated that acoustic wave propagation in trees is dependent on both tree diameter and propagation distance. In the context of time-of-flight (TOF) acoustic measurement on standing trees with a test span of 1.2 m, when...