This research examined the potential for using peanut husk as a fiber alternative to wood in the production of melamine-formaldehyde (MF) particleboard. MF resin was used to produce panels with one, three, six, nine or 12 percent resin contents. Modulus of Rupture (MOR), Modulus of Elasticity (MOE), Internal Bond (IB)...
Chainsaw users value cutting performance and safety. Knowledge of the forces exerted during sawing are necessary to understand and improve the cutting performance of saw chain. Additionally, cutting forces can be used to form metrics for evaluating performance tradeoffs when using a safety (i.e. low-kickback) saw chain versus a standard...
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John P. Parmigiani
Chainsaw users value cutting performance and safety. Knowledge of
Restoration programs effectively prevent or mitigate wildfires and pest outbreaks in the forest lands. The most common approach is to selectively harvest smaller and dead trees in order to preserve larger and superior trees. Ponderosa pine, Pinus ponderosa, (PP) lumber is one of the common species harvested from restoration programs...
Timber-concrete composite (TCC) solutions originated in the early twentieth century. There has been a renewed interest in TCC solutions in modern mass timber buildings, especially for floor systems. However due to lack of data, design standards, and code acceptance, TCC solutions require that new mass timber solutions be tested, and...
Cross-Laminated Timber (CLT) is a prefabricated building material that is relatively new to the United States and North America. It consists of no less than three layers of graded, dimensional lumber glued in alternating longitudinal and transverse layers to create a panel that can be used for various building applications...
Chainsaws, an indispensable tool for modern forestry operations, rely on bar lubricant to prevent rapid wear of the chain and bar. Choice of bar lubricant must balance performance, cost, and biological impact. Many bar lubricants are available, but little published work exists that conclusively ranks the performance of these choices....
This study computationally and experimentally examines the mechanisms of crack penetration, deflection and the transition between penetration and deflection. The finite element analysis based computational modeling work used strength-and-energy based cohesive-zone approach to study the effect of dimensionless parameters (e.g., interfacial incident angle, fracture-length scale, and normalized toughness) on penetration/deflection...
Most of existing commercial unsaturated polyester (UPE) resins are typically composed of a UPE and a high amount of highly volatile, flammable, and toxic styrene. The emission of hazardous styrene in the handling of the UPE resins and the preparation and use of fiber-reinforced UPE composites poses severe hazards to...
Existing pressure sensitive adhesives (PSAs) are mostly based on petrochemicals. In this study, a novel PSA based on a renewable material, methyl oleate, was prepared and characterized. Methyl oleate was first epoxidized to form epoxidized methyl oleate that was subsequently hydrolyzed and acidified to form epoxidized oleic acid (EOA) which...
Cellulose nanocrystals (CNCs) have received considerable attention over the last ten years because CNCs can be produced from renewable materials such as straw, wood, cotton, and sea animals (tunicates). CNCs are slender rods with high aspect ratios (10-100) and the final dimensions of the CNCs depend on the starting material....
This thesis presents two new approaches for the broadband, time-domain modeling of lossy transmission lines. Each approach is based on an alternative derivation of delay extraction in order to separate the line's linear phase from its
attenuation and dispersion. Augmentation networks represent the derived attenuation networks as rational function approximations....
The Advent of multi-cores allows programs to be executed much faster than before. Cryptoalgorithms use long-bit words thus parallelizing these operations on multi-cores will achieve significant performance improvement. However, not all long-bit word operations in cryptosystems are suitable for parallel execution on multi-cores. In particular, long-bit words used in Elliptic...
Dental resin composites are widely used in modern dentistry due to their aesthetic appearance. However, resin based restorations have inferior mechanical properties (fracture is the second reason for restorations replacement) in comparison to alloy based composites and their antimicrobial properties still remain poor, leading to secondary tooth decay development on...
Understanding the mechanical behavior of composite materials requires extensive knowledge of fracture behavior as a crack approaches an interface between the bulk material and the reinforcement structure. Overall material toughness can be greatly influenced by the propensity of an impinging crack to propagate directly through the substrate or deflect along...
The fundamental intent of the study was to develop an innovative wood-strand composite for use in structural applications. Plantation grown, low density, hybrid poplar was used in the study which was found to be appropriate for the underlying Viscoelastic Thermal Compression (VTC) process. Wood modified by this process has high...
Spraying of liquid adhesive onto wood surfaces has shown to be a highly effective and efficient method of application across many different wood-based composite industries. However, the dynamics of spraying are extremely variable and distribution can be affected by liquid properties (rheology, molecular weight distribution, and temperature), application parameters (disk...
Wood composites are an important renewable structural material which can be a net carbon sink when used in combination with sustainable forest management practices and high rates of log utilization. Adhesive bondlines are an essential part of composites, and for wood composites, they determine the moisture durability and mechanical performance...
Cross-laminated timber (CLT) is a massive engineered wood product made of orthogonally bonded layers of solid-sawn lumber, and is intended for roof, floor, or wall applications. Although it was developed in Europe in the early 90s, CLT is relatively new to North America.
CLT products must be certified for structural...
The mechanical performance of composite materials is determined by the mechanical properties of their individual components and the effective load transfer between these components. Binders are commonly used to bond composite components together and to provide effective load transfer between them. In wood-based composites the binder-component load transfer occurs at...
There is no doubt that adhesive penetration plays an important role in wood bondline joint performance and durability; yet, to date there is no direct experimental evidence linking penetration depth with bond performance. This is, in part, because adhesive penetration is commonly assessed with various 2D microscopy techniques that are...
Natural fibers are gaining popularity as reinforcement materials for thermoset resins over the last two decades. Natural fibers are inexpensive, abundant, renewable and environmentally friendly. Kenaf fibers are one of the natural fibers that can potentially be used for reinforcing unsaturated polyester (UPE). As a polymer matrix, UPE enjoys a...
High speed serial links are critical components for addressing the growing demand for I/O bandwidth in next-generation computing applications, such as many-core systems, backplane and optical data communications. Due to continued process scaling and circuit innovations, today's CMOS serial link transceivers can achieve tens of Gb/s per pin. However, most...
Formaldehyde-based adhesives such as urea-formaldehyde (UF), phenol-formaldehyde (PF) are widely applied in wood-based composite industry. However, these adhesives are all petrochemical-based and could not sustain in a long term due to a limited reserve of oil and natural gas. Moreover, these adhesives emit carcinogenic formaldehyde in the production or use...
The fabrication of nano-scale devices is a challenging, but potentially important, technology that has drawn a great deal of interest among researchers. Such nanoscale constructions utilizing a bottom-up approach for device building have many foreseeable applications in areas as diverse as miniaturized electronics, sensors, and biomedical devices.
One of the...
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John Simonsen
The fabrication of nano-scale devices is a challenging, but potentially
Two-phase gas-liquid flows in microscale fractal-like branching channel flow networks were experimentally studied to assess the validity of existing void fraction correlations and flow regimes based on superficial gas and liquid velocities. Void fractions were assessed using two different methods. First, void fraction data were acquired using a High-Speed-High-Resolution (HSHR)...
Wireless Networks have been widely adopted into a major part of today's network infrastructure. They have become a popular technology to not only expand the coverage of wired networks but also to interconnect a large wireless network, i.e., wireless mesh networks. As they allow more flexible communication than traditional wired-networks...
The emerging field of nanotechnology strictly requires the micro-scaling of the available separation technology and the design of novel devices for separations of molecules of interest. The separation of proteins and nanoparticles is challenging due to their relatively large size, non-specific adherence to surfaces and instability in many solvents.
This...
The increase of diesel fuels and natural gas has increased the energy cost of the mint
oil extraction industry in the Willamette Valley. In this study the energy evaluation of
a distillation facility in Oregon is considered. Solvent free microwave extraction of
peppermint oil is introduced as a new technique...
Polymeric composites reinforced with bio-materials have advantages over composites with synthetic reinforcements. Bio-based composites use low-cost and renewable reinforcements, have nonabrasive properties for machining, have improved damping characteristics, and have potential for energy recycling. However, the limited use of bio-based composites is because their mechanical properties are typically much lower...
Because of its attractive material properties like high hardness, high toughness, and excellent high temperature strength, materials like silicon nitride are becoming more common for use in high performance applications. However, there have been limited studies of the fatigue behavior of small cracks in silicon nitride and other materials toughened...
Rapid discoloration and checking of wooden surfaces when exposed outdoors has caused wood to fall out of favor as an outdoor building material, especially in applications where appearance is important. The surface appearance of wood products exposed outdoors can be improved through the application of film forming coatings or by...
The goal of this study was to develop an understanding of the nature of surge wave loading on
wood framed residential structures for a variety of building configurations and test conditions.
The objectives of the study were: (1) to measure forces on a 1/6th scale wood framed
residential structure, (2)...
The overall goal of this study was to gain an insight into the load sharing aspect between oriented strand board (OSB) and gypsum wall board (GWB) in shear wall assembly during racking load. More specifically the objectives of the study were to: (1) evaluate qualitatively the load sharing between OSB...
Toughened ceramics, or bridging ceramics, are being developed in an attempt
to widen the application base of traditional ceramics, which are brittle and have low
resistance to crack extension. The crack growth resistance of these extrinsically
toughened ceramics has been shown to increase with crack length, and unlike
traditional ceramics,...