Dr. Perry Peralta is an Associate Professor in the Department of Forest Biomaterials and currently serves as Undergraduate Coordinator of the Sustainable Materials & Technology program.
He obtained his Ph.D. from Virginia Polytechnic Institute and State University. He teaches Wood Physical Properties, Wood Mechanics, and Statistical Process Control.
His current research projects include the evaluation of the physical and mechanical properties of loblolly pine deficient in cinnamyl alcohol dehydrogenase, the study of the viscoelastic properties of transgenic aspen, the development of novel forest biomaterials through the application of nonwoven technologies, and the analysis of heat and mass transfer in wood, wood composites, and building envelopes.
Dr. Peralta is a member of the Phi Kappa Phi, Xi Sigma Pi, and Gamma Sigma Delta honor societies, and is an active member of the Forest Products Society and the Society of Wood Science and Technology. He is the recipient of the 2003 NC State University Outstanding Teacher Award.
Area(s) of Expertise
Wood physical properties, wood mechanics, statistical process control, development of novel forest biomaterials through the application of non-woven technologies
- Fungal Pretreatment and Enzymatic Hydrolysis of Genetically-modified Populus trichocarpa , BIORESOURCES (2020)
- ANATOMICAL, PHYSICAL, AND MECHANICAL PROPERTIES OF TRANSGENIC LOBLOLLY PINE (PINUS TAEDA L.) MODIFIED FOR INCREASED DENSITY , WOOD AND FIBER SCIENCE (2019)
- Anatomy and Chemistry of Populus trichocarpa with Genetically Modified Lignin Content , BIORESOURCES (2019)
- Thermo-mechanical Behavior of Genetically Modified Populus trichocarpa , BIORESOURCES (2019)
- Altered Lignin Content and Composition in Transgenic Populus trichocarpa Results in a Decrease of Modulus of Elasticity , BIORESOURCES (2018)
- Characterization and enzymatic hydrolysis of wood from transgenic Pinus taeda engineered with syringyl lignin or reduced lignin content , Cellulose (2017)
- Estimating annual riverbank erosion rates-a dendrogeomorphic method , River Research and Applications (2014)
- Modeling of the mechanical properties of a wood-fiber/bicomponent-fiber composite , BioResources (2013)
- Distribution of wood polymers within the cell wall of transgenic aspen imaged by Raman microscopy , Holzforschung (2012)
- Fungal biodegradation of genetically modified and lignin-altered quaking aspen (Populus tremuloides Michx.) , Holzforschung (2012)
Materials are linked to human societyÃƒÂ¢Ã¢â€šÂ¬Ã¢â€žÂ¢s progress that our historical eras are named after the dominant material of the time. This demand for raw materials has grown explosively that we are now beyond the planetÃƒÂ¢Ã¢â€šÂ¬Ã¢â€žÂ¢s carrying capacity. It is crucial to revise societyÃƒÂ¢Ã¢â€šÂ¬Ã¢â€žÂ¢s techno-economic approach to development, which strongly correlates with environmental degradation, and embrace the concept of sustainability, which balances the competing demands of the environmental, social, and economic sectors. NCSU's Department of Forest Biomaterials has successfully instituted a STEM-based Sustainable Materials and Technology undergraduate program. Program faculty proposes to extend this success to K-14 students to prepare future workforce in the holistic discipline of sustainability. The grant will focus on minority women attending community colleges since historically they have been under-represented in the forest biomaterials field. The goal is to expand their opportunities for professional careers and educational equity in sustainable materials science and engineering. This will be accomplished by providing a multitiered support system at every phase of the studentÃƒÂ¢Ã¢â€šÂ¬Ã¢â€žÂ¢s postsecondary academic career --- specifically through community support, academic mentorship, experiential learning, community research projects, professional development, and university scholarship/admission guidance. The project will enhance participantsÃƒÂ¢Ã¢â€šÂ¬Ã¢â€žÂ¢ scientific and professional competencies, leadership and communication skills, professionalism, critical and problem-solving skills, and team-building ability. The project is based on accountability; project-component outcomes will be assessed using proven methodologies. The project goal and objectives are aligned with NIFAÃƒÂ¢Ã¢â€šÂ¬Ã¢â€žÂ¢s Strategic Sub-Goal 1.7 and address WAMSÃƒÂ¢Ã¢â€šÂ¬Ã¢â€žÂ¢ Education Need Areas of Student Experiential Learning, and Student Recruitment, Retention, and Educational Equity.
NC State University proposes to develop and implement a science-based business plan to foster commercial applications of fique fiber, for that we will: ÃƒÂ¢Ã¢â€šÂ¬Ã‚Â¢ Benchmark fique properties (surface chemistry, mechanical properties) against abaca fiber ÃƒÂ¢Ã¢â€šÂ¬Ã‚Â¢ Identify potential commercial applications of fique fibers, screen options based on technical and financial feasibility and demonstrate proof of concept at bench-scale ÃƒÂ¢Ã¢â€šÂ¬Ã‚Â¢ Evaluate business cases based on profitability, supply chain, risks, and go-to-market strategies. ÃƒÂ¢Ã¢â€šÂ¬Ã‚Â¢ For those alternatives selected, propose a business development plant for operational implementation.
With the rapid increase in the world?s population, demand for wood as a material and as a fuel is expected to increase exponentially in the future. Biotechnology will play a major role in meeting this future wood demand. Traditional tree breeding has been proven effective in increasing forest productivity. Genetic engineering is also being used to produce trees that efficiently sequester carbon, are more amenable to treatment for biofuel production, and have desired wood properties. The tailoring of trees with desired characteristics for optimal processing offers a tremendous potential for the forest products industry in the United States. One factor that is crucial in this integration of biotechnology and manufacturing is the availability of individuals who have the skills of both a tree biologist and a materials engineer. The proposed fellowship?s goal is to address this issue. The project objective is to develop a training program to produce graduates with strong background in forest biotechnology, biometrics, and wood engineering. Two doctoral students will be trained in the Conservation and Renewable Natural Resources discipline (Code C) of the Forest Resources Targeted Expertise Shortage Area. One student will have an engineering background but will undergo expansive training in biometrics and forest biotechnology. The other student will have a forestry or biology background but will be provided additional training in the field of wood materials science and engineering. The fellows will start a new breed of scientists with interdisciplinary perspectives to tackle issues ranging from environmental sustainability to renewable energy.
The goal of this project is to foster the use of southern pine to manufacture Cross Laminated Timber (CLT) panels for use in North American construction. Product performance data will feed into efforts to gain building code approval and eventual public acceptance of southern pine CLT. This proposal will, using southern pine, produce both laboratory size CLT panels and full size 4' x 8' CLT panels (both 3-layer and 5-layer) . Both solid CLT panels and hollow-core CLT panels will be evaluated. Bond performance of three different adhesives, fire performance tests, and measurement of hygrothermal properties on laboratory size CLT panels will be performed. The structural performance of full-size panels will be tested for out-of-plane bending and interlaminar shear capacities. Additional tests on full size pine CLT panels will include fatigue and wind-born debris impact tests
Genetic engineering provides an alternative to traditional genetic selection approach by targeting specific traits of importance to wood utilization. With genetic engineering, significant genetic gains in trees can be realized in just a matter of years instead of the centuries required with natural selection. In forestry, DNA transfer has been achieved to impart herbicide, pest, and disease resistance to several species of hardwoods and softwoods. Recently, genetically engineered trees were produced wherein the expression of lignin biosynthetic pathway genes were downregulated using antisense technology. The transgenic trees have lower lignin content, modified lignin composition, or both. In addition, the cellulose content increased and the growth of the transgenic tree was substantially enhanced while structural integrity was maintained. The results of the study point to the tremendous potential of controlling the growth and development of trees. It is suggested by the researchers who developed the transgenic trees that the lower lignin content will lead to crops with improved pulping efficiency and digestibility. It could very well result also in wood with reduced compressive strength and less dimensional stability. This project will evaluate the anatomical, physical, and mechanical properties of the transgenic trees in order to provide a fundamental understanding of the role of lignin on shrinkage anisotropy, mechanical support of the crown, and wood viscoelasticity. This study will be the first to use transgenic trees as surrogate materials for understanding the mechanism of lignification as it relates to biomechanics and biophysics.
It is known that the amorphous nature of lignin influences the visco-elastic nature of wood and is therefore the target of process engineering during wood composites manufacture. Genetic engineering pushes the manipulation of the amorphous nature of lignin upstream while the chemical component is being laid down by the tree. Studies on the visco-eleastic properties of transgenic aspen will be the first to bridge materials science and tree molecular biology. The proposed study will propagate one wild type aspen and five lines of transgenic aspen (two with different levels of lignin content, two with different syringyl:guaiacyl ratios, and one with modified lignin content and S:G ratio) and then evaluate them for their visco-elastic properties. The experiments will be performed using a nonresonant forced vibration-type dynamic mechanical thermal analyzer set in dual cantilever bending mode. Samples with dimensions of 1.75 mm x 8 mm x 35 mm will be prepared using a microtome and then clamped into the sample holder on both ends. Sinusoidal force will be applied to the sample?s midpoint at a frequency of 3 Hertz. Single scan measurements at a heating rate of 3.0Ã‚ÂºC/min will be run from ambient to 300Ã‚ÂºC to determine the storage modulus and damping factor.
Preliminary experiments to evaluate the feasibility of using micro specimens to determine mechanical properties of solid, genetically treated wood are proposed. Micro specimens have been successfully used in determination of mechanical properties of historic timber and several semi-destructive methods have been developed by the author of the proposal. Modulus of elasticity and strength in bending, tension and compression along fibers will be measured and results will be analyzed to determine the effect of genetic treatment on mechanical properties of solid wood. Such information is vital for selection of the most effective and promising treatments.
One approach to reducing raw material cost during furniture manufacture is the substitution of expensive wood species by lower-cost hardwoods. Because it is the most expensive domestic species used for furniture manufacture, interest is high for finding a substitute for cherry (Prunus serotinas). With a price approximately 1/3 that of cherry, yellow poplar (liriodendron tulipifera) is an excellent substitute species because of its uniform texture and grain pattern as well as its excellent machining, gluing and finishing characteristics. However, yellow poplar?s white to light yellow sapwood and light brown heartwood contrast with cherry?s pinkish sapwood and reddish heartwood. To make it look like cherry, yellow poplar?s color must be modified. The most common non-staining method of wood darkening is the steaming of the material at the green condition. Steaming is widely practiced to darken the sapwood, enhance the color of heartwood, minimize the color contrast of sapwood and heartwood, and facilitate uniform finishing. There is, however, no specific recommendations in the literature that relates to the steaming of yellow poplar for the purpose of improving color. With its potential of adding value to a low cost raw material, there is a need to investigate the feasibility of the application of steaming to poplar in order to enhance its color. The proposed study will be a preliminary study that will address this issue by: (a) evaluating the effect of steaming time and temperature on the color of yellow poplar sapwood and heartwood and, (b) comparing the steamed yellow poplar wood color with that of conventionally-dried yellow poplar and cherry. Color changes due to steaming will be quantified using a spectro-colorimeter.
The overall goal of this project is to summarize the available simplified analytical models of light frame wood buildings (LFWB) under wind loads and to develop a simplified analytical method that can be used to analyze reaction forces in shear walls due to the wind loads. The wind forces are proposed because: - wind loads are more detrimental to the wood framed housing then any other natural disaster loads (such as earthquakes) - wind loads can be treated as static loads and this makes the analysis less complicated The specific tasks will include: (1) quantification of available analytical models for wind-load analysis of LFWB, (2) refining of the available connection models that can capture nonlinear and nonconservative behavior of mechanical fasteners including failure, and (3) development of a first generation simplified analytical model of a single-story LFWB for calculation of reaction forces due to the wind loads that can be used by practitioners Peralta's part: Comparison of passive roof systems for wood frame housing in the Southeast. Four small-scale units (4x4x4 ft) will be built and tested. The units will have different ventillation systems and the results will be compared.