Potential Research Projects

Potential Research Projects:

Following are some of the projects participants will be working on with the corresponding faculty:

Dr. Doug Gardner, Advanced Structures and Composite Center:

Wood Flour Production from Secondary Processing Mill Residues in Maine

The state of Maine produces a significant amount of secondary processing wood mill residues but currently the commercial production of wood flour does not occur.  Most secondary processing wood mill residues are combusted for energy, used to make solid fuel pellets for residential wood stoves, wood bedding for horses, etc. Maine is home to a wood plastic composite decking manufacturer (Barrette Outdoor Living, Inc.) who currently has to source their wood flour feedstock from out of state (St. Hyacinth Quebec), and would be open to sourcing the wood flour feedstock locally if the costs were optimal (Personal communication, Mike Hurkes). Equally important is another aspect focusing on the logistics and supply chain of the product, which often is a major constraint deciding the final cost of the end-product. Transportation of forest products generally comprises anywhere from 20¬50% of the entire operational costs (Halbrook and Han 2005; Bisson et al. 2014; Kizha et al. 2015). A nationwide study reported the average hauling distance for primary forest products was highest in the northern states of the US, which increased the price of finished products substantially compared to other regions (Libbey 2000). In Maine, the forest products industries being scattered throughout the state leads to long distance travel to reach the final point of utilization (Lilieholm et al. 2010). Therefore, improvements in transportation may yield significant overall cost reductions. Research Steps

  1. Perform state of the art literature review on wood flour production.
  2. Obtain secondary mill wastes (kiln dried) from selected mills below.

White Pine (Robbins or Hancock Lumber; Pleasant River in Hancock)

Northern White Cedar (Katahdin Forest Products)

Spruce-Pine-Fir (Irving Ashland;Pleasant River; Stratten Lumber)

Hardwoods (Lumbra Milo; Kennebec Lumber Solon)

  1. Produce wood flour fractions, e.g. 20, 40, 60, 80 mesh, etc. using the hammermill and screening systems available in Perkins Hall and ASCC. A Power Logger (Fluke Corporation, Everett, WA) will be used to measure the electrical energy consumption of the milling process of the hammer mill. The total energy consumption, a sum of idle energy and net energy, will be derived from the recorded active power and milling time. The idle energy can be calculated through the baseline power of the hammer mill under a run operating without a charge and milling time. The net energy is calculated by subtracting the idle energy from the total energy.
  2. Characterize the wood flour(s) produced. Particle size distribution, morphology, moisture content, bulk density. After milling, the resulting particles will be sieved with a Ro-Tap Shaker (The W. S. Tyler Company, Cleveland, Ohio) for 20 minutes to analyze the size distribution, geometric mean diameter (Xgw), and standard deviation (Sgw) following ASAE Standard S319.4 (2008).

Dr. Mehdi Tajvidi, School of Forest Resources:

Investigation of shape memory and insulation properties of low-density structures made of lignocellulosic materials

 The scope of work for the prospective REU 2020 student at the Lab of Renewable Nanomaterials (LRN) will be focused on two main topics: 1) the investigation of shape memory properties of a range of crosslinked lignocellulosic materials and 2) the evaluation of thermal insulation of low-density lignocellulosic panels that are based on cellulose nanofibrils as a binder.

For topic #1: Previous investigations at LRN demonstrated the ability of crosslinked cellulose nanofibrils (CNF) to recover its initial shape within a few seconds upon wetting. This raises questions about the shape recovery behavior of other lignocellulosic materials. This study topic is expected to provide an important opportunity to advance the understanding of shape memory behavior of low-density wood-based products. The topic will also explore the usefulness of such products for specific applications.

For topic #2: Our preliminary results at LRN showed that favorable thermal insulation properties could be achieved from our low-density insulation panels. The main aim of this study topic is to assess the thermal conductivity associated with different panels formulations. Further characterization could also be conducted if time allows.

Dr. Jessica Leahy, School of Forest Resources:

The Family Forest Program of the Center for Research on Sustainable Forests has one REU position available for summer 2016. The selected student will assist three graduate students. The primary research project will involve interviewing family forest landowners and collecting field data about their forest conditions in the western mountains region of Maine. This will study will better understand social-ecological linkages between family forest certification in the American Tree Farm System and management for bird habitat. The study will compare outcomes from the Vermont Audubon’s “Bird Habitat Assessment Tool” between American Tree Farm System certified and non-certified family forests, with social perceptions of the landowners related to current forest management practices. The study site is a few hours from campus, so the project will involve overnight camping away from campus for a part of the field season. The second research project seeks to understand the relationship between social capital and beginning family forest owner engagement in forest stewardship. This project will investigate how peer learning programs — specifically the online MyLandPlan.org program — facilitates social capital development of beginning family forest owners, and how social capital affects their engagement in active forest management. They will then compare social capital levels between beginning family forest owners who participate and who do not participate in peer learning events held in Penobscot and Hancock County. The third project will involve applied social science related to state park managers’ early detection and management efforts related to forest pests such as emerald ash borer and Asian longhorned beetle.

Dr. Doug Bousfield, Chemical and Bioengineering Department:

Replacement of single use plastics with cellulose nanofibril/mineral composites.

The high interest from the public to replace single use plastics with a better option is increasing.  While many bio-polymers claim to be compostable, many actually do not break down in the environment or in ocean condition and they require a food source to produce.  Celllulose nanofibrils (CNF)  are able to bind minerals to result in a plastic like material.  This material breaks down upon long exposure to water.   However, methods to produce shapes of interest are not clear and methods to tune the rate of softening upon contact with water are yet to be developed.

Dr. William Gramlich, Department of Chemistry

Emulsion polymerization off cellulose nanofibrils for incorporation into thermoplastics

Cellulose nanofibrils (CNF) have high strength and are a potential sustainable nanomaterial that can improve the properties of thermoplastics. A key challenge to implementing CNF in thermoplastics is the challenge of removing the large quantity of water that exists in their native form. Current methods degrade the nanostructure or require significant organic solvent for production, limiting the commercial viability of the process. A summer REU intern will work to surface functionalize CNF in water through emulsion polymerization of hydrophobic polymers to improve its drying, retention of nanoscale structure, and compatibilization once compounded into thermoplastics. Two major tasks will be the focus of the summer work. The first task of this work will be to determine conditions that effectively graft polymers to the surface of CNF in water. The second task of the work will be to understand how polymer functionalization affects dewatering and CNF particle size. The student will learn about polymerization and cellulose nanomaterials as well as several experimental techniques such as infrared spectroscopy and electron microscopy.

Dr. Ling Li, School of Forest Resources

Effect of additives on the reduction of particulate matter (PM) emissions of burning solid biomass fuels for residential heating

The use of solid biomass fuels for residential heating is always taking up large popularity in the U.S., especially in rural communities. The quality of biomass solid fuels (i.e., ash content) has a significant impact on the indoor and outdoor air quality (e.g., wood smoke and PM2.5), which are vital for both human health and environmental health. Modifying solid biomass fuels by blending additives, referred to as minerals or chemicals, into biomass feedstock might be a cost-effective approach in comparison to the installation of second measures on the wood heaters. The mechanism is that some additives (e.g., kaolinite, anorthite, calcium silicate, titanium dioxide, and aluminum hydroxide) could change the ash chemistry, reduce the concentration of PM forming components and increase the ash melting temperature during the biomass combustion. Therefore, this REU project is aimed to examine the effect of potential additives on the reduction of PM emissions of burning low-quality forestry residues generated from thinning and logging. The student will identify one or two types of additives suitable for hardwood species, e.g., oak/maple/birch, and characterize the ash samples collected after combustion via elemental analysis, thermogravimetric analyzer (TGA), X-Ray Diffraction (XRD), etc.

Dr. Daniela Rios, Division of Environmental Protection, Concepcion, Chile:

Evaluation of the Enzymatic Activity in Soil Treated with a Wood-ash Amendment: Wood ashes as a soil amendment or liming agent have been used for decades, mostly in forest plantations. These provide essential nutrients and neutralize acid soils, moreover, it has been suggested that ashes have a positive impact on physical, chemical and microbiological soil properties. However, the mechanisms through which wood ashes improve the soil properties are poorly understood. In this regard, microbes provide enzymes that participate in nutrients cycles, making them available for plants, and their catalytic capacity may change in the presence of wood ashes. For example, Gómez-Rey et al. (2012) found a significant increase in the protease activity when treating soils with wood ash; whereas Zimmermann and Frey (2002) reported no changes in the enzymatic activity of protease after wood ash addition. Thus, our interest is focused on the effect of wood-ashes on soil enzymes because these play an important role in plant nutrition.

This project aims to determine differences in the microbiological-enzymatic activity of soil after a treatment of a wood ash based amendment. The objective will be achieved through:
(1) standardize two analytical methods (preselected by us) to measure enzymatic activity. The standardization will follow German et al. (2011) suggestions on optimization of enzyme methods. (2) Analyze and statically compare the enzymatic activities from the different treatments.
(3) Revise the literature on the topic and discuss the results.