Engineering Commons^™

Development Of Food Packaging Films Based On Cellulose Nanocrystals (Cncs), Cong Chen

Electronic Theses and Dissertations

Food packaging provides means to mitigate food spoilage caused by microbes and environmental exposure, as well as prolonging the shelf life of food products in a cost-effective manner that industry and consumers desire while minimizing environmental impact. However, conventional plastics are unsustainable, nonrenewable, as well as nondegradable, and coupled with single-use culture can cause serious environmental pollution and the loss of resources. Taking the above issues into consideration, bio-based materials with the required properties are desirable to address the end-of-life issues for packaging.

Cellulose nanocrystals (CNCs), as a major type of cellulose nanomaterials are directly extracted from renewable biomass resources …

Biobased Packaging Materials From Cellulose Nanofibrils Produced From Virgin Wood Pulp Or Recycled Cardboard Pulp, Md Ikramul Hasan

Electronic Theses and Dissertations

Self-standing cellulose nanofibril (CNF) films are regarded as one of the promising alternatives to current petroleum-based packaging materials. The mechanical and barrier properties of CNF films are not yet up to the mark for certain applications, especially at high relative humidity. Those properties of CNF films can be tuned by the drying methods of films, degree of fibrillation, cross-linking, and controlled shrinkage. A comprehensive understanding of these processes and their influence on the structure and properties of CNF films have been presented in this thesis.

First, we prepared CNF films from CNF suspensions with two different degrees of fibrillation- standard …

Quantifying Spatial Heterogeneity Of Wild Blueberries And Crop Water Stress Monitoring Using Remote Sensing Technologies, Kallol Barai

Electronic Theses and Dissertations

The wild blueberry is one of the major crops of Maine, with significant economic value and potential health benefits. Due to global climate change, drought impacts have been increasing significantly in recent years in the northeast region of the USA, causing significant economic losses in the agricultural sectors. It has been predicted to increase further in the future. Changing patterns of the elevated atmospheric temperatures, increased rainfall variabilities, and more frequent drought events have made the wild blueberry industry of Maine vulnerable, suggesting the adoption of novel approaches to mitigate the negative impacts of global climate changes. Also, wild blueberry …

Investigating 3d-Printability Of A Maine-Based Bio-Ink, Jordyn Judkins

Honors College

Biofabrication is the process of creating complex biologic products, such as artificial tissues, from raw materials such as living cells, biomaterials, and molecules. This can be done using 3D printed bio-ink, which is a combination of biomaterials and cells. However, the bio-ink must be a shear thinning fluid to allow for high-resolution and continuous printing, but also demonstrate post-printing mechanical integrity to self- support the structure, which is challenging to achieve. The research conducted here investigates how to improve the mechanical functionality of bio-ink using additives available in Maine. Chitosan, sodium alginate, and TEMPO nano fibrillated cellulose were chosen as …

Understanding The Adhesion Mechanism In Mycelium-Assisted Wood Bonding, Wenjing Sun

Electronic Theses and Dissertations

The increasing environmental awareness has led to an increased interest in developing more sustainable materials as alternatives to petroleum-derived products. Among different nature-based products, fungal-mycelium-based bio-composites have gained considerable attention in various applications. Multiple materials with different densities and structures and potential applications can be fabricated by inoculating filamentous white-rot fungi in lignocellulosic materials and other substrates. Different from lower-density as-grown foam-like mycelium composites, higher-density mycelium-lignocellulosic panels have the potential to replace commercial particleboard and fiberboard bonded by petroleum-based resins. This kind of composite can be produced by directly adding heat and pressure to the low-density foams or by assembling …

Influence Of Mechanical Properties Of Paper Coating On The Crack At The Fold Problem, Seyyed Mohammad Hashemi Najafi

Electronic Theses and Dissertations

Paper coating layers are subject to various stresses and deformations in many converting processes such as calendering, printing, slitting, and folding of the paper. In some cases, products may crack during folding to generate a defect called cracking at the fold (CAF). The parameters that influence these defects are not well understood. The overall goal of this thesis is to better understand the CAF behavior as related to material properties of the coating layer.

A method was developed to produce free-standing pigmented coating layers thick enough to be tested in bending as well as tension. The mechanical properties of these …

Spray-Dried Cellulose Nanofibril-Reinforced Polypropylene Composites For Extrusion-Based Additive Manufacturing, Lu Wang

Electronic Theses and Dissertations

Compared to conventional manufacturing process, additive manufacturing (AM) offers free-form design, lighter and more ergonomic products, short lead time and less waste. Extrusion-based AM can be used to print thermoplastics. However, extrusion-based AM has processing challenges in printing semi-crystalline thermoplastics, for instance, polypropylene (PP). Cellulose nanofibrils (CNF) are one type of cellulose nanofibers that are produced from pulp fibers. CNF has extraordinary properties which make it an ideal candidate to reinforce polymers. Spray-dried CNF (SDCNF) is able to be incorporated into thermoplastic matrices without modifying conventional processing procedures.

The mechanical properties of 3D printed plastic parts have been considered significantly …

So2-Alcohol-Water Fractionation Of Sugarcane Straw, Asif Sharazi

Electronic Theses and Dissertations

Climate change resulting from fossil fuels combustion is motivating researchers to explore feasible routes to convert renewable biomass into biofuels and biochemicals for a sustainable society. Typically, biofuel is produced from corn or sugarcane but both feedstocks compete with human food supply. Thus, lignocellulosics as renewable feedstock represent a more ethical and ecofriendly approach. Sugarcane straw (SCS) is a cheap and abundantly available feedstock which potentially can be used for biofuels/biochemicals production. It can also help to mitigate environmental and health problems resulting from conventional practice of SCS burning in the fields.

There are different biomass conversion technologies for production …

Place-Based Approaches To Alternative Energy: The Potential For Forest And Grass Biomass For Aroostook County, Jason Johnston, Soraya Cardenas

Maine Policy Review

Teams at the University of Maine Presque Isle and the University of Maine at Forth Kent are engaged in evaluating the potential for forest and grass biomass energy in Aroostook County, funded through Maine’s Sustainability Solutions Initiative. The article discusses how this potential is being evaluated and the possible ways in which expanding grass and wood biomass might benefit farmers and residents of The County. It suggests that using some of Maine’s farmland for fuel might be sustainable with appropriate management and with consideration for potential environmental and socioeconomic drawbacks

Biomass And Biofuels In Maine: Estimating Supplies For Expanding The Forest Products Industry, Jonathan Rubin, Kate Dickerson, Jacob Kavkewitz

Energy & the Environment

This paper estimates the renewable energy potential of Maine’s forest resources, and how much energy these resources could potentially provide the state. Using the most recent state-specific data available, and a methodology similar to the Billion Tons Report, we find that ethanol production from Maine’s forest residues could potentially provide 18% of Maine’s transportation (gasoline) fuels with a fermentation wood to ethanol process. Making Fischer-Tropsch diesel (F-T diesel) using forest residues can replace 39% of Maine’s petro-diesel consumption. Actual levels of biofuels that can be produced will depend on conversion factors and forestry residue removals that are subject to uncertainty.

Measuring The Adhesive Bond Quality Of Vinyl Ester-Glass Composites On Novolak Hmr Treated Wood, Leopold Eisenheld

Electronic Theses and Dissertations

The objectives of this research were to 1) reduce the drying time of novolak-based HMR coupling agent, 2) reinforce wood samples with E-glasslvinyl ester resin composite using the SCRIMPThq process, 3) evaluate the durability and strength properties of the FRP-wood composites, and 4) evaluate the bonding strength of wood-to-wood bonding using vinyl ester resin. To reduce the drying time of HMR-treated wood laminates, a randomized complete three factorial experiment was used to evaluate five HMR drying times, two HMR spread rates, and two HMR solids contents. The experiment evaluated the sensitivity of the HMR treatment process to accelerated drying. The …

Effects Of Strand Geometry On Selected Properties Of Long-Stand Structural Composite Lumber Made From Northeastern Hardwoods, Russell Edgar

Electronic Theses and Dissertations

Structural composite lumber (SCL) products often possess significantly higher design values than the top grades of solid lumber, making it a popular choice for both residential and commercial applications. The enhanced mechanical properties of SCL are mainly due to defect randomization and densification of the wood fiber, both largely functions of the size, shape and composition (species) of the wood element. Traditionally, SCL manufacturers have used thin, rectangular elements produced from either moderate density softwoods or low density hardwoods. Higher density hardwood species have been avoided, as they require higher pressures to adequately densify and consolidate the wood furnish. These …

Localization Of Expansin Expression During Adventitious And Lateral Rooting In Response To Auxin In Loblolly Pine, Fuyu Xu

Electronic Theses and Dissertations

Loblolly Pine is the most important and widely cultivated timber species in the southern United States. Due to its fast growth, it is extensively planted for lumber and pulpwood. Vegetative propagation will enhance gains from genetic improvement of tree species. Rooted-cutting is at present the most reliable non-somatic embryogenesis method for cloning specific genotypes. However, an abrupt decline of adventitious rooting capacity has hindered the application of vegetative propagation in loblolly pine. Unraveling the rooting mechanism may facilitate a way to overcome this barrier. Regulation of lateral and adventitious root formation by auxin has been demonstrated through the application of …

Tb179: Oxygen Supplementation For Aquaculture Biofilters, John Riley, Daniel Hagopian

Technical Bulletins

There is conflicting evidence concerning the negative effects of high concentrations of dissolved oxygen on nitrifying bacteria. This project was developed to determine what happens to an established slime layer in a fixed-film, flow-through bio-filter, exposed to oxygen supersaturation. Specific objectives were to determine qualitatively and quantitatively whether the treatment is actually beneficial after acclimation, and whether rapid fluctuations in DO are detrimental to an acclimated culture.

Artificial Recharge Of Groundwater As A Water Management Option For Eastern Maine, Robert J. Saunders

Electronic Theses and Dissertations

The declining population of Atlantic salmon in eastern Maine has brought the wild blueberry industry's irrigation practice of pumping water directly from ponds and streams under scrutiny. Restrictions on pumping from streams has prompted the industry to seek new water resources. One resource with potential to assist the industry to meet its irrigation needs is groundwater. However, preliminary research has shown that groundwater is not capable of completely satisfying irrigation needs. To evaluate the potential that artificially recharging the groundwater during spring run-off to retain the water for later use as irrigation, the groundwater software Visual MODFLOW was applied. Inputs …

Tb177: Evaluation Of An Experimental Filter Medium For Water Re-Use Systems, John Riley, David Cole, Robert Bayer

Technical Bulletins

This report describes the development and testing of a new material for use as a filter medium in recirculating aquaculture systems and other water quality control situations. The material consists of a combination of activated carbon and a hydrophilic urethane foam in a homogeneous matrix. Its physical properties relevant to filtration were determined. It was then tested for its ability to remove various dissolved organic compounds and inorganic nitrogenous compounds in the form of a synthetic waste-water containing ammonia and nitrite. Finally it was subjected to long-term use in the biofilter of a fish culture system. It proved to be …

Evaluating The Durability Of Wood/Frp Bonds Through Chemical Kinetics Using A Range Of Mechanical Test Methods, Jonathan Philip Alexander

Electronic Theses and Dissertations

Hybrid composites of wood and fiber reinforced polymers (FRP) exhibit a flexibility of design properties through choices in fiber type, amount, orientation and resin type. With this flexibility comes the need to measure the durability of the composite material system, especially the bond between these two materials due to their markedly different responses to moisture. This study is two-fold; the first section examines methods for the mechanical testing and durability of wood/FRP laminations. Six mechanical tests were evaluated and a modified block shear method was identified as the most suitable due to its ability to provide representative results independent of …

Tb174: Maine Wild Blueberries Field Winnowing Systems, Darrell W. Donahue, Alfred A. Bushway, Keith E. Moore, Ben J. Lagasse

Technical Bulletins

The objective of this study was to determine if there were differences in berry quality between the two winnowing systems currently used in the Maine wild blueberry industry. The following experiment was performed three times during the 1997 field season.

B521: Containers For Shipping Apples, Homer C. Woodward

Bulletins

Studies since 1946 affirm that the major causes of apple bruising in Maine are the methods used in packing the containers, layer materials, and handling. During the past two years, the emphasis of the studies has been testing of different containers and packing materials to determine which give the apples the best protection. Those who pack apples have become increasingly conscious of the higher costs involved. Therefore, the cost of the various containers and packaging materials also was studied. Thus, the overall objective of the study was to determine what type(s) of container or containers and materials give the best …