Projects From 2005

Investigators: Mr. W. Arbegast, Director, NSF Center for Friction Stir Processing and
Dr. H. Mott, Professor, Civil and Environmental Engineering (SDSM&T)

Research Topic: Characterization of Toxic Metal Release during Friction Stir Welding of
Aluminum Beryllium Alloys

Friction stir welding (FSW) is a solid-state joining technology that is energy efficient, environmentally friendly, and versatile. A rotating pin tool is inserted into the material and traversed along the joint line. Heating is localized and generated by friction between the tool and the work piece and is enhanced by the plastic strain energy release of the metal extruding around the pin tool. High strength, high toughness and defect free joints have successfully been achieved in aluminum, steel, titanium and metal matrix composite materials. The joining of previously un-weldable alloys is now possible

One such un-weldable alloy having a nominal composition of 62% Beryllium /38% Aluminum is finding increased interest in both the NASA and Air Force communities. The FSW of this material, however, has the potential to release beryllium oxide, which has been shown to cause health problems when inhaled.

Under the RET program, the RET RA's will design, fabricate, and test a positive pressure environmental chamber and containment system which allows the safe FSW of Al-Be alloys. Multi-stage HEPA filters will be employed to capture particulate material released. During the first summer, trials will be conducted with this environmental chamber and containment system on non-hazardous (aluminum-lithium) materials to evaluate the efficiency of the containment and collection system and to standardize the

methodologies for released particle count characterization and chemical analysis. NASA LaRC has offered to work closely with the RET RA to develop the collection and containment system, which ensures that all safety standards are met.

RET RA's performing research under this program will gain experience in the friction stir welding of potentially hazardous metallic materials. They will gain experience in the health hazards involved in the FSW of Al-Be alloys and in developing the collection, characterization and chemical analysis techniques of potentially hazardous airborne particulates. Opportunities for one to three RET RA's include:

Investigator: S. S. Bang, Department of Chemistry and Chemical Engineering (SDSM&T)

Research Topic: Development of genetically engineered biosealant for crack remediation

Recently, we have introduced a biological material in remediation of the surface cracks found in natural and man-made structures. This biosealant is based on the characteristics of a common soil microorganism, Bacillus pasteurii, which can induce CaCO₃ precipitation in surroundings as long as substrates for bacterial growth and mineral ions for CaCO₃ precipitation are available. In principle, microbial CaCO₃ precipitation correlates with the expression of urease enzyme produced as part of microbial metabolism. B. pasteurii is an endospore former that can sustain the adverse environments. This inorganic CaCO₃ is an environmentally innocuous substance and persists in the environment for a prolonged period.

Our current research has introduced a novel approach using molecular techniques to construct genetically engineered microorganisms (GEMs) that are able to produce organic polymers in addition to CaCO₃ precipitation (Fig 1). Biochemical characteristics of this newly developed biosealant containing microbial organic and inorganic polymers are being examined prior to their application in concrete crack remediation.

The newly developed dual biosealant is expected to offer a synergistic effect in crack remediation, combining the beneficial properties of both organic and inorganic compounds as an effective sealant.

The RET RA will conduct laboratory experiments to develop GEMs and to identify inorganic and organic polymers produced by the recombinant microorganisms. Through active participation in our ongoing research project, the RET RA will gain experience in molecular cloning techniques and biochemical assay procedures.

Investigator: Dr. D.J. Dixon, Department of Chemistry and Chemical Engineering (SDSM&T)

Research Topic:Pretreatment of Biomass Leading to Enhanced Ethanol Production

Fuel ethanol produced in the United States comes from corn. Cellulose from waste biomass sources (wood, corn stover, grass, etc.) represents a potentially inexpensive alternative source of fermentable sugars. Significant efforts in industry, academia, and government labs have focused on ag-wastes as a feedstock replacement for corn. SDSM&T has been involved in research attempting to develop a conversion process to turn waste wood material into fuel grade ethanol. Three steps are involved in the production of ethanol from biomass: 1) pretreatment to break apart the lignocellulose structure of the biomass (see Figures 1 and 2); 2) digestion of the cellulose polymer into simple sugars using biological catalysts (enzymes); and 3) fermentation of the sugar to ethanol using microorganisms. Further research is needed to develop a commercially viable pretreatment process for biomass.

A second potential feedstock of cellulosic material that has been largely unexplored is the stream coming from the Rapid City Material Recovery Facility (MRF), which includes; paper, cardboard, and chopped brush. In this project, the RET researcher will examine the literature to learn about

previous research to convert recovered materials to fuel-grade ethanol. Laboratory work will include working with various forms of pretreatment and enzyme hydrolysis to find schemes that will promote the efficient conversion of cellulose to glucose. Subsequent fermentation testing will explore ways to promote effective conversion to fuel-ethanol. The successful RET researcher will learn about bioconversion, enzyme hydrolysis, fermentation, and product analysis. One of the mutual goals will be to provide the RET researcher with learning experiences that will readily transfer back into their everyday classroom curriculum.

Research Topic: Polymeric Membrane-based Separations and Systems

Separation techniques based on polymeric membranes has continued to be a fertile research area ever since membranes were used extensively for reverse osmosis purification of salt water. Some of the most promising applications of such research include: improved dehumidification and pre-concentration of chemical species prior to analytical analysis; improved protective suits for industries concerned with employee health and safety; improved PEM fuel-cell membranes, with potential to use alcohols formed from renewable resources; improved purification systems based on membrane and pervaporation techniques; cost effective dehydration of solvents; cost effective dehydration of

fermentation products, to include thermally sensitive materials, chemicals, proteins, etc; and others. One of the more recent techniques being examined at SDSM&T is pervaporation. Pervaporation is a separation technique that uses membranes to separate chemical species based on concentration and thermal driving forces. A mixed liquid is fed to the membrane, whereupon selective permeation through the membrane of one or more species occurs. Then, due to an elevated feed temperature or a reduced pressure on the permeate side of the membrane the permeate species vaporize and are collected as a product. The RET Research Assistant will likely be involved in an undertaking related to our current Army Research Laboratory project. This work can involve the RET-RA in making or modifying polymer membranes, membrane characterization (including SEM, see Figure 3; AFM; FT-IR; and other analytical techniques), evaluating separation performance of the membranes, learning or reviewing laboratory research techniques, statistical analysis of results and other research-related experiences. Additionally, the RET-RA will be able to explore possible ways to instruct membrane separations and polymeric membrane systems in their classroom.

Investigator: E. F. Duke, Department of Geology and Geological Engineering and Analytical Characterization and Testing (ACT) Laboratories (SDSM&T)

Research Topic: Transport of Dissolved and Suspended Compounds in Western South Dakota Streams: A Laboratory Analytical Approach

The purpose of this project is to involve middle and high school teachers in research on the chemistry of surface waters in western South Dakota. The project should be of interest to teachers in the areas of general chemistry, environmental science, hydrology, analytical chemistry, geochemistry, and biogeochemistry. A background in chemistry recommended. The project is flexible in scope and could accommodate one participant or as many as three or four teachers working as a team. The teachers would work closely with Dr. Edward Duke and Mr. Russ Lingenfelter of the analytical chemistry facilities at SDSM&T.

The primary methods in this work are field sampling of stream waters followed by laboratory analysis of dissolved metals using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). ICP-MS can detect most elements on the Periodic Table at levels of 1 part per billion or lower. A second method, if the participants are interested, is X-Ray Diffraction (XRD), which would be used to identify and quantify the percentages of different solid phases in the suspended load. Additional analytical tools that can be used are Scanning Electron Microscopy with Energy Dispersive X-Ray Analysis to examine the morphology and chemical composition of the suspended particles, and Carbon/Sulfur/Nitrogen Analysis to characterize to total amounts of these key nutrients in the suspended load.

Dr. Duke's long-term goal is to link these ground-based measurements of stream water chemistry and suspended loads with satellite-based measurements. If successful, this approach could provide a means of monitoring and modeling the transport of dissolved elements and sediment through local watersheds as well as through major drainage basins such as the Missouri River Basin.

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Budget notes: The project would require a vehicle or mileage reimbursement for participants to collect stream samples (approx. $500) and approximately $1000 per participant for use of analytical labs (ICP-MS, XRD, SEM, C/S/N Analyzers).

Facilities: Agilent 4500 quadrapole ICP-MS; Rigaku Ultima Series XRD (new in 2003); JEOL 840 SEM with Oxford ISIS image analysis and X-ray analyzer; LECO CS-600 and TCH-600 analyzers for carbon, sulfur, nitrogen, hydrogen, and oxygen (new in 2003).

Dr. Duke's recent involvement in K-12 education includes the following activities carried out in collaboration with Oglala Lakota College:

1. Developed Earth Science modules for the NASA Honors Program (2003-04), a six-week, pre-college summer residential program at SDSM&T that aims to increase the participation and success of American Indians in science, math, and technology.

2. Presented "Rocks and Minerals" and "Reflectance Spectroscopy of Minerals and Remote Sensing" demonstrations for fifth through eighth grades at schools on the Pine Ridge Reservation (2003).

Investigator: Dr. Christopher H.M. Jenkins, Professor of Mechanical Engineering
Compliant Structures Laboratory (SDSM&T)

Research Topic: Biomimetics: Damage Tolerance in Spider Webs

Human engineers have taken direction from nature since the earliest of times. Formerly called biomimetics or the mimicking of biology, this is in fact a specialized branch of reverse engineering. The fundamental feature that makes nature such a wonderful paradigm for mimicking is the ability of natural designs to evolve toward optimal designs. In a very many cases, natural designs have had millions of years, and a large number of tries, to get it right. Other features, such as growth, self-repair, and intelligence are also highly attractive to human engineers. Nature must fabricate and maintain at low cost - cost in terms of energy expended. Natural artifacts that are of the highest sophistication are also structurally compliant or flexible. The ability for a plant or animal to be compliant allows it to incorporate features, such as intelligence, to the highest degree.

           This project will look specifically at spider webs. While a considerable body of literature exits concerning the chemistry of spider silk, little work has been done on the web as a structure. Why does the spider web look the way it does? What is it about the web topology that utilizes the silk material and makes the web so structurally efficient, even in the presence of significant damage? Is web spinning a paradigm for in-situ manufacturing in space?

         Structural testing of nets has already begun at the Compliant Structures Laboratory (CSL) at SDSM&T. Nets were used as proxies for real spider webs, and novel dynamic testing using CSL's scanning laser vibrometer was accomplished. RET RA's will build on this preliminary work,

progressing toward the use of real webs. RET RA's will first develop the capability for CSL to grow and maintain spider webs in the lab environment. A certain amount reflectivity from a surface under investigation with the laser vibrometer is required. RET RA's will investigate the natural reflectivity of spiders silk; if found to be insufficient, then techniques to improve the reflectivity will be pursued, such as painting on a solution of liquid containing tiny glass sphere. Methods to take digital images of webs and prepare them for computer simulation will be explored. Finally, RET RA's will develop techniques to systematically damage the webs and determine their dynamic response.

The RET RA will have the opportunity to work with other engineers and engineering students in a nationally recognized research laboratory (www.compliantlab.sdsmt.edu). In addition to the fun learning experience, the RET RA will take away many ideas and supporting material for incorporation into classroom activities.

Investigator: Dr. Katherine McCarville (SDSM&T) and Dr. Bob Chandler, Associate
Professor of Biology, Georgia College and State University

Research Topic: Avian Paleontology

The participating teacher(s) will use GIS and 3-D visualization technologies, both of which are powerful educational tools and have important workplace applications. The participants will gain understanding of and ability to work with X-ray and SEM equipment and images, learning about scientific instrumentation. We will use medical technologies, scientific instrumentation, imaging, maps and spatial analysis, geology, paleontology and paleobiology, and the scientific method. We will discuss with teachers how they might use this new knowledge and possibly some of these methods in their own classes.

Teachers will work with museum fossil specimens and cataloging systems, both locally and via on-line access. We are likely to spend some time in the field, re-locating existing avian localities and discovering new ones!

This project also involves employing a new technique for the study of bird eggshells using scanning electron microscope (SEM) images to examine the cross-sectional structure and inner and outer surfaces that has recently been pioneered. Figure 1 is an image of a portion of a fossil bird eggshell made on the SDSM&T SEM equipment. It is very possible that we will discover new taxa of birds that have not previously been known from the Big Badlands or from rocks of this age. We would be among the first researchers to apply the SEM technique to fossil eggshells. Teachers might expect to co-author a peer-reviewed publication based on our work together.

Investigator: Dr. J.J. Stone (SDSM&T)

Research Topic: The Biological Reduction of Iron Oxides for Hazardous Waste Remediation.

The contamination of soil and groundwater by heavy metals and radionuclides as a result nuclear weapons development is widespread throughout the US. Ongoing research is applying novel approaches for the containment or removal of these so-called "legacy" wastes. An innovative method for treatment of these contaminated sites is the use of dissimilatory metal-reducing bacteria (DMRB), such as anaerobic bacteria Shewanella putrefaciens, to facilitate in situ immobilization of previously mobile metal contaminants such as Cr(VI), U(VI) or As(III). This research will investigate the inhibitory effects of heavy metals on the biological reduction of Fe(III)-oxides in the presence of natural organic matter (NOM). The RET RA will perform a series of batch experiment to mimic conditions commonly found at contaminated sites, and will assess the effect that heavy metals (Pb²⁺, Cd²⁺, or Zn²⁺) and NOM may have on the bioreduction processes.

The RET RA will gain a better understanding of biogeochemical processes controlling fate and transport of contaminants within the subsurface environment. The participant will learn various techniques related to working with anaerobic microorganisms through cell culturing, performing batch iron reduction experiments, and measuring cell viability using a fluorescing microscope. The RET RA will also have hands on experience using various environmental-related analytical instrumentation such as the flame atomic adsorption spectrophotometer (AAS) and the UV-Visible spectrophotometer, Scanning Electron Microscope (SEM), and X-Ray Diffraction (XRD). Finally, the RET RA will be involved in data analysis and derive conclusions based upon experimental outcomes.

Through this research project, the RET RA will gain a better understanding of the inherent complications of "legacy waste" cleanup, and will have a better knowledge of processes affecting biological remediation.

Investigator: Dr. R. M. Winter, Department of Chemical Engineering (SDSM&T)

Research Topic: Manmade and Natural Composite Interphase: Inter-relationship of Chemistry and Mechanics

One of the most critical aspects of the performance of the composite material is the strength of the adhesion between the matrix and the reinforcement. In manmade composites coupling agents and modifiers are used as surface coatings to improve the dispersion of the reinforcement and to improve the adhesion and wettability between the reinforcement and the polymeric matrix. Despite the several billion pounds of composite materials used per year in the United States, the fundamental molecular level understanding of the manner in which the coupling agents and modifiers work to enhance the performance of macro- and nano-composites is lacking. The goal of his research is to develop the fundamental understanding (13), new techniques (14), and advanced instrumentation (15,16) to determine the structure, composition, properties and performance of materials (13,17), as well as the relationships among these elements.
The RET RA's will learn fundamental materials science and engineering of composite systems, of the importance of functionally graded properties to achieve unique composite properties, and the usefulness of looking within Nature for examples to mimic. Depending on the aspect of the project they are working on they will have the opportunity to learn about and when possible operate advanced instrumentation such as the interfacial force microscope, the atomic force microscope, scanning electron microscope, FT-IR spectrometer, laser Raman spectrometer, and contact angle goniometer.