• Air-to-Air Heat Recovery Devices for Small Buildings

      Zarling, John P. (1982-05)
      With the escalation of fuel costs, many people are turning to tighter, better insulated buildings as a means of achieving energy conservation. This is especially true in norther climates, where heating seasons are long and severe. Installing efficient well sealed vapor barriers and weather stripping and caulking around doors and windows reduces cold air infiltration but can lead to damaging moisture buildup, as well as unpleasant and even unhealthy accumulations of odors and gases. To provide the necessary ventilation air to maintain air quality in homes while holding down energy costs, air-to-air heat exchangers have been proposed for residential and other simple structures normally not served by an active or forced ventilation system. Four basic types of air-to-air heat exchangers are suited for small scale use: rotary, coil-loop, heat pipe, and plate. The operating principles of each of these units are presented and their individual advantages and disadvantages are discussed. A test program has been initiated to evaluate the performance of a few commercial units as well as several units designed and/or built at the University of Alaska. Preliminary results from several of these tests are presented along with a critique on their design.
    • BERG2 Micro-Computer Estimation of Freeze and Thaw Depths and Thaw Consolidation

      Braley, W. Alan; Connor, Billy (1989-06)
      The BERG2 microcomputer program uses a methodology similar to the Modified Berggren method (Aldrich and Paynter, 1953) to estimate the freeze and thaw depths in layered soil systems. The program also provides an estimate of the thaw consolidation in ice rich soils. BERG2 differs from the original Modified Berggren method since it uses the actual frozen and unfrozen material thermal properties instead of average alues. This approach improves the accuracy of the prediction. BERG2 provides an improved user interface over the original BERG program (Braley, 1984). It also requires less input as a result of the ability to compute many of climatic parameters from the more common data. As a result the user required input is significantly reduced. This manual provides the user information concerning the use of BERG2, its strengths and its limitations. It also provides a discussion of the equations used in development of the program for those who wish a better understanding of the analysis process.
    • Cogeneration and Diesel Electric Power Production

      Johnson, Ronald A. (1989-09)
      We have developed a data acquisition system to both monitor the efficiency of a diesel-electric generator set in producing electricity and to evaluate its performance as part of a cogeneration system for producting both heat and electricity. We have used this system to evaluate the performances of a 45 kW system consisting of a Mitsubishi engine coupled to a Stamford generator and an 80 kW Caterpillar system. We find that, even though the efficiency of a generator set in producing electricity decreases appreciably as the electric load decreases, the cogeneration efficiency is relatively insensitive to load. The latter includes both the electric power produced and the rate of heat recovery from the jacket water as benefits. We also found that the engine temperature as measured by jacket water temperature can be maintained at high levels even at low loads if the cooling mechanism is restricted. We accomplished this in a laboratory situation by decreasing the water flow through an externally-mounted heat exchanger used to provide a source of cooling for the engine. We also found that the 80 kW cogeneration system at Coldfoot provided about one-third of the space heat needed by the maintenance shop. The payback period was less than 2 years for this system with about 2200 gallons of fuel oil being saved annually because of heat recovery from the jacket water. Volume I contains the main body of the report; appendices are contained in Volume II.
    • Competitive State-of-the-Art Structural Engineering

      Baffrey, Dylan; Anderson, Elliott; Estas, Kathryn (2017-05-15)
      The University of Alaska Fairbanks College of Engineering and Mines has a legacy with the Steel Bridge Competition. Each year, since starting nearly three decades ago, the university has pushed the limits of the competition through vigorous ingenuity and teamwork. Having a small team, where funding is hard to come by and manufacturing is all done in-house, the team would seem to be at a disadvantage. However, the team has used their obstacles as challenges to overcome rather than to deter them. Through various community outreach activities, volunteering, and professional networking the Steel Bridge team gets involved with Fairbanks and raises enough funds for materials and travel to the Pacific Northwest and then onto National Conferences. Through in-house fabrication, the Steel Bridge Team learns hands on welding and design testing, and the value of transparency between design and construction. The team also focuses on building itself, developing the people around them into better, well-rounded, well-spoken and hardworking engineers of Alaska’s future.
    • Competitive State-of-the-Art Structural Engineering

      Hjortstorp, Daniel P. (2015-04-20)
      The annual Steel Bridge competition was created over two decades ago to foster excellence and ingenuity among civil engineering undergraduate and graduate students across the nation. The steel bridge competition is one of many great opportunities to get involved in extracurricular activities associated with the civil engineering field. The University of Alaska Fairbanks (UAF) has a long history of strong performance. We are nationally known for placing well in both the regional and national competition. Students design and manufacture 1/10 scale bridges with which they compete in a regional competition and if successful a national competition. The Pacific Northwest (PNW) Regional conference is usually held mid-April each year. Much preparation and work led up to this high point of the year. The steel bridge competition teaches students valuable skills that few other engineers have the chance or ability to learn, making steel bridge team members extremely valuable employees to their future employers. Together, students tackle and overcome tremendously technical work under conditions such as extreme sleep deprivation and strenuous class loads. As a team we overcame severe financial trials, technical challenges, and tight deadlines. The 2015 competition was held at the Idaho State University in Pocatello, Idaho. The UAF Steel Bridge team swept the competition by winning seven out of seven categories and will compete for the national title on May 23rd in Kansas City. In addition to designing and building a steel bridge, members of the team also fulfilled hundreds of hours of community service and public speaking. They also support and comprise the core of the UAF Associated General Contractors (AGC) and the American Society of Civil Engineers (ASCE) student organizations. Steel bridge members sacrifice time with loved and dear ones as well as sleep and time allotted for homework in order to conquer one common goal; to design and manufacture the best bridge in the Pacific Northwest!!!
    • Cordova Floating Ferry Dock

      Metzger, Andrew T. (2014-12)
      This study began the evaluation of the Cordova floating ferry dock using the ANSYS AQWA software. The AQWA software models the effects of waves, wind and current on floating structures. Floating bodies are modeled as a point-mass with inertial and hydrostatic characteristics. As part of the study, the critical wave characteristic was defined. During the modeling it was found that AQWA can only model rigid bodies and that the Cordova floats experience a wide range of wave periods and directions. Consequently, AQWA requires adaptation to fully model the ferry dock at Cordova.
    • Corrosion of Steel in Calcium-Magnesium-Acetate (CMA) Deicier

      Venkatesh, Eswarahalli S.; Kutterer, Stephanie (1985-01)
      The corrosiveness of a new road deicer, Calcium Magnesium Acetate (CMA), was determined under various conditions of temperature, pH, and concentration. The corrosion rates of steel in CMA solutions were generally found to be of the order of 2 mils per year (mpy). In comparison, for the currently used chloride salt deicers the corrosion rates can range from 25-80 mpy. CMA is generally found to be a non-corrosive medium compared to sodium and calcium chloride. Although this preliminary corrosion research indicates that CMA is less corrosive to steels than salts, further work is necessary to confirm the corrosion characteristics of CMA on other materials. Additional studies should be performed on environmental and aesthetic aspects before widespread application of CMA as a road deicier.
    • Creep Behavior of Shallow Anchors in Ice-rich Silt

      Zhang, Xiong; Chen, Liangbiao; Lin, Chuang; McHattie, Robert (2013-07)
      Grouted anchors have become a common technique in the application of earth retention systems, slope stability problems and tie-down structures in unfrozen soils due to its cost and time efficiency. However, within much of Alaska area, permafrost is a common type of soil and might contain large amount of visible ice. The highly time and temperature dependent properties of ice-rich soil make it a challenge for the application of anchors in permafrost area. This project valuates the effect of water content and temperature on the creep behavior of shallow anchors in cold room lab. Also, field test was conducted to determine effectiveness of three types of grouting materials, including Bentonite clay, Microsil Anchor Grout and special cement formula. The temperature along the anchor was monitored to evaluate the degradation of the surrounding frozen soil. Research results may be applicable in the design of shallow anchors in ice-rich permafrost at various ice content and temperature range. Also, the load distribution and the pullout test results could give a general guidance for the shallow anchor design in permafrost area.
    • Current thermal state of permafrost and potential impact on the El Niño Southern Oscillation (ENSO) in the Southern Peruvian Andes

      Yoshikawa, Kenji; Úbeda, Jose; Masías, Pablo; Pari, Walter; Vásquez, Pool; Apaza, Fredy; Callata, Betto; Luna, Gonzalo; Concha, Ronald; Iparraguirre, Joshua; et al. (2018)
      Tropical, high-mountain permafrost has a unique thermal regime due to its exposure to strong solar radiation and to the rougher surface snow morphology (due to an increased occurrence of penitentes -- that is, snow spikes and ridges ranging from centimeters to meters in height) which reduce convective sensible heat transfer from the surface. Latent heat transfer and higher albedo occurring during the wet season contributes to positive feedback that supports the presence of permafrost. This preliminary study reports on the thermal state of Peruvian permafrost. It evaluates the potential combined impact of the El Niño Southern Oscillation (ENSO), along with the eleven-year solar cycles of Coropuna (15°32′S; 72°39′W; 6,377 m a.s.l.), and the Chachani volcanic complexes (16°11′S; 71°31′W; 6,057m a.s.l.); both mountains are located in the western Central Andes (e.g., west edge of the Altiplano). Temperature monitoring boreholes were established at 5217m on Coropuna and 5331m at Chachani, and electric resistivity was surveyed to better understand permafrost spatial distribution in these locations. This seven-year record of permafrost temperature data encompasses historically extreme El Niño and La Niña events. Our results show that the current lower-altitude permafrost boundary (ca. 5100m) is critically influenced by the balance of wet and dry seasons: permafrost tends to deplete during drought years. Typical permafrost thickness was 10-20 m and contained ice-rich pore spaces. The presence of permafrost and its thermal resistance depends on ice content and on higher albedo, usually due to pyroclastic materials (especially pumice) which are ideal materials for supporting permafrost resilience.
    • Datalogger Evaluation

      Zarling, John P.; Kinney, Thomas C.; McGilvary, Randy; Briggs, Rick (1986-01)
    • A Design of an nterface Board between a MRC Thermistor Probe and a Personal Computer

      Raskovic, Dejan (2013-09-30)
      The main purpose of this project was to design and build a prototype of an interface board between an MRC temperature probe (thermistor array) and a personal laptop computer. This interface board replaces and significantly improve the capabilities of an existing MRC RD100 readout instrument. The new interface board provides the user to test a new installation as well as read instantaneous thermistor array. The report also documents the outputs of the the MRC temperature probe for future and the operational characteristics of both the MRC RD100 and the new interface board.
    • Determination of Seasonal, Frequency and Durational Aspects of Streamflow with Regard to Fish Passage Through Roadway Drainage Structures

      Ashton, William S.; Carlson, Robert F. (1984-11)
      Optimal design of culverts for fish passage for each stream crossing requires the magnitude, duration, frequency and seasonal relationship of the flow and the timing of fish movement. Although previous studies have measured fish swimming abilities and culvert water velocity profiles, there are limited studies in northern regions of the hydrologic relationship among magnitude, duration, frequency and season of discharge for the design of culverts for fish passage. We analyzed streamflow records from 33 gaging stations in southcentral, western, interior, and arctic Alaska (from watersheds with a drainage area less than 100 sq. miles each) to determine the highest consecutive mean discharge with one-, three-, seven and fifteen-day durations, and the lowest consecutive mean discharge with three-, seven-, fourteen- and thirty-day durations. Streamflow during three seasons were analyzed: spring, April 1 to June 30; summer, July 1 to August 31; and fall, Septermber 1 to November 30. The lognormal distribution, using the Blom plotting position formula, was used to estimate flows at recurrence intervals of 1.25, 2, 5, 10 and 20 years. Multiple linear regression equations were developed to predict flows from ungaged watersheds. Significant basin and climatic characteristics for high flows were drainage area, mean annual precipitation and percent of the drainage basin with forest cover. Significant characteristics at low flows were drainage area, mean minimum January temperature, mean annual precipitation and percent of drainage basin covered by forests. This report provides the culvert designer with equations to predict flows, other than the instantaneous peak flow, for use in designing culverts for fish passage. Two example problems are given to show the application of these equations.
    • Development of a Design Method for H2Ri Wicking Fabric in Pavement Structures

      Lin, Chuang; Zhang, Xiong; Han, Jie (2016-11)
      A new roadway drainage design concept is proposed to reduce the roadway water content and enhance the overall pavement performance by implementing H2Ri geotextile with lateral wicking ability. Compared with conventional drainage materials, this type of geotextile has high tensile strength and higher specific surface area, which enable to continuously transport water under unsaturated conditions. SEM (Scanning Electron Microscope) images indicated that the geotextile functions effectively for soils with particle size larger than 12 microns. A series of tests were performed to establish the relationships among different parameters, including resilient modulus test, large-scale direct shear test, salt concentration test and pressure plate test. Test results indicated that the soil-geotextile system can work effectively to reduce the water content within the pavement structure by 2%. By doing so, the corresponding resilient modulus can be increased by 3 times and the permanent deformation can be reduced to half of that value. Meanwhile, the interface frictional strength between geotextile and soil was not sensitive to water content change.
    • Diesel Fuel Additives: Use and Efficacy for Alaska's Diesel Generators

      Kemp, Chandler; Williams, Frank; Holdmann, Gwen; Witmer, Dennis (2013-05)
    • Direct Satellite Communications

      Hills, Alex (1985-06)
      Mobile radio communications in Alaska are not always effective along our highways, marine system, and remote field sites. This ineffective mobile radio communications coverage is due in part to the lack of repeaters in appropriate locations and an excess of users on certain frequencies. Lower frequencies can propogate over hilly areas whereas higher frequencies tend to travel in straight lines and are shielded by hills, ridges, and tall buildings. A new communications system called Mobile Satellite Service (MSS) may be available for use in the State in three or four years. The MSS system utilizes a satellite link between the transmitting station to the receiving station. The system is best suited for areas with few path obstructions therefore use in remote, rural areas where other forms of communication are unavailable or unreliable is very appropriate. This interim report identifies candidate applications in the state and determines coverage which will be provided in Alaska by each of the proposed satellites. The final report will give specific recommendations for feasible applications and include a technical and economical analysis of mobile satellite operations in Alaska, specifying technical requirements and defining potential operating difficulties.