988 resultados para Minnesota


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This survey began in response to widespread interest of declines in amphibians. More recently, a comprehensive statewide planning group discovered 44% of Iowa’s herpetofauna (amphibians and reptiles) to be of special concern. In response to these concerns, the Iowa Department of Natural Resources Wildlife Diversity Program (WDP) initiated an auditory survey for calling anurans to determine geographic distributions within the state. This survey has established itself as an extensive, long term monitoring program. This 2005 report is the second edition since the first report of this survey was shared in 1998 by then program biologist Lisa Hemesath. The goals of the survey are to: (1) determine the distributions of Iowa’s anuran species, (2) determine population trends for each species, and (3) promote education about aquatic life by using volunteers to conduct the survey. In addition to Iowa, volunteer-based auditory surveys for frogs and toads are currently being used in the Midwest by Wisconsin, Minnesota, Missouri, and Illinois.

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This report documents work undertaken in the demonstration of a low-cost Automatic Weight and Classification System (AWACS). An AWACS procurement specification and details of the results of the project are also included. The intent of the project is to support and encourage transferring research knowledge to state and local agencies and manufacturers through field demonstrations. Presently available, Weigh-in-Motion and Classification Systems are typically too expensive to permit the wide deployment necessary to obtain representative vehicle data. Piezo electric technology has been used in the United Kingdom and Europe and is believed to be the basic element in a low-cost AWACS. Low-cost systems have been installed at two sites, one in Portland Cement Concrete (PCC) pavement in Iowa and the other in Asphaltic Cement Concrete (ACC) pavement in Minnesota to provide experience with both types of pavement. The systems provide axle weights, gross vehicle weight, axle spacing, vehicle classification, vehicle speed, vehicle count, and time of arrival. In addition, system self-calibration and a method to predict contact tire pressure is included in the system design. The study has shown that in the PCC pavement, the AWACS is capable of meeting the needs of state and federal highway agencies, producing accuracies comparable to many current commercial WIM devices. This is being achieved at a procurement cost of substantially less than currently available equipment. In the ACC pavement the accuracies were less than those observed in the PCC pavement which is concluded to result from a low pavement rigidity at this site. Further work is needed to assess the AWACS performance at a range of sites in ACC pavements.

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The Electro-Reflective Measuring Apparatus (ERMA) was developed by the Minnesota Department of Highways in 1974 to measure the retro-reflective characteristics of pavement marking materials. Minnesota researchers recommended that due to the increased cost of pavement marking materials and reduced availability of these materials, ERMA can and should be used as a maintenance management tool to determine when painting is necessary rather than according to a fixed time schedule. The Iowa DOT Office of Materials built an ERMA device patterned after Minnesota's design in 1976. Subsequent efforts to calibrate and correlate this ERMA device to District Paint Foremen ratings proved unsuccessful, and ERMA modification or abandonment was recommended in 1979. Lyman Moothart, Materials Lab. Tech. 4, modified the ERMA device in 1980 and correlation attempts to District Paint Foremen ratings conducted in November 1980 have been moderately successful. A Paint/No Paint ERMA value has been established which will identify about 90% of the painting needs but will also include about 40% of the marking lines not needing repainting. The Office of Maintenance should establish a trial ERMA program to study the accuracy and potential cost savings of using ERMA to identify pavement marking needs.

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Anti-strip agents can effect the temperature susceptibility of asphalt cement. This concern was expressed at the 33rd Annual Bituminous Conference in St. Paul, Minnesota by Mr. David Gendell, Director of Highway Operations. This study compares viscosity-temperature relationships of asphalt cement with and without anti-strip agent addition.

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As a result of the collapse of a 140 foot high-mast lighting tower in Sioux City, Iowa in November of 2003, a thorough investigation into the behavior and design of these tall, yet relatively flexible structures was undertaken. Extensive work regarding the root cause of this failure was carried out by Robert Dexter of The University of Minnesota. Furthermore, a statewide inspection of all the high-mast towers in Iowa revealed fatigue cracks and loose anchor bolts on other existing structures. The current study was proposed to examine the static and dynamic behavior of a variety of towers in the State of Iowa utilizing field testing, specifically long-term monitoring and load testing. This report presents the results and conclusions from this project. The field work for this project was divided into two phases. Phase 1 of the project was conducted in October 2004 and focused on the dynamic properties of ten different towers in Clear Lake, Ames, and Des Moines, Iowa. Of those ten, two were also instrumented to obtain stress distributions at various details and were included in a 12 month long-term monitoring study. Phase 2 of this investigation was conducted in May of 2005, in Sioux City, Iowa, and focused on determining the static and dynamic behavior of a tower similar to the one that collapsed in November 2003. Identical tests were performed on a similar tower which was retrofitted with a more substantial replacement bottom section in order to assess the effect of the retrofit. A third tower with different details was dynamically load tested to determine its dynamic characteristics, similar to the Phase 1 testing. Based on the dynamic load tests, the modal frequencies of the towers fall within the same range. Also, the damping ratios are significantly lower in the higher modes than the values suggested in the AASHTO and CAN/CSA specifications. The comparatively higher damping ratios in the first mode may be due to aerodynamic damping. These low damping ratios in combination with poor fatigue details contribute to the accumulation of a large number of damage-causing cycles. As predicted, the stresses in the original Sioux City tower are much greater than the stresses in the retrofitted towers at Sioux City. Additionally, it was found that poor installation practices which often lead to loose anchor bolts and out-of-level leveling nuts can cause high localized stresses in the towers, which can accelerate fatigue damage.

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The effects of farm equipment on the structural behavior of flexible and rigid pavements were investigated in this study. The project quantified the difference in pavement behavior caused by heavy farm equipment as compared to a typical 5-axle, 80 kip semi-truck. This research was conducted on full scale pavement test sections designed and constructed at the Minnesota Road Research facility (MnROAD). The testing was conducted in the spring and fall seasons to capture responses when the pavement is at its weakest state and when agricultural vehicles operate at a higher frequency, respectively. The flexible pavement sections were heavily instrumented with strain gauges and earth pressure cells to measure essential pavement responses under heavy agricultural vehicles, whereas the rigid pavement sections were instrumented with strain gauges and linear variable differential transducers (LVDTs). The full scale testing data collected in this study were used to validate and calibrate analytical models used to predict relative damage to pavements. The developed procedure uses various inputs (including axle weight, tire footprint, pavement structure, material characteristics, and climatic information) to determine the critical pavement responses (strains and deflections). An analysis was performed to determine the damage caused by various types of vehicles to the roadway when there is a need to move large amounts agricultural product.

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At present, there is little fundamental guidance available to assist contractors in choosing when to schedule saw cuts on joints. To conduct pavement finishing and sawing activities effectively, however, contractors need to know when a concrete mixture is going to reach initial set, or when the sawing window will open. Previous research investigated the use of the ultrasonic pulse velocity (UPV) method to predict the saw-cutting window for early entry sawing. The results indicated that the method has the potential to provide effective guidance to contractors as to when to conduct early entry sawing. The aim of this project was to conduct similar work to observe the correlation between initial setting and conventional sawing time. Sixteen construction sites were visited in Minnesota and Missouri over a two-year period. At each site, initial set was determined using a p-wave propagation technique with a commercial device. Calorimetric data were collected using a commercial semi-adiabatic device at a majority of the sites. Concrete samples were collected in front of the paver and tested using both methods with equipment that was set up next to the pavement during paving. The data collected revealed that the UPV method looks promising for early entry and conventional sawing in the field, both early entry and conventional sawing times can be predicted for the range of mixtures tested.

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This report synthesizes the safety corridor programs of 13 states that currently have some type of program: Alaska, California, Florida, Kentucky, Minnesota, New Jersey, New Mexico, New York, Ohio, Oregon, Pennsylvania, Virginia, and Washington. This synthesis can help Midwestern states implement their own safety corridor programs and select pilot corridors or enhance existing corridors. Survey and interview information about the states’ programs was gathered from members of each state department of transportation (DOT) and Federal Highway Administration (FHWA) division office. Topics discussed included definitions of a safety corridor; length and number of corridors in the program; criteria for selection of a corridor; measures of effectiveness of an implemented safety corridor; organizational structure of the program; funding and legislation issues; and engineering, education, enforcement, and emergency medical service strategies. Safety corridor programs with successful results were then examined in more detail, and field visits were made to Kansas, Oregon, Pennsylvania, and Washington for first-hand observations. With the survey and field visit information, several characteristics of successful safety corridor programs were identified, including multidisciplinary (3E and 4E) efforts; selection, evaluation, and decommissioning strategies; organization structure, champions, and funding; task forces and Corridor Safety Action Plans; road safety audits; and legislation and other safety issues. Based on the synthesis, the report makes recommendations for establishing and maintaining a successful safety corridor program.

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The Tuttle Lake Watershed is approximately 125,000 acres and Tuttle Lake itself is 2,270 acres; 5,609 acres of the watershed lies in Iowa territory within Emmet County. It is a sub-watershed of the larger East Fork Des Moines River Watershed, also referred to as Hydrologic Unit Code 07100003. For the purpose of this document, grant money is only being applied for the project implementation in the Iowa portion of the Tuttle Lake Watershed. Tuttle Lake was placed on the 2002 EPA 303(d) Impaired Waters List due to a “very large population of suspended algae and very high levels of inorganic turbidity.” In 2004, the Iowa Department of Natural Resources (IDNR) completed a Total Maximum Daily Load (TMDL) study on Tuttle Lake and found excess sediment and phosphorus levels being the primary pollutants causing the algae and turbidity impairment. Although two point sources were located in Minnesota, IDNR determined that the influx of nutrients is likely from agricultural runoff and re-suspension of lake sediment. The condition of Tuttle Lake is such that the reduction of sediment, nutrients [phosphorus and nitrogen] and pathogens is the primary objective. To achieve that objective, wetlands will be constructed in this first phase to reduce the delivery of nitrogen, phosphorus, and sediment to Tuttle Lake.

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This report documents Phase III of a four-phase project. The goals of the project are to study the feasibility of using advanced technology from other industries to improve he efficiency and safety of winter highway maintenance vehicle operations, and to provide travelers with the level of service defined by policy during the winter season at the least cost to the taxpayers. The results of the first phase of the research were documented in the Concept Highway Maintenance Vehicle Final Report: Phase One dated April 1997, which describes the desirable functions of a concept maintenance vehicle and evaluates its feasibility. Phase I concluded by establishing the technologies that would be assembled and tested on the prototype vehicles in Phase II. The primary goals of phase II were to install the selected technologies on the prototype winter maintenance vehicles and to conduct proof of concept in advance of field evaluations planned for Phase III. This Phase III final report documents the work completed since the end of Phase II. During this time period, the Phase III work plan was completed and the redesigned friction meter was field tested. A vendor meeting was held to discuss future private sector participation and the new design for the Iowa vehicle. In addition, weather and roadway condition data were collected from the roadway weather information systems at selected sites in Iowa and Minnesota, for comparison to the vehicles' onboard temperature sensors. Furthermore, the team received new technology, such as the mobile Frensor unit, for bench testing and later installation.

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The Mississippi River Trail (MRT) is a world-class bicycle trail that will follow the Mississippi River all the way from its headwaters in Minnesota to the Gulf of Mexico. The trail is partially completed; much of it is still in the planning and development stages. When complete, the MRT will Link over 2,000 miles of recreational trails through 10 states, including 280 miles in Iowa. Designated as a National Millennium Trail, the MRT will preserve natural environments along the river, stimulate economic growth in river communities, and provide bicyclists access to a variety of landscapes, history, and culture. The Iowa Department of Transportation commissioned the Center for Transportation Research and Education at Iowa State University to develop a plan for a safe, economically beneficial, and scenic MRT route through Iowa. This report presents the MRT plan for Iowa. It is organized in the following chapters: Executive Summary; (1) Introduction - vision statement and objectives; (2) Iowa MRT Minimum Design Standards; (3) Iowa MRT Route Analysis; (4) Recommended Improvement Plan; (5) MRT Implementation; and (6) Estimated Benefits and Impacts of the Iowa MRT. Additional information is provided in the following appendices: (A) GIS Analysis for the MRT; (B) Iowa MRT Maps; (C) Public Input; (D) Public Comments; and (E) References.

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Waterloo Creek Watershed is a 30,610 acre area that straddles the Iowa and Minnesota border. The lower 43% of the watershed is in Iowa. Bee and Duck Creeks in Minnesota flow into Waterloo Creek in Iowa. Designated as a primary contact recreational stream as well as a high-quality, cold water stream in Iowa, Waterloo Creek is a popular destination for anglers and other nature enthusiasts. The stream was on the Iowa DNR’s “Impaired Waters List” in 2008 and 2010 for Escherichia coli (E. coli) bacteria. Samples collected in 2010 and 2011 showed higher levels of E. coli. at sites with cattle in close proximity to the stream and were generally greater after high rainfall events. Other factors affecting water quality are high turbidity levels and frequent flooding. There is a deficiency in upland land treatment and an abundance of conventional tillage which increases the amount of erosion and potential for surface runoff to carry sediment to the stream. A comprehensive watershed assessment and management plan have been completed for the watershed which identify the causes of and solutions to water quality impairments. The goals of this project are to 1) develop a formal working relationship between technical staff in Iowa and Minnesota, 2) identify specific locations for Best Management Practice (BMP) implementation, 3) reduce sediment loading to Waterloo Creek to improve aquatic habitat and decrease bacteria delivery, and 4) reduce flooding potential in the watershed. The following BMPs will be implemented to reach these goals: terraces, grade stabilization structures, pasture management, stream buffers, stream bank stabilization, and agricultural waste structures.

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The state Departments of Transportation (DOTs) of Iowa, Michigan, and Minnesota formed a consortium to define and develop the next generation highway maintenance vehicle. The Center for Transportation Research and Education of Iowa State University provided staff support to the concept highway maintenance vehicle project, which focused on winter maintenance activities. Phase I of the three-phase project focused on describing the desirable functions of a concept maintenance vehicle. Phase II will include the development, operation, and evaluation of prototype winter maintenance vehicles. Phase III is envisioned to be a comprehensive fleet evaluation of prototype winter maintenance vehicles. This report covers the activities of Phase I. Phase I included conducting a literature review of materials related to winter highway maintenance activities, identifying ideal capabilities of a winter maintenance vehicle, inviting private sector equipment and technology providers to join the project and commit equipment and expertise for Phase II, and determining the specific equipment and technology to be included on the three prototype vehicles for the winter of 1996-1997. Phase I concluded by establishing that assembling the three prototype vehicles would be beneficial to the project and to the three state DOTs.

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OBJECTIVE: - Clinical observations and a review of the literature led us to hypothesize that certain personality and character traits could provide improved understanding, and thus improved prevention, of suicidal behaviour among young women with eating disorders. METHOD: - The clinical group consisted of 152 women aged between 18 and 24 years, with DSM-IV anorexia nervosa/restrictive type (AN-R = 66), anorexia nervosa/purging type (AN-P = 37), bulimia nervosa/non-purging type (BN-NP = 9), or bulimia nervosa/purging type (BN-P = 40). The control group consisted of 140 subjects. The assessment measures were the Minnesota Multiphasic Personality Inventory-second version (MMPI-2) scales and subscales, the Beck Depression Inventory (BDI) used to control for current depressive symptoms, plus a specific questionnaire concerning suicide attempts. RESULTS: - Suicide attempts were most frequent in subjects with purging behaviour (30.0% for BN-P and 29.7% for AN-P). Those attempting suicide among subjects with eating disorders were mostly students (67.8%). For women with AN-R the scales for 'Depression' and 'Antisocial practices' represented significant suicidal risk, for women with AN-P the scales for 'Hysteria', 'Psychopathic deviate', 'Shyness/Self-consciousness', 'Antisocial Practices', 'Obsessiveness' and 'Low self-esteem' were risk indicators and for women with BN-P the 'Psychasthenia', 'Anger' and 'Fears' scales were risk indicators. CONCLUSION: - This study provides interesting results concerning the personality traits of young women with both eating disorders and suicidal behaviour. Students and those with purging behaviour are most at risk. Young women should be given more attention with regard to the risk of suicide attempts if they: (a). have AN-R with a tendency to self-punishment and antisocial conduct, (b). have AN-P with multiple physical complaints, are not at ease in social situations and have antisocial behaviour, or (c). if they have BN-P and tend to be easily angered with obsessive behaviour and phobic worries. The MMPI-2 is an interesting assessment method for the study of traits indicating a risk of suicidal behaviour in young subjects, after controlling for current depressive pathology.

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Unless effective preventive strategies are implemented, aging of the population will result in a significant worsening of the heart failure (HF) epidemic. Few data exist on whether baseline electrocardiographic (ECG) abnormalities can refine risk prediction for HF. METHODS: We examined a prospective cohort of 2,915 participants aged 70 to 79 years without preexisting HF, enrolled between April 1997 and June 1998 in the Health, Aging, and Body Composition (Health ABC) study. Minnesota Code was used to define major and minor ECG abnormalities at baseline and at year 4 follow-up. Using Cox models, we assessed (1) the association between ECG abnormalities and incident HF and (2) the incremental value of adding ECG to the Health ABC HF Risk Score using the net reclassification index. RESULTS: At baseline, 380 participants (13.0%) had minor, and 620 (21.3%) had major ECG abnormalities. During a median follow-up of 11.4 years, 485 participants (16.6%) developed incident HF. After adjusting for the Health ABC HF Risk Score variables, the hazard ratio (HR) was 1.27 (95% CI 0.96-1.68) for minor and 1.99 (95% CI 1.61-2.44) for major ECG abnormalities. At year 4, 263 participants developed new and 549 had persistent abnormalities; both were associated with increased subsequent HF risk (HR 1.94, 95% CI 1.38-2.72 for new and HR 2.35, 95% CI 1.82-3.02 for persistent ECG abnormalities). Baseline ECG correctly reclassified 10.5% of patients with HF events, 0.8% of those without HF events, and 1.4% of the overall population. The net reclassification index across the Health ABC HF risk categories was 0.11 (95% CI 0.03-0.19). CONCLUSIONS: Among older adults, baseline and new ECG abnormalities are independently associated with increased risk of HF. The contribution of ECG screening for targeted prevention of HF should be evaluated in clinical trials.