997 resultados para Wood construction


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Borrow areas are created where soil is removed to provide needed fill material for highway and other construction projects. Where these areas are located beyond the highway right-of-way, they must be restored and returned to useful purposes. In Iowa, borrow areas are often developed on agricultural lands and therefore, it is necessary to return them to agricultural uses whenever possible. This research project was established to evaluate the changes in row crop productivity where borrow is removed for highway construction. Secondly, several reclamation techniques were selected to be applied to borrow area research sites and the response of crops to each treatment will be evaluated. All borrow area research sites were selected in 1977 from Iowa Department of Transportation construction plans. The Audubon and Buchanan County sites were completed in the fall of 1977 and May 1978, respectively. Both were used for research in 1978, 1979, and 1980. The two remaining sites in Hamilton and Lee Counties were completed in the fall of 1978 and research was conducted at these sites in 1979, 1980, and 1981. In this report, the 1981 results from the Hamilton and Lee County borrow sites will be presented. Secondly, a summary of the three years of research from each borrow area will be presented along with specific and general conclusions from the research project.

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This paper presents the preliminary findings of pH and colour measurements carried out on artworks on paperand on wood that had been treated with a poly(vinyl acetate) (PVAC) based adhesive in the 1980s. In both cases, areas treated with PVAC proved to be less acidic than untreated areas. Contrary to expectations, the conservation treatments have not, as yet, increased acidity levels in the objects under study. Colour measurements of the works on paper showed that those that had been backed with a cotton fabric using a mixture of methylcellulose and PVAC were less yellow than those from the same print run that had not been backed. This finding suggests that the backing somehow prevented the natural degradation of the support. In view of these preliminary results, further research is clearly needed. This study forms part of a broader ongoing project to assess the role of PVAC in the conservation of a range of cultural assets.

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The purpose of this study is to provide recommendations relative to the location and construction needs for highway maintenance facilities within the state of Iowa. These recommendations were to be developed with consideration being given to the public's expectations and priorities for highway maintenance services. As a part of the study effort, a review was made of the methods used by other states to deliver highway maintenance services. To accomplish the study, Wilbur Smith Associates undertook a series of tasks. These efforts included gathering of data and information to characterize the various maintenance programs and the delivery of maintenance and operations services by the Department. We researched the delivery of highway maintenance services in other states. Interviews with Iowa DOT maintenance personnel were accomplished. A schedule of public hearings was developed and ten hearings were held. All the information was integrated and various analyses were made. From these analyses we drew conclusions and developed recommendations.

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This document produced bu Iowa State University and Iowa Department of Natural Resources shows the key identification of Common Woods in Iowa.

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When referenced, the 2012 edition of the Iowa Department of Transportation’s (Iowa DOT) Standard Specifications for Highway and Bridge Construction shall be used for contract work awarded by the Iowa DOT. They may also be incorporated by reference in other contract work on secondary, urban, local systems, or other contract work in which the Iowa DOT has an interest. As modified by the General Supplemental Specifications, these Standard Specifications represent the minimum requirements and may be modified by Supplemental Specifications, Developmental Specifications, and Special Provisions on specific contracts. These Standard Specifications have been written so the Contractor’s responsibilities are indicated by plain language using the Imperative Mood and Active Voice form. Sentences are of the form: Construct isolation joints at all points where driveways meet other walks, curbs, or fixtures in the surface. Ensure finished members are true to detailed dimensions and free from twists, bends, open joints, or other defects resulting from faulty fabrication or defective work. Personnel preparing the JMF shall be Iowa DOT certified in bituminous mix design. The Contracting Authority’s responsibilities are (with some exceptions) indicated by the use of the modal verb “will”. Sentences are of the form: The Engineer will obtain and test density samples for each lot according to Materials I.M. 204. Payment will be the contract unit price for Fabric Reinforcement per square yard (square meter). These standard specifications contain dual units of measure: the United States Standard measure (English units) and the International System of Units (SI or “metric” units). The English units are expressed first then followed by the metric units in parentheses. The measurements expressed in the two systems are not necessarily equal. In some cases the measurements in metric units is a “hard” conversion of the English measurement; i.e. the metric unit has been approximated with a rounded, rationalized metric measurement that is easy to work with and remember. The proposal form will identify whether the work was designed and shall be constructed in English or metric units.

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The Rock Island Centennial Bridge spanning the Mississippi River between Rock Island, Illinois and Davenport, Iowa was opened to traffic on July 12, 1940. It is a thoroughly modern, four-lane highway bridge, adequate in every respect for present day high speed passenger and transport traffic. The structure is ideally situated to provide rapid transit between the business districts of Rock Island and Davenport and serves not only the local or shuttle traffic in the Tri-City Area, but also heavy through motor travel on U.S. Highways 67 and 150. The Centennial Bridge is notable in several respects. The main spans are box girder rib tied arches, a type rather unusual in America and permitting simplicity in design with pleasing appearance. The Centennial Bridge is the only bridge across the Mississippi providing for four lanes of traffic with separation of traffic in each direction. It is a toll bridge operating alongside a free bridge and has the lowest rates of toll of any toll bridge on the Mississippi River. It was financed entirely by the City of Rock Island with no obligation on the taxpayers; there was no federal or state participation in the financing. But perhaps the most outstanding feature of the new bridge is its great need. A few remarks on the communities served by the new structure, the services rendered, and some statistics on cross-river traffic in the Tri-City Area will emphasize the reasons for constructing the Centennial Bridge.

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1. Wood ants (Formica paralugubris) incorporate large amounts of solidified conifer resin into their nest, which reduces the density of many bacteria and fungi and protects the ants against some detrimental micro-organisms. By inducing an environment unfavourable to pathogens, the presence of resin may allow workers to reduce the use of their immune system. 2. The present study tested the hypothesis that the presence of resin decreases the immune activity of wood ants. Specifically, three components of the humoral immune defences of workers kept in resin-rich and resin-free experimental nests (antibacterial, lytic, and prophenoloxidase activities) were compared. 3. The presence of resin was associated with reduced bacterial and fungal densities in nest material and with a small decrease in worker antibacterial and lytic activities. The prophenoloxidase activity was very low in all workers and was not affected by the presence of resin. 4. These results suggest that collective medication with resin reduces pathogen pressure, which in turn decreases the use of the inducible part of the immune system. More generally, the use of plant secondary compounds might be an efficient and economical way to fight pathogens.

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Iowa’s three million acres of forest land provide environmental benefits to all Iowans in terms of soil erosion control, air quality, and water quality. In 2013, more than 6.5 million trees died. Within those trees there were more than 125 million board feet of wood, compared to 98 million board feet of wood harvested. This level of mortality is the highest level reported from US Forest Service inventories in twenty years. This is disturbing when considering more than 18,000 Iowans are employed in the wood products and manufacturing industry, generating nearly $4 billion in annual sales, more than $900 million in annual payroll and more than $25 million to private woodland owners annually from the sale of timber.

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This report describes the highway construction program, actual expenditures of the program and contractual obligations of the program for FY 2014.

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The aim of this study is to identify cognitive variables that predict disordered eating attitudes in a nonclinical sample composed of 50 female university students. Repertory grid technique was used to assess cognitive features of self-construing and cognitive conflicts. Drive for Thinness and Body Dissatisfaction scales from the Eating Disorder Inventory 2 were used as dependent variables, as previous studies suggested that high scores on these scales are associated with the risk of developing or aggravating eating syndromes. Results suggest that drive for thinness can be associated with cognitive conflicts, whereas body dissatisfaction may be higher for those who construct themselves as inadequate and similar to others. In addition, both dependent variables were predicted by being younger and having a higher body mass index.

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Capacity is affected by construction type and its intensity on adjacent open traffic lanes. The effect on capacity is a function of vehicles moving in and out of the closed lanes of the work zone, and the presence of heavy construction vehicles. Construction activity and its intensity, however, are not commonly considered in estimating capacity of a highway lane. The main purpose of this project was to attempt to quantify the effects of construction type and intensity (e.g. maintenance, rehabilitation, reconstruction, and milling) on work zone capacity. The objective of this project is to quantify the effects of construction type and its intensity on work zone capacity and to develop guidelines for MoDOT to estimate the specific operation type and intensity that will improve the traffic flow by reducing the traffic flow and queue length commonly associated with work zones. Despite the effort put into field data collection, the data collected did not show a full speed-flow chart therefore extracting a reliable capacity value was difficult. A statistical comparison between the capacity values found in this study using either methodologies indicates that there is an effect of construction activity on the values work zone capacity. It was found that the heavy construction activity reduces the capacity. It is very beneficial to conduct similar studies on the capacity of work zone with different lane closure barriers, which is also directly related to the type of work zone being short-term or long-term work zones. Also, the effect of different geometric and environmental characteristics of the roadway should be considered in future studies.

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This phase of the research project involved two major efforts: (1) Complete the implementation of AEC-Sync (formerly known as Attolist) on the Iowa Falls Arch Bridge project and (2) develop a web-based project management system (WPMS) for projects under $10 million. For the first major effort, AEC-Sync was provided for the Iowa Department of Transportation (DOT) in a software as a service agreement, allowing the Iowa DOT to rapidly implement the solution with modest effort. During the 2010 fiscal year, the research team was able to help with the implementation process for the solution. The research team also collected feedback from the Broadway Viaduct project team members before the start of the project and implementation of the solution. For the 2011 fiscal year, the research team collected the post-project surveys from the Broadway Viaduct project members and compared them to the pre-project survey results. The result of the AEC-Sync implementation in the Broadway Viaduct project was a positive one. The project members were satisfied with the performance of AEC-Sync and how it facilitated document management and transparency. In addition, the research team distributed, collected, and analyzed the pre-project surveys for the Iowa Falls Arch Bridge project. During the 2012 fiscal year, the research team analyzed the post-project surveys for the Iowa Falls Arch Bridge project AEC-Sync implementation and found a positive outcome when compared to the pre-project surveys. The second major effort for this project involved the identification and implementation of a WPMS solution for smaller bridge and highway projects. During the 2011 fiscal year, Microsoft SharePoint was selected to be implemented on these smaller highway projects. In this year, workflows for the shop/working drawings for the smaller highway projects specified in Section 1105 of the Iowa DOT Specifications were developed. These workflows will serve as the guide for the development of the SharePoint pages. In order to implement the Microsoft SharePoint pages, the effort of an integrated team proved to be vital because it brought together the expertise required from researchers, programmers, and webpage developers to develop the SharePoint pages.