Insights into the Design and Characteristics of the Sedimentation Process at Multi-Barrel Culverts in Iowa, TR-596, 2010

The present study is an integral part of a broader study focused on the design and implementation of self-cleaning culverts, i.e., configurations that prevent the formation of sediment deposits after culvert construction or cleaning. Sediment deposition at culverts is influenced by many factors, including the size and characteristics of material of which the channel is composed, the hydraulic characteristics generated under different hydrology events, the culvert geometry design, channel transition design, and the vegetation around the channel. The multitude of combinations produced by this set of variables makes the investigation of practical situations a complex undertaking. In addition to the considerations above, the field and analytical observations have revealed flow complexities affecting the flow and sediment transport through culverts that further increase the dimensions of the investigation. The flow complexities investigated in this study entail: flow non-uniformity in the areas of transition to and from the culvert, flow unsteadiness due to the flood wave propagation through the channel, and the asynchronous correlation between the flow and sediment hydrographs resulting from storm events. To date, the literature contains no systematic studies on sediment transport through multi-box culverts or investigations on the adverse effects of sediment deposition at culverts. Moreover, there is limited knowledge about the non-uniform, unsteady sediment transport in channels of variable geometry. Furthermore, there are few readily useable (inexpensive and practical) numerical models that can reliably simulate flow and sediment transport in such complex situations. Given the current state of knowledge, the main goal of the present study is to investigate the above flow complexities in order to provide the needed insights for a series of ongoing culvert studies. The research was phased so that field observations were conducted first to understand the culvert behavior in Iowa landscape. Modeling through complementary hydraulic model and numerical experiments was subsequently carried out to gain the practical knowledge for the development of the self-cleaning culvert designs.

What the Law Requires: Accessible Multi-family Housing in Iowa, 2003

Booklet produced by the Iowa Civil Rights Commission for individuals who own, design, build, or develop multi-family housing.

Material and Construction Optimization for Prevention of Premature Pavement Distress in PCC Pavements, September 2004

The chemistry of today’s concrete mixture designs is complicated by many variables, including multiple sources of aggregate and cements and a plethora of sometimes incompatible mineral and chemical admixtures. Concrete paving has undergone significant changes in recent years as new materials have been introduced into concrete mixtures. Supplementary cementitious materials such as fly ash and ground granulated blast furnace slag are now regularly used. In addition, many new admixtures that were not even available a few years ago now have widespread usage. Adding to the complexity are construction variables such as weather, mix delivery times, finishing practices, and pavement opening schedules. Mixture materials, mix design, and pavement construction are not isolated steps in the concrete paving process. Each affects and is affected by the other in ways that determine overall pavement quality and long-term performance. Equipment and procedures commonly used to test concrete materials and concrete pavements have not changed in decades, leaving serious gaps in our ability to understand and control the factors that determine concrete durability. The concrete paving community needs tests that will adequately characterize the materials, predict interactions, and monitor the properties of the concrete.

On the Segregation of Genetically Modified, Conventional, and Organic Products in European Agriculture: A Multi-market Equilibrium Analysis, October 2005

Evaluating the possible benefits of the introduction of genetically modified (GM) crops must address the issue of consumer resistance as well as the complex regulation that has ensued. In the European Union (EU) this regulation envisions the “co-existence” of GM food with conventional and quality-enhanced products, mandates the labelling and traceability of GM products, and allows only a stringent adventitious presence of GM content in other products. All these elements are brought together within a partial equilibrium model of the EU agricultural food sector. The model comprises conventional, GM and organic food. Demand is modelled in a novel fashion, whereby organic and conventional products are treated as horizontally differentiated but GM products are vertically differentiated (weakly inferior) relative to conventional ones. Supply accounts explicitly for the land constraint at the sector level and for the need for additional resources to produce organic food. Model calibration and simulation allow insights into the qualitative and quantitative effects of the large-scale introduction of GM products in the EU market. We find that the introduction of GM food reduces overall EU welfare, mostly because of the associated need for costly segregation of non-GM products, but the producers of quality-enhanced products actually benefit.

Iowa Comprehensive Annual Financial Report, 2005

In accordance with Iowa Code Section 8A.502(8) we are pleased to submit the Comprehensive Annual Financial Report (CAFR) for the State of Iowa for the fiscal year ended June 30, 2005. The report is presented in three sections as follows: • The Introductory Section includes this transmittal letter, the Government Finance Officers Association (GFOA) Certificate of Achievement for the fiscal year 2004 CAFR, an organizational chart of State government, and a list of principal State officials. • The Financial Section contains the independent auditor’s report on the Basic Financial Statements, Management’s Discussion and Analysis (MD&A), the Basic Financial Statements, and Notes to the Financial Statements. The Financial Section also contains Required Supplementary Information (RSI), other than the MD&A, and supplementary information in the form of combining financial statements and schedules. This letter is intended to be read in conjunction with the MD&A. • The Statistical Section highlights selected financial and demographic information, generally presented on a multi-year basis. The Department of Administrative Services is responsible for both the accuracy of the presented data, and the completeness and fairness of the presentation. We believe the information presented is accurate in all material respects and the necessary disclosures have been made which enable the reader to obtain an understanding of the State’s financial activity. This report has been prepared in accordance with U.S. generally accepted accounting principles (GAAP) for governments as promulgated by the Governmental Accounting Standards Board (GASB). As a part of the statewide accounting system upgrade during fiscal year 2005, the implementation team performed a comprehensive review of the adequacy of internal controls and budgetary controls of the system. The team determined that internal controls continue to be in place to provide reasonable, but not absolute, assurance that assets are safeguarded against unauthorized use or disposition, and that financial records from all appropriate sources are reliable for preparing financial statements and maintaining accountability. The concept of reasonable assurance recognizes the cost of internal controls should not exceed the benefits likely to be derived from their use. To monitor the adequacy of internal controls, the Auditor of State reviews internal control procedures as an integral part of departmental audits.