Report on the Iowa Lottery Authority for the period July 1, 2002 through June 30, 2010

Report on the Iowa Lottery Authority for the period July 1, 2002 through June 30, 2010

Agreed upon procedures report on the Iowa Sheep and Wool Promotion Board for the period July 1, 2009 through June 30, 2011

Agreed upon procedures report on the Iowa Sheep and Wool Promotion Board for the period July 1, 2009 through June 30, 2011

Report on a review of selected application controls over the Iowa Department of Transportation’s Driver’s License System for the period May 2, 2011 through May 27, 2011

Report on a review of selected application controls over the Iowa Department of Transportation’s Driver’s License System for the period May 2, 2011 through May 27, 2011

Report on a special investigation of the Sunrise Sunset Daycare of the Southeast Warren Community School District for the period September 1, 2010 through September 26, 2011

Report on a special investigation of the Sunrise Sunset Daycare of the Southeast Warren Community School District for the period September 1, 2010 through September 26, 2011

Report on a review of selected application controls over the Iowa State University of Science and Technology Facilities Planning and Management - Facilities Administrative Management Information System for the period of April 18, 2011 through May 16, 2011

Report on a review of selected application controls over the Iowa State University of Science and Technology Facilities Planning and Management - Facilities Administrative Management Information System for the period of April 18, 2011 through May 16, 2011

Flow structures at an idealized bifurcation : a numerical experiment

River bifurcations are key nodes within braided river systems controlling the flow and sediment partitioning and therefore the dynamics of the river braiding process. Recent research has shown that certain geometrical configurations induce instabilities that lead to downstream mid-channel bar formation and the formation of bifurcations. However, we currently have a poor understanding of the flow division process within bifurcations and the flow dynamics in the downstream bifurcates, both of which are needed to understand bifurcation stability. This paper presents results of a numerical sensitivity experiment undertaken using computational fluid dynamics (CFD) with the purpose of understanding the flow dynamics of a series of idealized bifurcations. A geometric sensitivity analysis is undertaken for a range of channel slopes (0.005 to 0.03), bifurcation angles (22 degrees to 42 degrees) and a restricted set of inflow conditions based upon simulating flow through meander bends with different curvature on the flow field dynamics through the bifurcation. The results demonstrate that the overall slope of the bifurcation affects the velocity of flow through the bifurcation and when slope asymmetry is introduced, the flow structures in the bifurcation are modified. In terms of bifurcation evolution the most important observation appears to be that once slope asymmetry is greater than 0.2 the flow within the steep bifurcate shows potential instability and the potential for alternate channel bar formation. Bifurcation angle also defines the flow structures within the bifurcation with an increase in bifurcation angle increasing the flow velocity down both bifurcates. However, redistributive effects of secondary circulation caused by upstream curvature can very easily counter the effects of local bifurcation characteristics. Copyright (C) 2011 John Wiley & Sons, Ltd.

Report on a special investigation of the Starmont Community School District for the period July 1, 1993 through November 30, 2010

Report on a special investigation of the Starmont Community School District for the period July 1, 1993 through November 30, 2010

Report on a review of selected general and application controls over the Iowa Department of Human Services’ Medicaid Management Information System for the period April 4, 2011 through April 29, 2011

Report on a review of selected general and application controls over the Iowa Department of Human Services’ Medicaid Management Information System for the period April 4, 2011 through April 29, 2011

Agreed upon procedures report on the six Library Service Areas in the State of Iowa for the period July 1, 2010 through June 30, 2011

Agreed upon procedures report on the six Library Service Areas in the State of Iowa for the period July 1, 2010 through June 30, 2011

Agreed upon procedures report on the Lee County Narcotics Task Force for the period July 1, 2010 through May 31, 2012

Agreed upon procedures report on the Lee County Narcotics Task Force for the period July 1, 2010 through May 31, 2012

Special investigation of the City of Scarville for the period January 1, 2006 through March 31, 2011

Special investigation of the City of Scarville for the period January 1, 2006 through March 31, 2011

Report on applying agreed-upon procedures of Kossuth Connections, Algona, Iowa, and the Iowa Commission on Volunteer Services within the Iowa Department of Economic Development, now known as the Iowa Economic Development Authority, for the period October 2010 through June 2011

Report on applying agreed-upon procedures of Kossuth Connections, Algona, Iowa, and the Iowa Commission on Volunteer Services within the Iowa Department of Economic Development, now known as the Iowa Economic Development Authority, for the period October 2010 through June 2011

Report on the Chariton Valley Planning & Development Council of Governments for the period July 1, 2007 through August 31, 2010

Report on the Chariton Valley Planning & Development Council of Governments for the period July 1, 2007 through August 31, 2010

Report on a special investigation of the City of Bloomfield Volunteer Fire Department for the period July 1, 2006 through June 30, 2010

Report on a special investigation of the City of Bloomfield Volunteer Fire Department for the period July 1, 2006 through June 30, 2010

Report on a special investigation of the Mills County Treasurer’s Office for the period January 1, 2005 through March 31, 2011

Report on a special investigation of the Mills County Treasurer’s Office for the period January 1, 2005 through March 31, 2011