Sign in as Different User 

C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\15\TEMPLATE\CONTROLTEMPLATES\welcome.aspx

<SharePoint:MenuItemTemplate runat="server" ID="ID_LoginAsDifferentUser"

  Text="<%$Resources:wss,personalactions_loginasdifferentuser%>"

  Description="<%$Resources:wss,personalactions_loginasdifferentuserdescription%>"

  MenuGroupId="100"

  Sequence="100"

  UseShortId="true"  />

Export to Excel After Page is Refresh using C#

   //sharepoint postback to work after clicking on export to excel button

<script type="text/javascript" language="javascript">     if (typeof (_spBodyOnLoadFunctionNames) != 'undefined' &&                                           _spBodyOnLoadFunctionNames != null) {        _spBodyOnLoadFunctionNames.push("supressSubmitWraper");    }    function supressSubmitWraper() {
        _spSuppressFormOnSubmitWrapper = true;
    }</script>