                    Model Change Bulletin             
             
                            MCB#2                 7/9/13

                    VISCREEN (dated 13190)



	This Model Change Bulletin (MCB) documents changes
made to the VISCREEN Visibility Screening Model. A brief
description of the changes is provided below.  Additional
details are available in the Fortran source code and with
other documentation.

	Viscreen (88341) was recompiled after minor source
code changes and assigned the creation date above.  These
changes have been commented in lines above each respective
change and in the source code just below the SCRAM header. 
These changes have not affected the results.

	Previous output files have been processed through a
Lotus 1-2-3 spreadsheet using macros created with the Lotus
1-2-3 macro language.  Due to the EPA switching to Microsoft
based applications, the Lotus 1-2-3 spreadsheets and macros
were rewritten based on Microsoft Excel.  The macros were
reprogrammed using Visual Basic for Applications.  While
this Excel spreadsheet can be run using Open Source
applications, the macros may not be useable in those
applications

	A “courseware” introduction to Viscreen was rewritten
using most of the old Paint Shop Pro formatted graphics
(*.PCX) and translated into JPG formats and then inserted
into this introduction.  This introduction is available for
viewing in PDF and Microsoft PowerPoint versions. 

	The Workbook for Plume Visual Impact Screening and
Analysis was revised in October of 1992.  Minor changes were
made to this document such as processing the work book
through an Adobe based Optical Character Recognition program
and in straightening out three skewed figures.

	Other instructions were updated according to need.

If you have any issues, please use the SCRAM Web Site
Contact Us page at
http://www.epa.gov/ttn/scram/comments.htm.  Your comments
will be received and directed to a person who will be able
to reply to your issues.

                       ******************
                       * Important Note * 
                       ******************
  
      New Model Change Bulletins will ONLY be issued when there
is a change to the source code for this model. Changes to test
cases and/or any pre and post processors that are included in the
archived file for this model will be addressed and appropriately
identified in an amendment to the model's latest MCB with
notification posted in the SCRAM ALERTS section of the BBS.
