Welcome to Cranium !
Cranium is our physical property management and estimation software package. With Cranium, you can store physical property data, generate physical property estimates, capture property estimation knowledge, and diseminate property knowledge into reports, graphs, websites and other chemical software programs.
This page provides a quick tour of some of Cranium's capabilities. Because you will be creating new entities, entering data and estimating properties, it is very important that you create and use a copy of a knowledge base.
The Reader version of Cranium does not allow you to make copies of documents. If you are using the Reader version you can edit the original document. The Reader version does not save any changes.
Cranium will save a copy of the current knowledge base. Use the File menu's Open command to open this new copy.
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The 'mkskbd' extension denotes a Molecular Knowledge Systems Knowledge Base document. |
The Save a Copy command is useful for quickly making a backup of your current document. Before you make significant changes to a document, you should consider using the Save a Copy command to make a backup.
A knowledgebase is a compilation of information on elements, molecular structures, chemicals, mixtures, estimation techniques and references. Values for the properties of each entity are presented on a single "page" of the knowledge base. These entity pages are arranged into "chapters". The tabs at the top of each knowledge base window correspond to each of these chapters.
Since each entity is displayed on a separate page in a chapter, navigating through Cranium primarily involves changing chapters and turning pages. See documentation for the Navigation Menu for more details on navigation. For more details on the structure of a Cranium document see Cranium Documents.
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Click on a tab at the top of a window to change chapters. |
The navigation controls located in the toolbar enable you to page through all the entities within a chapter.
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Move to the chapter's first page. |
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Move to the chapter's previous page. |
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Move to the chapter's next page. |
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Move to the chapter's last page. |
All three methods are equivalent and result in the display of the next chemical stored in the knowledge base. Navigating to the previous chemical is done by either pressing the toolbar’s left facing, hollow arrow, choosing the Navigation menu’s Page Back command or pressing the ctrl-B accelerator keystroke.
At a chapter’s first page, the commands for paging backward will be disabled. Likewise, at the chapter’s last page, the commands for paging forward will be disabled.
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Attribute, e.g., identifier, synonym, etc., displayed for selection. |
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List of entities containing the selection substrings shown below. |
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Only entities containing this substring are displayed. |
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Only entities containing this substring are displayed. |
One of Cranium’s key capabilities is to estimate physical properties quickly, easily and accurately. To estimate a property Cranium first collects all applicable techniques, sorts them by accuracy, and then tries each one until an estimate is generated.
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Control showing the detailed results of the estimation. |
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Column of data values. |
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Column of estimated values. |
Change the Estimation Mode to Manual Mode and select the Joback Method. (Note: the actutal techniques used and available may differ depending upon the knowledge base you are using. The key concept for this example, is to choose a different technique than the one Cranium automatically selected.)
Cranium also estimates temperature and pressure dependent properties. To estimate such dependent properties, you must first enter temperature and pressure values.
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Property control. |
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Values type control. |
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Field's table control. |
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Properties list control. |
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Values type control. |
Temperature dependent estimates can now be generated as done previously. However, for this example you will only generate vapor pressure estimates.
One of the advantages of an electronic reference book over a printed one is the ease with which pages can be added and removed.
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Add Button: pressing this toolbar button will add a new, blank page to the current chapter. |
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Delete Button: pressing this toolbar button will delete the current page from the current chapter. IMPORTANT: the deletion of a page cannot be undone. |
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Identifier's field data control. |
Many estimation techniques require knowledge of a chemical's molecular structure. Some techniques require only information about the chemical's family, e.g., is the chemical chlorinated. Other techniques, e.g., group contribution techniques, require a chemical's structure to be completely dissected into molecular fragments.
Cranium uses a simple connectivity model to represent molecular structure. Atoms and bonds are connected into a simple graph.
The tool buttons on the dialog's left are used to change drawing modes. The controls at the dialog’s top are used to specify the current element and the current bond type. The large central window is the canvas on which you draw your structure.
You can now use the Commands menu Compute Estimates command to estimate the properties of the new structure.
Topic | Description |
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Estimating Chemical Properties | a short video demonstrating how to estimate the physical properties of chemicals using either Synapse or Cranium. |
Estimating Mixture Properties | a short video demonstrating how to estimate the physical properties of mixtures using either Synapse or Cranium. |
Getting Started using Synapse | provides a quick tour of Synapse's capabilities including examples of chemical product design. |