EXHIBIT 3.79
                                                                    ------------

                           ARTICLES OF INCORPORATION
                                       OF
                   ADVANCED ANALYTICAL SOLUTIONS INCORPORATED

KNOW ALL MEN BY THESE PRESENTS:

     That the undersigned incorporator being a natural person of the age of
eighteen years or more and desiring to form a body corporate under the laws of
the State of Colorado does hereby sign, verify and deliver in duplicate to the
Secretary of State of the State of Colorado, these Articles of Incorporation:

                                   ARTICLE I
                                   ---------
                                      NAME
                                      ----

     The name of the corporation shall be:  Advanced Analytical Solutions
Incorporated.

                                   ARTICLE II
                                   ----------
                               PERIOD OF DURATION
                               ------------------

     The corporation shall exist in perpetuity, from and after the date of
filing these Articles of Incorporation with the Secretary of State of the State
of Colorado unless dissolved according to law.

                                  ARTICLE III
                                  -----------
                              PURPOSES AND POWERS
                              -------------------

     1.  Purposes.  Except as restricted by these Articles of Incorporation, the
         --------
corporation is organized for the purpose of transacting all lawful business for
which corporations may be incorporated pursuant to the Colorado Corporation
Code.

     2.  General Powers.  Except as restricted by these Articles of
         --------------
Incorporation, the corporation shall have and may exercise all powers and rights
which a corporation may exercise legally pursuant to the Colorado Corporation
Code.

                                   ARTICLE IV
                                   ----------
                                 CAPITAL STOCK
                                 -------------

     1.  Capital Stock.  The aggregate number of shares which this corporation
         -------------
shall have authority to issue is two hundred thousand (200,000) shares of a par
value of ($.25 per share) which shares shall be designated "Common Stock" and
one hundred thousand (100,000) shares of a par value of ($1.00 per share) which
shares shall be designated "Preferred Stock".  Both the Common Stock and
Preferred Stock may be subdivided and issued in series pursuant to resolutions
of the board of directors containing such designations, limitations, rights and
preferences which the board of directors, in its sole discretion, may determine
to be appropriate.


     2.  Dividends.  Dividends in cash, property or shares of the corporation
         ---------
may be paid upon the Common Stock and the Preferred Stock as and when declared
by the board of directors in conformance with the resolutions of the board of
directors authorizing the issuance of the stock, to the extent and in the manner
permitted by law; provided however, no Common Stock dividend shall be paid for
any year unless the holders of Preferred Stock, if any, shall have received any
Preferred Stock preferential dividends, if any, to which they are entitled.

     3.  Distribution in Liquidation.  Upon any liquidation, dissolution or
         ---------------------------
winding up of the corporation, and after paying or adequately providing for the
payment of all its obligations, the remainder of the assets of the corporation
shall be distributed, either in cash or in kind, in the order provided herein.
Such distributions shall be made first, to the holders of the Preferred Stock
until any amounts required to be distributed as a liquidation preference to the
holders of the Preferred Stock have been distributed.  If the remainder of the
assets is insufficient to fully satisfy the liquidation preference(s) of the
Preferred Stock, then those assets shall be distributed pro rata to each series
of Preferred Stock beginning with the series having the most superior
liquidation preference and continuing according to the liquidation preference
priority of each series until the remaining assets have been fully distributed.
Second, the assets remaining after satisfaction of the liquidation preference(s)
of the Preferred Stock shall be distributed pro rata to the holders of the
Common Stock, unless otherwise provided in the resolutions of the board of
directors authorizing the issuance of the Common Stock in series, in which case
the priority for distribution in liquidation established in those resolutions
shall be followed.

     4.  Voting Rights; Cumulative Voting.  Each outstanding share of Common
         --------------------------------
Stock shall be entitled to one vote and each fractional share of Common Stock
shall be entitled to a corresponding fractional vote on each matter submitted to
a vote of shareholders.  Two-thirds of the shares entitled to vote, represented
in person or by proxy, shall constitute a quorum at a meeting of shareholders.
Cumulative voting shall not be allowed in the election of directors of the
corporation.  Except as otherwise provided by these Articles of Incorporation or
the Colorado Corporation Code, if a quorum is present, the affirmative vote of
two-thirds of the shares represented at the meeting and entitled to vote on the
subject matter shall be the act of the shareholders.

     5.  Denial of Preemptive Rights.  No holder of any shares of the
         ---------------------------
corporation, whether now or hereafter authorized, shall have any preemptive or
preferential right to acquire any shares or securities of the corporation,
including shares or securities held in the treasury of the corporation.

     6.  Transfer Restrictions.  The corporation shall have the right to impose
         ---------------------
restrictions upon the transfer of any of its authorized shares or any interest
therein.  The board of directors is hereby authorized on behalf of the
corporation to exercise the corporation's right to so impose such restrictions.

                                       2


                                   ARTICLE V
                                   ---------
                     TRANSACTIONS WITH INTERESTED DIRECTORS
                     --------------------------------------

     No contract or other transaction between the corporation and one or more of
its directors or any other corporation, partnership, firm, association, or
entity in which one or more of its directors are directors or officers or are
financially interested shall be either void or voidable solely because of such
relationship or interest or solely because such directors are present at or
participate in the meeting of the board of directors or a committee thereof
which authorizes, approves, or ratifies such contract or transaction or solely
because their votes are counted for such purpose if:

          (a) The material facts of such relationship or interest and as to the
     contract or transaction are disclosed or are known to the board of
     directors or committee which in good faith authorizes, approves, or
     ratifies the contract or transaction by an affirmative vote of a majority
     of the disinterested directors even though the disinterested directors are
     less than a quorum, or consent sufficient for the purpose; or

          (b) The material facts of such relationship or interest and as to the
     contract or transaction are disclosed or are known to the shareholders
     entitled to vote and the shareholders specifically authorize, approve, or
     ratify in good faith such contract or transaction by an affirmative vote or
     by written consent; or

          (c) The contract or transaction was fair and reasonable to the
     corporation.

     Common or interested directors may be counted in determining the presence
of a quorum at a meeting of the board of directors or a committee thereof which
authorizes, approves, or ratifies such contract or transaction.

                                   ARTICLE VI
                                   ----------
                             CORPORATE OPPORTUNITY
                             ---------------------

     The officers, directors and other members of management of this corporation
shall be subject to the doctrine of "corporate opportunities" only insofar as it
applies to business opportunities in which this corporation has expressed an
interest as determined from time to time by this corporation's board of
directors as evidenced by resolutions appearing in the corporation's minutes.
Once such areas of interest are delineated, all such business opportunities
within such areas of interest which come to the attention of the officers,
directors, and other members of management of this corporation shall be
disclosed promptly to this corporation and made available to it.  The board of
directors may reject any business opportunity presented to it and thereafter any
officer, director or other member of management may avail himself of such
opportunity.  Until such time as this corporation, through its board of
directors, has designated an area of interest, the officers, directors and other
members of management of this corporation shall be free to engage in such areas
of interest on their own and this doctrine shall not limit the rights of any
officer, director or other member of management of this corporation to continue
a business existing prior to the time that such area of interest is designated
by the corporation.  This provision shall not be construed to release any
employee of this corporation (other than an

                                       3


officer, director or member of management) from any duties which he may have to
this corporation.

                                  ARTICLE VII
                                  -----------
                  INDEMNIFICATION AND LIMITATION OF LIABILITY
                  -------------------------------------------

     1.  Definitions.  The following definitions shall apply to the terms as
         -----------
used in this Article:

          A.  "Corporation" includes this corporation, and, in addition, for
purposes of this Article, references to "the corporation" shall also include any
constituent corporation (including any constituent of a constituent) absorbed in
a consolidation or merger which, if its separate existence had continued, would
have had power and authority to indemnify its directors, officers, and employees
or agents, so that any person who is or was a director, officer, employee or
agent of such constituent corporation, or is or was serving at the request of
such constituent corporation as a director, officer, employee or agent of
another corporation, partnership, joint venture, trust or other enterprise,
shall stand in the same position under this Article with respect to the
resulting or surviving corporation as he would have with respect to such
constituent corporation if its separate existence had continued.

          B.  "Director" means an individual who is or was a director of the
corporation and an individual who, while a director of the corporation, is or
was serving at the corporation's request as a director, officer, partner,
trustee, employee, or agent of any other foreign or domestic corporation or of
any partnership, joint venture, trust, other enterprise, or employee benefit
plan.  A director shall be considered to be serving an employee benefit plan at
the corporation's request if his or her duties to the corporation also impose
duties on or otherwise involve services by him or her to the plan or to
participants in or beneficiaries of the plan.  "Director" includes, unless the
context otherwise requires, the estate or personal representative of a director.

          C.  "Expenses" includes attorney fees.

          D.  "Liability" means the obligation to pay a judgment, settlement,
penalty, fine (including an excise tax assessed with respect to an employee
benefit plan), or reasonable expense incurred with respect to a proceeding.

          E.  "Official capacity", when used with respect to a director, means
the office of director in the corporation, and, when used with respect to a
person other than a director, means the office in the corporation held by the
officer or the employment or agency relationship undertaken by the employee or
agent on behalf of the corporation.  "Official capacity" does not include
service for any other foreign or domestic corporation or for any partnership,
joint venture, trust, other enterprise, or employee benefit plan.

          F.  "Party" includes an individual who was, is, or is threatened to be
made a named defendant or respondent in a proceeding.

                                       4


          G.  "Proceeding" means any threatened, pending, or completed action,
suit, or proceeding, whether civil, criminal, administrative, or investigative
and whether formal or informal.

     2.  Permissive Indemnification for Liability.
         ----------------------------------------

          A.  Except as provided in paragraph D of this Section 2, the
corporation may indemnify against liability incurred in any proceeding an
individual made a party to the proceeding because he or she is or was a director
if:

          i.  He or she conducted himself or herself in good faith;

          ii.  He or she reasonably believed:

               a.  In the case of conduct in his or her official capacity with
               the corporation, that his or her conduct was in the corporation's
               best interests; or

               b.  In all other cases, that his or her conduct was at least not
               opposed to the corporation's best interests; and

          iii. In the case of any criminal proceeding, he or she had no
          reasonable cause to believe his or her conduct was unlawful.

          B.  A director's conduct with respect to an employee benefit plan for
a purpose he or she reasonably believed to be in the interests of the
participants in or beneficiaries of the plan is conduct that satisfies the
requirements of this Section 2.  A director's conduct with respect to an
employee benefit plan for a purpose that he or she did not reasonably believe to
be in the interests of the participants in or beneficiaries of the plan shall be
deemed not to satisfy the requirements of this Section 2.

          C.  The termination of any proceeding by judgment, order, settlement,
or conviction, or upon a plea of nolo contendere or its equivalent, is not of
itself determinative that the individual did not meet the standard of conduct
set forth in paragraph A of this Section 2.

          D.  The corporation may not indemnify a director under this Section 2
either:

          i.  In connection with a proceeding by or in the right of the
          corporation in which the director was adjudged liable to the
          corporation; or

          ii.  In connection with any proceeding charging improper personal
          benefit to the director, whether or not involving action in his or her
          official capacity, in which he or she was adjudged liable on the basis
          that personal benefit was improperly received by him or her.

                                       5


          E.  Indemnification permitted under this Section 2 in connection with
a proceeding by or in the right of the corporation is limited to reasonable
expenses incurred in connection with the proceeding.

      3.  Mandatory Indemnification.
          -------------------------

          A.  Except as limited by these Articles of Incorporation, the
corporation shall be required to indemnify a director of the corporation who was
wholly successful, on the merits or otherwise, in defense of any proceeding to
which he or she was a party against reasonable expenses incurred by him or her
in connection with the proceeding.

          B.  Except as otherwise limited by these Articles of Incorporation, a
director who is or was a party to a proceeding may apply for indemnification to
the court conducting the proceeding or to another court of competent
jurisdiction.  On receipt of an application, the court, after giving any notice
the court considers necessary, may order indemnification in the following
manner:

          i.  If it determines the director is entitled to mandatory
          indemnification under paragraph A of this Section 3, the court shall
          order indemnification, in which case the court shall also order the
          corporation to pay the director's reasonable expenses incurred to
          obtain court-ordered indemnification.

          ii.  If it determines that the director is fairly and reasonably
          entitled to indemnification in view of all the relevant circumstances,
          whether or not he or she met the standard of conduct set forth in
          paragraph A of Section 2 of this Article or was adjudged liable in the
          circumstances described in paragraph D of Section 2 of this Article,
          the court may order such indemnification as the court deems proper;
          except that the indemnification with respect to any proceeding in
          which liability shall have been adjudged in the circumstances
          described in paragraph D of Section 2 of this Article is limited to
          reasonable expenses incurred.

      4.  Limitation on Indemnification.
          -----------------------------

          A.  The corporation may not indemnify a director under Section 2 of
this Article unless authorized in the specific case after a determination has
been made that indemnification of the director is permissible in the
circumstances because he or she has met the standard of conduct set forth in
paragraph A of Section 2 of this Article.

          B.  The determination required to be made by paragraph A of this
Section 4 shall be made:

          i.  By the board of directors by a majority vote of a quorum, which
          quorum shall consist of directors not parties to the proceeding; or

                                       6


          ii.  If a quorum cannot be obtained, by a majority vote of a committee
          of the board designated by the board, which committee shall consist of
          two or more directors not parties to the proceeding; except that
          directors who are parties to the proceeding may participate in the
          designation of directors for the committee.

          C.  If the quorum cannot be obtained or the committee cannot be
established under paragraph B of this Section 4, or even if a quorum is obtained
or a committee designated if such quorum or committee so directs, the
determination required to be made by paragraph A of this Section 4 shall be
made:

          i.  By independent legal counsel selected by a vote of the board of
          directors or the committee in the manner specified in subparagraph (i)
          or (ii) of paragraph B of this Section 4 or, if a quorum of the full
          board cannot be obtained and a committee cannot be established, by
          independent legal counsel selected by a majority vote of the full
          board; or

          ii.  By the shareholders.

          D.  Authorization of indemnification and evaluation as to
reasonableness of expenses shall be made in the same manner as the determination
that indemnification is permissible; except that, if the determination that
indemnification is permissible is made by independent legal counsel,
authorization of indemnification and evaluation as to reasonableness of expenses
shall be made by the body that selected said counsel.

      5.  Advance Payment of Expenses.
          ---------------------------

          A.  The corporation may pay for or reimburse the reasonable expenses
incurred by a director who is a party to a proceeding in advance of the final
disposition of the proceeding if:

          i.  The director furnishes the corporation with a written affirmation
          of his or her good-faith belief that he or she has met the standard of
          conduct described in subparagraph (i) of paragraph A of Section 2 of
          this Article;

          ii.  The director furnishes the corporation with a written
          undertaking, executed personally or on his or her behalf, to repay the
          advance if it is determined that he or she did not meet such standard
          of conduct; and

          iii.  A determination is made that the facts then known to those
          making the determination would not preclude indemnification under this
          Section 5.

          B.  The undertaking required by subparagraph (ii) of paragraph A of
this Section 5 shall be an unlimited general obligation of the director but need
not be secured and may be accepted without reference to financial ability to
make repayment.

                                       7


         C.  Determinations and authorizations of payments under this Section 5
shall be made in the manner specified in Section 4 of this Article.

     6.  Reimbursement of Witness Expenses.  The corporation shall pay or
         ---------------------------------
reimburse expenses incurred by a director in connection with his or her
appearance as a witness in a proceeding at a time when he or she has not been
made a named defendant or respondent in the proceeding.

     7.  Insurance for Indemnification.  The corporation may purchase and
         -----------------------------
maintain insurance on behalf of a person who is or was a director, officer,
employee, fiduciary, or agent of the corporation or who, while a director,
officer, employee, fiduciary, or agent of the corporation, is or was serving at
the request of the corporation as a director, officer, partner, trustee,
employee, fiduciary, or agent of any other foreign or domestic corporation or of
any partnership, joint venture, trust, other enterprise, or employee benefit
plan against any liability asserted against or incurred by him or her in any
such capacity or arising out of his or her status as such, whether or not the
corporation would have the power to indemnify him or her against such liability
under the provisions of this Article.  Any such insurance may be procured from
any insurance company designated by the board of directors of the corporation,
whether such insurance company is formed under the laws of this state or any
other jurisdiction of the United States or elsewhere, including any insurance
company in which the corporation has equity or any other interest, through stock
ownership or otherwise.

     8.  Notice of Indemnification.  Any indemnification of or advance of
         -------------------------
expenses to a director in accordance with this Article, if arising out of a
proceeding by or on behalf of the corporation, shall be reported in writing to
the shareholders with or before the notice of the next shareholders' meeting.

     9.  Indemnification of Officers, Employees and Agents of the Corporation.
         --------------------------------------------------------------------
The board of directors shall indemnify and advance expenses to an officer,
employee or agent of the corporation who is not a director of the corporation to
the same or greater extent as to a director as provided for in these Articles of
Incorporation, the Bylaws, by resolution of the shareholders or directors, or by
contract, in a manner consistent with the Colorado Corporation Code.

     10.  Indemnification of Heirs, Executors and Administrators.  The
          ------------------------------------------------------
indemnification provided by this Article, shall continue as to a person who has
ceased to be a director, officer, employee or agent, and shall inure to the
benefit of the heirs, executors and administrators of such a person.

     11.  Limitation of Liability.  No director shall be personally liable for
          -----------------------
any injury to person or property arising out of a tort committed by an employee
unless such director was personally involved in the situation giving rise to the
litigation or unless such director committed a criminal offense.  No director
shall be personally liable to the corporation or to its shareholders for
monetary damages for breach of fiduciary duty as a director, excluding (i) any
breach of the director's duty of loyalty to the corporation or to its
shareholders; (ii) acts or omissions not in good faith or which involve
intentional misconduct or a knowing violation of law; (iii) acts in

                                       8


violation of Section 114, Article V of the Colorado Corporate Code; or (iv) any
transaction from which the director derived an improper personal benefit.

                                  ARTICLE VIII
                                  ------------
                                   AMENDMENTS
                                   ----------

     The corporation reserves the right to amend its Articles of Incorporation
from time to time in accordance with the Colorado Corporation Code.

                                   ARTICLE IX
                                   ----------
                        ADOPTION AND AMENDMENT OF BYLAWS
                        --------------------------------

     The initial Bylaws of the corporation shall be adopted by its board of
directors.  The power to alter or amend or repeal the Bylaws or adopt new Bylaws
shall be vested in the board of directors; provided, however, that the
shareholders, upon approval of two-thirds in interest of the outstanding shares
of the corporation entitled to vote at a meeting duly called for that purpose
may alter, amend or repeal and create new Bylaws even though the Bylaws may also
be amended or repealed by the board of directors.

     The Bylaws may contain any provisions for the regulation and management of
the affairs of the corporation not inconsistent with law or these Articles of
Incorporation.

                                   ARTICLE X
                                   ---------
                     REGISTERED OFFICE AND REGISTERED AGENT
                     --------------------------------------

     The address of the initial registered office of the corporation is 707
Seventeenth Street, Suite 2400, Denver, Colorado, and the name of the initial
registered agent at such address is Henry F. Schlueter.  Either the registered
office or the registered agent may be changed in the manner provided by law.

                                   ARTICLE XI
                                   ----------
                           INITIAL BOARD OF DIRECTORS
                           --------------------------

     The number of directors of the corporation shall be fixed by the Bylaws of
the corporation.  So long as the number of directors shall be less than three,
no shares of this corporation may be issued and held of record by more
shareholders than there are directors.  The name and address of the persons who
shall serve as the initial directors until the first annual meeting of
shareholders and until their successors have been elected and shall qualify are
as follows:

NAME                              ADDRESS

Steven J. Bieniewicz              C/O Kutak Rock & Campbell
                                  707 Seventeenth Street, Suite 2400
                                  Denver, Colorado 80202

Martin J. Cuerdon                 C/O Kutak Rock & Campbell

                                       9


                                  707 Seventeenth Street, Suite 2400
                                  Denver, Colorado 80202

Eugene R. Scott                   C/O Kutak Rock & Campbell
                                  707 Seventeenth Street, Suite 2400
                                  Denver, Colorado 80202


                                  ARTICLE XII
                                  -----------
                                  INCORPORATOR
                                  ------------

     The name and address of the incorporator is as follows:

NAME                              ADDRESS

Henry F. Schlueter                Kutak Rock & Campbell
                                  707 Seventeenth Street, Suite 2400
                                  Denver, Colorado 80202

     IN WITNESS WHEREOF, the above-named incorporator has signed these Articles
of Incorporation on November 25, 1991.

                               -----------------------------------------------
                                               Henry F. Schlueter


STATE OF COLORADO   )
   CITY AND         )      ss.
COUNTY OF DENVER    )

     I, the undersigned, a Notary Public, hereby certify that on November 25,
1991, the above-named incorporator personally appeared before me, and being by
me first duly sworn declared that he is the person who signed the foregoing
document as incorporator and that the statements therein contained are true.

     WITNESS my hand and official seal.

                                            ----------------------------------
                                            Notary Public
                                            Address:  707 17th St.  #2400
                                                      -------------------
                                            City and State:  Denver, CA  80202
                                                             -----------------

My Commission expires:  9/21/92
                        -------

(NOTARIAL SEAL)

                                       10