Exhibit 3.9



                          CERTIFICATE OF INCORPORATION
                          ----------------------------

                                       OF
                                       --

                           NES EAST ACQUISITION CORP.
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                                  ARTICLE ONE
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          The name of the corporation is NES East Acquisition Corp.


                                  ARTICLE TWO
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          The address of the corporation's registered office in the State of
Delaware is 9 East Loockerman Street, in the City of Dover, County of Kent
19901.  The name of its registered agent at such address is National Registered
Agents, Inc.


                                 ARTICLE THREE
                                 -------------


          The nature of the business or the purpose to be conducted or promoted
is to engage in any lawful act or activity for which corporations may be
organized under the General Corporation Law of the State of Delaware.

                                  ARTICLE FOUR
                                  ------------


          The total number of shares of stock which the corporation has
authority to issue is 1,000 shares of Common Stock, with a par value of $.01 per
share.


                                  ARTICLE FIVE
                                  ------------


          The name and mailing address of the sole incorporator are as follows:

               NAME                     MAILING ADDRESS
               ----                     ---------------

               Joan D. Donovan      200 East Randolph Drive
                                    Suite 5700
                                    Chicago, Illinois  60601

 
                                  ARTICLE SIX
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          The corporation is to have perpetual existence.


                                 ARTICLE SEVEN
                                 -------------


          In furtherance and not in limitation of the powers conferred by
statute, the board of directors of the corporation is expressly authorized to
make, alter or repeal the by-laws of the corporation.


                                 ARTICLE EIGHT
                                 -------------


          Meetings of stockholders may be held within or without the State of
Delaware, as the by-laws of the corporation may provide.  The books of the
corporation may be kept outside the State of Delaware at such place or places as
may be designated from time to time by the board of directors or in the by-laws
of the corporation.  Election of directors need not be by written ballot unless
the by-laws of the corporation so provide.


                                  ARTICLE NINE
                                  ------------


          To the fullest extent permitted by the General Corporation Law of the
State of Delaware as the same exists or may hereafter be amended, a director of
this corporation shall not be liable to the corporation or its stockholders for
monetary damages for a breach of fiduciary duty as a director.  Any repeal or
modification of this ARTICLE NINE shall not adversely affect any right or
                     ------------                                        
protection of a director of the corporation existing at the time of such repeal
or modification.
 

                                  ARTICLE TEN
                                  -----------


          The corporation expressly elects not to be governed by Section 203 of
the General Corporation Law of the State of Delaware.

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                                 ARTICLE ELEVEN
                                 --------------


          The corporation reserves the right to amend, alter, change or repeal
any provision contained in this certificate of incorporation in the manner now
or hereafter prescribed herein, by the unanimous written consent of the board of
directors of the corporation and by the laws of the State of Delaware, and all
rights conferred upon stockholders herein are granted subject to this
reservation.

          I, THE UNDERSIGNED, being the sole incorporator hereinbefore named,
for the purpose of forming a corporation pursuant to the General Corporation Law
of the State of Delaware, do make this certificate, hereby declaring and
certifying that this is my act and deed and the facts stated herein are true,
and accordingly have hereunto set my hand on the 3rd day of February, 1998.


                                      /s/ Joan D. Donovan
                                    ------------------------
                                    Joan D. Donovan, Sole Incorporator

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