EXHIBIT 4.1j



<PAGE>

                                                  May 31, 2001


Mr. Emanuel N. Logothetis, Chairman
Joule, Inc.
1245 Route 1 South
Edison, New Jersey 08837

          Re:  Fleet  National  Bank, as successor by merger to Summit Bank -to-
               Joule, Inc.

Dear Mr. Logothetis:

     Reference is hereby made to a certain Loan and Security  Agreement dated as
of February  20, 1991,  as  previously  amended and  modified  from time to time
(hereinafter  referred  to as the "Loan  Agreement"),  executed  by and  between
Joule, Inc., a Delaware corporation  (hereinafter referred to as the "Borrower")
and Fleet  National Bank, as successor by merger to Summit Bank, as successor in
interest  to United  Jersey  Bank  (hereinafter  referred  to as the  "Lender"),
pursuant  to which the  Lender  has made  available  to the  Borrower  a secured
revolving  credit  loan  in the  amended  aggregate  principal  amount  of up to
$9,000,000.00  (hereinafter  referred to as the "Loan Facility").  Defined terms
used but not  expressly  defined  herein shall have the same  meanings when used
herein as set forth in the Loan Agreement.

     The Borrower has requested  that the Lender,  and the Lender has agreed to,
amend and modify the terms,  conditions and provisions of the Loan Agreement and
the other Loan  Documents  for the purposes  more fully set forth and  described
hereinbelow. Therefore, the parties hereby covenant and agree as follows:

     1. As of the date hereof,  the existing  Article I, Section  1.1(ll) of the
Loan  Agreement  is hereby  deleted and the  following  new  Article I,  Section
1.1(ll) is hereby inserted in its place and stead:

          "(ll)"Termination Date" shall mean May 31, 2002."

     2. In furtherance  of the foregoing,  any and all references to a "maturity
date" or to the date on which the Loan Facility matures and/or expires in any of
the Loan  Documents  is hereby  amended  and  modified  to delete  the  existing
maturity  and/or  expiration  date of "May 31,  2001" and insert a new  maturity
and/or expiration date of "May 31, 2002" in their place and stead.


<PAGE>

Mr. Emanuel N. Logothetis, Chairman
Joule, Inc.
May 31, 2001
Page 2


     3. As of the date hereof,  the existing  Base Rate interest rate option set
forth in Article II, Section  2.4(1) of the Loan  Agreement  shall be deleted in
its  entirety  and the  following  new Base Rate  interest  rate option shall be
inserted in its place and stead:

     "(1) Base Rate:A fluctuating interest rate per annum equal to the Base Rate
          of the Lender for such day, in effect from time to time (such interest
          rate to change  immediately  upon any change in the Base  Rate)  minus
          fifty basis points (0.5%)."

     4. The Borrower and the Corporate  Guarantors hereby confirm,  reaffirm and
acknowledge the representations and warranties  contained in the Loan Agreement,
the  Corporate   Guaranty   Agreements  and  any  and  all   amendments   and/or
modifications   thereto.  The  Borrower  and  the  Corporate  Guarantors  hereby
represent and warrant to the Lender that all  representations  and warranties of
the Borrower and the Corporate Guarantors,  respectively,  contained in the Loan
Agreement, the Corporate Guaranty Agreements and all of the other Loan Documents
continue  to be true,  accurate  and correct as of the date hereof as if made on
and as of the date hereof.  All Obligations of the Borrower and/or the Corporate
Guarantors to the Lender are due without any offset,  defenses or  counterclaims
whatsoever.

     5. Except as expressly  amended and/or  modified by this letter  amendment,
all terms,  conditions  and  provisions  of the Loan  Agreement,  the  Corporate
Guaranty  Agreements and the other Loan Documents shall remain  unchanged and in
full force and effect.  The parties hereto expressly confirm and reaffirm all of
their  respective  liabilities,   obligations  and  responsibilities  under  and
pursuant to the Loan Agreement,  the Corporate Guaranty Agreements and the other
Loan Documents, as amended and modified by this letter amendment.

     6. The Borrower and the Corporate Guarantors do hereby:

          (i) ratify,  confirm and  acknowledge  that,  as amended and  modified
     hereby, the Loan Documents continue to be valid,  binding and in full force
     and effect;

          (ii) covenant and agree to perform all of their respective obligations
     contained in the Loan Agreement,  the Corporate Guaranty Agreements and the
     other Loan Documents, as amended and modified hereby;

          (iii)represent   and  warrant   that,   after  giving  effect  to  the
     transactions  contemplated  by this letter  amendment,  no Event of Default
     exists or will exist upon the delivery of notice, passage of time, or both;

          (iv)  acknowledge  and agree  that  nothing  contained  herein  and no
     actions  taken  pursuant to the terms hereof are  intended to  constitute a
     novation of the Loan  Facility,  or any waiver of the Loan  Agreement,  the
     Corporate Guaranty  Agreements and/or any of the


<PAGE>

Mr. Emanuel N. Logothetis, Chairman
Joule, Inc.
May 31, 2001
Page 3


     other Loan  Documents,  and do not  constitute  a release,  termination  or
     waiver of any of the rights and/or remedies granted to the Lender under the
     Loan Documents;

          (v)  acknowledge and agree that the failure by the Borrower and/or any
     of the  Corporate  Guarantors  to  comply  with  or  perform  any of  their
     respective  covenants,  agreements or  obligations  contained  herein shall
     constitute an Event of Default under the Loan Agreement;

          (vi) represent and warrant that none of the by-laws,  certificates  of
     incorporation or other corporate governing documents of the Borrower and/or
     any  of  the  Corporate  Guarantors  have  been  amended,  modified  and/or
     supplemented in any way since the date such documents were delivered to the
     Lender; and

          (vii)represent and warrant that each of the Borrower and the Corporate
     Guarantors has taken all necessary  corporate action required by law and by
     its respective  corporate  governing  documents to execute and deliver this
     letter amendment and that such execution and delivery constitutes the legal
     and validly binding action of such corporation.

     7. Nothing  contained in this letter amendment  constitutes an agreement or
obligation by the Lender to grant any further amendments and/or modifications to
the Loan Agreement and/or any of the other Loan Documents and nothing  contained
herein shall  constitute a waiver or  modification of any of the Lender's rights
and remedies or of any of the terms, conditions, warranties,  representations or
covenants  contained in the Loan  Agreement  and any and all  amendments  and/or
modifications  thereto,  and the Lender  hereby  reserves  all of its rights and
remedies  pursuant  to the  Loan  Agreement  and any and all  amendments  and/or
modifications thereto and applicable law.

     8. This letter  amendment  may be  executed in any number of  counterparts,
each of which, when taken together, shall be deemed one and the same instrument.


<PAGE>

Mr. Emanuel N. Logothetis, Chairman
Joule, Inc.
May 31, 2001
Page 4


     Kindly indicate the agreement of the Borrower and Corporate Guarantors with
the terms and conditions of this letter amendment by countersigning in the space
provided below,  and returning a countersigned  copy of this letter amendment to
the  undersigned.  This  letter  amendment  shall  become null and void unless a
countersigned copy is returned within fourteen (14) days from the date hereof.

                                           Very truly yours,

                                           FLEET NATIONAL BANK, as successor by
                                           merger to Summit Bank


                                           By:___________________________
                                              Cynthia Colucci
                                              Vice President

--------------------------------------------------------------------------------

ACCEPTED AND AGREED AS OF THIS _______ DAY OF ___________, 2001:


BORROWER:

JOULE, INC., a Delaware corporation


By:_____________________________
      Emanuel N. Logothetis
      Chairman of the Board


CORPORATE GUARANTORS:

JOULE MAINTENANCE CORPORATION,
a New Jersey corporation


By:________________________________
      Emanuel N. Logothetis
      Chairman of the Board


<PAGE>

Mr. Emanuel N. Logothetis, Chairman
Joule, Inc.
May 31, 2001
Page 5


JOULE TECHNICAL SERVICES, INC. ,
a New Jersey corporation


By:________________________________
      Emanuel N. Logothetis
      Chairman of the Board


JOULE TECHNICAL STAFFING, INC.,
a New Jersey corporation


By:________________________________
      Emanuel N. Logothetis
      Chairman of the Board