EXHIBIT 4.18

                           AMENDED AND RESTATED BYLAWS
                                       OF
                          EG&G TECHNICAL SERVICES, INC.

                             A Delaware Corporation
                 (Amended and Restated As of September 9, 2004)

                 (FORMERLY KNOWN AS ETS ACQUISITION CORPORATION)

                                    ARTICLE I

                                     OFFICES

      Section 1. The registered office of EG&G Technical Services, Inc. (the
"Corporation") shall be in the City of Wilmington, County of New Castle, State
of Delaware.

      Section 2. The Corporation may also have offices at such other places both
within and without the State of Delaware as the Board of Directors may from time
to time determine or the business of the Corporation may require.

                                   ARTICLE II

                            MEETINGS OF STOCKHOLDERS

      Section 1. Meetings of stockholders shall be held at any place within or
outside the State of Delaware designated by the Board of Directors. In the
absence of any such designation, stockholders' meetings shall be held at the
principal executive office of the Corporation.

      Section 2. The annual meeting of stockholders shall be held each year on a
date and a time designated by the Board of Directors. At each annual meeting
directors shall be elected and any other proper business may be transacted.

      Section 3. A majority of the stock issued and outstanding and entitled to
vote at any meeting of stockholders, the holders of which are present in person
or represented by proxy, shall constitute a quorum for the transaction of
business except as otherwise provided by law, by the Certificate of
Incorporation, or by these Bylaws. A quorum, once established, shall not be
broken by the withdrawal of enough votes to leave less than a quorum and the
votes present may continue to transact business until adjournment. If, however,
such quorum shall not be present or represented at any meeting of the
stockholders, a majority of the voting stock represented in person or by proxy
may adjourn the meeting from time to time, without notice other than
announcement at the



meeting, until a quorum shall be present or represented. At such adjourned
meeting at which a quorum shall be present or represented, any business may be
transacted which might have been transacted at the meeting as originally
notified. If the adjournment is for more than thirty days, or if after the
adjournment a new record date is fixed for the adjourned meeting, a notice of
the adjourned meeting shall be given to each stockholder of record entitled to
vote thereat.

      Section 4. When a quorum is present at any meeting, the vote of the
holders of a majority of the stock having voting power present in person or
represented by proxy shall decide any question brought before such meeting,
unless the question is one upon which by express provision of the statutes, or
the Certificate of Incorporation, or these Bylaws, a different vote is required
in which case such express provision shall govern and control the decision of
such question.

      Section 5. At each meeting of the stockholders, each stockholder having
the right to vote may vote in person or may authorize another person or persons
to act for him by proxy appointed by an instrument in writing subscribed by such
stockholder and bearing a date not more than three years prior to said meeting,
unless said instrument provides for a longer period. All proxies must be filed
with the Secretary of the Corporation at the beginning of each meeting in order
to be counted in any vote at the meeting. Each stockholder shall have one vote
for each share of stock having voting power, registered in his name on the books
of the Corporation on the record date set by the Board of Directors as provided
in Article V, Section 6 hereof. All elections shall be had and all questions
decided by a plurality vote.

      Section 6. Special meetings of the stockholders, for any purpose, or
purposes, unless otherwise prescribed by statute or by the Certificate of
Incorporation, may be called by the President and shall be called by the
President or the Secretary at the request in writing of a majority of the Board
of Directors, or at the request in writing of stockholders owning a majority in
amount of the entire capital stock of the Corporation, issued and outstanding,
and entitled to vote. Such request shall state the purpose or purposes of the
proposed meeting. Business transacted at any special meeting of stockholders
shall be limited to the purpose stated in the notice.

      Section 7. Whenever stockholders are required or permitted to take any
action at a meeting, a written notice of the meeting shall be given which notice
shall state the place, date and hour of the meeting, and, in the case of a
special meeting, the purpose or purposes for which the meeting is called. The
written notice of any meeting shall be given to each stockholder entitled to
vote at such meeting not less than ten nor more than sixty days before the date
of the meeting. If mailed, notice is given when deposited in the United State
mail, postage prepaid, directed to the stockholder at his address as it appears
on the records of the Corporation.

      Section 8. The officer who has charge of the stock ledger of the
Corporation shall prepare and make, at least ten days before every meeting of
stockholders, a complete list of the stockholders entitled to vote at the
meeting, arranged in alphabetical order, and showing the address of each
stockholder and the number of shares registered in the name of each stockholder.
Such list shall be open to the examination of any stockholder, for any purpose
germane to the meeting, during ordinary business hours, for a period of a least
ten days prior to the meeting, either at a place within the city where the
meeting is to be held, which place shall be specified in the notice of the
meeting, or, if not so specified, at the place where the meeting is to be held.
The list shall also be produced and kept at the time and place of the



meeting during the whole time thereof, and may be inspected by any stockholder
who is present.

      Section 9. Unless otherwise provided in the Certificate of Incorporation,
any action required to be taken at any annual or special meeting of stockholders
of the Corporation, or any action which may be taken at any annual or special
meeting of such stockholders, may be taken without a meeting, without prior
notice and without a vote, if a consent in writing, setting forth the action so
taken, shall be signed by the holders of outstanding stock having not less than
the minimum number of votes that would be necessary to authorize or take such
action at a meeting at which all shares entitled to vote thereon were present
and voted. Prompt notice of the taking of the corporate action without a meeting
by less than unanimous written consent shall be given to those stockholders who
have not consented in writing.

                                   ARTICLE III

                                    DIRECTORS

      Section 1. The authorized number of directors shall be determined from
time to time by resolution of the Board of Directors, provided that the Board of
Directors shall consist of at least one member. The directors need not be
stockholders. The directors shall be elected at the annual meeting of the
stockholders, except as provided in Section 2 of this Article, and each director
elected shall hold office until his successor is elected and qualified;
provided, however, that unless otherwise restricted by the Certificate of
Incorporation or by law, any director or the entire Board of Directors may be
removed, either with or without cause, from the Board of Directors at any
meeting of stockholders by a majority of the stock represented and entitled to
vote thereat.

      Section 2. Vacancies on the Board of Directors by reason of death,
resignation, retirement, disqualification, removal from office, or otherwise,
and newly created directorships resulting from any increase in the authorized
number of directors may be filled by a majority of the directors then in office,
although less than a quorum, or by a sole remaining director. The directors then
in office, although less than a quorum, or by a sole remaining director. The
directors so chosen shall hold office until the next annual election of
directors and until their successors are duly elected and shall qualify, unless
sooner replaced by a vote of the shareholders. If there are no directors in
office, then an election of directors may be held in the manner provided by
statute. If, at the time of filling any vacancy or any newly created
directorship, the directors then in office shall constitute less than a majority
of the whole Board (as constituted immediately prior to any such increase), the
Court of Chancery may, upon application of any stockholder or stockholders
holding at least ten percent of the total number of the shares at the time
outstanding having the right to vote for such directors, summarily order an
election to be held to fill any such vacancies or newly created directorships,
or to replace the directors chosen by the directors then in office.

      Section 3. The property and business of the Corporation shall be managed
by or under the direction of its Board of Directors. In addition to the powers
and authorities by these Bylaws expressly conferred upon them, the Board my
exercise all such powers of the



Corporation and do all such lawful acts and things as are not by statute or by
the Certificate of Incorporation or by these Bylaws directed or required to be
exercised or done by the stockholders.

      Section 4. The directors may hold their meetings and have one or more
offices, and keep the books of the Corporation outside of the State of Delaware.

      Section 5. Regular meetings of the Board of Directors may be held without
notice at such time and place as shall from time to time be determined by the
Board.

      Section 6. Special meetings of the Board of Directors may be called by the
Chairman of the Board or the President on forty-eight hours' notice to each
director, either personally or by mail or by telegram; special meetings shall be
called by the President or the Secretary in like manner and on like notice on
the written request of two directors.

      Section 7. At all meetings of the Board of Directors a majority of the
authorized number of directors shall be necessary and sufficient to constitute a
quorum for the transaction of business, and the vote of a majority of the
directors present at any meeting at which there is a quorum, shall be the act of
the Board of Directors, except as may be otherwise specifically provided by
statute, by the Certificate of Incorporation or by these Bylaws. If a quorum
shall not be present at any meeting of the Board of Directors, the directors
present thereat may adjourn the meeting from time to time, without notice other
than announcement at the meeting, until a quorum shall be present. If only one
director is authorized, such sole director shall constitute a quorum. At any
meeting, a director shall have the right to be accompanied by counsel provided
that such counsel shall agree to any confidentiality restrictions reasonably
imposed by the Corporation.

      Section 8. Unless otherwise restricted by the Certificate of Incorporation
or these Bylaws, any action required or permitted to be taken at any meeting of
the Board of Directors or of any committee thereof may be taken without a
meeting, if all members of the Board or committee, as the case may be, consent
thereto in writing, and the writing or writings are filed with the minutes of
proceedings of the Board or committee.

      Section 9. Unless otherwise restricted by the Certificate of Incorporation
or these Bylaws, members of the Board of Directors, or any committee designated
by the Board of Directors, may participate in a meeting of the Board of
Directors, or any committee, by means of conference telephone or similar
communications equipment by means of which all persons participating in the
meeting can hear each other, and such participation in a meeting shall
constitute presence in person at such meeting.

      Section 10. The Board of Directors may, by resolution passed by a majority
of the whole Board, designate one or more committees, each such committee to
consist of one or more of the directors of the Corporation. The Board may
designate one or more directors as alternate members of any committee, who may
replace any absent or disqualified member at any meeting of the committee. In
the absence or disqualification of a member of a committee, the member or
members thereof present at any meeting and not disqualified from voting, whether
or not he or they constitute a quorum, may unanimously appoint another member of
the Board of Directors to act at the meeting in the place of any such



absent or disqualified member. Any such committee, to the extent provided in the
resolution of the Board of Directors, shall have and may exercise all the powers
and authority of the Board of Directors in the management of the business and
affairs of the Corporation, and may authorize the seal of the Corporation to be
affixed to all papers which may require it; but no such committee shall have the
power or authority in reference to amending the Certificate of Incorporation,
adopting an agreement of merger or consolidation, recommending to the
stockholders the sale, lease or exchange of all or substantially all of the
Corporation's property and assets, recommending to the stockholders a
dissolution of the Corporation or a revocation of a dissolution, or amending the
Bylaws of the Corporation; and, unless the resolution or the Certificate of
Incorporation expressly so provide, no such committee shall have the power or
authority to declare a dividend or to authorize the issuance of stock.

      Section 11. Each committee shall keep regular minutes of its meetings and
report the same to the Board of Directors when required.

      Section 12. Unless otherwise restricted by the Certificate of
Incorporation or these Bylaws, the Board of Directors shall have the authority
to fix the compensation of directors. The directors may be paid their expenses,
if any, of attendance at each meeting of the Board of Directors and may be paid
a fixed sum for attendance at each meeting of the Board of Directors or a stated
salary as director. No such payment shall preclude any director from serving the
Corporation in any other capacity and receiving compensation therefor. Members
of special or standing committees may be allowed like compensation for attending
committee meetings.

      Section 13. The Corporation shall indemnify every person who is or was a
party or is or was threatened to be made a party to any action, suit, or
proceeding, whether civil, criminal, administrative or investigative, by reason
of the fact that he is or was a director or officer of the Corporation or, while
a director or officer or employee of the Corporation, is or was serving at the
request of the Corporation as a director, officer, employee, agent or trustee of
another corporation, partnership, joint venture, trust, employee benefit plan or
other enterprise, against expenses (including counsel fees), judgments, fines
and amounts paid in settlement actually and reasonably incurred by him in
connection with such action, suit or proceeding, to the full extent permitted by
applicable law.

                                   ARTICLE IV

                                    OFFICERS

      Section 1. The officers of this corporation shall be chosen by the Board
of Directors and shall include a President, a Secretary, and a Treasurer. The
Corporation may also have, at the discretion of the Board of Directors, such
other officers as are desired, including a Chairman of the Board, one or more
Vice Presidents, one or more Assistant Secretaries and Assistant Treasurers, and
such other officers as may be appointed in accordance with the provisions of
Section 3 hereof. In the event there are two or more Vice Presidents, then one
or more may be designated as Executive Vice President, Senior Vice President, or
other similar or dissimilar title. At the time of the election of officers, the
directors may by



resolution determine the order of their rank. Any number of offices may be held
by the same person unless the Certificate of Incorporation or these Bylaws
otherwise provide.

      Section 2. The Board of Directors, at its first meeting after each annual
meeting of stockholders, shall choose the officers of the Corporation.

      Section 3. The Board of Directors may appoint such other officers and
agents as it shall deem necessary who shall hold their offices for such terms
and shall exercise such powers and perform such duties as shall be determined
from time to time by the Board.

      Section 4. The salaries of all officers and agents of the Corporation
shall be fixed by the Board of Directors.

      Section 5. The officers of the Corporation shall hold office until their
successors are chosen and qualify in their stead. Any officer elected or
appointed by the Board of Directors may be renewed at any time by the
affirmative vote of a majority of the Board of Directors. If the office of any
officer or officers becomes vacant for any reason, the vacancy shall be filled
by the Board of Directors.

      Section 6. Chairman of the Board. The Chairman of the Board, if such an
officer be elected, shall, if present, preside at all meetings of the Board of
Directors and exercise and perform such other powers and duties as may be from
time to time assigned to him by the Board of Directors or prescribed by these
Bylaws. If there is no President, the Chairman of the Board shall in addition be
the Chief Executive Officer of the Corporation and shall have the powers and
duties prescribed in Section 7 of this Article IV.

      Section 7. President. Subject to such supervisory powers, if any, as may
be given by the Board of Directors to the Chairman of the Board, if there be
such an officer, the President shall be the Chief Executive Officer of the
Corporation and shall, subject to the control of the Board of Directors, have
general supervision, direction and control of the business and officers of the
Corporation. He shall preside at all meetings of the stockholders and, in the
absence of the Chairman of the Board, or if there be none, at all meetings of
the Board of Directors. He shall be an ex-officio member of all committees and
shall have the general powers and duties of management usually vested in the
office of President and Chief Executive Officer of corporations, and shall have
such other powers and duties as may be prescribed by the Board of Directors or
these Bylaws.

      Section 8. Vice Presidents. In the absence or disability of the President
the Vice Presidents in order of their rank as fixed by the Board of Directors,
or if not ranked, the Vice President designated by the Board of Directors, shall
perform all the duties of the President, and when so acting shall have all the
powers of and be subject to all the restrictions upon the President. The Vice
President shall have such other duties as from time to time may be prescribed
for them, respectively, by the Board of Directors.

      Section 9. Secretary. The Secretary shall attend all sessions of the Board
of Directors and all meetings of the stockholders and record all votes and the
minutes of all proceedings in a book to be kept for that purpose; and shall
perform like duties for the standing committees when required by the Board of
Directors. He shall give, or cause to be given,



notice of all meetings of the stockholders and of the Board of Directors, and
shall perform such other duties as may be prescribed by the Board of Directors
or these Bylaws.

      He shall keep in safe custody the seal of the Corporation, and when
authorized by the Board, affix the same to any instrument requiring it, and when
so affixed it shall be attested by his signature or by the signature of an
Assistant Secretary. The Board of Directors may give general authority to any
other officer to affix the seal of the Corporation and to attest the affixing by
his signature.

      Section 10. Assistant Secretary. The Assistant Secretary, or if there be
more than one, the Assistant Secretaries in the order determined by the Board of
Directors, or if there be no such determination, the Assistant Secretary
designated by the Board of Directors, shall, in the absence or disability of the
Secretary, perform the duties and exercise the powers of the Secretary and shall
perform such others duties and have such other powers as the Board of Directors
may from time to time prescribe.

      Section 11. Treasurer. The Treasurer shall have the custody of the
corporate funds and securities and shall keep full and accurate accounts of
receipts and disbursements in books belonging to the Corporation and shall
deposit all moneys, and other valuable effects in the name and to the credit of
the Corporation, in such depositories as may be designated by the Board of
Directors. He shall disburse the funds of the Corporation as may be ordered by
the Board of Directors, taking proper vouchers for such disbursements, and shall
render to the Board of Directors, at its regular meetings, or when the Board of
Directors so requires, an account of all his transactions as Treasurer and of
the financial condition of the Corporation. If required by the Board of
Directors, he shall give the Corporation a bond, in such sum and with such
surety or sureties as shall be satisfactory to the Board of Directors, for the
faithful performance of the duties of his office and for the restoration to the
Corporation, in case of his death, resignation, retirement or removal from
office, of all books, papers, vouchers, money and other property of whatever
kind in his possession or under his control belonging to the Corporation.

      Section 12. Assistant Treasurer. The Assistant Treasurer, or if there
shall be more than one, the Assistant Treasurers in the order determined by the
Board of Directors, or if there be no such determination, the Assistant
Treasurer designated by the Board of Directors, shall, in the absence or
disability of the Treasurer, perform the duties and exercise the power of the
Treasurer and shall perform such other duties and have such other powers as the
Board of Directors may from time to time prescribe.



                                    ARTICLE V

                              CERTIFICATES OF STOCK

      Section 1. Every holder of stock of the Corporation shall be entitled to
have a certificate signed by, or in the name of the Corporation by, the Chairman
or Vice Chairman of the Board of Directors, or the President or a Vice
President, and by the Secretary or an Assistant Secretary, or the Treasurer or
an Assistant Treasurer of the Corporation, certifying the number of shares
represented by the certificate owned by such stockholder in the Corporation.

      Section 2. Any or all of the signatures on the certificate may be
facsimile. In case any officer, transfer agent, or register who has signed or
whose facsimile signature has been placed upon a certificate shall have ceased
to be such officer, transfer agent, or registrar before such certificate is
issued, it may be issued by the Corporation with the same effect as if he were
such officer, transfer agent, or registrar at the date of issue.

      Section 3. If the Corporation shall be authorized to issue more than one
class of stock or more than one series of any class, the powers, designations,
preferences and relative, participating, optional or other special rights of
each class of stock or series thereof and the qualification, limitations or
restrictions of such preferences and/or rights shall be set forth in full or
summarized on the face or back of the certificate which the Corporation shall
issue to represent such class or series of stock, provided that, except as
otherwise provided in Section 202 of the General Corporation Law of Delaware, in
lieu of the foregoing requirements, there may be set forth on the face or back
of the certificate which the Corporation shall issue to represent such class or
series of stock, a statement that the Corporation will furnish without charge to
each stockholder who so requests the powers, designations, preferences and
relative, participating, optional or other special rights of each class of stock
or series thereof and the qualifications, limitations or restrictions of such
preferences and/or rights.

      Section 4. The Board of Directors may direct a new certificate or
certificates to be issued in place of any certificate or certificates
theretofore issued by the Corporation alleged to have been lost, stolen or
destroyed, upon the making of an affidavit of that fact by the person claiming
the certificate of stock to be lost, stolen or destroyed. When authorizing such
issue of a new certificate or certificates, the Board of Directors may, in its
discretion and as a condition precedent to the issuance thereof, require the
owner of such lost, stolen or destroyed certificate or certificates, or his
legal representative, to advertise the same in such manner as it shall require
and/or to give the Corporation a bond in such sum as it may direct as indemnity
against any claim that may be made against the Corporation with respect to the
certificate alleged to have been lost, stolen or destroyed.

      Section 5. Upon surrender to the Corporation, or the transfer agent of the
Corporation, of a certificate for shares duly endorsed or accompanied by proper
evidence of succession, assignation or authority to transfer, the Corporation
shall issue a new certificate to the person entitled thereto, cancel the old
certificate and record the transaction upon its book.

      Section 6. In order that the Corporation may determine the stockholders
entitled to notice of or to vote at any meeting of the stockholders, or any
adjournment thereof, or to express consent to corporate action in writing
without a meeting, or entitled to receive payment of any dividend or other
distribution or allotment of any rights, or entitled to exercise any rights in
respect of any change, conversion or exchange of stock or for the



purpose of any other lawful action, the Board of Directors may fix a record date
which shall not be more than sixty nor less than ten days before the date of
such meeting, nor more than sixty days prior to any other action. A
determination of stockholder of record entitled to notice of or to vote at a
meeting of stockholder shall apply to any adjournment of the meeting; provided,
however, that the Board of Directors my fix a new record date for the adjourned
meeting.

      Section 7. The Corporation shall be entitled to treat the holder of record
of any share or shares of stock as the holder in fact thereof and accordingly
shall not be bound to recognize any equitable or other claim or interest in such
share on the part of any other person, whether or not it shall have express or
other notice thereof, save as expressly provided by the laws of the State of
Delaware.

                                   ARTICLE VI

                               GENERAL PROVISIONS

      Section 1. Dividends upon the capital stock of the Corporation, subject to
the provisions of the Certificate of Incorporation, if any, may be declared by
the Board of Directors at any regular or special meeting, pursuant to law.
Dividends may be paid in cash, in property, or in shares of the capital stock,
subject to the provisions of the Certificate of Incorporation.

      Section 2. Before payment of any dividend there may be set aside out of
any funds of the Corporation available for dividends such sum or sums as the
directors from time to time, in their absolute discretion, think proper as a
reserve fund to meet contingencies, or for equalizing dividends, or for
repairing or maintaining any property of the Corporation, or for such other
purpose as the directors shall think conducive to the interests of the
Corporation, and the directors may abolish any such reserve.

      Section 3. All checks or demands for money and notes of the Corporation
shall be signed by such officer or officers as the Board of Directors may from
time to time designate.

      Section 4. The fiscal year of the corporation shall be fixed by resolution
of the Board of Directors.

      Section 5. The corporate seal shall inscribed thereon the name of the
Corporation, the year of its organization and the words "Corporate Seal,
Delaware". Said seal may be used by causing it or a facsimile thereof to be
impressed or affixed or reproduced or otherwise.

      Section 6. Whenever, under the provisions of the statutes or of the
Certificate of Incorporation or of these Bylaws, notice is required to be given
to any director or stockholder, it shall not be construed to mean personal
notice, but such notice may be given in writing, by mail, addressed to such
director or stockholder, at his address as it appears on the records of the
Corporation, with postage thereon prepaid, and such notice shall be deemed to be
given at the time when the same shall be deposited in the United States mail.
Notice to directors may also be given by telegram.



      Section 7. Whenever any notice is required to be given under the
provisions of the statutes or of the Certificate of Incorporation or of these
Bylaws, a waiver thereof in writing, signed by the person or persons entitled to
said notice, whether before or after the time stated therein, shall be deemed
equivalent thereto.

      Section 8. The Board of Directors shall present at each annual meeting,
and at any special meeting of the stockholders when called for by vote of the
stockholders, a full and clear statement of the business and condition of the
Corporation.

                                   ARTICLE VII

                                   AMENDMENTS

      Section 1. These Bylaws may be altered, amended or repealed or new Bylaws
may be adopted by the stockholders or by the Board of Directors at any regular
meeting of the stockholders or of the Board of Directors or at any special
meeting of the stockholders or of the Board of Directors if notice of such
alteration, amendment, repeal or adoption of new Bylaws be contained in the
notice of such special meeting. If the power to adopt, amend or repeal Bylaws is
conferred upon the Board of Directors by the Certificate of Incorporation, it
shall not divest or limit the power of the stockholders to adopt, amend or
repeal Bylaws.