**Exhibit10.(c)(xxviii)**

**THIRDAMENDMENT TO LEASE**

This THIRDAMENDMENT TO LEASE (this “**Third****Amendment**”) is made as of the 1st day of January, 2007 (the “**Effective Date**”) by and between DIRECT INVEST – 829 MIDDLESEX, LLC; DIRECT INVEST – 829 MIDDLESEX 1,LLC; DIRECT INVEST – 829 MIDDLESEX 2, LLC; DIRECT INVEST – 829 MIDDLESEX 3,LLC; DIRECT INVEST – 829 MIDDLESEX 4, LLC; DIRECT INVEST – 829 MIDDLESEX 5,LLC; DIRECT INVEST – 829 MIDDLESEX 6, LLC; DIRECT INVEST – 829 MIDDLESEX 7,LLC; DIRECT INVEST – 829 MIDDLESEX 8, LLC; DIRECT INVEST – 829 MIDDLESEX 9,LLC; DIRECT INVEST – 829 MIDDLESEX 10, LLC; DIRECT INVEST – 829 MIDDLESEX 11,LLC; DIRECT INVEST – 829 MIDDLESEX 12, LLC; DIRECT INVEST – 829 MIDDLESEX 13,LLC; DIRECT INVEST – 829 MIDDLESEX 14, LLC; DIRECT INVEST – 829 MIDDLESEX 15,LLC; DIRECT INVEST – 829 MIDDLESEX 16, LLC; DIRECT INVEST – 829 MIDDLESEX 17,LLC; and DIRECT INVEST – 829 MIDDLESEX 18, LLC as successor in interest toMiddlesex Development Limited Partnership (“**Landlord**”), and AMERICAN SCIENCE AND ENGINEERING, INC., (“**Tenant**”).

R E C I T A L S

A.            The Landlord andTenant entered into that certain Lease dated January 12, 1995, as amended bythat certain First Amendment dated June 11, 1997 and that certain SecondAmendment to Lease dated December 3, 2004 (the “**OriginalLease**”), of certain premises consisting of approximately 166,374rentable square feet of space (the “**Original****Premises**”) within the building located at829 Middlesex Turnpike, Billerica, Massachusetts (the “**Building**”), for a Term that is scheduled toexpire on February 29, 2016, as more particularly described in the OriginalLease.

B.            Landlord and Tenantwish to amend the Original Lease to (i) expand the Premises by the addition ofapproximately 19,826 rentable square feet of space as shown on **Exhibit A** (the “**Expansion Premises**”); and (ii) amend certain other terms ofthe Original Lease.

NOW, THEREFORE,for good and valuable consideration, the receipt and sufficiency of which arehereby mutually acknowledged, Landlord and Tenant agree as follows:

# 1.             ­Recitals;Capitalized Terms.  All of theforegoing recitals are true and correct. Unless otherwise defined herein, allcapitalized terms used in this Third Amendment shall have the meanings ascribedto them in the Original Lease, and all references in the Original Lease to the “Lease”or “this Lease” or “herein” or “hereunder” or similar terms or to any sectionthereof shall mean the Original Lease, or such section thereof, as amended bythis Third Amendment.  The OriginalLease, as amended by this Third Amendment, is hereinafter referred to as the “**Lease**.” 

# 2.             Expansion ofPremises.

## (a)           Landlordhereby leases to Tenant and Tenant hereby leases from Landlord, subject to theterms, covenants, conditions and provisions of the Lease, the Expansion 

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## Premises for aterm commencing on January 1, 2007 (the “**ExpansionPremises Commencement Date**”) and expiring on February 29, 2016,subject to extension pursuant to any options to extend the Term of the Leaseexpressly set forth in the Original Lease. The Expansion Premises are being leased in their present condition, asis, without representation or warranty by Landlord.  Commencing on the Expansion PremisesCommencement Date, the Premises under the Lease shall mean and refer to theOriginal Premises and the Expansion Premises.

# 3.             Fixed Rent.  Commencing on the Expansion PremisesCommencement Date, in addition to the Fixed Rent payable with respect to theOriginal Premises, Tenant shall pay Fixed Rent to Landlord for the ExpansionPremises, at the times and in the manner set forth in the Original Lease, inthe following amounts:

| **Lease Year**                       | ** ** | **Fixed Rent per RSF** | ** ** | **Fixed Rent per   Month** | ** ** | **Fixed Rent per Year** | ** ** |
|-------------------------------------------|------------|---------------------------------------|------------|-------------------------------------------|------------|----------------------------------------|------------|
| ** **                                | ** ** | ** **                            | ** ** | ** **                                | ** ** | ** **                             | ** ** |
| January 1, 2007 –  December 31, 2009 |       | $                                     | 8.75       |                                      | $          | 14,456.46                              |       | $ | 173,477.50 |   |
|                                      |       |                                  |       |                                      |       |                                   |       |
| January 1, 2010 –  December 31, 2012 |       | $                                     | 9.25       |                                      | $          | 15,282.54                              |       | $ | 183,390.50 |   |
|                                      |       |                                  |       |                                      |       |                                   |       |
| January 1, 2013 –  February 29, 2016 |       | $                                     | 9.50       |                                      | $          | 15,695.58                              |       | $ | 188,347.00 |   |

 

# 4.             Tenant’sPercentage.  Commencing on theExpansion Premises Commencement Date, “Tenant’s Percentage” shall be 100% forall purposes under the Lease.

# 5.             Tenant’sImprovement Allowance.

## (a)           Providedthat Tenant is not then in default under the Lease, Landlord agrees to payTenant, within thirty (30) business days after the date of this Third Amendmentfirst set forth above, an improvement allowance of $366,781.00 (“**Improvement Allowance**”) for use inpreparing the Expansion Space for its use and occupancy (the “**Expansion Premises Work**”).  In the event that Landlord shall default inthe foregoing obligation to pay the Improvement Allowance and such defaultshall continue for more than thirty (30) days after written notice from Tenantof such default, Tenant shall have the right to offset such amounts against thenext due payments of Fixed Rent and Additional Rent under the Lease up to thetotal amount of the Improvement Allowance. The Expansion Premises Work shall be subject to, and performed inaccordance with, Section 6.2.5 of the Lease, except that Landlord shall notrequire Tenant to obtain a bond in connection with the Expansion PremisesWork.  Tenant shall deliver to Landlordarchitectural plans showing that the Expansion Premises Work shall consist ofat least ten percent (10%) office space. Tenant shall substantially complete the Expansion Premises Work on or beforeJune 30, 2008.  Upon substantialcompletion of the Expansion Premises Work, Tenant shall deliver to Landlord,(i) copies of final lien waivers for Tenant’s contractors; (ii) a certificateof occupancy for the Expansion Premises, (iii) a certificate signed by the 

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## Tenant’sarchitect certifying that the Expansion Premises Work has been completedsubstantially in accordance with the approved plans, and (iv) delivery ofas-built plans of the Expansion Premises Work. Notwithstanding anything to the contrary contained herein, if the firstmortgagee of the Premises does not consent to an initial payment of theImprovement Allowance, Landlord’s obligation to make such funds available shallbe subject to delivery of the items set forth in clauses (i) through (iv)above, as well as any satisfaction by Tenant of any other requirement of suchmortgagee to the release of the Improvement Allowance.

## (b)           Inaddition to improvements to the Expansion Space, Tenant agrees that it shallinstall exterior doors on or before June 30, 2008 at its sole cost andexpense.  Tenant agrees thatnotwithstanding anything to the contrary contained in the Original LeaseLandlord shall have no obligation to Tenant to perform the foregoing door workor to (i) paint the Building exterior; or (ii) construct or install exteriorsignage, including, without limitation, a new monument sign.

# 6.             Parking andLoading Dock.  Subject to the termsand conditions of the Lease,  Tenantshall have the exclusive right to park in the parking areas of the property andshall also have the exclusive right to use the existing loading docks for theBuilding.

# 7.             Brokerage.   Landlord and Tenant each represent andwarrant to the other that they have not directly or indirectly dealt with anybroker with respect to this Third Amendment except for The Codman Company andThe Staubach Company.  Landlord agreesthat it shall be responsible for payment of brokerage fees pursuant to aseparate agreement.  Each party agrees toexonerate and save harmless and indemnify the other against any claims for acommission by any broker, person or firm (other than The Codman Company and TheStaubach Company) with whom such party has dealt in connection with theexecution and delivery of this Third Amendment or arising out of negotiationsbetween Landlord and Tenant with respect to the Premises.

# 8.             ­Ratification.  Except as expressly modified by this ThirdAmendment, the Lease shall remain in full force and effect, and as furthermodified by this Third Amendment, is expressly ratified and confirmed by theparties hereto.  This Third Amendmentshall be binding upon and inure to the benefit of the parties hereto and theirrespective successors and assigns, subject to the provisions of the Lease regardingassignment and subletting.

# 9.             ­Governing Law;Interpretation and Partial Invalidity. This Third Amendment shall be governed and construed in accordance withthe laws of the Commonwealth of Massachusetts. If any term of this Third Amendment, or the application thereof to anyperson or circumstances, shall to any extent be invalid or unenforceable, theremainder of this Third Amendment, or the application of such term to personsor circumstances other than those as to which it is invalid or unenforceable,shall not be affected thereby, and each term of this Third Amendment shall bevalid and enforceable to the fullest extent permitted by law.  The titles for the paragraphs are forconvenience only and are not to be considered in construing this Third Amendment.  This Third Amendment contains all of theagreements of the parties with respect to the subject matter hereof, andsupersedes all prior dealings between them with respect to such subjectmatter.  No delay or omission on the partof either party to this Third Amendment in requiring performance by the otherparty or exercising any right hereunder shall operate as a 

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# waiver of any provision hereof or any rightshereunder, and no waiver, omission or delay in requiring performance orexercising any right hereunder on any one occasion shall be construed as a barto or waiver of such performance or right on any future occasion.

# 10.           ­Binding Agreement.  This document shall become effective andbinding only upon the execution and delivery of this Third Amendment by bothLandlord and Tenant and the parties obtaining the written consent to this ThirdAmendment from the current first mortgagee of the property.  In the event that the consent of suchmortgagee has not been obtained within thirty (30) business days from the dateof this Third Amendment first set forth above, this Third Amendment shall bedeemed null and void and of no further force or effect.

# 11.           Counterparts andAuthority. This Third Amendment may be executed in multiple counterparts,each of which shall be deemed an original and all of which together shallconstitute one and the same document. Landlord and Tenant each warrant to the other that the person or personsexecuting this Third Amendment on its behalf has or have authority to do so andthat such execution has fully obligated and bound such party to all terms andprovisions of this Third Amendment.

[Remainder of PageIntentionally Blank]

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IN WITNESSWHEREOF, the undersigned executed this Third Amendment as of the date and yearfirst written above.

 
| LANDLORD:                                                              |   |                                                                          |
|------------------------------------------------------------------------|--------|-------------------------------------------------------------------------------|
|                                                                   |   |                                                                          |
| DIRECT INVEST PROPERTY  MANAGEMENT, L.L.C.,                            |
| a Delaware limited  liability company, as authorized agent of Landlord |
|                                                                   |
|                                                                   | By:    | Direct Invest, L.L.C., a Delaware limited liability company, its  Sole Member |
|                                                                   |
|                                                                   | By:    | NPV DI, L.L.C., a Delaware limited liability company, its  Managing Member    |
|                                                                   |
|                                                                   | BY:    |                                                                          | /s/ William F. Randz |   |   |
|                                                                   |   | Name:  William  F. Randz                                            |
|                                                                   |   | Title:    Manager                                         |
|                                                                   |   |                                                                          |
|                                                                   |   |                                                                          |
| TENANT:                                                                |
|                                                                   |
| AMERICAN SCIENCE AND  ENGINEERING, INC.                                |
|                                                                   |   |                                                                          |
|                                                                   | BY:    |                                                                          | /s/ Kenneth Galaznik  CFO |   |   |   |   |
|                                                                   |   | Name:  Kenneth  Galaznik                                            |
|                                                                   |   | Title:    CFO                                             |
|                                                                        |        |                                                                               |  |  |  |  |  |  |  |  |  |  |  |  |

 

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**EXHIBIT A**

**Plan ofExpansion Premises**

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