Biographical Sketches -- Proposal Section E Biographical sketches are limited to two pages each and are

Biographical Sketch

Zuheir Subhi Saleh El-bayyari, Ph.D

Philadelphia University

Faculty of Science

Department of Basic Sciences-Mathematics

P. O. Box 1 Philadelphia University 19392 Jordan

Phone: + 962-2-637 4444 and + (962) – 6- 4799000 ext. 2660

Fax : + 962-2-637 4440

Mobile: + 962-79-5564225

e-mail: z_bayyari@philadelphia.edu.jo

e-mail: zbayyari@rocketmail.com

A. Personal Data:

Full Name Zuheir Subhi Saleh El - Bayyari.

Academic Title Associate Professor.

Date of Birth January 31, 1962.

Place of Birth Amman - Jordan.

Nationality Jordanian.

Passport No. H 889658.

Date of Issue 02 / 02 / 2003.

Date of Expire 01 / 02 / 2008.

Marital Status Single, with one child.

Current address Philadelphia University

Faculty of Science

Department of Basic Sciences

P. O. Box 1

Philadelphia University 19392 JORDAN.

electronic- mail address z_bayyari@philadelphia.edu.jo

zbayyari@rocketmail.com

Telephone (work) + (962) - 2 - 637 4444 and + (962) – 6- 4799000 ext. 2660

Fax + (962) - 2 - 637 4440

Mailing Address Amman Al – Ashrafiyeh

P. O. Box 510852

Amman 11151 JORDAN.

Telephone (home) + (962) -

Telephone (Mobile) + (962) -

Fax + (962) - 6 - 5711317

B. Professional Preparation:

Undergraduate Institution(s):

Yarmouk University (Irbid – Jordan) Physics B.Sc -1984.

Graduate Institution(s):

Middle East Technical University (Ankara-Turkey) Physics M.Sc - 1987.

Theoretical Condensed Matter Physics (Computational, Materials, Solid State).

Thesis Title:

Development of A Semi-Empirical Potential Energy Function: Application to Micro clusters.

M.Sc. GPA: 3.45 / 4.00.

Middle East Technical University (Ankara-Turkey) Physics Ph.D - 1993.

Theoretical Condensed Matter Physics (Computational, Materials, Solid State).

Thesis Title:

Molecular Dynamics Computer Simulation of Aluminum: Bulk, Surface, and Cluster Properties.

Ph.D. GPA: 3.55/4.00.

C. Languages:

*Mother tongue*	*Second language*	*Other languages*
Arabic / V. Good	English / V. Good	Turkish / Good

D. Present Position :

Associate Professor of Physics, Faculty of Science, Department of Basic Sciences-Mathematics, Philadelphia University, Aein Al-basha - Jordan.

E. Appointments:

No.	Employer	Position	Dates
1	University of Wisconsin-Milwaukee-USA	Visiting Scholar	2/7/2007-02/01/2008
2	Philadelphia University-Jordan	Associate Prof.	2005-to present
3	University of Wisconsin-Milwaukee-USA	Visiting Scholar	1/3/-30/9/2004
4	Philadelphia University-Jordan	Assistant Prof.	1998- 3/4/2005
5	Al-Albayt University –Jordan	Assistant Prof.	1995-1998
6	Al-Fateh Private .Libyan College-Turkey	Lecturer	1991-1993
7	Middle East Technical University-Turkey	Research Assistant	1989-1993
8	Yarmouk University-Jordan	Research Assistant	1984-1985

F. Honors, awards, fellowships and scholarships

Names	Dates
International Atomic Energy Agency (IAEA) Fellowship JOR/06037	2/7/2007-02/01/2008
University of Wisconsin-Madison - (SRC) USA, Honorary Fellowship	2/7/2007-02/01/2008
University of Wisconsin-Milwaukee-USA, Honorary Fellowship	2/7/2007-02/01/2008
National Science Foundation (NSF) Fellowship, at SRC-Madison, WI USA	Summer 2007&2008
National Science Foundation (NSF) Fellowship, at SRC-Madison, WI USA	1/3/2004-30/9/2004

G.Membership of Cultural, Educational and Professional Societies:

Member of

Petra School of Physics-Jordan.

International Pilot to Physics-through internet.

Center for Mathematical Sciences(AUB)-Lebanon.

The Royal Society for the Conservation of Nature-Jordan.

Al-Wahdat Cultural and Sports Club.

H. Publications:

Publications in Reviewed Journals

1. Z. El-Bayyari and Ş. Erkoç

Molecular-Dynamics Computer Simulation of Aluminum Clusters (Al_n; n=3-55):Empirical Many-Body Potential Energy

Function Calculation. Phys. Stat. Sol. (b) 170, 103 - 111 (1992).

http://www3.interscience.wiley.com/cgi-bin/abstract/112454791/ABSTRACT

2. Z. El-Bayyari and Ş. Erkoç

Bulk and Surface Properties of Aluminum: A Molecular-Dynamics Simulation, Materials Chemistry and Physics,

37, 382 - 388 (1994).

http://dx.doi.org/10.1016/0254-0584(94)90179-1

3. Z. El-bayyari

Molecular–Dynamics Computer Simulations of Silver Aggregates (Ag_n;n=3-13):Empirical Many-Body Potential Energy

Function Calculation. Phys. Stat. Sol. (b). 208, 339 – 347 (1998).

http://www3.interscience.wiley.com/cgi-bin/abstract/40001494/ABSTRACT

4. Mohammad A. Abadi and Z. El-Bayyari.

Screened Hydrogenic Calculations of the Photo-detachment Cross-Section of the Atomic Lithium Anion.

Mutah Lil- Buhūth Wad-Dirāsāt. 15, No. 4, 161-176 (2001).

http://www.mutah.edu.jo/dar/sciej.htm

5. Mohammad A. Abadi and Z. El-Bayyari .

The Absolute Threshold Photo-detachment Cross-Section of AL^-.

Mutah Lil-Buhūth Wad-Dirāsāt .16, No. 1, 83-95 (2001).

http://www.mutah.edu.jo/dar/sciej.htm

6. Z. El-Bayyari

Gold Microclusters (Au_n; n =3 - 13): A Molecular - Dynamics Computer Simulation. in “Computer

Simulation Studies in Condensed Matter Physics XIV, Eds. D. P. Landau, S. P. Lewis, and

H. B. Schüttler “, Vol. 89, Part II, Page 47, (Springer Verlag, Heidelberg, Berlin, 2001).

http://www.springer.com/east/home/

7. Z. El-Bayyari

Embryonic Form of Nickel and Palladium: A Molecular - Dynamics Computer Simulation in “Computer

Simulation Studies in Condensed Matter Physics XVII, Eds. D. P. Landau, S. P. Lewis

, and H. B. Schüttler “, Vol. 103, Page 205 ( Springer Verlag, Heidelberg, Berlin, 2004).

http://www.springer.com/east/home/materials?SGWID=5-10041-22-51644178-detailsPage=ppmmedia|toc

8. Z. El-Bayyari, Hüseyin Oymak and Hatice Kökten

On the Structure and Energetic Features of Small metal Clusters: Ni_n, Cu_n, Pd_n, Pt_n, and Pb_n, n=3-13.

International Journal of Modern Physics C, 15, 917-930 (2004).

http://ejournals.wspc.com.sg/ijmpc/15/1506/S0129183104006339.html

9. Z. El-Bayyari

Embryonic Forms of Nickel: A Molecular - Dynamics Computer Simulation.

Journal of Molecular Structure THEOCHEM, 716, 165-174 (2005).

http://dx.doi.org/10.1016/j.theochem.2004.12.010

10. Z. El-Bayyari

A comparison Study of Ni, Pd, Pt, and Pb Microclusters: A Molecular - Dynamics Computer Simulation.

Submitted for publication to the Journal of Material Chemistry and Physics.

http://www.elsevier.com/wps/find/journaldescription.cws_home/504097/description#description

11. Carol J. Hirschmugl, Z. El-bayyari, Maria Bunta, Justin B. Holt, and Mario Giordano. Analysis of the

nutritional status of algae by: Fourier Transform Infrared Chemical Imaging.

Infrared Physics & Technology, 49, 57- 63 (2006).

http://dx.doi.org/10.1016/j.infrared.2006.01.032

12. M. J. Nasse, R. Reininger, T. Kubala, S. Janowski, Z. El-Bayyari, and C. Hirschmugl. Synchrotron Infrared Microspectroscopy Imaging Using a Multi-Element Detector (IRMSI-MED) for Diffraction-Limited Chemical Imaging. In preparation.

13. Z. El-Bayyari, M. J. Nasse, R. Julian, A. Norici, S. Ratti,C. Hirschmugl,and M. Giordano. Rapid assessment of resource partitioning in algae with IR microspectroscopy. In preparation.

14. M. J. Nasse, Z. El-Bayyari, S. Ratti and C. Hirschmugl. Flow Cell Design for IR Microspectroscopy of Living Biological Cells. In preparation.

15. Z. El-Bayyari

Growth of copper aggregates: A Molecular - Dynamics Computer Simulation. In preparation.

Proceedings Presented in National Meetings:

1. Z. El-bayyari

Molecular–Dynamics Computer Simulation of Silver Aggregates (Ag_n; n =3-13): Empirical Many-Body Potential Energy Function Calculation. Third Symposium on Computational Condensed Matter Physics, 3 – 5 November 1997, Irbid – Jordan.

Proceedings Presented in International Meetings:

1. Z. El-Bayyari

Gold Micro-clusters (Au_n; n = 3 - 13): A Molecular - Dynamics Computer Simulation.

The 14^th Annual Workshop on Recent Developments in Computer Simulation Studies in Condensed Matter Physics, Center for Simulational Physics, University of Georgia-Athens, 19-24, Feb, 2001, USA.

2. Z. El-Bayyari

Embryonic Form of Nickel and Palladium: A Molecular - Dynamics Computer Simulation.

The 17^th Annual Workshop on Recent Developments in Computer Simulation Studies in Condensed Matter Physics, Center for Simulational Physics, University of Georgia-Athens, 16-20, Feb, 2004, USA

I. Teaching Activity:

(The language of instructions is Arabic and English):

- Research assistant: Yarmouk University, Irbid - Jordan.

Duration: One academic year (1985 - 1986).

- Research assistant: Middle East Technical University Ankara - Turkey.

Courses for undergraduates: - General physics, and freshman level Lab., including experiments on mechanics, electricity and magnetism.

Duration: Five academic years (1989 - 1993).

- Instructor at Al - Fateh private Libyan college in Ankara -Turkey: for calculus and general physics.

Duration: Two years (1991 - 1993).

- Supervisor: Ras Corporation (Robert Allen Services), Madison county, Madison, Al U.S.A

Duration: Two years (1993 - 1995).

- Assistant Professor at Al al - Bayt University, Mafraq - Jordan:

Undergraduate level: Mathematical physics, Physics of vibrations and waves,

General physics 101, General Physics 102, and Physics labs.

Graduate level: Mathematical Physics.

Duration: Three years (1995 - 1997).

- Assistant Professor - Philadelphia University, Sweileh - Jordan (1998 – 2005).

Undergraduate level: General Physics 101 and 102, Physics Mathematics 102 and Linear Algebra.

- Associate Professor - Philadelphia University, Sweileh - Jordan (2005 – to Present).

Undergraduate level: General Physics 211105 for Medicine and Pharmacy students,, Applied Physics 211104, and Preliminary Physics 211099.

Other Courses :

Quantum Mechanics, laser Physics, Atomic physics, Electrodynamics, classical mechanics, solid state physics, semiconductor physics.

J. Relevant Research Fields:

· Molecular-Dynamics Computer Simulation of Clusters, Surface and Bulk Properties of Condensed Matter.

· Development of Empirical Many - Body Potential Energy Function for Atomic Interactions.

· Variable Angle Spectroscopic Ellipsometry VASE.

· Infrared (IR) Microspectroscopy based on Synchrotron Radiation and its applications.

· Chemical imaging of biological living cells and human tissues.

· Raman Spectroscopy applied to biological cells, thin films and materials.

K. Seminars Presented:

1) Development of a Semi - Empirical Potential Energy Function: Applications to Micro-clusters. October 1987.

2) Basic Laser Principles. December 1988.

3) Absorption in Semiconductors. June 1989.

4) Theory of Charged Particle Excitation. June 1989.

5) Molecular Dynamics Computer Simulation of Aluminum: Bulk, Surface, and Cluster Properties. December 1992.

6) Computer Simulations in Physics. 12, Dec, 1995.

7) Clusters Condensed Matter in Embryonic Form. 14, April, 1996.

8) Cluster Models for Surface and Bulk Phenomena 20, Nov., 1996.

9) Variable Angle Spectroscopic Ellipsometery VASE. 7, May, 1997.

10) Potential Energy Functions Used in Computer Simulation of Materials 1, April, 1998.

11) Gold Micro-Clusters (Au_n; n=3-13) : A Molecular Dynamics computer Simulation. UGA-USA, 19-24, Feb, 2001.

12) Embryonic Form of Nickel and Palladium: A Molecular - Dynamics Computer Simulation.UGA-USA, 6-20, Feb, 2004.

13) Molecular dynamics computer simulation of bulk, surface, and clusters. UWM-USA, Sept.9, 2004.

14) Infrared spectromicroscopy and its applications to living cells. UWM-USA, Sept.9, 2004.

15) Infrared and its applications to microalgal cells, 3^rd SESAME users meeting, 11-13, October, 2004. Antalya-Turkey.

16) Rapid assessment of resource partitioning in algae with IR microspectroscopy, 4^th International Workshop on Infrared Microscopy and Spectroscopy with Accelerator Based Sources (WIRMS), September 24^th – 29^th , 2007. Awaji-Island, Hyogo - Japan.

L. Committees on the University, Faculty, and Department level:

1) Member of the scientific research committee (Al-albayt University).

2) Member for studying university tenders and equipment’s (Al-albayt University).

3) Member of library committee (Al-albayt University).

4) Member of the yearbook committee. (Al-albayt University and Philadelphia University).

5) Member of the university elections committee (Students affairs / Al-albayt University).

6) Department laboratories, equipment’s, and supplies committee (Physics Department / Al-albayt University).

7) Academic advisor for Graduate students (Physics Department / Al-albayt University).

8) Assistant Chairman for Department of basic sciences (Philadelphia University - labs affairs).

9) Member of the Seminars Committee (Philadelphia University).

10) Member of the Graduation Committee (Philadelphia University).

11) Member of the National Team on Synchrotron Radiation project in Jordan.

12) Member of the Jordanian National Scientific Committee- International Center on Synchrotron Radiation.

13) Member of the University Council (Philadelphia University 2003-2004,2005-2006).

14) Member of the XRF, EXAFS, and IR beamline groups , SESAME project-Jordan.

15) Member of the scientific research committee (Philadelphia University, 2003-2004-2005-2006-2007).

16) Member of the faculty of science council (Philadelphia University, 2006-2007).

17) Member of the Web and internet committee- Faculty of Science (Philadelphia University, 2006-2007).

18) Member of the Quality Assurance (QA) committee - Faculty of Science (Philadelphia University, 2007-2008).

M. Conferences:

1) International Conference on Beam Solid Interactions - Middle East Technical University - Ankara - Turkey. April, 24 - 28, 1989.

2) Second Symposium on Computational Condensed Matter Physics. Yarmouk University, Irbid - Jordan, 6 - 8, Nov., 1995.

3) First workshop on Space Communications. Al al - Bayt University, Mafraq - Jordan, 12, March, 1996.

4) International Cooperation Program of the EU and Al al - Bayt University on High Performance Computing. Mafraq - Jordan, 9 - 10, Sept, 1996.

5) Third Symposium on Computational Condensed Matter Physics. Yarmouk University, Irbid - Jordan, 3 - 5, Nov, 1997. In collaboration with International Center for Theoretical Physics (ICTP), Trieste, Italy.

6) First Workshop on Remote Sensing Sciences and Technology, Al - Bayt University, Mafraq - Jordan, 9 , December, 1997.

7) A Workshop on Magnetic Measurements for Characterization of Magnetic Materials and Their Quality as information Storage’s, Al - Bayt University, Mafraq - Jordan , 20, April, 1998.

8) Sixth Petra School of Physics - (Physics of Low Dimensional Systems) Organized by (CTAPS) Yarmouk University, Irbid - Jordan, 6 -13, September, 1998.

9) Third Symposium on Magnetics, Organized by (CTAPS) Yarmouk University, Irbid - Jordan, 2 -4, November, 1998.

10) Second Workshop on Properties and Applications of Thin Films, Organized by Alal-Bayt University, Mafraq- Jordan, 10 - 11 May, 1999.

11) Fourth Symposium on Condensed Matter Physics. Yarmouk University, Irbid - Jordan, 1 -3, Nov., 1999. In collaboration with International Center for Theoretical Physics (ICTP), Trieste, Italy.

12) The 14^th Annual Workshop on Recent Developments in Computer Simulation Studies in Condensed Matter Physics, Center for Simulational Physics, University of Georgia-Athens, 19-24, Feb, 2001, USA.

13) The International Symposium on Innovation in Information and Communication Technology (ISIICT 2002) Conference. Philadelphia University, Jerash – Jordan, May, 28-29, 2002.

14) The JSPS Asian Scientific seminar “ Synchrotron Radiation Science” at Al-Balqa Applied University, Al Salt- Jordan, October 19-28, 2002. In collaboration with the Japan Society for the Promotion of Science, and The High Energy Accelerator Research Organization, KEK, Japan.

15) Third Symposium on use of Nuclear Techniques in Environmental Studies, Organized by (CTAPS) Yarmouk University, Irbid - Jordan, 16-18, September, 2003.

16) The 17^th Annual Workshop on Recent Developments in Computer Simulation Studies in Condensed Matter Physics, Center for Simulational Physics, University of Georgia-Athens, 16-20, Feb, 2004, USA.

17) Müller lecture series & award ceremony, University of Wisconsin-Milwaukee USA 9-16/8/2004.

18) Frontiers in soft X-ray, VUV, and Infrared research, Sept. 16-18, 2004 University of Wisconsin-Madison USA.

19) Third Sesame user’s meeting 11-13 October, 2004. Antalya – Turkey.

20) The Second Conference on Scientific research in Jordan, Nov. 12, 2005, Jordan-University, Amman-Jordan.

21) The 4^th SESAME user’s meeting, Dec. 6-8, 2005. Amman-Jordan.

22) The first Jordanian workshop on “Synchrotron Radiation for Jordanian SESAME User’s “, Jordan University, Amman- Jordan,10-05-2006.

23) The Second Jordanian workshop “SESAME in Research, Training and Technological Applications” Applied Science University, Amman-Jordan, 10-12-Septemper 2006.

24) 4^th International Workshop on Infrared microscopy and Spectroscopy with Accelerator Based Sources (WIRMS), September 24^th – 29^th, 2007. Awaji-Island , Hyogo-Japan. http://www.uvsor.ims.ac.jp/WIRMS2007/

25) Plans for the Wisconsin Free Electron Laser Facility: Preliminary Design Performance and Scientific Opportunities (WiFEL), October 11, 2007, University of Wisconsin-Madison, USA. http://www.wifel.wisc.edu/symposium07/index.htm

26) Synchrotron Radiation Center User’s Meeting, October 12^th-13^th, 2007, University of Wisconsin-Madison, USA. http://www.src.wisc.edu/meetings/um2007/index.htm

N. Collaborators & Other Affiliations:

(i) Collaborators:

(1) Prof. Carol J. Hirschmugl – Physics Department – University of Wisconsin –Milwaukee (P.O. Box 413, Phone: 414-2295748, Fax: 414-2295589 e-mail: cjhirsch@uwm.edu

(2) Prof. Mohammad A. Abadi – Physics Department- Mu’tah University – Kerak – Jordan (P. O. Box 7, Phone: +962-6- 4617860, Fax: + 962-6- 4654061 e-mail: maabbadi@mutah.edu.jo

(ii) Graduate and Postdoctoral Advisors:

1. Prof. Dr. Sakir Erkoc, Physics Department, Middle East Technical University

06531 Ankara - Turkey.

MSc. and Ph.D. Supervisor

Direct Telephone: + 90 - 312 - 2103285

Fax : + 90 - 312 - 2105099

e - mail : erkoc@metu.edu.tr

WWW : www.physics.metu.edu.tr/~erkoc/

O. Other Professional Qualifications:

Good knowledge and experience in computers including computer languages FORTRAN and Basic. The systems I worked on are:

(1) Personal Computer (PC’s)

(Tex , Latex , Pctex , Miktex, Grapher, Windows, Dos, Norton Utilities, Gnu-plot, Pw, Igor, Omnic, Atlus, Cytospec, Easy plot , Macromedia Flash Mx, Fireworks Mx, Dreamweaver Mx , and other software’s).

(2) Internet and other software’s

(3) Unisys A9F system (Burroughs 6930).

(4) IBM (3090), VM / XA SP and CMS.

(5) UNIX AIX version 3.2.5 system.

P. Synergistic Activities:

Establishment of Physics Department including the study plans and curriculums for the undergraduate and graduate studies at Al-Albayt University in Mafaraq-Jordan.
Establishment of an interactive undergraduate learning scientific teaching lab including computational tools at the Physics Department - al-Albayt University in Jordan.
Preparing research labs for postgraduate studies at the Physics Department , Al-albayt University (Jordan) with the most sophisticated modern computerized systems (i.e.: VSM, VASE, XRF, …etc).
Preparing curriculums according to the quality assurance committee requirements at the faculty of science–Philadelphia University (Jordan) for excellence in teaching.
Organizing a series of seminars by inviting a well known professors in different fields to give talks at our campus- one of them on SR radiation by (Prof. D. Eienfeld) (as a member of the national team for Synchrotron Radiation in Jordan).
Owner and founder of the Sesame Infrared beam line group at Yahoo:

(http://groups.yahoo.com/group/Sesame_IR).

Owner and founder of the Sesame medical beam line group at Yahoo:

(http://groups.yahoo.com/group/Sesame_MBL).

Q. References:

1- Prof. Sakir Erkoc, Physics Department, Middle East Technical University

06531 Ankara - Turkey.

MSc. and Ph.D. Supervisor

Direct Telephone: + 90 - 312 - 2103285

Fax : + 90 - 312 - 2105099

e - mail : erkoc@metu.edu.tr

WWW : www.physics.metu.edu.tr/~erkoc/

2- Prof. Carol Hirschmugl – University of Wisconsin-Milwaukee- College of Letters and Sciences-Department of Physics- P. O. Box 413, Milwaukee, WI 53201-0413, USA

Phone : + 414-229-5748

Fax : + 414-229-5589

e-mail : cjhirsch@uwm.edu

3- Prof. Imad Abu-Khalaf

e-mail: imadabukhalaf@yahoo.com

e-mail: imadabukhalaf@hotmail.com

R. M.Sc and Ph. D. Abstracts:

ABSTRACT

DEVELOPMENT OF A SEMI-EMPIRICAL POTENTIAL ENERGY FUNCTION:

APPLICATIONS TO MICROCLUSTERS

Zuheir El-bayyari

M.S in physics

Supervisor: Assoc. Prof. Dr. Şaker Erkoç

1987, 191 pages.

Many-body effects are essential for the description of atomic clusters for most real materials. We have developed a Potential Energy Function (PEF) which includes the many-body effect via a parameterized three-body term. Thus, the present (PEF) includes both two- , and three-body terms parameterized to fit cluster and bulk thermodynamic data for their respective systems.

Using the definition of cohesive energy, stability condition for crystals, and the bulk modulus we solve for the PEF parameters, which are used in the cluster calculations, for binding energies and bond lengths. A parametrical analysis was performed to investigate the energetically most stable micro-cluster structures for different elements as Al, Cu, Ni, Au, Fe, and Si composed of three and four atoms.

ABSTRACT

MOLECULAR-DYNAMICS COMPUTER SIMULATION OF ALUMINUM:

BULK, SURFACE, AND CLUSTER PROPERTIES

El-bayyari, Zuheir Subhi

Ph. D. in Physics

Supervisor: Prof. Dr. Şaker Erkoç

April, 1993, 46 pages.

We have investigated the bulk, surface and cluster properties of aluminum using the Molecular-Dynamics technique. In the simulation a recently developed empirical many- body potential energy function has been used, which contains two- and three- body atomic interactions. The bulk properties specific heat capacity, and vacancy formation energy have been calculated, and the surface properties surface energy, surface vacancy, and ad-atoms on the (001) surface have been investigated. For clusters the structural stability and energetics of Al_n (n=3-55) clusters have been investigated at low temperature, T= 1 K. It has been found that the energetically most stable structures of aluminum clusters are in compact distorted buckled form. For bulk, surface and cluster properties the present results are qualitatively in agreement with available literature values.

Keywords: Molecular-Dynamics Simulation, Empirical Many-Body Potential Energy Function, Nordsieck-Gear Algorithm, Aluminum Properties, Bulk, Surface, Cluster.

Science Code: 404.05.01