COURSES

Must Courses for M.Sc. Program

• AMN500        Seminar
• AMN501        Materials Science and Engineering
• AMN502        Nanoscience and Nanotechnology
• AMN597        Special Topics
• AMN599        Master Thesis

Must Courses for Ph.D. Program

• MSME600     Seminar
• MSME697     Special Topics
• MSME699     Ph.D. Thesis

Elective Courses for M.Sc. and Ph.D.Programs

• AMN503        Polymer Chemistry and Physics
• AMN504        Polymer Science and Technology
• AMN505        Smart Materials and Structures
• AMN506        Nanofabrication
• AMN507        Surface Science
• AMN508        Surface Modification
• AMN509        Biomedical Polymers
• AMN510        Biomaterials
• AMN511        Biosensors
• AMN512        Advanced Materials Design for Tissue Engineering
• AMN513        Engineering of Nanostructures for Targeted Drug Delivery
• AMN514        Tissue Engineering
• AMN515        Advanced Instrumental Analysis-I
• AMN516        Advanced Instrumental Analysis-II
• AMN517        Thermodynamics for Material Science
• AMN518        Chemical Kinetics and Dynamics
• AMN519        Quantum Theory of Materials
• AMN520        Organic Electronics
• AMN521        Solid State Physics
• AMN522        Physics of Metals and Alloys
• AMN523        Physics of Semiconductors
• AMN524        Optical Properties of Semiconductors
• AMN525        Semiconductor Quantum Nanostructures – I
• AMN526        Semiconductor Quantum Nanostructures – II
• AMN527        Computational Methods in Quantum Nanostructures
• AMN528        Fuel Cell Science and Technology
• AMN529        Surface Coating
• AMN530        Thin Film Solar Cells
• AMN531        Plasma Technology for Materials
• AMN532        Electrochemical Engineering
• AMN533        Processing and Characterization of Ceramic Materials
• AMN534        Sol-Gel Processing of Ceramics
• AMN535        Membrane Separations in Aquatic Systems
• AMN536        Environmental Nanotechnology
• AMN537        Packaging Materials Technology
• AMN538        Materials Science of Concrete
• AMN539        Analytical Techniques in Concrete Technology
• AMN540        Numerical Methods for Engineers
• AMN541        Statistical Data Analysis
• AMN542        Data Mining
• AMN543        Computational Methods in Physics, Chemistry and Biology
• AMN544        Advanced Computational Chemistry
• AMN545        Introduction to Molecular Modeling
• AMN546        Object Oriented Programming Languages and Systems
• AMN547        Finite Element Methods
• AMN548        Basic Patent Principles in Science and Engineering
• AMN549        Ethics in Science
• AMN550        Membrane Technology
• AMN551        Nanotechnology Applications in Food Processing
• AMN552        Molecular Photochemistry
• AMN553        Coordination Chemistry
• AMN554        Flat Panel Display Technologies
• AMN555        Quantum Mechanics for Engineers
• MSME601     Materials Science for Engineers
• MSME602     Thermodynamics of Materials
• MSME603     Mechanical Properties of Materials
• MSME604     Electronic Materials
• MSME605     Composite Materials
• MSME610     Chemistry and Physics of Surfaces and Interfaces
• MSME620     Materials Characterization Techniques I
• MSME621     Materials Characterization Techniques II
• MSME630     Soft Nanomaterials
• MSME650     Nonlinear Finite Elements
• MSME651     Continuum Mechanics
• MSME652     Theory of Elasticity
• MSME653     Numerical Method
• MSME654     Advanced Dynamics
• MSME655     Combustio
• MSME656     Mechatronics
• MSME657     Micromechanics of Materials
• MSME658     Acoustics
• MSME659     Robotics
• MSME660     Theory of Plasticity
• MSME661      Heat and Mass Transfer
• MSME662     Advanced Numerical Methods
• MSME663     Nonlinear Dynamics
• MSME664     Nonlinear Elasticity
• MSME665     Wave Propagation in Elastic Media
• MSME666     Random Oscillations of Mechanical Systems
• MSME667     Nano/Micro Mechanical Systems
• MSME668     Mechanics of Composites
• MSME669     Tribology

AMN501. Materials Science and Engineering
Introduction and historical perspective to materials science and engineering. Atomic structures and interatomic bonding, the structure of crystalline solids, imperfections in solids, diffusion, mechanical properties of materials, phase diagrams. Properties, applications and processing of metal alloys, ceramics and polymers. Electrical, thermal, magnetic and optical properties of materials.

AMN502. Nanoscience and Nanotechnology
History of nanoscience and nanotechnology. Basic concepts in nanoworld. Quantum mechanics, statistical mechanics and chemical kinetics. Nanofabrication tools: top down and bottom up approaches. Nanostructures. Application of nanomaterials. Nanobiotechnology. Tools to characterize nanomaterials.

AMN503. Polymer Chemistry and Physics
Basic concepts of polymer science. Microstructure and molecular weight. Chemical bonding and polymer structure. Step-growth and addition polymerization. Polymerization kinetics. Probability and statistics of polymerizations. Stereochemistry of polymerization. Reactions of polymers.Ideal and real chains. Thermodynamics of polymer solutions and blends. Flory-Huggins equation and cohesive energy density. Random branching and gelation. Predicting polymer properties by computational methods.

AMN504. Polymer Science and Technology
Polymer terminology, nomenclature. Stereochemistry in polymers, conformation, configuration, isomerization, optical activity. Morphology of polymers, crystaline, amorphous    and    semi- crystalline   polymers,   glass-transition   temperature,   meltingtemperature.   Methods   for   the molecular weight determination of polymers, colligative properties and molecular weight, size- exclusion chromatography, light-scattering, etc. Mechanical properties and other properties of polymers. Polymerization reactions, radical polymerization, addition polymerization, condensation polymerization, etc. Polymerization processes, bulk, solution, suspension, emulsion polymerizations. Processing of polymers.

AMN505. Smart Materials and Structures
This course is designed to give an insight into the latest developments regarding smart materials and their use in structures. Further, this also deals with structures which can self adjust   their stiffness  with  load.  Students  will  learn  (1)  the  fundamentals  of  smart materials, devices and electronics, in particular those related to the development of smart structures and products; and (2) the skills, knowledge and motivation in the design, analysis and manufacturing of smart structures and products. After an elaborate introduction of different groups of smart materials, the course will focus on analysis, design, and implementation of smart structures and systems: modeling  of  beams  and  plates  with  induced  strain  actuation,  piezoelectric  ceramics  and polymers, shape memory alloys,      electro-rheological      fluids.      Piezoelectric      and magnetostrictive      sensors      and  actuators,  and  fiber  optic  sensors.  Integration  mechanics. Damage detection and repair. Applications.

AMN506. Nanofabrication
Lithography, optical and e-beam lithography; X-ray lithography, focused-ion lithography, soft lithography, imprinting lithography, Thin film deposition, physical vapor deposition, chemical vapor deposition; Etching: wet and dry; Self-assembling; Microelectromechanical systems

AMN507. Surface Science
This course covers the fundamental principles needed to understand the properties of the surfaces of materials, with emphasis on structure, electronic, chemical, mechanical and optical properties. Topics include: Stability of surfaces, atomic structure in relation to the bulk, restructuring and reconstruction. Adsorption of atoms and molecules, surface chemistry and material growth. The course covers some of the most important tools for the characterization of surfaces, such as electron   and   x-ray  diffraction,   electron   spectroscopies   (Auger   and   x-ray  photoelectron spectroscopy), Scanning Tunneling and Force Microscopy.

AMN508. Surface Modification
Plasma  treatment  and  deposition;  radiation  grafting
;  chemical  reaction  of  the  surface; ozonolysis; photoreaction; ion implantation; ion etching; solvent cast films; surface active modifiers (low and high MW); metallization; self assembly; micro-contact printing; immobilization of biomolecules

AMN509. Biomedical Polymers
Introduction, natural and synthetic polymers, advantages/disadvantages. Chitosan, alginate, cellulose, collagen, starch, gelatin, biodegradable polymers, silicones, PET, PTFE, PU, polyamides, acrylate-based polymers. Applications of biomedical polymers; in orthopedic devices, dental applications, adhesives, controlled release, sutures, vascular grafts, wound dressings, gene delivery.

AMN510. Biomaterials
Introduction, definition of biomaterial, classification, main applications. Surface properties of biomaterials, technics for surface characterization. Mechanical and other properties. Materials used as biomaterial; metals, ceramics, composites, polymers. Tissue response; coagulation, immune response, foreign body reaction. Examples of biomaterial applications.

AMN511. Biosensors
Underlying engineering principles used to detect small molecules, DNA, proteins, and cells in the context of applications in diagnostic testing, pharmaceutical research, and environmental monitoring.   Biosensor   approaches   including   electrochemistry, fluorescence, acoustics, and optics; aspects of selective surface chemistry including methods for biomolecule attachment to transducer surfaces; characterization of biosensor performance; blood glucose detection; fluorescent DNA microarrays; label-free biochips; bead-based assay methods. Case studies and analysis of commercial biosensors.

AMN512. Advanced Materials Design for Tissue Engineering
Definition of tissue engineering; definition of scaffold; cells, scaffold, biosignal molecules relationship. Scaffold design, methods for scaffold fabrication. Salt (particulate) leaching, ice- particle  leaching,  gas-foaming,  particle  aggregation,  freeze  drying,  thermally induced  phase separation, centrifugation, supercritical carbon dioxide, fiber production, electrospinning, solid freeform fabrication, 3D printing, etc. Bioplotter. nanopatterning, microcontact printing.

AMN513. Engineering of Nanostructures for Targeted Drug Delivery
Materials used for nanocarriers; nanostructures' surface functionalization; delivery and targeting strategies; immobilization, engineering of stealth nano vehicles for cellular delivery; quantum dots  for  nuclear  and  cytoplasmic  visualization;  Examples  of  FDA  approved  nanodrugs  in addition to nano formulations at the pre-clinical and clinical stages.

AMN514. Tissue Engineering
Principles and applications of tissue engineering for regeneration of tissues and organs will be discussed. The strategies for production of cell carrying scaffolds, rationale for their design, material choices, and their biological, chemical, and mechanical properties will be covered. Selection  of  cell  sources  and  stem  cells,  in  vitro  culture  conditions,  and  tissue  engineered products and problems in their clinical utilization will be discussed.

AMN515. Advanced Instrumental Analysis-I
This course presents a survey of instrumental methods of chemical analysis and focuses on understanding the fundamental principles underlying instrumental methods and their realization in modern instrumentation for chemical analysis. Students will develop an understanding of the analytical capabilities of a number of instrumental methods and be able to suggest suitable instrumental methods for particular analytical problems. The main objective of instrumental analysis is to learn the theory of operation for several types of instruments used for chemical measurements in the analytical sciences. Lecture topics cover electroanalytical chemistry (potentiometry, voltammetry), separation methods (GC, LC, HPLC), and mass spectrometry. In the laboratory, students gain hands-on experience both by performing selected basic chemical determinations and by undertaking special projects.

AMN516. Advanced Instrumental Analysis-II
Advanced  Instrumental  Analysis  -  II  is  a  one-semester  course  that  extends  the  range  of laboratory skills and knowledge of chemistry the student has gained in prior years with more advanced skills, advanced topics and new concepts in chemical spectroscopic analysis. Lecture topics cover  atomic spectroscopy (AAS, AES, and ICP-MS), molecular spectroscopy (UV-VIS, IR, fluorescence and Raman spectroscopy), nuclear magnetic resonance spectroscopy, and X-ray spectrometry.

AMN517. Thermodynamics for Material Science
Introduction to thermodynamic concepts. Properties of gases. First law of thermodynamics  and concepts of work, heat, internal energy and enthalpy. State functions. Second law of thermodynamics  and  entropy change.  Engineering cycles:  the Carnot  cycle,  Otto  cycle etc. Physical transformations of pure systems. Simple mixtures, chemical equilibrium and Gibbs free energy.

AMN518. Chemical Kinetics and Dynamics
Review of rate laws, elementary reactions and complex reactions, Experimental methods in gas and fast reactions in solution, Enzyme catalyzed reactions, Autocatalysis, Theoretical interpretation   of   reaction   rates   (   including   Rice-Ramsperger-Kassel   (RRK)   and   Rice- Ramsperger-Kassel-Marcus (RRKM) theories), Potential energy surfaces, and Photodissociation, Theories of reaction rates, Solution kinetics

AMN519. Quantum Theory of Materials
Review   of   mathematical   concepts,   Historical   background   of   Quantum   Mechanics,   the Schrödinger  Equation,  Postulates  of  Quantum  Mechanics,   Linear  and  Hermitian operators, Commutation of operators, the Uncertainty Principle, Pauli’s Exclusion principle, Some exactly soluble problems, Approximate methods, Introduction to Time- dependent Quantum Mechanics.

AMN520. Organic Electronics
Basic concepts in organic chemistry and physical organic chemistry. Introduction to organic electronics. Electronic transport in crystalline organic materials. Basics of light emission and polarization. Conducting polymers. Organic field effect transistors. Organic and polymer light emitting diodes. Organic solar cells.

AMN521 Solid State Physics
Crystal structures, fundamental types of lattices, wave diffraction and reciprocal lattice, Brillion zones,  crystal  bindings,  crystal  vibrations,  thermal  properties,  free electron  Fermi  gas,  heat capacity of the electron gas, electrical conductivity, energy bands of solids.

AMN522. Physics of Metals and Alloys
Crystal  structures  of  metals,  electronic  structures  of  metals,  thermal  properties  of  metals, electrical properties of metals, magnetic and nonmagnetic metals, transport properties of metals, phonons in metals, alloys

AMN523. Physics of Semiconductors
Crystals,   band gap, effective mass in semiconductors, intrinsic carriers,   impurities in semiconductors,   ionization of donor or acceptors, thermo electric effects, amorphous semiconductors, transport in semiconductors, device applications of semiconductors.

AMN524. Optical Properties of Semiconductors
Reflection and absorption coefficients, direct and indirect optical transition, impurity absorption, intraband optical transitions, interband optical absorption, optical transitions associated with electron–hole pair, excitons, phonon effects, devices applications.

AMN525. Semiconductor Quantum Nanostructures – I
This course focuses on an introduction to quantum nanostructures. In this context, effects of the reduced dimensions of the bulk semiconductors, introduction to quantum mechanics, solution of Schrodinger equations, electrons and phonons in periodic potentials, quantum wells, quantum wires, quantum dots, fabrication of quantum nanostructures.

AMN526 Semiconductor Quantum Nanostructures – II
This   course   will   cover   subjects   of   an   impurity   problem   in   semiconductor   quantum nanostructures, many-electron quantum nanostructure, excitons in a quantum nanostructure, optical transitions, and device applications.

AMN527 Computational Methods in Quantum Nanostructures
Semiconductor quantum wells, wires and dots, analytical solution in quantum heterostructures with single particle, electronic structure calculations with variational methods,  application  of genetic  algorithm  to   quantum  heterostructures,  electronic structure calculations with finite difference methods, shooting methods and matrix diagonalization methods, electronic properties of many-electron heterostructures, self- consistent solution of Poisson-Schrödinger equations

AMN528. Fuel Cell Science and Technology
Basic concepts of electrochemistry. Fuel cell principles, fuel cell thermodynamics, fuel cell reaction  kinetics,  fuel  cell  charge  transport  and  fuel  cell  characterization.  Fuel  cell  types: polymer electrolyte membrane fuel cells, direct methanol fuel cells, solid oxide fuel cells, phosphoric acid fuel cell, alkaline fuel cell and molten carbonate fuel cell. Fabrication of fuel cell components. Applications of fuel cell devices. Fuels for fuel cell systems.

AMN529. Surface Coating
Role of surface coating and surface modification technologies in obtaining required surface characteristics of a product. Different surface coating technologies: chemical vapor deposition, physical vapor deposition, electro deposition, electroless deposition, thermal spray processes, coating deposition by wetting. Principle of various coating processes.   Various   process parameters  controlling  the  yield  of  coating  and  various surface properties of the coating. Criteria for selection of a surface coating technology. Product oriented surface coating technolgy. Different coating systems and function of various   elements   of   coating   systems.   Substrate technology    and    its    significance    in  obtaining  high  performance  coating.  Physical  and mechanical characterization of coating. Various methods for evaluating the performance of the coating.

AMN530. Thin Film Solar Cells
Basic principles of photovoltaic. Characterization of solar cells. The physics of the solar cell. Crystalline  silicon  thin  film  solar  cells.  Amorphous  silicon  thin  film  solar  cells.  Cadmium telluride  solar  cells.  Dye-sensitized  solar  cells.  Organic  solar  cells.  Transparent  conducting oxides for photovoltaics. Solar fuels.

AMN531. Plasma Technology for Materials
This course focuses on to acquire a thorough level of understanding of plasma applications in materials technology (e.g. surface engineering), environmental technology (e.g. gas cleaning) and energy production (nuclear fusion). Plasma technology: Plasma sources, Plasma-chemical reactions, Applications in materials technology, Applications in    environmental    technology, Lasers and light sources, Aeronautic and space applications, Nuclear fusion applications.

AMN532. Electrochemical Engineering
Basic   concepts   in   electrochemistry.   Electrochemical   stoichiometry,   thermodynamics   and kinetics. Mass and charge transport. Electrochemical characterization techniques: cyclic voltammetry, rotating disc electrodes, impedance spectroscopy etc. Electrochemical systems: electroplating, batteries, fuel cells, electrolysis, corrosion and electrochemical sensors.

AMN533. Processing and Characterization of Ceramic Materials
An introduction to ceramic materials. The properties of industrial ceramics. General methods for processing of ceramic materials. Characterization techniques for ceramic materials.

AMN534. Sol-Gel Processing of Ceramics
Introduction to sol-gel method. Types of precursors. Important parameters for sol preparation. Processing sol for various applications. Sol-gel transformation and heat treatment. Characterization of sol-gel processed ceramics.

AMN535. Membrane Separations in Aquatic Systems
General introduction to membrane materials, structures and membrane preparation techniques will  be  given  first.   Then  the  course  will  focus  on   membrane  modules, transport and fouling  phenomena,  and  process  engineering  fundamentals  of  membrane  processes  used  in aquatic systems. Individual student term projects will be given on advanced membrane processes such as nanocomposite membranes, forward osmosis, membrane bioreactors, pervaporation, membrane distillation, fuel cells, and membrane- based water quality sensors, etc.

AMN536. Environmental Nanotechnology
This course introduces a brief introduction properties, synthesis, characterization of nanomaterials, and their interacts with the natural world. Then the course will focus on environmental transport, toxicity, and removal of nanomaterials. Besides these applications (catalysis, sensing, treatment, and remediation) in environmental systems for nanotechnology will be given. The possible nanotechnology-based solutions to environmental problems will be prepared and presented by the students as a term project in the course.

AMN537. Packaging Materials Technology
Fundamental characteristics and applications of various materials and systems used to package perishable products such as food and pharmaceuticals. Product/package interactions and packaging  requirements  to  address  basic  theory  in  food  and  pharmaceutical  protection. Innovative approaches for novel, multifunctional, environmentally friendly packaging materials and techniques.

AMN538. Materials Science of Concrete
Manufacture, composition and specifications of Portland cement, Portland cement hydration, microstructure of concrete, fresh and hardened properties of concrete and testing, supplementary cementing  materials  and  blended  cements,  chemical  admixtures,  concrete  at  early  ages, durability issues of concrete.

AMN539. Analytical Techniques in Concrete Technology
Chemical, mineralogical and physical characterization of Portland cement and supplementary cementing materials (wet chemical analysis, XRF, XRD and laser diffraction techniques), rheological analysis of fresh mixtures of cement pastes, mortar and concrete, techniques for characterization of hardened cement paste, mortar and concrete samples; thermal analyses, XRD, SEM, mercury porosimetry.

AMN540. Numerical Methods for Engineers
The course of ‘numerical methods’ has the aim of how functions, derivatives, integrals, and differential equations are handled as strings of numbers in computers. Most scientists and engineers  are sooner or later faced with computing  tasks  that  require  some knowledge of this course. Thus, in this course, students will learn the topics of (1) introduction for numerical methods, (2) solution of equations by iterations, (3) solution of systems of linear equations, (4) eigenvalues and eigenvectors of a symmetric matrix, (4) interpolation of data, (5) numerical integration(I), (6) numerical integration(II), (7) initial value  problems  for  ODEs,  (8)  boundary value   problems   for   ODEs,   (9)   linear   and parabolic regression, and (10) finite difference methods.

AMN541. Statistical Data Analysis
This course introduces computer aided statistical analysis of data concepts. Creating and editing a data file, managing data: listing cases, replacing missing values, computing new variables, recoding variables, exploring data, selecting cases, sorting cases, merging files, creating   and editing   graphs   and   charts,   measures   of   central   tendency,   variability, deviation from normality,  size,  and  stability,  bivariate  correlations,  partial  correlations,  and  the  correlation matrix,  independent-samples,  paired-samples,  and  one-sample  tests,  one-way  analysis  of variance, simple linear regression, multiple regression analysis, general linear models: two-way analysis of variance, general linear models: three-way analysis of variance and the influence of covariates, reliability analysis: coefficient alpha and split-half reliability, discriminant analysis and cluster analysis are the concepts covered in this course.

AMN542. Data Mining
This course introduces data mining and data warehousing concepts. Data warehousing, OLAP technology, data preparation, association rule mining, classification and prediction, clustering, mining complex types of data, web mining, multi‐relational data mining are the concepts covered in this course.

AMN543. Computational Methods in Physics, Chemistry and Biology
Numerical    solution    of    Schrödinger    equation,    approximate    methods,    perturbation methods, variation methods, matrix methods, formation of matrix equations, solution of matrix equations,  stochastic  methods,  evolutionary  methods,  genetic  algorithms,  reproduction  and natural selection, computer implementation of genetic algorithms.

AMN544. Advanced Computational Chemistry
The course focuses on learning the principles of computational chemistry and computer- based molecular design. Both molecular mechanical and quantum mechanical models are covered. Students will learn a variety of commonly used techniques, such as geometry optimization, location of transition states, conformational analysis, and prediction of molecular and spectroscopic properties. Students will learn basics of implementing key algorithms, such as Newton-Rhapson minimization, and normal mode analysis of vibrational motions. Students also will become familiar with different software packages, including general model building and quantum chemical calculations. Students who complete the course are expected to be able to ask questions that can be solved with modern computational approaches and choose right computational tools to assist in their current or future research.

AMN545. Introduction to Molecular Modeling
Concepts of molecular mechanics and electronic structure theory and applications to practical chemical questions. Topics will include prediction of conformational preferences, reactivity, and selectivity,  use   of  commercial  databases  available (Cambridge   Structural    Database   and others),  structure-based  and  mechanism- based design methods, and combinatorial techniques.

AMN546. Object Oriented Programming Languages and Systems
This course introduces object-oriented programming languages and systems concepts. Abstraction, approaches  to modular program design, principles of abstract data types,  local variables and methods, classes and instances, single and multiple inheritance and object hierarchies, principles of object-oriented software development, overview of and experience with the object-oriented programming environments such as C++, Java are the concepts covered in this course. Programming assignments and possibly a term project are included in this course.

AMN547. Finite Element Methods
By using physical explanations of the course, finite element methods, it is focused on modern practical finite element methods (FEM) for solids and fluids. The analysis procedures are used extensively in the various fields of engineering and science. Thus, in this course, students can obtain the opportunities of learning the topics of (1) basic concepts of FEM, (2) general stiffness analysis, (3) FE for bar elements, (4) triangular FE for plane elasticity, (5) rectangular FE for plain elasticity, (6) rectangular FE for plate flexure, (7) triangular FE for plate flexure, (8) shell structures for rectangular FE, and (10) computer implementation of FEM.

AMN548. Basic Patent Principles in Science and Engineering
This course will provide an introduction to the basic principles of the national and international patent systems. It covers the function of the patent system; the nature of patents as property and as  legal  instruments;  comparisons  with  other  forms  of  intellectual  property;  subject  matter eligible for patenting; the conditions for patentability of an invention; and the disclosure requirements for a patent application. This course mainly focuses on the preparation technics of a patent application. The students will each be assigned  an  case  study,  and  will  write  a  patent application  draft.  Students  will  be instructed  as  to  best  practices  drafting  the  application, and  then  will  be  critiqued regarding written patent applications. The patent applications will be written in stages, including invention disclosure considerations, drawings, claims, and specification, with critique on each step in the process.

AMN549. Ethics in Science
This course will be a survey of the main ethical issues in scientific research. Discussion of  the integrity  of  the  scientific  literature  and  the  responsibilities  of  scientists  to associates and the public. Examination of principles and of case studies with an emphasis on the physical sciences. Topics to be covered include data fabrication, data falsification, plagiarism, conflicts of interest, data management, mentor and trainee responsibilities, collaborative research, authorship and publication, peer review, animal experimentation, and human experimentation.