Under the sponsorship of two National Science Foundation (NSF) Combined Research and Curriculum awards at New Jersey Institute of Technology, we are developing a program in Optical Science and Engineering and another in Particle Technology. The principal objective of each is to integrate current research into the curriculum and thereby address the urgent need for undergraduate and graduate education in these emerging areas of industrial and national importance. Each program involves a sequence of courses offered at the undergraduate and graduate level as well as complete laboratory environments. Due to the interdisciplinary nature of Particle Technology with its tremendous industrial relevance, and the numerous applications of Optical Science to many different engineering and scientific disciplines, faculty from several departments are involved in these program.

MULTI-DISCIPLINARY OPTICAL SCIENCE AND ENGINEERING

A 1994 NSF workshop on "Optical Science and Engineering: New Directions and Opportunities in Research and Education" recommended an emphasis in optics research and education because "Optical Science and Engineering is an enabling technology - that is, a technology with applications to many scientific disciplines and with the potential to contribute in significant ways to those disciplines. " The workshop on Optical Science and Engineering identified a number of critical challenges in Optical Science and Engineering which could lead to significant research and educational opportunities for the programs of NSF. "Research in Optical Sciences and Engineering holds exceptional promise for innovation that will have impact on long-term national goals. " Many of those areas highlighted by that workshop review - optical and photonic material and devices, fundamental optical interactions, instrumentation and sensing - are strongly represented in the research of the participating faculty. In addition to its 'enabling' aspects, optics technology represents viable employment potential for new graduates. Tn an American Institute of Physics survey of initial employment of 1992 Ph.D. recipients, the Education and Employment Statistics Division found that the percentage of graduates who obtained potentially permanent positions differed strongly by subfield: Only 14% of astrophysicists found permanent jobs immediately after obtaining PhDs, compared with 75% of those who study optics or lasers [1].

Fig. 1

The objective of this program is to (1) provide a unified, multidepartmental optical science/ engineering curriculum and (2) emphasize optics courses which will provide laboratory and classroom training to undergraduate and graduate students in emerging areas of industrial and national importance. In particular, our efforts are focused on the collective strengths of the Engineering School and the Applied Physics Programs: Environmental monitoring and detection of pollutants, industrial process monitoring, optoelectronics, and ultrafast optics and optoelectronics. This multidisciplinary program focuses on optical science and technology as an enabling technology: A technology with applications to many different engineering and scientific disciplines and the potential for significant contributions to those disciplines.

A. Laboratory Facilities and Structure

As part of this program development, 2000 square feet of laboratory space has been renovated to house the new Optical Science and Engineering Laboratory (Fig. 1). This student laboratory includes five 4' by 8' floating optical tables, separate work benches, He-Ne lasers, optics mounts, lenses, mirrors, photodetectors, spectrometers, and other optical components. As shown in the figure, one section of the lab is equipped with movable chairs for classroom lectures. Students use the work benches for assembling optical components, soldering, sample preparation, etc. Each optical table has its own portable computer equipped with GPIB and RS232 interfaces and a portable equipment rack on wheels for storing electronics such as lock-in amplifiers, oscilloscopes, power supplies, etc.. Wherever appropriate, the laboratory equipment is interfaced to the computer for easy experimental control, data acquisition, and data analysis. The portability of the computer and equipment rack permits students optimal access to the optical table. In the undergraduate lab, class size is limited to a maximum of two students per optical table (l0 students per section) to ensure that students get extensive, hands on experience in setting up, diagnosing, and testing optical components and systems. Currently, the only type of laser source used in the undergraduate laboratories is the He-Ne laser which is safe, easy to use, and inexpensive. The graduate student laboratory utilizes advanced laser systems such as excimer, YAG, and Ti:Sapphire lasers.

B. Curriculum Development

The following is an overview of the three courses including contributions from all five faculty participants. Updated course outlines and laboratory procedures may be accessed through the OPSE web page URL http://www.njit.edu/Directory/Centers/OPSE.

The curriculum development focuses on the theme of teaching optical science and engineering as an enabling technology. Students will learn not only the fundamental principles of optical science and engineering, but also technologically relevant applications of those principles to optoelectronics, environmental monitoring, industrial process monitoring and position control, and ultrafast optical and optoelectronic phenomena. The students' majors include applied physics, chemistry, chemical engineering, electrical engineering, engineering science, environmental engineering, pre-medical, computer engineering, and computer science. With such a menagerie of student backgrounds, two difficulties arise: (1) scheduling (2) varying levels of mathematical background.

• Scheduling: Due to the multidisciplinary nature of the students and courses, if the OPSE courses were scheduled only during the Spring or Fall semester, a significant number of students would not be able to take the OPSE courses as a free technical course elective. Consequently, OPSE 301 has to be offered during both the Spring and Fall semesters to accommodate student schedules and demand. Likewise, the class times for each 10 student section is chosen to avoid conflicts with other departments' core courses.
• Mathematical Background: Due to the multidisciplinary makeup of the students and their differing mathematical backgrounds, the OPSE 301 course does not heavily emphasize the study of optical science based on Maxwell's equations for electromagnetics. OPSE 301, which is predominantly taken by juniors and sophomores, stresses geometric optics and wave optics. Solutions of Maxwell's equations are introduced towards the end of the course in conjunction with birefringence and polarization. The de-emphasis of Maxwell's equations allows students of various majors to take the introductory OPSE 301 course without an extensive background in vector calculus and theoretical electromagnetics. However, the OPSE 402 applications course, which is predominantly taken by seniors, incorporates Maxwell's equations and their solutions from the outset.

Course 1: Optical Science & Engineering (OSPE 301) - Optics Principles

• Reference Texts: Fundamentals of Optics, Jenkins and White; Optics, Hecht and Zajac
• Prerequisites: Core courses Physics I, II, III, Calculus I -- completed by all sophomores.

This course, which provides a survey introduction to optics principles and their elementary applications, has both lecture and laboratory components. It is directed to junior level students in engineering and applied physics and has been offered Fall 96 and Spring 97. The prerequisites for the course are the sophomore level core-calculus and core-physics courses required of all engineering and science majors at NJIT. Students are assigned homework problems each week in addition to their lab reports, which constitute a majority of the students' grades. A brief outline of the course contents appears below.

• Lecture - Laboratory Safety and Precautions; EM spectrum; Speed of light and propagation; Sources of light: Lasers, Lamps, etc.; Reflection and Refraction -- Snell's law, brewster angle, total internal reflection, dispersion; Geometric Optics -- Mirrors, lenses, magnification, ray tracing techniques and software; Polarization; Birefringence; Interference -- interferometry and thin films; Diffraction -- gratings; Spectroscopy
• Laboratories
  1. Detection of light (a) Use photodiode and optical power meter to detect laser light. (b) Calibrate neutral density filters/ beamsplitter (c) determine linearity of photodiode.
  2. Reflection/refraction (a) study of Snell's law with different materials (b) total internal reflection (measure index of refraction) in a prism.
  3. Geometric Optics (a) build a simple microscope (b) expand and collimate a HeNe laser beam (c) spherical/ chromatic aberrations.
  4. Ray Tracing (a) Use ray tracing software to study simple combinations of lens, mirrors, and apertures. (b) design eye glasses to correct for astigmatism.
  5. Interferometry (a) use HeNe laser and bulk optics to build Michelson interferometer (b) adjust interferometer for circular and localized fringes, (c) measure absolute motion of mirror in one arm of interferometer.
  6. Diffraction (a) measure Franhoffer diffraction pattern through slit and compare to theory.
  7. Interference Gratings (a) measure diffraction pattern from a grating and compare to theory.
  8. Absorption (a) measure absorption of light by various concentrations of laser dye (b) experimentally verify Beers Law.
  9. Polarization (a) using a polarized light source, experimentally measure polarization properties of polarizing filters (b) l/4 wave plate (c) 1/2 wave plate.
  10. Polarization by reflection (a) measure ratio of s and p polarized light after transmission through a glass plate (b) experimentally determine Brewster's angle.
  11. Light Scattering (a) scattering and absorption of laser light from a suspension of particles.
  12. Spectrometers (a) measure spectral width of He-Ne laser as a function of spectrometer slit size (narrow source compared to instrument resolution) (b) measure spectra of fluorescent lamp.

The midterm and final exam have three parts: (1) questions related to homework problems (2) questions related to laboratory assignments and (3) lab-practical questions. The lab-practical questions require the students to examine an optical setup in the laboratory and answer questions concerning the setup. In one question, for example, the students were shown a laser, two polarizers, and a waveplate as illustrated in Fig. 2. By observing the polarization properties of the waveplate, the students were to experimentally determine if it were a 1/4 wave plate or a 1/2 wave plate based on their understanding of how waveplates function. Both the midterm and final exams are held in the optics laboratory to facilitate the lab-practical portion of the exams. With five optical tables available, several lab practical setups can be constructed.

Course 2: Optical Science & Engineering (OSPE 402) - Applications

• Reference Texts: Environmental Monitoring: Laser Diagnostics for Combustion Temperature and Species, A. Eckbreth; Optoelectronics: Introduction to Lasers and Applications, O'Shea, W. Callen, and Rhodes; Optical Electronics and Quantum Electronics, Yariv; Measurement systems: Application and Design, E.O. Doebelin.; Applied Optimal Control & Estimation, F Lewis; and recent faculty publications.
• Prerequisites: OPSE 301 or permission of Instructor.

The purpose of this course (offered Spring 97) is to apply the principles developed in OPSE 301 to selected problems in optoelectronics, sensors, and environmental engineering. OPSE 402, which is to be taken after OPSE 301, is directed to junior/senior level students in engineering and applied physics. The lecture and laboratory portions of the course focus on the different specialties of the associated faculty who design experiments and develop supporting lectures in their fields of expertise. Currently, there are four experiments covering optoelectronics, chemical reactions, environmental monitoring, and motion control/sensing.

Eventually, enough laboratories will be developed in order to give the students a choice in available experiments. Given the time constraints of a semester course, the students will eventually be asked to choose 5-6 of the available experiments. This option will allow students to conduct all of the experiments which are related to their majors as well as several more to give them a broad, multidisciplinary view of optics as an enabling technology. This multidisciplinary approach would allow the student flexibility in tailoring their choice of experiments to meet their academic interests and future career path goals.

• Lecture (current topics): Laboratory Safety and Precautions; Maxwell's equations: wave propagation; Electro-optics: the change of the refractive index as a function of applied electric; Absorption and transmission; Blackbody radiation; combustion; chemical reaction kinetics; Applications: Fiber Sensors
• Laboratories (current topics)
  1. Non-linear Optics: Electro-Optic Devices
     • Build and test a bulk electro-optic modulator.(4 weeks)
  2. Environmental Chemical Engineering
     • Batch Chemical Reactor with Laser Diagnostic
     • Flame Temperatures by Interferometry
  3. Sensor Applications
     • Motion Sensor - A sensor to measure the velocity of a liquid will be assembled and tested.

Course 3: Optical Science & Engineering 601 - Advanced Topics

OPSE 601 is designed to be a research/independent study course which allows the student to interact with the faculty in their research labs in small, focused groups. The prerequisite for the multidisciplinary course to be taken by new graduate students is OPSE 402. Of the available topics, the students must pick three projects to be completed during the semester. These projects are to be done in groups of 1 or 2 students in the respective faculty's research laboratories, which will enable individual attention and intensified training in laboratory techniques and research. The students will be required to do preliminary background reading/lectures in their topics of choice, set up the experiment, acquire and analyze data. At the end of 1 month, the student group will rotate to another project. Using this student rotation scheme, the number of students in the laboratories can be kept at a manageable level while the students have the opportunity to use modern optical research tools while conducting their experiments under close guidance of the faculty and associated members (e.g. graduate students, undergraduate assistants, post-docs) of the faculty member's research group. For the course's final exam, the student must present a 15 minute oral presentation on one of the month long projects. For many incoming graduate students, this oral presentation may be the first time that they are required to organize and publicly present their research. The topics are chosen based on their relevance to current research, ability to be completed in the allotted time, and student interest. The list of topics, which will be constantly updated as research progresses in the respective fields, are a mixture of recently completed and ongoing research. For those involving ongoing research, several students have made significant contributions towards research. Of the 6 students who enrolled in the first offering of OPSE 601, three will have portions of their work published in journal articles or presented at conferences.

• Possible topics: (* indicates a Fall 1996 offering)
  • *Nonlinear Properties of Materials: To teach experimental techniques to measure nonlinear, intensity-related refractive index changes (Kerr type).
  • *Deposition of Nano-size Semiconductor Clusters: To teach thin films deposition and characterization techniques.
  • *Optical Pulse Compression in Single-Mode Fibers
  • *Flame Emission as a Pollutant Monitor
  • Detection of Volatile Metal Species by PFF Spectroscopy
  • Proximity measurement using intensity modulation
  • Rotation measurement: To exposed the students to industrial sensor (gyro) engineering environments.
  • Fiber Optic Sensors: The students will be introduced to the experimental aspects of fiber optic technology, associated modulation effects, and optoelectronics interfacing.
  • *Time-Resolved Reflectivity: To introduce the students to ultrafast time-resolved reflectivity.
  • *Infrared Quenching of Persistent Photoconductivity in YBa2Cu3O6+,~ :To introduce the students to ongoing research in optical properties of superconductivity.

ACKNOWLEDGMENTS

This work is supported by the National Science Foundation, Combined Research/ Curriculum Development (CRCD) program.

II. Particle Technology Curriculum

Particle technology is concerned with the characterization, production, modification, flow, handling and utilization of granular solids or powders, both dry and in slurries. This technology spans a host of industries including chemical, agricultural, food products, pharmaceuticals, ceramics, mineral processing, advanced materials, munitions, aerospace, energy and pollution. As a consequence of the NSF/ CRCD grant, an interdisciplinary concentration of three new courses in particle technology [5], offered across the engineering disciplines, has been developed as one of the thrust areas of the Particle Technology Center at NJIT [11]. These courses cover material which is substantially absent in the established engineering curricula. In the next section, we address the need for education in particle technology, followed by a discussion of each of the three courses.

A. Why Particle Technology?

It is highly likely that most engineering graduates, in particular the graduates of mechanical, chemical, and civil engineering, will encounter products or processes involving granular or powder like materials at some stage of manufacturing. For example, E.I. du Pont de Nemours & Co. estimated that of the 3,000 products that it sold, 62% were powders, crystalline solids, granules, flakes, dispersions, slurries and pastes [3]. A further 18% of the products incorporate particles to impart key end-use properties. In the chemical process industries, a minimum estimate of 40% or $61 billion of the value added by the chemical industry is linked to particle technology. There are major problems encountered in handling and utilization of granular solids or powders because unlike pure fluids or gases for which reliable theories and scale up laws are available, there are few reliable techniques that allow for scale up and design of particle processing equipment. Moreover, although these materials often appear to flow like a liquid which may infer that particle mechanics can be handled by the methodologies which have been developed for analyzing the behavior of fluids, such attempts have often led to inadequate or even disastrous design of such equipment. For example, it was recently reported in Chemical Engineering Progress that "Plants handling solids anywhere in the main process train perform more poorly than those processing only liquids and gases. Recently built plants perform no better than those built in the 1960's. Average plants with solid feedstock operate at only 50% of design capacity. One-fifth fail to attain more than 20%, and although startup time for a plant processing raw solids is usually estimated to take 3.5 times as long as liquid/gas processing plants, the actual startup times are 6 times longer!" [3]. In summary, the chances of our graduating engineers encountering problems related to particle technology in their future careers are very high. Therefore it is important for them to be exposed to this subject during their education. It is anticipated that the three courses developed in particle technology at NJIT will help in overcoming the current deficiency in the engineering curriculum in this vital area.

A major challenge of the NSF-CRCD project is to present the basic concepts, industrial practice and new research in particle technology without overwhelming the students, yet exposing him/her to a new set of tools required for problem solving in this field. This will be done through classroom instruction, physical experiments as well as computer simulated experiments. Our syllabus, which is very ambitious, makes the task of delivery of education very difficult and thus creates a challenge for which we are preparing ourselves and our graduate students, who will, in turn, help the students in the physical and computer laboratories. The difficulties arise due to the fact that we plan to employ equipment and software which are not routinely used in the current engineering curriculum, such as state-of-the-art instrumentation for characterization, mixing and flow property measurement, as well as image analysis and video animation systems. We must also teach the students the use of associated software. The current curriculum does not have the infrastructure to accommodate this, and our challenge is to develop an easy to use set of instructions, and to train graduate students who can be available to consult with the students.

B. Summary of Accomplishments

• Formation of an advisory board with particle technology experts from industry, academia and research laboratories. It comprises representatives from 12 industrial companies, 5 universities and a US National Laboratory. Board meetings are held every March, starting from March 1995.
• Development and running of the undergraduate lecture course ("Introduction to Particle Technology: Research Fundamentals and Applications"), during the Fall '95 semester by Dr. I. Fischer (Mechanical Engineering), for which approximately 20 students, both undergraduates and graduates, were enrolled.
• The development and running of an advanced graduate course* in Summer '95 by Dr. J. Luke (Mathematics Dept.) covering low Reynolds number hydrodynamics, sedimentation and flow around suspensions. Some of the materials developed were used in the graduate lecture course run during Spring '96.
• Running of a special graduate course* during the Fall '95 was taught by Dr. R. Dave, entitled "Image Analysis Applications in Particle Technology," for which eight students were registered.
• Offering of the graduate course "Current Research in Particle Technology" taught by Dr. Dave during the Spring '96. Nine students took this course for credit, and one student audited the course. Several external guest lecturers gave presentations during the semester. As a part of this course, a special one day workshop was organized on March 30, 1996.
• Completion of renovations and expansion of the Particle Technology Center Instructional Laboratory (housed in the Mechanical Engineering Dept.) for the laboratory course ("Experiments and Simulations in Particle Technology") offered in the Fall 1996 semester by Dr. R. Dave, were completed.

C. Course Descriptions

The concentration consists of three principal courses: (1) "Introduction to Particle Technology", designed for upper-level undergraduates and first-year graduate students; (2) "Current Research in Particle Technology", intended for graduate students; and (3) "Experiments and Simulations in Particle Technology" which is intended for upper-level undergraduates and first-year graduate students.

Course 1: Introduction to Particle Technology

During the Fall 1995 semester, Dr. Ian S. Fischer conducted the undergraduate lecture course "Introduction to Particle Technology" for twenty students majoring in mechanical and chemical engineering. Several references books were used [4,10,12] for the syllabus material described below.

• Particle Characterization
  Determination of the shape and size of particles, sampling, shape factors and fractal dimensions for irregular shapes, Stokes' Law /sedimentation, physics of Coulter counter, radiation scattering methods, optical size-measurement systems
• Coulomb Materials
  Mechanics of Coulomb materials, yield criterion of a granular material, active and passive Rankine states, unconfined yield stress, angle of repose and internal friction angle, Coulomb's method of wedges, Janssen's equation for stresses on walls of bins and hoppers, Walter's switch stress
• Hopper Design
  Core flow versus mass flow, Jenike shear cell and yield locus, material flow function and flow factor to size hopper outlet and slope, consolidation and compaction effects during loading and unloading hoppers
• Conveyor Belts
  Design based on handbook by manufacturer trade associations, conveyability characteristics (i.e., repose angle, angle of surcharge, flowability, density, dustiness, wetness, abrasiveness, corrosiveness and temperature), power requirements, belt tension, and idler spacing
• Solid-Gas Separation
  Aero-mechanical separators, wet scrubbers, electrostatic precipitators and filters, pressure drop, flow rate, grade efficiency and cut size to characterize devices, cyclone dryseparation
• Gas Fluidization
  Purpose of fluidized bed, aeratable, sand-like, cohesive and spoutable powders, bed pressure drop, minimum fluidization velocity, slugging, bed expansion, entrainment of solids in exhaust and heat transfer
• Suspensions and Sedimentation
  Faxen's law, the angular velocity of a suspended particle, "effective fluid" model of a suspension, effective velocity, Einstein viscosity, super-dilute theory
• Slurries and Suspensions
  Forces on a particle in a fluid, terminal settling velocity, drag coefficient, Archimedes' number, homogeneous suspensions, rheological behavior, measurement devices, Newtonian, power-law, Bingham plastic and Casson constitutive equations, Arrhenius equation, temperature-reference method, laminar and turbulent flows of suspensions in pipes, mixing of powder in agitated tanks, saltation, Durrand's correlation, vessel agitation, critical speed of an a~itation impeller
• Particle Size Enlargement
  Applications in industry, methods, mechanics of agglomeration, inclined-disk agglomerators and drum granulators
• Particle Size Reduction
  Crushing and grinding and factors, forces in size reduction, Rittinger, Kick, Bond and Holmes methods for energy requirements, mathematics of predicting product size distribution, description of crushing and grinding machines in industry, example of size distribution in hammer mill
• Collision Mechanics (lecture conducted by R. Dave)
  Coefficient of restitution, planar impact of spheres, Mindlin's study of the oblique contact of two frictional spheres (non-sliding contact and micro-slip and non-slip regions), normal collision of elastic spheres, collision of frictional elastic spheres and the collision of inelastic spheres (plastic deformation), Johnson's model for coefficient of restitution

Course 2: Current Research in Particle Technology

This course, intended for graduate students, is theoretical in nature and includes mathematical modeling and computer simulations capable of describing bulk behavior of particulate flows from the properties of the material. Also incorporated are recent research developments in the field not yet appearing in standard textbooks. The course was given for the first time in the Spring 1996 semester by Dr. Dave and again in the Spring 1997 by Dr. Rosato. In the Spring 1996, the syllabus brought together a broad range of topics in an attempt to give students an overview in the event that they had not taken the introductory course (described above). A number of presentations were given by guest lecturers with expertise in specifics topics. Upon completion of the course, it was decided to focus the syllabus within the expertise of the instructor while preserving some of the introductory overview material, and to continue to include guest speakers on important topics. Below is a brief outline of the course material for each semester.

• Spring 1996: General overview and introduction, collision mechanics, computer simulations for dry granular flows and computing transport properties, dynamics of sedimentation, suspension viscosity, guest lectures (follows)
  • Dr. R. K. Singh: Dept. of Materials Science and Engineering, University of Florida at Gainesville (1/24/96), "Transient Thermal and Chemical Beam Processing of Materials"
  • Dr. A. A. Boateng: Solite Corporation, Richmond, VA (2/5/96), "Rotary Kiln Transport Phenomena & Transport Processes"
  • Dr. P. Singh: Materials Process Engineering, Los Alamos National Laboratory (3/18/96), "Processing of Complex Fluids".
  • Dr. L. S. Fan: Chemical Engineering Department, Ohio State University (3/30/96), "Fluidization Engineering".
  • Dr. O. R. Walton: Lawrence Livermore National Laboratory (3/30/96), "Discrete Element Simulations of Granular Flows".
  • Dr. C. Wassgren: Mechanical Engineering Department, California Institute of Technology (4/4/96), "Experiments and Simulations of Vibrated Beds".
  • Dr. C. Tahir: Energy International, Inc. (4l8/96), "LDV Measurements of SinglePhase and Dilute Solid-Liquid Flows in a Centrifugal Slurry Pump"
• Spring 1997: General overview and introduction, one-dimensional linear and nonlinear mass / spring / dashpot collision models, heuristics approach to wave propagation in granular materials, three-parameter hard sphere model of Walton and recent related experimental measurements, Walton and Braun soft sphere normal force approximation, bouncing "superball" problem, computation of transport quantities (pressure and diffusion tensors), simulations / experiments on the behavior of vibrating granular beds, statics and kinematics of granular materials [10], particle classification (Dr. K. Leschonski, Univ. of Clasuthal), nuclear magnetic resonance imaging of highly energetic flows (Dr. A. Caprihan, Lovelace Respiratory Research Institute, Albuquerque, NM), dry filtration (Dr. R. Pfeffer, NJIT).

Course 3: Experiments and Simulations in Particle Technology

As part of the NSF/CRCD grant, a new laboratory was developed During Fall 1996, the first offering of this course was given by Dr. Dave. Since the laboratory at this time was still in the development state, a select number of classical experiments and related research experiments were included. In the future, several experiments will be integrated into core undergraduate laboratory courses in Mechanical and Chemical Engineering departments. It is anticipated that laboratory development will be completed in Fall 1997 when the course will be offered again.

Available Equipment: Jenike flow factor tester, Jenike compressibility tester, Jenike quality control tester, Patterson-Kelley BlendMaster Blender/Mixer, Malvern Particle Size Analyzer (Mastersizer X), Paul Abbe ball mill, Octagon 2000 vibrated siever, fluidized bed, flexible hopper, angle of repose measurement devices, Kodak EktaPro 1000 high-speed video system, particle collision properties measurement apparatus, B&K vibration exciter system, nonintrusive tracking system, dilatometer, rotating fluidized bed reactor, SEM, X-Ray diffraction, EDX (in the NJIT Geoenvironmental lab), 2 SGI Indigo graphics workstations with Galileo video board and Cosmo compress boards, Sony frame accurate SVHS VCR and 30" monitor.

• Angle of Repose
  The students are asked to measure the angle of repose of a variety of granular materials using four different classical methods (fixed height table, fixed base cone, tilting table and rotating cylinder). A digital camera and image analysis are used to measure the angles of repose from the four methods and results are compared.
  
• Particle Size Analysis Using Sieves
  Sieving, one of the simplest, oldest and inexpensive methods of determining particle size distribution and widely used in industry [8], is effective for sizes down to about 38 microns. The sieving apparatus used in our experiments is an Octagon 2000 Vibrated Siever, with a set of sieves ranging from 250 microns (mesh # 60) to 4.0 mm (mesh # 5). By stacking a set of sieves with the sample placed in the top sieve, one could obtain a size distribution curve by weighing the residuals at each sieve and the cumulative distribution. The students analyzed samples of coarse sand to obtain these results. For the tested samples, the students also collected data to study the sieving rate.
  
• Particle Size Analysis Using Laser Diffraction Technique
  In our laboratory, we have a Malvem Mastersizer X Laser Diffraction particle size analyzer. The students performed size analysis of samples obtained through a grinding experiment. The samples analyzed had a size range from a few microns to about 100 microns. During the course of the experiment, the students learnt about sample collection, preparation, and the use of the Mastersizer. The most basic task of sample collection was perhaps the most difficult, and it was realized that a better sampling scheme would be required. The Mastersizer software allows for selecting different scattering theories and the refractive index models. Students utilized both fraunhofer and Mie scattering theories, and changed the model used for the refractive index. For each case the results such as the "mode" (of the size distribution) and the "residual" (of the fit of measured and computed scattering data for all the detectors) were recorded.
  
• Size Reduction/Grinding with a Ball Mill
  For the basic ball mill experiment, we have used a ball mill (Paul Abbe Ball Mill) with a ceramic cylindrical jar and cylindrical Burundum Alumina as the grinding media. The students were asked to perform a simple grinding experiment to study the rate of change in the particle size distribution as a function of time. A challenge in this experiment was to find a suitable test material capable of demonstrating the main features of the grinding process within a 2-3 hour lab period. For the sake of demonstration, soft gravel-like material of size 250 microns to about 4 mm was utilized.
  
• Material Testing by Jenike Shear Cell for Design of Mass Flow Hoppers
  The purpose of this experiment is to calculate parameters of a mass flow hopper for a given test material . The main issue in hopper design is the material testing procedure that provides the information about flowability and cohesiveness of the material so that one can decide on the hopper slope and minimum outlet size. There are many different methods to test the flowability of the material [7], although the Jenike method [6] (which yields the Jenike yield locus) is still considered the most reliable and is perhaps the most widely used technique in industry. There is a detailed standard procedure for using the Jenike apparatus, since the variability and the scatter in the test data is found to be very wide if careful testing is not performed [13]. Each yield locus is formed by plotting the normal stress (shear weight) verses the pro-rated shear stress. Students tested materials such as flour, powdered sugar, and corn starch. Highly cohesive materials (i.e., corn starch) pose difficulties in obtaining reliable results. It was found that the test apparatus was not very user friendly, and the task of complete testing is tedious and would require 5 to 6 hours. In the future, we plan to use a flexible hopper to verify the results obtained using the Jenike device to design a mass flow hopper.
  
• Study of Rise of a Single Large Sphere in a Vibrated Granular Bed
  Size segregation is often an undesirable outcome of handling and/or processing operations of bulk solids. In general, a large ball placed at the bottom of a vibrated bed will rise to the surface [9]. In the laboratory sessions, the students are asked to examine various behavioral regimes of the vibrated bed and make observations of the rise time of the large particle at different operating conditions.
  
• Dilatometer Measurement of the Minimum Sintering Temperature of Fluidized Solids
  Fluidized beds are used in a variety of industrial processes including the catalytic cracking of petroleum to make gasoline, aviation fuel and home heating oil, the conversion of mineral ores into useful products, and the coating and granulation of pharmaceuticals. Many of these processes operate at high temperatures, which cause softening and/or partial melting (sintering) of the solids' surfaces, thereby requiring higher gas velocities to keep the bed in the fluidized state. The purpose of this lab is to measure the minimum sintering temperature T_s (temperature at which thermally induced surface softening and sintering begins), an intrinsic property of the solid particle surface. A relatively simple procedure to estimate T_s (developed by Dr. Robert Pfeffer, his colleagues, and students) makes use of constant rate dilatometry [1, 2, 14] obtain the elongation-contraction versus temperature curve for a porous rod composed of the granular material in question. In the experiment, a Theta Industries - Econo I dilatometer is used to heat a small sample of powder (~ 1.2 grams) at a constant rate (maximum is 15C/minute) to temperatures as high as 1600C. Following a classroom lecture, students were given a known alumina-based catalyst sample . They then set up the experiment programmed the dilatometer to operate overnight at a constant heating rate in a Nitrogen atmosphere. Results were analyzed the next day to determine T_s.
  
• Particle Sedimentation
  The falling ball viscometer is the first in a sequence of experiments concerning suspensions and sedimentation. The apparatus consists of a glass cylinder (100 cm long x 10 cm diameter) containing a viscous fluid (Ucon fluid 50-HB-35201). Small numbers of particles placed in the fluid at the top of the cylinder may be observed as they sediment along the axis of the cylinder. Student receive instruction on the basic theory of sedimentation at low Reynolds number and its application to size segregation and characterization. Using the manufacture's statement of the physical properties of the fluid, a collection of particles, a balance, a thermocouple based thermometer, a meter stick and a stop watch, students are asked to investigate some of the physical properties of the device. Issues investigated include particle-wall and particle-particle interactions, inertial effects and thermal effects. A given group of students is asked to focus on a single issue. Particular emphasis is placed on having student explain variability in observations. Reports will be kept on file and future students will be asked to analyze there reports and reconcile their results with those of groups in previous years.
  
• Other Planned Experiments
  Blending and mixing, Fluidized bed, Rotating fluidized bed, Core Flow / Mass flow hoppers, Measurement of particle collision properties, Non-intrusive tracking in granular flows, Dry particle coating, Simulation and visualization of granular flows

ACKNOWLEDGMENTS

EEC9420597 (CRCD) and EEC-9354671, as well as Exxon Teaching Aids grants. We also appreciate help from all the students who participated in the laboratory course. Thank are also due to Mark Bumiller of Malvem Instruments for presenting a lecture to the students on particle size analyzers. We are also very grateful for useful discussions with many advisory board members, in particular, Karl Jacob of Dow Midland. Lastly, we deeply appreciate the time Rachel Anderson (Dow Midland) spent with us on the Jenike test procedure and for providing very useful background

1 Manufactured by Union Carbide Corp.

REFERENCES

1. Compo, P., Tardos, G. I., Mazzone, D., Pfeffer, R., "Minimum Sintering Temperatures of Fluidizable Particles," Particle Characterization, Vol. 1,p. 171, 1984.
2. Compo, P., Tardos, G. I., Pfeffer, R., "Minimum Sintering Temperatures and Defluidization Characteristics of Agglomerating Particles," Powder Technology, Vol. 51, pp. 85-101, 1987.
3. Ennis, B., Green, J., Davies, R., "Particle Technology: The Legacy of Neglect in the U.S.," Chemical Engineering Progress 32, April 1994.
4. Fan, L-S., Zhu, C., Principles of Gas-Solid Flows, Cambridge University Press, Cambridge, UK, to appear July 1997.
5. Fischer, I. S., Dave, R. N., Luke, J., Rosato, A. D., Pfeffer, R., "Particle Technology in the Engineering Curriculum at NJIT," Proceedings of 1996 ASEE Annual Conference, Session 1626, Washington D.C., June 23-27, 1996.
6. Jenike, A., W., Storage and Flow of Solids, Bulletin No. 123 of the Utah Engineering Station, Salt Lake City, Utah, March 1970
7. Kamath, S., Puri, V., M., Manbeck, H. B., and Hogg, R., "Measurement of Flow Properties of Bulk Solids Using Four testers," l991 International Winter Meeting of the American Society of Agricultural Engineers, Paper no. 91-4517, 1991.
8. Leschonski, K., "Sieve Analyses, the Cinderella of Particle Size Analysis Method" Powder Tech.,24, pp. 115-124, 1979.
9. Loic, V., Rosato, A. D. and Dave, R. N., "Rise Regimes of a Large Sphere in Vibrated Bulk Solids", Phys. Rev. Lett., Feb. 17, 1997.
10. Nedderman, R. M., Statics and Kinematics of Granular Materials, Cambridge University Press, Cambridge, UK, 1992.
11. Particle Technology Center at NJIT, http://www-ec.njit.edu/ec_info/image2/ptc
12. Rhodes, M., Principles of Powder Technology, John Wiley, Chichester, UK, 1990.
13. Standard Shear Testing Technique for Particulate Solids Using the Jenike Shear Cell, A Report of the EFCE (The Institution of Chemical Engineers: Europian Federation of Chemical Engineering) Working Party on the Mechanics of Particulate Solids, 1989.
14. Tardos, G. I., Pfeffer, R., "Chemical Reaction Induced Agglomeration and Defluidization of Fluidized Beds," Powder Technology, Vol. 85, p. 29, 1995.

* These courses, offered as special topics, are in addition to the three courses developed under the current grant and are intended to supplement the curriculum and instructional laboratory. up

Back to Table of Contents