Lecture 4 – Physical AttributesLecture 4: Physical Attributes Chpt 2, Pages 11-20Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9HW#4 Assignment Due 1/25HW#4 Part Assignment Due 1/2501/14/19 BAE2023 Physical Properties of Biological Materials Lecture 41Lecture 4 – Physical Attributes01/14/19 2Lecture 4: Physical AttributesChpt 2, Pages 11-20•For grain, seeds, fruits, vegetables–Size described by 3 dimensions•Major diameter: longest dimension of the max projected area (fat part)•Intermediate diameter: min. diameter on the max projected area, assumed to be equal to the longest diameter of the min projected area (thickness)•Minor diameter: shortest dimension of the minimum projected area (skinny part)–May be referred to differently in industry•Usually called length, width, and depthBAE2023 Physical Properties of Biological Materials Lecture 401/14/19 3•Shape: used to describe unprocessed foods–Example: carrots = cones•Style: used to describe processed foods–Example: carrot coins, french cut beans, apple wedges, banana chips•Shape: use geometric solids…sphere,truncated cone (see appendix C)Lecture 4: Physical AttributesChpt 2, Pages 11-20BAE2023 Physical Properties of Biological Materials Lecture 401/14/19 4•Sphericity:–Ratio of volume of triaxial ellipsoid to a circumscribed sphere (show correction in book for 2a, 2b, 2c, page 13 and pg 14 example)–Blueberry exampleLecture 4: Physical AttributesChpt 2, Pages 11-20BAE2023 Physical Properties of Biological Materials Lecture 401/14/19 5•Sphericity, Sc:–Aspect ratio, Ra = (b/a)*100–Ra >50%...tends to slide–Sc >50%...tends to roll–Both > 50%, will tend to roll with some slidingLecture 4: Physical AttributesChpt 2, Pages 11-20BAE2023 Physical Properties of Biological Materials Lecture 401/14/19 6•Volume –Volume determined by liquid or gas displacement–Pycnometers or graduated burettes–Weight of fluid displaced by solids divided by the density of the fluid = volume of the solid particles•Buoyant force of water on object, page 16, 2.3–Platform balance•Optical methodLecture 4: Physical AttributesChpt 2, Pages 11-20BAE2023 Physical Properties of Biological Materials Lecture 401/14/19 7•Volume–Volume determined by gas displacement–Page 17 Fig.2.2–Gas penetrates grains and seeds•Coat with waxLecture 4: Physical AttributesChpt 2, Pages 11-20BAE2023 Physical Properties of Biological Materials Lecture 401/14/19 8•Volume–Estimation through calculation–Use Appendix C for equations of similar geometries–Error determination, %:[(Your calculation – test value)/(test value)]*100Example: calculated volume using equation…48.7 mm3Gas pyncnometer measure 50.1 mm3Lecture 4: Physical AttributesChpt 2, Pages 11-20BAE2023 Physical Properties of Biological Materials Lecture 401/14/19 9•Surface Area–Peel–Coating and peeling–Bread loaf estimation example•Estimate Surface Area–Similarity to geometric solids–Appendix C (not A!!!)•Example 2.3 page 19Lecture 4: Physical AttributesChpt 2, Pages 11-20BAE2023 Physical Properties of Biological Materials Lecture 401/14/19 10HW#4 AssignmentDue 1/25•Problem 1: –A) Calculate the sphericity of a blueberry, a Red Haven peach, and a Norchip potato. –B) Which one is more spherical?•Problem 2:–Calculate the volume of a Bart 46 Wheat kernel•Reference data –What is the percentage error when compared to the volume determined by testing?•Problem 3: –Using a piece of fruit or vegetable of your choice, and example 2.3 in Chpt 2, determine the volume and surface area. BAE2023 Physical Properties of Biological Materials Lecture 401/14/19 11HW#4 Part AssignmentDue 1/25•Problem 4: #2.6 in book•Problem 5:•#2.12 in bookBAE2023 Physical Properties of Biological Materials Lecture
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