exp-enginerring properties.ppt
- 1. University Institute of Agricultural Sciences Dr. Ambika Name of Topic: Determination of engineering properties (shape and size, bulk density and porosity of biomaterials). Chapter 3 Lecture - 7 DISCOVER . LEARN . EMPOWER
- 2. 2 Objectives To strengthen the understanding of basics of green house technology To focus on Green house equipments Course Outcome To acquaint students with principles of green house technology To provide basic knowledge of green house equipments
- 3. Experiment 7. Determination of engineering properties (shape and size, bulk density and porosity of biomaterials). 1. Grain size and shape Grain size and shape (length-width ratio) is a very stable varietal property that can be used to measure the varietal purity of a sample. Comparing the length- width ratio of the sample with a published ratio for the variety will give an indication of varietal purity of the grain sample. A significant deviation means that the sample is impure – that is, it is either a different variety or a mixture of varieties.
- 4. • Obtain a random sample from the seed batch. • Collect 20 grains at random from this sample of seed. • Use a Vernier caliper or photographic enlarger to measure the dimensions of each grain. 2. 1000 grain weight • Each variety has a published weight for 1000 grains. If the 1000-grain weight calculated from the sample departs from this, it may be an indication that the sample contains a mixture of varieties. • Select a random sample from the seed batch • Count 1,000 whole grains from the sample. Weigh the 1,000 grains.
- 5. 3. Bulk Density Bulk density was determined by liquid displacement method. Fifty ml distilled water was taken in the measuring cylinder and volume was noted. Fifty g seeds were weighed accurately and transferred to the cylinder. Increase in volume of water was recorded to calculate bulk density and expressed as g/cc. 4. Hydration Capacity Seeds weighing 10 g were counted and transferred to a measuring cylinder. To this 30 ml water was added and cylinder was covered with aluminum foil and left overnight at room temperature. Next day, seeds were drained, superfluous water was removed with filter paper and swollen seeds were reweighed. Increase in weight x100 5. Hydration capacity (%) = Weight (g) of seeds Increase in weight 6. Hydration capacity (per seed) = Number of seeds
- 6. 7. Hydration index Hydration index was calculated using the following formula: Hydration capacity per seed Hydration index = Weight (g) of one seed
- 7. 8. Swelling capacity Seeds weighing 10 gm were counted and their volume was noted and soaked overnight. The volume of soaked seeds were noted in graduated cylinder. Increase in volume x100 Swelling capacity (%) = Weight (g) of seeds 9. Swelling capacity (per seed) = Volume after soaking-Volume before soaking Number of seeds 10. Swelling index Swelling index was calculated using the formula: Swelling capacity per seed Swelling index = Seed volume (ml)
- 8. • Porosity: (inter granular space) : Total porosity is defined as the fraction of the bulk rock volume V that is not occupied by solid matter. If the volume of solids is denoted by Vs, and the pore volume as Vp = V - Vs, we can write the porosity as: ϕ= V – VS/V = VP/V