Preparation of anhydrite from eggshell via pyrolysis

Calcium sulfate dihydrate (CaSO4·2H2O) was prepared from the chemical reaction between calcium carbonate from duck eggshell and sulfuric acid at 25°C. The CaSO4·2H2O was dried in an oven at 110°C and transformed into calcium sulfate hemihydrate or plaster of Paris (CaSO4·0.5H2O). The CaSO4·0.5H2O was calcined at 700, 800 and 900°C and transformed into anhydrite or anhydrous calcium sulfate (CaSO4). The raw material used in this research was the duck eggshell, the waste eggshell generated from food processing industries. The obtained anhydrous calcium sulfate or anhydrite has true density, color, specific surface area, pore diameter and particle size equal to 2.95 g/cm3, white powder, 3.57 m2/g, 96.98 Å and 3.983 μm, respectively. In addition, other characteristics, microstructures, phase transformation and physical properties of raw materials and calcium sulfates were investigated and reported here using X-ray fluorescencemeter, Fourier transform infrared spectrometer, differential thermal analyzer, thermogravimetric analysis, scanning electron microscope, X-ray diffractometer, pycnometer method and Brunauer-Emmett-Teller.

Cryopreservation of Tomato Pollen

We have developed a method for cryopreserving Lycopersicon esculentum pollen to facilitate the timing of crosses and for long-term germplasm conservation. Gelatin capsules containing pollen were wrapped in tissue paper and placed in air-tight glass tubes with anhydrous calcium sulfate desiccant. Tubes containing pollen were stored at –80C. In one experiment, we stored the pollen of LA359 and T5 at –80C for 37 days. Pollen predesiccated overnight at 4C then stored at –80C, pollen put in a tube with desiccant then immediately stored at –80C, and fresh pollen were compared by pollinating 10 flowers of LA359 with each of the six pollen treatments and counting the number of seed per fruit. Average seed counts ranged from 127 for fresh, T5 pollen to 172 for predesiccated LA359 pollen. In another experiment, cryopreserved pollen of UC82B and VFNT Cherry was given from 0 to 6 cycles of freezing and thawing. Ten flowers of LA359 were pollinated with each of the 12 treatments. Average seed counts ranged from 125 to 152. The data from both experiments suggest that cryopreservation of tomato pollen to facilitate efficient plant breeding is feasible.