Testing a leaf for starch is a common experiment in biology classrooms, as it allows students to understand the process of photosynthesis and how plants use energy. In this lab report, we will outline the materials and methods used, describe the results of the experiment, and discuss the implications of these results.
Materials:
- Fresh leaf from a green plant
- Iodine solution
- Beaker
- Test tube
- Glass stirring rod
- Dropper
- Paper towels
Methods:
- Obtain a fresh leaf from a green plant and gently wash it with water to remove any dirt or debris.
- Fill a beaker with water and add a few drops of iodine solution.
- Use a dropper to place a small drop of the iodine solution onto the leaf.
- Observe the color of the iodine on the leaf. If the leaf contains starch, the iodine will turn blue or black. If the leaf does not contain starch, the iodine will remain yellow or orange.
- Repeat the process with a few additional drops of iodine to confirm the results.
- If necessary, use a glass stirring rod to scrape a small piece of tissue from the leaf and place it in a test tube. Add a few drops of iodine solution to the test tube and observe the color change.
Results:
In our experiment, we found that the iodine turned blue or black when applied to the leaf, indicating the presence of starch. When a small piece of tissue was placed in a test tube and mixed with iodine solution, the solution also turned blue or black. These results suggest that the leaf we tested contains starch.
Discussion:
Starch is a complex carbohydrate that plants use to store energy. It is produced during photosynthesis, when the plant uses energy from sunlight to convert carbon dioxide and water into glucose. The glucose is then converted into starch and stored in the plant's tissues, such as leaves, stems, and roots.
The presence of starch in the leaf we tested confirms that the plant is able to carry out photosynthesis and produce glucose. This is important for the plant's survival, as it allows the plant to store energy for times when sunlight is not available, such as at night or during periods of low light intensity.
Overall, testing a leaf for starch is a simple and effective way to understand the process of photosynthesis and the role of starch in plant metabolism. It also helps students learn how to use scientific equipment and follow experimental procedures, which are important skills for any aspiring scientist.
Piper Alpha: The Disaster in Detail
A gas treatment plant was retrofitted and gas export started in December 1978. While bespoke communications can have some benefits, minimum standards were not set or met. How many overrides are in place today? When did I last test each part of my emergency response in practice? Was the procedure adequate? Emergency response — evacuation; 7. Handover On Piper Alpha, communications between departments, between shifts, and between crews was personal, informal and tailored to the job. But a regulations-bound system falls down because practices not covered by regulations are simply not addressed. Sandhaven, which was the standby vessel for the nearby Santa Fe 135, were also killed in attempts to pick up survivors in the Sandhaven's Fast Rescue Boat. It appears that the operators were not aware of another suspended permit.
It is not known how effective the deluge would have been had it deployed as the nozzles often blocked with scale and the fire-water pipework on Piper Alpha was undergoing phased replacement. Such regulations have their uses, provided all eventualities have been considered. People become complacent when they are encouraged to think that safety can be ensured by rules enforced by inspectors: it is impossible to cover all eventualities in a set of general rules. When fire broke out on Piper Alpha, the only way to activate the fire-fighting system was to start the pumps locally. The fires from the wells and the oil and gas lines all of which ruptured, one by one had produced flames with a height of about 200 metres and a peak rate of energy consumption of ~100 gigawatts, three times the rate of UK total energy consumption.
Shortly afterwards, gas alarms activated, the first-stage gas compressors tripped and the flare was observed to be much larger than usual. The oil from Tartan to Claymore joined oil from Piper Alpha at a Y junction before flowing onwards to Flotta. It was assumed that, whatever happened, evacuation would be at least substantially by helicopter. The Cullen inquiry uncovered not only what probably happened on the terrible night of 06 July 1988, but also the complex path leading up to it, the early warnings and missed opportunities that might have prevented a tragedy in which 167 people lost their lives. Summary The investigation into the Piper Alpha disaster has much to teach us thirty years on. The largest part of the platform followed it.
After removal of water and hydrogen sulphide in molecular sieves, gas was compressed and then cooled by expansion. The lessons to be learned are applicable far beyond the offshore oil industry, across all hazardous industries, and every bit as relevant today. Could more rapid shutdown at the other platforms, and in particular blowdown or depressurization of the inter-platform gas lines have averted disaster? Management of change design issues ; 2. Personal safety over process safety fire water pumps on manual start to protect divers ; 3. Figure 2: PFD Condensate pumps and safety relief valves Permit to work and isolation for maintenance The night shift operators were aware that condensate injection pump A was out of commission for maintenance and also that maintenance had not yet started: the maintenance and associated work permits had been suspended overnight. Oil production started in 1976 with about 250,000 barrels 40,000m 3 of oil per day, increasing to 300,000 barrels 48,000m 3. The publication was launched in 1974 in response to the disastrous explosion at Flixborough, in order for the process industries to share information about accidents.
Retrieved 3 February 2017. Witnesses reported a second flash and bang as a huge fireball roared into the night sky. By the early morning of 07 July 1988, three-quarters of the original topsides, together with significant sections of the jacket, had been destroyed and lay in a tangled mass on the sea bed 140 metres below. Twenty minutes later, at about 22. Retrieved 25 July 2009. It took over three weeks for the fires to be extinguished.
The subset of lessons described here illustrate the widespread system failures that led to the Piper Alpha tragedy. Although not intended primarily as a fire-fighting vessel, Tharos had significant fire-fighting capabilities. Why did it have such disastrous consequences? According to witnesses, if the newcomer had worked offshore before, then training was brief to the point of non-existent. Phase 1 mode where excess gas was flared and Phase 2 mode where gas was exported. The recommendations led Most significant of these recommendations was that operators were required to present a In 2013, on the 25th anniversary of the disaster, the video Remembering Piper - The Night That Changed Our Lives was released by Step Change in Safety.
The suspended work permits were not displayed in the control room but in the safety office. However, because the platform was originally built for oil, the firewalls were designed to resist fire rather than withstand explosions. When did I last carry out a permit to work audit to see how the system actually works in practice? In 4 cases, the cause of death could not be established, and 30 bodies were never recovered. Retrieved 3 February 2017. Retrieved 29 March 2022. It could be argued it was a good thing that the Cullen Inquiry left open the exact cause of the disaster.
