全國中小學科展

那米比亞

The Solution to Global Water Pollution?

The waters of the Benguela, the Atlantic Ocean off South Western African shorelines, are amongst the most productive in the world, supporting prolific marine life. However despite the abundance of animals, survival in this marine ecosystem is not always easy. Oxygen-deficient bottom water, often containing toxic hydrogen sulphide, is a feature of the northern Benguela coastal upwelling system. Here, superfluous cells from excess phytoplankton production, decay and sink to the bottom to form the oozy diatomaceous mud belt sediment off the Namibian coastline. Within this diatomaceous mud further intensified decay takes place to form toxic hydrogen sulphide in the sediment. Sporadically large amounts of the hydrogen sulphide are released into the water column, causing the deadly annual "sulphur" events, as they are locally known in Namibia, to take place. Sulphur eruptions result in the deaths of thousands of marine animals. This marine system off the Namibian coast, with its harsh natural conditions of hydrogen sulphide and low oxygen, is similar to an ecosystem suffering intensive marine pollution. These natural conditions of the Benguelan waters are closely related to the conditions of many coastal areas suffering from the global marine pollution problem, created by man all over the world, through the discharge and disposal of wastes, such as nitrate fertilisers, sewage and biological decay material. A specialsed group of bacteria known as sulphur bacteria occur within the sulphidic conditions of the sediments. Sulphur bacteria actually use some of the produced toxic hydrogen sulphide in the sediments, converting it to harmless elemental sulphur micro granules in their cytoplasm. Where no other life occurs, due to the harsh conditions unfriendly to most marine lifr, sulphur bacteria thrive. Sulphur bacteria control and decrease the amount of hydrogen sulphide, which goes from the sediment into the water, through their complex metabolic systems. The biggest and most effective sulphur bacteria, only found off the Namibian coast, were dubbed Thiomargarita namibiensis. Thio means sulphur and namibiensis refers to its occurrence in Namibia. This giant sulphur-eating microbe is the earth's biggest known bacterium, visible to the naked eye. I conclude with a personal hypothesis to suggest a solution to global water pollution by utilising this magnificent bacterium. Through bacterial cultivation and processing Thiomargarita namibiensis could be employed in tacking extent of global marine pollution. The bacteria use toxic hydrogen sulphide as "fuel" for their metabolism and nitrate as an oxidizing agent, to produce harmless sulphur granules. This explains the bacteria's effectivity in removing nitrate and hydrogen sulphide wastes, the forms most biological wastes eventually occur in, from the water. This spectacular process, as it occurs within these magnificent "sulphur pearl strings", could be the sensational answer to the regeneration of polluted marine waters on a worldwide scale. This absolutely natural treatment of the water would not bear any harmful consequences such as those artificial treatment leaves behind. Sewage treatment or denitrifying treatments applied by man on polluted water leaves chemical discharge and damage to affected ecosystems. Especially Thiomargarita could be used in the regeneration of rural and urban waters (should those survive in fresh water)and sewage schemes as well as most marine waters, due to its high effectivity in removing hydrogen sulphide from affected water. It is not the solution to global water pollution to fight chemicals with chemicals. Nature has provided an excellent and valuable resource that could enable absolute natural recovery within polluted marine ecosystems. We should dedicate ourselves towards such magnificent discoveries and help nature help itself. Research on these Sulphur bacteria(especially Thiomargarita namibiensis)is very recent and ongoing. I recently enjoyed the privilege of a 24 hour marine research ship cruise off the Namibian coast with marine biologists from the Namibian Ministry for Fisheries and Marine Resources, to obtain mud cores holding Thiomargarita namibiensis bacteria. Several chemical tests are done and biological reactions are studied to collect the necessary data concerning Thiomargarita namibiensis. The discovery of Thiomargarita namibiensis awoke worldwide scientific excitement and interest. Its application to solve the problem of global water pollution would be a spectacular scientific breakthrough for the human race.

The Neem Dream: "Nature vs. Malaria""

The purpose of investigation was to find and test an inexpensive and effective remedy against malaria. After a great deal of research, I learnt that an effective herbal remedy against malaria may be extracted from Neem (Azadirachta indica)leaves. This remedy is not very well known about all around the world, however, the Neem tree is found in many parts around the world and is therefore a very accessible and inexpensive remedy against malaria. The purpose of my project was also to inform people about the harmful effects of malaria on the human body, as well as to advise people on how to protect themselves.

Keeping Cool

My aim was to test the effectiveness of coolboxes under different\r conditions, to use this information to do comparisons using commercially\r available coolboxes and finally to build an effective and cheaper coolbox\r appropriate to Namibia\r The general method used to compare different coolboxes involved\r measuring the rate at which ice melted inside the cool boxes under\r different conditions.

Mushroom Cultivation

The first aim of my project is to learn more about mushrooms: their lifecycle, their structures, the nutritional value of mushrooms, the medicinal values of mushrooms as well as the biological importance of mushrooms.\r The second aim of my project was to find how mushroom are cultivated in the world and specifically how they are cultivated in Namibia, where climatic conditions are rather harsh for mushrooms. Through interviews, I aimed to understand why mushroom cultivation is not widely practiced in Namibia and what are direct economic advantages of mushroom cultivation in Namibia.\r The third aim of my project was to see whether I could find cheap and economic methods of cultivating mushrooms in Namibia, a semi arid country where humidity is so scarce.

Investigation on traditional medicine from plants in Namibia

My project is about investigation on traditional medicines in\r Namibia. This is all about plants and different herbs that different\r people in Namibia use for medicinal purposes. The objective of this\r project is to inform the world of how valuable nature is and how we can\r try to conserve nature’s treasure so that valuable knowledge cannot pass\r away with olden experienced herbalists. Understandably the enquiry\r into indigenous medicinal herbs arose from the need to expand the\r possibilities of ones own medical practice. It was very important for me\r to satisfy our farmer’s thirst for knowledge, which is what I want to do\r with the rest of the world.\r In this project I have included most but not all of the plants that we\r use in Namibia for medicinal purposes. Seeing that some of these plants\r do not grow in certain parts of the country, I have also tried to clone it in\r other parts of the country. I have also made a powder from one of the\r plant’s leaves and tested it on several people within the country.\r To conclude my findings and experiments I would like to say, let us\r try to take these precious knowledge left for us from our ancestors and\r maybe one day in the future we might need it in some ways.

SEAWEED ON THE NAMIBIA COAST EXTRACTION OF AGAR & USE OF KELP AS FERTILIZER

In Swakopmund we have a problem with seaweed deposits on our beaches. Tons of seaweed are throwni away yearly. The reason I did this project was to see if the seaweed on the Namibian coast can he used instead of just being thrown away.Seaweed is a rich source of natural minerals and vitamins such as calcium, potassium iodine and also Vitamin A, BI and K. The seaweed on our coastline cannot he eaten as the salt content is too high. Seaweed is a marine algae that works like a sponge absorbing nutrients and minerals from the water.I extracted agar (a jelly) from red seaweed called(GracilariaVerrucosa). I dried the agar and seaweed, and I also grew mushroom spawns and bacteria on the agar plates. Secondly, I researched the possibility of using kelp (Laminaria Pallida), as fertilizer and livestock supplements. The unemployment rate in Namibia is very high. With adequate financial resources and proper marketing, seaweed can he used to increase the economy. We can market the agar to pharmaceutical and cosmetic companies, and also supply it to the university for students in Biology to grow bacteria and other micro organisms. The ferti lizer can be used to boost agriculture in Namibia. It is cheap and the farmers will he able to p1 ant vegetables with better nutritional value.All this was done to promote of biggest natural resource to create more work and to find a way for the less fortunate to create a better life for themselves.

Sisa-Friend or Foe?

It is beyond my logistical ability to determine the extent of the sisal problem in Namibia and as such I have investigated the following aspects, which should be of value to countries such as Tanzania and Kenya where there are still large plantations of the sisal plant. There is also a need to establish industries in Namibia and it is for these reasons that plant has been investigated.

Low Cost Housing and Sanitation based on Hygiene

I live in the harbor town of Walvis Bay in the heart of Namib Desert which\r is surrounded by sea and dunes and both are famous in the world. Walvis\r Bay is situated in Namibia formally known as South West Africa.\r Walvis Bay is a fishing industry town with an international harbor\r The population of Walvis Bay is about 54000 people and growing daily.\r Our fish is daily exported to many European and some of Asian countries.\r Industry in Walvis Bay is contributing nearly 50% to the Namibian economy.\r The town has also been declared as an EPZ (Economic Production Zone). Its\r harbor serves as a corridor to the neighboring land locked countries.\r Walvis Bay offers more job possibilities than most other Namibian towns.\r Every year many jobless people, even foreigners, stream to this town to\r seek employment as laborers or as specialists in the various industries.\r These people are in need of accommodation and often have to make due\r with any sort of shelter in Walvis Bay.

Effect of colours on Solar Energy

-to prove my original hypothesis that colour affects the power that is produced by solar panels. \r \r - that the wavelength of an elctromagnetic wave affects the photon or quanta energy that the wave has.