全國中小學科展

南非

Universal Cable Tester

The purpose of the research was to develop en easy to use/ affordable\r product that can indicate defects in any kind of cable carrying an electrical\r current or signal without any damage to the cable… and if there are defects,\r it can show you the kind of defects.

Up the Creek

After an annual swimming rally in the Nahoon river, concerns were raised after several swimmers fell ill, complaining of possible symptoms of mild E.coli infection. Research was hence conducted to determine the following: \r \r \r The Nahoon River is safe for recreational activity in terms of faecal-coliforms and E.coli \r \r \r Whether the amount of rainfall affects these levels. \r \r \r If faecal pollution is present, to determine the possible point sources of the pollution \r \r \r To devise a method that needs no assistance from a laboratory, and could be done in a home environment at low cost. \r \r \r \r Procedures \r Colilert-18, (the reagent) contains nutrients which react to faecal-coliforms and E.coli in the sample. It causes samples to change colour when contamination is present. A dilution method (used by the Kowie Catchment Campaign) was used to test the severity of the contamination. The dilution levels were as follows: 1, 1/10, 1/100 and 1/1000. A control test was also performed. One Colilert capsule was divided among the five samples, which were incubated in a household stove at 37ºC for 18 hours. A sample was collected every four days and after heavy rainfall. \r The results were rated on a severity scale of 0-4, where a two was considered unsafe for recreational activity. If the undiluted sample remained clear, it was ra ted 0, if all the samples changed colour, it was rated as a four. The same rating system was used when fluorescing samples to test for E.coli. The daily rainfall level was compared to the levels of faecal-coliforms and E.coli. \r Conclusion \r As it has high levels of faecal coliforms and E.coli, the Nahoon River is not safe for recreational activity on a daily basis. \r Heavy rainfall causes the levels of E.coli and faecal coliforms to rise. \r The major source of the contamination is a stream entering the river from a newly developed settlement, and not a leaking sewer. \r This experiment has developed cost-effective home environment testing method which could be used in researching other rivers, marine environments, recreational waters and even drinking water by community researc

What really attracts boys to girls

The purpose of this research was to challenge misconceptions about what attracts teenaged boys to girls. It has been observed that some teenaged girls hold stereotypes about boys and believe boys are only attracted to superficial qualities like beautiful hair. The aim is to investigate differences between what girls believe boys find attractive about them and what boys actually find attractive about girls. Hypothesis: There is a significant difference between what teenaged boys find attractive in girls and what teenaged girls think boys find attractive. Procedure Background reading was done to discover which characteristics are commonly used to measure attractiveness among teenagers. A survey questionnaire was used for gathering data. To gather information for the construction of the questionnaire, 4 focus groups were interviewed. The groups were asked to determine indicators of attraction and repulsion. Two separate questionnaires were designed (one for boys and one for girls), based on focus group information, with similar questions which could be used to compare results. Questions were related to personality and looks. The research was representative as 399 teenagers participated in the final survey. Results were collated in Excel tables. Percentages were calculated by using a scientific calculator and Excel. A bivariate analysis was created to examine the main question: ranking qualities that attract boys to girls. A comparison was made between boys’ and girls’ opinions from different age categories. Mean averages were calculated for this question. Other questions were analysed using mode averages translated into percentage of each gender. Graphs were designed using the values calculated. Observations/Data/Results 72% of boys prefer a girl with average looks and an awesome personality but only 37% of girls believed that to be true. The average boys from 12-14, 15-17 and 18-20 year old categories agree that confidence, humour, a nice body, politeness and intelligence are the five most attractive qualities in a girl they would consider dating. The order of these five change across the age groups but are constantly the top five, however confidence and humour always trump a “nice body”. The average 12-14 and 15-17 year old girl overrates a nice body and underrates politeness and intelligence but confidence and humour feature in their top five. The average 18-20 year old girl agrees with the boys priorities. When defining what makes a girl beautiful, 68% of boys highlight personality traits and 59% of boys mentioned physical features. When noting what repulses boys about pretty girls, more than 50% of both sexes agree that smelling bad was most off putting. 52% of boys mentioned taking drugs as unattractive yet only 23% of girls recognized this as repulsive. Conclusions The data supports the hypothesis. Confidence and humour are more important to the average boy than a nice body across all age groups. The younger the girl, the less she understands what attracts boys. 63% of teenaged girls believe that looks are more important to boys than personality. This is clearly not true. 72% of boys value a great personality more highly than good looks.

The gyroscopic effect of bicycle wheels

The aim was to determine whether there is an amount of gyroscopic force that keeps a bicycle wheel upright and stable. Two hypotheses were used, the first being as the mass of a wheel increases so does the force required to tilt the wheel by thirty degrees and the second that as the speed at which the wheel is spun increases so does the force required to tilt the wheel.

The Effect of Hands Free - Cell Phone Conversation on Visual Fields

It is a known fact that using a cell phone while driving can lead to reckless driving. According to research done by the World Health Organisation (2011) thousands of car accidents occur worldwide, each day, due to cell phone use whilst driving. Many of these car accidents result in serious injury or death of drivers, passengers or pedestrians. According to the Automobile Association (2012), cell phones are the number one cause of traffic accidents in South Africa. The high rate of car accidents due to cell phone use has led to legislation being passed, in most countries, banning hand-held cell phone use while driving. Hands-free phone equipment is not prohibited as it is widely regarded as a safe means of making and taking a phone call while behind the wheel. The purpose of this study was to show that the act of talking on a cell phone and not the method of talking (hand-held versus hands-free) increases accident probability. This study used a Friedman Visual field analyser which measures subject’s visual fields with and without engaging in hands-free cellular conversation. The results showed a significant constriction of the visual fields when subjects were conversing on a cell phone. These results were and can be explained by the fact that the test subject experiences cognitive distraction. Cognitive distraction occurs because the driver has to divide his/her attention between the cell phone conversation and the tasks relating to driving. These results have significant ramifications for road safety in a driving environment.

The impact of climate variability on infectious disease

Diarrhoea is an infectious disease that claims many lives (particularly among infants) and is known among many other infectious diseases, to have a relationship with climate. This projects quantifies this relationship by comparing health insurance treatment claims for diarrhoea and anti-diarrheal drug sales data from the private health sector with temperature and rainfall data provided by the South African Weather Service. The data were then analysed and show that incidence is highly seasonal and varies among regions with different seasonal climates. The results show that climate variability can explain 73% of diarrhea incidence variation with rainfall explaining 8% and minimum temperature explain the other 65 %. Preliminary predictions of future monthly percentage increases in incidence were then made for a series of time ranges. This project demonstrates that with predicted climate data one can predict future variations of diarrhoea allowing the health sector to be adequately prepared.

Robotic Search and Rescue

I built a robot that is able to improve safety in mines. The robot takes a series of sensor readings, do 3D mapping to compare deteriorating physical conditions in time, detect CO and CH4 levels and record video footage. All of this information is then sent back to the user. The project aims to build a robot that could decrease the amount of casualties in mines due to gas or instability. A strict engineering process, which comprised researching different features on a robot, was followed. A prototype robot was built, tested and improvements made. Some of the challenges faced, while building the prototype robot, included manoeuvrability over any type of terrain, even rough and rocky terrain. Choosing the correct driving mechanism (wheels, tracks, suspension and steering) also proved to be a very important feature that had to be kept in mind. The sensors used included, a temperature, humidity, carbon monoxide gas, as well as a methane gas sensor. A Gyro, Accelerometer and compass for easier navigation were also used. Two cameras which included a front camera for navigation and 3D mapping as well as a back camera for navigation were installed. The robot was tested over various terrains, it was able to retrieve sensor data and all of the engineering goals were reached. After the robot was built it was tested on various terrains. The robot achieved all of the engineering goals. The sensors was able to give readings, the robot 3D mapped an area and was also able to manoeuvre over rough terrain.

Using EEG Neuro-Feedback technology to control a prosthetic hand

Unaffordable healthcare and excessive plastic waste are both alarming issues that are plaguing modern society. Recent studies conducted by the World Health Organisation (WHO) report that about 15% of the world's population suffer from a form of disability, of which 50% of the demographic cannot afford adequate health care. Furthermore, 8 million metric tons of plastic annually enter our oceans (apart from the 150 metric tons that currently circulate our oceans!). In conjunction to the global plastic pollution crisis, unnecessary invasive surgery is currently being done on amputees. Many of these desperate patients are forced to pay exorbitant prices in order to live a normal life with bionic prosthetics. The solution… Project Limbs - an EEG, 3D printed prosthetic printed from recycled plastic. Signal processors will be implemented to build an affordable and easy-to-use ‘mind controlled prosthetic hand’, that requires no invasive surgery.

Sunprints in the sky

Revealing fascinating and educating concepts in a field of astronomy usually requires expensive equipment. Therefore, most schools have very little practical equipment to teach astronomy. I wanted to investigate the Sun’s track using a simple apparatus that can be afforded by many schools instead of using an expensive one.

AGRIBOT – ROBOTIC SOLUTION TO FOOD SUSTAINABILITY

Food sustainability is key to human survival. Robotic solutions have started playing large roles in automating farming tasks in order to assist with crop yield and the efficiency of production. Due to the unreliability of and lack of manual labour in many parts of the world, Agribots are playing bigger roles. One of the biggest advantages of Agribots is that they can operate 24/7, 365 days a year without payment. Agribots are being used more often in dairy farms to milk cows while others are used to shear sheep. Agribots are fast becoming very important to farmers by gathering valuable data; milking cows; automating animal feed; measuring the right amount of pest control, detecting weeds and pests, harvesting and ploughing with unmanned tractors. In many parts of the world farm labour is scarce and difficult to come by. In 南非 for example farm labourers endure gruesome attacks. These attacks on farmers result in the closure of the farm for an extended period of time resulting in the loss of large quantities of crops. Food sustainability is dire in Africa and many parts of the world. “Each day, 25,000 people, including more than 10,000 children, die from hunger and related causes. Some 854 million people worldwide are estimated to be undernourished, and high food prices may drive another 100 million into poverty and hunger. . 90 percent of the world’s farms produce over 80 percent of the world’s food. They also manage about 75 percent of farmland worldwide. Yet, paradoxically, these farmers are often poor and food insecure themselves. Due to the increase in the world’s population annually, there is a growing demand for food. This has led to increasing pressure on farmers to produce crops. In order to meet this demand, farming innovations are vital for the future of food and agriculture. Constant innovations in agriculture is thus needed to constantly feed a growing and increasing population. Innovation in agriculture is also critical to help farmers use resources in better and more efficient ways. “Innovation is one of our best tools for creating a #ZeroHunger world.