SciTech

Better grip for tractor tyres

by Dhaneshi YATAWARA

Having an economy largely based on agriculture, Sri Lanka needs accelerated developments in the field, particularly in agricultural engineering. The attention of experts seems to be on the increase at present. It needs more and not less if we are to be on par with the global changes.

From primitive method to the new hi-tech

Folding type mud wheel

Different types of new mud wheels to suit varying soil conditions

Food production needs to be improved and we should reach a level to be self sufficient as a nation. Sri Lankan agriculture needs a facelift. Rice being our staple food, increase in its harvest has a greater impact on the food production. Rice is the staple food of 19 million Sri Lankans. According to statistics, 1.8 million farmers live on paddy cultivation. Over 7.3 million hectares are cultivated annually for paddy production in the country. However, due to low productivity farmers have not been able to supply the demand for rice in the country.

Adding value to this competitively emerging field the innovation of a folding type cage wheel for tractors developed by Dr. P.L.A.G. Alwis of the Faculty of Agriculture, University of Ruhuna can improve the grip of the regular rubber tyres of small and medium power tractors. Small and medium tractors became an important factor in paddy cultivation as an attractive alternative for land preparation using buffalo - the poor man's tractor. It can be due to the dwindling of the buffalo population or sociological factors.

This new cage wheel developed under a project funded by the National Science Foundation, can be considered as an important development for the farming sector. The use of this cage wheel comes in two folds - it can improve the use of tractors in wet land paddy field operations and in road transport.

"A tractor with ordinary high lugged rubber tyres works poorly in wetlands due to slipping and sinking. To overcome this problem, different types of gripping aids have been introduced including chains, tracks and cage wheels," Dr. P.L.A.G. Alwis said explaining his invention.

According to Dr. Alwis the technicians identify that the working of a tractor depends on a number of factors - the soil surface on which the tractor operates being the main factor deciding the efficiency of the equipment.

But conventional "Mud wheels" for a four wheel tractor have smaller outer diameter than the tyre to facilitate road transportation. Therefore when operating in the fields tyres touch the hard pan first and high slip takes place. Resulting a high travel reduction with additional time spent on the work including wasting fuel and man power.

This is a considerable economic loss for farmers and tractor owners and because of this I thought of designing and constructing this new folding type cage wheels especially with my experience in France during my PhD studies," the engineering inventor added explaining the pros and cons of the old machines.

The invented mud wheel consists basically of four foldable folders and inner mounting system. Each folder has outer cage and three parallel bars.

Rectangular and angle lugs are fixed to the outer cage of a folder. The inner mounting system consists of inner ring which is fixed to six legs and cross bars. Four foldable folders are arranged circularly on inner mounting system. This gives the capability to have a larger diameter inthe field operation and smaller on road transportation. Spring loaded key mechanism has provided to lock the folders at folded and un-folded position.

The four wheel tractor equipped with the designed cage wheel had 60% more field capacity and 28% more travelling speed when compared with the conventional cage wheel. The time taken to plough a hectare of land was decreased by 40% with the developed new cage wheels. Travelling time was also reduced by 14%.

The newly developed cage wheel has a quick mounting and dismounting system. It also gave an improved grip while ploughing fields as the cage wheel diameter was greater than the type in the expanded position. This folding type cage wheel can considered as a new aid for small and medium sized tractors used in both high and wet land conditions. The cage wheel has simple construction, good serviceability, high field performance in different soil conditions and low cost.

Rapid prototyping tech quick and cost effective

by Harshini PERERA

Moulds built by the Rapid Prototyping machine

Technology enables a nation to get into the state of development at any time. More than any other country, Sri Lanka should take necessary approaches to reach high in technology. Rapid Prototyping is also one such measure of technology. The University of Moratuwa has signed a tripartite agreement with Ministry of Industries and the National Science Foundation to equip the Engineering Design Centre with a Rapid Prototyping technology. This is said to be the first machine in Sri Lanka through which a designer can present his product in complete form to a potential client or to develop high end products that are required for specialised industries such as medical and aircraft.

The facility has cost Rs. 40 million for which the Ministry of Industrial development provided Rs.15 million and the balance Rs.25 million by the National Science Foundation out of the 2008 budget allocations.

Rapid Prototyping is a technology where the data is fed to the computer through software known as Computer Aided Design (CAD). Then the initial three dimensional appearance of the prototype is designed and fed to the computer in the machine. Inside the machine there lies a VAT, (a vessel) containing a polymer liquid in which the structure of prototype is created when the laser beam is placed on it. The structure is built on a platform on the supportive parts where it is created layer by layer. Therefore, liquid turns into solids with the application of light. Later, the supportive parts are extracted using a chemical. Finally, the prototype is put into UV oven to make it solid.

The service of this technology was available since 19 December 2008. It was established with the hope of enhancing the design and manufacture capabilities in electrical and electronic industry. Accordingly, not only the industry, but many industries which require prototyping technology such as gem and jewelleries, automobile, ceramic can rely on it as well.

This prototyping facility addresses the need of designer in supplying the prototype more quickly and cost effectively. For instance, if a designer wants to create the prototype built according to his imagination with metal or wood, it would take two to three months whereas this machine could do it within a maximum 26 hours. The Director of Engineering Design Centre, Eng. B.S. Samarasiri explained that this prototype can be used as the mould as well as the real product. "These prototypes can also be used as final products as in hearing aids and medical applications. Because of the high quality they come out which makes it easy. We have found out that they can produce any prototype whether it is simple or complicated. This facility was imported from Germany and an awareness program on this technology was conducted by a German engineer," he further added.

Eng. Samarasiri explaining further said that, they have already agreed to render service to Loadstar, Dankotuwa Porcelain, Alankara SKR (Pvt) Ltd. and LECO for their requests for prototypes." NSF, UOM and MID has decided to convey a 50% concessional price applicable to all small, medium and large (Employment above 50 workers) industries for the servicing of the machines.

We also consider the need of national award winners and one who has registered with the inventor's commission for the concessional price," he stated.

This technology brings sophisticated method to the designers and inventors deviated from classical methods of making modules. It enables many with research approaches and profitable approaches to market their products quickly and reasonably. At the same time since it is based in an educational institute, the technology can be efficiently transferred to the students.

South Asia's largest rivers threatened, warns UN

Water resources in three of South Asia's largest river basins are highly vulnerable, with millions of people at risk of increasing water scarcity, a new report has found.

The report - jointly released by the UN Environment Programme and the Asian Institute of Technology - studied the Ganges-Brahmaputra-Meghna (GBM), Indus and Helmand river basins, all of which span multiple countries within the region. It lists overexploitation, climate change, and inadequate distribution and use of water resources among the key threats to the three basins, calling for "a unique mix of policy interventions and preferred routes for future water resources development" to tackle these challenges. Jinhua Zhang, regional coordinator at the UNEP Division of Early Warning & Assessment told SciDev.Net that countries should cooperate more to improve how water resources are managed - particularly to control pollution and improve efficiency - to help stop further damage to these rivers.

The report assigned each river basin a vulnerability index, based on resources stress, development pressure, ecological health and management challenges. The GBM basin is most vulnerable, but water resource systems in the Helmand and Indus basins are also highly vulnerable.

Extreme population growth in the basins over the last century has put pressure on the region's water resources, while around two-thirds of the Himalayan glaciers that feed the basins are receding. Additionally, groundwater levels in the GBM and Indus basins are declining at a rate of two to four metres per year due to intense pumping.

In India alone the amount of water per head has decreased from 4,000 to 1,869 cubic metres in the last twenty years.

Zhang told SciDev.Net that further research is needed to identify the supply of glacial melt for a given area, the amount of wastewater generated by industry, and strategies for water treatment.

"The per capita availability of freshwater is declining, and contaminated water remains the greatest single environmental cause of human illness and death," he says. Improving our knowledge of the vulnerability of freshwater resources "is therefore essential so that policymakers can manage this vital resource for the benefit of their people, their economies and the environment,'' says Zhang.

The report was released this month and is the first of a series. UNEP is doing similar assessments in North East Asia and South East Asia.

(Source/SciDev.net)

For high quality 'blacklime'

ITI takes valuable steps:

Research Officer Neville Amunugoda

Food technology in Sri Lanka is at a dire need of significant developments strong enough to make a difference. Rich with a wide variety of fruits, vegetables and world renowned spices grown in optimum weather conditions, Sri Lanka has a promising future in the most competitive world food market, along with a technology to level up the product quality.

Identifying this requirement Industrial Technology Institute of Sri Lanka, recognised to be a centre of excellence in the area of Food Technology, has taken number of steps in promoting national food security and safety.

Black Lime

Following these steps Neville Amunugoda, Research Officer attached to the Food Technology Unit of the ITI designed and constructed a rack drier which can convert perishable lime in to a product called `Black Lime' or dried whole lime. This has a high export potential especially to the Middle Eastern countries as a spice.

According to the Internet in the world this dried lime is also known as Loomi, Lumi, Omani and Amani. This is a spice used in Middle Eastern dishes. According to traditions this black lime is made by boiling fresh lime in salt water and drying it.

Black limes are usually used in legume, seafood or meat dishes. They are pierced, peeled or crushed before adding them to the dish. After cooking they become softer and edible. They can also be powdered and added to rice dishes.

Powdered black lime is also used as an ingredient in Gulf-style `baharat'(a spice mixture which is also called `kabsa' or `kebsa'). It is very popular in the Middle East.

Black limes are strongly flavoured. They taste sour and citrus like a lime but they lack the sweetness of fresh limes. Because they are preserved they also have a slightly bitter, fermented flavour.

A promising industry

In Sri Lanka manufacturing black lime for export is a promising field in the food industry with great potentials in the world food market. Having a rich harvest of high quality lime, especially in the Dry Zone, is a highly favourable condition for this industry.

"A large amount of energy is required to dry lime. To make black lime farmers have to adhere to certain quality levels of the end product and to that lime can not be sun dried," Neville Amunugoda added.

This high energy is required to generate the heat to dry lime. In Amunugoda's invention this temperature required drying lime is generated by combustion of biomass.

As the researcher explained the present practice is to use electrical dryers to dry lime, which is costly for a medium or a small scale industry. Hence, biomass combustion can be a better solution since dry flammable agro waste is widely available in the fields.

The problem of using biomass is its smoke with unburnt carbon particles. This can lower the quality of the black lime. Addressing this problem Amunugoda found a solution to bring out a non-smoke dryer. This equipment can handle 60kg of lime at a time.

FT division

The ITI Food Technology division assists food industries by developing or adapting existing technology, providing necessary technical support providing machinery and equipment, providing assistance with identifying unit operations and establishing processing lines, and engaging in trouble shooting and other forms of consultancy. The scope of the unit also extends to the vital area of developing and promoting the production and distribution of nutritional and nutritionally enriched food in both rural and urban backgrounds.

The section also conducts research programs in the above areas, with applied problems being handled by multidisciplinary teams. These results and research findings provide income-generating opportunities for small and medium industries and are also transferred to industry partners for larger commercial operations. The FT Section conducts a range of training programs to meet various needs of the food industry, including the supervision of Undergraduate and Postgraduate students from national and international universities. In doing so, the unit also develops human resources for the industry at large.

Over the years the Food Technology Section has built up a reputation of expertise in the fields of cereal and bakery technology, Fruit and Vegetable Processing and Post Harvest Technology, Fish Processing and Waste Utilization Technology as well.

DY