NSF Research Highlights

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A new species of box jellyfish, Carybdea wayamba sp. nov. (Cnidaria: Scyphozoa: Cubomedusae: Carybdeidae) from Sri Lanka

Sri Lankan researchers discovered a new Jellyfish species for the first time. It's a Box Jellyfish and about 50 species of Box Jellyfish have been discovered worldwide so far. In honor of North Western University of Sri Lanka, the species has been named as 'Carybdea wayamba'. Financial sponsorship for research by National Science Foundation (NSF).

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A BIO-PESTICIDE FROM BANANA FRUIT PEEL

A team of scientists from the Faculty of Agriculture, University of Peradeniya has developed a bio-pesticide from the banana fruit peel that can control post-harvest diseases in banana.

The bio-pesticide dip developed from harmless microorganisms living on the banana fruit peel competes with and destroys the disease-causing pathogens, extending the life of the banana.

Banana is a widely consumed fruit in Sri Lanka. Approximately 50,000 ha are under banana cultivation, producing 450,000 metric tons of edible fruits annually. Anthracnose, most common post-harvest diseases seen in dessert banana.

Banana which was considered a home-garden crop several decades ago is now given a high national priority among food crops. Approximately 28 cultivars belonging to two principal types of banana (i.e. cooking type and dessert type) are available locally. The banana industry is affected by several diseases, caused by both bacteria and fungi, that set in after harvesting the fruits. This crown rot and blossom end rot are the leads to the reduction of post-harvest life and quality of the fruits.

The bacterium Burkholeria spinosa, the most effective of all isolates has certain other advantages too:

  1. The edible parts of banana are not contaminated by the bacterium when the fruits are treated with spinosa postharvest dip,
  2. the bacterial dip treatment effectively controls three postharvest diseases of banana that develop on a range of banana cultivars,
  3. more effective control of post-harvest diseases can be achieved by pre-treatment with hot water (500 for 3 minutes, prior to the bacterial dip treatment,
  4. the spinosa bacterial dip can also control several post-harvest fungal diseases of other tropical fruits such as mango, pineapple and avocado.
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A fertilizer from RICE straw

Microbiologists from the Faculty of Agriculture, University of Peradeniya have isolated indigenous soil bacteria and fungi that can accelerate the decomposition of rice straw in wetland rice fields.

Inoculant mixtures have been formulated with several bacteria and fungi. These inoculents can be recommended for fresh rice straw from new improved varieties used in wetland rice fields.

For more than four decades, high yielding rice varieties were widely grown with the use of chemical fertilizer in all rice cropping systems of Sri Lanka. However, yield stagnation of rice was recorded in many parts of the island in the early 80’s, due partly to the decreased fertility of rice soils.It has been shown that adding rice straw at a rate of 4 tons per hectare could provide the total potassium requirement and 30% of the nitrogen requirement of the rice crop.

Recycling of rice straw is not practiced by many farmers mainly due to high labour costs involved in bringing straw to the field and the difficulty in harrowing and ploughing the field in the presence of fresh straw. The best option to overcome this situation is to have the straw decompose quickly. However, under natural conditions, fresh straw should undergo decomposition for a period of about a month to become brittle. The slow decomposition of rice straw is due to its high lignin and cellulose contents. Only a few types of bacteria and fungi can decompose cellulose and lignin in rice straw. Therefore, speeding up of the decomposition process of rice straw by introducing such organisms would help overcome difficulties arising in land preparation for paddy cultivation.

The mixed inoculants of bacteria and fungi isolated by the researchers from the Faculty of Agriculture, University of Peradeniya decomposed straw rapidly with a weight reduction of up to 50% in 20 days. The decomposed material was also found to be high in nitrogen.

Incorporation of composted material in rice fields increased plant growth, number of tillers and yield under field conditions. Since these inoculants performed equally well at Kegalle in the absence of chemical fertilizer, and at Peradeniya in the presence of chemical fertilizer they could be recommended for both production systems.

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A NATIONAL LABORATORY TO ENSURE SAFETY OF ANIMAL PRODUCTS

Anti-microbial agents used in the treatment of animals or feed additives used as growth promotors may remain in processed food products and cause unfavorable health conditions to the consumer.

Consumers both in Sri Lanka and other developing countries have become more and more quality conscious when selecting food for consumption. This is specially true for animal products since todays animal food industry uses intensive methods of production that may involve the use of feed additives, antimicrobials and growth promotors.

There is an increased demand for producing animal proteins as food, to meet the worldwide food shortage. To fulfil this consumer demand, today’s food industry uses many intensive methods of animal production.

Quite often farmers use drugs such as antimicrobials, feed additives and growth hormones without adequate veterinary supervision. In such instances there is a possibility that some of these drugs will remain in animal products and when people eat such food, several unfavorable reactions may result. Direct effects such as toxicities and allergies, or indirect effects such as developing antibiotic resistance occur. This therefore, is a significant public health concern.

Routine residue testing is therefore a necessity to ensure the quality of food products. Anti-microbial residue monitoring programs of food commodities are well established in developed countries where they maintain high standards for their food products. Such residue monitoring facilities were not available in Sri Lanka until a team of scientists from the Faculty of Veterinary Medicine and Animal Science, University of Peradeniya embarked on setting up bioassay methods for detecting drug residues in food commodities.

Bioassay methods to identify six different types of anti-microbial agents namely penicillin, tetracycline, sulphonamides, streptomycin, quinolones and erythromycin in milk, milk products, meat, eggs, fish and shrimps have now been set up.

The studies have also shown that a majority of the tested samples were free of measurable levels of residues. The tested samples included broiler samples from processing plants and retail markets and shrimp samples from export consignments.

The anti-microbial residues in food can be further reduced through farmer education and regular veterinary inspection.

Veterinarians should promote alternative management practices such as vaccination of poultry, Good Agricultural Practices (GAP) and Good Veterinary Practices (GVP) that would reduce the use of antimicrobials in the poultry and shrimp industry.

The screening tests thus set up are now used by quality certified poultry processors and shrimp exporters in order to meet the standards. This method is also in use at Regulatory Authorities including the Ministry of Fisheries and the Quarantine Division of the Department of Animal Production and Health. The facility serves as the National Center for testing livestock and aquatic food commodities for antimicrobial residues which is a must for food quality assurance.

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AUTOMATIC DETECTION OF LIGHTNING STRIKES

Every year local newspapers and other media report damages due to lightning strikes in various parts of Sri Lanka. The frequency of such strikes is generally higher during the inter-monsoon season. However, there are no institutions that maintain accurate records on lightning parameters such as strike locations, flash strengths or hazardous areas in the country. Such information is critical when selecting sites to establish industries, especially related to electronics and IT.

A team of scientists from the Department of Physics, University of Colombo implemented a lightning detection network that is capable of recording the point of strike of lightning flashes that strikes in and around Sri Lanka.

Several lightning Direction Finding (DF) stations donated by IPPS Uppsala University Sweden were utilized in implementing the lightning locating network. A DF station consists of a crossed loop antenna, a flat plate antenna, and a set of electronic units to process the detected lightning generated electromagnetic (EM) fields. The electronic units are capable of identifying cloud-to ground flashes that occur within its typical range of about 400 km with 80% efficiency. Each DF station is capable of finding the time of the occurrence, direction, strength and the multiplicity or the number of return strokes in a single flash. If there are at least two DF stations at a considerable distance from each other with known locations, one can localise the striking point of the lightning. With the lightning data recorded during 1999-2002, several studies were carried out, namely the study on the activity of lightning strikes in this region, the measurement of lightning peak currents over Sri Lanka, and the seasonal variations and characteristics of lightning observed during monsoon and inter-monsoon thunderstorms.

The research work conducted under this project produced results that can be utilized at National level. Some of the parameters studied have yielded valuable data that could be used in designing lightning protection systems for Sri Lankan conditions. In a subsequent study, the possibility of using compact Anisotropic Magneto-Resistive (AMR) sensors to measure the magnetic fields generated by lightning flashes were tested. It was concluded that due to easy maintenance and higher accuracy, the new setup could be used to implement a real time lightning detection and monitoring system in Sri Lanka.

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BATS - STUDY REVEALS THEIR AMAZING HABITS

A study of Sri Lankan bats carried out after a period of 70 years has revealed some significant information that would help conserve these truly amazing animals useful to mankind.

Bats like humans are mammals, delivering babies that feed on milk but are special due to their ability to fly.

Nearly 842,840 individual bats were identified during a survey carried out by a team of scientists from the University of Colombo, in all parts of Sri Lanka excluding the North and the East of the island. It covered all major climatic zones. There are two main groups of bats; the insect eaters that are smaller in size (microchiropterans), and fruit eaters that are much larger (megachiropterans). Bats are the most vulnerable group of animals to environmental changes due to their unique and specialized resting, feeding and reproductive habits.

Bats help people in several ways. They eat thousands of insects harmful to humans and crops. They help disperse seeds and pollinate flowers. The blood thinning chemical in the saliva of vampire bats has been studied for its medicinal value. The echo-location mechanism of the insect eating type has helped in studies to assist blind people. In addition, bat dropping is the best plant fertilizer known to man. Sri Lanka being a tropical country accounts for a remarkable variety of bats. However, very limited information was available on bat types (species), population sizes, their habitats, feeding grounds and reproduction.

This work recorded 19 different types (species) 60% of bat types recorded in the 1920s by Phillip’s survey. Population sizes of fruit bats had increased alarmingly, while those of the insect eating bats had strikingly declined during the last few decades due mainly to human interference: direct actions such as consuming bat meat and indirect actions such as new human settlement schemes, deforestation and population increase leading to loss of bat habitats. This study also collected new information on selection of places for resting, their movements and reproduction. Bats were found in three types of day roosts: tree based, manmade and rock based. Some bats were highly specific in roost selection of bats which accounts for only whereas others were ambiguous in their choice of roosts. Some bats (Cynopterus bats) preferred to construct ‘tents’ by bending leaves of palm trees, which was recorded for the first time in Sri Lanka.

Breeding periods of some Sri Lankan bats were described for the first time. Two breeding cycles dependent on the geographic locations were found for two bat types. Some bats used separate ‘maternity’ caves to deliver their babies and to nurse them. Several such ‘maternity’ caves have been identified. Migration between ‘maternity’ and ‘pre-maternity’ caves was documented for the first time.

Every animal has a role in the environment, so do bats; therefore, it is important that we protect them. The information gathered from this study will help conserve bats.

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CAUSES AND OCCURRENCES OF OVARIAN CYSTS IN SRI LANKAN FEMALES

Polycystic Ovary Syndrome (PCOS) that affects about 10% of all females is the most common hormonal disorder among women of childbearing age. It is a leading cause of infertility. Awareness of PCOS has increased in the western world but very limited studies have been done in the South Asian region.

The ovaries are the female reproductive organs that produce eggs and sex hormones, mainly oestrogen and progesterone. Ovaries also produce androgen or “male” hormones but in small quantities. These hormones regulate a woman’s menstrual cycle and the release of eggs from the ovary (called ovulation).

In normal menstruation, eggs are released from follicles - cysts that burst to release the egg. One dominant follicle develops with each menstrual cycle and after ovulation the follicle remnant shrinks and disappears.

However, if an ovary produces abnormal quantities of hormones, especially androgen, it interferes with egg development and release from the ovary. The failure to ovulate - the release of the egg - would mean that follicles remain in the ovary for long periods of time. The accumulation of follicles lead to the condition called PCOS (ovarian cysts) where the cysts may appear as a ‘string of pearls’on ultrasound examination. Thus, women with PCOS are not ovulating or releasing an egg each month, but instead will show irregular or missed menstruation periods. The prominent symptoms of PCOS are overweight, lack of regular menstruation and excessive production of male hormones. The symptoms and severity of the syndrome vary greatly between women.

This community based study carried out by a team of researchers from the Faculty of Medicine, University of Colombo, in 4 Divisional Secretariat areas in the Gampaha district on a sample of 3030 women of the age group 15-39 years revealed that irregular menstrual cycle was a common problem in 8.1% of women. 6.2% of them had reproductive hormone related disorders. PCOS being the most common, accounted for 6% of such disorders.

This study also found that if PCOS is not treated it can lead to many health problems. Women with PCOS were more likely to be childless, over weight, suffer from high blood pressure and diabetes. Cancer of the womb is associated with prolonged menstrual cycles occurring over a long period of time. There is also a less well defined association with breast cancer. Since there is an increasing diabetic trend and most cases of PCOS occur in young girls it is important to diagnose PCOS early. Although the women with PCOS bear up the symptoms in silence the impacts it could have on the society, economy and the nation as a whole could be enormous.

Findings of this study would be useful for health planners to develop programmes to diagnose PCOS in the early stages in order to properly manage the disorder.

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        Continuous mapping of agricultural production, marketing and supply

 

A Mobile based Agriculture Information System was developed by the University of Colombo School of Computing (UCSC) in collaboration with three foreign institutions.

This Mobile Application provides a unique opportunity to farmers on an individual basis, to cultivate and market the required crops in a cost-effective way in any desired geographical location. Installed on a smart phone, it can provide real-time information for selecting crop varieties suitable for a given location, estimate the cost of production based on information on fertilizer and pesticide requirements and their present market price, view prices being offered to a particular crop in and around the site of cultivation, and even get advice from relevant authorities in case of a pest or a disease outbreak. Lack of relevant information on a real-time basis has created many difficulties to farmers (e.g. over production and lack of a market for the product) as they have not been able to make the right decisions at the right time relating to their farming activities.

The web-based crop forecasting system that has been developed by the Department of Agriculture with technical expertise from the UCSC was deployed by His Excellency the President in 2017. This system, based on its degree of operation, will provide timely and reliable information on extent of cultivation, expected production, marketable surplus etc. of various food crops grown in the country. The information accessible at Agrarian Service Centres, or any other point at District and National level, could be used for risk mitigation as well as in decision making for planning and implementing crop production programmes. The Ministry of Agriculture intends to use this programmes in the future for monitoring food production island-wide and implement the fertilizer subsidy and crop insurance schemes.

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Early presence of humans in Sri Lanka and continuum of their existence towards Holocene

A research grant awarded under the discipline of Indigenous Knowledge titled “Climate change and the human adaptations in the early and the middle Holocene in Sri Lanka,” was successfully completed in 2018. The Research Team consisted of Prof. Raj Somadeva, Dr T R Prematilleke and Dr Nimal Perera of the Postgraduate Institute of Archaeology.

This research project was aimed at studying the human existence and its continuity in Sri Lanka during the Holocene geological epoch. Early presence of humans in Sri Lanka during the middle and late Pleistocene has already been proven by archaeologists and physical anthropologists. However, the continuum of their existence towards Holocene has not been scientifically proven.

During the investigations done in the two-year period, five prehistoric cave occupations in and around Balangoda, associated with three distinct climatic zones, have been observed. Six excavations carried out during the project period have yielded a fairly large assemblage of artifacts which reflect the behavioral traits of prehistoric communities who occupied the investigated locations. Scientific dates (AMS) obtained have proven that all the caves excavated were inhabited by the prehistoric communities during the Holocene. Most striking evidence unearthed was a collection of plant residues (charred seeds) that has been dated to the mid-Holocene (4500 - 3450 BCE). Evidence reflecting an emerging new materiality of those prehistoric communities was identified. The sites and the artifacts together with Carbon-14 dates reiterate the fact that the hunter-gatherer/ foragers of the mid/late Holocene had been receptive to the climatic changes of the contemporary period and the adaptive response is reflected in their material culture.

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HEALTH BENEFITS FROM BLACK TEA

Tea is the most commonly consumed beverage in the world after water. A study has shown for the first time that Sri Lankan black tea possess a plethora of bioactivity that could be of potential health benefit to man.

Sri Lanka is well known for its high-quality tea and as the 3rd biggest tea producing country globally, has a production share of 9% in the international market and one of the world’s leading exporters with a share of around 19% of the global demand. Black tea accounts for 78% of world’s tea production and about 80% of global tea consumption. Sri Lanka produces about 310 million kg of black tea per year.

Studies conducted with mice and rats at the University of Colombo have provided convincing evidence that Sri Lankan Black tea has the following potential health benefits. It can:

  • prevent blood clots
  • dissolve blood clots
  • protect stomach lining from ulcer formation
  • heal gastric ulcers
  • reduce anxiety
  • lower the sugar level in blood
  • reduce fever condition
  • reduce pain
  • prevent diarrhoea
  • increase urine quantity passed
  • reduce elevated blood cholesterol levels
  • increase sexual desire
  • prolong the onset and shorten the duration of sleep
  • increase head movement or lateral head displacement of sperms

The ability to dissolve blood clots, protection given to the stomach lining, reduction of fever condition and influence on sexual desire (the aphrodisiac properties) of Sri Lankan black tea are new findings for any type of black tea, produced in the world. However, no antimalarial activity was exhibited.

This study also proved that drinking tea even in large quantities does not cause harm to kidneys or to the liver. Furthermore, it was established that drinking tea was not disruptive to female oestrous cycle, pregnancy or to male fertility.

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Improving fruit quality and post-harvest life of lime

There is a constant demand for fresh lime throughout the year as it is used domestically, in the food processing industry and as an ingredient in indigenous medicine. It is also identified as one of the high priority crops. According to FAO statistics (2017), the area under cultivation of lemon and lime in Sri Lanka is 12.14 ha with an annual average production of 6,640 tons in 2014. Lime crop thrives well in the dry and intermediate zones of the country, where it can be found as medium-scale orchards or as scattered trees in home gardens. There are growth variations and the peak season falls between April to July.

During the peak season, the lime growers leave the fruit without harvesting as the income is insufficient to recover the cost of production. Therefore, study of fruit phenology & development of Research at Bench and Beyond Research at Bench and Beyond Improving fruit quality and post-harvest life of lime maturity indices, manipulation of narrow fruit season targeting early or late season marketing & developing appropriate storage strategies for programmed year-round marketing would be highly beneficial for sustainable lime production and processing.

A Competitive Research grant completed in 2018 from the discipline of Agriculture and Food Science resulted in developing a color chart that can be used by lime growers to identify the best harvesting maturity based on the peel color which will aid in fetching a better market price and maintaining fruit quality for an extended time period. This grant was awarded in 2015 to Dr W A Harindra Champa of the Institute of Postharvest Technology and the study was carried out with the aim of studying fruit phenology, maturity manipulation, fruit season and development of appropriate storage strategies for year-round marketing.

The study resulted in finding optimum harvest maturity for fresh market and storage purpose and the optimum doses of pre-harvest foliar sprays of gibberellins, brassinosteroids and salicylic acid to advance, accelerate or delay the development stage of lime. These major findings are directly beneficial to lime growers in Sri Lanka which can aid development of lime-based agribusiness leading to generation of employment opportunities.

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Integrated food production systems

The project “Development of sustainable integrated food production systems to enhance household food and nutritional security, economic growth and livelihood of resource poor families in the Northern Region of Sri Lanka” was implemented successfully in selected five districts namely, Jaffna, Kilinochchi, Vavuniya, Mullaitivu and Mannar. Based on the population in resettled areas, families were selected and a survey was conducted to assess the livelihood of people especially with resource availability in terms of manpower, infrastructure, income generation, diets and living standards. After the survey, one home garden in each district was selected as a model and training programs were conducted periodically to educate the other families in the district of home gardening concept under this specific project to uplift their livelihoods.

Over the reporting period of 3 years, the livelihood of the resettled people improved immensely. The simple innovations, e.g. cages and baskets made of old bicycle rims, vehicle tyres, palmyrah leaf etc., and the use of household Research at Bench and Beyond waste to enrich the sandy soils, allowed the families to grow leafy vegetables and other vegetable crops in their home gardens improving their nutritional status. The home gardens also provided fresh fruit such as mango, guava and banana and vegetables such as onions, moringa and brinjals for home consumption. These became supplementary sources of food and in many cases brought-in an additional income too to the families. It is reported that some families earned as much as Rs. 10,000/- per month as additional income from their home gardens.

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Measuring sea level variability contributing to urban planning and coastal zone management

Understanding that long-term sea-level variability is the key to recognizing future variability, a Research Grant awarded in 2014 to a team led by Dr Pradeep Nalaka Ranasinghe of Department of Oceanography & Marine Geology, University of Ruhuna was successfully completed in 2018 contributing to the development of a long sea-level record for the Central Indian Ocean and to identify forcing mechanisms.

Warming of the atmosphere due to greenhouse gases and melting of polar ice is causing a significant rise in the sea-level. Reconstructions of sea level history in the Central Indian Ocean do not run beyond Holocene due to lack of long-term records. Further, available sea-level history for the Central Indian Ocean runs into doubts due to inconsistency of available records for the Holocene.

There have been several unresolved issues on Holocene reconstructions of the region. Accordingly, this study was carried out with the objective of finding solutions to the said unresolved scientific problems as it would explain the impacts of global anthropogenic sea level rise to the coastline of Sri Lanka as well as South India.

According to the results, three phases of island formation during the Miocene, Pleistocene, and Holocene could be recognized in the Palk Strait area. Changes in sea level have resulted in these island formations. It was recognized that future anthropogenic sea level rise could submerge a large area of coastal lowlands in the South and in the Jaffna peninsula. This study also glimpsed the coastal landscape changes at the anthropogenic sea-level rise. According to the gathered data, coastal lowlands including Jaffna peninsula will be at risk with the rising sea level. This information can be used for urban planning and coastal zone management as modeling the coastal areas with accurate levelling data is essential to predict flooding areas at different levels of sea level rise in future.

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NSF Contributes to improve the Tea Industry

Withering of tea is an essential and important processing stage in black tea manufacturing. At present, there are about 700 factories in operation processing black tea. It is absolutely important to have a uniform withering within a reasonable time period which varies from 12-16h. Withering consumes comparatively high electrical energy which is about 48% out of the total electricity consumption in the tea factory. In order to reduce the power consumption, some factories installed Variable Speed Drives (VSDs) for withering troughs. However, all the operations are done manually. As such, the benefit of using VSDs is negligible.

The Tea Research Institute with NSF support developed a system to reduce the electricity consumption establishing an automatic control system for VSD. Technical expertise, for this project, especially for electronically controlled parts is being provided by the University of Moratuwa.

Test trials have provided promising results with saving of electrical energy up to 0.18 kWh/kg. In this context, if the adaption rate of the newly developed control system for tea withering is 60% of the total 700 factories of the country, about 40 GWh annual saving of electrical energy can be expected from the tea sector. The project is expected to be completed within three months and the system will be available for the stakeholders in the near future. The successful completion of this project is undoubtedly essential for the sustainability of the tea industry in Sri Lanka.

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Safer Communities with Hydro - Meteorological Disaster Resilient Houses

Damages to human lives and habitats due to torrential rains and floods have intensified in the recent past in Sri Lanka. Identifying the importance of this area, NSF facilitated the research project on “Safer Communities with Hydro-Meteorological Disaster Resilient Houses” conducted by Prof. Chintha Jayasinghe, Professor in Civil Engineering, University of Moratuwa in collaboration with Bath University, United Kingdom.

This research project was successfully completed and the NSF organized a Knowledge Sharing Programme on 30th January 2019 to disseminate the findings of this research project which was held with the participation of senior academics of universities and senior officials from several government institutions. The resource persons were Prof. Chintha Jayasinghe and Prof. M T R Jayasinghe, University of Moratuwa.

During the study, nature and magnitude of the problem related to flood damage including socio-economic impact was investigated for selected areas in Matara, Kalutara and Galle Districts, the areas highly affected due to floods in 2016 and 2017. Experimental models for minimizing the damages to structures were studied at Bath University, UK. The study was concluded with the findings to improve the flexural strength of masonry walls using steel reinforced mesh, constructing a cost-effective refuge space which can be used as part of the house or building and having upper floors to escape in case of flash floods. Implementing these findings at field level will enable to minimize structural damages to buildings and negative socioeconomic impacts due to floods in future. Further, improvement of cost-effective construction of the refuge space by incorporating innovative building materials (e.g. waste-based building materials) are being researched at the laboratory level.


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