This community contains all other publications produced by the University Academic Members. http://ir.lib.ruh.ac.lk/handle/iruor/7340 2026-08-14T19:19:48Z 2026-08-14T19:19:48Z Warnasooriya, S.R. Jayasinghe, A.D. Asanthi, H.B. Kodithuwakku, E.P. http://ir.lib.ruh.ac.lk/handle/iruor/21591 2026-08-14T04:02:40Z 2024-03-07T00:00:00Z

Bactericidal effect of nanosilver synthesized with Neolitsea cassia mucilaginous extract. Warnasooriya, S.R.; Jayasinghe, A.D.; Asanthi, H.B.; Kodithuwakku, E.P. This study focused on green synthesis of silver nanoparticles using mucilaginous leaf extracts of Neolitsea cassia and demonstrating the bactericidal effect of the product against Staphylococcus aureus and Escherichia coli, which are common in polluted water. A concentration series of silver nitrate was subjected to four treatments by mixing with separate (a) aqueous and (b) 80% methanol extracts of N. cassia leaves in (c) atmospheric and (d) nitrogen gaseous environments, for comparison. A linear increment of the dry weight of silver nanoparticles was observed with increasing silver nitrate concentration (r = 0.99, p = 0), resulting in higher yields from 80% methanol extracts in an atmospheric environment. As characterized by surface plasmon resonance absorption, energy-dispersive X-ray spectroscopy and scanning electron microscopy, quasi-spherical crystalline silver nanoparticles of 11.7nm average diameter were synthesized. The disk diffusion method showed that the growth of E. coli and S. aureus in culture media was increasingly inhibited with increasing nanoparticle concentration (r = 0.95, p = 0 and r = 0.93, p = 0, respectively). It was concluded that 80% methanol extract in an atmospheric environment was the most productive way to green-synthesize silver nanoparticles from the mucilaginous sap of N. cassia.

2024-03-07T00:00:00Z Shantha, K.Y.H.D. Pathiraja, P.M.Y.S. Ranatunga, Y.M.M.K. Rajawatta, K.M.W. http://ir.lib.ruh.ac.lk/handle/iruor/21560 2026-08-11T07:37:45Z 2024-01-01T00:00:00Z

DEVELOPMENT & EVALUATION OF JACK OPERATED HERBAL JUICE/OIL EXTRACTOR FOR AYURVEDIC MEDICINE PREPARATION Shantha, K.Y.H.D.; Pathiraja, P.M.Y.S.; Ranatunga, Y.M.M.K.; Rajawatta, K.M.W. Sri Lanka has a rich indigenous system of traditional medicine known as Ayurveda, which combines Sinhala traditional medicine, Indian Ayurveda and Siddha systems, Greek Unani medicine through Arab influence, and the unique Desheeya Chikitsa. The objectives of this research were to identify the essential practices for equipment development in the Ayurvedic sector, to examine the scientific principles underlying traditional practices, and to design Ayurvedic machinery. To achieve these goals, a needs identification survey was conducted involving over 10 institutes in Sri Lanka and more than 300 indigenous doctors across the country. Data were collected from 120 of these doctors to ascertain the specific requirements of the sector. In Ayurvedic preparations, herbal juice extraction is done manually, and ‘Pehe’ is used to extract oil from hard materials like “mee” and to extract the remaining oil from Kalka, making the process time-consuming and labour-intensive. To address this challenge, a hydraulically operated juice/oil extractor was designed to fulfil one of their requirements. This machine operates at low temperatures, which helps to preserve the nutrients and flavour of the juice/oil. It is operated using 4-ton hydraulic jack. Extracted juice percentages (wet basis) were 65% and 60% for Gotukola and Neeramulliya leaves respectively. Extracted oil/juice % (wet basis) were 36%, 48.89%, 19.8%, 20.4%, 68.52% and 52% for Mee (without steaming), Mee (steamed), Sesame (black), Sesame (normal), Nelli (without seeds) and Nelli (with seeds) respectively. Results revealed that using this method juice/oil can be extracted efficiently using this extractor than traditional methods. An extractor is a portable device which can be operated by a single person. Since the raw material contaminating machine components of the extractor are made of food-grade stainless steel, the hygienic extraction process is secured. The extractor has a capacity of approximately 3 kg of crushed leaves or 1 kg of crushed seeds per batch. Over 100 machines have been distributed to small and medium-scale Ayurvedic practitioners involved in medicine preparation.

2024-01-01T00:00:00Z De Silva, S. I. S. Bulathgama, B. E. A. U. Somarathna, K. T. A. G. Ranasingha, R.D.A.K. Karunarathna, K.H.T. Rajawatta, K.M.W. Chandana, E.P.S. http://ir.lib.ruh.ac.lk/handle/iruor/21559 2026-08-11T07:32:59Z 2024-01-01T00:00:00Z

Physico-chemical and Consumer Preference Analysis of Novel Herbal Soap Enriched with Aloe vera (Aloe barbadensis) De Silva, S. I. S.; Bulathgama, B. E. A. U.; Somarathna, K. T. A. G.; Ranasingha, R.D.A.K.; Karunarathna, K.H.T.; Rajawatta, K.M.W.; Chandana, E.P.S. Herbal soaps are popular products at a homemade scale worldwide, but innovative and commercialized local formulations are rare. Sri Lanka has a rich herbal diversity, and several plant extracts have been scientifically proven to show bioactivities such as anti-inflammatory, antibacterial, and antifungal properties. An instance of this is a herbal soap formulation that is useful for treating microbiological infections and regular use. The current study aimed to develop a novel herbal soap enriched with extracts of aloe vera (Aloe barbadensis), citronella oil (Cymbopogon nardus) and black tea (Camellia sinensis), evaluate the physico-chemical properties, and gauging consumer preference for the finished prototype while advancing the technology of the current saponification process. The soap base was produced by saponifying coconut oil with NaOH at 40°C, subsequently value added by incorporating 8% aloe vera gel, 4% citronella oil, and 4% black tea extract, and allowed to age for 72 hours at 32°C. The physico chemical properties were determined as follows: density was 0.95 mg/ml, NaOH ratio was 4.16, free alkali content was 0.028% (0.007 mol/dm³), and Total Fatty Matter (TFM) was 79.6%. These metrics comply with the SLS 34:2009 standards and align with previous research findings, thereby classifying the product as Grade 1. Consumer assessment considered colour, aroma, texture, washing quality, and overall acceptability, revealing a brownish-golden hue, pleasant fragrance, a soft, consistent texture and gentle hand impact. Consumer preference was assessed across diverse socio-economic groups, revealing a high overall acceptability rating of 8.65 out of 10. The study advances soap technology, emphasizing compatibility with existing standards and consumer satisfaction.

2024-01-01T00:00:00Z Silva, S.A.P.S. Dahanayaka, A.J.G.S. Rajawatta, K.M.W. http://ir.lib.ruh.ac.lk/handle/iruor/21558 2026-08-11T07:27:11Z 2019-01-01T00:00:00Z

Design consideration of the semi-automated coconut de-husking machine Silva, S.A.P.S.; Dahanayaka, A.J.G.S.; Rajawatta, K.M.W. The process of de-husking which is the most important phase in coconut processing has faced a crisis in Sri Lankan coconut industry due to the scarcity of skilled labor and the complexity in manual de-husking. In an effort to mitigate these issues, this research aims at finding the most suitable design consideration to fabricate an efficient and a semi-automated coconut de-husking machine which will assure the safety while maximizing the rate of productivity. Machine will be designed with two rollers rotating in opposite directions having number of rectangular steel bars connected to the circumference of the rollers in axial direction and top of these two rollers there is a rotating flat rubber belt to press and hold the nut while in the de-husking process. Based on the calculations, required force to separate one part of the husk from the nut was 700 N. The expected capacity of the machine is 1200±50 nuts per hour with 2% of nut breakage.

2019-01-01T00:00:00Z