Structure – Property relationships for nanofluids

This paper was presented at the 3rd Micro and Nano Flows Conference (MNF2011), which was held at the Makedonia Palace Hotel, Thessaloniki in Greece. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, Aristotle University of Thessaloniki, University of Thessaly, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute.Nanofluids refer to dilute liquid suspensions of nanoparticles in commonly used heat transfer liquids. They triggered much excitement since mid 1990s mainly owing to the claims of anomalous enhancement of thermal conductivity even at very low nanoparticle concentrations. There have been numerous attempts to interpret the mechanism(s) that drive the displayed enhancement. A long debate within the research community supported by experimental and theoretical evidence has highlighted the nanoparticle structuring as the dominant underlying mechanism. On the other hand the viscosity increase as a result of nanoparticle structuring raises concerns about their suitability for certain applications. This paper mainly discusses the structure – property relationship for nanofluids in microscopically static conditions

Development of an Integrated Framework using Machine Learning and TOPSIS for Sustainable Supplier Selection in Circular Supply Chain Management

Sustainable supplier selection is an imperative part in the process where traditional supply chains are transforming into circular supply chains (CSCs) with emphasis on sustainability, resource efficiency, and minimal waste. The supplier selection methods which are traditional are often based on expert opinions and static evaluation frameworks which might be inappropriate to handle dynamic and intricate supply chain environments such as CSCs. In this research, this challenge is addressed by integrating Machine Learning (ML) with the TOPSIS to select sustainable suppliers in the circular supply chain management (CSCM). The ML technique, Random Forest, is utilized in the proposed method to perform feature importance analysis. The various selection criteria are given weights based on the feature importance to minimize bias and enhance accuracy. Suppliers are then evaluated and ranked based on the weights given. The evaluation is based on adherence to the circular economy principles and criteria such as cost, delivery performance and quality which are traditional. To validate the proposed integrated framework, a case study on a food and beverage manufacturing industry was conducted. Data was collected, including primary data obtained through an online structured questionnaire and secondary data from the company’s historical supplier records. The primary data questionnaires were completed by 22 industry experts of the case company. The secondary data was followed by preprocessing, where data was merged and cleaned, the data was then input into the ML Model to derive values of feature importance. These values were next applied in the ML-TOPSIS model to rank suppliers. An analysis between the ML-integrated TOPSIS and traditional TOPSIS methods was conducted to identify the effectiveness of the proposed framework. Findings indicate the objective, adaptive, data-driven decision-making nature of the ML-integrated TOPSIS model. This model dynamically adjusts supplier rankings based on historical data, improving accuracy and efficiency, unlike in traditional TOPSIS, which is heavily based on static, expert-defined weights and longer processing times. This study addresses the literature gap between the ML techniques and Multi-criteria Decision Making (MCDM) methods in selecting sustainable suppliers for circular supply chains. The study provides a systematic tool for industry participants to improve the supplier selection process and promote global sustainable supply chain management. However, the study is limited by the size and scope of the dataset, which may affect generalizability across industries and regions. Future research can address these limitations by expanding datasets, incorporating diverse industry contexts, and exploring advanced ML techniques to improve decision accuracy and applicability

Complexes of N, N- and N, N, N- Sulfonamide Ligands as Therapeutic and Diagnostic Agents

Ethylenediamine, diethylenetriamine and dipicolylamine have been used as the carrier ligands to synthesize bidentate (N,N) or tridentate (N,N,N) chelate systems that coordinate with metal centers. The terminal amine groups of ethylenediamine and diethylenetriamine and the central amine group of dipicolylamine can be easily substituted to give sulfonamide ligands having bulky aromatic fragments. In the formation of metal sulfonamides, the sulfonamide nitrogens of primary or secondary sulfonamidesdeprotonate and coordinate with metal centers forming M-N bonds while the free amines coordinate to metal centers through lone pairs. The reported synthetic approaches and the properties of these complexes and ligands are discussed in this review. The bulky sulfonamide moieties bring about unique biological features to the ligand system while enhancing the fluorescent properties of the ligand. The metal center itself incorporates interesting biological features to the complex. These properties of the metal center andthe ligand show a synergistic effect in the complexes that may come in handy when designing therapeutic or diagnostic agents. The increased lipophilicity of the ligands and thereby the complexes will ensure better uptake by target cells making them ideal candidates for biological applications. Keywords: Sulfonamide, ethylenediamine, diethylenetriamine, dipicolylamin

TRADITIONAL ECOLOGICAL KNOWLEDGE IN AGRICULTURE FOR ADAPTATION/ RESILIENCE TO CLIMATE CHANGE: HIGH MOUNTAIN ASIA

Mountain agricultural systems in the Hindu Kush Himalaya (HKH) are in a unique position to contribute to promoting nature-based solutions in adaptation and resilience to climate change since they are least impacted by the influence of commercial high-production agriculture. This study aims to explore currently available literature for evidence of Traditional Ecological Knowledge (TEK) based agriculture in the HKH region and analyse their contribution to region and location specific climate change adaptation. This is achieved by collection of TEK-based agricultural practices through a systematic literature survey and analysis of their contribution to climate change adaptation through the visualization of the distribution of TEK practices against potential climate change-related hazards for the region and evaluating them against climate adaptation priorities set by HKH countries. The results show that there is a multitude of TEK-based agricultural practices in the HKH region, the most common of which include indigenous soil and fertility management, agroforestry and traditional mechanisms of responding to agroecological shocks. The results also show that these TEK practices can directly contribute towards achieving climate change adaptation priorities of the HKH states. The highest contribution from the available records of TEK-based agriculture is towards the adaptation priorities of developing water and nutrient-efficient crop cultivation systems and improving soil organic matter. The study concludes that TEK-based agricultural practices are indeed significant contributors to climate change adaptation and resilience, except for when traditional practices are deformed due to multiple external stressors that could rather render them climate change aggravators. The study emphasises the need to conserve indigenous lands and indigenous ways of life in order to ensure sustainability of TEKbased agriculture and calls upon the integration of TEK in regional and local adaptation frameworks for climate change adaptation in HKH

Economic Feasibility of Reverse Osmosis (RO) Water Treatment Plants: A Case Study from Dimbulagala, Polonnaruwa, Sri Lanka

Social wellbeing is strongly linked with economic feasibility when it needs to attain with the technological advancements. Installation of Reverse Osmosis (RO) water treatment plants have been considered as a promising solution to provide clean water for human consumption, especially in the areas where the CKDu (chronic kidney disease of unknown etiology) prevails. At present, over 2,000 RO treatment plants were installed in the dry zone of Sri Lanka, yet economic feasibility for operation and maintenance of RO plants has not been assessed so far. The present study was intended to identify economic feasibility of operation and maintenance of RO plants. Investigations were carried out in six community RO plants which provided drinking water for over 17,000 people which accounts for 20% of total population in Dimbulagala Divisional Secretariat over a period of 12 months. Six in-depth interviews and questionnaire survey were caried out with RO plant operators. The operational cost per production of cubic meter of filtered water was computed by considering electricity consumption bills. The maintenance costs and service charges were also obtained from the records available with RO plant operators. The results found that the average electricity consumption to produce 1 cube of filtered water is approximately 9kWh and cost is LKR 734 (based on 2021 rates). The average water selling price ranged between LKR 1.00-2.50 per liter. The average monthly income generation from one RO plant is approximately between LKR 561- 875 per cube of filtered water and it largely depended on the type of water source, climatic conditions. It was found that the income generated from RO plants was sufficient enough to cover the operation cost (monthly electricity bill) and for the subsequent maintenance and service charges whenever required. It can be concluded that the use of RO treated water is an economically viable option to provide portable drinking water.  Keywords: CKDu, Economic sustainability, Drinking water, Purification cos

Green Building Rating of High-Rise Buildings in Sri Lanka

As a result of urbanization, constructions of high-rise buildings become a major component of urban development. Constructing high-rise buildings contributes to social, economic and environmental development as well. There are many stages of construction including planning, designing, procurement and implementation. There is a wide range of sustainability practices which can be implemented in each stage of construction. In leading Sri Lanka to Sustainable Development, the green building rating system was introduced by National Green Building Council of Sri Lanka in 2002. This rating system has 100 total points and minimum of 40 points is required for green building certification. The rating system has different components. Among them sustainable sites category includes 25% of total points in green building rating system. This research study highlights the significance of sustainable sites category in order to award the green certification in green building rating system. For this research five major high-rise building construction sites in Colombo were selected and existing site selection practices of each site were investigated. Each site was visited and in-depth discussions were carried out with the planning engineer and other people in the construction site. The structured questionnaire was filled and scores were given accordingly where they have met the sustainable sites criteria. Two sites out of five could not earn single point as they did not fulfill the prerequisites of the site section category. The rest of the sites (three) earned 20, 19, and 18 respectively out of 25 points. In this study, lack of awareness in sustainable site selection practices has dropped the chances of being eligible for the green building certification. Since the minimum points required for green building certification is 40, buildings which are under planning or pre-construction stage have higher chances of obtaining silver, gold and platinum awards for green building certification. Therefore, sustainable sites category of the green building rating system contributes significantly to increase the score and therefore it is highly important in green certification & sustainable construction. Keywords: Green concept, High-rise buildings, Sustainable development, Sustainable site selectio

Development of Cosmic Ray Simulation Program -- Earth Cosmic Ray Shower (ECRS)

ECRS is a program for the detailed simulation of extensive air shower initiated by high energy cosmic ray particles. In this dissertation work, a Geant4 based ECRS simulation was designed and developed to study secondary cosmic ray particle showers in the full range of Earth\u27s atmosphere. A proper atmospheric air density and geomagnetic field are implemented in order to correctly simulate the charged particles interactions in the Earth\u27s atmosphere. The initial simulation was done for the Atlanta (33.460 N , 84.250 W) region. Four different types of primary proton energies (109, 1010, 1011 and 1012 eV) were considered to determine the secondary particle distribution at the Earth\u27s surface. The geomagnetic field and atmospheric air density have considerable effects on the muon particle distribution at the Earth\u27s surface. The muon charge ratio at the Earth\u27s surface was studied with ECRS simulation for two different geomagnetic locations: Atlanta, Georgia, USA and Lynn Lake, Manitoba, Canada. The simulation results are shown in excellent agreement with the data from NMSU-WIZARD/CAPRICE and BESS experiments at Lynn Lake. At low momentum, ground level muon charge ratios show latitude dependent geomagnetic effects for both Atlanta and Lynn Lake from the simulation. The simulated charge ratio is 1.20 ± 0.05 (without geomagnetic field), 1.12 ± 0.05 (with geomagnetic field) for Atlanta and 1.22 ± 0.04 (with geomagnetic field) for Lynn Lake. These types of studies are very important for analyzing secondary cosmic ray muon flux distribution at the Earth\u27s surface and can be used to study the atmospheric neutrino oscillations

Bubble nucleation on nano- to micro-size cavities and posts: An experimental validation of classical theory

Recently reported data suggest that bubble nucleation on surfaces with nano-sized features (cavities and posts) may occur close to the thermodynamic saturation temperature. However, according to the traditional theory of heterogeneous bubble nucleation, such low nucleation temperatures are possible only for surfaces with micro-scale cavities. Motivated by this apparent contradiction, we have used infrared thermometry to measure the nucleation temperature of water on custom-fabricated nano- to micro-scale cavities (from 90 nm to 4.5 μm in diameter) and posts (from 60 nm to 5 μm in diameter), machined on ultra-smooth and clean silicon wafers using electron beam lithography. Our cavity data are in agreement with the predictions of the Young-Laplace equation, thus re-affirming the correctness of the classic view of heterogeneous bubble nucleation, at least for the water-silicon system investigated here. The data also suggest that individual posts of any size have an insignificant effect on bubble nucleation, as expected from theory.MIT Energy Initiative (Seed Fund Program