bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of Modified Crumb rubber Interlocking Paver
Authors: Adeboje A. O. , Modupe A. E. , Fadugba O. G. , Busari A. A.
Published: April 2021

Interlocking pavers, otherwise called paving blocks, brick pavers or concrete paver blocks are produced from bricks or concrete blocks and are used for paving the exteriors of buildings and surfacing of driveways, floors, paths, patios, pool decks and walkways. Interlocking paving units have been successfully used worldwide for the surface of roadways and have adequately carried traffic loads without failure or deterioration. This study investigated the impacts of 2, 4 and 6 % replacement of sand with crumb rubber on the engineering properties of the interlocking pavers in order to produce a sustainable and environmental friendly interlocking paver. For the control sample the mix ratio was 1:1.38: 2.73 for cement, sand and coarse aggregate, respectively. The mixes had a water cement ratio of 0.4. The experiments conducted on cement were chemical composition, standard consistency and setting time. The tests carried out on the aggregates included chemical composition, sieve analysis, humidity content and specific gravity. The test conducted on the interlocking paver blocks were slump, bulk density and compressive strength. The study revealed that the cement had a standard consistency of 25%, initial setting and final setting time of 28 and 246 minutes, respectively. The major oxide compositions of cement were Calcium Oxide (CaO) and Silicon Dioxide (SiO2) with 60.38 and 20.8% constituent, respectively. The fineness modulus of the sand, crumb rubber and granite samples was 2.54, 1.50 and 2.35, respectively. The density and compressive strength decreased at each of the ages of curing (3, 7, 28 and 56 days), as the crumb rubber content in the interlocking pavers increased. Though the mechanical properties of the modified crumb-rubber interlocking pavers reduced, the interlocking pavers can still be used for low trafficked roads and as kerbs on the highway.
Generation of Typical Meteorological Year Data for a City in South-Western Nigeria
Authors: Oyedepo S. O. , Oyebanji J. A. , Ukponu S.N. , Kilanko O. , Babalola P. O. , Fayomi O.S.I. , Dirisu J.O. , Olawole C.O. , Leramo R.O. , Dunmade I.S. , Efemwenkiekie U.K. , Shopeju O.O.
Published: April 2021

Weather data is essential in determination of the performance of energy systems such as HVAC and solar energy systems. Weather data therefore, can be employed in designing more energy-efficient systems. This work focuses on the generation of a Typical Meteorological Year (TMY) Data for Abeokuta (7°7′1″ N, 3°22′13″E), a state in South-Western Nigeria by the use of a modified Sandia method. It makes use of seven weather parameters obtained over 29 years (1984 - 2012) in the construction of the TMY. Sandia method is highly affected by solar radiation even if its weight is reduced by half. The weights of other parameters such as temperature, wind, and relative humidity have less impact on the selection of TMY. The results of this study show that the weather pattern of Abeokuta follows the general diurnal variation of dry/harmattan season and wet/rainy season, typical to Nigeria. In this work also, the effect of general rise in temperature and solar radiation, indicative of global warming, is highlighted. Higher solar radiation values are majorly typical of a low cloud cover, and high clearness index. Suggestions were also made as to the preferable type of sustainable energy system to make use of in this location, as well as in the development of energy systems and data collection in Nigeria. The relevance of this work is that it would help to strengthen building energy standards, understand the local climate of Abeokuta and hence facilitate building energy system performance.
Bio-Agro Waste Valorization and its Sustainability in the Industry: A Review
Authors: Afolalu S. A. , Salawu E.Y. , Ogedengbe T.S. , Joseph O. O. , Okwilagwe Osise , Emetere M. E. , Yusuf O. O , Noiki A.A , Akinlabi S.A
Published: April 2021

The application of bio-agro waste in industrial production has become extensive. Many industries have embarked in large scale production due to the broadness in the application of the bio-agro waste. This study vividly and succinctly surveyed the different bio-agro waste, its areas of application and its sustainability in industrial production. Several examples of bio-agro waste have been reported. Their relevance in bio-ethanol production has equally been discussed. More so, current research and development in harnessing the bio-agro waste were equally reported, to achieve better economic sustainability. Thus, the study has provided a new circular economic method for addressing the problems associated with bio-agro waste.
A review on electrical bulbs and its improvement over time: Saving energy or life?
Authors: Emetere M.E. , Bologi L.P. , Sanni S.E. , Chidi O.R. , Femi-Pidan D. , Okoro E.E.
Published: April 2021

Electric bulb technology evolved over the decades with striking innovations and a corresponding shortcoming. The paper examines the pros and cons of the different bulbs available in the market. It was observed that all bulbs had their unique advantage and disadvantage. However, the review showed that some of the shortcomings can be overcome. Hence, it is possible to relate with either the old and new bulb technology without many environmental hazards and technical errors. It was also observed that the health hazards in the compact fluorescent lamps (CFLs) and light-emitting diodes (LEDs) can be modified to drastically reduce its health hazards. Salient recommendations were made to aid researcher for further work.
Parametric Optimization Route of Oil Extraction from Seed: A Review
Authors: Bitire S.O. , Belaid M. , Imoisili P.E. , Jen T.C.
Published: April 2021

Over the years, oil extracted from seeds has been employed as a skincare product, food, perfumes, biodiesel, soap and so much more. With the advent discovery of biodiesel, reliance on fossil fuels like petro-diesel has reduced drastically, as alternative diesel which burns in engines without the emission of greenhouse gases and less air pollution are being considered. Biodiesel production using seed oil is a means of converting waste to wealth because they are less expensive, biodegradable, and easily accessible. The use of seed oil for the production of alternative renewable energy can be achieved through extraction and the quality and quantity can be increased by the optimization of the process variables adopted for extraction. In this review paper, the different oil extraction method such as the conventional and the recent techniques will be evaluated as well as the downside and benefits of the extraction techniques, experimental designs employed for the optimization of seed oil alongside the impact of desired process variables on the amount and quality of the oil. Several studies have been conducted as regards seed oil extraction by adopting various techniques. However, the choice of a technique suitable for oil extraction with reasonable oil yield and good quality is very paramount and this is ultimately dependent on the type of seed and on whether the oil required is on a small- or large-scale basis. Optimization of process variable for extraction of seed oil will help save cost and improve the quality and quantity of seed oil.
Utilization of Poly (ethylene terephthalate) Waste and Seashell (Senilia senilis) in the Production of Roof Tiles
Authors: Bamigboye G. O. , Oderinde F.O. , Olukanni D.O. , Ngene B.U. , Adeyemi G. A. , Adegoke D. D.
Published: April 2021

Pollution has been a vital issue, especially in developing countries like Nigeria. Polyethylene terephthalate (pet) bottles from its introduction into the economy, has been a major pollutant of the environment, culminating a nuisance to the environment and unsafe habitat to human health. Water channels such as rivers and oceans are not exempted, as marine animals are also at risk of this due to the dumping of waste into our waterways. The utilization of waste pet bottles and seashell in the production of roof tiles will go a long way in the encouragement of proper disposal and management of waste. From this study, a mixture of pet bottles, river sand, and seashells in varying proportions were used to make roofing tiles. The composition with the highest strength is seen to be the P50b, which has 50% pet waste, 25% Senilia senilis, and 25% River sand. It has a smoother surface in comparison with the other compositions and more aesthetically appealing. The product showed more strength when compared with the commonly used asbestos sheets. The production of this roofing sheet will help provide affordable housing production of units, create job opportunities in both production & marketing, reduce importation of raw materials, and improve the economy of the nation.
Correlation of Material Waste Types With Life Cycle Stages in Building Projects Across The States in Southwest Nigeria
Authors: Tongo S. O. , Oluwatayo A.A. , Adeboye A. B.
Published: April 2021

This study correlates the different opinions held by Nigerian construction industry stakeholders who participated in the survey on the types of material wastes that are generated from the activities of procuring building projects across the states in southwest region of Nigeria. This was achieved through the random distribution of 261 questionnaires to build environment professionals recruited in the study. The results from 261 respondents was analysed using SPSS 26.0 and presented using tables, figure, ranking and percentile. The study found that the wastes from building construction activities are primarily physical in nature and perceived to be prominent at the post-construction and construction phases of a building project, however, it is seen to occur across the life cycle stages of a building project in varying proportions that adds up to become significant and critical. Additionally, the study found that paper was the most (31.7% and 39.5%) common form of wastes generated at the pre-design and design stages of a building project., while at the pre-construction stage, cardboard and other package materials (35.1%) were the most common form of waste generated, Also, the study revealed that at the construction stage, wood (80.5%), aluminium (88.55), sandcrete (85.0%), and ceramic (85.5) were mostly the form of waste generated, while at the post-construction stage, wire and cables (19.3%) were the mostly form of waste generated. However, the findings from this study provide a valuable reference for practitioners to develop and adopt strategic guides for managing material wastes on building construction projects across building construction stages that imbibes principle of sustainable construction.
Assessment of Passive Cooling Potentials to Enhance Thermal Comfort in Office Buildings in Dry Sub-Humid Climate
Authors: Kanoma Muhammad Usman , Yahuza Abdulhamid , Yabo Umar Kabir
Published: April 2021

The importance of optimizing thermal comfort in interior spaces through passive means cannot be over-emphasized, especially in tropical regions in order to lower energy demand for cooling and to promote sustainable practices in Sub-Sahara Regions like Nigeria. This paper aimed at assessing the potential of passive cooling potentials in selected Nigerian Universities’ buildings in the North-East sub-region. In this study, quantitative method of data collection was adopted. Three cases were studied such as Administrative Building of Gombe State University (GSU), Senate Building of Abubakar Tafawa Balewa University, Bauchi (ATBU) and Administrative Building of Modibbo Adama University of Technology, Yola (MAUTECH). The results of the study are presented in simple percentages, tables, figures and frequencies in adherence to the checklists derived from Contemporary Methods of Passive Cooling established by Santamouris & Kolokotsa as follows: MAUTECH’s Administrative Building scored 45% while ATBU Senate Building assessed to have 48% and GSU Administrative Building got 55%. This connotes that, designers should embrace passive elements in design and construction of office buildings in Nigeria as two of the three case studies fell below 50%.
Application of Data Logger for Monitoring Indoor and Outdoor Temperature of Buildings: A Review
Authors: Essien V. , Bolu C. A. , Azeta J. , Okokpujie I. P. , Kilanko O. , Afolalu S. A.
Published: April 2021

A great deal of importance is being placed on the building energy management system all across the globe. A particular emphasis is being placed on methods to monitor building performance, the cost of electricity consumption as well as in other cases, the carbon emissions. This paper considers a critical examination of the various works carried out regarding building monitoring instrumentation multiple applications of a data logger. Furthermore, this paper sheds more light on developing a simple data logger to monitor indoor and outdoor temperature.
Preparation of Carbon Brushes from Agro-Waste Materials Palm Kernels Shells for Automobile Industry
Authors: Ugwu S. C. , Inegbenebor A. O. , Fayomi O. S. I. , Udoye N. E.
Published: April 2021

The carbon brush is mainly applied in a rotating shaft as an electrical contact in conducting current between static wires and moving parts. It is applied majorly in electric motors, alternators, and electric. The automobile industry has recently developed rapidly in the world with numerous novel kinds of motors with low power and high speed. The materials that are utilized in the manufacture of carbon brush are copper metal, amorphous carbon, graphite, retort cokes, petroleum coke, binders, lubricants, and some other metal powders serving various purposes. The major part of the carbon brushes is carbon which can be derived from carbonaceous materials such as agro-waste. The agro-waste of palm kernel shell was prepared through pyrolysis using an anaerobic furnace at 500 °C – 800 °C for five hours to obtain carbonaceous material. The carbon which is the main component was activated at this temperature using the physical activation method. The samplers produced contained copper, zinc, and molybdenum disulphide as a lubricant with a resin binder in a different ratio. The samples were characterized by several testing. The results showed that the hardness, bending strength 1125 N/mm2, resistivity 14 μΩcm, and bulk density 1026 g/cm3. These were compared with control samples from the industry which have Brinell hardness 398.22 BHN, bending strength 1305 N/mm2, resistivity 22 μΩcm, and bulk density 1104 g/cm3. From the comparison result, the properties measured of the sample fell within a reasonable range with the industry carbon brush. In conclusion, the result demonstrates that agro-waste such as palm kernel shell is a viable means in the production of carbon brushes for the automobile industry.
Dynamic Simulation of Gear System Based on 2D Space Multibody Physics: A Sustainable Gear Design Approach
Authors: Salawu E. Y. , Ajayi O.O. , Inegbenebor A. O. , Akinlabi Stephen , Afolalu S. A. , Edun B. M.
Published: April 2021

The study employed a two-dimensional (2D) space with multibody dynamics as the physics to simulate the dynamic behaviour of intermeshing gears. Both the gear teeth and the gear body were employed to simulate the principal stress and strain as well as the Von Mises stress of the gear system. A pair of meshing teeth were examined from the pinion and the other from the gear for accurate contact stress-strain simulation. The validity of the proposed gear simulation was verified from principal surface stress, Von Mises stress, principal surface strain, elastic strain and total displacement. The results show that the dynamic behaviour of the gear could be attributed to the critical meshing characteristics of the single and double teeth. The peak-to-peak pattern of the Von Mises stress indicates the essential points of stress, which could cause the occurrence of the failure modes. The research of the gear motion study is profoundly enriched and served as a critical reference for gear design.
Influence of anionic surfactants on the stability of multi-walled carbon nanotubes-based nanofluid
Authors: Borode A.O. , Ahmed N.A. , Olubambi P.A.
Published: April 2021

This study aims to assess the influence of anionic surfactants such as sodium dodecyl sulfate (SDS) and sodium dodecylbenzene sulfonate (SDBS) on the stability of nanofluids of multi-walled carbon nanotube (MWCNT). The influence of different surfactant concentrations on the stability of the nanofluids was also evaluated. The nanofluids were prepared by dispersing MWCNT in deionized water with SDS and SDBS as dispersant at different MWCNT/surfactant ratio, which includes 1:2, 1:1 and 2:1. The stability of the nanofluids was evaluated using zeta potential analysis and ultra-violet visible spectroscopy. The results indicated that SDS and SDBS sufficiently improve the stability of MWCNT in the suspension. Nevertheless, SDBS was found to perform much better than SDS. The optimal MWCNT/surfactant ratio for SDS and SDBS was reported to be 1:1 and 2:1, respectively. This study further confirms that the zeta potential result is consistent with that of the ultra-violet visible spectroscopy.
Modification of Nigerian Bitumen Using Locally Source Materials
Authors: Adeyemi G. A. , Fadairo A.S. , Oladepo A.D. , Ayoola A. , Ilusemiti T. , Oguezuonu S.
Published: April 2021

Bitumen utilized for road construction must satisfy international standard, Nigeria bitumen could not be used because it falls short of the necessary standards approved globally for road construction, it prompts early potholes, rutting, bleeding, hence there is need to modify and improve the properties of Nigeria bitumen. The reason for this study is to upgrade the locally found bitumen in Nigeria to international standard so that the country can curb incessant importation of bitumen for road construction and pavement, as nature naturally endowed the country with bitumen. Several approaches are available by which local bitumen can be modified, but, this paper focused on blending form of modification. Local bitumen (unmodified sample) used for this study was gotten from a village in Ondo state, Nigeria called Agbagu. The bitumen was mixed with powdered (150-micron size) rubber tyres, potash and carboxyl methyl cellulose (CMC) polymer (modified sample). Only 30% by weight of the mixture was used to upgrade 200 grams of the local bitumen sample. Various tests such as penetration value test, softening point test, viscosity test, flash point test and fire point test were carried out on modified bitumen to determine the consistency of the upgraded bitumen. The result confirms that the modified Nigerian bitumen sample when compared with the foreign sample, improved in quality and properties, thereby approaching the international standard required for road construction and other uses of bitumen internationally.
Synthesis of Nanosilica and its application as Water Based Mud Rheology Enhancer
Authors: Okoro E. E. , Gareca N.P. , Uranga L.L. , Sanni S.E. , Emetere M.E. , Orodu O.D.
Published: April 2021

This study synthesized nanosilica from sodium silicate solution using precipitation method for 3:1 ammonia/ethanol ratio, and examines the effectiveness of the nanosilica in formulating high-performance water based mud system. Sodium silicate solution (SSS) is a low-cost precursor than tetraethyl orthosilicate. Three (3) solutions of sodium silicate with concentrations 0.5 N, 1 N and 1.5 N were used to precipitate nanosilica. The use of sodium silicate solution in alkaline medium produces less agglomerated nanosilica. The results gave Similarly, three (3) different samples of silica nanoparticles (Sample A, Sample B, and Sample C) with each concentration respectively. The silica nanoparticles from the Sample A had the smallest in size and quantity, and also the most dispersed. For Sample B, the nanosilica produced was apparently bigger than that of sample A in size and quantity produced. Sample C was produced using two procedures: Sample C1 (with ultra Sonicator) and Sample C2. (ultra Sonicator). Samples C1 and C2 produced the biggest size and quantity of nanosilica with less the dispersion. But, there were aggregation problems, due to the higher concentration of sodium silicate solution. There was no much difference between samples C1 and C2; just that with the former, the nanosilica was better dispersed and the latter was little more aggregated. The precipitated nanosilica, Sample B with 1 N concentration of SSS gave the optimum size and quantity, and was used to formulate the examined high-performance water based mud system. The silica nanoparticles had a positive effect on the drilling fluid systems flow properties. This due to their ultrafine size and high surface area. Also, nanosilica production is cheap and feasible, so it could easily replace other expensive additives.
Drivers of Renewable Energy Adoption in the Built Environment: A Case of South Africa
Authors: Oguntona O.A. , Aigbavboa C.O. , Monnanyana T. , Thwala W.D.
Published: April 2021

The built environment is regarded as the biggest consumer of energy globally due to its energy-intensive characteristics. Despite the over-reliance of both developed and developing nations on fossil fuels, there is a growing demand for energy as the population increases thereby exerting significant pressure on the energy production, generation, transmission and distribution infrastructure. To proffer a lasting solution to the energy challenges, countries are now advancing their quest for alternative energy sources. Hence, the growing clamour and global attention on renewable energy which is also identified as a clean and sustainable solution compared to the traditional fossil fuel-based energy source. This paper is aimed at identifying the drivers of adopting renewable energy in South Africa. Data was gathered through a well-structured questionnaire distributed to relevant construction professionals. A quantitative approach to data analysis was employed using percentages, standard deviation and mean item score. From the analyzed data, the results revealed that training and education of professionals, efficient energy sector reforms, awareness creation, government support, and increased supply of renewable energy technologies are the top five drivers of renewable energy adoption. It is therefore important for the government and relevant stakeholders to encourage and support the integration and adoption of renewable energy owing to its potential in significantly reducing the negative environmental footprint of the built environment.
Construction Digitalisation Tools In South African Construction Industry: An Added Advantage
Authors: Tanga O T , Aigbavboa C O , Akinradewo O I , Thwala D W , Onyia M
Published: April 2021

The execution of the building project requires the assembling and accumulation of works at a large scale for it to become a reality. This involves the exchange of a large amount of data from one party to another. The development of information and communication technology (ICT) has therefore enhanced an active and proficient way of exchanging data among professionals. This research work set out to assess the benefits of using ICT tools by construction organisations in South Africa. A quantitative research technique was used through a well-structured questionnaire to collect data from construction professionals. They include construction project managers, civil engineers, quantity surveyors, construction managers, industrial, mechanical and electrical engineers. Standard deviation (SD) and mean item score (MIS) were used to analyse the retrieved data. The findings indicated that the most eminent benefits of ICT tools to construction organisations are effective communication management, competitive advantage and time-saving. This study recommended that construction organisations should provide lessons on different ICT tools uses to address each problem that will rise during the construction cycle and reap the full benefit of ICT such as improved productivity, increased speed, and diversification.
Controlling virus droplets diffusion in an isolated room using CFD
Authors: Chandra Shekar N.V. , Abhinay B. , Raj Pavan C. , Harish R.
Published: April 2021

This paper presents an isolation room model with a patient carrying acute air born disease with an effective ventilation system being functioned. Different models have been simulated with different vent position and the results have been observed. With the unruly rise in the spread of the COVID-19, it is paramount to restrain the virus propagation within the hospital premises. The purpose of the research is to control the virus dissemination caused by sneezing, by altering the position of the ventilation i.e. air inlet and outlet, by using flow across the room to direct it towards the outlet with maintaining a negative pressure. The negative strain helps in confining the air-borne transmission of the deadly virus from spreading across the room and not letting them permeate outside the isolated region. An isolation room model has been studied using computational fluid dynamics, by setting up a discrete phase model by using injection spray modelling to observe the permeation of the virus droplets. The behaviour of these aerosol droplets are studied using simple-semi implicit method for the equation associated with pressure by specifying the droplet size. By altering inlet and outlet locations we are able to minimise the spread of these harmful droplets by using the flow from the air inlet to go against the diffusing droplets. These paper aides well for a sudden isolation room setup anywhere with peruse dimensions of the inlet and outlet height at most optimum position.
Computational study of Corona Virus diffusion in a closed environment
Authors: Harish S. , Nihaarikha G.N. , Harish R.
Published: April 2021

The biggest challenge that is faced by the human race after World war 2 is the Covid-19, which has affected more than 27.8 million people. The Covid 19 pandemic has entirely changed the livelihood of the people. It is not only seen as a global health crisis but also a Socio-economic issue that has disrupted the Governments worldwide. There is situation where normality is being questioned in the post pandemic era. Many regulations such as Quarantine, self-isolation, social-distancing, and travel restrictions have been advised to prevent the spread of covid-19. After several months of quarantine, the world is now slowly pacing its way back to normality as the vaccine has been invented and brought into use. It is expected that the educational institutions, work places and other public arenas will be opened for the use. However, the regulation of wearing mask and following social distancing are mandatory in public places. Considering the above situation as a need of the hour, this article mainly focuses on the Computational study of the Corona Virus diffusion for a confined space such that it can be applied to places with high population mass. The numerical model was simulated using ANSYS fluent and the results obtained are in excellent accordance with the literature.
Analyzing social distancing policy effectiveness using Computational Fluid Dynamics inside a bus to prevent COVID-19 airborne transmission
Authors: Pavansai A. , Deepak P. , Ragul Hari S. , Harish R. , Shyam Kumar M.B.
Published: April 2021

Coronavirus disease (COVID-19) is a kind of disease that transmits from one body to another through air by the moist particles caused during sneezing and coughing. As a result, to reduce the virus spreading accordingly, 1.83 m of social distancing has been advised to be followed among the humans. Also, it is not well studied that whether the ambient wind and relative humidity (RH) will cause COVID-19 laden cough droplets to transport farther in the air, and make the current social distancing practice ineffective. In this study, computational fluid dynamics simulations are carried out to analyze the transient transport, condensation/evaporation, and deposition of COVID laden droplets emitted by coughs, with the different environmental conditions, cough velocities and Relative Humidity using the developed bus model of size 12 m x 3.5 m x 3.2 m. Different conditions of sneezing and coughing from the human’s i.e., the laminar and the turbulent flows of the laden droplets in the air inside the bus were also examined. The distance between the two virtual humans is set as 6 m for a 12 m bus length in order to track the distance covered by cough particles. The facial covering effect on reducing the airborne transmission of the cough droplets has also been evaluated. It is found that due to the ambient air and humidity, the generation of secondary laden droplets occur which travels far and accumulates on the ground or any other third human being around and causes a strong potential risk to their health. The secondary droplets are transforming into large droplets due to high humidity and the hygroscopic effect is evaluated. The 6 feet social distancing is found to be ineffective for halting the spread of viruses among human beings because the micro-laden droplets caused during the sneezing and coughing are influenced by the convection effects and transport from one body to another within 5 s. It is thus recommended to wear masks for both infected and healthy humans to reduce the airborne cough droplets.
Rupture Mechanism of Cerebral Carotid Aneurysm Using Computational Methods
Authors: Sawant Vrushabh , Chaudhari Rohit , Sreeja V , Eienstein Albert , Jebaseelan Davidson , Jebaraj C
Published: April 2021

This study helps to predict the rupture mechanism of an Inter Carotid Artery (ICA) for saccular aneurysm study through the Finite Element Method (FEM) combined with Discrete Element Method (DEM) of LS DYNA and also compared with a Fluid Solid Interaction (FSI) study. Also the thickness of an artery wall was found by using James-Guth Stress Strain Relation with validation. It was concluded that the Finite Element Method with Discrete Element Method was more efficient than FSI as the computation time was reduced by 51.55% with an error of 0.08%.
Numerical analysis of hat stiffened composite panels for pre and post buckling conditions
Authors: Ram Murthy V , Annamalai K , Elango M
Published: April 2021

This research aims in studying the pre-buckling and post-buckling behaviour of composite panels stiffened by hat stiffeners under compressive loading. Stiffened panels are used in aerospace, marine and also in bridge structures. They are used to make the plate girders stiff. By using composite materials, the strength can be increased, and the weight can be reduced. In Composite panels which are stiffened, local buckling and failure of panel happens because of the applied compressive loads and due to combination of compressive and shear loads. The Collapse of the stiffened composite structure starts from the intersection between the plate and the stiffeners due to stress effect caused by deformation of lamina skin and stiffeners then leads to the structural buckling of skin of the panel. This research uses nonlinear Finite element approach to investigate the collapsing behavior using ABAQUS software.
Study on performance of various stent materials using explicit finite element analysis
Authors: Mane Ajinkya R , Davidson Jebaseelan D
Published: April 2021

In many countries, cardiovascular disease is the main cause of mortality. Stent is tiny wire mesh tube which is inserted in coronary artery to get rid of blockage. Stents are available in various types Bare metallic, Drug eluting and Bioresorbable. The use of bioresorbable stents reduces the threat of post-implantation effects like stent thrombosis and bleeding, it also dissolves in the body over the period of time once the healing is done while re-narrowing of the artery is more likely to occur in bare metal stents. Metals are important materials for stent due to mechanical properties and ease for Image processing. The objective of the work makes an effort to compare various materials used in stent using explicit analysis. For analysis, we used AISI 316L stainless steel, Nitinol and Mg alloy (WE43) which are standard materials for stent application. Explicit finite element study was done to study the performance of stent at varying pressures from 100 to 120mm of Hg, which is normal blood pressure range of a human body. This computational study found that Nitinol has stress values from 2.18MPa-2.62MPa and was less compared to other materials. Further study are planned to study the impact of coating that can enhance the biocompatibility.
Three-Dimensional (3D) printing and bioprinting for orthopaedic biomaterials - A short review
Authors: Sughanthy Siva A.P , Ansari M.N.M , Nordin Noor Afeefah , Hwei Ng Min
Published: April 2021

Tissue engineering is a non-conventional approach in creating artificial organs and tissues to heal from bone fracture or organs malfunction by regenerating the damaged tissues. This review paper focuses on bone scaffold fabrication methods using three-dimensional (3D) printing and bioprinting for tissue engineering applications. Various types of biomaterials and fabrication techniques of bone scaffolds aimed for tissue engineering were thoroughly discussed. Suitability of biomaterial and polymer for bone scaffolds is deliberated as part of the review paper. Several biomaterials, mechanical properties and porosity of scaffolds were reviewed to give an in depth understanding on 3D printing and tissue engineering field.
Numerical Investigations into the Effect of Confinement on the Stability of an Oscillating Planar Liquid Jet
Authors: Arote Ashish , Bade Mukund , Banerjee Jyotirmay
Published: April 2021

The liquid jet under certain conditions when perturbed will lead to instability. The understanding about an effect of confinement on these jets is still obscure. Hence, numerical investigations are reported in the present study for two phase spatially oscillating planar jet in a quiescent air under the confined conditions. Simulations are performed by solving the Navier-Stokes equations using volume of fluid (VOF) method to track the air-water interface. In the present study an oscillating jet is subjected to various confinement ratios (CR) to understand the jet behaviour under such conditions. It is demonstrated that the amplitude of oscillation increases as the confinement ratio decreases. This behaviour is a result of increased intensity of vortex rotation at each jet peaks as the confinement ratio increases. Moreover, it is also demonstrated that the vortex structure interact with the side-walls and disturb the incoming flow causing non-linear growth of oscillations leading to primary breakup in these jets.
Computation of a Compartment Fire with Smagorinsky Sub-Grid Scale Model
Authors: Dhurandher Bhisham K , Kumar R , Dhiman A K , Dubba Santhosh K
Published: April 2021

A fire tests using plywood crib as fire source was done in a cubical compartment to investigate the fire development and temperature distribution. The dimension of the experimental compartment was 4 m high, 4 m wide and 4 m length with a door opening of 2 m × 1 m wide located at one of the compartment wall. Several parameters were measured which includes fuel mass loss rate, compartment gas temperature, centerline doorway temperature, heat flux and wall surface temperature. Three-dimensional numerical simulations were performed using large eddy simulation with different values of Smagorinsky sub-grid scale constant. In order to accurately investigate the behavior of fire within the compartment by computational fluid dynamics (CFD), it is vital to study these Smagorinsky sub-grid scale constant. Numerically predicted results with various Smagorinsky sub-grid scale constant was compared with the physical results. It was found that the varying the Smagorinsky constant affect the numerical simulation results.
Thermodynamic Assessment of a Gas Turbine System Combined with A Solid Oxide Fuel Cell Powered by Synthetic Gas from Municipal Solid Waste
Authors: Venkitesh K.S , Daniel Joseph , Sreekanth Manavalla
Published: April 2021

In this work, a detailed thermodynamic analysis is performed on a solid oxide fuel cell-gas turbine combined system. The fuel input to the fuel cell is the synthetic gas produced from the gasification of municipal solid waste. The efficiency and output power of the system are calculated and the system is analyzed for its performance by variation of parameters which includes compression ratio, fuel utilization factor and current density. The work is done based on the Municipal solid waste generated in Indian cities. Destruction of exergy is calculated from exergy analysis. System is modelled using flow sheeting program Cycle Tempo®. Components contributing to major exergy destruction are combustor and fuel cell. Energy efficiency of 44.5%, exergy efficiency of 39.2% and a power output of 170 kW is obtained in this system. This CHP system is very much acceptable for restaurants, shopping complex and other small-scale applications where power requirement is less.
Design and Vibration Analysis of Pump Assembly for Two Types of Cushy Mount
Authors: Mounika CH , Annamalai K , Vinoth kumar S , Ponraj A
Published: April 2021

This paper is mainly focused on vibration characteristics of pump motor assembly and selecting suitable mount for the assembly using FEA and experimental approach. Pump motor assembly is connected to base structure by mount. Modal and FRF Analysis are performed to study the mode patterns, natural frequencies and vibration response of the entire structure. Experimental study helps to evaluate the vibration amplitude values of the structure. FFT analyser is used to measure the RMS acceleration of the entire assembly, BK (Bruel & kjaer) Connect software is used to extract the data from FFT analyser. Comparison study reveals and evaluates the vibration characteristics of two mounts and the best mount is suggested. The first section in your paper.
Processing of exposure results for composite material with the choice of their optimal composition
Authors: Bulgakov A , Afonin V , Erofeeva I , Fedortsov V
Published: April 2021

The article presents the results of processing a number of compositions of composite materials sustained under cyclic temperature changes, as well as changes in humidity and positive temperatures. A method is proposed for determining the optimal composition of materials, taking into account changes in such characteristics as hardness, modulus of deformation of the material and the elastic modulus of the material during exposure.
A review of flash floods in the Dobrogea Region
Authors: Buzgaru N , Maftei C
Published: April 2021

The last decade is characterized by an increase in the occurrence of flash floods, fact which is confirmed by the worldwide endeavors undertaken by the WMO (World Meteorological Association) which initiated the signing of a series of memorandums for collaboration with other worldwide institutions meant to lead to the elaboration and implementing of a complex flash flood warning system. The aim of this paper is to analyze the level of implementation of said system in Europe and Romania and the analysis of the flash flood occurrence, specifically in the Dobrogea region of Romania.
Insights from the management of a large research infrastructure in Romania: National Network for the Seismic Monitoring and Protection of Building Stock at NIRD URBAN-INCERC
Authors: Dragomir C S , Craifaleanu I G , Meiţă V , Georgescu E S , Dobre D , Sandu M , Cişmelaru A
Published: April 2021

The National Network for the Seismic Monitoring and Protection of Building Stock is a key infrastructure of the National Institute for Research and Development in Construction, Urban Planning and Sustainable Spatial Development "URBAN-INCERC" in Romania. This infrastructure includes at present, among other research facilities, a strong-motion network of 64 permanent seismic stations, to which other temporary stations are added for various short-term vibration monitoring projects. Since its establishment in 1967, the seismic network has played an essential role in recording the earthquakes that affect Romania. Today, the seismic stations are distributed all over the country, according to its characteristic seismicity patterns. Most of them use state-of-the-art recording and communication equipment, being permanently connected online to the Data Center in Bucharest. The management of the network implies conducting a complex set of activities, centered on the recording, processing, analysis and interpretation of natural- and human-induced vibrations. All of these are seconded, in parallel, by various maintenance, reporting, logging, communication and dissemination tasks. The logistic and financial management also plays an important role. A rational and efficient administration of the seismic network cannot be acquired without a rigorous organization of data flows pertaining to the various activities performed. The paper provides insights from the organization of the network, highlighting the intercorrelation between the hierarchical levels of its functionality and the logical course of operation. A brief review of the challenges and solutions gradually developed and implemented by the members of the network team, in order to provide the required functionality, is presented.
Calculation of disc friction power in pumps at operation on viscoelastic fluids
Authors: Morozov V , Morozov A
Published: April 2021

The flow of viscoelastic fluid in the gap between the impeller disc and the pump wall for laminar flow mode is considered. Waste water sludge (WWS) was used as a working fluid. Its flow is described by viscoplastic fluid model. The results of theoretical and experimental studies of disk friction at WWS are presented and formulas are proposed for calculation of disk friction power between wheel disks and pump body.
Using energy of compressed natural gas as an environmentally safe source of heat energy of the heating system of the industrial premises
Authors: Pakhomova E , Grigorova N , Monastyrev P , Semicheva N
Published: April 2021

The housing and utilities system is extremely energy-intensive and currently impedes the implementation of energy efficiency policies. In this regard, the development of science-based technology for environmentally friendly resource-saving consumption of compressed natural gas, as a source of thermal energy, is becoming relevant. The article describes the technical solution for using the energy of compressed natural gas as a source of thermal energy, which consists in using a vortex heat exchanger in the heating system of a gas control station, which allows you to generate thermal energy due to technologically unused energy, which is the pressure drop between high and medium gas pipelines as well as medium and low pressure natural gas. This technical solution is aimed at reducing energy costs and ensuring environmental safety when using compressed natural gas as a source of thermal energy. To determine the possibility of practical use of this technical solution in the production room for installing gas control equipment, an analytical expression of the temperature of the wet gas mixture after the process of condensate-evaporative heat and mass transfer in a vortex heat exchanger has been obtained, which allows us to predict the parameters of the coolant in the heating system of the production room.
Modelling the structure of Carol I Mosque Minaret taken into account the seismic evaluation
Authors: Suliman S , Gramescu A M , Gelmambet S
Published: April 2021

The paper aims to analyze the behavior of seismic actions of minaret – structural components characteristic of mosque. As it is known, the characteristics of this construction are governed by the slenderness and the distribution of the constituent materials by height. An important component is the most real quantification of the characteristics resistances as well as the impact of other loads in operation. The paper presents the case study – the minaret of the Carol I Mosque from Constanta, an emblematic historical monument of Constanta made by Eng. Gogu Constantinescu 110 years ago.
Estimation of energy consumption during cross-flow membrane filtration of oil/water emulsion
Authors: Barambu N U , Bilad M R , Nordin N A H , Bustam M A
Published: April 2021

Abstracts: Pressure driven membrane filtration has been widely adopted for oil and water recovery from oil/water emulsion. The technology offers numerous economic and environmental advantages. However, specific energy consumption remains a critical factor for its economic assessment. The specific energy consumption depends on several factors, among which is the fouling filtration period/time. Therefore, the fouling filtration time indirectly affects the overall economic viability of the system. Herein, the effect of fouling filtration time on the specific energy consumption during cross-flow filtration of 1000 ppm oil/water emulsion was evaluated. During the first 20 min of oil/water emulsion filtration, the energy consumption was found to be 0.0225 KWh/m3. While the filtration was continued to 90 min, the system requires 0.0301 KWh/m3 energy input. The tradeoff between fouling filtration time and energy consumption was found to be just before 30 mins. Suggesting that at 30 mins fouling filtration time, clean water flushing/backwashing would restore significant hydraulic performance and thus, less increase in energy input would be required. At the tradeoff point 0.0254 KWh/m3 energy was required to drive the filtration. This represents up to ∼19 % energy saving compared to the straight nonstop 90 min fouling filtration time. The overall results demonstrated that fouling filtration time affects the overall economics of cross-flow membrane filtration.
Evolution of Photobioreactors: A Review based on Microalgal Perspective
Authors: Ahmad Imran , Abdullah Norhayati , Koji Iwamoto , Yuzir Ali , Eva Muhammad Shaza
Published: April 2021

Energy is indispensable for bringing competence, resilience, and comfort for the ever-advancing human lifestyle. Therefore, to satisfy the growing energy requirement researchers are trying to delve in exploring sustainable and renewable energy sources that will contribute to the reduction of carbon footprint and ultimately help to check the issue of global warming caused by the increased emission of CO2, due to the excessive usage of non-renewable and exhaustive fossil fuels. Microalgae are having the potential which can be exploited to produce biofuels (substitute for fossil fuels) and other value-added compounds. Microalgae is a form of unicellular photoautotrophic microorganism which can attain higher rate of proliferation. Microalgae is having merits over other terrestrial crops and fossil fuels as they have higher productivity of oil per hectare of land. Various other advantages of microalgae include their tolerance in different types of environment because of their ubiquitous nature (in terms of pH, salinity, and temperature). Furthermore, they can be cultivated in nonarable land and wastewater which will resolve the food-fuel duel and problem of freshwater usage, therefore leading towards environmental sustainability. The main factors governing the growth and cultivation of microalgae are light, CO2/air, nutrients, process parameters (pH, temperature, growth medium etc) and most importantly the type of system used for cultivation. The systems usually employed for the cultivation of microalgae are open system (open ponds, raceway ponds, scrubbers), closed system also commonly known as photobioreactors (flat plate and tubular photobioreactors) and hybrid system in which separation of biomass growth and lipid accumulation is achieved in two stages. All the systems have some merits and demerits but photobioreactors are widely accepted and used because they are having an upper hand over open system because of the optimised control of the growth conditions, contamination evasion and efficient productivity of microalgal biomass. This review will provide an insight to different parameters which govern the growth of microalgae and various types of photobioreactors with their advantages and disadvantages. This study will help in the optimized selection of the photobioreactors for a particular species of microalgae because despite the continuous and intensive research going on the cultivation systems it is a challenge for the researchers to achieve a suitable and economically viable system.