bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental Analysis of Evaporative Cooling Water in Porous Clay Vessels Under Varying Ambient Conditions
Authors: Oyedepo S.O , Fayomi O.S.I , Dirisu J.O , Efemwenkiekiea U.K , Arhagba A
Published: April 2021

Due to the ability of clay vessels to store and retain water below ambient temperature, it has become a basic commodity for water storage among the rural dwellers in the Sub-Sahara region and as an alternative to other cooling/refrigerating system. It therefore, becomes necessary to study and determine how effective and efficient porous clay pot serves as evaporating coolers. Evaporative cooling of water in six different porous clay vessels was studied under varying ambient conditions. In this study, water was stored in six porous clay vessels of different sizes and volumes. The weight, relative humidity, and ambient temperatures of water content in the porous clay vessels were measured bihourly from 12 noon to 8 pm for a period of 7 days. The result of the study revealed that the mass loss is affected by several factors such as ambient temperature, the surface area of the vessel, porosity and thickness of the vessel. From this study, pots with small water holding capacity (Pots D and E) experienced the fastest rate of evaporation. The relative humidity was based on the condition of the environment. This study concludes that energy demand can be minimized by applying evaporative cooling concept in households, offices, and industries. Thus, this paper provides an insight towards ways of conserving energy demand for cooling as there is no requirement of electricity to run the system. Hence, extensive usage of these sorts of cooling systems helps in providing greener environment.
Aerosol-assisted chemical vapour deposition synthesis of fluorine-doped tin oxide (FTO) for dye-sensitized dollar cells (DSSCs): Effect of doping with fluorine
Authors: Ikpesu J.E. , Iyuke S. E. , Daramola M.O. , Okewale O.A.
Published: April 2021

In this study, investigation of influence of fluorine doping on conductivity of transparent conducting tin oxide (SnO2) for dye-sensitized solar cells (DSSCs) was carried out. Tin Oxide (SnO2) doped with different percentage of fluorine was deposited by the Aerosol Assisted Chemical Vapour Deposition on the substrate layers of transparent glass slide. Effect of wavelength on the optical properties, and also characterization of the substrate layers was investigated. The results obtained from the UV-VIS spectra indicated that fluorine was successfully doped on the substrate. The doped SnO2 was found to have a lower absorbance when compared to the un-doped one. Transmittance obtained shows that as the wavelength increased, better transmittance was obtained; for instance above 80% for 12% doped F:SnO2, but at lower wavelength of 230 nm. The highest optimum transmittance of 50% was obtained for 4% doped F:SnO2. The thickness of SnO2 nanoparticles was 150 nm for the un-doped; 200 nm for the 4% doped SnO2; 50 nm for the 8% doped SnO2; and 40 nm for the 12% doped SnO2. The conductivity and mobility were 2.426 (Ωcm)-1 and 1.347 cm2/vs for un-doped; 5.039 (Ωcm)-1 and 11.40 cm2/vs for 4% doped SnO2; 20.85 (Ωcm)-1 and 7.457 cm2/vs for 8% doped SnO2; and 1.596 (Ωcm)-1 and 7.457 cm2/vs for 12% doped SnO2. Conclusively, it is evident that FTO is greatly affected by the wavelength as well as the percentage of doping. In case of thin films, conductivity will also depend upon the film thickness. If the thickness is too large beyond an optimum limit, conductivity decreases because grain size of nanoparticle will increase leading to an increase in bandgap (quantum confinement effect).
Corrosion Performance of AA6061/Rice Husk Ash Composite for Engineering Application
Authors: Udoye N. E. , Nnamba O. J. , Fayomi O. S. I. , Inegbenebor A. O.
Published: April 2021

The major problem confronting aluminium alloy in various fields of engineering is based on the structural and continual failure of a component in service. The difficulties encountered are resolved through addition of RHA as strengthening agent to the aluminium metal matrix composite. The fabrication of MMC (AA6061/RHA) using metallurgical stir casting route in the array of 2, 4, 6 and 8 wt. % of RHA was done. Polarization test carried out in 0.75 M of H2SO4 on the composite shows enhanced corrosion susceptibility. Mechanical properties such as microhardness and tensile were performed on the developed composite. Corrosion analysis of RHA embedded in AA6061 revealed improved corrosion performance. Furthermore, the microstructural change through SEM shows that the incorporation of RHA in AA6061 aluminium alloy minimize corrosion effects. It also shows the homogenous dispersal of the fortification along the grain boundaries and reduced fracture propagation.
Physico-Mechanical Properties of Particle Board made from Coconut Shell, Coconut Husk and Palm Kernel Shell
Authors: Atoyebi O. D. , Aladegboye O. J. , Fatoki F. O.
Published: April 2021

This research involves the production of particle boards made from coconut shell, palm kernel shell and coconut husk in different ratios varying from 25%, 30%, 35%, 40% and 50%. These materials were homogeneously mixed with Urea Formaldehyde resin which was the adhesive used commonly known as Top Bond. The physical and mechanical characteristics of produced particle boards which were density, water absorption, thickness swelling, modulus of rupture and modulus of elasticity were analysed. The densities ranged between 995kg/m3 and 600kg/m3. The particle board which had 50% coconut shell, 25% palm kernel shell and 25% coconut husk (E1) had the least value for water absorption after 2hours and 24 hours which was 17.26 and 26.19 respectively. The mean values for Modulus of Rupture and Modulus of Elasticity varied from 0.650N/mm2 to 3.149N/mm2 and 11.659N/mm2 to 146.850N/mm2. It was observed that the particle board which had the most preferable properties both physical and mechanical properties was E1 which was composed of 50% coconut shell, 25% palm kernel shell and 25% coconut husk.
Sustainability of Garri Processing: A Case Study of Ogun State, Nigeria
Authors: Samuel A U , Akinlabi E T , Okokpujie I. P. , Fayomi O.S.I.
Published: April 2021

Garri is one of the most developed and convenient staple food commodities been produced from cassava in West Africa. To select the best method, garri production technology has been produced at different levels, this includes grating, fermentation, and dewatering. Producer of garri and edible starch is faced with the problem of the product price, limited information, and inadequate capital, lack of equipment, poor road, inadequate labour and water supply, long waiting time during grating, and some stages of processing. Limitation experienced by cassava processor includes lack of capital, inadequate power supply, the short lifespan of raw cassava tuber, long fermentation process, high cost of transportation, unstable price of garri. Result obtained from the constraints limiting garri processing in owode-yewa of Ogun state revealed that the short life span of raw cassava tubers is the most severe with 98%. This rating was followed by the unstable price of garri with 92%, long fermentation process with 67%, high transportation cost of inputs with 63%, while the lowest is the lack of access to information with an 8% plant layout. This study was able to provide scheduling operation of garri processing, the process of operation, maintenance of operation, plant layout, and come up with results that can be useful for other processing units in other countries.
Application of Artificial Neural Network To Prediction Of Customer Order Amount In A Manufacturing System With Stochastic Process And Make-To-Order Strategy
Authors: Babatunde Ayanlowo , Bolu Christian , Oyawale Festus , Fayomi O.S.I.
Published: April 2021

In this study a predictive model using Artificial Neural Network architecture was developed to predict customer orders of a manufacturing system in Nigeria with stochastic process and make-to-order strategy. This arose as manufacturing outfit in Nigeria continually contend with the problem of customer churn as a result of long waiting time of customer’s order through inability to predict the order quantity of customers on a timely basis. This necessitates the application of an Artificial Neural Network Technique on the manufacturing outfit database to predict customer’s order. A multi-layer perceptron model was built with python programming language and compared with Neuro Solution Infinity Software with close to 80 thousand dataset extracted from two databases of the manufacturing outfit in Nigeria. The results showed that the Artificial Neural Network model from Python had close performance with that obtained from the Neuro Solution Infinity software. The Root-Mean-Square Error, Mean-Absolute-Error and R2 statistical metrics were used to evaluate the performance of the developed predictive model and the results of the three metrics are 226,177 and 96.53% for the python program, and 196,123 and 98.4% for the Neuro infinity software respectively. This shows that Artificial Neural Network technique made the prediction of customer’s order amount for the product-based manufacturing outfit with stochastic process and make-to-order strategy possible.
Strength Prediction of GPC using Alkali pH, Salinity, Temperature, and Conductivity as Continuous Predictors
Authors: Oyebisi S. O. , Owolabi E. F. , Owamah H. I. , Oluwafemi J. O. , Ayanbisi O. W.
Published: April 2021

This study explored the chemistry of alkaline activators, and their physical properties were used to predict the compressive strength of geopolymer concrete (GPC). Sodium silicate (Na2SiO3) gel and six various pellets of sodium hydroxide (NaOH) were used as the alkaline activators. Ground granulated blast furnace slag (GGBFS) and corncob ash (CCA) were utilized as supplementary cementitious materials (SCMs) in the production of GPC. A mix design proportion of Grade 30 MPa concrete and 14 M of alkaline activator (AA) was adopted. The concrete constituents were prepared, cured, and tested at 7, 28, 56, and 90 days. The relationship between the compressive strengths and the pH, temperature, salinity, and conductivity of alkaline activator was modelled. The experimental findings indicated that the temperature, conductivity and salinity of the alkali increased with increasing pH. Besides, the compressive strength of GPC increased with increasing alkali’s pH, temperature, conductivity, and salinity. The coefficients of determinations (R2) showed that the models were 84, 90, 90, and 89% fit to predict the relationship at 7, 28, 56, and 90 days curing, respectively. These findings can be used to predict the strength trends of GPC incorporating SCMs.
Effect of Chloride in The Electrochemical Degradation of Carbon Steel in E40 Fuel Ethanol Applications
Authors: Joseph O.O. , Ishola F.A. , Afolalu S.A. , Banjo S.O. , Busari A. , Asagba C.O. , Inegbenebor A.O.
Published: April 2021

The effect of different chloride concentration on the corrosion rate of carbon steel in E40 is presented in this study. The corrosion rates for each sample were examined using gravimetric method and polarization measurement. The samples were immersed into E40 fuel grade ethanol containing NaCl concentrations of (0, 8, 16, 24 and 32 mg/L) for a minutest of 10 days and a maximum of 40days. Results obtained from both gravimetric and polarization measurements show that as chloride concentration amplified from 0 mg/L to 32 mg/L, there was an increase in corrosion rate of the carbon steel with the exception of a slight decrease at 24 mg/L on the 30th and 40th day. Corrosion rate was observed to be dependent on exposure time.
Experimental Application of Bioclimatic Design Strategies for The Reduction of Cooling Energy Demand in Office Buildings In Tropical Hot-humid Climate
Authors: Owolabi O. S. , Adetunji O. S.
Published: April 2021

Energy consumption in buildings remains a major driver of global warming and is highly impacted by climate change. A fast-growing sector in the construction industry is office development; consuming energy (mainly for heating, cooling, air-conditioning and lighting) 10-20 times more than the residential sectors. It was implied in recent literature that a continuous increase in development means a continuous rise in energy use and building carbon footprint. The study experimented with the innovative design of an office building which explores bioclimatic design concept, optimization of the efficiency of systems and use of renewable energy to determine their impact on cooling energy demand and building carbon footprint. The study developed an experimental model and simulated it through computer simulation using the passive house planning package (phpp) to investigate cooling energy demand within the tropical warm-humid climate of Lagos, Nigeria. Simulated result of the experimental model of office building showed a reduction in cooling demand by 4.42% to achieve passive house standard. The study encourages the implementation of bioclimatic design strategies in the design of office buildings by the building professionals.
Design and Implementation of an Automated Etching System
Authors: Olowoleni J.O , Awosope C.O.A , Adoghe A.U. , Agbetuyi A. F. , Oguntosin V , Halin C.A.
Published: April 2021

: Etching is a subtractive method that is used for the production of printed circuit boards (PCBs), where acid is been used to remove unwanted copper from a prefabricated laminate [1]. The manual method of doing this can only be used for a small number of boards and is likely to be messy [2]. Besides this, exposure to some certain kinds of etchants may have adverse effects on one’s health. On the other hand, the machines available to do this provide a cleaner and faster means and can etch many boards at a time but they are very expensive. This usually discourages their purchase among small scale Printed Circuit Board (PCB) manufacturers. But the automated etching system presented here aims at providing a method of carrying out the etching process for a PCB board in a simple, clean, safe and cost effective way. The printed circuit board is mechanically designed to support and electrically to connect electronic components using conductive tracks, pads and features etched from copper sheets laminated onto a non-conductive substrate.
Thermodynamics and Parametric Study of the Grate ClinkerCooler Using the Process Model
Authors: Okoji Anthony I. , Anozie Ambrose N. , Omoleye James A. , Osuolale Funmilayo N.
Published: April 2021

In cement industries, grate coolers are commonly used for heat recovery from hot clinker discharged from the rotary kiln. The study focuses on improving a grate cooling system’s energy, exergy, and recovery efficiencies by optimizing its operating parameters such as cooling air and clinker mass flow rate. Aspen plus V10 process simulator was used to explore the impact of clinker mass, and ambient cooling airflow rate on the thermodynamics efficiencies of a cooling system for grate cooler. The energy and exergy efficiency of the grate clinker cooler gives estimates of 85.9% and 56.2 % respectively. Whereas the energy and exergy recovery of the grate clinker cooler was estimated as 75.9 % and 45.4 % respectively. It was found that a cooling system’s energy and exergy efficiencies can be improved by 2.1 % and 2.2 %, respectively, for each 5 % rise in cooling air mass. Considering the utilization of the heat recovery efficiencies of the exhaust air cooling system, energy and exergy recovery have been found to increase by 8.5 % and 9.2 % respectively. It was discovered that significant emission reductions of 0.23 % can be achieved by raising both secondary air and tertiary temperature via optimization of the grate cooler parameter, resulting in a reduction of fuel for kiln operations. Nevertheless, these units provide opportunities in great potential for energy savings, therefore the method used can also aid informed decision-making to enhance process performance.
Development of A Doum Palm Shelling Machine
Authors: Ogbole D. A. , Ademoh N.A
Published: April 2021

The traditional method used in Nigeria for removing the shell of doum palm is tedious, consumes time and also result in musculoskeletal strains and cuts. Despite an extensive search, no published literature was available on the development of a machine to shell the nuts of doum palm. To overcome this problem, a power operated doum palm de-shelling machine was designed and developed to help improve efficiency and productivity in producing vegetable ivory, doum oil and these can profoundly influence the socio-economic security of doum palm farmers. The average dimension of the doum palm nuts for the outer and inner shell layer in the three principal axes (namely, length, width, and thickness) were found to be 48.11mm, 37.69mm, 33.28mm and 32.59mm, 26.70, 23.09 respectively and its equivalent geometric mean diameter, surface area and sphericity were also found to be 39.22mm, 4832.42mm2, 81.52% and 27.18mm, 2320.86mm2, 83.39% respectively. All materials used in the fabrication of this machine are of standard specification and locally sourced. The machine is powered by a 0.70 hp electric motor and when the doum palm nuts are fed into the hopper, they pass through to the shelling unit where the shells are removed without causing damage to the nuts. The shelling units comprises of an adjuster and a shelling drum. The doum palm nuts flows to the shelling drum and they make impact with the shelling drum and the walls of the adjuster giving rise to a very great impact force that eventually shells the doum palm nuts. The shelled doum palm nut thereafter falls out through the outlet. The adjuster is used to regulate the shelling unit to the desired fit for different sizes of the doum palm nuts to be shelled. Performances test analysis conducted show that the machine shelled the fruits without nut breakage and also that the machine capacity is 2376 nuts/hr and the shelling efficiency is 73%.
Computational Fluid Dynamics Analysis of Mixed Convection Heat Transfer and Fluid Flow in a Lid-driven Square Cavity Subjected to Different Heating Conditions
Authors: Olayemi O. A. , Al-Farhany K. , Olaogun O. , Ibiwoye M. O. , Medupin R.O. , Jinadu A.
Published: April 2021

The present study investigates mixed convective and fluid flow characteristics in a lid-driven enclosure filled with air and its walls subjected to various heating conditions. The vertical (left and right) walls of the enclosure are cooled (Tc), and the bottom wall is heated to (Th) while the horizontal lid-driven upper wall is subjected to sinusoidal heating. The dimensionless governing equations (continuity, momentum, and energy transport) were implemented in COMSOL Multiphysics 5.4 software. The influences of Grashof number (103 ⩽ Gr ⩽ 105
) and Reynold number in the interval of 1 ⩽
Re
⩽ 100 on the average Nusselt number ( NU ) for all walls of the cavity was examined. Furthermore, the results presented in the form of isotherms, streamlines, and the local and average Nusselt numbers in the enclosure for
Re ⩽ 100 and
Gr
in the range of 103
⩽
Gr
⩽ 105
. The results indicated the highest and lowest average rate of heat transfer at the bottom and top walls of the cavity respectively. The top wall region presented a higher velocity as confirmed by the velocity contour plots.
Experimental Investigation in the Autoignition Behaviour of Aviation Jet Fuel in a Rapid Compression Machine
Authors: Nyong O.E , Ebieto C.E , Agbro E. , Blakey S.
Published: April 2021

Jet A-1 fuel’s autoignition behaviour was examined experimentally in a newly developed rapid compression machine (RCM) at the University of Sheffield. The experiment was conducted at a compressed temperature at compressed temperatures of 697 K ⩽ Tc ⩽ 796 K, compressed pressure of 6 and 10 bar, and under lean and stoichiometric conditions (φ = 0.75 and 1.0). The initial chamber wall temperature was varied from 115°C - 135°C. The effect of the compressed temperature, compressed pressure and equivalence ratio was seen to have influence on the ignition delay time (IDTs) of Jet A-1. In the experimental condition studied, Jet A-1 exhibited an Arrhenius behaviour that is increasing the compressed temperature, compressed pressure and equivalence ratio decreases monotonically with IDTs. Evidence of two-stage ignition delay and absence of Negative Temperature Coefficient (NTC) behaviour was observed within the condition studied.
Impact of Passive Energy Strategies on Workers Productivity in Tropical Climate
Authors: Oluwatayo A.A , Pirisola O.H
Published: April 2021

Passive building strategies in tropical climates are believed to create thermal comfort, thereby enhancing the productivity of the workforce in office buildings. Very little study, however, exists on the impact of these passive design strategies on the productivity of workers in office buildings. This study presents the results of the study on the impact of passive design strategies on the productivity of workers, taking samples from office buildings in Lagos, Nigeria. Copies of questionnaires were administered to gather the required data. Observation guides were also utilised to document passive design features in the buildings studies. Passive design strategies such as; building orientation and the optimisation of solar and ventilation by the use of shading devices were significant strategies in predicting workers’ productivity.
Biosmart Materials and Its Innovative Characteristics in Protective Composite Coating Application
Authors: Dauda K.T. , Majebi C.A , Ayoola A.A. , Agboola O. , Popoola A.P.I , Fayomi O.S.I. , Banjo S.O. , Sojobi J. , Ogunsanya A.O.
Published: April 2021

Smart materials are advanced materials capable of changing into a useful, reproducible, predictable, and often reversible way when external stimuli such as stress, light, moisture, heat, pH, electric, and magnetic fields are applied. When the external stimulus is removed from these materials, they revert to their original form by reversing their original response. Smart materials are capable of altering one or more of their properties in a non-destructive way in response to certain stimuli – and by doing so, become functional in some useful way or the other. Recent work and advancements in smart materials have led scientists to develop advanced materials in the bio-medical field. Biosmart materials currently enjoy a wide range of applications in dentistry, orthopedics, and prosthetics. Examples of these materials include Smart Ceramics, Smart Composites, Self-healing composites, Nickel-Titanium Alloy, Shape Memory Alloy, Smart Sutures, Glass Ionomers and many others. This review paper first provides an overview of bio smart materials – types, classes, characteristics, and applications – it then focuses on the specific area of the development of protective or smart coating for bio smart materials. It discusses some of the progress and advancements that have been made in this area.
Passive characteristics and Arrhenius responses of expired inhibitor drug on UNG1050 steel
Authors: Tijani S.K.U , Odulanmi O.A. , Fayomi O.S.I. , Williams A.B. , Daramola M.
Published: April 2021

The study investigated the efficiency of Artemether/Lumefantrine drug for the inhibition of mild steel corrosion in 0.625M NaCl solution using potentiodynamic polarisation. It also attempted to ascertain the inhibition method, the thermodynamic parameters involved and the adsorption mechanism. Surface morphology was also assessed through scanning electron micrography (SEM). The results confirmed that artemether/lumefantrine inhibits the corrosion of mild steel in 0.625M salt solution fairly well with an efficiency of 75% at 298 K with 20ml of inhibitor used. The efficiency reduced when temperature was increased but it increased when inhibitor concentration was raised which suggests that the inhibition efficiency is inversely proportional to temperature but directly proportional to concentration. It was found to operate with mixed inhibition and the Langmuir adsorption isotherm best matches the behaviour of the inhibitor in the experiment with a minimum correlation coefficient of 0.975.
CFD simulation for pedestrian comfort and wind safety in VIT campus for wind resource management
Authors: Prabhaharan S A , Rajasekarababu KB , Vinayagamurthy G , Sivakumar R
Published: April 2021

Recent researches on Computational Wind Engineering (CWE) studies widely focus on wind pressure coefficients and wind flow field for the aerodynamic design of buildings, urban planning and dispersion studies. Nowadays, CWE had been widely used for identifying the critical wind locations on the field for warning the pedestrians as well as harnessing the wind. Hence, highly functional regions like universities are currently equipping micro wind turbines, and roof-mounted wind turbines to meet their demands. This study focused on exploiting the wind flow conditions around the premises and wind force characteristics of the buildings situated at VIT Chennai premises for effective utilization of wind energy and determining the hot spots of unfavourable wind. By introducing CFD simulation earlier into the design process, it is easy to assess the wind resource conditions, pedestrian safety and comfort. However, the accuracy and reliability of CFD simulations can easily be compromised. For this reason, several sets of best practice guidelines have been developed in the past decades. Based on the best practices, this work presents the CFD simulation and framework for evaluating pedestrian comfort and possible areas to commission small wind turbines in the VIT campus. The simulations for assessing the wind flow conditions are carried out based on the k-∊ realizable turbulent model with high-quality grid-based convergence. The preliminary results can ensure wind comfort, safety and wind resources with CFD and add to enriched wind environmental quality in living.
Design of 3D Printed Aircraft Seat Structure using Latticing in combination with Topology Optimization and Generative Design
Authors: Noronha Wedyn , Joshi Vedant , Jeyanthi S
Published: April 2021

The aviation industry is responsible for 2% of all human-induced CO2 emissions. According to Iata (a trade body), the number of air passengers is predicted to touch 16 billion by 2050. Minimizing weight is central in achieving an ideal balance between payload and range of an aircraft and consequently, low fuel consumption. For instance, in a Boeing 787, a 20% weight savings will result in 10 to 12% superior fuel efficiency. Besides reducing carbon footprint, aircraft performance improvements like better acceleration, higher structural strength and stiffness, and increased safety could also be achieved by lightweight design. In this research paper, we propound the design of an aircraft seat structure which can be fabricated from Polyetherimide resin by 3D Printing. The structure is designed using topology optimization, generative design, and latticing. The lattice structures are made and tested on nTopology TM. The seat’s ergonomics are evaluated on Catia V5. The seat design meets all functional requirements without compromising on passenger comfort. The design can be used for standard commercial jets, and the weight savings are predicted to reduce fuel consumption drastically, resulting in lower costs and lower emissions.
Tensile properties of hybrid kenaf/glass fiber reinforced epoxy composites with different stacking sequence using experimental and FEA simulation method
Authors: Ansari M N M , Vinoth K S , Nordin Afeefah , Bassam Alaseel , Topa A
Published: April 2021

The conventional overhead transmission line insulators are usually made of glass and ceramics, but the materials are heavy and bulky. Therefore, kenaf fibre was chosen as partial replacement material to be reinforced with Glass/epoxy composite to reduce the weight and bulkiness of the composite structures. This study used Epoxy as matrix and kenaf/glass fibres to reinforce fillers to fabricate the composites in various stacking sequences. Finite Element Analysis (FEA) was carried out using LS-DYNA software to investigate the tensile properties of the hybrid composite. The results showed a significant improvement in tensile values of the modelled composite exhibited by the kenaf/glass fibre. The tensile strength of the hybrid composites was comparable with the Glass/Kenaf/Epoxy hybrid composites’ experimental results. About 200% tensile strength improvement can be observed for both experimental and numerical for G/K/G/E sample than pure epoxy samples, thus making the new composite a potential substitute for insulator applications.
Numerical Investigation on Pylon and Flush Wall Injection in Cold Coaxial Jets
Authors: Sarathkumar Sebastin J. , Jeyakumar S. , Karthik K. , Sivakumar R.
Published: April 2021

The dual combustion ramjet (DCR) engine is considered one of the promising engines for the hypersonic missile propulsion system. This paper reveals the non-reacting flow characteristics of the DCR engine with the influence of pylon and wall injections in coaxial jets using numerical investigation. The supersonic combustor of the DCR engine is modeled and analysed using the commercial CFD software ANSYS 18.0. The three-dimensional compressible Reynolds-averaged Navier-Stokes (RANS) equations coupled with the SST k - ω turbulence model have been used to analyse the coaxial mixing characteristics of the jets. The numerical study is validated with the experimental data and agrees with it for further investigation. The pylon and wall injectors are located symmetrically at the gas generator’s nozzle exit, and the air is used as the injectant to simulate gaseous fuel. The pylon and wall injection results are compared with the actual DCR engine. In a typical DCR engine, the shock waves generated from the gas generator nozzle enhance the mixing of the coaxial jets with minimum total pressure loss. The pylon injection induces more shock interactions along the flow direction within the supersonic combustor leading to higher total pressure loss than the wall injection. The pylon injection provides the spatial distribution of fuels compared to the wall injection in the coaxial supersonic flow field.
3-E Analysis of a 3x500 MW coal fired thermal power plant using alternative coals species
Authors: Rajeev Vishnu , Sreekanth M , Feroskhan M , Daniel Joseph
Published: April 2021

This article reports a study conducted to understand the influence of different coal species on the performance of a thermal power plant. The aim is to understand the difficulties in replacing an existing coal with another available species. The methodology of 3-E (Energy, Exergy and Environment) analysis has been implemented on a 3x500 MW coal fired thermal power plant located in South India. The power plant is modelled using flow sheeting software called Cycle-Tempo. Key operating parameters like temperatures, mass flow rates were compared with the operating parameters and were found to be in good agreement. Maximum exergy loss for the design coal was found to occur in the combustor (36.5%), and the least exergy loss occurred in the de-aerator (0.13%). Optimization of the power plant was carried out with the aim of maximizing the efficiency, and the energy and exergy efficiencies obtained for the power plant were 34.35% and 33.64% respectively. Simulations were carried out with six different coal species, namely (i) Raniganj, (ii) Giridih, (iii) East Bokaro, (iv) West Bokaro, (v) Wardha valley, and (vi) Korba coals and various parameters that influence the performance were examined. An environment analysis was also carried out to study the emissions caused by the different species. East Bokaro coal turned out to be the best coal from efficiency viewpoint whereas Korba coal has the lowest amount of CO2 produced per MW power generated.
Buckling and Vibration Behavior of Composite Beam due to Axially Varying In-plane Loads
Authors: Kanade Sangram Anil , Chinnapandi Lenin Babu Mailan , Jeyaraj P , Subramanian Jeyanthi
Published: April 2021

In this work buckling and vibration behavior of composite beam is analyzed based on the shear and normal deformable beam theory (SNDBT) by using Ritz method. The effects of aspect ratios, boundary conditions, fiber angles on the buckling and vibration subjected to non-uniform axial loads studied in detail. The obtained numerical results in terms of dimensionless fundamental frequencies and dimensionless first critical buckling loads are compared with the results from previous research for convergence studies.
Freezing water simulations in isochoric systems – preliminary analysis
Authors: Beşchea G A , Câmpean Ş I , Scutaru L M , Costiuc L , Şerban A
Published: April 2021

Freezing liquids into ice is a complex simulation and is called a phase transformation or phase change. Isochoric (constant volume) preservation is a new thermodynamic concept that takes advantage of an until now ignored aspect of thermodynamics, life under conditions of constant volume as opposed to the conventionally studied life conditions of constant pressure. Isochoric system are simple constant volume devices, made of steel, capable of withstanding the pressures that develop in the system, with minimal deformation. Because ice-I is less dense than water, the formation of an ice nucleus in an isochoric (constant volume) chamber will cause an increase in pressure. Traditionally, ice formation is performed in an isobaric process (constant pressure) at 1 atm, because this is our natural environment and it is most convenient experimentally. The goal of this study is to introduce the fundamental thermodynamic principles and boundary conditions of isochoric (constant volume) simulations at low temperatures. In this analysis we intend to shows that homogeneous ice nucleation can be thermodynamically improbable in an isochoric system.
High performance buildings with optimized energy systems based on exergy principles
Authors: Boian I , Tuns I
Published: April 2021

Optimising buildings and energy systems with a focus on mitigation of greenhouse gas emission is not an easy task: first, principles are necessary to be established and then the steps to be followed. Exergy efficiency can show the best issues: building envelope insulation and air tightening, low-valued energy sources, low-exergy heating and cooling systems, avoiding destructive exergy-processes like boilers burning fossil fuels, systems and grids for low-temperature heating and for high temperature cooling, renewable energy sources, daylight, and passive solar energy use supported by control strategies of building systems can contribute to a better future when considering global warming and comfort.
Considerations on the efficient functioning of the urban water pumping stations
Authors: Cojanu V , Helerea E
Published: April 2021

Current urban water systems aim to ensure hydraulic and water quality parameters for all consumers connected to the water distribution network, with the highest possible efficiency. This corresponds to reduce primary energy consumption and a responsible control of drinking water sources in order to supply water to urban areas. Most of the time, a low efficiency of water supply systems is due to the following factors: inefficient operation, poor maintenance, incorrect sizing and unmetered water consumption. This article analyzes the efficiency of the solutions applied in the pumping station as a component part of the water supply systems. The case study focuses on the operation of pumps in water supply systems and presents the analysis of the relationship between water consumption and electricity of a pumping group in an urban water supply system. This paper is a first step in order to obtain global parameters for energy optimization of the urban water system.
Conversion of industrial liquid construction waste with plasma on hydrogen
Authors: Cucos I , Isopescu D N , Antonescu I , Alecu C I , Caunii V , Cucos V C , Agavriloaie M O
Published: April 2021

This paper presents a modern system for conversion with plasma with hydrogen of industrial liquid waste which has implemented a control system through thermoregulatory with PID control laws. Modeling and simulation of thermochemical plasma process performed using specialized software Matlab & Simulink, Ansys allows the optimum control of the temperatures and chemical reactions of the plasma reactor on hydrogen, allowing the conversion of hazardous industrial liquid waste into electrical and thermal energy and useful raw materials that can be reused in the production process.
Quantitative fire risk assessment for an office building
Authors: Dârmon R
Published: April 2021

In Romania, the risk of a fire occurring within a building is determined in a very conservative manner, as a function of the building occupancy type and the thermal load contained within each enclosure. The result is a qualitative expression of low, moderate or high fire risk. On the other hand, the fire is a serious hazard which has to be taken into account within the decision-making process by any organisation for the elaboration of their risk assessments and the risk management strategies. Nevertheless, the one carrying out a fire risk assessment has a various range of methods and techniques to apply, [1, 2] since the legislation does not specifically require a certain approach. This article is an example study of the application of Bayesian statistics to determine the probability of a fire occurring within an office building, due to an electrical fault.
Comparative analysis of two seismic energy dissipation solutions in the case of a steel structure
Authors: Tepes-Onea F , Vintila D , Tudose C
Published: April 2021

The present paper aims at the comparative analysis of two seismic energy dissipation solutions for a steel structure in frames. We opted for non-braced frames and centrally braced frames. In the case of unbroken frames, the resistance structure consists of steel beams and columns. Potential plastic areas are formed mainly at the ends of the rulers and, to a lesser extent, in columns. Horizontal actions are mainly taken by bending the structural elements. To ensure the most efficient observance of the rigidity requirements for lateral actions, the solution of the rigid beam-column joint is required. The use of the concept of weak beam-strong column leads to the appearance of plastic joints in the beams, close to their joints with the columns. Centric braced frames can take over the horizontal actions, which are manifested in their plane, through axial forces. Energy dissipation occurs mainly by plasticizing the extended diagonals. The comparative analysis consists of highlighting the results obtained from the structural calculation with the help of a commercial automatic calculation program for the two solutions: non-braced frames and centrally braced frames. An office building with 2 levels was analyzed, located in Constanta, where the two types of the staff were provided in turn. The obtained results will be compared from the point of view of the amount of steel used, so from the economic point of view. Another comparison refers to the displacements to SLS and SLU and to the seismic energy dissipation capacity. Finally, another possible comparison refers to the over-resistance of the structural system.
The influence of calcination temperature on the optical, morphological properties and photocatalytic activity of lanthanum orthoferrite
Authors: Aisyah Jamaludin Nur , Aziz Farhana , Yusof Norhaniza , Jaafar Juhana , Norharyati Wan Salleh Wan
Published: April 2021

In this study, the effect of calcination temperature towards the optical, morphological properties and photocatalytic degradation performance of the synthesized LaFeO3 were investigated. The precursor and synthesized LaFeO3 calcined at 500-900 ºC were characterized using X-ray diffractometer (XRD), Thermogravimetric analysis (TGA), UV-Vis spectrophotometer, Fourier Transform Infrared Spectroscopy (FTIR) and BET. The photocatalytic activity of the synthesized LaFeO3 was performed on oily wastewater. The photocatalytic degradation performance of LaFeO3-600 is 67%, 72% and 63% for 1000ppm, 10000ppm and 20000ppm respectively. This study verified that calcination temperatures have a major impact on the optical, structural and morphological properties of nanoparticles.
Review on recent advance biosynthesis of TiO2nanoparticles from plant-mediated materials: characterization, mechanism and application
Authors: Syamsol Bahri Syamsutajri , Harun Zawati , Khadijah Hubadillah Siti , Norhayati Wan Salleh Wan , Rosman Nurafiqah , Hasliza Kamaruddin Noor , Hafeez Azhar Faiz , Sazali Norsuhailizah , Adiba Raja Ahmad Raja , Basri Hatijah
Published: April 2021

Titanium dioxide, TiO2nanoparticles are being utilized in various application of science and technology including membrane, medical, electrical and chemical field for their respective worth which generally attributed to the self-cleaning and photocatalytic ability, good band gap, an antibacterial as well as physical and chemical stability. As commonly known conventional TiO2nanoparticles synthesized using chemicals as reducing agents has become accountable for various biological risks due to their general toxicity, thus engendering the serious concern in developing environment friendly processes. Naturally derived products, such as extracts of plants that composed of biomolecules, have been used intensively recently as a reductant agent, that also sometimes can be acting as capping agents after synthesis process. These natural biomolecules mostly consisted of polyphenols have been identified to be actively play a role in this biosynthesis of nanoparticles from any plants extract that able to form different shapes and sizes of nanoparticles with better surface reactive area, characteristic and properties. Therefore, biosynthesis can be considered as a driving force for the greener, safe and environmentally friendly for many applications that have used TiO2particles either used as additive, purely or in composite form. The present review targets on the ‘greener’ routes of synthesis TiO2nanoparticles with an emphasis on experimental conditions based on sustainable methodologies and also explores the huge plant diversity to be utilized. The use of ‘greener’ not only reduces the cost of synthesis but also minimizes the need of using hazardous chemicals and stimulates green synthesis. This review also focuses on aspects characteristic and properties that generated from the output of this green process that make it strongly applicable to certain applications as for binding of biomolecules, to the biosynthesized is significantly benefit to biomedical fields. It is expected that these outstanding findings will encourage researchers and attract newcomers to continue and extend the exploration of possibilities offered by nature and the design of innovative and safer methodologies towards the synthesis of nanomaterials, possessing desired features and exhibiting valuable properties that can be exploited in a profusion of fields.
Flow pattern, pressure drop and inclination analysis on liquid-liquid two phase flow of waxy crude oil in pipelines using PIPESIM
Authors: Alpandi A H , Mazeli A H , Sidek A , Husin H , Junin R , Jaafar M Z
Published: April 2021

Produced water is a water that comes out with the crude oil during the production of the well. It contains non-soluble and soluble oil or organics, dissolved and suspended solids with different chemicals used during production process. Thus, it must be properly accounted as it affects the economical productivity of crude oil and separation efficiency as a result of stubborn emulsions between crude oil and water. Thus, a simulation study was conducted using PIPESIM to predict the flow pattern and pressure drop of waxy crude oil and water flow in horizontal and inclined pipelines (i.e., -15° from horizontal). In this simulation study, water cuts were ranging from 0% to 90% while the flow rates were ranging from 2.03 to 16.21 cm3/s. The study comprised fluid modelling, physical modelling and running the simulation with the most suitable multiphase flow correlation in PIPESIM. This simulation study used the waxy crude oil has 16.15% of wax content and simulation was performed at 30°C. The validity of the simulation results was accomplished by comparing the published findings. There were only two types of flow patterns that can be identified by PIPESIM; stratified wavy and dispersed flow. The investigations proved that pressure drop was greatly influenced by flow rates and flow patterns. By decreasing the inclination angle, the boundary between the stratified and dispersed flow regimes shifted to the upper left of the flow pattern map while showing a higher pressure drop than horizontal pipeline due to the combined effect of pressure difference and gravity. The simulation results can be used as a platform for better understanding on more complex cases of gas, oil and water concurrent flow in pipelines.
Ionic Conductivity and Structural Properties for CMC - AN in Propylene Carbonate as Plasticizer in Solid Biopolymer Electrolytes
Authors: Ahmad N.H. , Nurhafizah H.
Published: April 2021

The present study aims to investigate the structural and ionic conductivity of carboxymethyl cellulose (CMC) - ammonium nitrate (AN) – propylene carbonate (PC) as proton conducting polymer electrolytes. The CMC-AN-PC were prepared via solution casting technique. The complexion of polymer electrolyte films has been confirmed via FTIR studies. Fourier transform infrared (FTIR) spectra showed the occurrence of complexation between the polymer electrolyte components. Impedance studies reveals that the highest ionic conductivity of CMC-AN-5wt% PC 6.5 × 10−3 Scm−1 was observed in polymer electrolyte system obtained at ambient temperature.
Textile dye Reactive Black 5 (RB5) removal by visible light photocatalyst and its characterization
Authors: Mohamed Noor S H , Othman M H D , Jaafar J , Rahman M A , Ismail A F
Published: April 2021

Visible light photocatalysis is now a subject of interest for researchers to explore further in the treatment of wastewater as it can save costs and be environmentally friendly. Cadmium sulphide (CdS) is one of the photocatalysts of visible light that has excellent properties and a low band gap. The toxicity and carcinogenicity of textile industry effluent containing predominantly textile dyes disturbs the environment. In this study, the removal of reactive black 5 (RB5), the most used dyes with CdS as visible light photocatalyst, was tested. Using X-ray diffraction (XRD), scanning electron microscope (SEM), ultraviolet-visible-near infrared (UV-Vis-NIR) spectrophotometers and photocatalytic tests under visible light, the physical and chemical properties of CdS were characterised. CdS has an irregular shape and this can be demonstrated through SEM. The band gap obtained was 2.12 eV and this was associated with the degradation efficiency of CdS under visible light as it can degrade RB5 after 360 minutes of exposure by up to 80 percent. This study proves that CdS is a strong photocatalyst of visible light that has a small band gap and crystalline particles.