Refractive Indices of Aqueous Solutions of Isomeric Butylamines at 303.15 K: Experimental and Correlative Approach

Refractive indices () and densities (r) of water (W) + n-butylamine (NBA), + sec-butylamine (SBA) and + tert-butylamine (TBA) systems had been measured in the whole range of composition at 303.15 K, from which deviation in refractive index (DnD ) molar refraction (Rm) and excess molar refraction () had been evaluated. All of the derived properties were fitted to appropriate polynomials. DnD were fitted to the Redlich-Kister polynomial equation. Values of DnD were all positive and were all negative which were attributed to cross hydrogen bonding, specific interactions as well as interstitial accommodation effect. A comparative study of Lorentz-Lorenz (L-L), Weiner (W), Heller (H), Gladstone-Dale (G-D), Arago-Biot (A-B), Eykman (Eyk), Newton (Nw), Eyring-John (E-J) and Oster (Os) relations for determining the refractive index of a liquid had been carried out to test their validity for the three binaries over the entire mole fraction range of butylamines at 303.15 K.

Influence of Propanol as Additive with Diesel Jatropha Biodiesel Blend Fuel for Diesel Engine

Fossil fuels are widely recognized as non-renewable energy resources. They play an important role in our daily life because they can be used in various applications such as the production of soap and cosmetics, as an energy source and for transportation. However, the use of these fossil fuels causes negative impacts on humans, animals and the environment. These happen due to the emission of harmful gases into the atmosphere. Not only that, the available fossil fuels are decreasing due to continuous usage by humans. As a result, researchers investigated finding alternative ways to overcome this issue by replacing diesel fuel with biodiesel. Biodiesel is more environmentally friendly relative to diesel fuel. A research study was conducted involving biodiesel. The purpose of this study was to produce Jatropha Biodiesel, as well as evaluate the properties of Jatropha biodiesel and diesel Jatropha biodiesel blended with propanol. The production of Jatropha Biodiesel was done by using two-step transesterification which was an acid-catalyzed transesterification and base-catalyzed transesterification. Different methanol to oil ratios had been used to identify the best ratio to reduce the FFA content in the CJO. 9:1 was the best methanol to oil ratio and then tested with different catalyst weights. It was found that an increase in the weight of catalyst might reduce the amount of biodiesel yield. In addition, this study also investigated and predicted the engine performance and characteristics of diesel Jatropha biodiesel blended with propanol at different blending ratios. The properties of these test fuels were studied. Bomb calorimeter, Fourier Transform Infrared Spectroscopy (FT-IR) analysis and Diesel Engine test were done. Thus, the calorific value and functional group of the test fuels were identified and determined. The calorific value of biodiesel was much higher than conventional diesel due to the existence of oxygen. This could be proven as the analysis of FT-IR also showed a (C=O) bond which reflected the presence of oxygen. The oxygen helped in combustion besides reducing the hydrocarbon released into the air. These findings were then reflected and related to the performance of diesel engines.

Modelling and Dynamic Simulation of One-Dimensional Isothermal Axial Dispersion Tubular Reactors with Power Law and Langmuir-Hinshelwood-Hougen Watson Kinetics

In this paper, the modelling, numerical lumping and simulation of the dynamics of one-dimensional, isothermal axial dispersion tubular reactors for single, irreversible reactions with Power Law (PL) and Langmuir-Hinshelwood-Hougen-Watson (LHHW)-type kinetics are presented. For the PL-type kinetics, first-order and second-order reactions are considered, while Michaelis-Menten and ethylene hydrogenation or enzyme substrate-inhibited reactions are considered for the LHHW-type kinetics. The partial differential equations (PDEs) developed for the one-dimensional, isothermal axial dispersion tubular reactors with both the PL and LHHW-type kinetics are lumped to ordinary differential equations (ODEs) using the global orthogonal collocation technique. For the nominal design/operating parameters considered, using only 3 or 4 collocation points, are found to adequately simulate the dynamic response of the systems. On the other hand, simulations over a range of the design/operating parameters require between 5 to 7 collocations points for better results, especially as the Peclet number for mass transfer is increased from the nominal value to 100. The orthogonal collocation models are used to carry out parametric studies of the dynamic response behaviours of the one-dimensional, isothermal axial dispersion tubular reactors for the four reaction kinetics. For each of the four types of reaction kinetics considered, graphical plots are presented to show the effects of the inlet feed concentration, Peclet number for mass transfer and the Damköhler number on the reactor exit concentration dynamics to step-change in the inlet feed concentration. The internal dynamics of the linear (or linearized) systems are examined by computing the eigenvalues of the linear (or linearized) lumped orthogonal collocation models. The relatively small order of the lumped orthogonal collocation dynamic models make them attractive and useful for dynamic resilience analysis and control system analysis/design studies.

Design of Effective 33/11 kV Injection Substations Using International Standards

This research focuses on the design of an effective 33/11 kV modelled injection substation that conforms to an appropriate standard for equipment protection, the safety of personnel and power quality compliance. This is to provide a solution to one of the major problems industries in Nigeria faces due to sudden voltage fluctuations in the power system which results in damages to equipment and thus outage of power supply and damages to substation equipment. The methodology involved designing an effective 33/11 kV injection substation and associated distributive substation elements using international codes and applicable algorithms. 60% loading of transformer and additional 1.25 factor of future expansion (F.E) were considered too. The results showed that a 7.5 MVA injection transformer was designed to operate at 60%. Also, the results revealed that the injection substation would feed 15 numbers of 500 kVA distributive transformers. Each distribution substation was sized in accordance with the 7.5MVA injection transformer philosophy in this work. This research concludes that the injection substation must be loaded at 60% with an additional 1.25 F.E. in order to increase the transformer life span, and the 7.5MVA injection substation can crater for 15nos of 500 kVA distribution transformers in this research. Each substation will reliably and effectively carry the expected load demand. This research recommends that injection substations should be designed for areas with high energy requirements for reliable power quality. It recommends that substations should conform to 60% loading at the initial years of usage and that the substation design should conform to appropriate standards used in this work.

DFT Based Comparative Studies of Some Glucofuranose and Glucopyranoside Esters and Ethers

Carbohydrate-based molecular scaffolding received significant interest due to its impact on the drug discovery and development in synthetic carbohydrate chemistry during the last couple of decades. In this respect, four glucose compounds in the furanose and pyranose forms with ester and ether functionality were selected for their structural, thermodynamic and chemical reactivity studies. PASS predication indicated that the glucose in the six-membered pyranose form was more prone to biological properties compared to their five-membered furanose form. Also, in the pyranose form acetate ester (3) had more potentiality than the ethyl ether (4). The HOMO-LUMO energy gaps were almost similar for both monosubstituted furanose and pyranose glucose indicating their almost similar reactivities. It was also inferred that these 6-O-substituted compounds followed Lipinski’s rule with the acceptable range of ADMET levels, and hence, safe from lethal proarrhythmic risks. Hopefully, these results can be used in the near future for their probable pharmaceutical use without any remarkable toxicity.

Assessing the Relationship among the Land Surface Features: A Geographic Information System (GIS) and Remote Sensing (RS) Based Approach for City Area

Due to climate change and urbanization, it is important to monitor and evaluate the components of the environment. For this reason, ward-22 and ward-27 of the Khulna City Corporation (KCC) area have been selected for the study. This research seeks to identify the existing land use profile and assess the land surface components such as topography, Normalized Difference Buildup Index (NDBI), Normalized Difference Vegetation Index (NDVI), Normalized Difference Moisture Index (NDMI), Normalized Difference Salinity Index (NDSI) and Land Surface Temperature (LST) to measure the relationships among the land surface components. The land use land cover map shows that about 59% of ward-22 and 71.5% area of ward-27 are built-up areas. Both of the wards contain little amount of water body, vegetation and open space. Both of the wards have residential land use types with commercial purposes on the periphery. Accordingly, 63.32% and 65% of structures of ward-22 and 27 are pucca. The land surface components reveal that both areas contain lower slopes, less vegetation, less moisture, severe salinity, highly built-up areas, and high land surface temperature. The relationships among the land surface components show that NDVI has a negative relation with LST and NDBI whereas NDVI represents a positive correlation with NDMI. On the other hand, NDBI shows a positive correlation with LST whereas NDMI negatively correlates with LST. NDSI and topography reflect no meaningful relationship between NDBI, NDVI, LST, and NDMI. However, the research findings may be essential to city planners and decision-makers for incorporating better urban management at the micro level concerning climate change.

Automated Classification of Breast Cancer Lesions for Digitised Mammograms via Computer-Aided Diagnosis System

Women with breast cancer have a high risk of death. Digitised mammograms can be used to detect the early stage of breast cancer. However, digitised mammograms suffer low contrast appearances that may lead to misdiagnosis. This paper proposes a Computer-Aided Diagnosis (CAD) system of automated classification of breast cancer lesions using a modified image processing technique of Fuzzy Anisotropic Diffusion Histogram Equalization Contrast Adaptive Limited (FADHECAL) incorporated with Multilevel Otsu Thresholding on digitised mammograms. Four main blocks were used in this CAD system, namely; (i) Pre-processing and Enhancement block; (ii) Segmentation block; (iii) Region of Interests (ROIs) Extraction block; and (iv) Classification block. The CAD system was tested on 30 digitised mammograms retrieved from the Mini-Mammographic Image Analysis Society (MIAS) database with various degrees of severity and background tissues. The proposed CAD system showed a high accuracy of 96.67% for the detection of breast cancer lesions.

Evaluation of Green Elements and Thermal Comfort Condition of Assyafaah Mosque, Singapore

A mosque is a place for worship and religious activities that are traditionally built with a typical design and shape with a dome and minaret as its traditional symbols. The most basic design of a mosque is a simple single-storey rectangular-shaped building with a prayer hall inside it. Design in the past was influenced by social and cultural aspects. However, regional and climatic differences have led to thermal discomfort and unnecessary energy use if the mosque is not properly designed. Therefore, there is a need to consider comprehensive planning and review for passive design to avoid thermal discomfort and excessive use of energy. Assyafaah Mosque in Singapore is one example that considers sustainable elements in its design. While Singapore is located very near to the hot equatorial line, many passive and green features have been integrated into the design and construction of the mosque, and this made it possible to achieve an acceptable thermal condition according to the adaptive and PMV thermal comfort model. The design maximizes the potential of naturally ventilated design with other passive strategies which allow for both thermal comfort and energy saving. This paper aims to study the impact of natural ventilation and other passive design decisions on the thermal comfort of the Assyafaah mosque in a hot and humid climate.

Effect of Fibre Hybridization on Mechanical Properties of Nylon-Broom Grass/Root-Broom Grass Fibre Reinforced Hybrid Polypropylene Composites

In the present research, nylon-broom grass and onion root-broom grass reinforced hybrid polypropylene composites were manufactured using a hot press machine. Three different levels of fibre loading (5, 10, and 15 wt.%) with fibre ratios of 1:1 were incorporated in the polypropylene matrix. Tensile, flexural, impact and hardness tests of the composites were subsequently carried out. The two combinations showed opposite trends for tensile strength and impact strength and similar trends for Young’s modulus, elongation, flexural properties and hardness. Tensile strength of the onion root containing composites increased with an increase of fibre loading, while in the nylon containing composites, tensile strength decreased with an increase in fibre loading. Their Young’s modulus increased and % elongation decreased with an increase in fibre content. Both flexural strength and flexural modulus increased with an increase in fibre content in both combinations. The impact strength of the onion root containing composites decreased with an increase in fibre loading, while the nylon containing composites showed the opposite trend. The hardness of both combinations increased with an increase in fibre content. The best set of properties were found at 15 wt% fibre loading in the nylon-broom grass-PP hybrid composite.

Chemical Reactivity Descriptors and Molecular Docking Studies of Octyl 6-O-hexanoyl-β-D-glucopyranosides

The present study describes different chemical reactivity predictions of 6-O-hexanoylation of octyl β-D-glucopyranosides prepared from octyl β-D-glucopyranoside (OBG). Also, molecular docking of the OBGs was conducted against SARS-CoV-2 main protease (6LU7), urate oxidase (Aspergillus flavus; 1R51) and glucoamylase (Aspergillus niger; 1KUL). DFT optimization indicated that glucoside 1 and its ester derivatives 2-7 exist in 4C1 conformation with C1 symmetry. Interestingly, the addition of ester group(s) decreased the HOMO-LUMO gap (Δԑ) of glucosides indicating their good chemical reactivities, whereas the other chemical reactivity descriptors indicated their moderate reactive nature. This fact of moderate reactivity was confirmed by their molecular docking with 6LU7, 1R51 and 1KUL. All the esters showed a moderate binding affinity with these three proteins. More importantly, incorporation of the ester group(s) increased binding affinity with 6LU7 and 1R51, whereas decreased with 1KUL as compared to non-ester OBG 1.