Digital Forensic Readiness in Megacities

As megacities emerge in splendor, so also do threats to security and sustainability of these cities. Earlier research found out that the leading threat amongst several security and safety threats in megacities are organized crimes. Since technology is involved in all facets of megacities, including the threats therein, this paper seeks to stimulate scientific curiosity in finding out effective and sustainable ways of harnessing technology in readiness, to protect these cities from threats rather than reactively responding to them. Using Lagos State, an emerging mega city as a case study, we seek how to systematically execute this concern which should be built from the scratch into megacities systems.A Megacity Digital Forensic Readiness Model (MEDFORM) is proposed in this paper

Effect of moisture sorption hysteresis on thermodynamic properties of two millet varieties

Application of reversible thermodynamic principles to gain fundamental understanding of food–water interactions in foods has met with limited success due to the presence of moisture sorption hysteresis which is a manifestation of irreversibility. This study was aimed at understanding the nature and extent of influence of hysteresis on thermodynamic properties of two millet varieties namely EX-BORNO and SOSAT C88. Moisture sorption data (adsorption and desorption) in the water activity and temperature ranges of 0.07 – 0.98 and 30°C – 70°C, respectively were used. Ratio of latent heat of moisture sorption to the latent heat of pure water was determined using Clausius-Clapeyron equation. Effect of moisture content on ratio of latent heat of sorption to latent heat of pure water was determined using Gallaher model. Net integral enthalpy was determined at constant spreading pressure with monolayer moisture contents calculated using Brunauer-Emmett-Teller (BET) and Guggenheim-Anderson-de Boer (GAB) models. Spreading pressure was determined using an analytical procedure. Gibbs equation was used to evaluate net integral entropy. Net isosteric heat of sorption and differential entropy were evaluated and used to investigate the enthalpy‐entropy compensation theory. Latent heat of moisture sorption in the two millet varieties decreased with increase in moisture content and approached latent heat of pure water at a ‘free water’ point of between 32% and 42% moisture content (d.b.) in adsorption and desorption, respectively. Desorption latent heat of moisture was higher than the adsorption values and the difference decreased with increase in moisture content. Monolayer moisture content decreased with increase in temperature, with the GAB being higher than the BET values. Desorption monolayer moisture was higher than that of adsorption. Spreading pressure increased with increase in water activity, with adsorption isotherm being higher than that of desorption and temperature having no significant effect. Net integral enthalpy decreased with increase in moisture content with effect of hysteresis being more marked in EX-BORNO than in SOSAT C88. Net integral entropy decreased with increase in moisture content to minimum values and thereafter, maintained sinusoidal trend with adsorption curve lagging behind desorption and varnishing at 18% and 16% (db) moisture content in EX-BORNO and SOSAT C88 respectively. Net isosteric heat of sorption and differential entropy decreased with increase in moisture content with effect of hysteresis being more pronounced in EX-BORNO. Moisture sorption process in the grains was found to be enthalpy driven with differential enthalpy varying linearly with differential entropy. Inequality in isokinetic and harmonic mean temperatures confirmed the enthalpy‐entropy compensation theory. Hysteresis was found to have effect on the isokinetic temperature, causing the values of desorption isokinetic temperature to be higher than the adsorption values

Development of a paddy rice de-husking cum polishing machine

Locally processed rice by small to medium scale processors are still not fully appreciated due to low quality. Paddy rice de-husking cum polishing machine was designed, fabricated and evaluated for its performance efficiency. The effects of paddy moisture content, speed of rotation, and polishing time on the machine performance and milling properties were evaluated. The economic analysis of the machine was also evaluated. Moisture content and speed of rotation of the shaft had effect on the throughput capacity (TC), head rice yield (HRY), percentage broken rice (BR), but not on the percentage un-dehusked (PUD) in production of brown rice. The moisture content, speed of rotation, and polishing time had effect on the BR and PUD, but not on the HRY in the production of polished rice. The minimum and maximum values for brown rice were TC (25.38 and 41.25 Kg/hr), PUD (15.77 and 46.42 %), HRY (50.47 and 67.75 %), BR (2.17 and 12.03 %). Minimum and maximum values for polished rice were PUD (1.12 and 7.34 %), HRY (78.97 and 90.50 %), BR (2.77 and 10.41 %). Economic evaluation shows that the developed de-husker cum polisher is beneficial and can be adopted by small to medium scale rice processors

Influence of chitosan edible coating on postharvest qualities of Capsicum annum L. during storage in evaporative cooling system

Chitosan is a biopolymer edible coating which can act as physical barrierwhen coated on fruits and efficiently alter their internal atmosphere and delay the ripening process. This study evaluates the usage of chitosan (CH) as edible coating to extend the shelf life of green bell pepper. Physiochemical and microbial analysis of the green bell pepper was conducted during evaporative coolant structure storage (ECS). The effect of chitosan coating on green bell pepper significantly delayed a loss in firmness, weight loss, and vitamin C content and inhibited the growth of heterotrophic bacteria, mesophilic bacteria, yeast and mould during the five weeks of storage. On the whole, this study established that edible coating from chitosan could form a natural and permanent replacement to the chemically preservatives used for postharvest management of green bell pepper

Mechanism and Isotherm Modeling of Effective Adsorption of Malachite Green as Endocrine Disruptive Dye using Acid Functionalized Maize Cob (AFMC)

Cationic Malachite green has been identified as a candidate of endocrine disruptive compound found in the environment. In this study, the mechanism and isotherm modeling of effective adsorption of cationic malachite green dye onto acid functionalized maize cob (AFMC) was investigated by batch technique. The operational parameters such as initial concentration (100 – 600 mg/L); contact time (10 – 120 mins) and pH (3 – 10) influenced the removal efficiency and quantity adsorbed. Maximum of 99.3% removal efficiency was obtained at optimum conditions. AFMC physicochemical properties (surface area 1329 m2 /g and particle size 300μm0.97 and consistently low values of SSE, X2, HYBRID and MSPD adsorption statistical error functions (ASEF), equilibrium data were best fitted to Freundlich isotherm. Kinetic data were best described by pseudo second-order model with consistent R2 >0.98 and validated by ASEF. The mechanism of process was better described by intraparticle diffusion. Evidence of adsorption process was confirmed by change in morphology and surface chemistry determined by SEM and FTIR respectively. The performance of AFMC enlisted it as a sustainable and promising low-cost adsorbent from agro-residue for treatment of endocrine disruptive dye polluted water

Anaerobic conversion of Chromolaena odorata (Siam weed) to biogas

This study evaluated the anaerobic mono-digestion of two different samples of Chromolaena odorata. Combinations of mechanical and thermo-alkaline pretreatments were applied to one of the two samples and labeled as ‘‘X’’ while the second had no thermo-alkaline treatment and was labeled as ‘‘Y’’. The Central Composite Design was used to design the pre treatments. The physicochemical characteristics of the substrates were carried out using standard methods after appropriate pretreatments. From the experimental set-ups, the most probable actual biogas yields in experiments ‘‘X’’ and ’’Y’’ were 0.3554 m3/kg Total Solid (TS)fed and 0.1803 m3/kg TSfed with the desirability of 99 and 100%, respectively. Further shown in the result is a 49.2% higher experimental (actual) biogas yield in experiment ‘‘X’’ over ‘‘Y’’. Gas chromatographic analysis revealed the CH4 and CO2 content of both experiments to be 65±1.5%; 21±3% and 53.5±2.5%; 26±3%, respectively. Combination of different pretreatment methods enhanced enormous biogas yield from the digested substrates. Optimization of the generated biogas data was carried out using the Response Surface Methodology (RSM) and the Artificial Neural Networks (ANNs). The coefficient of determination (R2) for RSM was lower compared to that of ANN. This shows that ANN

Biochemical conversion of fruit rind of Telfairia occidentalis (fluted pumpkin) and poultry manure

Environmental pollution by solid wastes and inadequate energy supply are some of the major challenges facing the developing world. This study evaluated the potentials of Fluted pumpkin fruit rind and poultry manure for biogas generation. Mechanical and thermo-alkaline pre-treatments were applied to two samples labeled ‘O’ and ‘P’ while the third sample (Q) had no thermo-alkaline treatment. The physicochemical characteristics of the substrates revealed richness in nutrients and mineral elements. The results showed that use of a combination of pre-treatment methods enhanced the biogas yield in the pre-treated substrates. Analysis of the gas composition showed 66.5 ± 2.5% Methane, 25 ± 1% Carbon dioxide; 58.5 ± 2.5% Methane, 26 ± 1% Carbon dioxide; 54.5 ± 1.5% Methane, 28 ± 2% Carbon dioxide for the three experiments, respectively. All the obtained values show the models had a high predictive ability. The substrates should be further used for energy generatio

Recent advances on graphyne and its family members as membrane materials for water purification and desalination

Graphyne and its family members (GFMs) are allotropes of carbon (a class of 2D materials) having unique properties in form of structures, pores and atom hybridizations. Owing to their unique properties, GFMs have been widely utilized in various practical and theoretical applications. In the past decade, GFMs have received considerable attention in the area of water purification and desalination, especially in theoretical and computational aspects. More recently, GFMs have shown greater prospects in achieving optimal separation performance than the experimentally derived commercial polyamide membranes. In this review, recent theoretical and computational advances made in the GFMs research as it relates to water purification and desalination are summarized. Brief details on the properties of GFMs and the commonly used computational methods were described. More specifically, we systematically reviewed the various computational approaches employed with emphasis on the predicted permeability and selectivity of the GFM membranes. Finally, the current challenges limiting their large-scale practical applications coupled with the possible research directions for overcoming the challenges are proposed

Design, Construction and Performance Evaluation of a Motorized Rice De-stoning Machine

A motorized rice de-stoning machine was locally developed for separating stone pebbles from milled rice. Major component being the reciprocating screen coupled with the blower and the hopper. The stone separation is achieved by vertical oscillation of the reciprocating screen coupled with a suction – like air produced by the blower directly beneath the screen causing rice – mixture to float just above the screen and the stones are sucked up the reciprocating screen then discharged through the stone chute and the clean rice collected in opposite order. The de-stoning machine was designed to be powered by a high speed (2980 rpm) 1 hp electric motor. It was evaluated for its efficiencies in terms of rice separation and de-stoning, the tray loss and impurity level after separation were also evaluated. The highest de-stoning efficiency was recorded between 5 to 7 mm feed gatesas 99.75 % and the lowest was recorded at a feed gate of 20 mm as 82.5 %. The highest rice separation efficiency was recorded at 5 mm feed gate to be 98.89 % and the lowest of 93.33 % was at 20 mm. The highest values of impurity level and tray loss were recorded at 20 mm as 2.041 % and 6.67 % respectively, while it lowest values were recorded at 5 mm as 0.028 % and 1.11 % respectively. The capacity also increased as the feed gate increase

Efficacy of expanded polystyrene as fine aggregate in cement mortars modified with latex paint as an alternative to polymer admixture

In this present study, the effectiveness of expanded polystyrene (EPS) waste used as 20, 40 and 60% fine sand replacement in development of lightweight cement composite was evaluated. The cement mortar was strengthened by 10% low cost latex paint emulsion as an alternative to the more expensive polymer admixtures. Six different mix designs were produced and tested for compressive and split tensile strength according to BS EN standards. Scanning electron microscope (SEM) analysis was also conducted to analysis the micrograph of the samples. It was observed that as the EPS content, latex paint polymer admixture and curing days were increased, marginal increment in compressive strength was obtained. However, EPS fines were most effective in improving the split strength while latex paint admixture had comparatively less part to play in the strength development. The micrograph images showed that the EPS fines were uniformly distributed within the microstructure and the latex paint developed polymer films. These mechanisms coupled with the cement hydrate products were responsible for the enhanced strength observed in the samples