Abstract— The continual search for alternative environmentally cleaner technologies in industrial processes has led to an increase in the use of enzymatic processes globally. However, due to their physical characteristics they require immobilization in order to remain effective. The objective of this study was to investigate the immobilization of the biotechnologically important and commercially available Candida rugosa lipase (CRL) by physical interfacial adsorption onto a number of matrices to act as biocatalysts. Five different types of support were tested: i) macroporous silica (synthetic inorganic), ii) polyhydroxybutyrate (natural organic), iii) polypropylene (synthetic organic), iv) polymethacrylate (synthetic organic), and v) polystyrene-divinylbenzene (synthetic organic). Results generated during this study showed that from the group of materials tested, polystyrene-divinylbenzene gave the best results with the highest amount of immobilized protein (8.10 ± 0.31 mg/g) and a good immobilization yield (90.35% ± 1.53%). The efficiency of protein immobilization was found to be highest when carried out at pH4.5, which is close to the isoelectric point of the enzyme.
Keywords—Biocatalysts, Candida rugosa, immobilized protein, lipase, physical adsorption, support.
Kinetic Characteristics for Reaction between Trichloroisocyanuric (TCCA) Acid with 2-Chlorobenzylidene Malononitrile (CS)
Abstract— The research experimental results determiningrateconstant of the reaction between TCCA and CS according to Arrhenius equation was studied. Basing the set of graphs showing the relationship between (ln(k) – (1/T)) and (ln (k/T) – (1/T)), the activation energy (Ea) according to the Arrhenius equation and activation enthalpy variation (∆H#), activationentropy variation (∆S#), free activation energy Gibss (∆G#) according to the Eyring equation are determined. The products of TCCA reaction and CS at pH = 9 are2-chloro benzaldehyde oxirane-2,2-dicarbonitrile, 3-(2-chlorophenyl) so predicting the reaction mechanism consists of two reactions taking place in parallel, a hydrolysisand oxidation reactions.
Keywords— Trichloroisocyanuric acid, 2-chlorobenzylidene malononitrile, Kinetic characteristics.
Design Parameters and Conceptual Analysis on Gas Resource and Infrastructure Management: Trans-Nigeria Gas Pipeline Projects in Nigeria
Abstract— Gas pipeline network and indeed gas infrastructures in the industry are liken to arteries and veins of the body. Blood circulation in the body systems travels through arteries and veins while gas resource travel through network of pipes for industrial and domestic purposes. Nigerian dependency on oil in the last 50years, has been characterised with reserves depletion and infrastructural decays. Therefore, the urgent intervention for Gas Domestication Project cannot be over emphasised. There are endless investment opportunities that abound in the natural gas sector of the Nigerian petroleum industry. At present, the annual gas production in Nigeria is about 2000 BSFC which is remarkable for an oil dominated economy (Figures 1, 2 and 3). Therefore, the initiatives for sustainable gas domestication projects such as the Calabar -Umuahia – Ajaokuta (CUA) and the Ajaokuta – Abuja – Kano (AAK) are laudable in terms of boosting economic resources for future investments. The rapid quests for industrial development of the country necessitate the conceptualization of the Trans Nigerian Gas Pipeline Projects. The project was divided into two segments the Calabar – Umuahia – Ajaokuta (CUA) trunk and the Ajaokuta – Abuja – Kaduna –Kano (AAK) trunk line respectively. The CUA is a 681km, 56” underground single-phase pipeline while the AAK is a 585km, 56” underground single-phase pipeline respectively. The spur lines were design to withstand maximum of 24”and minimum of 22”respectively. The entire project cycle from conceptualization, design and completion were undertaken within two years with about eighty-five (85%) per cent Nigerian Content. The Nigerian engineers and scientists in collaboration with the consultants, deliver the project on schedule (Table 1). The implementation strategy was predicated on the utilization of Critical Path Method (CPM) and Site Man-hour and Cost Control (SMAC) approach for project scheduling, monitoring and evaluation as well as cost control activities all through the duration,(Equations 1-6). Risk determination and safety checks were carried out at each stage for Environmental Impact Assessment (EIA), Front End Engineering Design (FEED), Detailed Engineering Design (DEED), Hazop and Hazid Safety processes, Helicopter Overfly and Right of way Mapping, Cost and Constructability Review and Invitation To Bid (ITB) documentation etc were scheduled and completed. Timely completion of the engineering design and documentation of the project was fundamental to the procurement and construction of the pipeline network. Procurement and construction work schedule are expected to increase industrial development of the country. Efficient gas utilization through gas to power projects, industrial parks along the gas pipeline routes is also affected. This study is expedient in the actual analysis and review of the initial engineering design and safety codes with a view to ensuring compliance with industry standards. The study is also significant as reference material for the actualization of the vision of designing and constructing a world class Trans-Nigerian gas pipeline projects. It will also serve asa reference material for administrators and decision makers on effective deployment and management of resources on gas pipeline projects in Nigeria.
Keywords— Conceptual Analysis, Critical Path Method, Site Man Hour and Cost Control, Infrastructure Management, Right-of-Way, Design Parameters, Environmental Impact Analysis.
Abstract—Poly(dimethyl siloxane) (PDMS) microspheres are increasingly gaining importance for a wide range of applications due to their flexibility and inertness. In this paper, we have fabricated PDMS microspheres using facile emulsion formation in water by stirring with and without additional ultrasonic excitation. It was found that the particle size distribution, which can be attributed to the formation rate of cross-linked PDMS networks in the hydrophobic microspheres, depends on the temperature of the aqueous medium. Swelling of the microspheres in acetone was suggested by permeabilization as evidenced by diffusion and encapsulation of fluorescent dyes within the PDMS. Using scanning electron microscopy, the surface morphology of the spheres was confirmed to have no surface roughness or irregularity. Using fluorescence microscopy, we found that the encapsulated dyes randomly and thus uniformly distributed themselves within the cross-linked PDMS networks and retained the fluorescent properties and characteristic emission color, implying their potential for drug carrier.
Keywords—poly(dimethyl siloxane) (PDMS), microspheres, swelling, encapsulation, fluorescent dyes.