Proton exchange membrane fuel cells (PEMFC) are increasingly becoming an attractive energy source for the future due to their portability, silent operation and high power density. Efforts have been made to improve their efficiency as well as in making the technology affordable. Several parameters come into play in the context of fuel cell efficiency, of which the operating temperature is of prime importance. Specifically, high temperature PEM fuel cell (HTPEMFC) has greater merits such as higher efficiency, improved tolerance of the electrodes against carbon monoxide poisoning, faster reaction kinetics, and effective heat transfer. Since the proton conductivities of commonly used perfluorinated membranes, such as Nafion, is highly dependent on external humidification, their operating temperature is limited to 100 °C. Hence one of the biggest challenges in PEMFC is fabricating a thermally stable membrane which can operate at temperatures above 100 °C under anhydrous conditions.

In the present work phoshonated SBA-15/phosphonated Poly(styrene-ethylene-butylene-styrene) (PSEBS) composite membranes are developed for high temperature fuel cell electrolyte. Mesoporous Santa Barbara Amorphous (SBA-15) was synthesized and it was grafted with phosphonate functionality using a simple two-step process involving chloromethylation and subsequent phosphonation. The phosphonated SBA-15 (PSBA-15) was characterized using Fourier transform infra-red (FTIR) spectroscopy, solid state ¹³C Nuclear magnetic resonance (NMR), ²⁹Si NMR, ³¹P NMR for confirming successful modification. Morphology features were verified by small angle X-ray diffraction (XRD), Scanning electron microscopy (SEM) and Transmission electron microscopy TEM analyses. Poly(styrene-ethylene-butylene-styrene) (PSEBS) was chosen as the base polymer and phosphonic acid functional groups were grafted onto the polymer using the aforementioned approach, where chloromethyl (-CH₂Cl) groups were attached to the main chain using Friedel Craft’s alkylation, followed by the phosphonation of the chloromethylated polymer by the Michaels-Arbuzov reaction resulting in phosphonated PSEBS (PPSEBS). The functionalisation was confirmed using NMR and FTIR spectroscopy studies. Composite PPSEBS/PSBA-15 membranes were fabricated with different filler concentrations (2, 4, 6, and 8%) of PSBA-15. Various studies such as water uptake, ion exchange capacity and the proton conductivity of the composite membranes were undertaken with respect to fuel cell applications. From the studies, it was found that the PPSEBS/PSBA-15 membrane with 6% wt of filler exhibited maximum proton conductivity of 8.62 mS/cm at 140 °C. Finally, membrane electrode assembly (MEA) was fabricated using PPSEBS/6% PSBA composite membrane, Platinium (Pt) anode, Pt cathode and was tested in an in-house built fuel cell setup. A maximum power density of 226 mW/cm² and an open circuit voltage of 0.89 V was achieved at 140 °C under un-humidified condition.

Wide-scale deployment of Smart Inverters (SIs) can only happen if their impacts on power systems can be clearly understood. For this reason, thorough power flow and system stability studies are required. Traditional power system simulation software does not include proper models for SIs. Furthermore, dynamic behavior of SIs is not very well known to develop such models. Consequently, hardware in the loop tests with digital real-time simulators seem to be the best option, due to their high fidelity. That being said, interface between the simulated and real-world plays a very significant role. Since the real world is sampled and these samples are utilized to map reality inside digital real-time simulator, any mistake may render the test unstable. On the other hand, real-time simulation has very strong timing requirements and this becomes a deciding factor on how much detail can be modeled. Since the bridge inverters have several components that operate in time steps that are much smaller than conventional power systems, digital real-time simulators have very limited capacity. Using simplified inverter models has been investigated in the past and shown to be acceptable in steady-state situations. This paper investigates use of such models for protection studies in low-voltage networks.

Natural gas is considered as clean and efficient fossil energy and its consumption is increasing worldwide. Pipelines are widely used as the most economical means of transporting and distributing natural gas over short distances. The distribution pipelines are usually pressurized, and they may become disastrous when gas is accidentally released to the atmosphere. Also, natural gas is volatile and highly flammable, unintentional gas release in urban areas can lead to severe consequences and losses in society. Therefore, it is important to assess the risk of natural gas pipeline in urban areas. In this paper analysis of risks in different parts of the Dar es salaam Natural gas distribution network is conducted. Newton's nodal method was used to analyze the network and an integrated quantitative risk analysis method used to estimate incident losses. The results obtained are useful in understanding the risks, decisions making and taking measures towards ensuring the safety of Dar es salaam natural gas distribution pipeline.

Being simple and cost-effective, small wind turbines are mainly used as energy option for decentralized rural electrification in developing countries. Since installation site of small wind turbine is normally decided based on the areas where electrification is needed rather than where there is best wind resource, low wind speed sites can not be avoided. However, under low wind speed conditions, energy output has been found to be lower than one which can be predicted. Many researchers have attempted to identify the reasons for such low performance and suggest requisite improvement. Poor starting behavior has been found to be one of the major drawbacks of which there had been many attempts to improve it. Never the less, still commercial small wind turbines depict low performance in low speed wind regimes. In this paper, the rotor parameters responsible for enhancing turbine starting were analyzed and the results used in innovative processes to come up with the rotor having high starting torque and high maximum power performance. Unlike conventional rotor of the horizontal axis wind turbine, the rotor comprises of extra shorter blades mounted on same hub circumference. Blade Element Momentum theory was used to predict the power performance of the novelty rotor.

The Civil Liability for Nuclear Damage Act, 2010 follows global practice in the field of nuclear civil liability and has a specific provision that enables a nuclear operator to exercise right of recourse against a supplier. The Civil Liability for Nuclear Damage Rules, 2011 provides explanation regarding the provisions enshrined in the Act. The Rules explains about the Supplier which has been formulated based on the industry practices of nuclear sector. The paper analyses the Civil Liability for Nuclear Damage Act and Rules on the issue of compatibility of right of recourse with the international nuclear civil liability principles and conventions, particularly with the Convention on Supplementary Compensation for Nuclear Damage, 1997. This paper also discusses the issue of right of recourse by nuclear operator against the supplier in the light of explanation about a supplier as provided under the Act and Rules.

The aim of this work was to analyze inlet effect and patterns development length of the vertical gas-liquid flow experimentally. The study was conducted in multiphase rig with a test section of 18m long pipeline and 60 mm internal diameter. Two types of inlets were considered. Four conductivity probe rings were installed at four different positions along the test section. Water flow rate was kept at 0.07 m/s by adjusting pump frequencies and water inlet valve. Air was varied from 4 m/s to 22 m/s at atmospheric pressure and temperature so that to attain different types of flow pattern. Recognition of flow patterns was done by considering four methods; observation with aid of high-speed camera, time series of conductance signals, signals probability density functions and distribution moments about mean. Conductance signals were collected for about two minutes for each test after attaining steady state flow. The results show that with steady state flow, patterns transition can occur within a test section while the inlet effect is very small for slug propagation within a test section.

This research was performed in order to allow the study of the chemical composition influence of the coking process load on the efficiency and the quality of coke. For this reason, the coking of the following loads was realized: Atmospheric residue (RAT), vacuum Residue (RSV) and catalytic Residue of cracking (RCC). (The residues are obtained from an Algerian crude oil).As the oil residues are rich for their strongly polar composition, such as the asphaltene resins, and complex structures units (SCU), which has a role in the formation of coke, and as the dispersion of these latter improves the quality of coke, a study on the stability of aggregation was carried out by the addition of one stabilizer (oil Extract) in the coking process load. The Compounding (Extracted from /RCC oil) has been drived to the best efficiency of coke. The study consists of the influence, this is characterized by the analyses Infra-red (IR) and x-ray diffraction (XRD).