Optimizing time of use (ToU) electricity pricing in regulated market

Time-of-Use (ToU) electricity price for residential consumers is receiving lots of attention lately with the increment of smart meters usage among residential customers. ToU prices reflect the actual electricity cost and the rate is commonly set base on market price of electricity. Implementing ToU pricing system on a regulated electricity system such as in Malaysia is complicated due to non existence of electricity market. The electrical utility company or the regulator will need to determine the optimum ToU prices that would give the correct price signal so that customers will react accordingly. Many factors need to be considered such as impact on electricity generation cost, load profile, load elasticity and customers’ satisfaction. This paper presents an optimization method to estimate the optimum ToU prices for given electricity demand profile and demand elasticity. The presented method able to reduce the gap between peak and off-peak demand and ensure the estimated ToU prices are fairly proportionate among hours i.e. summation of rate increments (from the fixed price) is equal to the summation of rate decrements. A simple system is used as a case study to demonstrate the application of the optimization method presented

Comparative study of selected indoor concentration from selective laser sintering process using virgin and recycled polyamide nylon (pa12)

Additive manufacturing (AM) stands out as one of the promising technologies that have huge potential towards manufacturing industry. The study on additive manufacturing impact on the environment and occupational exposure are attracting growing attention recently. However, most of the researcher focus on desktop and fused deposition modelling type and less attention given to the industrial type of AM. Usually, during the selective laser sintering process, recycle powder will be used again to reduce cost and waste. This article compares the PM 2.5, carbon dioxide (CO2) and total volatile organic compound (TVOC) concentration between virgin and recycles powder using polyamide-nylon (PA12) towards indoor concentration. Four phases of sampling involve during air sampling accordingly to the Industry Code of Practice on Indoor Air Quality 2010 by DOSH Malaysia. It was found that PM 2.5 and CO2 concentration are mainly generated during the pre-printing process. The recycle powder tended to appear higher compared to virgin powder in terms of PM 2.5, and CO2. The peak value of PM 2.5 is 1452 μg/m3 and CO2 is 1218 ppm are obtained during the pre-printing process during 8 hours of sampling. TVOC concentration from recycling powder is slightly higher during the post- printing phase where confirm the influence of the powder cake and PA12 temperature from the printing process. In summary, this work proves that elective laser sintering (SLS) machine operators are exposed to a significant amount of exposure during the SLS printing process. Mitigation strategies and personal protective equipment are suggested to reduce occupational exposure

Morphology and composition of strontium calcium aluminate matrix doped with Dy3+

The aim of the present study was to determine the influence of doping rare earth ion on strontium calcium aluminate (CaO-SrO-SiO2-Al2O3). Therefore, the authors have manufactured luminescent material consisting of 40CaO-5SrO-5SiO2-50Al2O3 doped with Dy3+. The compositions have been selected on the basis of chemical stability. Five pellets were prepared with different calcination temperatures and times, namely 400 and 600°C for 1 and 2 h, in order to shed light on their luminescence behaviour. X-ray diffraction, energy dispersive X-ray analysis and scanning electron microscopy elaborate and characterise the formation of small particle of photoluminescent material in the phosphor matrix host material

Modeling And Simulation Of Wind Turbine For Partial Load Operation

The purpose of this research is mainly to model a wind turbine with doubly fed induction generator (DFIG) and to investigate its behavior in partial load operation using computer simulation. System behavior analysis and simulation are two particular approaches applied in this research. The wind turbine model is developed whereby the behavior of its main components is described by mathematical model and transformed in simulation model in MATLAB/Simulink. The simulation model is carried out in partial load operation at a wind speed of 9 m/s. The physical quantities including generator speed, torque and electrical power output are measured and evaluated. By using variable speed generator, a wind turbine model with optimum power generation at wind speed between 4 m/s to 13 m/s is created. This research shows that if mathematical models represent the wind turbine accurately, then the proposed model can be used to observe the dynamic behavior of wind turbine precisely, efficiently and inexpensively. The simulation result is expected to be a reference for extending the knowledge of dynamic behavior of wind turbines and optimize the performance of future large-scale wind turbine systems

Isolation and characterization of an SDS-degrading Klebsiella oxytoca.

Sodium dodecyl sulfate (SDS) is one of the main components in the detergent and cosmetic industries. Its bioremediation by suitable microorganism has begun to receive greater attention as the amount of SDS usage increases to a point where treatment plants would not be able to cope with the increasing amount of SDS in wastewater. The purpose of this work was to isolate local SDS-degrading bacteria. Screening was carried out by the conventional enrichment-culture technique. Six SDS-degrading bacteria were isolated. Of these isolates, isolate S14 showed the highest degradation of SDS with 90% degradation after three days of incubation. Isolate S14 was tentatively identified as Klebsiella oxytoca strain DRY14 based on carbon utilization profiles using Biolog GN plates and partial 16S rDNA molecular phylogeny. SDS degradation by the bacterium was optimum at 37 degrees 0. Ammonium sulphate; at 2.0 g l(-1), was found to be the best nitrogen source for the growth of strain DRY14. Maximum growth on SDS was observed at pH 7.25. The strain exhibited optimum growth at SDS concentration of 2.0 g l(-1) and was completely inhibited at 10 g l(-1) SDS. At the tolerable initial concentration of 2.0 g l(-1), almost 80% of 2.0 g l(-1) SDS was degraded after 4 days of incubation concomitant with increase in cellular growth. The K(m(app) and V(max(app)) values calculated for the alkylsulfatase from this bacterium were 0.1 mM SDS and 1.07 micromol min(-1) mg(-1) protein, respectively

Conformally parametrized surfaces associated with CP^(N-1) sigma models

Two-dimensional conformally parametrized surfaces immersed in the su(N) algebra are investigated. The focus is on surfaces parametrized by solutions of the equations for the CP^(N-1) sigma model. The Lie-point symmetries of the CP^(N-1) model are computed for arbitrary N. The Weierstrass formula for immersion is determined and an explicit formula for a moving frame on a surface is constructed. This allows us to determine the structural equations and geometrical properties of surfaces in R^(N^2-1). The fundamental forms, Gaussian and mean curvatures, Willmore functional and topological charge of surfaces are given explicitly in terms of any holomorphic solution of the CP^2 model. The approach is illustrated through several examples, including surfaces immersed in low-dimensional su(N) algebras.Comment: 32 page

Optimisation and growth kinetic analysis of Microalgae, Arthrospira platensis in 2-L Photobioreactors

In recent years, photoautotrophic microalgae are widely recognised due to their diverse yet significant natural values, particularly in healthcare, including pharmaceuticals, cosmetics and feedstock industries. One of the most exploited blue-green microalgae, Arthrospira sp. has been addressed as a potent superfood. However, the microalgal mass-production requires suitable inoculum strain and controlled cultivation conditions for enhanced growth performance. Hence, this study aimed to maximise biomass of Arthrospira platensis chosen strain in a 2 litres indoor photobioreactor under three different parameters which were aeration rate, light intensity and pH of the medium. In the present study, a comparative study of growth performance between helical (S1) and straight form (S2) of A. platensis was conducted and the results revealed that morphological differences did not affect growth performances. Meanwhile, the optimisation based on the parameters studied shows that cultivation of A. platensis with aeration of 0.5 L/min and medium of pH 9.0 yielded the highest biomass production which were 1.500 0.049 g/L. Under different light intensity, A. platensis produced the highest biomass and maximum specific growth rate of 1.142 0.037 g/L and 0.716 0.018 1/day, respectively when cultivated under irradiance of 6000 Lux. In conclusion, compared to before optimisation, biomass and maximum specific growth rate after optimisation was 137% and 24% increased, respectively

Supersymmetric version of a Gaussian irrotational compressible fluid flow

The Lie point symmetries and corresponding invariant solutions are obtained for a Gaussian, irrotational, compressible fluid flow. A supersymmetric extension of this model is then formulated through the use of a superspace and superfield formalism. The Lie superalgebra of this extended model is determined and a classification of its subalgebras is performed. The method of symmetry reduction is systematically applied in order to derive special classes of invariant solutions of the supersymmetric model. Several new types of algebraic, hyperbolic, multi-solitonic and doubly periodic solutions are obtained in explicit form.Comment: Expanded introduction and added new section on classical Gaussian fluid flow. Included several additional reference

Graphene nanoplatelets (GnP)-PVA based passive saturable absorber

We demonstrate a passive Q-switched at 1.5 μm region by integrating a graphene nanoplatelets (GnPs) embed in Polyvinyl Alcohol (PVA). The GnPs was dispersed with the aid of surfactant and mixed with PVA by solution casting aroach and then dried at ambient temperature to develop a GnPs-PVA film. The integration of the passive Q-switcher is by attaching a small portion of the developed GnPs-PVA film at the end of fiber ferrule in the laser cavity with ring configuration to generate pulse laser. The experimental works show that the proposed GnPs-PVA film based passive Q-switcher operates at input pump power ranges from 39 mW to 148 mW with central wavelength of 1530.76 nm. We observe the tunable repetition rate from 33 kHz to 91.5 kHz with the shortest pulse width of 2.42 μs. The laser produce maximum instantaneous output peak power and pulse energy of 1.2 mW and 5.9 nJ, with the recorded signal to noise ratio of 28 dB