The benefits of the transition from fossil fuel to solar energy in Libya: A street lighting system case study

The Libyan economy is dominated by the oil and the gas industry which are considered as the primary energy sources for the generating power plants. With the increased energy demands in the near future, Libya will be forced to burn more oil and gas. This, in turn will result in reducing the country revenue, threatening the economy and increasing the CO₂ emission. This triggers the alarm for Libya to an urgent plan to diversify the energy sources through using sustainable energy. The sun showers Libya every day by a huge amount of sunshine, especially during the peaks in the summer days. Recently, the country has been struggling to satisfy its escalating energy demands. The residential and street lighting loads constitute more than 50% of the electricity demands in Libya. Street lighting consumes more than 3.996 TW h, which is around one fifth of the energy demands in Libya. Energy conservation and transition from fossil fuel to renewable energy could have significant profit on the energy sector in Libya. For example, Libya is still relying on the old-fashioned, inefficient and unsustainable street lighting systems. Replacing the old technology lighting systems with up-to-date solar powered lighting system can achieve energy saving and sustainability. In this paper, improving the energy situation in Libya through replacing the high pressure sodium street lighting systems with solar powered LED street lighting systems is investigated. A four km road is chosen as a case study. Four alternatives are analyzed; grid-powered high pressure sodium lamp street lighting system, grid-powered LED lamp street lighting system, stand-alone solar powered LED street lighting system and grid-connected solar powered LED street lighting system. The four options are compared in terms of the capital cost, maintenance cost, total cost, fuel cost and the CO₂ emission. Replacing the high pressure sodium lamp system with LED lamp system saves 75% of energy and reduces the CO₂ emission by 75%. The stand-alone solar powered LED lighting system cuts the CO₂ emission, saves the fuel and is economically feasible. Furthermore, improvement is attained if the solar powered lighting system is connected to the grid where the excess energy is fed to the grid. The two solar powered options are economically feasible and sustainable.     

Improved Slime Mould Algorithm based on Firefly Algorithm for feature selection: A case study on QSAR model

Feature selection (FS) methods are necessary to develop intelligent analysis tools that require data preprocessing and enhancing the performance of the machine learning algorithms. FS aims to maximize the classification accuracy by minimizing the number of selected features. This paper presents a new FS method using a modified Slime mould algorithm (SMA) based on the firefly algorithm (FA). In the developed SMAFA, FA is adopted to improve the exploration of SMA, since it has high ability to discover the feasible regions which have optima solution. This will lead to enhance the convergence by increasing the quality of the final output. SMAFA is evaluated using twenty UCI datasets and also with comprehensive comparisons to a number of the existing MH algorithms. To further assess the applicability of SMAFA, two high-dimensional datasets related to the QSAR modeling are used. Experimental results verified the promising performance of SMAFA using different performance measures.

     

Modelling the properties of pigment‐printed polypropylene nonwoven fabric using the Box–Behnken technique

The aim of this study was to develop statistical models for the effect of binder concentration and curing temperature and time on the air permeability, tear strength, tensile strength, and crocking fastness of pigment‐printed nonwoven polypropylene fabric. The design and analysis of the experimental work were carried out using Minitab ^® statistical software according to the Box–Behnken design of response surface methodology. Models were successfully developed. It was found that binder concentration improves the wet crocking and tensile strength while having a negative impact on all other responses. Increase in curing temperature and time affects the fabric tear strength negatively but has a positive effect on wet crocking fastness and fabric tensile strength. It could be concluded that pigment prints of good dry crocking fastness may be obtained on polypropylene nonwovens without deterioration in the mechanical strength and air permeability to a commercially unacceptable level. However, further work is required to improve the wet crocking fastness properties.     

含离子液体溴化1-丙基-3-甲基咪唑的二元和三元体系的蒸气压测定

Vapor pressure values of binary systems water ＋ ethanol, water ＋ ionic liquid 1-propyl-3- methylimidazolium bromide （[PMIM] [Br]）, ethanol ＋ [PMIM] [Br] and ternary system water ＋ ethanol ＋ [PMIM] [Br] at different temperatures were measured by using a modified boiling point method in various concentrations of （16.66%, 33.7%）, （17.4%, 33.9%） and （16.5%, 32%） mass percent of ionic liquid, respectively. The experimental vapor pressures of solvent were well correlated by the Antoine-type equation, and the overall average absolute deviation （AAD） was found to be 0.39%. The experimental results for mixtures containing ionic liquid indicate that the vapor pressure of the solvents can be decreased noticeably to different extent due to the affinity difference between ionic liquid and solvent, which is similar to the salt effect of common inorganic salts. As a result, ionic liquid may find industrial applications in extractive distillations for the system with a low separation factor or even for an azeotropic mixture.     

New transformed features generated by deep bottleneck extractor and a GMM–UBM classifier for speaker age and gender classification

Neural Computing and Applications - Speaker age and gender classification is one of the most challenging problems in speech signal processing. Recently with developing technologies, identifying...     

Optimal Scanning Protocols for Dual-Energy CT Angiography in Peripheral Arterial Stents: An in Vitro Phantom Study

Objective: To identify the optimal dual-energy computed tomography (DECT) scanning protocol for peripheral arterial stents while achieving a low radiation dose, while still maintaining diagnostic image quality, as determined by an in vitro phantom study. Methods: Dual-energy scans in monochromatic spectral imaging mode were performed on a peripheral arterial phantom with use of three gemstone spectral imaging (GSI) protocols, three pitch values, and four kiloelectron volts (keV) ranges. A total of 15 stents of different sizes, materials, and designs were deployed in the phantom. Image noise, the signal-to-noise ratio (SNR), different levels of adaptive statistical iterative reconstruction (ASIR), and the four levels of monochromatic energy for DECT imaging of peripheral arterial stents were measured and compared to determine the optimal protocols. Results: A total of 36 scans with 180 datasets were reconstructed from a combination of different protocols. There was a significant reduction of image noise with a higher SNR from monochromatic energy images between 65 and 70 keV in all investigated preset GSI protocols (p < 0.05). In addition, significant effects were found from the main effect analysis for these factors: GSI, pitch, and keV (p = 0.001). In contrast, there was significant interaction on the unstented area between GSI and ASIR (p = 0.015) and a very high significant difference between keV and ASIR (p < 0.001). A radiation dose reduction of 50% was achieved. Conclusions: The optimal scanning protocol and energy level in the phantom study were GSI-48, pitch value 0.984, and 65 keV, which resulted in lower image noise and a lower radiation dose, but with acceptable diagnostic images.     

Simulation and experimental studies of corona power loss in a dust loaded wire-duct electrostatic precipitator

This paper investigates numerically and experimentally the performance of a single stage wire-duct electrostatic precipitators (WDEP) as influenced by different geometrical and operating parameters. To numerically solve the governing equations, namely Poisson’s and the current continuity equations, the finite element method (FEM) and a modified method of characteristics (MMC) were used. One major advantage of the present work over those reported in the literature is that the characteristic lines follow the FE grid pattern which results in fast convergence and reduction of the computational time. To verify the results experimentally, a proto-type WDEP was successfully designed and fabricated at the research institute of KFUPM (RI-KFUPM). The experiments were carried out under laboratory conditions and a smoke of fired coal was used as a source of seed particles of PM10 category (around 78% of particles lying below 10 μm). The results show how different parameters (such as discharging wire radii’s, wire-to-wire spacing and wire-to-plate spacing as well as the fly ash flow speed and applied voltage polarity) influenced the corona power loss and current density profiles. An indication of the effectiveness of this approach was carried out through a comparison of previously computed results and previously as well presently obtained experimental data.     

Unpacking the black-box of students' visual attention in Mathematics and English classrooms: Empirical evidence using mini-video recording gadgets

With the technological improvements of innovative portable recording gadgets, augmented researchers' interest in exploring students' visual attention in their natural and normal occurring classrooms. The purpose of this study was to gauge students' visual attention in their Mathematics and English classrooms. This article reports on a study conducted in three schools in Santiago, Chile, where a sample of 113 randomly selected students wore a mini-video camera mounted on eyeglass in their Mathematics and English lessons. Using Google images, we automatically and objectively examined 723,600 frames from the recordings where the classroom teacher appeared in the students' visual field. The results show that students' visual attention varies depending on four factors: (a) gender of the student, (b) age of the students, whether students are low/high attainers and (d) whether students are in English or Mathematics lessons. Surprisingly, students significantly paid more visual attention in their Mathematics than in English lessons. High attainers were more visually engaged than their low attainers counterparts. Students appeared to be visually engaged differently at different stages in their education. Furthermore, girls were more visually engaged than boys. The results of this study can have enormous practical implications for teachers and teacher education, in order to be better visually engaged with students during teaching.     

Determination of Vapor Pressures for Binary and Ternary Mixtures Containing Ionic Liquid 1-propyl-3-methylimidazolium Bromide

Vapor pressure values of binary systems water + ethanol, water + ionic liquid 1-propyl-3-methylimidazolium bromide ([PMIM][Br]), ethanol + [PMIM][Br] and ternary system water + ethanol + [PMIM][Br] at different temperatures were measured by using a modified boiling point method in various concentrations of (16.66%, 33.7%), (17.4%, 33.9%) and (16.5%, 32%) mass percent of ionic liquid, respectively. The experimental vapor pressures of solvent were well correlated by the Antoine-type equation, and the overall average absolute deviation (AAD) was found to be 0.39%. The experimental results for mixtures containing ionic liquid indicate that the vapor pressure of the solvents can be decreased noticeably to different extent due to the affinity difference between ionic liquid and solvent, which is similar to the salt effect of common inorganic salts. As a result, ionic liquid may find industrial applications in extractive distillations for the system with a low separation factor or even for an azeotropic mixture.