Simulation and Optimization of Coal Gasification in a Moving-bed Reactor to Produce Synthesis Gas Suitable for Methanol Production Unit

This paper presents process simulation and optimization of coal gasification process in a moving-bed reactor using Pittsburgh No. 8 coal as feed. The system of differential equations for the mass and energy balances was solved using 4th-order Runge-Kutta method and optimized by non-dominated sorting genetic algorithm-II (NSGA-II) method. The simulation was used to predict solid and gas temperature profile and gas composition along the reactor. The simulation results were compared successfully with experimental data relevant to Westfield plant in Scotland. In addition, the effect of operating parameters such as coal-to-oxygen molar ratio, steam-to-oxygen molar ratio, inlet gas temperature, reactor pressure, and oxygen mole fraction in inlet air on amount of synthesis gas (syngas) production, hydrogen to carbon monoxide molar ratio (HCMR) in produced syngas, and coal conversion was investigated. Finally, the reactor performance was optimized to produce the highest syngas production with a HCMR of two using NSGA-II method. This work is licensed under a Creative Commons Attribution 4.0 International License

An Assessment of the University Usage of Social Media Platforms: Case from Lebanon—Theoretical Foundations—Part 1

This paper, part of two, aims to assess how a selection of Lebanese Universities utilizes social media platforms to attract potential student candidates. Social Media is considered a significant recruitment tool universities use to attract high school graduates from the millennium digital generation. Different universities have dealt differently with social media, so capturing recorded activity is essential to assess such efforts and pinpoint gaps to justify student recruitment investments by universities. This study uses a mix of quantitative and qualitative methods. A descriptive comparative analysis is carried out based on collected data from the different university social media platforms to help categorize selected universities in their efforts, successes, and gaps. However, this paper, the first part of two, represents the theoretical foundations needed for the study. Paper part two (2) will follow to illustrate the numerical and graphical analysis. Results show a lack of motivation schemes to attract potential candidates and encourage them to interact with such platforms. Moreover, universities lack specialized digital marketing staff to produce the appropriate content and design marketing strategies that are attractive, interactive, and with high response rates to inquiries

Evaluation of Yield of Wells in Ado-Ekiti, Nigeria

Pumping tests were conducted on twenty selected boreholes and five hand-dug wells cut across Ado Ekiti Metropolitan (AEM) area, with the view to ascertain yield of the wells. Constant rate pumping test and recovery method test were carried out. It was revealled that discharge is directly proportional to the yield of the boreholes and hand-dug wells at a constant drawdown, hence the discharge rate  gives the yield of each of the selected boreholes. The borehole depth ranges between 40 – 120 m while hand-dug well ranges between 3 – 15m. Borehole yield in the AEM area ranged between 0.267 l/s and 2.0 l/s. The yield was not totally dependent on the depths, but also on such parameters as porosity and permeability.  The potential of groundwater in AEM as it relates to quantity is high as all wells yielded water. The average water consumption in litres per person per day for high class income earners was estimated at 196 l/d, while that of low class income earners was 119 l/d. Most residence in AEM depend on ground water for domestic water demand. Possible improvement strategies to groundwater exploitation were highlighted. These improvement strategies and remedies are predrilling geophysical survey before siting of boreholes, monitoring groundwater exploration to avert depletion of groundwater potential zones encouraging sufficient recharge period and conducting regular laboratory tests. Keywords: yield, boreholes, hand-dug wells, recharge, Ado Ekiti

Secondary prevention after cerebral ischaemia of presumed arterial origin: is aspirin still the touchstone?

Patients who have had a transient ischaemic attack or nondisabling ischaemic stroke of presumed arterial origin have an annual risk of death from all vascular causes, non-fatal stroke, or non-fatal myocardial infarction that ranges between 4% and 11% without treatment. In the secondary prevention of these vascular complications the use of aspirin has been the standard treatment for the past two decades. Discussions about the dose of aspirin have dominated the issue for some time, although there is no convincing evidence for any difference in effectiveness in the dose range of 30-1300 mg/day. A far greater problem is the limited degree of protection offered by aspirin: the accumulative evidence from trials with aspirin alone and only for cerebrovascular disease of presumed arterial origin as qualifying event indicates that a dose of aspirin of at least 30 mg/day prevents only 13% of serious vascular complications

Simulating and Optimizing Hydrogen Production by Low-pressure Autothermal Reforming of Natural Gas using Non-dominated Sorting Genetic Algorithm-II

Conventional hydrogen production plants consist of natural gas steam reforming to CO+3H2 on Ni catalysts in a furnace, water-gas shift reaction for converting CO into CO2 and CO2 absorption. A new alternative method for highly endothermic steam reforming is autothermal reforming (steam reforming with air input to the reactor) without the need for external heating. In this study, hydrogen production by autothermal reforming for fuel cells (base case) was simulated based on a heterogeneous and one-dimensional model. In addition, the effect of operating variables on the system behavior was studied. Finally, Pareto-optimal solutions for the maximum molar flow rate of the produced hydrogen and methane conversion were determined by NSGA-II. There was a huge increase in the produced hydrogen molar flow to the base case, which showed the importance of optimizing autothermal reformers for hydrogen production

Forensic Analysis of WhatsApp SQLite Databases on the Unrooted Android Phones

WhatsApp is the most popular instant messaging mobile application all over the world. Originally designed for simple and fast communication, however, its privacy features, such as end-to-end encryption, eased private and unobserved communication for criminals aiming to commit illegal acts. In this paper, a forensic analysis of the artefacts left by the encrypted WhatsApp SQLite databases on unrooted Android devices is presented. In order to provide a complete interpretation of the artefacts, a set of controlled experiments to generate these artefacts were performed. Once generated, their storage location and database structure on the device were identified. Since the data is stored in an encrypted SQLite database, its decryption is first discussed. Then, the methods of analyzing the artefacts are revealed, aiming to understand how they can be correlated to cover all the possible evidence. In the results obtained, it is shown how to reconstruct the list of contacts, the history of exchanged textual and non-textual messages, as well as the details of their contents. Furthermore, this paper shows how to determine the properties of both the broadcast and the group communications in which the user has been involved, as well as how to reconstruct the logs of the voice and video calls. Doi: 10.28991/HIJ-2022-03-02-06 Full Text: PD

An Assessment of the University Usage of Social Media Platforms: Case from Lebanon—Analytics—Part 2

This paper, the second part of two, aims to provide results and findings to support the main objective of the research, i.e., to assess how a selection of Lebanese Universities utilizes social media platforms to attract potential student candidates. Social Media in the last decade has become a significant recruitment media adopted by universities around the globe, including Lebanon, to attract and effectively recruit millennial high school graduates who are digitally proficient and smart. Six universities were involved, so capturing recorded activity is essential to assess such efforts and pinpoint gaps that must be addressed to justify student recruitment investments by universities. This study is based on a mixed approach though with a concentration on the quantitative, deductive, and descriptive approaches capitalizing on collected data from the different university social media platforms and performing the required analysis to help categorize selected universities in their efforts, successes, and gaps. This paper shows the numerical, graphical, and discussion analyses of the results. Results confirm there is a lack of motivation schemes to attract potential candidates and encourage them to interact with such platforms. Moreover, universities lack specialized digital marketing staff to produce the appropriate content and design marketing strategies that are attractive, interactive, and with high response rates to inquiries

Technical Analysis: Exploring MACD in the Lebanese Stock Market

The stock markets have shown a great growth in the financial world that required traders to deal with many quantitative methods to analyze markets in order to predict commodities’ future prices. This study assesses the effect of technical analysis on the Lebanese stock markets by using a tool known as the Moving Average Convergence/Divergence (MACD) oscillator that explores how MACD can be utilized to optimize profits in the Lebanese stock exchange, during the trading process. The study is performed on closing prices of shares of six Lebanese banks and a real estate company, over a time period extending from the beginning of the year 2004 till the end of the year 2014. Results are meant to indicate whether MACD is able to optimize profits and forecast the Lebanese stock prices. It is concluded that the application of MACD in the decision making process for investing in the Lebanese stock market does not significantly contribute to the maximization of profitability on investments

An Assessment of Students’ Preferences Using Social Media Platforms on Their Selection of Private Universities in Lebanon

This paper assesses the behavior of prospective students of private universities in Lebanon on social media platforms; classifies them according to the extent and the way they use these platforms, and investigates students’ preferences using social media to choose a private University. A quantitative approach was adopted using a structured questionnaire administered to a convenient sample of 527 students from private universities in Lebanon who responded willingly. Collected data were analyzed using the SPSS program employing descriptive statistics. The university sample consisted of six Lebanese Higher Education Institutions that belong to different socio-economic categories, diverse cultures, many geographic locations, and varying chronological seniority. Results showed the influence of university pages on these platforms on students’ decisions and their adoption as a primary source of information before making their choices. Universities were unsuccessful in providing an effective communication channel with students or enabling two-way communication and motivating participation in comments, content creation, sharing experiences related to the universities, or sharing posts from their pages. Authors recommend universities review their motivational schemes for students to interact on university platforms regarding access to information and communication. For marketing, it is necessary to hire qualified staff, and provide a consistent and updated policy