Failure of a Vertical Drainage System Installed to Fight the Rise of Groundwater in El-Oued Valley (SE Algeria): Causes and Proposed Solutions

El-Oued Valley suffers from the problem of rising groundwater which affects agricultural and urban areas and degrades all aspects of the socioeconomic life of its inhabitants. This problem, which appeared in the 1980s, is primarily a result of overexploitation of deep groundwater, lack of sanitation network, and discharge of wastewater directly into the unconfined aquifer. To solve this problem, a megaproject was carried out, based on the principle of sewerage, to drain and evacuate excess water after treatment to a discharge site 70 km north of the region. In this project, the blade of groundwater above elevation of 60 m should be drained through wells of a vertical drainage system. However, the expected results have not been achieved in most affected cities, where the groundwater level continues to rise. Herein, we propose a solution to this problem, based on a new explanation of the hydrogeological structure of the unconfined aquifer that drives the rising groundwater to the surface. The main part of this research is based on interpretation of well tests carried out in wells of the vertical drainage system.     

Adaptive stabilization of uncertain nonlinear time‐delay systems with quantized input and output

This paper investigates the problem of global output feedback stabilization for a class of uncertain nonlinear time‐delay systems with unknown time delay in the states and the input in which both the input and the output are logarithmically quantized. The nonlinear functions of such systems are not completely known and satisfying certain bounded condition depending on the unmeasured states and the input. We construct a new dynamic high‐gain observer where only an output quantization instead of the output is available for measurement to dominate the unknown nonlinear functions view as external disturbances. A scaled change of coordinates and an appropriate Lyapunov‐Krasovskii functional are derived to achieve the global stabilization in the sense that all the states of such systems are defined, bounded in the maximal interval [0, +∞), and converge to the zero equilibrium. A numerical example is provided to illustrate the result.     

Synthesis and Characterization of Polycarbonate/TiO2 Ultrafiltration Membranes: Critical Flux Determination

A novel polycarbonate (PC) membrane was modified with titanium dioxide via nonsolvent-induced phase separation method to improve its hydrophilicity and antifouling properties in a submerged membrane system for the removal of humic acid (HA) both with and without polyaluminum chloride (PAC) coagulant. The effect of TiO₂ additive on the morphology and performance of the nanocomposite membranes was studied by atomic force microscopy, field emission scanning electron microscopy, energy dispersive X-ray, mechanical properties, water contact angle, porosity, pure water flux, rejection tests, and antifouling parameters. The obtained results revealed that a higher critical flux was achieved by the PC/TiO₂ nanocomposite membrane. The flux recovery ratio of the neat PC membrane increased with the addition of TiO₂ nanoparticles and without PAC coagulant. HA removal for the PC nanocomposite membrane was higher than that of the neat PC membrane with and without PAC coagulant.     

Candidate architectures for emerging IoV: a survey and comparative study

Intelligent Transportation System (ITS) is observing significant evolution in terms of technology and investment worldwide. This has given birth to the new concept of Internet of vehicles (IoV) as one of the leading applications of the Internet of Things. IoV aims to offer a better sharing of information and communication between vehicles, enabling higher cooperation for common interests. IoV is increasingly attracting the interest of a significant body of research. The e ort was mostly focused on solving various problems encountered in traditional VANETs, such as lack of coordination between vehicles, insufficient information, scalability, etc. Rapidly, IoV observed, particularly interesting advances taking advantage of exponential growth in communication and data analysis technologies. This includes cloud and/or fog computing, large data analytics, machine learning, and artificial intelligence. In this paper, we make a survey of the existing and recently proposed architecture solutions for IoV systems. Moreover, we define a list of criteria, features, and properties associated to the various architectures in order of making critical and insightful comparisons and assessments. Finally, we outline the key future research perspectives on the topic and define the key technical aspects that will help drive the future of IoV architectures.

     

Pre-Silicon Verification Using Multi-FPGA Platforms: A Review

Because of the shrinking transistor size and improved design process, the computation capability of modern digital systems has increased tremendously over the past few years. This, however, has led to increased design complexity and huge verification efforts and costs. The design of new digital systems costs millions of dollars and the money is wasted if the final product does not serve the purpose. This has made pre-silicon verification even more pertinent as it can detect design faults prior to its roll out and can save companies a huge fortune. Pre-silicon verification now accounts for almost 70% of the total design effort and cost of modern digital systems. For pre-silicon verification, four techniques are commonly used namely simulation, emulation, virtual prototyping and FPGA-based prototyping. These techniques have their advantages and disadvantages. However, FPGA-based prototyping is unique in the sense it gives better speed and real world testing experience as compared to other pre-silicon verification techniques. In this paper, we give a detailed survey of multi-FPGA prototyping. A survey of three different multi-FPGA platforms namely off-the-shelf, custom, and cabling platform is presented in this work. A comprehensive overview of these platforms from hardware perspective is presented. Detailed discussion on their respective back end flow and the associated difference is also presented. The survey is concluded with a discussion on the challenges faced by multi-FPGA prototyping and the research opportunities where work can be done for further improvement.

     

Stress analysis of longwall top coal caving

Longwall top coal caving (LTCC) is a relatively new method of mining thick coal seams that is currently achieving high productivity and efficiency in application, particularly in China. The technique is similar to traditional longwall mining in that a cutting head slices coal from the lower section of the coal seam onto a conveyor belt installed in front of the hydraulic support near the cutting face. In modern LTCC an additional rear conveyor belt is located behind the support, to which the flow of the caved coal from the upper part of the seam can be controlled by a moveable flipper attached to the canopy of the support. The mining method relies on the fracturing of the top coal by the front abutment pressure to achieve satisfactory caving into the rear conveyor.This paper develops a yield and caveability criterion based on in situ conditions in the top coal in advance of the mining face (yield) and behind the supports (caveability). Yielding and caving effects are combined into one single number called caving number (CN), which is the multiplication result of caving factor (CF) and yield factor (YF). Analytical derivations are based on in situ stress conditions, Mohr–Coulomb and/or Hoek–Brown rock failure criteria and a non-associated elastoplastic strain softening material behaviour. The yield and caveability criteria are in agreement with results from both numerical studies and mine data.The caving number is normalised to mining conditions of a reference Chinese mine (LMX mine) and is used to assess LTCC performance at fourteen other Chinese working longwalls that have had varying success with the LTCC technology. The caving number is found to be in good agreement with observations from working LTCC mines. As a predictive model, results of this analytical/numerical study are useful to assess the potential success of caving in new LTCC operations and in different mining conditions.     

Comparative analysis of triacylglycerols from Olea europaea L. fruits using HPLC and MALDI‐TOFMS

MALDI‐TOFMS and HPLC are two analytical methods that were used to characterize triacylglycerols (TAG) of the Meski, Sayali, and Picholine Tunisian olive varieties. The HPLC chromatograms of the oils showed the presence of 15 TAG species, among which triolein (OOO) was the most abundant (21–48%). In the Sayali cultivar, OOO was the predominant TAG species followed by POO and LOO. However, the minor TAG molecules were represented by LnLO and LnLP. MALDI mass spectra produced sodiated ([M + Na]⁺) and potassiated ([M + K]⁺) TAG molecules; only the major TAG were potassiated [OOO + K] ([OOO + K]⁺, [POO + K]⁺, and [LOO + K]⁺). In contrast to the HPLC chromatograms, the MALDI mass spectra showed 13 peaks of TAG. The major peak was detected at m/z 907, which corresponds to OOO with an Na⁺ adduct. The results from both HPLC and MALDI techniques predict the fatty acid composition and their percentages for each olive variety. Practical applications: TAG are the main components in vegetable oils. These biomolecules determine the physical, chemical, and nutritional properties of the oils. The nutritional benefits of TAG are related to DAG (moderate plasma lipid level) and esterified FA, which are intermediate biosynthetic molecules of TAG. TAG analysis is necessary to discriminate between oils of different origin, since some oils have similar FA profiles. Olive products, oils, and table olives, are the main diet sources of TAG in the Mediterranean countries. In this work, chromatographic and spectrometric methods were used for TAG analysis and characterization of Tunisian olive varieties.     

Liquid chromatographic–mass spectrometric analysis of glycerophospholipids in corn oil

The phospholipid composition of corn oil was determined by LC/ESI-MS. The content of phospholipids in the oils varied from 5.2% to 8.7%. The major components in the phospholipids fraction were phosphatidylcholine (57.5–68.1%), phosphatidylinositol (14.5–19.8%), and phosphatidylethanolamine (10.3–13.9%). Phosphatidic acid and phosphatidylglycerol accounted for less than 10% of total phospholipid content. Various molecular species within each class were detected. The phosphatidylcholine class was mainly composed of phosphatidylcholine-C18:2/C18:1 (40–45%) and phosphatidylcholine-18:1/C18:1 (40–51%). Phosphatidylinositol-C16:0/C18:2 (50–69%) was the most abundant phosphatidylinositol. The two phosphatidylethanolamines were phosphatidylethanolamine-C16:0/C18:2 (34–42%) and phosphatidylethanolamine-C18:2/C18:2 (31–36%). Phosphatidylglycerol species were mainly phosphatidylglycerol-C16:0/C18:2 (42–48%) and phosphatidylglycerol-C16:0/C18:1 (36.7–40.3%). Identification of PC molecular species suggests the possibility that corn oil can have therapeutics effects.     

Fog collection as a source of fresh water supply in the Kingdom of Saudi Arabia

In order to harvest water contained in fog, the topographical features and the climatic conditions of 27 cities in the Kingdom of Saudi Arabia were studied. The topography, altitude and orientation are some of the factors that determined the selection of the site. It was identified that the southwest of the region in the kingdom was the most suitable location for the fog‐collection process. In order to evaluate the effectiveness of fog water collection and the site, three identical standard fog collectors (SFCs) with two different local collection materials were designed and manufactured. Experiments were conducted at two different locations in the area close to Abha, namely Soodha. The maximum amount of water collected was 22.9 L/m² in a day and 7.25 L/m² in a 2‐h period. It was found that there was a high probability of fog when the relative humidity was higher than 95%. The results from the chemical analyses of eight sets of fog water samples collected were compared with World Health Organization drinking water standards. It was found that the level of heavy metals was negligible and the level of Fe was marginally high for the first flush only. The study indicates that in terms of both quality and magnitude of yield, fog is a viable source of water and can be successfully used to supplement water supplies in the fog‐prone regions of the kingdom.