United Arab Emirates University
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CORROSION BEHAVIOR OF 304 STAINLESS STEEL IN H2SO4/NACL IN THE ABSENCE AND PRESENCE OF MOLYBDATE AND TUNGSTATE
Get PDFIn this study, the corrosion behavior of 304 austenitic stainless steel was investigated in H2SO4 solutions, H2SO4 as a function of Cl- ions concentration, H2SO4 as a function of MoO42- ions concentration, and H2SO4 + Cl- ions as a function of MoO42- ions concentration. Moreover, the synergistic inhibition of MoO42- and WO42- ions was investigated in 0.1 M H2SO4, with the solution pH adjusted to 3.0. The findings show that the corrosion current density (icorr) increases while the polarization resistance (Rp) decreases with increased H2SO4 concentrations in the absence of Cl- ions. In the presence of Cl- ions, icorr increases whereas Rp decreases with increasing Cl- concentration in ≤1M H2SO4 solutions. In contrast, in concentrations ≥ 2M H2SO4, icorr decreases while Rp increases with increasing Cl- ions concentration up to ~ 0.5-1.0 M Cl- ions concentration, while the trend is reversed in concentrations ≥ 1M NaCl as the Rp decreases and icorr increases with increasing Cl- ions concentration. The pitting potential (Epit) decreases as Cl- ions concentration increases in a given H2SO4 concentration as expected; however, no correlation is found between Epit and [Cl-]/[H2SO4] ratio or Epit and [Cl-] when solutions of different concentrations of H2SO4 + Cl- were taken into consideration.The MoO42- ions acted as an excellent corrosion inhibitor in H2SO4 solutions in the absence of Cl- ions, with the IE% exceeding 99%. However, in H2SO4 solutions in the presence of Cl- ions, MoO42- ions acted both as a corrosion accelerator and a corrosion inhibitor depending on the concentrations of H2SO4, Cl- ions, and MoO42- ions, with the inhibition tendency increasing with the decrease in the Cl- concentration and the increase in the MoO42- concentration. For the MoO42- ion to effectively induce inhibition in H2SO4 + NaCl solutions, its concentration must be high enough to shift the corrosion potential to the passive range in the polarization curves. Finally, both MoO42- and WO42- ions acted as excellent corrosion inhibitors of 304 stainless steel in 0.10 M H2SO4 (pH = 3.0), with the two ions showing a synergistic inhibition effect, with the maximum corrosion inhibition occurring when a 1:1 concentration ratio was used
DEVELOPMENT OF NOVEL NANOBIOCATALYSTS FOR ENHANCING CARBON DIOXIDE CAPTURE
Get PDFThe emissions of greenhouse gases to the atmosphere cause a climate change that has devastating impacts. Therefore, reaching the net zero goal, which is the balance between the amount of greenhouse gas emitted to the atmosphere and that removed from it, is critical for the future of our planet unless the net-zero goal is achieved soon, the impacts of climate change will continue to worsen, with severe consequences for ecosystems, human health, and global security. Achieving this goal requires a fundamental shift in the way we produce and consume energy, including the rapid transition to renewable energy sources with improvements in energy efficiency. However, full transformation into renewable energy is a challenging task that requires significant time, effort, and resources. Until this full transformation is reached, if ever, carbon capture will continue to play a key role in achieving the net-zero goal. Post-combustion capture of CO2 is the most suitable technology to enable the reduction of emissions from hard-to-abate sectors, such as heavy industries and transportation. However, the conventional CO2 capture technologies, which mainly depend on the amine-based chemical absorption, face several challenges that need to be overcome. These challenges are mainly the high energy needed for solvent regeneration, rendering the process energy intensive and expensive, solvent corrosivity, requiring frequent maintenance, and leading to higher operating costs, and solvent decomposition, resulting in a loss in efficiency. To overcome these challenges, novel nano-biocatalysts have been tested in this work for the development of nano-fluids that can replace the conventional amine solvents for CO2 capture. The aim was to develop environmentally friendly and cost-effective nano-biocatalysts that allow combining the enhancement of CO2 uptake of nanofluids with the catalytic effect of the Carbonic Anhydrase (CA) enzyme. The synergetic effect of the combination of biotechnology and nanotechnology is expected to enhance the overall performance, compared to that of each technology alone. Enzyme immobilization allows easy repeated reuse, which is not possible using the enzyme in free form. Using nano-particles as immobilization support reduces the mass transfer limitations, commonly encountered with conventional porous supports. Selecting nanoparticles that have adsorption capacity further increases the effectiveness of the process. In this study, four nano-biocatalysts were synthesized by immobilizing bovine carbonic anhydrase onto metal-organic framework (ZIF-8), Iron oxide (Fe2O3), Graphene, and Graphene Oxide (GO) nanoparticles. The nanoparticle and the developed nano-biocatalysts, before and after the reaction, were characterized for their morphology, infrared spectrum, pore size surface area, and hydrophobicity. The results proved the successful adsorption of the enzyme and the stability of the developed nano-biocatalysts. The performance of the developed nano-biocatalysts on CO2 flux has been investigated at different temperatures, dosing, and CO2 pressures.GO nanoparticles showed the best result of CO2 flux with a 92.7 % enhancement of flux compared to that of pure water. By CA immobilization, the CO2 flux enhanced further over that of the free nanoparticles by 32, 21, 37, and 42 % for CA@ZIF-8, CA@Fe2O3, CA@graphene, and CA@GO, respectively. Besides showing the best performance, CA@graphene and CA@GO showed very high reusability, with their activity remained almost unchanged for up to 5 cycles. To further understand the behavior, diffusion-reaction kinetics of CA@GO, the nano-biocatalyst with the best performance, has been analyzed. The present results prove that the developed nano-biocatalysts possess great potential for industrial-scale environmentally friendly and cost-effective CO2 sequestration. The work presented here represents a significant advancement in the field of biotechnology and nanotechnology by demonstrating the synergetic effect of combining these two fields through the use of nano-biocatalysts. This is the first time that such nano-biocatalysts have been tested in the manner presented in this work, making it a novel contribution to the scientific community. In addition, the development of a mathematical kinetics model that considers simultaneous diffusion and reaction provides a more comprehensive understanding of the process. Overall, this work offers a unique and innovative approach to addressing complex biotechnological challenges and opens up exciting avenues for further research in this area
PRICING ASIAN OPTIONS DURING CRISES WITH THE IMPACT OF EXOGENOUS EVENT
Get PDFAsian options are financial derivatives products whose value depends on the value of underlying asset prices. These options are called path-dependent since their payoff is built on the prices of the underlying asset over some time. As in the case of the European options, the Asian option pricing problem is primarily subject to the prediction model for asset prices. The pioneer Black-Scholes model in the paper [2] suggests a GBM-Geometric Brownian motion. The Black-Scholes formula has several shortcomings. For instance, the Geometric Brownian motion does not take into consideration crises. Another problem in the Black- Scholes model is that it does not deal with the impact of external event. The study discusses these two shortcomings. This work aims at suggesting a model that encompasses the impacts of crises and external events together. It will be based mainly on the papers of [5] and [8] for models with crises and the work of [4] and [12] to model the effect of an external event. The underlying asset is then driven by a stochastic differential equation with a modulated Markov GBM and an increase in volatility. Determining the price of an Asian option will be explored under the suggested model. Moreover, numerical techniques will be employed to get a numerical solution and to simulate trajectories for the prices of the options and the underlying asset
TRANSFORMER-BASED DEEP LEARNING MODEL FOR SIGN LANGUAGE RECOGNITION
Get PDFSign language recognition research aims to develop systems and tools that can interpret and translate sign language into text or spoken language. During the past two decades, the challenges faced in this domain are multifaceted. The first and foremost challenge is the complexity of sign language, which includes intricate hand gestures, facial expressions, and body movements. Recognizing and interpreting these components accurately is challenging. The second challenge is variability among different regions and communities, leading to variations in signs and gestures. This variability poses a challenge for developing universal recognition systems.Limited data is another challenge which makes it difficult to train accurate recognition models. This scarcity of data hinders the performance and generalization of machine learning algorithms. Sign language communication often occurs in real-time, requiring recognition systems to process gestures quickly and accurately. Achieving real-time performance adds complexity to the design of recognition systems.Some signs may have multiple meanings depending on context or subtle differences in execution. Disambiguating these signs accurately is crucial for reliable recognition. Furthermore, sign languages incorporate non-manual components such as facial expressions and body posture, which convey important linguistic information. Integrating these components into recognition systems poses additional challenges.Sign language recognition systems may perform differently for different users based on factors such as signing speed, style, and proficiency. Developing systems that can adapt to individual users\u27 signing characteristics is challenging. Additionally, deploying sign language recognition systems on hardware platforms with limited computational resources, such as mobile devices, presents challenges in achieving high performance while maintaining low latency.This thesis on sign language recognition aims to address some challenges through various approaches. The foremost challenge addressed in this thesis is reduction in accuracy that uses transformer-based deep learning architecture in addition to preprocessing steps that include augmentations and transformations. The augmentations and transformation helped increase the data size. Specifically, in-house signs have been generated using different persons for initial results. The video frames generated included facial expressions and both fingers, which were later stacked. Later, the model was validated using generic sign languages to address. For producing results, the model was trained and assessed on a set of frames. The comparisons with existing works are tabulated. Based on comparative results, it was found out that the accuracy of the proposed model assessed on WLASL2000, and ASL-Citizen datasets is higher than the state-of-the art models
ENHANCEMENT OF RAINFALL PREDICTION AND SATELLITE PRECIPITATION ESTIMATES: A MACHINE LEARNING APPROACH FOR UNITED ARAB EMIRATES
Get PDFThe accurate estimation of rainfall in arid regions presents a significant challenge due to sparse ground observations and complex atmospheric dynamics. This dissertation investigates various aspects of rainfall estimation and prediction in the United Arab Emirates (UAE), employing Satellite Precipitation Products (SPPs) and Machine Learning (ML) techniques. The research is structured around four key articles, each addressing different facets of the overarching theme. The first publication examines rainfall variability, consistency, and concentration in the UAE by comparing satellite precipitation products with rain gauge observations, highlighting the discrepancies between the two data sources. The second publication evaluates the performance of precipitation estimates from the PERSIANN family of remote sensing products in an arid region, providing insights into their reliability and limitations. The third article focuses on the accuracy of machine learning models in improving monthly rainfall prediction in hyper-arid environments, offering valuable contributions to the field of hydrological forecasting. Finally, the fourth article discusses the development of a bias correction framework using machine learning algorithms to remove systematic biases from satellite precipitation products over arid regions, enhancing their utility for hydrological applications. By synthesizing findings from these publications, this dissertation contributes to the advancement of rainfall estimation and prediction techniques in arid regions, offering valuable insights for water resource management and climate studies in the UAE and beyond.The SPPs were validated over varying geographical areas and multiple statistical and categorical predictors were utilized for their performance evaluation including Correlation Coefficient (CC), Root Mean Squared Error (RMSE), Probability of Detection (POD), Heidke Skill Score (HSS), and False Alarm Ratio (FAR). Additionally, the study introduced various extreme indices including Rx1day (mm), R10mm (days), R20mm (days), R30mm (days), consecutive wet days (CWD), and consecutive dry days (CDD) to accurately assess the accuracy of the products based on extreme events. Precipitation Concentration Index (PCI) and Shannon Diversity Index (SDI) were also utilized to assess the uneven spatial and temporal precipitation distribution. Various individual and ensembled ML algorithms were tested for the rainfall prediction in the study area to develop a belief in the appropriateness of the models and to successively use for the bias correction step. The selected SPPs were corrected by using the topographic and wind speed factors while utilizing the Long Short-Term Memory (LSTM) machine learning architecture. The outcomes of this research are multifold and can assist and define the future research lineage specifically for the study site i.e., UAE. The bias correction of the SPPs resulting in improved accuracy and decreased uncertainty may potentially lead toward using the precipitation data from the SPPs for various hydrological and climatological models. Therefore, the areas with lack of gauge installation can be studied and included in the analysis as well
الجريمةُ الأصليَّةُ كشرطٍ مُفترضٍ لجريمةِ غسلِ الأموالِ طبقًا للمرسوم بقانونٍ اتحاديٍ رقْم 20 لسنة 2018 في شأن مُواجهة جرائمِ غَسْلِ الأموالِ ومكافحة تمويل الإرهاب وتمويل التنظيمات غير المشروعة المعدل بالقانون رقم (26) لسنة 2021م
Get PDFThe Predicate Crime as a Presumptive Condition for the Crime of Money Laundering in Accordance with Federal Decree Law No. 20 Of 2018 Regarding Combating Money Laundering Crimes and Combating the Financing of Terrorism and the Financing of Illegal Organizations, As Amended by Law No. 26 of 2021
The crime of money laundering is closely linked to the crime from which the funds being laundered are obtained. There is no talk of money laundering without funds derived from an illicit source. Hence the question arises about the nature of the original crime, and whether it includes every crime from which illicit funds arise, or whether the matter is limited to specific crimes, as the crime of money laundering is an accessory crime in nature and its legal structure is not complete unless the original crime occurs. The federal legislator, in accordance with the second paragraph of Article 2 of Federal Decree Law No. (26) of 2021 amending some articles of Federal Decree Law No. 20 of 2018 regarding combating money laundering crimes and combating the financing of terrorism and the financing of illegal organizations, stated that “the crime of money laundering is considered a crime! Independently, and punishing the perpetrator of the original crime does not prevent him from being punished for the crime of money laundering.”
In this study, attention was paid to determining the extent of the independence of the crime of money laundering from the original crime as an assumed condition, as well as the sources on which proof of the crime depends, the imposition of the penalty for the original crime, and the imposition of the penalty for the crime of money laundering, in deviance from the rule of applying the most severe punishment in the case of an unacceptable connection. Through this, we wanted to clarify the validity of the rulings issued in acquittal and conviction in the original crime over the ruling in the crime of money laundering
GOVERNANCE OF RELIGIOUS AFFAIRS IN THE UNITED ARAB EMIRATES
Get PDFThis study seeks to investigate policies, measures and efforts on religious affairs governance in the UAE, through enacting laws and establishing local religious institutions by uncovering the necessity of the procedures that are in place, the goals of religious governance, how religious affairs are regulated, and the challenges that the government faces in the process. The main objective of this thesis is to provide one possible adoption model for religious regulation. Further, since there are few studies on the topic of religious governance in general, and in the UAE particularly, the researchers synthesized and integrated existing knowledge from diverse sources to provide a comprehensive overview of the topic and highlighted the patterns and trends
A Review of Geopolymer Cement, from Two-Part Geopolymer to One-Part Geopolymer cement and its Geotechnical Applications
Get PDFAbstract
Portland cement, a crucial construction material, has been used extensively in various geotechnical projects. However, its over-reliance has led to environmental concerns, particularly regarding carbon dioxide (CO2) emissions during its production. Sustainable development involves the development of cement alternatives that are less damaging to the environment. Geopolymer cement can be a potential partial replacement for conventional Portland cement that can minimize carbon dioxide emissions and convert various by-products into useful products. Traditional geopolymer cement is composed of two components: an alkaline activator solution and a solid aluminosilicate precursor (other than water), and its production requires the manipulation of large volumes of viscous, hazardous, and corrosive alkaline activator solutions. As a result, there is pressure to develop one-part or water-only geopolymer cement. This review presents current research on geopolymer cement, including its composition, strength, possible applications, and the development of one-part geopolymer cement and its geotechnical applications.
Keywords: alkali-activated material, one-part geopolymer cement, Portland cement, geotechnics, soil treatment, soil stabilizatio
Evaluation of opportunities for the cultivation of heterotrophic plant root organ cultures as food: Optimization of culture conditions and carbohydrate sources
Get PDFAll agricultural plant production requires investment of water, energy, and land, especially in the Gulf Region, where environmental conditions are not ideally suitable for crop farming. Currently, less than 40 % of agricultural produce constitutes food, which greatly limits the overall feasibility of food production systems worldwide. Crop residues contribute more than half to global agricultural plant production, and food waste and biomass from public parks and gardens further add to the vast pool of non-edible plant material. Existing valorization strategies for such material cannot compensate for the enormous amounts of water, energy, land, and human resources invested in their production. A comparatively small portion of non-edible plant biomass is suitable as feed for farm animals and can be converted into animal products at ratios of typically 7 – 10 %. Given the poor conversion efficiency and high greenhouse gas emissions of animal production systems, innovative solutions for conversion of non-edible into edible biomass are urgently required. The present study tested the concept of conversion of non-edible crop residues into edible plant material via heterotrophic plant organ cultures rather than farm animals. Following acid, enzymatic, or microbial hydrolysis, cellulosic waste could be converted into a mixture of monosaccharides, dominated by glucose. The present study characterized the ability of in vitro crop root organ cultures to utilize externally provided sugars for growth, thus converting soluble carbohydrates into edible plant biomass. Results revealed that plant species differ in their heterotrophic capabilities. When grown on sucrose, basil roots were able to convert up to 70% of the supplied carbon into their biomass. Conversion rates on media based on glucose were slightly less efficient compared with those based on sucrose, but still achieved conversion rates of up to 50 %. The efficiency by which cellulosic plant material can be converted into sugars typically lies in the range of 50 – 70 %. Based on this and the results of the present study, root organ cultures would achieve an overall conversion efficiency of 25 – 30 %, far outperforming farm animals and other existing bioreactor-based conversion systems, e.g., based on cell cultures, bacteria, or algae. The present study identified likely opportunities for further improvement of this conversion system. As revealed by the mineral element analysis of the root organ cultures, the Ca and P supply of these plant tissues likely limited their growth performance. Future studies should elucidate reasons for this and develop strategies for increasing the availability of these elements to in vitro root cultures. A comparison of different gelling agents and physical properties of the growth medium revealed only small differences, suggesting that the gelling agent type and strength are not major determinants of culture performance. Liquid cultures did not differ from those on solid media in their ability to utilize sucrose for growth. Further improvement of the conversion efficiency can likely be achieved by culture aeration, e.g. through forced ventilation. Based on the present findings, T-DNA transformation of root organs is not a prerequisite to achieving high biomass conversion rates. In non-transformed, adventitious roots supplied with IBA, the conversion efficiency likely increases with an increasing number of explants added to the culture medium
الحماية الجنائية للمستهلك من الغش التجاري والاعلانات المضللة في ضوء التشريع الاماراتي
Get PDFCriminal Protection for The Consumer from Commercial Fraud and Misleading Advertisements in Light of UAE Legislation
In this study, we addressed the topic of criminal protection of the consumer from commercial fraud and misleading advertisements in light of the UAE legislation. We concluded that criminal protection of the consumer from commercial fraud and misleading advertisements is considered one of the important matters that aim to protect the rights of consumers and ensure their safety and security while dealing with various products and services. Criminal protection is one of the basics of consumer protection, as it aims to provide legal penalties for individuals or criminal entities that cause intentional harm to consumers.
Both the Anti-Commercial Fraud Law 42 of 2023 and the Consumer Protection Law 20 of 2021 included multiple penalties for the crime of commercial fraud and misleading advertisements, including imprisonment and a fine or either, confiscation, destruction of seized items and tools used, closing the facility, and publishing the conviction. The most severe of these shall be applied in either law. We have shown that the legislator has set a penalty ranging from imprisonment to a fine of up to five hundred thousand dirhams, or either, for anyone who makes misleading advertisements through electronic means in the Anti-Rumors Law No. 34 of 2021. We have recommended the enactment of an economic penal law specific to crimes of commercial fraud and misleading advertisements in the country, which includes the types of these crimes and specifies special provisions and applications for them