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Utilization of date palm tree fibres as biomass resources for developing sustainable composites for industrial applications
This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University London.Petroleum based fibres are dominating our everyday usage of fibres, textiles, and composite development reaching an annual consumption of more than 50 million tons in 2020. Over the years, there has been a desperate need for sustainable alternatives; but unfortunately, the global production of natural fibres (NF) has reached a plateau due to the reliance on very few natural sources and lack of biodiversity. With the growing concern on climate change due to the pollution emitted from petroleum-based manufacturing products and their end life disposal, sustainable manufacturing of sustainable materials represents a primary concern for the construction industry. New technologies and materials are extensively investigated and proposed to meet sustainability guidelines imposed by governments and specifically the United Nations (UN). NF represent one of the most investigated renewable and sustainable materials. The date palm tree (DPT), Phoenix Dactylifera L., produces globally an approximate of 4.8 million tons (dry weight) where 3.6 million tons are produced in the MENA region only as by-products of pruning, regarded as agricultural waste, which are either landfilled or incinerated. This research investigates and develops novel methodologies to overcome the drawbacks of utilizing DPT by-products where DPT fibre (DPF) can be extracted from and utilized as a reinforcement in developing sustainable composites for industrial applications. An intensive literature review database was developed to highlight previous research work and investigations carried out to date on the utilization of DPF and their effect in developing sustainable composites and the drawbacks limiting their feasibility for upscaling and industrialization. This identified the problem statement in current research that must be addressed to distinguish the potential of DPF utilization and industrialization.
Various surface modification treatments as well as their conditions (soaking time and duration) effect on the characteristics of DPF (surface morphology, chemical composition, chemical structure, and crystallinity) was investigated and evaluated to develop a more hydrophobic fibre that enhances the interfacial bonding when used as a reinforcement with various matrix systems (i.e., polymers and cementitious). DPF treated with sodium hydroxide (NaOH) solution, 6%, for 3 hours showed optimal results where an increase in tensile strength of the fibre by 147%. Scanning electron microscopy (SEM) images demonstrated the effectiveness of the surface treatment showing a more porous surface where the impurities and waxes were successfully removed. Furthermore, investigations, evaluation and prediction on the effect of DPF particle size distribution, density, diameter size (unsieved, ≥1,000 μm, 500 – 1,000 μm, 250 – 500 μm, 125 – 250 μm, and ≤125 μm) and loading content (10, 20, 30, 40 wt.% of matrix) on both the mechanical, physical, fungal resistance and disintegration properties of recycled thermoplastic, recycled polyvinyl chloride (RPVC), and biodegradable thermoplastic, polylactic acid (PLA), were evaluated. The hydrophilic nature of DPF contributed to an increase in thickness swelling (TS), moisture content (MC) and water absorption (WA) for both RPVC and PLA reinforced composites. TS, WA and MC increased by 1.57%, 1.76%, and 10.80%, respectively at 40 wt.% DPF loading content when reinforced with RPVC. Moreover, the flexural strength, tensile strength and impact strength decreased as the loading content increased showing maximum reduction at 40 wt.% loading, varying depending on DPF geometry. Furthermore, micromechanics modelling scenarios to predict the fibre orientation was investigated. To determine the effectiveness of DPF orientations in the PLA and RPVC, the rule of mixtures (ROM), modified ROM, inverse rule of mixture (IROM), modified IROM and Halpin-Tsai were applied with three possible fibre orientations in the composites. The modified ROM and modified IROM closely matches the experimental results with the DPF oriented between 0° to 45° in the direction of compression force of the DPF/PLA and DPF/RPVC composites. Also, Composites where exposed to the brown-rot fungus Irpex lacteus and white rot fungus Tyromyces palustris to evaluate its resistance to biodegradation. To evaluate their feasibility to be utilized in the construction sector as a cladding and decking composite which can act as a substitute to wood in developing wood plastic composites (WPC). Composites developed using PLA had higher weight loss (%) when compared to the same samples but reinforced with RPVC. Composites with higher DPF content showed high rates of decay when used with different polymer matrix. Also, DPF length had a significant effect on the disintegration of the composites. DPF/PLA composites did not demonstrate significant weight loss under fungal decay in 8 weeks where the composites with 40 wt.% DPF showed the highest WL% reaching 5.61% and 5.46% when exposed to Tyromyces palustris and Irpex lacteus respectively. Furthermore, a novel investigation on the biodegradation of the samples showed that DPF reinforced PLA can be implemented and developed within a circular economy scheme in which the composite was fully decomposed by earth worm within 6 weeks, developing vermicompost as manure that may be utilized as a nutrient for plants.
Furthermore, an investigation of the processing parameters effect (processing time, temperature, and pressure) on the physical and mechanical properties of DPF reinforced polyester (PES) composite is evaluated. For that, two different temperatures (90 and 110 oC) and three different pressures (1.0, 1.65, and 2.18) MPa which was achieved by varying the load applied (10, 15, and 20) ton and keeping the sample size constant are examined for three different processing durations (3, 6, and 9 min). Results showed that every processing parameter had different effects on the mechanical and physical properties of the composites developed. Moreover, investigations on the effect of varying DPF loading content (1, 2, and 3 wt.% of matrix), and length (10, 20, 30, and 40 mm) of untreated and alkali treated DPF on the mechanical properties of DPF reinforced Ordinary Portland cement (OPC) and DPF reinforced OPC/ground-granulated blast furnace slag (GGBS) were evaluated. Two different curing conditions, water and air, effect on the mechanical strength and physical properties of the composites developed were explored. Results showed that the inclusion of 20 mm treated DPF at a loading content of 1 wt.% with OPC/GGBS as a matrix showed the greatest enhancement in strength by 57.12% and 30.97% of flexural and compressive strength respectively at 28 days of ageing in a water bath. Alkali treatment of DPF demonstrated higher mechanical properties enhancing the optimal mix designs’ mechanical strength by 10% and at 28 days of water curing when compared to the untreated. Moreover, OPC as a pure matrix system had lower mechanical properties where the optimal mix design had an increase in 37.48% and 19.36% on flexural and compressive strength respectively at 28 days of curing in a water bath when compared to OPC/GGBS reinforced composites.
Overall, this thesis paves the way for developing a comprehensive foundation for utilizing DPT by-products by optimizing the parameters of surface modification, fibre geometry, fibre loading, and processing parameters for developing sustainable composites that can be industrialised for various non-structural industrial applications (i.e., construction and automotive industries)
STRUCTURAL AND MAGNETO CONDUCTIVITY STUDIES OF NIO/SMBA2CU3O7-Δ SUPERCONDUCTING COMPOSITE
In this work, we investigate the effect of NiO nanoparticles\u27 addition on the structure, superconductivity, and magneto conductivity for the SmBa2Cu3O7-δ phase. Composite nano/superconductor of (NiO)x/SmBa2Cu3O7-δ (0.00≤x≤0.12 wt.%) were prepared by conventional solid-state reaction technique and characterized by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The orthorhombic structure was maintained whereas the lattice parameters showed unsystematic variations with the NiO nanoparticles addition. The superconducting transition temperature Tc, determined from electrical resistivity measurements, showed an enhancement with x up to 0.04wt.% followed by a reduction with higher NiO additions. The Aslamazov–Larkin (AL) model was employed to analyze the magneto conductivity. The model allowed to determine the coherence lengths along c-axis ξc(0) and along ab plane ξab(0). Moreover, the anisotropy parameter Г increase with the increase of NiO nanoparticles addition
Toxicology in Emergency Medicine
Poisoning is a serious worldwide public health problem. Based on WHO data in 2012, almost 190,000 people died worldwide and the number of deaths due to poisoning in 2008 exceeded the number of deaths due to motor vehicular crashes; also, poisoning death rate nearly tripled worldwide. Number of patients presenting to the emergency departments with overdose, had been increased both intentionally and accidentally. All the previous facts make Toxicology an important field in emergency medicine. Management of intoxicated patients has a unique approach because of the challenge in diagnosis and treatment of overdose cases. This chapter is focusing on general approaches for intoxicated patients and initial management and on how the history and physical examinations could help physicians to have what drug have been abused as well as review the mechanism of action, physical finding and treatment of the most common drugs-causing toxicity in addition to the drugs with high mortality morbidity rates
The impact of electronic documents management on performance
The aim of this research was to study the impact of electronic documents management on performance. To accomplish this objective, the researcher prepared a questionnaire composed of two parts. The first part concerned with collecting demographic data, while the second part was concerned with collecting data and information regarding the impact of electronic documents management on performance. The collected data were entered to the computer through the Statistical Package for Social Sciences (SPSS). The results showed positive attitude of the sample unit regarding electronic management of documents and performance. The results showed no correlation between electronic document management and performance, so the study recommended the enhancement of employees to learn more about electronic document management at their work. Key words: Documents Management, and Performance
The impact of electronic documents management on performance
The aim of this research was to study the impact of electronic documents management on performance. To accomplish this objective, the researcher prepared a questionnaire composed of two parts. The first part concerned with collecting demographic data, while the second part was concerned with collecting data and information regarding the impact of electronic documents management on performance. The collected data were entered to the computer through the Statistical Package for Social Sciences (SPSS). The results showed positive attitude of the sample unit regarding electronic management of documents and performance. The results showed no correlation between electronic document management and performance, so the study recommended the enhancement of employees to learn more about electronic document management at their work. Key words: Documents Management, and Performance
New Techniques for Disconnector Switching VFT Mitigation in GIS
Switching operations in a Gas Insulated Substations (GIS) generate very fast transient over voltages (VFTO) which are dangerous for the transformer and the system insulation because of their short rise time. Under special circumstances the overvoltages can arise close to the transformer Basic Insulation Level (BIL). The reduction of VFTO amplitudes is considered main challenges. Therefore, VFTO in the 220 kV Wadi-Hoff GIS is analyzed and the worst case for disconnector switching is predicted using EMTP/ATP in this paper. VFTO mitigation techniques are studied in this work. Furthermore, proposed techniques are presented for mitigating the VFTO. The proposed techniques can be used by the maintenance engineers, transformer designers, and GIS insulation manufactures. The results show that the proposed techniques highly reduce the VFTO in a simple manner.DOI:http://dx.doi.org/10.11591/ijece.v4i2.518
Angular Regioselective Synthesis of Varied Functionalized Hexahydro-1,2,4-triazolo[4,3-a]quinazolin-9-ones and Their Antiproliferative Action
New 2-thioxopyrimidin-4-ones capable of participating in regioselective reactions with functionally diverse hydrazonoyl chlorides towards angular regioisomers, rather than linear ones, were designed and synthesized to form stereoisomeric cis- and trans-hexahydro [1,2,4]triazolo[4,3-a]quinazolin-9-ones to be tested as antitumor candidates. The angular regiochemistry of the products was verified through crystallographic experiments and NMR studies. In addition, the regioselectivity of the reaction was found to be independent of the stereochemistry of the used 2-thioxopyrimidin-4-one. Only compound 4c demonstrated satisfactory growth inhibition against all the cancer cells used among all the produced drugs
Detection of FXIII gene V34L and fibrinogen β-gene -455G/A polymorphisms among Saudi Arabia population via polymerase chain reaction-reverse hybridization technique
FXIII gene Val34Leu variant appears to be associated with decreased risk of myocardial infarction and venous thromboembolism as well as with increased risk of intracerebral hemorrhage. Fibrinogen β-gene SNP -455G/A are associated with differences in the plasma levels of fibrinogen and severity of arterial disease. The aim of the present work was to study the prevalence of FXIII gene V34L and Fibrinogen β-gene -455G/A SNPs in Saudi population. Among 200 blood samples randomly collected from unrelated healthy Saudi subjects, FXIII gene V34L and Fibrinogen β-gene -455G/A SNPs were genotyped via cardiovascular disease (CVD) StripAssay (ViennaLab, Austria. Homozygous (V/V) and heterozygous (V/L) genotypes were detected with 96 and 4%, respectively, among FXIII gene V34L genotypes, whereas (L/L) genotype was not found. The allele frequency was 0.98 for V allele and 0.02 for L allele. Three genotypes of Fibrinogen β-gene -455G/A SNP (GG, GA and AA) were obtained and its prevalence (%) was 70, 25 and 5, respectively. The frequency of G allele was 0.825 and 0.175 for A allele. Prevalence of FXIII gene Vl34L polymorphism and its allele frequency are in line with other Asian populations. Distribution of β-gene -455G/A genotypes and allele frequency are in accordance with previous reports in different ethnic groups. This is the first time to report these polymorphisms in Saudi Arabia population. This study provides valuable information on Saudi genetic background in comparison with other populations. In addition, it serves as a template for future clinical research involving cardiovascular and cerebrovascular diseases.Key words: FXIII gene V34L, fibrinogen β-gene -455G/A, polymorphisms, Saudi Arabia
The protective effects of cerium oxide nanoparticles against hepatic oxidative damage induced by monocrotaline
Kamal A Amin1, Mohamed S Hassan2, El-Said T Awad3, Khalid S Hashem11Department of Biochemistry, 2Department of Internal Medicine, Faculty of Veterinary Medicine, Beni-Suef University, Beni-Suef, Egypt; 3Department of Biochemistry, Faculty of Veterinary Medicine, Cairo University, Cairo, EgyptObjective: The objective of the present study was to determine the ability of cerium oxide (CeO2) nanoparticles to protect against monocrotaline (MCT)-induced hepatotoxicity in a rat model.Method: Twenty male Sprague Dawley rats were arbitrarily assigned to four groups: control (received saline), CeO2 (given 0.0001 nmol/kg intraperitoneally [IP]), MCT (given 10 mg/kg body weight IP as a single dose), and MCT + CeO2 (received CeO2 both before and after MCT). Electron microscopic imaging of the rat livers was carried out, and hepatic total glutathione (GSH), glutathione reductase (GR), glutathione peroxidase (GPX), glutathione S-transferase (GST), superoxide dismutase (SOD), and catalase (CAT) enzymatic activities were quantified.Results: Results showed a significant MCT-induced decrease in total hepatic GSH, GPX, GR, and GST normalized to control values with concurrent CeO2 administration. In addition, MCT produced significant increases in hepatic CAT and SOD activities, which also ameliorated with CeO2.Conclusions: These results indicate that CeO2 acts as a putative novel and effective hepatoprotective agent against MCT-induced hepatotoxicity.Keywords: monocrotaline, ceruim oxide nanoparticle, hepatotoxicity, oxidative stres
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