Hydrogen (H2) enrichment is a viable solution to deter the early blowout of oxy-fuel flames at high CO2 dilution levels and to enhance combustor turndown in the supercritical-CO2 cycles of ...zero-emission power plants. This was already implemented successfully in a previous study by the author, where H2 was premixed with the oxy-reactants upstream of the burner headend in a fully premixed flame stabilized on a micromixer-like burner. The micromixer technology is known for its superior flame stability and inherent fuel/oxidizer flexibility. To avoid the higher risk of flashback when H2 is premixed with the primary reactants, the present study introduces the enrichment H2 in a nonpremixed manner from the enhanced-blowout fuel circuit of the micromixer burner, which comprises circumferential jets that surround the core oxy-flame. This approach aims to enhance combustor turndown even further by benefiting from inducing stratification in the flame. It was found that the blowout limit of the fully premixed (CH4/H2/O2/CO2) flame did not improve by stratification (H2–CH4/O2/CO2); it deteriorated slightly. The present study thus analyzes the stability, morphology, and CO emissions of the stratified flame, in order to explain this behavior and provide recommendations for how hydrogen enrichment should be introduced in oxy-fuel micromixer combustors.
•Sugar cane bagasse and orange peel can be recycled into biochar for wastewater treatments.•The rapid and high sorption capacities make them very promising alternative sorbent materials.•Sugar cane ...biochar (SC-BC) was more effective in removing Pb(II) than orange peel (OP-BC).•The morphological features determine the removal efficiency of biochar for Pb (II).
In this study sugar cane biochar (SC-BC) and orange peel biochar (OP-BC) were used to remove Pb(II) ions from aqueous solutions. To achieve this goal, biochars were produced by the pyrolysis of biomasses at temperature less than 500°C by using a small-scale biochar producing plant. Furthermore, batch adsorption studies have been performed, and the effects of several factors, i.e., pH, contact time, initial Pb(II) ions concentration and temperature were investigated on Pb(II) ions sorption mechanism and optimizing the removal efficiency of Pb. Boehm titration method and Fourier transform infrared (FTIR) spectroscopy were employed to quantitatively describe the major function groups on the surface of biochars. The obtained results revealed the presence of carboxyl, hydroxyl, and carbonyl groups, which are likely responsible for the adsorption of Pb(II) ions. Given the same chemical structure, SC-BC was more effective in removing Pb(II) ions than OP-BC, with the removal capacities of 86.96mg/g, much higher than those of OP-BC (27.86mg/g). The equilibrium data were well fitted with Langmuir model and the adsorption process was well fitted by pseudo-second-order model. We suggested the major adsorption mechanisms of Pb(II) ions through a specific ion-exchange mechanism, and surface precipitation. Results indicated that not only the chemical composition but also the morphological structure plays an important role in the sorption nature of biochar.
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Purpose
This paper aims to present the components' characterization and condition assessment of an important deteriorated Mamluk-illuminated paper manuscript housed in Al-Azhar Library, Egypt.
...Design/methodology/approach
Different analytical techniques used in this study were the portable digital optical microscope, stereomicroscope, scanning electron microscope with EDX (SEM.EDX), portable X-ray fluorescence (pXRF), X-ray diffraction (XRD), pH measurement and Fourier transform infrared spectroscopy (FTIR).
Findings
The results obtained by different microscopes showed that the gilding in the surface of illuminated paper sheets was performed with gold leaves. Additionally, these microscopes revealed that the illuminated paper manuscript has different aspects of deterioration such as adhered dirt, staining, some micro-cracks, cracks and detachment of some parts in some illuminated areas. The results of elemental analysis by EDX, portable XRF and XRD analysis showed that the orange red pigment is red lead (Pb3O4), blue pigment is azurite (2CuCo3.Cu (OH)2), and the gold layer is has consisted of brass alloy (Cu-Zn) with a small amount of gold element (Au). The pH measurement stated that the historical paper in the acidity level. The ATR-FTIR analysis also revealed the oxidation of cellulose. Moreover, it was found from ATR-FTIR that Arabic gum was used as a binder for the pigments.
Originality/value
This study presents the important results of analytical methods used for condition assessment and identification of the components of an important Mamluk-illuminated paper manuscript, where these results referred that the studied paper manuscript had different aspects of deterioration. The conservation steps either conservation treatment or preventive conservation are urgently needed in future studies.
•Sugar cane bagasse and orange peel can be recycled into biochar for soil application.•Application of SC–BC and OP–BC improved the physicochemical properties of the studied soil.•Both biochars can ...reduce the leachability of Pb in a metal smelter-contaminated soil.•Addition of SC–BC and OP–BC resulted in greater mobility of As in the treated soil.•Considerable attention should be paid when using the biochar in soil contaminated with As.
The main objectives of the current study were to evaluate the potential effects of biochar derived from sugar cane bagasse (SC–BC) and orange peel (OP–BC) on improving the physicochemical properties of a metal smelter contaminated soil, and determining its potentiality for stabilizing Pb and As in soil. To achieve these goals, biochar was produced in a small-scale biochar producing plant, and an incubation experiment was conducted using a silt loam metal-contaminated soil treated with different application rates of biochar (0–10% w/w). The obtained results showed that, the addition of SC–BC and OP–BC increased significantly the soil aggregate stability, water-holding capacity, cation exchange capacity, organic matter and N-status in soil. SC–BC considerably decreased the solubility of Pb to values lower than the toxic regulatory level of the toxicity characteristics leaching procedure extraction (5mgL−1). The rise in soil pH caused by biochar application, and the increase of soil organic matter transformed the labile Pb into less available fractions i.e. “Fe–Mn oxides” and “organic” bound fractions. On the other hand, As was desorbed from Fe–Mn oxides, which resulted in greater mobility of As in the treated soil. We concluded that SC–BC and OP–BC could be used successfully for remediating soils highly contaminated with Pb. However, considerable attention should be paid when using it in soil contaminated with As.
The tremendous increase in energy demand due to increased population and rapid economics results in an increased level of atmospheric pollutants and global warming. The global shift to the use of ...renewable clean energies still has some restrictions in terms of the availability of the advanced reliable technologies and the cost of application compared to conventional fossil fuels. Until we can have this full conversion to renewables, the development of novel techniques for clean combustion of fossil fuels is appreciated. Forced by the simultaneous increased pressure of strict emissions regulations and the target of limiting the global warming to 2 °C, gas turbine manufacturers developed novel combustion techniques for clean power production in gas turbines as per the present review study. These novel techniques depend either on modification in the existing combustion system or developing novel burners for clean power production. In this review, different clean combustion techniques are presented including flame type variability, burner design, and fuel and oxidizer flexibility. The combustion and emission characteristics of different flame types including non-premixed/premixed, moderate or intense low-oxygen dilution (MILD) flameless combustion, colorless distributed combustion (CDC), and low-swirl injector (LSI) combustion flames are presented with their limitations for applications. Novel burner designs for clean burning in gas turbines are investigated in detail including swirl stabilized, dry low NOx (DLN), and dry low emission (DLE), catalytic combustion, perforated plate, environmental vortex (EV), sequential environmental vortex (SEV), advanced environmental vortex (AEV), and lean direct injection (LDI) micromixer burners. As an effective technique to control combustion instabilities within the gas turbine combustor, a fuel flexibility approach is studied, considering mainly hydrogen-enriched combustion and the associated concerns about the fuel variability technique. An oxidizer flexibility approach in gas turbines is also studied under a premixed combustion mode considering lean premixed (LPM) air combustion and oxy-fuel combustion, and both techniques are compared in terms of performance and emissions. Finally, the feasibility of the different clean combustion techniques is discussed along with the available market products utilizing such novel technologies.
Studies on the prevalence and virulence genes of Klebsiella mastitis pathogens in a buffalo population are undocumented. Also, the association of rmpA kfu, uge, magA, Aerobactin, K1 and K2 virulent ...factors with K. pneumoniae buffalo, and cow mastitis is unreported. The virulence of K. pneumoniae was evaluated through both phenotypic and molecular assays. In vivo virulence was assessed by the Vero cell cytotoxicity, suckling mouse assay and mice lethality test. Antimicrobial susceptibility was tested by disk diffusion method. The 45 K. pneumoniae isolates from buffalo (n = 10/232) and cow (n = 35/293) milk were isolated (45/525; 8·6%) and screened via PCR for seven virulence genes encoding uridine diphosphate galactose 4 epimerase encoding gene responsible for capsule and smooth lipopolysaccharide synthesis (uge), siderophores (kfu and aerobactin), protectines or invasins (rmpA and magA), and the capsule and hypermucoviscosity (K1 and K2). The most common virulence genes were rmpA, kfu, uge, and magA (77·8% each). Aerobactin and K1 genes were found at medium rates of 66·7% each and K2 (55·6%). The Vero cell cytotoxicity and LD (50) in mice were found in 100% of isolates. A multidrug resistance pattern was observed for 40% of the antimicrobials. The distribution of virulence profiles indicate a role of rmpA, kfu, uge, magA, Aerobactin, and K1 and K2 in pathogenicity of K. pneumoniae in udder infections and invasiveness, and constitutes a threat for vulnerable animals, even more if they are in combination with antibiotic resistance.
To cope with water crisis, wastewater reuse has been introduced as a potential source for irrigation. On the other hand, irrigation with wastewater may negatively affect the surroundings. In this ...study, reed plant (Phragmits australis) and its biochar were tested as low-cost treatments to enhance the efficiency of wastewater reclamation in wetlands within only 72 h. The investigated water was of low irrigation quality and exhibited high contents of BOD
and fecal coliform. Moreover, this water contained high levels of soluble cations and anions; besides, being marginally contaminated with Cu, Mn and Cd. After 2 days in the sedimentation unit, wastewater was subjected to three reclamation treatments in parallel (each lasted for 24 h): (1) a "sand & gravel bed", (2) "reed plants grown on a sand & gravel bed" and (3) "biochar + a sand & gravel bed". The results showed that all treatments decreased BOD
, fecal coliform, total cations and anions, with superiority for the second and third treatments. The levels of the potentially toxic elements also decreased to values within the permissible levels. Although the aforementioned wastewater treatment processes upgraded the quality of this water, it remained in the poor grade. Biochar or reed plants grown on sand and gravel beds significantly improved wastewater quality to the medium quality grade, with superiority for biochar treatment. In conclusion, investigated treatments are guaranteed in wetlands for wastewater reclamation; yet, further protocols should be followed to achieve safe handling of this water and attain the sustainable goals.
A comprehensive body of scientific evidence indicates that rhizobial bacteria and melatonin enhance salt tolerance of crop plants. The overall goal of this research was to evaluate the ability of ...Rhizobium leguminoserum bv phaseoli to suppress salinity stress impacts in common bean treated with melatonin. Treatments included bacterial inoculations (inoculated (RI) and non-inoculated (NI)), different salinity levels (non-saline (NS), 4 (S1) and 8 (S2) dS m
of NaCl) and priming (dry (PD), melatonin (PM100) and hydro (PH) priming) with six replications in growing media containing sterile sand and perlite (1:1). The results showed that the bacterial strain had the ability to produce indole acetic acid (IAA), ACC deaminase and siderophore. Plants exposed to salinity stress indicated a significant decline in growth, yield, yield components, nitrogen fixation and selective transport (ST), while showed a significant increase in sodium uptake. However, the combination of PM100 and RI treatments by improving growth, photosynthesis rate and nitrogen fixation positively influenced plant performance in saline conditions. The combined treatment declined the negative impacts of salinity by improving the potassium translocation, potassium to sodium ratio in the shoot and root and ST. In conclusion, the combination of melatonin and ACC deaminase producing rhizobium mitigated the negative effects of salinity. This result is attributed to the increased ST and decreased sodium uptake, which significantly reduced the accumulation of sodium ions in shoot.
Transcatheter aortic valve implantation (TAVI) has become a well‐established treatment option for elderly patients with symptomatic severe aortic stenosis. Coronary artery anomalies are an infrequent ...finding and there have only been few anecdotal reports of patients with coronary anomalies treated with TAVI. We here present a comprehensive overview of existing reports in addition to an own case series to facilitate better understanding of this potentially challenging clinical scenario.
Purpose This study aims to focus on the main materials used in consolidation processes of illuminated paper manuscripts and leather binding. Design/methodology/approach For each material, chemical ...structure, chemical composition, molecular formula, solubility, advantages, disadvantages and its role in treatment process are presented. Findings This study concluded that carboxy methyl cellulose, hydroxy propyl cellulose, methyl cellulose, cellulose acetate, nanocrystalline cellulose, funori, sturgeon glue, poly vinyl alcohol, chitosan, chitosan nanoparticles (NPs), gelatin, aquazol, paraloid B72 and hydroxyapatite NPs were the most common and important materials used for the consolidation of illuminated paper manuscripts. For the leather bindings, hydroxy propyl cellulose, polyethylene glycol, oligomeric melamine-formaldehyde resin, acrylic wax SC6000, pliantex, paraloid B67 and B72, silicone oil and collagen NPs are the most consolidants used. Originality/value Illuminated paper manuscripts with leather binding are considered one of the most important objects in libraries, museums and storehouses. The uncontrolled conditions and other deterioration factors inside the libraries and storehouses lead to degradation of these artifacts. The brittleness, fragility and weakness are considered the most common deterioration aspects of illuminated paper manuscripts and leather binding. Therefore, the consolidation process became vital and important to solve this problem. This study presents the main materials used for consolidation process of illuminated paper manuscripts and leather bindings.
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