The present study reports the titanium dioxide(TiO_(2))films synthesized from TiCl3 precursor on ITO glass substrates using two electrochemical techniques,namely direct electro-deposition(DE)and pulse electro-depositi...The present study reports the titanium dioxide(TiO_(2))films synthesized from TiCl3 precursor on ITO glass substrates using two electrochemical techniques,namely direct electro-deposition(DE)and pulse electro-deposition(PE).The synthesis potential during the time-on(Ton)period was fixed at-1.5 V.However,the open-circuit potential was applied during the time-off(Toff)period.The effect of the technique of electro-deposition and Toff duration on the properties of TiO_(2)films and their photoelectron-catalytic activity were investigated.The obtained films were investigated by X-ray diffraction(XRD),scanning electron microscopy(SEM),UV-VIS spectrometer,and photocurrent measurement respectively.It is found that the use of the PE technique at different Toff improves the properties of TiO_(2)films compared to the DE technique.The XRD patterns show the anatase phase with a marked preferential orientation along the(101)direction for all samples.From the SEM analysis,it is seen a significant change from big multigrain agglomerates at DE to a dense film structure and small multigrain agglomerates at different Toff.As the Toff decreases from 3 s to 1 s,the photocurrent response rises and reaches a high value of about 12 m A/cm^(2).Compared with DE,and under UV light the photocatalytic property of TiO_(2)film synthesis via PE has been improved in the degradation of methyl orange(MO).Finally,the films deposited at low Toff(Toff=1 s)show a faster degradation of MO.展开更多
In the present paper, a study of the productivity of oocytes in 402 female individuals of the horse mackerel, Trachurus trachurus for an interval of fork length （LF） between 14 cm and 20 cm, in stage IV （pre-spawn...In the present paper, a study of the productivity of oocytes in 402 female individuals of the horse mackerel, Trachurus trachurus for an interval of fork length （LF） between 14 cm and 20 cm, in stage IV （pre-spawning） and V （spawning） was performed to estimate the fecundity rate in Oran Bay （Algerian western coast） since October 2008 to April 2009. Total fecundity （absolute and relative） were calculated using fish length, weight and eviscerated weight of gonads. Absolute fecundity by size class oscillates from 33,375 to 56,391 eggs with an average of 48,686 ±11,470. The relative fecundity ranges from 34,802 to 139,636 eggs per 100 g body weight with an average of 96,955 ± 33,814 and it is varying between 15,544 and 46,561 per gram of gonad with an average of 28,595 ±20,251. The distribution of oocytes shows that stages I and II are presented throughout the spawning season and they constitute a stockpile for subsequent clutches.展开更多
The present study focused on the evaluation of the contamination by three heavy metals （Cd, Cu and Zn） of a bony fish, Mullus surmuletus L., 1758, caught in the Bay of Oran. This reflects the quality of fish habitat...The present study focused on the evaluation of the contamination by three heavy metals （Cd, Cu and Zn） of a bony fish, Mullus surmuletus L., 1758, caught in the Bay of Oran. This reflects the quality of fish habitat as species common Algerian coastal waters and enjoyed by a large fish-eating population. Monthly sampling was spread over a period of six months （December 2011-May 2012）. Given their physiological importance in the body, muscle, liver and gonads were targeted. Metal concentrations were determined by atomic absorption spectrophotometry in flame depends on three parameters （sex, size and month）. It appears from this study that the target organs of rouget （M. surmuletus） accumulate three metal pollutants sought. The highest values are those of zinc, copper and cadmium are at concentrations at least important. The results, statistically treated, showed no significant difference between the concentrations of trace metals both sexes and at all three organs considered. The average dose of heavy metals found in the mullet compared to those provided by the literature relating to DMA （Maximum Allowable Doses）, are not worrisome. Concentration levels of toxic metals reflect a certain metal pollution in the Bay of Oran.展开更多
This work aims to the assessment of marine pollution in the Bay of Oran, including zinc, copper, iron and lead. These toxic elements represent a real danger to living organisms. Many factors have increased the marine ...This work aims to the assessment of marine pollution in the Bay of Oran, including zinc, copper, iron and lead. These toxic elements represent a real danger to living organisms. Many factors have increased the marine pollution and marine traffic including the transport of hydrocarbons, industrial and domestic discharges and fishing activities, etc. This study shows essentially the bioconcentration of heavy metals in the species Mytilus galloprovincialis, these filter bivalves have a broad geographical distribution in our study area, so they allow us to better estimate the degree of pollution at the Bay of Oran. The study of changes in metal concentrations has marked some important points for, the four metallic elements are present in the flesh of mussels analyzed at the port of Oran. This study is part of assessment of pollution at the coast of western Algeria to protect the marine environment.展开更多
Petroleum contaminants caused great damages to environment and human health.Among,the port of Oran is subject of pollution mainly by PAHs(Polycyclic Aromatic Hydrocarbons)as a result of the large flow of ships.Thus bi...Petroleum contaminants caused great damages to environment and human health.Among,the port of Oran is subject of pollution mainly by PAHs(Polycyclic Aromatic Hydrocarbons)as a result of the large flow of ships.Thus bioremediation by indigenous microorganisms is an important means for their reduction and elimination.In the present work,a hydrocarbonoclastic bacterium strain SP49F2 was considered,firstly isolated from the contaminated marine sediments and seawater at the port of Oran(Algeria),using Bushnell-Hass mineral salt medium,and identified on the basis of morphological and biochemical characteristics and molecular tools by analysis of partial 16S rRNA gene sequence,using the Basic Local Alignment Search Tool program on the data base of NCBI(National Centre for Biotechnology Information),and the EzBioCloud 16S rRNA database.Kinetic of growth of this isolate on crude oil during 20 days of culture was studied at temperature 25℃,3%(w/v)of NaCl concentration and pH 7,at 140 rpm(Revolutions Per Minute).Strain SP49F2 was identified molecularly as Acinetobacter johnsonii,and might support high concentrations of crude oil(up to 10%,v/v).Results of growth kinetic on crude oil as sole energy and carbon source by the isolate strain showed that the stationary phase was attained at day 12.Thus,train Acinetobacter johnsonii SP49F2 could efficiently utilize crude oil as its sole carbon and energy source,and could be used as a wonderful native biological alternative for the bioremediation of the port of Oran,and marine area polluted by petroleum hydrocarbons,as an eco-friendly efficacy degrader,and may be suitable for biotechnological applications.展开更多
Essential oil from the leaves of Pistacia lentiscus L. growing in the Oran region in the west of Algeria was obtained by hydrodistillation with a 1.26 % yield on a dry weight basis. Spectrophotometric analyses were em...Essential oil from the leaves of Pistacia lentiscus L. growing in the Oran region in the west of Algeria was obtained by hydrodistillation with a 1.26 % yield on a dry weight basis. Spectrophotometric analyses were employed to highlight the scavenger capacity of this oil using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) test. Twenty compounds were identified by GC and CG/MS analyses, and the main part of the compounds of the oil was terpinene-4-ol (41.24%) and α-terpineol (7.31%), α-pinene (9.48%), limonene (09.11%), β-myrcene (10.5%), p-cymene (8.67%) and α-phellandrene (2.20%), β-caryophyllene (12.62%) as major compounds. The DPPH test shows that Pistacia lentiscus essential oil possesses antiradical activity. A linear correlation (correlation coefficient R<sup>2</sup> = 0.995, P Pistacia lentiscus essential oil.展开更多
The present study focuses on the flow of a yield-stress(Bingham)nanofluid,consisting of suspended Fe3O4 nanoparticles,subjected to a magnetic field in a backward-facing step duct(BFS)configuration.The duct is equipped...The present study focuses on the flow of a yield-stress(Bingham)nanofluid,consisting of suspended Fe3O4 nanoparticles,subjected to a magnetic field in a backward-facing step duct(BFS)configuration.The duct is equipped with a cylindrical obstacle,where the lower wall is kept at a constant temperature.The yield-stress nanofluid enters this duct at a cold temperature with fully developed velocity.The aim of the present investigation is to explore the influence of flow velocity(Re=10 to 200),nanoparticle concentration(ϕ=0 to 0.1),magnetic field intensity(Ha=0 to 100),and its inclination angle(γ=0 to 90)and nanofluid yield stress(Bn=0 to 20)on the thermal and hydrodynamic efficiency inside the backward-facing step.The numerical results have been obtained by resolving the momentum and energy balance equations using the Galerkin finite element method.The obtained results have indicated that an increase in Reynolds number and nanoparticle volume fraction enhances heat transfer.In contrast,a significant reduction is observed with an increase in Hartmann and Bingham numbers,resulting in quasi-immobilization of the fluid under the magnetic influence and radical solidification of this type of fluid,accompanied by the suppression of the vortex zone downstream of the cylindrical obstacle.This study sheds light on the complexity of this magnetically influenced fluid,with potential implications in various engineering and materials science fields.展开更多
The objective of this study is to propose an optimal plant design for blue hydrogen production aboard a liquefiednatural gas(LNG)carrier.This investigation focuses on integrating two distinct processes—steam methaner...The objective of this study is to propose an optimal plant design for blue hydrogen production aboard a liquefiednatural gas(LNG)carrier.This investigation focuses on integrating two distinct processes—steam methanereforming(SMR)and ship-based carbon capture(SBCC).The first refers to the common practice used to obtainhydrogen from methane(often derived from natural gas),where steam reacts with methane to produce hydrogenand carbon dioxide(CO_(2)).The second refers to capturing the CO_(2) generated during the SMR process on boardships.By capturing and storing the carbon emissions,the process significantly reduces its environmental impact,making the hydrogen production“blue,”as opposed to“grey”(which involves CO_(2) emissions without capture).For the SMR process,the analysis reveals that increasing the reformer temperature enhances both the processperformance and CO_(2) emissions.Conversely,a higher steam-to-carbon(s/c)ratio reduces hydrogen yield,therebydecreasing thermal efficiency.The study also shows that preheating the air and boil-off gas(BOG)before theyenter the combustion chamber boosts overall efficiency and curtails CO_(2) emissions.In the SBCC process,puremonoethanolamine(MEA)is employed to capture the CO_(2) generated by the exhaust gases from the SMR process.The results indicate that with a 90%CO_(2) capture rate,the associated heat consumption amounts to 4.6 MJ perkilogram of CO_(2) captured.This combined approach offers a viable pathway to produce blue hydrogen on LNGcarriers while significantly reducing the carbon footprint.展开更多
This work investigates the potential of low-pressure,medium-speed dual-fuel engines for cleaner maritime transportation.The thermodynamic performance of these engines is explored using three alternative fuels:liquefie...This work investigates the potential of low-pressure,medium-speed dual-fuel engines for cleaner maritime transportation.The thermodynamic performance of these engines is explored using three alternative fuels:liquefied natural gas(LNG),methanol,and ammonia.A parametric analysis examines the effect of adjustments to key engine parameters(compression ratio,boost pressure,and air-fuel ratio)on performance.Results show an initial improvement in performance with an increase in compression ratio,which reaches a peak and then declines.Similarly,increases in boost pressure and air-fuel ratio lead to linear performance gains.However,insufficient cooling reduces the amount of fuel burned,which hinders performance.Exergy analysis reveals significant exergy destruction within the engine,which ranges from 69.96%(methanol)to 78.48%(LNG).Notably,the combustion process is the leading cause of exergy loss.Among the fuels tested,methanol exhibits the lowest combustion-related exergy destruction(56.41%),followed by ammonia(62.12%)and LNG(73.77%).These findings suggest that methanol is a promising near-term alternative to LNG for marine fuel applications.展开更多
Understanding plant community assembly is crucial for effective ecosystem conservation and restoration.The ecological filter framework describes community assembly as a process shaped by dispersal,environmental,and bi...Understanding plant community assembly is crucial for effective ecosystem conservation and restoration.The ecological filter framework describes community assembly as a process shaped by dispersal,environmental,and biotic filters.Additionally,functional traits and phylogenetic relationships are increasingly recognized as important factors influencing species coexistence and community structure.However,both the ecological filter framework and the roles of functional traits and phylogeny in community assembly remain underexplored in the Algerian steppes—particularly in the El Bayadh region,where ongoing vegetation degradation threatens ecosystem stability.This study applied Hierarchical Modeling of Species Communities(HMSC)as an integrative approach to assess how ecological filters influence plant community assembly in the El Bayadh steppe and to evaluate the roles of functional traits and phylogenetic relationships in this process.Environmental data—including soil properties,topography,precipitation,and land use types(grazing and exclosure)—were collected across 50 plots in April and October,2023,along with functional traits from 24 species.These traits include root length,leaf area,specific leaf area,clonality,life history,and seed mass.HMSC results revealed that soil properties and precipitation were the primary drivers of community structure,while sand height and elevation had a moderate influence.In contrast,competition and grazing played relatively minor roles.Species responses to environmental covariates were heterogeneous:soil fertility and texture had mixed effects,benefiting some species while limiting others;sand encroachment and precipitation variability generally had negative impacts,whereas grazing exclusion favored many species.A weak phylogenetic signal was recorded,indicating that community assembly was driven more by environmental filtering than by shared evolutionary history.Functional trait responses to environmental variation reflected plant strategies that balanced resource acquisition and conservation.Specifically,seed mass,leaf area,and root length increased under higher soil moisture and nutrient availability but declined in response to salinity,precipitation variability,and sand height.Clonality and perennial life history traits enhanced the survival of plant species under harsh conditions.Overall,this study provides a holistic understanding of community assembly processes in the El Bayadh steppe and offers valuable insights for ecosystem management and restoration in arid and degraded ecosystem environments.展开更多
Exploiting remote sensing data is a promising approach to estimate surface solar irradiance(SSI).In this study,we propose a method to estimate global SSI using a lookup table and Landsat data.Despite the low temporal ...Exploiting remote sensing data is a promising approach to estimate surface solar irradiance(SSI).In this study,we propose a method to estimate global SSI using a lookup table and Landsat data.Despite the low temporal resolution of the data used,the developed method produces SSI maps with adequate spatial resolution.It combines physical parameters extracted from Landsat metadata files with the physical laws governing global solar irradiance,its transmission through the atmosphere,and surface reflectance.The results obtained are compared with those in the literature,particularly one study that uses Meteosat data and two others that use radiometric spectral and temporal models.Additionally,experiments are conducted at three sites in Algeria:Oran,In Amenas,and Tamenghasset.The findings indicate that the proposed approach aligns with the tested literature methods while providing SSI maps with superior spatial resolution.Furthermore,the obtained solar irradiances exhibit a root mean square error of approximately 190 W m^(−2)μm^(−1) compared with those of the Bird and Riordan spectral model,and approximately 50 W m^(−2) compared with the results from the Bird and Hulstrom temporal model,and are also comparable to the results of previous studies.展开更多
The hydrodynamic performance of high-speed planing hulls has gained considerable interest,with recent advancements in computational fluid dynamics and hull design techniques enhancing the understanding of planing hull...The hydrodynamic performance of high-speed planing hulls has gained considerable interest,with recent advancements in computational fluid dynamics and hull design techniques enhancing the understanding of planing hull hydrodynamics.In this study,we conducted a numerical investigation using the Reynolds-averaged Navier-Stokes approach with overset grids to capture large motions at high speeds.This study aims to improve the hydrodynamic performances of planing hulls,specifically focusing on total resistance,trim,and sinkage.The initial Fridsma hull with a deadrise angle of 20°has been used for validation,demonstrating good agreement with measurements at different Froude numbers.Subsequently,new configurations based on the Fridsma hull have been designed by varying the deadrise angle,number of chines,and transverse steps.Our findings reveal a correlation between the deadrise angle,the number of chines,and the Froude number.As the deadrise angle increases,total resistance also increases.Additionally,a single chine yields superior results at higher Froude numbers,while multiple chines offer advantages at lower values.The introduction of transverse steps consistently increases total resistance,highlighting their role in improving planing hull performance.This research not only offers valuable insights into planing hull design but also leverages state-of-the-art numerical methods to advance the understanding of hydrodynamic behaviors at high ship speeds.展开更多
Acute myocardial infarction in women during childbearing age is rare. We report a case of a 40-year-old female patient with no history or cardiovascular risk factors, 24-week</span><span style="font-fami...Acute myocardial infarction in women during childbearing age is rare. We report a case of a 40-year-old female patient with no history or cardiovascular risk factors, 24-week</span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">pregnant who presented with acute coronary syndrome with an ST-elevation anterior extended complicated by cardiogenic shock. Cardiac ultrasound showed systolic dysfunction of the left ventricle at 30%. Emergency coronary angiography revealed subocclusion of the proximal anterior interventricular artery. We performed a primary angioplasty with placement of a stent after balloon predilation with a satisfactory agiographic result and an improvement in the hemodynamic state. The patient gave birth by cesarean section at 30 weeks of pregnancy after a pocket rupture of infectious waters. The newborn died after 72 hours. After 6 years of evolution, the patient remained asymptomatic under medal treatment.展开更多
The objectif in the present study is description of a new species of Sphincteristomum Oshmarin, Mamaev & Parukhin 1961, named Sphincteristomum mediterraneae, which is described in Oran bay, Algeria. It parasitizes...The objectif in the present study is description of a new species of Sphincteristomum Oshmarin, Mamaev & Parukhin 1961, named Sphincteristomum mediterraneae, which is described in Oran bay, Algeria. It parasitizes the intestine of naturally infected Pagellus erythrinus, Teleostei, Sparidae. The Pagellus erythrinus is in important food fish in the Mediterranean. This genus belongs to the family Apocreadiidae, sub family Schistorchiinae, characterized by an obvious oral muscular sphincter, into a large oral sucker, a disc-shaped acetabulum under the intestinal bifurcation, an ocular pigment scattered in the forebody, a sequence ovary and two testes in tandem and a I-shaped excretory bladder. In the new species, the digestive apparatus displays a hexagonal peculiar aperture, followed by a longitudinal slit, a waved pharynx, two long and broad caeca, with a thick internal wall of endothelial cells. Each caecum has a sub terminal anus. The female genital apparatus displays a transversally elongated ovary, under the acetabulum. On the side of the ovary, there is a small Mehlis gland. Under the ovary, there are two transverse converging vitelloducts. Lateral and extracaecal vitelline follicles, are spread near the caeca. They converge in the hindbody. The relatively short uterus is preovarian, mainly. It contains few large yellow eggs. Its distal part is creased transversally, just before ending in genital atrium. The male genital apparatus shows two lobed heart-shaped testes, post ovarian, in tandem. From the anterior edge of each testis, two spermiducts climb up and converge into a naked, curved or sinuous seminal vesicle, followed by a short prostate surrounded by few prostatic cells, and a narrow ejaculatory duct, opening in genital atrium. The genital pore is close to the acetabulum and the intestinal bifurcation. No cirrus pouch. The excretory system shows a relatively short tubular I-shaped bladder, reaching the inferior level of the second testis. Two thin excretory arms are seen until the forebody of the worms. The terminal excretory pore is closed by a small sphincter. In the same P. eryrthrinus, immature worms devoid of genitalia, young worms with genitalia devoid of eggs and ovigerous worms, live together with senile specimens. These last ones show still, oral sucker, diffuse vitelline follicles and very small and scattered ocular pigment.展开更多
AIM： To evaluate determinants of infammatory mark-ers in chronic renal failure patients according to the level of glomerular fltration rate. METHODS： One hundred ffty four patients （Age： 44 ± 06 years; male/f...AIM： To evaluate determinants of infammatory mark-ers in chronic renal failure patients according to the level of glomerular fltration rate. METHODS： One hundred ffty four patients （Age： 44 ± 06 years; male/female： 66/88） with chronic renal fail-ure （CRF） were divided into 6 groups according to the National Kidney Foundation （NKF） classification. They included 28 primary stage renal failure patients （CRF 1）, 28 moderate stage renal failure patients （CRF 2）,28 severe stage renal failure patients （CRF 3）, 18 end-stage renal failure patients （CRF 4）, 40 hemodialysis （HD） patients, and 12 peritoneal dialysis （PD） patients. Tumor necrosis factor-α （TNF-α）, interleukin-1β （IL-1β）, interleukin-6 （IL-6） and C-reactive protein （CRP） were analyzed by immunosorbent assay kit （ELISA） （Cayman Chemical’s ACETM EIA kit）. Immunoassay methods were used for total homocysteine （tHcy） （fuorescence polarization immunoanalysis HPLC, PerkinEmer 200 series）, transferrin （MININEPHTM human transferin kit： ZK070.R）, ferritin （ADVIA Centaur ） and fbrinogen analysis （ACL 200）. Differences between groups were performed using SPSS 20.0 and data are expressed as the mean ± SD.RESULTS： Results showed that in comparison with CRF 1 group and other groups, TNF-α and IL-6 levels were respectively more elevated in HD （16.38 ± 5.52 pg/mL vs 0.39 ± 0.03 pg/mL, 11.05 ± 3.59 pg/mL vs 8.20 ± 0.22 pg/mL, P 〈 0.001） and PD （14.04 ± 3.40 pg/mL vs 0.39 ± 0.03 pg/mL, 10.15 ± 1.66 pg/mL vs 8.20 ± 0.22 pg/mL, P 〈 0.001）. IL-1β levels were increased in HD （9.63 ± 3.50 pg/mL vs 3.24 ± 0.10 pg/mL, P 〈 0.001） and CRF 4 （7.76 ± 0.66 pg/mL vs 3.24 ± 0.10 pg/mL, P 〈 0.001） patients than in CRF 1 and in the other groups. Plasma tHcy levels were higher in HD （32.27 ± 12.08 μmol/L） and PD （28.37 ± 4.98 μmol/L） patients compared to the other groups of CRF （P 〈 0.001）. The serum CRP level was signifcantly increased in HD （18.17 ± 6.38 mg/L） and PD （17.97 ± 4.85 mg/L） patients compared to the other groups of CRF patients （P 〈 0.001）. The plasma fbrinogen level was more elevated in HD （6.86 ± 1.06 g/L） and CRF 4 （6.05 ± 0.57 g/L） than in the other groups （ P 〈 0.001）. Furthermore; the ferritin level was higher in HD （169.90 ± 62.16 ng/mL） and PD （90.08 ± 22.09 ng/mL） pa-tients compared to the other groups of CRF （P 〈 0.001）. The serum transferrin value was signifcantly decreased especially in PD （1.78 ± 0.21 g/L） compared to the oth-er groups （P 〈 0.001）. We found a negative correlation between glomerular fltration rate （GFR）, TNF-α levels （ r = -0.75, P 〈 0.001）, and tHcy levels （ r = -0.68, P 〈 0.001）. We observed a positive correlation between GFR and transferrin levels （ r = 0.60, P 〈 0.001）. CONCLUSION： CRF was associated with elevated in-flammatory markers. The inflammation was observed at the severe stage of CRF and increases with progres-sion of renal failure.展开更多
CeO2nanoparticles(NPs) were synthesized in alkaline medium via the homogeneous precipitation method and were subsequently calcined at 80 ℃/24 h(assigned as CeO2-80) and 500 ℃/2 h(assigned as CeO2-500). The as-prepar...CeO2nanoparticles(NPs) were synthesized in alkaline medium via the homogeneous precipitation method and were subsequently calcined at 80 ℃/24 h(assigned as CeO2-80) and 500 ℃/2 h(assigned as CeO2-500). The as-prepared materials and the commercial ceria(assigned as CeO2-com) were characterized using TGA-MS, XRD, SEM-EDX, UV-vis DRS and IEP techniques. The photocatalytic performances of all obtained photocatalysts were assessed by the degradation of Congo red azo-dye(CR) under UVAlight irradiation at various environmental key factors(e.g., reaction time and calcination temperature).Results reveal that CeO2compounds crystalize with cubic phase, CeO2-500 exhibits smaller crystallite size(9 nm vs 117 nm) than that of bare CeO2-com. SEM analysis shows that the materials are sphericallike in shape NPs with strong assembly of CeO2NPs observed in the CeO2-500 NPs. EDX analysis confirms the stoichiometry of CeO2NPs. UV-vis DRS measurement reveals that, CeO2-500 NPs exhibits a red-shift of absorption band and a more narrow bandgap(2.6 eV vs 3.20 eV) than that of bare CeO2-com. On the contrary, Urbach energy of Eu is found to be increased from 0.12 eV(CeO2-com) to 0.17 eV(CeO2-500),highlighting an increase of crystalline size and internal microstrain in the CeO2-500 NPs sample. Zeta potential(IEP) of CeO2-500 NPs is found to be 7.2. UVA-light-responsive photocatalytic activity is observed with CeO2-500 NPs at a rate constant of 10×10-3min-1, which is four times higher than that of CeO2-com(Kapp=2.4×10-3min-1) for the degradation of CR. Pseudo-first-order kinetic model gives the best fit. On the basis of the energy band diagram positions, the enhanced photocatalytic performance of CeO2-500 nano-catalyst can be ascribed to O2-, ’OH and R’+as the primary oxidative species involved in the degradation of RC under UVA-light irradiation.展开更多
The aim of this paper is to study the effect of agitator’s types on the turbulent flows in stirred tanks without and with baffles.The hydrodynamics behavior induced by four different agitator’s types:a Rushton turbi...The aim of this paper is to study the effect of agitator’s types on the turbulent flows in stirred tanks without and with baffles.The hydrodynamics behavior induced by four different agitator’s types:a Rushton turbine(RT),a circular blade turbine(CBT),a diverging triangular blade turbine(DTBT)and converging triangular blade turbine(CTBT)are numerically predicted by solving the Navier-Stokes equations and RNGκ–εturbulent model.The simulations are carried out using the Multi Reference Frame(MRF)approach.The numerical results showed good agreement with experiment.We find that the agitator CTBT gives an important profit on the power consumption per report/ratio the others and DTBT give a good reduction of the vortex size of the impeller angles.展开更多
In the present paper, we examine the performance of an efficient type of wave-absorbing porous marine structure under the attack of regular oblique waves by using a Multi-Domain Boundary Element Method(MDBEM). The str...In the present paper, we examine the performance of an efficient type of wave-absorbing porous marine structure under the attack of regular oblique waves by using a Multi-Domain Boundary Element Method(MDBEM). The structure consists of two perforated vertical thin barriers creating what can be called a wave absorbing chamber system. The barriers are surface piercing, thereby eliminating wave overtopping. The problem of the interaction of obliquely incident linear waves upon a pair of perforated barriers is first formulated in the context of linear diffraction theory. The resulting boundary integral equation, which is matched with far-field solutions presented in terms of analytical series with unknown coefficients, as well as the appropriate boundary conditions at the free surface, seabed, and barriers, is then solved numerically using MDBEM. Dissipation of the wave energy due to the presence of the perforated barriers is represented by a simple yet effective relation in terms of the porosity parameter appropriate for thin perforated walls. The results are presented in terms of reflection and transmission coefficients. The effects of the incident wave angles, relative water depths, porosities, depths of the walls, and other major parameters of interest are explored.展开更多
The chemical composition and antimicrobial potential of Cistus munbyi essential oil were studied for the first time. GC and GC–MS analysis revealed 48 compounds representing 96.98% of the oil. Terpinen-4-ol(23.75%), ...The chemical composition and antimicrobial potential of Cistus munbyi essential oil were studied for the first time. GC and GC–MS analysis revealed 48 compounds representing 96.98% of the oil. Terpinen-4-ol(23.75%), meta-Cymene(17.30%), and Sabinene(12.38%)were the major constituents. Antimicrobial activity was evaluated against nine pathogens using the disc diffusion and broth micro-dilution methods. Results show that C.munbyi essential oil possesses strong antimicrobial activity against all strains, regardless if Gram-positive or Gramnegative bacteria, or yeast, with MICs values not exceeding10(mg/ml). In addition to its efficacy, C. munbyi essential oil has an unusual antimicrobial potency which is attributed to its specific chemical composition. Thus, findings presented here suggest that endemic C. munbyi contains a very interesting essential oil that may be valuable in several areas.展开更多
In this paper, reflection and transmission coefficients of regular waves from/through perforated thin walls are investigated. Small scale laboratory tests have been performed in a wave flume firstly with single perfor...In this paper, reflection and transmission coefficients of regular waves from/through perforated thin walls are investigated. Small scale laboratory tests have been performed in a wave flume firstly with single perforated thin Plexiglas plates of various porosities. The plate is placed perpendicular to the flume with the height from the flume bottom to the position above water surface. With this thin wall in the flume wave overtopping is prohibited and incident waves are able to transmit. The porosities of the walls are achieved by perforating the plates with circular holes. Model settings with double perforated walls parallel to each other forming so called chamber system, have been also examined. Several parameters have been used for correlating the laboratory tests’ results. Experimental data are also compared with results from the numerical model by applying the multi-domain boundary element method （MDBEM） with linear wave theory. Wave energy dissipation due to the perforations of the thin wall has been represented by a simple yet effective porosity parameter in the model. The numerical model with the MDBEM has been further validated against the previously published data.展开更多
文摘The present study reports the titanium dioxide(TiO_(2))films synthesized from TiCl3 precursor on ITO glass substrates using two electrochemical techniques,namely direct electro-deposition(DE)and pulse electro-deposition(PE).The synthesis potential during the time-on(Ton)period was fixed at-1.5 V.However,the open-circuit potential was applied during the time-off(Toff)period.The effect of the technique of electro-deposition and Toff duration on the properties of TiO_(2)films and their photoelectron-catalytic activity were investigated.The obtained films were investigated by X-ray diffraction(XRD),scanning electron microscopy(SEM),UV-VIS spectrometer,and photocurrent measurement respectively.It is found that the use of the PE technique at different Toff improves the properties of TiO_(2)films compared to the DE technique.The XRD patterns show the anatase phase with a marked preferential orientation along the(101)direction for all samples.From the SEM analysis,it is seen a significant change from big multigrain agglomerates at DE to a dense film structure and small multigrain agglomerates at different Toff.As the Toff decreases from 3 s to 1 s,the photocurrent response rises and reaches a high value of about 12 m A/cm^(2).Compared with DE,and under UV light the photocatalytic property of TiO_(2)film synthesis via PE has been improved in the degradation of methyl orange(MO).Finally,the films deposited at low Toff(Toff=1 s)show a faster degradation of MO.
文摘In the present paper, a study of the productivity of oocytes in 402 female individuals of the horse mackerel, Trachurus trachurus for an interval of fork length （LF） between 14 cm and 20 cm, in stage IV （pre-spawning） and V （spawning） was performed to estimate the fecundity rate in Oran Bay （Algerian western coast） since October 2008 to April 2009. Total fecundity （absolute and relative） were calculated using fish length, weight and eviscerated weight of gonads. Absolute fecundity by size class oscillates from 33,375 to 56,391 eggs with an average of 48,686 ±11,470. The relative fecundity ranges from 34,802 to 139,636 eggs per 100 g body weight with an average of 96,955 ± 33,814 and it is varying between 15,544 and 46,561 per gram of gonad with an average of 28,595 ±20,251. The distribution of oocytes shows that stages I and II are presented throughout the spawning season and they constitute a stockpile for subsequent clutches.
文摘The present study focused on the evaluation of the contamination by three heavy metals （Cd, Cu and Zn） of a bony fish, Mullus surmuletus L., 1758, caught in the Bay of Oran. This reflects the quality of fish habitat as species common Algerian coastal waters and enjoyed by a large fish-eating population. Monthly sampling was spread over a period of six months （December 2011-May 2012）. Given their physiological importance in the body, muscle, liver and gonads were targeted. Metal concentrations were determined by atomic absorption spectrophotometry in flame depends on three parameters （sex, size and month）. It appears from this study that the target organs of rouget （M. surmuletus） accumulate three metal pollutants sought. The highest values are those of zinc, copper and cadmium are at concentrations at least important. The results, statistically treated, showed no significant difference between the concentrations of trace metals both sexes and at all three organs considered. The average dose of heavy metals found in the mullet compared to those provided by the literature relating to DMA （Maximum Allowable Doses）, are not worrisome. Concentration levels of toxic metals reflect a certain metal pollution in the Bay of Oran.
文摘This work aims to the assessment of marine pollution in the Bay of Oran, including zinc, copper, iron and lead. These toxic elements represent a real danger to living organisms. Many factors have increased the marine pollution and marine traffic including the transport of hydrocarbons, industrial and domestic discharges and fishing activities, etc. This study shows essentially the bioconcentration of heavy metals in the species Mytilus galloprovincialis, these filter bivalves have a broad geographical distribution in our study area, so they allow us to better estimate the degree of pollution at the Bay of Oran. The study of changes in metal concentrations has marked some important points for, the four metallic elements are present in the flesh of mussels analyzed at the port of Oran. This study is part of assessment of pollution at the coast of western Algeria to protect the marine environment.
文摘Petroleum contaminants caused great damages to environment and human health.Among,the port of Oran is subject of pollution mainly by PAHs(Polycyclic Aromatic Hydrocarbons)as a result of the large flow of ships.Thus bioremediation by indigenous microorganisms is an important means for their reduction and elimination.In the present work,a hydrocarbonoclastic bacterium strain SP49F2 was considered,firstly isolated from the contaminated marine sediments and seawater at the port of Oran(Algeria),using Bushnell-Hass mineral salt medium,and identified on the basis of morphological and biochemical characteristics and molecular tools by analysis of partial 16S rRNA gene sequence,using the Basic Local Alignment Search Tool program on the data base of NCBI(National Centre for Biotechnology Information),and the EzBioCloud 16S rRNA database.Kinetic of growth of this isolate on crude oil during 20 days of culture was studied at temperature 25℃,3%(w/v)of NaCl concentration and pH 7,at 140 rpm(Revolutions Per Minute).Strain SP49F2 was identified molecularly as Acinetobacter johnsonii,and might support high concentrations of crude oil(up to 10%,v/v).Results of growth kinetic on crude oil as sole energy and carbon source by the isolate strain showed that the stationary phase was attained at day 12.Thus,train Acinetobacter johnsonii SP49F2 could efficiently utilize crude oil as its sole carbon and energy source,and could be used as a wonderful native biological alternative for the bioremediation of the port of Oran,and marine area polluted by petroleum hydrocarbons,as an eco-friendly efficacy degrader,and may be suitable for biotechnological applications.
文摘Essential oil from the leaves of Pistacia lentiscus L. growing in the Oran region in the west of Algeria was obtained by hydrodistillation with a 1.26 % yield on a dry weight basis. Spectrophotometric analyses were employed to highlight the scavenger capacity of this oil using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) test. Twenty compounds were identified by GC and CG/MS analyses, and the main part of the compounds of the oil was terpinene-4-ol (41.24%) and α-terpineol (7.31%), α-pinene (9.48%), limonene (09.11%), β-myrcene (10.5%), p-cymene (8.67%) and α-phellandrene (2.20%), β-caryophyllene (12.62%) as major compounds. The DPPH test shows that Pistacia lentiscus essential oil possesses antiradical activity. A linear correlation (correlation coefficient R<sup>2</sup> = 0.995, P Pistacia lentiscus essential oil.
文摘The present study focuses on the flow of a yield-stress(Bingham)nanofluid,consisting of suspended Fe3O4 nanoparticles,subjected to a magnetic field in a backward-facing step duct(BFS)configuration.The duct is equipped with a cylindrical obstacle,where the lower wall is kept at a constant temperature.The yield-stress nanofluid enters this duct at a cold temperature with fully developed velocity.The aim of the present investigation is to explore the influence of flow velocity(Re=10 to 200),nanoparticle concentration(ϕ=0 to 0.1),magnetic field intensity(Ha=0 to 100),and its inclination angle(γ=0 to 90)and nanofluid yield stress(Bn=0 to 20)on the thermal and hydrodynamic efficiency inside the backward-facing step.The numerical results have been obtained by resolving the momentum and energy balance equations using the Galerkin finite element method.The obtained results have indicated that an increase in Reynolds number and nanoparticle volume fraction enhances heat transfer.In contrast,a significant reduction is observed with an increase in Hartmann and Bingham numbers,resulting in quasi-immobilization of the fluid under the magnetic influence and radical solidification of this type of fluid,accompanied by the suppression of the vortex zone downstream of the cylindrical obstacle.This study sheds light on the complexity of this magnetically influenced fluid,with potential implications in various engineering and materials science fields.
文摘The objective of this study is to propose an optimal plant design for blue hydrogen production aboard a liquefiednatural gas(LNG)carrier.This investigation focuses on integrating two distinct processes—steam methanereforming(SMR)and ship-based carbon capture(SBCC).The first refers to the common practice used to obtainhydrogen from methane(often derived from natural gas),where steam reacts with methane to produce hydrogenand carbon dioxide(CO_(2)).The second refers to capturing the CO_(2) generated during the SMR process on boardships.By capturing and storing the carbon emissions,the process significantly reduces its environmental impact,making the hydrogen production“blue,”as opposed to“grey”(which involves CO_(2) emissions without capture).For the SMR process,the analysis reveals that increasing the reformer temperature enhances both the processperformance and CO_(2) emissions.Conversely,a higher steam-to-carbon(s/c)ratio reduces hydrogen yield,therebydecreasing thermal efficiency.The study also shows that preheating the air and boil-off gas(BOG)before theyenter the combustion chamber boosts overall efficiency and curtails CO_(2) emissions.In the SBCC process,puremonoethanolamine(MEA)is employed to capture the CO_(2) generated by the exhaust gases from the SMR process.The results indicate that with a 90%CO_(2) capture rate,the associated heat consumption amounts to 4.6 MJ perkilogram of CO_(2) captured.This combined approach offers a viable pathway to produce blue hydrogen on LNGcarriers while significantly reducing the carbon footprint.
文摘This work investigates the potential of low-pressure,medium-speed dual-fuel engines for cleaner maritime transportation.The thermodynamic performance of these engines is explored using three alternative fuels:liquefied natural gas(LNG),methanol,and ammonia.A parametric analysis examines the effect of adjustments to key engine parameters(compression ratio,boost pressure,and air-fuel ratio)on performance.Results show an initial improvement in performance with an increase in compression ratio,which reaches a peak and then declines.Similarly,increases in boost pressure and air-fuel ratio lead to linear performance gains.However,insufficient cooling reduces the amount of fuel burned,which hinders performance.Exergy analysis reveals significant exergy destruction within the engine,which ranges from 69.96%(methanol)to 78.48%(LNG).Notably,the combustion process is the leading cause of exergy loss.Among the fuels tested,methanol exhibits the lowest combustion-related exergy destruction(56.41%),followed by ammonia(62.12%)and LNG(73.77%).These findings suggest that methanol is a promising near-term alternative to LNG for marine fuel applications.
基金supported by the Foundation of the University of Quebec in Abitibi-Témiscamingue(FUQAT)Quebec Research Fund(FRQ)(2021-SE7-282961)。
文摘Understanding plant community assembly is crucial for effective ecosystem conservation and restoration.The ecological filter framework describes community assembly as a process shaped by dispersal,environmental,and biotic filters.Additionally,functional traits and phylogenetic relationships are increasingly recognized as important factors influencing species coexistence and community structure.However,both the ecological filter framework and the roles of functional traits and phylogeny in community assembly remain underexplored in the Algerian steppes—particularly in the El Bayadh region,where ongoing vegetation degradation threatens ecosystem stability.This study applied Hierarchical Modeling of Species Communities(HMSC)as an integrative approach to assess how ecological filters influence plant community assembly in the El Bayadh steppe and to evaluate the roles of functional traits and phylogenetic relationships in this process.Environmental data—including soil properties,topography,precipitation,and land use types(grazing and exclosure)—were collected across 50 plots in April and October,2023,along with functional traits from 24 species.These traits include root length,leaf area,specific leaf area,clonality,life history,and seed mass.HMSC results revealed that soil properties and precipitation were the primary drivers of community structure,while sand height and elevation had a moderate influence.In contrast,competition and grazing played relatively minor roles.Species responses to environmental covariates were heterogeneous:soil fertility and texture had mixed effects,benefiting some species while limiting others;sand encroachment and precipitation variability generally had negative impacts,whereas grazing exclusion favored many species.A weak phylogenetic signal was recorded,indicating that community assembly was driven more by environmental filtering than by shared evolutionary history.Functional trait responses to environmental variation reflected plant strategies that balanced resource acquisition and conservation.Specifically,seed mass,leaf area,and root length increased under higher soil moisture and nutrient availability but declined in response to salinity,precipitation variability,and sand height.Clonality and perennial life history traits enhanced the survival of plant species under harsh conditions.Overall,this study provides a holistic understanding of community assembly processes in the El Bayadh steppe and offers valuable insights for ecosystem management and restoration in arid and degraded ecosystem environments.
基金supported by the Earth Observation Research Department,Centre des Techniques Spatiales(CTS),Algerian Space Agency(ASAL)。
文摘Exploiting remote sensing data is a promising approach to estimate surface solar irradiance(SSI).In this study,we propose a method to estimate global SSI using a lookup table and Landsat data.Despite the low temporal resolution of the data used,the developed method produces SSI maps with adequate spatial resolution.It combines physical parameters extracted from Landsat metadata files with the physical laws governing global solar irradiance,its transmission through the atmosphere,and surface reflectance.The results obtained are compared with those in the literature,particularly one study that uses Meteosat data and two others that use radiometric spectral and temporal models.Additionally,experiments are conducted at three sites in Algeria:Oran,In Amenas,and Tamenghasset.The findings indicate that the proposed approach aligns with the tested literature methods while providing SSI maps with superior spatial resolution.Furthermore,the obtained solar irradiances exhibit a root mean square error of approximately 190 W m^(−2)μm^(−1) compared with those of the Bird and Riordan spectral model,and approximately 50 W m^(−2) compared with the results from the Bird and Hulstrom temporal model,and are also comparable to the results of previous studies.
基金Supported by the UK Department for Transport,as part of the UK Shipping Office for Reducing Emissions(UK SHORE)Programme and the UK Engineering and Physical Sciences Research Council(EPSRC)[grant number EP/Y024605/1].
文摘The hydrodynamic performance of high-speed planing hulls has gained considerable interest,with recent advancements in computational fluid dynamics and hull design techniques enhancing the understanding of planing hull hydrodynamics.In this study,we conducted a numerical investigation using the Reynolds-averaged Navier-Stokes approach with overset grids to capture large motions at high speeds.This study aims to improve the hydrodynamic performances of planing hulls,specifically focusing on total resistance,trim,and sinkage.The initial Fridsma hull with a deadrise angle of 20°has been used for validation,demonstrating good agreement with measurements at different Froude numbers.Subsequently,new configurations based on the Fridsma hull have been designed by varying the deadrise angle,number of chines,and transverse steps.Our findings reveal a correlation between the deadrise angle,the number of chines,and the Froude number.As the deadrise angle increases,total resistance also increases.Additionally,a single chine yields superior results at higher Froude numbers,while multiple chines offer advantages at lower values.The introduction of transverse steps consistently increases total resistance,highlighting their role in improving planing hull performance.This research not only offers valuable insights into planing hull design but also leverages state-of-the-art numerical methods to advance the understanding of hydrodynamic behaviors at high ship speeds.
文摘Acute myocardial infarction in women during childbearing age is rare. We report a case of a 40-year-old female patient with no history or cardiovascular risk factors, 24-week</span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">pregnant who presented with acute coronary syndrome with an ST-elevation anterior extended complicated by cardiogenic shock. Cardiac ultrasound showed systolic dysfunction of the left ventricle at 30%. Emergency coronary angiography revealed subocclusion of the proximal anterior interventricular artery. We performed a primary angioplasty with placement of a stent after balloon predilation with a satisfactory agiographic result and an improvement in the hemodynamic state. The patient gave birth by cesarean section at 30 weeks of pregnancy after a pocket rupture of infectious waters. The newborn died after 72 hours. After 6 years of evolution, the patient remained asymptomatic under medal treatment.
文摘The objectif in the present study is description of a new species of Sphincteristomum Oshmarin, Mamaev & Parukhin 1961, named Sphincteristomum mediterraneae, which is described in Oran bay, Algeria. It parasitizes the intestine of naturally infected Pagellus erythrinus, Teleostei, Sparidae. The Pagellus erythrinus is in important food fish in the Mediterranean. This genus belongs to the family Apocreadiidae, sub family Schistorchiinae, characterized by an obvious oral muscular sphincter, into a large oral sucker, a disc-shaped acetabulum under the intestinal bifurcation, an ocular pigment scattered in the forebody, a sequence ovary and two testes in tandem and a I-shaped excretory bladder. In the new species, the digestive apparatus displays a hexagonal peculiar aperture, followed by a longitudinal slit, a waved pharynx, two long and broad caeca, with a thick internal wall of endothelial cells. Each caecum has a sub terminal anus. The female genital apparatus displays a transversally elongated ovary, under the acetabulum. On the side of the ovary, there is a small Mehlis gland. Under the ovary, there are two transverse converging vitelloducts. Lateral and extracaecal vitelline follicles, are spread near the caeca. They converge in the hindbody. The relatively short uterus is preovarian, mainly. It contains few large yellow eggs. Its distal part is creased transversally, just before ending in genital atrium. The male genital apparatus shows two lobed heart-shaped testes, post ovarian, in tandem. From the anterior edge of each testis, two spermiducts climb up and converge into a naked, curved or sinuous seminal vesicle, followed by a short prostate surrounded by few prostatic cells, and a narrow ejaculatory duct, opening in genital atrium. The genital pore is close to the acetabulum and the intestinal bifurcation. No cirrus pouch. The excretory system shows a relatively short tubular I-shaped bladder, reaching the inferior level of the second testis. Two thin excretory arms are seen until the forebody of the worms. The terminal excretory pore is closed by a small sphincter. In the same P. eryrthrinus, immature worms devoid of genitalia, young worms with genitalia devoid of eggs and ovigerous worms, live together with senile specimens. These last ones show still, oral sucker, diffuse vitelline follicles and very small and scattered ocular pigment.
文摘AIM： To evaluate determinants of infammatory mark-ers in chronic renal failure patients according to the level of glomerular fltration rate. METHODS： One hundred ffty four patients （Age： 44 ± 06 years; male/female： 66/88） with chronic renal fail-ure （CRF） were divided into 6 groups according to the National Kidney Foundation （NKF） classification. They included 28 primary stage renal failure patients （CRF 1）, 28 moderate stage renal failure patients （CRF 2）,28 severe stage renal failure patients （CRF 3）, 18 end-stage renal failure patients （CRF 4）, 40 hemodialysis （HD） patients, and 12 peritoneal dialysis （PD） patients. Tumor necrosis factor-α （TNF-α）, interleukin-1β （IL-1β）, interleukin-6 （IL-6） and C-reactive protein （CRP） were analyzed by immunosorbent assay kit （ELISA） （Cayman Chemical’s ACETM EIA kit）. Immunoassay methods were used for total homocysteine （tHcy） （fuorescence polarization immunoanalysis HPLC, PerkinEmer 200 series）, transferrin （MININEPHTM human transferin kit： ZK070.R）, ferritin （ADVIA Centaur ） and fbrinogen analysis （ACL 200）. Differences between groups were performed using SPSS 20.0 and data are expressed as the mean ± SD.RESULTS： Results showed that in comparison with CRF 1 group and other groups, TNF-α and IL-6 levels were respectively more elevated in HD （16.38 ± 5.52 pg/mL vs 0.39 ± 0.03 pg/mL, 11.05 ± 3.59 pg/mL vs 8.20 ± 0.22 pg/mL, P 〈 0.001） and PD （14.04 ± 3.40 pg/mL vs 0.39 ± 0.03 pg/mL, 10.15 ± 1.66 pg/mL vs 8.20 ± 0.22 pg/mL, P 〈 0.001）. IL-1β levels were increased in HD （9.63 ± 3.50 pg/mL vs 3.24 ± 0.10 pg/mL, P 〈 0.001） and CRF 4 （7.76 ± 0.66 pg/mL vs 3.24 ± 0.10 pg/mL, P 〈 0.001） patients than in CRF 1 and in the other groups. Plasma tHcy levels were higher in HD （32.27 ± 12.08 μmol/L） and PD （28.37 ± 4.98 μmol/L） patients compared to the other groups of CRF （P 〈 0.001）. The serum CRP level was signifcantly increased in HD （18.17 ± 6.38 mg/L） and PD （17.97 ± 4.85 mg/L） patients compared to the other groups of CRF patients （P 〈 0.001）. The plasma fbrinogen level was more elevated in HD （6.86 ± 1.06 g/L） and CRF 4 （6.05 ± 0.57 g/L） than in the other groups （ P 〈 0.001）. Furthermore; the ferritin level was higher in HD （169.90 ± 62.16 ng/mL） and PD （90.08 ± 22.09 ng/mL） pa-tients compared to the other groups of CRF （P 〈 0.001）. The serum transferrin value was signifcantly decreased especially in PD （1.78 ± 0.21 g/L） compared to the oth-er groups （P 〈 0.001）. We found a negative correlation between glomerular fltration rate （GFR）, TNF-α levels （ r = -0.75, P 〈 0.001）, and tHcy levels （ r = -0.68, P 〈 0.001）. We observed a positive correlation between GFR and transferrin levels （ r = 0.60, P 〈 0.001）. CONCLUSION： CRF was associated with elevated in-flammatory markers. The inflammation was observed at the severe stage of CRF and increases with progres-sion of renal failure.
文摘CeO2nanoparticles(NPs) were synthesized in alkaline medium via the homogeneous precipitation method and were subsequently calcined at 80 ℃/24 h(assigned as CeO2-80) and 500 ℃/2 h(assigned as CeO2-500). The as-prepared materials and the commercial ceria(assigned as CeO2-com) were characterized using TGA-MS, XRD, SEM-EDX, UV-vis DRS and IEP techniques. The photocatalytic performances of all obtained photocatalysts were assessed by the degradation of Congo red azo-dye(CR) under UVAlight irradiation at various environmental key factors(e.g., reaction time and calcination temperature).Results reveal that CeO2compounds crystalize with cubic phase, CeO2-500 exhibits smaller crystallite size(9 nm vs 117 nm) than that of bare CeO2-com. SEM analysis shows that the materials are sphericallike in shape NPs with strong assembly of CeO2NPs observed in the CeO2-500 NPs. EDX analysis confirms the stoichiometry of CeO2NPs. UV-vis DRS measurement reveals that, CeO2-500 NPs exhibits a red-shift of absorption band and a more narrow bandgap(2.6 eV vs 3.20 eV) than that of bare CeO2-com. On the contrary, Urbach energy of Eu is found to be increased from 0.12 eV(CeO2-com) to 0.17 eV(CeO2-500),highlighting an increase of crystalline size and internal microstrain in the CeO2-500 NPs sample. Zeta potential(IEP) of CeO2-500 NPs is found to be 7.2. UVA-light-responsive photocatalytic activity is observed with CeO2-500 NPs at a rate constant of 10×10-3min-1, which is four times higher than that of CeO2-com(Kapp=2.4×10-3min-1) for the degradation of CR. Pseudo-first-order kinetic model gives the best fit. On the basis of the energy band diagram positions, the enhanced photocatalytic performance of CeO2-500 nano-catalyst can be ascribed to O2-, ’OH and R’+as the primary oxidative species involved in the degradation of RC under UVA-light irradiation.
文摘The aim of this paper is to study the effect of agitator’s types on the turbulent flows in stirred tanks without and with baffles.The hydrodynamics behavior induced by four different agitator’s types:a Rushton turbine(RT),a circular blade turbine(CBT),a diverging triangular blade turbine(DTBT)and converging triangular blade turbine(CTBT)are numerically predicted by solving the Navier-Stokes equations and RNGκ–εturbulent model.The simulations are carried out using the Multi Reference Frame(MRF)approach.The numerical results showed good agreement with experiment.We find that the agitator CTBT gives an important profit on the power consumption per report/ratio the others and DTBT give a good reduction of the vortex size of the impeller angles.
文摘In the present paper, we examine the performance of an efficient type of wave-absorbing porous marine structure under the attack of regular oblique waves by using a Multi-Domain Boundary Element Method(MDBEM). The structure consists of two perforated vertical thin barriers creating what can be called a wave absorbing chamber system. The barriers are surface piercing, thereby eliminating wave overtopping. The problem of the interaction of obliquely incident linear waves upon a pair of perforated barriers is first formulated in the context of linear diffraction theory. The resulting boundary integral equation, which is matched with far-field solutions presented in terms of analytical series with unknown coefficients, as well as the appropriate boundary conditions at the free surface, seabed, and barriers, is then solved numerically using MDBEM. Dissipation of the wave energy due to the presence of the perforated barriers is represented by a simple yet effective relation in terms of the porosity parameter appropriate for thin perforated walls. The results are presented in terms of reflection and transmission coefficients. The effects of the incident wave angles, relative water depths, porosities, depths of the walls, and other major parameters of interest are explored.
基金supported by the Ministry of Higher Education and Scientific Research of People’s Democratic Republic of Algeria(Grant No.F02020110081)
文摘The chemical composition and antimicrobial potential of Cistus munbyi essential oil were studied for the first time. GC and GC–MS analysis revealed 48 compounds representing 96.98% of the oil. Terpinen-4-ol(23.75%), meta-Cymene(17.30%), and Sabinene(12.38%)were the major constituents. Antimicrobial activity was evaluated against nine pathogens using the disc diffusion and broth micro-dilution methods. Results show that C.munbyi essential oil possesses strong antimicrobial activity against all strains, regardless if Gram-positive or Gramnegative bacteria, or yeast, with MICs values not exceeding10(mg/ml). In addition to its efficacy, C. munbyi essential oil has an unusual antimicrobial potency which is attributed to its specific chemical composition. Thus, findings presented here suggest that endemic C. munbyi contains a very interesting essential oil that may be valuable in several areas.
基金the Yildiz Technical University Research Fund for financially supporting this work
文摘In this paper, reflection and transmission coefficients of regular waves from/through perforated thin walls are investigated. Small scale laboratory tests have been performed in a wave flume firstly with single perforated thin Plexiglas plates of various porosities. The plate is placed perpendicular to the flume with the height from the flume bottom to the position above water surface. With this thin wall in the flume wave overtopping is prohibited and incident waves are able to transmit. The porosities of the walls are achieved by perforating the plates with circular holes. Model settings with double perforated walls parallel to each other forming so called chamber system, have been also examined. Several parameters have been used for correlating the laboratory tests’ results. Experimental data are also compared with results from the numerical model by applying the multi-domain boundary element method （MDBEM） with linear wave theory. Wave energy dissipation due to the perforations of the thin wall has been represented by a simple yet effective porosity parameter in the model. The numerical model with the MDBEM has been further validated against the previously published data.
