The present study investigates the influence of friction time on the microstructural and mechanical properties of friction-welded joints for Ni-Cr-Mo steel(AISI 316)using the continuous drive friction welding(CDFW)pro...The present study investigates the influence of friction time on the microstructural and mechanical properties of friction-welded joints for Ni-Cr-Mo steel(AISI 316)using the continuous drive friction welding(CDFW)process.The research encompasses macro-and microstructural analysis,microhardness measurements along the axial direction and at the interface,tensile testing with effect-ive diameters of 4 mm and 6 mm,and compression testing at angles of 0°,45°,and 90°using specimens with dimensions of 4 mm in diameter and 6.5 mm in length.Additionally,impact tests were performed in symmetric and non-symmetric positions.The findings reveal that increasing friction time leads to the formation of a pronounced flash on the stationary side compared to the rotating side.Microstructural analysis shows fine grains in the highly plastically deformed zone(HPDZ)at the interface and elongated grains in the thermo-mechanically affected zone(TMAZ).At longer friction times(10 s),microhardness values reached approximately 300 HV0.1 at the welding interface,decreasing to 240-230 HV0.1 in adjacent regions.At shorter friction times(6.5 s),microhardness values were moderately lower,ranging from 260 HV0.1 to 240 HV0.1 at the interface and neighboring areas.For 6 mm diameter specimens,ulti-mate tensile strength(UTS)decreased with increasing friction time,reaching its lowest value at 8.5 s,while 4 mm diameter speci-mens exhibited a linear reduction in UTS with longer friction times.Compression tests demonstrated the highest yield strength at 0°,with values decreasing as friction time increased,indicating anisotropy in AISI 316 under friction time influence.Impact strength de-clined in non-symmetric positions compared to symmetric ones as friction time increased.展开更多
In this letter,we commented on the article by Wu et al.We examined the interactions between mesenteric adipose tissue,creeping fat,and gut microbiota in Crohn’s disease(CD),a condition marked by chronic gastrointesti...In this letter,we commented on the article by Wu et al.We examined the interactions between mesenteric adipose tissue,creeping fat,and gut microbiota in Crohn’s disease(CD),a condition marked by chronic gastrointestinal inflammation with a rising global incidence.The pathogenesis of CD involves complex genetic,environmental,and microbial factors.Dysbiosis,which is an imbalance in gut microbial communities,is frequently observed in CD patients,highlighting the pivotal role of the gut microbiota in disease progression and the inflammatory response.Recent studies have shown that mesenteric adipose tissue and creeping fat actively contribute to inflammation by producing proinflammatory cytokines.The relationship between creeping fat and altered microbiota can shift from a potentially protective role to one that encourages bacterial translocation,further complicating disease management.Recent research has suggested that fecal microbiota transplantation could help restore microbial balance,offering a promising therapeutic strategy to improve clinical disease response.展开更多
Intensive agricultural practices have undeniably reduced soil fertility and crop productivity.Furthermore,alkaline calcareous soils represent a significant challenge for agricultural production,particularly durum whea...Intensive agricultural practices have undeniably reduced soil fertility and crop productivity.Furthermore,alkaline calcareous soils represent a significant challenge for agricultural production,particularly durum wheat,which is vital for ensuring food security.It is therefore essential to explore new cereal management strategies to maintain food production and promote crop sustainability.The application of soil microorganisms,particularly plant growth–promoting rhizobacteria(PGPR),as inoculants to enhance crop production is a growing area of interest.This study investigates the effects of the rhizobacteria Paenibacillus polymyxa SGH1 and SGK2,applied both individually and in combination,on the growth and productivity of durum wheat in alkaline calcareous soil.We conducted field experiments over two growing seasons using a randomized complete block design with three blocks,considering four treatments:non-inoculated wheat grains(T0),inoculation with the P.polymyxa SGH1 strain(T1),inoculation with the P.polymyxa SGK2 strain(T2),and co-inoculation with both strains(T3).The results clearly showed that SGH1 and SGK2 inoculation improved the morphometric characteristics of wheat plants,with co-inoculation of both strains that induced more pronounced improvements compared to T0 in terms of collar diameter(+16.9%),tillers plant-1(+89.8%),and SA/RA ratio(+35.5%).Co-inoculation was also the most effective treatment for improving the wheat grain yield(+41.1%in season I and+16.6%in season Ⅱ).In addition,T3 significantly increased the grain starch content(+220%).T1 determined the highest grain protein content in both seasons(9.5%in season Ⅰand 9.66%DW in season Ⅱ).This study demonstrated that bacterial inoculation and co-inoculation strategies can significantly enhance wheat productivity and grain quality in alkaline calcareous soils while reducing at the same time the ecological footprint of agriculture.展开更多
The deformation behavior of the Mg-Y-Nd-Zr （WE54） alloy at temperatures between 25 and 400 ℃ was investigated by uniaxial and plans strain compression tests at strain rate values of 10-2 and 10^-4 s^-1. The results...The deformation behavior of the Mg-Y-Nd-Zr （WE54） alloy at temperatures between 25 and 400 ℃ was investigated by uniaxial and plans strain compression tests at strain rate values of 10-2 and 10^-4 s^-1. The results showed that the flow stress had a strong dependency on the loading condition. Yield stress and peak stress decreased with increasing deformation temperature and with decrease in the strain rate for both deformation types. The serration flow behavior was observed markedly at high temperatures and under a strain rate of 10^-4S^-1. The serration amplitude for samples deformed by plans strain compression was larger than that by uni- axial compression. Serrated flow was attributed to the interaction of dislocations with precipitates at 300 ℃ and to dynamic discon- tinuous recrystallization effects at 400 ℃.展开更多
The grain growth morphology,kinetics and texture change after uniaxial compression at 430 ℃ of an extruded AZ31 alloy were studied.The samples were loaded following two routes insuring two initial textures of the sam...The grain growth morphology,kinetics and texture change after uniaxial compression at 430 ℃ of an extruded AZ31 alloy were studied.The samples were loaded following two routes insuring two initial textures of the samples with compression direction parallel and normal to the extrusion direction.For both initial textures,a stable grain size is attained upon isothermal annealing and the grain growth kinetics can be described by:dn= dRn+kt with an n value of around 15.The annealing texture with grown grains is a retained hot deformation texture without emerging or strengthening other components.Abnormal grain growth is not observed for annealing time up to 10 000 h at 450℃.展开更多
A Pb-0.08Ca-2Sn alloy was subjected to rolling at room temperature to different final thicknesses.Annealing treatments at temperature ranging from 80 to 120 °C led to recrystallization of the samples as shown by ...A Pb-0.08Ca-2Sn alloy was subjected to rolling at room temperature to different final thicknesses.Annealing treatments at temperature ranging from 80 to 120 °C led to recrystallization of the samples as shown by resistivity and micro-hardness measurements.The deformation texture determined through X-ray diffraction is qualitatively the Brass type.The measured Lankford anisotropy parameter R and its evolution are close to the determined one using a self consistent approach.The R value evolution with angle to rolling direction shows the presence of planar anisotropy and poor drawability.The recrystallization in annealing at 80-120 °C is achieved within time period up to 3×104 s.The recrystallization texture is a retained deformation texture with an emerging Cube component.展开更多
AIM： To detect a possible association between the polymorphism of the （-670 A/G） Fas/Apol gene promoter and susceptibility to Crohn＇s disease （CD） and ulcerative colitis （UC） in the Tunisian population. METHOD...AIM： To detect a possible association between the polymorphism of the （-670 A/G） Fas/Apol gene promoter and susceptibility to Crohn＇s disease （CD） and ulcerative colitis （UC） in the Tunisian population. METHODS： The （-670 A/G） Fas polymorphism was analyzed in 105 patients with CD, 59 patients with UC, and 100 controls using the polymerase chain reaction restriction fragment length polymorphism method. RESULTS： Significantly lower frequencies of the Fas -670 A allele and A/A homozygous individuals were observed in CD and UC patients when compared with controls. Analysis of （-670 A/G） Fas polymorphism with respect to sex in CD and UC showed a significant difference in A/A genotypes between female patients and controls （P corrected = 0.004 ＂in CD patients＂ and P corrected = 0.02 ＂in UC patients＂, respectively）. Analysis also showed a statistically significant association between genotype AA of the （-670 A/G） polymorphism and the ileum localization of the lesions （P corrected = 0.048） and between genotype GG and the colon localization （P corrected = 0.009）. The analysis of IBD patients according to clinical behavior revealed no difference. CONCLUSION： Fas-670 polymorphism was associated with the development of CD and UC in the Tunisian population.展开更多
Dry reforming of methane by CO2 using nickel ferrite as precursor of catalysts was investigated.Nickel ferrite crystalline particles were prepared by coprecipitation of nitrates with NaOH or ammonia followed by calcin...Dry reforming of methane by CO2 using nickel ferrite as precursor of catalysts was investigated.Nickel ferrite crystalline particles were prepared by coprecipitation of nitrates with NaOH or ammonia followed by calcination,or by hydrothermal synthesis without calcination step.The textural and structural properties were determined by a number of analysis methods,including X-ray diffraction （XRD）,Raman spectroscopy and X-ray photoelectron spectroscopy （XPS）,among which X-ray diffraction （XRD） was at room and variable temperatures.All synthesized oxides showed the presence of micro or nanoparticles of NiFe2O4 inverse spinel,but Fe2O3 （hematite） was also present when ammonia was used for coprecipitation.The reducibility by hydrogen was studied by temperature-programmed reduction （TPR） and in situ XRD,which showed the influence of the preparation method.The surface area （BET）,particle size （Rietveld refinement）,as well as surface Ni/Fe atomic ratio （XPS） and the behavior upon reduction varied according to the synthesis method.The catalytic reactivity was investigated using isopropanol decomposition to determine the acid/base properties.The catalytic performance of methane reforming with CO2 was measured with and without the pre-treatment of catalysts under H2 in 650-800 C range.The catalytic conversions of methane and CO2 were quite low but they increased when the catalysts were pre-reduced.A significant contribution of reverse water gas shift reaction accounted for the low values of H2 /CO ratio.No coking was observed as shown by the reoxidation step performed after the catalytic reactions.The possible formation of nickel-iron alloy observed during the study of reducibility by hydrogen was invoked to account for the catalytic behavior.展开更多
For joining high Cr,Ni and Mo austenitic stainless steel(AISI 316)by direct drive friction welding(DDFW),with friction weld-ing conditions:rotation speed of 3000 r/min,friction time of 10 s,friction pressure of 130 MP...For joining high Cr,Ni and Mo austenitic stainless steel(AISI 316)by direct drive friction welding(DDFW),with friction weld-ing conditions:rotation speed of 3000 r/min,friction time of 10 s,friction pressure of 130 MPa,forge time of 5 s and forge pressure of 260 MPa.The results of microstructure showed that the temperature at the interface reached 819℃while forge applied between 357-237℃,which subdivided welded joint into four distinct regions of highly plastically deformed zone(HPDZ),thermo-mechanically affected zone(TMAZ),heat affected zone(HAZ)and the base metal,with grain size about 10µm,100µm,90µm and 30µm respectively.These re-gions were created due to dynamic recrystallization(DRX)at the interface and thermo-mechanical deformation with heat diffusion in the neighboring regions.Whereas,high level of microhardness about 300 HV0.1 and hardness roughly 240 Hv10 at the interface due to HPDZ creation while low level of 240 HV0.1 for microhardness and moderately of 205 HV10 for hardness in neighboring regions.展开更多
The influence of interlayer anions such as NO3-, 5042- and Cl- on Mg-AI hydrotalcites for Cr（Vl） removal from aqueous solution was studied. The structure of the prepared LDHs was characterized by XRD, SEM, FTIR, TGA...The influence of interlayer anions such as NO3-, 5042- and Cl- on Mg-AI hydrotalcites for Cr（Vl） removal from aqueous solution was studied. The structure of the prepared LDHs was characterized by XRD, SEM, FTIR, TGA, BET surface area and pHzpc. The sorbent ability and sorption mechanisms were also investigated. The LDHs exhibit high removal for Cr（VI）, and the sorbed amount depends on the nature of interlayer anion, which decreased in the following order： NO3- 〉 Cl 〉 SO42-, Nitrate-containing LDH reached a Cr（VI） sorption equilibrium within only 30 min. The effects of operating conditions, including initial concentration, solution pH, agitation time and sorbent amount have been studied in batch mode. The optimum conditions were observed at an initial concen- tration of 100 mg. L- 1, pH = 6, agitation time of 60 min and a sorbent dose of 2 g.L- 1. The equilibrium data were fitted to the Langmuir, Freundlich and Dubinin-Radushkevich isotherm models. The Langmuir model was found to sufficiently describe the sorption process, offering a maximum sorption capacity of 71.91 mg-g 1. The sorp- tion kinetic follows pseudo-second-order reaction with high accuracy. Thermodynamic parameters suggested that the sorption process is spontaneous and endothermic in nature.展开更多
Nuclear facility aging is one of the biggest problems encountered in nuclear engineering. Radiation damage is among one of the aging causes. This kind of damage is an important factor of mechanical properties deterior...Nuclear facility aging is one of the biggest problems encountered in nuclear engineering. Radiation damage is among one of the aging causes. This kind of damage is an important factor of mechanical properties deterioration. The interest of this study is on the Es-Salam research reactor aluminum vessel aging due to neutron radiation. Monte Carlo(MC) simulations were performed by MCNP6 and SRIM codes to estimate the defects created by neutrons in the vessel. MC simulations by MCNP6 have been performed to determine the distribution of neutron fluence and primary knock-on atom(PKA) creation. Considering our boundary conditions of the calculations, the helium and hydrogen gas production in the model at a normalized total neutron flux of 6.62×10^(12) n/cm^2 s were determined to be 2.86 × 10~8 and 1.33 × 10~9 atoms/cm^3 s,respectively. The SRIM code was used for the simulation of defects creation(vacancies, voids) in the aluminum alloy of the Es-Salam vessel(EsAl) by helium and hydrogen with an approximate energy of 11 MeV each.The coupling between the two codes is based upon postprocessing of the particle track(PTRAC) output file generated by the MCNP6. A small program based on the Mat Lab language is performed to condition the output file MCNP6 in the format of a SRIM input file. The concentration of silicon was determined for the vessel by the calculation of the total rate of ^(27)Al(n,γ)^(28)Si reaction. The DPA(displacement per atom) was calculated in SRIM according to R.E. Stoller recommendations; the calculated value is 0.02 at a fast neutron fluence 1.89 × 10^(19) n/cm^2.RCC-MRx standard for 6061-T6 aluminum was used for the simulation of the evolution of mechanical properties for high fluence. The calculated values of nuclear parameters and DPA obtained were in agreement with the experimental results from the Oak Ridge High Flux Isotope Reactor(HFIR) reported by Farrell and coworkers.展开更多
Cellulose triacetate membranes doped with organo-phosphoric carriers (2-ethylhexyl) phosphoric acid noted (D2EHPA) or trioctyl phosphine oxide noted (TOPO) as fixed carriers and 2-nitro phenyl octyl ether noted (NPOE)...Cellulose triacetate membranes doped with organo-phosphoric carriers (2-ethylhexyl) phosphoric acid noted (D2EHPA) or trioctyl phosphine oxide noted (TOPO) as fixed carriers and 2-nitro phenyl octyl ether noted (NPOE) or tris ethylhexyl phosphate noted (TEHP) as a plasticizers have been prepared and applied for investigation to the facilitated transport of Pb(II) and Cd(II) ions from aqueous nitrate source phase. The membranes Polymer-Plasticizer- Carrier were characterised using chemical techniques as well as Fourier Transform Infra-Red (FTIR), X-ray Diffraction and Scanning electron microscopy (SEM). A study of the transport across a polymer inclusion membrane has shown that the lead or cadmium transport efficiency was increased using D2EHPA as carrier at pH 1-2.展开更多
In order to determine the response to high-frequency oscillatory ventilation (HFOV), used as an “early rescue”therapy, in a cohort of paediatric patients with acute respiratory distress syndrome (ARDS), a prospectiv...In order to determine the response to high-frequency oscillatory ventilation (HFOV), used as an “early rescue”therapy, in a cohort of paediatric patients with acute respiratory distress syndrome (ARDS), a prospective clinical study was performed in a tertiary care paediatric intensive care unit. Ten consecutive patients, aged 12 days to 5 years with ARDS and hypoxaemic respiratory failure on conventional ventilation (CV), using a lung protective strategy, were managed with HFOV early in the course of the disease process (median length of CV 4 h). Arterial blood gases, oxygenation index (OI), alveolar-arterial oxygen difference (P(A-a)O2) and PaO2/FIO2 ratio were prospectively recorded prior to HFOV (0 h) and at predetermined intervals throughout the course of the HFOV protocol. There was a significant improvement in PaCO2 4 h after institution of HFOV (P =0.012). A significant and sustained increase (P < 0.001) in PaO2/FIO2 ratio and a significant and sustained decrease (P < 0.001) in OI and P(A-a)O2 were demonstrated during the HFOV trial. These improvements were achieved 4 h after initiating HFOV (P < 0.05). Eight patients survived. There were no deaths from respiratory failure. Conclusion: In paediatric patients with acute respiratory distress syndrome and hypoxaemic respiratory failure on conventional ventilation, using a lung protective strategy, high-frequency oscillatory ventilation used as an “early rescue”therapy, improves gas exchange in a rapid and sustained fashion and provides a good outcome. Use of this therapy should probably be considered early in the course of the disease process.展开更多
For a lot of applications in the mechanical industry,both attractive and mechanical properties of materials and wear resistance are required.Usually such a combination is achieved only by performing surface treatments...For a lot of applications in the mechanical industry,both attractive and mechanical properties of materials and wear resistance are required.Usually such a combination is achieved only by performing surface treatments.The aim of this investigation is the consolidation of 12% Mn steel surface by treatment of impacts.We show by optical and scanning electron microscopy,X ray diffraction,X ray spectrometry analysis and also by the realization of micro hardness,the effect of this kind of treatment on the mechanical and structural stability of the surface zone.Among of many obtained results,we distinguish the clear surface consolidation induced by a modification of surface zone crystalline structure.The mechanical deformation causes the transformation from an austenitic structure to the martensitic structure.展开更多
Over the last ten years, several comprehensive reviews of iron thermodynamics data were published. This work aims to： （i） propose a consistent set of Gibbs free energies （AfG~） of ferrous hydroxide, Fe（OH）2.cr ...Over the last ten years, several comprehensive reviews of iron thermodynamics data were published. This work aims to： （i） propose a consistent set of Gibbs free energies （AfG~） of ferrous hydroxide, Fe（OH）2.cr and of synthetic Green rusts I and II; （ii） check the consistency of the data of these isostructural compounds by means of a correlation obtained with electronegativities of the anions. Experimental data are concentrations in aqueous solutions and pH, and must be processed to obtain ionic activity products （lAP）. The model of Specific Interaction Theory （SIT） was used here. Firstly, some complexes whose existences are doubtful were removed from the SIT database. The new modified database is given here. Secondly, experimental data were processed. Thirdly, the following relation of regression between Gibbs free energies of formation of Green rusts and normalized Allred-Rochow electronegativities of anions was obtained as： △fG0 = -488.354 -353.11 （x/n）, r = -0.994. This relation was then used to assess the Gibbs free energy of formation for GR1-OH, simply written as Fe3（OH）7.展开更多
Volume negative ion production relies on a magnetic filter(MF),where the plasma downstream of the MF is characterized by a strip-like pattern that consists of a bright and dense plasma region.In this work,we study,in ...Volume negative ion production relies on a magnetic filter(MF),where the plasma downstream of the MF is characterized by a strip-like pattern that consists of a bright and dense plasma region.In this work,we study,in a radio-frequency plasma source,the effects of operating pressure on this strip.This investigation,conducted using a Langmuir probe,shows that the plasma uniformity might be controlled through the gas pressure.Moreover,the operating pressure determines on which hemi-cylinder(side of magnetic field lines)the strip forms.This side inversion of the high-density plasma hemi-cylinder is due to an inversion of an ambipolar electric field that changes the E?×?B drift direction.展开更多
Background: While causing a financial and economic loss in many countries in a few months, COVID 19 was of great impact on public health. The Iraqi government took several measures since the first Iraqi case was disco...Background: While causing a financial and economic loss in many countries in a few months, COVID 19 was of great impact on public health. The Iraqi government took several measures since the first Iraqi case was discovered in February 2020. One of the fundamental measures to control this pandemic is social isolation, which depends greatly on people’s awareness to decrease the incidence of COVID-19. Objectives: To study the COVID-19-effect on dentists’ social life and their future plan, and to find the relation between that effect and some dentists’ demographic variables. Methods: A cross-sectional study was conducted from 2nd January to 7th May 2021, by an electronic version of the questionnaire through Google form. With facilitating orders delivered to all the specialist dental centers for adults of Al-Resafa health directorate;any dentists working in specialist dental centers for adults of Al-Resafa health directorate, and accept to participate in this study. Results: A total of 10 specialist dental centers for adults of the Al-Resafa health directorate represent 566/628 dentists enrolled in this study with a response rate of 88.99%. Most of them aged less than 30 years old (62.2%), female (60.6%), married status (50.4%), had 1 - 3 children (71.91%), Rotator (51.1%), with less than five years of experience (61.3%). Conclusion: COVID-19 affected so many aspects of health workers’ lives including dentists. About two-thirds of dentists had negative feelings, of which almost all had anxiety. Younger ages, females, married and having children are factors that contribute to the affection of dental social lives more than other categories.展开更多
OBJECTIVE:To evaluate the antidiarrheal effect of jujube honey on experimentally castor oil-induced diarrhea in mice by using different testing models(diarrhea,enteropooling and gastrointestinal motility).METHODS:The ...OBJECTIVE:To evaluate the antidiarrheal effect of jujube honey on experimentally castor oil-induced diarrhea in mice by using different testing models(diarrhea,enteropooling and gastrointestinal motility).METHODS:The mice intragastric administration castor oil was post-treated after 30 min with jujube honey,diluted jujube honey and loperamide or vehicles in different experimental groups.The onset and number of wet defecation on the absorbent paper was recorded for each animal for 4 h.Plasma was examined for C-reactive protein(CRP)and nitric oxide(NO)for clinical inflammation evaluation.The oxidative stress was investigated by superoxide dismutase(SOD)and catalase levels.RESULTS:The diluted jujube honey exhibited an important antidiarrheal activity manifested by significant delay in onset of diarrhea(P<0.05),loss in number of wet stools(P<0.001),total number of stools(P<0.001)and total stool weight of fecal output(P<0.001)in 4 h in castor oil-induced diarrheal groups.The inhibition of intestinal transit of charcoal meal(P<0.01)is a most likely mechanism that may account for antidiarrheal effect of jujube honey.It also significantly increased SOD and catalase levels(P<0.001)and significantly decreased CRP and NO in plasma diarrheic mice(P<0.01).CONCLUSION:The results of this research reveal that the jujube honey contains pharmacologically active compounds with antidiarrheal properties.However,diluted honey is more effective in the treatment of diarrhea and imbalance of intestinal motility.In conclusion,these findings illustrated the antidiarrheal activity effect of jujube honey and which has the strongest evidence supporting its use in the treatment of diarrhea in traditional medicine.展开更多
Adsorption kinetics in multi-component systems has been a subject of intensive research because it is of both theoretical and practical importance. In this paper, raw date palm seeds （RDPS） were investigated to asse...Adsorption kinetics in multi-component systems has been a subject of intensive research because it is of both theoretical and practical importance. In this paper, raw date palm seeds （RDPS） were investigated to assess the possible use of this raw material as an effective adsorbent for the removal of sulfate from aqueous solution. The influence of various parameters such as sulfate initial concentration, pH, adsorbent dose and stirring time has been studied for the adsorption of sulfate in batch mode. Effects of foreign anions on the adsorption of sulfate onto RDPS have been also investigated. The pseudo-second-order, Elovich and intraparticle diffusion kinetic models have been developed to predict the rate constants of adsorption and equilibrium capacities. The maximum adsorption capacity of sulfate （qe ≈3.2 mg/g） onto RDPS was reached for the initial sulfate concentration = 100 mg/L, pH - 3.5, adsorbent dose = 10 g/L and for a stirring intensity = 200 rpm at 25 ± 2 ℃. The results showed that the adsorption of sulfate onto this raw materials followed pseudo-second-order rate kinetic predicting a chemisorption process.展开更多
Because of socio-economic importance of date palm in North Africa, the scientific community has always followed the progression of parasitic disease that affects it. The study was performed on population of thirty pal...Because of socio-economic importance of date palm in North Africa, the scientific community has always followed the progression of parasitic disease that affects it. The study was performed on population of thirty palm trees belonging to three cultivars of the oases of south-west Algeria TOUAT Gourara. The analytical protocol consists of a hot hydrochloric acid hydrolysis of I g of leaf material dried and ground. Structural analysis of compounds present in extracts was conducted by chromatographic and spectrophotometric techniques. Through the analysis of all HPLC profiles of phenolic acids, we have established three chemotypes： resistant with the highest heights, sensitive, with the lowest height, finally low sensitivity or tolerant with intermediate heights. The increased synthesis of C-glycoflavones, within diseased palms, can be seen as the first sign of plant response to fungal attack, or even as a defense mechanism so these flavonoids correspond to ＂pre-inhibitines＂. It has not been found qualitative differences between different cultivars studied. The merits of our work show a negative correlation between flavonoid content and the level of lignification in the date palm, suggests that the process of lignification is more rapid in resistant cultivars. We can say that there is a constitutive resistance.展开更多
文摘The present study investigates the influence of friction time on the microstructural and mechanical properties of friction-welded joints for Ni-Cr-Mo steel(AISI 316)using the continuous drive friction welding(CDFW)process.The research encompasses macro-and microstructural analysis,microhardness measurements along the axial direction and at the interface,tensile testing with effect-ive diameters of 4 mm and 6 mm,and compression testing at angles of 0°,45°,and 90°using specimens with dimensions of 4 mm in diameter and 6.5 mm in length.Additionally,impact tests were performed in symmetric and non-symmetric positions.The findings reveal that increasing friction time leads to the formation of a pronounced flash on the stationary side compared to the rotating side.Microstructural analysis shows fine grains in the highly plastically deformed zone(HPDZ)at the interface and elongated grains in the thermo-mechanically affected zone(TMAZ).At longer friction times(10 s),microhardness values reached approximately 300 HV0.1 at the welding interface,decreasing to 240-230 HV0.1 in adjacent regions.At shorter friction times(6.5 s),microhardness values were moderately lower,ranging from 260 HV0.1 to 240 HV0.1 at the interface and neighboring areas.For 6 mm diameter specimens,ulti-mate tensile strength(UTS)decreased with increasing friction time,reaching its lowest value at 8.5 s,while 4 mm diameter speci-mens exhibited a linear reduction in UTS with longer friction times.Compression tests demonstrated the highest yield strength at 0°,with values decreasing as friction time increased,indicating anisotropy in AISI 316 under friction time influence.Impact strength de-clined in non-symmetric positions compared to symmetric ones as friction time increased.
文摘In this letter,we commented on the article by Wu et al.We examined the interactions between mesenteric adipose tissue,creeping fat,and gut microbiota in Crohn’s disease(CD),a condition marked by chronic gastrointestinal inflammation with a rising global incidence.The pathogenesis of CD involves complex genetic,environmental,and microbial factors.Dysbiosis,which is an imbalance in gut microbial communities,is frequently observed in CD patients,highlighting the pivotal role of the gut microbiota in disease progression and the inflammatory response.Recent studies have shown that mesenteric adipose tissue and creeping fat actively contribute to inflammation by producing proinflammatory cytokines.The relationship between creeping fat and altered microbiota can shift from a potentially protective role to one that encourages bacterial translocation,further complicating disease management.Recent research has suggested that fecal microbiota transplantation could help restore microbial balance,offering a promising therapeutic strategy to improve clinical disease response.
基金QK22020008(National Agency of Agricultural Research of the Czech Republic)TQ03000234(Technological Agency of the Czech Republic)MZE-RO0123(Ministry of Agriculture,CR).
文摘Intensive agricultural practices have undeniably reduced soil fertility and crop productivity.Furthermore,alkaline calcareous soils represent a significant challenge for agricultural production,particularly durum wheat,which is vital for ensuring food security.It is therefore essential to explore new cereal management strategies to maintain food production and promote crop sustainability.The application of soil microorganisms,particularly plant growth–promoting rhizobacteria(PGPR),as inoculants to enhance crop production is a growing area of interest.This study investigates the effects of the rhizobacteria Paenibacillus polymyxa SGH1 and SGK2,applied both individually and in combination,on the growth and productivity of durum wheat in alkaline calcareous soil.We conducted field experiments over two growing seasons using a randomized complete block design with three blocks,considering four treatments:non-inoculated wheat grains(T0),inoculation with the P.polymyxa SGH1 strain(T1),inoculation with the P.polymyxa SGK2 strain(T2),and co-inoculation with both strains(T3).The results clearly showed that SGH1 and SGK2 inoculation improved the morphometric characteristics of wheat plants,with co-inoculation of both strains that induced more pronounced improvements compared to T0 in terms of collar diameter(+16.9%),tillers plant-1(+89.8%),and SA/RA ratio(+35.5%).Co-inoculation was also the most effective treatment for improving the wheat grain yield(+41.1%in season I and+16.6%in season Ⅱ).In addition,T3 significantly increased the grain starch content(+220%).T1 determined the highest grain protein content in both seasons(9.5%in season Ⅰand 9.66%DW in season Ⅱ).This study demonstrated that bacterial inoculation and co-inoculation strategies can significantly enhance wheat productivity and grain quality in alkaline calcareous soils while reducing at the same time the ecological footprint of agriculture.
文摘The deformation behavior of the Mg-Y-Nd-Zr （WE54） alloy at temperatures between 25 and 400 ℃ was investigated by uniaxial and plans strain compression tests at strain rate values of 10-2 and 10^-4 s^-1. The results showed that the flow stress had a strong dependency on the loading condition. Yield stress and peak stress decreased with increasing deformation temperature and with decrease in the strain rate for both deformation types. The serration flow behavior was observed markedly at high temperatures and under a strain rate of 10^-4S^-1. The serration amplitude for samples deformed by plans strain compression was larger than that by uni- axial compression. Serrated flow was attributed to the interaction of dislocations with precipitates at 300 ℃ and to dynamic discon- tinuous recrystallization effects at 400 ℃.
文摘The grain growth morphology,kinetics and texture change after uniaxial compression at 430 ℃ of an extruded AZ31 alloy were studied.The samples were loaded following two routes insuring two initial textures of the samples with compression direction parallel and normal to the extrusion direction.For both initial textures,a stable grain size is attained upon isothermal annealing and the grain growth kinetics can be described by:dn= dRn+kt with an n value of around 15.The annealing texture with grown grains is a retained hot deformation texture without emerging or strengthening other components.Abnormal grain growth is not observed for annealing time up to 10 000 h at 450℃.
文摘A Pb-0.08Ca-2Sn alloy was subjected to rolling at room temperature to different final thicknesses.Annealing treatments at temperature ranging from 80 to 120 °C led to recrystallization of the samples as shown by resistivity and micro-hardness measurements.The deformation texture determined through X-ray diffraction is qualitatively the Brass type.The measured Lankford anisotropy parameter R and its evolution are close to the determined one using a self consistent approach.The R value evolution with angle to rolling direction shows the presence of planar anisotropy and poor drawability.The recrystallization in annealing at 80-120 °C is achieved within time period up to 3×104 s.The recrystallization texture is a retained deformation texture with an emerging Cube component.
基金Supported by Laboratory of Immunology, EPS Charles Nicolle,Tunis, Tunisia
文摘AIM： To detect a possible association between the polymorphism of the （-670 A/G） Fas/Apol gene promoter and susceptibility to Crohn＇s disease （CD） and ulcerative colitis （UC） in the Tunisian population. METHODS： The （-670 A/G） Fas polymorphism was analyzed in 105 patients with CD, 59 patients with UC, and 100 controls using the polymerase chain reaction restriction fragment length polymorphism method. RESULTS： Significantly lower frequencies of the Fas -670 A allele and A/A homozygous individuals were observed in CD and UC patients when compared with controls. Analysis of （-670 A/G） Fas polymorphism with respect to sex in CD and UC showed a significant difference in A/A genotypes between female patients and controls （P corrected = 0.004 ＂in CD patients＂ and P corrected = 0.02 ＂in UC patients＂, respectively）. Analysis also showed a statistically significant association between genotype AA of the （-670 A/G） polymorphism and the ileum localization of the lesions （P corrected = 0.048） and between genotype GG and the colon localization （P corrected = 0.009）. The analysis of IBD patients according to clinical behavior revealed no difference. CONCLUSION： Fas-670 polymorphism was associated with the development of CD and UC in the Tunisian population.
文摘Dry reforming of methane by CO2 using nickel ferrite as precursor of catalysts was investigated.Nickel ferrite crystalline particles were prepared by coprecipitation of nitrates with NaOH or ammonia followed by calcination,or by hydrothermal synthesis without calcination step.The textural and structural properties were determined by a number of analysis methods,including X-ray diffraction （XRD）,Raman spectroscopy and X-ray photoelectron spectroscopy （XPS）,among which X-ray diffraction （XRD） was at room and variable temperatures.All synthesized oxides showed the presence of micro or nanoparticles of NiFe2O4 inverse spinel,but Fe2O3 （hematite） was also present when ammonia was used for coprecipitation.The reducibility by hydrogen was studied by temperature-programmed reduction （TPR） and in situ XRD,which showed the influence of the preparation method.The surface area （BET）,particle size （Rietveld refinement）,as well as surface Ni/Fe atomic ratio （XPS） and the behavior upon reduction varied according to the synthesis method.The catalytic reactivity was investigated using isopropanol decomposition to determine the acid/base properties.The catalytic performance of methane reforming with CO2 was measured with and without the pre-treatment of catalysts under H2 in 650-800 C range.The catalytic conversions of methane and CO2 were quite low but they increased when the catalysts were pre-reduced.A significant contribution of reverse water gas shift reaction accounted for the low values of H2 /CO ratio.No coking was observed as shown by the reoxidation step performed after the catalytic reactions.The possible formation of nickel-iron alloy observed during the study of reducibility by hydrogen was invoked to account for the catalytic behavior.
文摘For joining high Cr,Ni and Mo austenitic stainless steel(AISI 316)by direct drive friction welding(DDFW),with friction weld-ing conditions:rotation speed of 3000 r/min,friction time of 10 s,friction pressure of 130 MPa,forge time of 5 s and forge pressure of 260 MPa.The results of microstructure showed that the temperature at the interface reached 819℃while forge applied between 357-237℃,which subdivided welded joint into four distinct regions of highly plastically deformed zone(HPDZ),thermo-mechanically affected zone(TMAZ),heat affected zone(HAZ)and the base metal,with grain size about 10µm,100µm,90µm and 30µm respectively.These re-gions were created due to dynamic recrystallization(DRX)at the interface and thermo-mechanical deformation with heat diffusion in the neighboring regions.Whereas,high level of microhardness about 300 HV0.1 and hardness roughly 240 Hv10 at the interface due to HPDZ creation while low level of 240 HV0.1 for microhardness and moderately of 205 HV10 for hardness in neighboring regions.
基金financially supported by both the department of Process Engineering and Chemistry of USTHB(Algiers)
文摘The influence of interlayer anions such as NO3-, 5042- and Cl- on Mg-AI hydrotalcites for Cr（Vl） removal from aqueous solution was studied. The structure of the prepared LDHs was characterized by XRD, SEM, FTIR, TGA, BET surface area and pHzpc. The sorbent ability and sorption mechanisms were also investigated. The LDHs exhibit high removal for Cr（VI）, and the sorbed amount depends on the nature of interlayer anion, which decreased in the following order： NO3- 〉 Cl 〉 SO42-, Nitrate-containing LDH reached a Cr（VI） sorption equilibrium within only 30 min. The effects of operating conditions, including initial concentration, solution pH, agitation time and sorbent amount have been studied in batch mode. The optimum conditions were observed at an initial concen- tration of 100 mg. L- 1, pH = 6, agitation time of 60 min and a sorbent dose of 2 g.L- 1. The equilibrium data were fitted to the Langmuir, Freundlich and Dubinin-Radushkevich isotherm models. The Langmuir model was found to sufficiently describe the sorption process, offering a maximum sorption capacity of 71.91 mg-g 1. The sorp- tion kinetic follows pseudo-second-order reaction with high accuracy. Thermodynamic parameters suggested that the sorption process is spontaneous and endothermic in nature.
文摘Nuclear facility aging is one of the biggest problems encountered in nuclear engineering. Radiation damage is among one of the aging causes. This kind of damage is an important factor of mechanical properties deterioration. The interest of this study is on the Es-Salam research reactor aluminum vessel aging due to neutron radiation. Monte Carlo(MC) simulations were performed by MCNP6 and SRIM codes to estimate the defects created by neutrons in the vessel. MC simulations by MCNP6 have been performed to determine the distribution of neutron fluence and primary knock-on atom(PKA) creation. Considering our boundary conditions of the calculations, the helium and hydrogen gas production in the model at a normalized total neutron flux of 6.62×10^(12) n/cm^2 s were determined to be 2.86 × 10~8 and 1.33 × 10~9 atoms/cm^3 s,respectively. The SRIM code was used for the simulation of defects creation(vacancies, voids) in the aluminum alloy of the Es-Salam vessel(EsAl) by helium and hydrogen with an approximate energy of 11 MeV each.The coupling between the two codes is based upon postprocessing of the particle track(PTRAC) output file generated by the MCNP6. A small program based on the Mat Lab language is performed to condition the output file MCNP6 in the format of a SRIM input file. The concentration of silicon was determined for the vessel by the calculation of the total rate of ^(27)Al(n,γ)^(28)Si reaction. The DPA(displacement per atom) was calculated in SRIM according to R.E. Stoller recommendations; the calculated value is 0.02 at a fast neutron fluence 1.89 × 10^(19) n/cm^2.RCC-MRx standard for 6061-T6 aluminum was used for the simulation of the evolution of mechanical properties for high fluence. The calculated values of nuclear parameters and DPA obtained were in agreement with the experimental results from the Oak Ridge High Flux Isotope Reactor(HFIR) reported by Farrell and coworkers.
文摘Cellulose triacetate membranes doped with organo-phosphoric carriers (2-ethylhexyl) phosphoric acid noted (D2EHPA) or trioctyl phosphine oxide noted (TOPO) as fixed carriers and 2-nitro phenyl octyl ether noted (NPOE) or tris ethylhexyl phosphate noted (TEHP) as a plasticizers have been prepared and applied for investigation to the facilitated transport of Pb(II) and Cd(II) ions from aqueous nitrate source phase. The membranes Polymer-Plasticizer- Carrier were characterised using chemical techniques as well as Fourier Transform Infra-Red (FTIR), X-ray Diffraction and Scanning electron microscopy (SEM). A study of the transport across a polymer inclusion membrane has shown that the lead or cadmium transport efficiency was increased using D2EHPA as carrier at pH 1-2.
文摘In order to determine the response to high-frequency oscillatory ventilation (HFOV), used as an “early rescue”therapy, in a cohort of paediatric patients with acute respiratory distress syndrome (ARDS), a prospective clinical study was performed in a tertiary care paediatric intensive care unit. Ten consecutive patients, aged 12 days to 5 years with ARDS and hypoxaemic respiratory failure on conventional ventilation (CV), using a lung protective strategy, were managed with HFOV early in the course of the disease process (median length of CV 4 h). Arterial blood gases, oxygenation index (OI), alveolar-arterial oxygen difference (P(A-a)O2) and PaO2/FIO2 ratio were prospectively recorded prior to HFOV (0 h) and at predetermined intervals throughout the course of the HFOV protocol. There was a significant improvement in PaCO2 4 h after institution of HFOV (P =0.012). A significant and sustained increase (P < 0.001) in PaO2/FIO2 ratio and a significant and sustained decrease (P < 0.001) in OI and P(A-a)O2 were demonstrated during the HFOV trial. These improvements were achieved 4 h after initiating HFOV (P < 0.05). Eight patients survived. There were no deaths from respiratory failure. Conclusion: In paediatric patients with acute respiratory distress syndrome and hypoxaemic respiratory failure on conventional ventilation, using a lung protective strategy, high-frequency oscillatory ventilation used as an “early rescue”therapy, improves gas exchange in a rapid and sustained fashion and provides a good outcome. Use of this therapy should probably be considered early in the course of the disease process.
文摘For a lot of applications in the mechanical industry,both attractive and mechanical properties of materials and wear resistance are required.Usually such a combination is achieved only by performing surface treatments.The aim of this investigation is the consolidation of 12% Mn steel surface by treatment of impacts.We show by optical and scanning electron microscopy,X ray diffraction,X ray spectrometry analysis and also by the realization of micro hardness,the effect of this kind of treatment on the mechanical and structural stability of the surface zone.Among of many obtained results,we distinguish the clear surface consolidation induced by a modification of surface zone crystalline structure.The mechanical deformation causes the transformation from an austenitic structure to the martensitic structure.
文摘Over the last ten years, several comprehensive reviews of iron thermodynamics data were published. This work aims to： （i） propose a consistent set of Gibbs free energies （AfG~） of ferrous hydroxide, Fe（OH）2.cr and of synthetic Green rusts I and II; （ii） check the consistency of the data of these isostructural compounds by means of a correlation obtained with electronegativities of the anions. Experimental data are concentrations in aqueous solutions and pH, and must be processed to obtain ionic activity products （lAP）. The model of Specific Interaction Theory （SIT） was used here. Firstly, some complexes whose existences are doubtful were removed from the SIT database. The new modified database is given here. Secondly, experimental data were processed. Thirdly, the following relation of regression between Gibbs free energies of formation of Green rusts and normalized Allred-Rochow electronegativities of anions was obtained as： △fG0 = -488.354 -353.11 （x/n）, r = -0.994. This relation was then used to assess the Gibbs free energy of formation for GR1-OH, simply written as Fe3（OH）7.
文摘Volume negative ion production relies on a magnetic filter(MF),where the plasma downstream of the MF is characterized by a strip-like pattern that consists of a bright and dense plasma region.In this work,we study,in a radio-frequency plasma source,the effects of operating pressure on this strip.This investigation,conducted using a Langmuir probe,shows that the plasma uniformity might be controlled through the gas pressure.Moreover,the operating pressure determines on which hemi-cylinder(side of magnetic field lines)the strip forms.This side inversion of the high-density plasma hemi-cylinder is due to an inversion of an ambipolar electric field that changes the E?×?B drift direction.
文摘Background: While causing a financial and economic loss in many countries in a few months, COVID 19 was of great impact on public health. The Iraqi government took several measures since the first Iraqi case was discovered in February 2020. One of the fundamental measures to control this pandemic is social isolation, which depends greatly on people’s awareness to decrease the incidence of COVID-19. Objectives: To study the COVID-19-effect on dentists’ social life and their future plan, and to find the relation between that effect and some dentists’ demographic variables. Methods: A cross-sectional study was conducted from 2nd January to 7th May 2021, by an electronic version of the questionnaire through Google form. With facilitating orders delivered to all the specialist dental centers for adults of Al-Resafa health directorate;any dentists working in specialist dental centers for adults of Al-Resafa health directorate, and accept to participate in this study. Results: A total of 10 specialist dental centers for adults of the Al-Resafa health directorate represent 566/628 dentists enrolled in this study with a response rate of 88.99%. Most of them aged less than 30 years old (62.2%), female (60.6%), married status (50.4%), had 1 - 3 children (71.91%), Rotator (51.1%), with less than five years of experience (61.3%). Conclusion: COVID-19 affected so many aspects of health workers’ lives including dentists. About two-thirds of dentists had negative feelings, of which almost all had anxiety. Younger ages, females, married and having children are factors that contribute to the affection of dental social lives more than other categories.
文摘OBJECTIVE:To evaluate the antidiarrheal effect of jujube honey on experimentally castor oil-induced diarrhea in mice by using different testing models(diarrhea,enteropooling and gastrointestinal motility).METHODS:The mice intragastric administration castor oil was post-treated after 30 min with jujube honey,diluted jujube honey and loperamide or vehicles in different experimental groups.The onset and number of wet defecation on the absorbent paper was recorded for each animal for 4 h.Plasma was examined for C-reactive protein(CRP)and nitric oxide(NO)for clinical inflammation evaluation.The oxidative stress was investigated by superoxide dismutase(SOD)and catalase levels.RESULTS:The diluted jujube honey exhibited an important antidiarrheal activity manifested by significant delay in onset of diarrhea(P<0.05),loss in number of wet stools(P<0.001),total number of stools(P<0.001)and total stool weight of fecal output(P<0.001)in 4 h in castor oil-induced diarrheal groups.The inhibition of intestinal transit of charcoal meal(P<0.01)is a most likely mechanism that may account for antidiarrheal effect of jujube honey.It also significantly increased SOD and catalase levels(P<0.001)and significantly decreased CRP and NO in plasma diarrheic mice(P<0.01).CONCLUSION:The results of this research reveal that the jujube honey contains pharmacologically active compounds with antidiarrheal properties.However,diluted honey is more effective in the treatment of diarrhea and imbalance of intestinal motility.In conclusion,these findings illustrated the antidiarrheal activity effect of jujube honey and which has the strongest evidence supporting its use in the treatment of diarrhea in traditional medicine.
文摘Adsorption kinetics in multi-component systems has been a subject of intensive research because it is of both theoretical and practical importance. In this paper, raw date palm seeds （RDPS） were investigated to assess the possible use of this raw material as an effective adsorbent for the removal of sulfate from aqueous solution. The influence of various parameters such as sulfate initial concentration, pH, adsorbent dose and stirring time has been studied for the adsorption of sulfate in batch mode. Effects of foreign anions on the adsorption of sulfate onto RDPS have been also investigated. The pseudo-second-order, Elovich and intraparticle diffusion kinetic models have been developed to predict the rate constants of adsorption and equilibrium capacities. The maximum adsorption capacity of sulfate （qe ≈3.2 mg/g） onto RDPS was reached for the initial sulfate concentration = 100 mg/L, pH - 3.5, adsorbent dose = 10 g/L and for a stirring intensity = 200 rpm at 25 ± 2 ℃. The results showed that the adsorption of sulfate onto this raw materials followed pseudo-second-order rate kinetic predicting a chemisorption process.
文摘Because of socio-economic importance of date palm in North Africa, the scientific community has always followed the progression of parasitic disease that affects it. The study was performed on population of thirty palm trees belonging to three cultivars of the oases of south-west Algeria TOUAT Gourara. The analytical protocol consists of a hot hydrochloric acid hydrolysis of I g of leaf material dried and ground. Structural analysis of compounds present in extracts was conducted by chromatographic and spectrophotometric techniques. Through the analysis of all HPLC profiles of phenolic acids, we have established three chemotypes： resistant with the highest heights, sensitive, with the lowest height, finally low sensitivity or tolerant with intermediate heights. The increased synthesis of C-glycoflavones, within diseased palms, can be seen as the first sign of plant response to fungal attack, or even as a defense mechanism so these flavonoids correspond to ＂pre-inhibitines＂. It has not been found qualitative differences between different cultivars studied. The merits of our work show a negative correlation between flavonoid content and the level of lignification in the date palm, suggests that the process of lignification is more rapid in resistant cultivars. We can say that there is a constitutive resistance.
