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Prevalence of refractive errors among primary school children in a tropical area,Southeastern Iran

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Asian Pacific Journal of Tropical Biomedicine 2016年第2期6卷 181-184页

作者： Monireh Mahjoob Samira Heydarian jalil Nejati alireza Ansari-Moghaddam Nahid Ravandeh Department of Optometry School of Paramedical Science Mashhad University of Medical Sciences Health Promotion Research Center Zahedan University of Medical Sciences

Objective: To determine the prevalence of refractive errors among primary school children in Zahedan District, Southeastern Iran, as a tropical ***: In this cross sectional study, a total of 400 students were selected randomly using multi-stage sampling technique. Myopia was defined as spherical equivalent(SE)of-0.5 diopter(D) or more, hyperopia was defined as SE of +2.00 D or more and a cylinder refraction greater than 0.75 D was considered astigmatism. Anisometropia was defined as a difference of 1 D or more between two eyes. Cycloplegic refractive status was measured using auto-refractometer(Topcon 8800). Data were analyzed using SPSS,version 22 software ***: Mean ± SD of SE was(1.71 ± 1.16) D. A total of 20 students [6.3%, 95%confidence interval(CI): 3.96%–9.64%] were myopic(-0.5 D), 186 students(58.1%,95% CI: 52.50%–63.56%) were hyperopic( +2.00 D) and 114 students(35.6%, 95%CI: 30.43%–41.18%) were emmetropic. The prevalence of astigmatism( 0.75 D)among students was 3.4%(95% CI: 1.82%–6.25%). Anisometropia of 1 D or more was found in 21.3%(95% CI: 16.98%–26.23%) of the studied population. The prevalence of refractive errors was higher among girls than boys(73.1% vs. 55.6%, P = 0.001), but it was not significantly different among different age groups(P = 0.790).Conclusions: Refractive errors affect a sizable portion of students in Zahedan. Although myopia is not very prevalent, the high rate of hyperopia in the studied population emphasizes its need for attention.

关键词： Refractive error Myopia Hyperopia Astigmatism Anisometropia

Evaluation of Organic Matter Richness of Eocene Strata Based on Calcareous Nannofossils and Rock-Eval Analysis in North Dezful, Iran

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Journal of Earth Science 2021年第4期32卷 1022-1034页

作者： Mohammad Parandavar jalil Sadouni Exploration Directorate of the National Iranian Oil Company Studies and Researches OfficeTehranIran Department of Geology Faculty of sciencesFerdowsi University of MashhadMashhadIran

Hydrocarbon source potential of the Paleogene Pabdeh Formation was studied by means of organic geochemistry and distribution of calcareous *** on the results,an Eoceneaged organic matter(OM)-rich interval was identified and traced across different parts of the North Dezful zone and partly Abadan *** order to characterize the OM quality and richness of the studied intervals,Rock-Eval pyrolysis and nannofossils evaluation were performed,and the geochemical data collected along selected wells were correlated to capture the variations of thickness and source potential of the OM-rich ***,remarkable variations were identified within the depth ranges of 2480–2552 m and also 2200–2210 m,which were attributed to the maximum increase in the rate of growth R-selected *** increase in the productivity rate was found to be well correlated to high Rock-Eval total organic carbon(TOC)and hydrogen index(HI)*** that the maturity of Pabdeh Formation in the studied area was found to have reached the oil window,we expect significant hydrocarbon generation(Type II kerogen),making the play economically highly promising.

关键词： calcareous nannofossils Rock-Eval organic geochemistry Paleogene paleo-productivity diversity Dezful

Characteristics of the First Occurrence of Jurassic Petroleum in the Zagros Basin, Iran

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Acta Geologica Sinica(English Edition) 2018年第6期92卷 2280-2296页

作者： Sadouni jalil Rabbani AHMADREZA AmirKabir University of Technology Faculty of Petroleum Engineering

After two well tests in the Asmari well#A, located in the North Dezful zone, it was concluded that in the Jurassic Mus/Alan/Neyriz and Upper Sargelu reservoirs, highly mature colorless oil and gas were trapped, including 4%-6% H2 S. The alternation of Garau shale and the Gotnia anhydrite seal was so efficient that it did not allow the upward migration of petroleum from Jurassic reservoirs to higher levels. Descriptive ratios, chromatograms, pick correlation and cross plots demonstrated that the oil and gas have been derived from a TOC-enriched sequence, consisting of the base of the Garau and the top of the Sargelu Formations. This highly organic matter-rich sequence is traceable as an oil shale in other parts of the North Dezful zone, such as the Gashun section. The petroleum accumulations in both reservoirs are identical, have the same maturity and the same source. Diagrams of δ13 C2 versus δ13 C3, δ13 C1 versus wetness of gas(C1/C2+C3) and δ13 C1 versus δDC1 suggest that the gas is derived from a highly mature source. There are indications of TSR effects on the original petroleum that could have changed the volumetric and isotopic composition of the oil and gas. This result requires more careful study of the petroleum components to be undertaken.

关键词： isotope wetness enrichment migration oil shale

An analytical framework for the incorporation of non-orthogonal pilots in massive MIMO systems

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Digital Communications and Networks 2024年第5期10卷 1267-1279页

作者： Navid Pourjafari jalil Seifali Harsini Department of Electrical Engineering The University of Guilan

Training-based cellular communication systems use orthogonal pilot sequences to limit pilot ***,the orthogonality constraint imposes a certain pilot length,and therefore,in communication systems with a large number of users,time-frequency resources are wasted significantly in the training *** cellular massive MIMO systems,the time-frequency resources can be used more efficiently by replacing the orthogonal pilots with shorter non-orthogonal pilot sequences in such a way that more space is available for the transmission of additional data symbols,and thus achieving higher data *** course,the use of non-orthogonal pilots introduces additional pilot contamination,so the performance improvement could be achieved under certain system conditions,which are thoroughly investigated in this *** first provide a performance analysis framework for the uplink of cellular massive MIMO systems in which the effect of user pilot non-orthogonality has been analytically *** this framework,we derive analytical expressions for the channel estimation,user Signal-to-Interference-plus-Noise-Ratio(SINR),and the average channel capacity per *** then use the proposed framework to evaluate the achievable spectral efficiency gain obtained by replacing orthogonal pilots with non-orthogonal *** particular,the existing trade-off between pilot lengths and the additional data symbols that can be transmitted by reducing the number of pilot symbols,is numerically quantified over a wide range of system parameters.

关键词： Massive MIMO Non-orthogonal pilots Cellular systems Performance analysis

Experimental investigation and adaptive neural fuzzy inference system prediction of copper recovery from flotation tailings by acid leaching in a batch agitated tank

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International Journal of Minerals,Metallurgy and Materials 2019年第5期26卷 538-546页

作者： jalil Pazhoohan Hossein Beiki Morteza EsfANDyari Department of Chemical Engineering Quchan University of Technology Department of chemical engineering University of Bojnord

The potential of copper recovery from flotation tailings was experimentally investigated using a laboratory-mixing tank. The experiments were performed with solid weight percentages of 30 wt%, 35 wt%, 40 wt% and 45 wt% in water. The measurements revealed that adding sulfuric acid all at once to the tank rapidly increased the efficiency of the leaching process, which was attributed to the rapid change in the acid concentration. The rate of iron dissolution from tailings was less than when the acid was added gradually. The sample with 40 wt% solid is recommended as an appropriate feed for the recovery of copper. The adaptive neural fuzzy system(ANFIS) was also used to predict the copper recovery from flotation tailings. The back-propagation algorithm and least squares method were applied for the training of ANFIS. The validation data was also applied to evaluate the performance of these models. Simulation results revealed that the testing results from these models were in good agreement with the experimental data.

关键词： flotation tailings leaching copper environments adaptive neural fuzzy inference system

Oxidation Properties in CO_2 of Inconel Alloy 600 Coated by Simultaneous Aluminizing-Chromizing Process

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Chinese Journal of Aeronautics 2007年第2期20卷 134-139页

作者： Ahmed Moosa jalil Karim Ahmed Ali Hoobi The University of Technology Baghdad-Iraq Ministry of Labor and Social Affairs Baghdad-Iraq Ministry of Science and Technology Baghdad-Iraq

IN 600 alloy was coated with two different types of coatings, Cr-modified aluminide coating this is called aluminizing-chromizing and Y-doped chromium modified aluminide coating this is called aluminizing-chromizing-yttriumizing. Diffusion coating was carried at 1 050℃ for 8 h under Ar atmosphere by simultaneous aluminizing-chromizing process and by simultaneous aluminizing-chromizing- yttriumizing. Cyclic oxidation tests were conducted on the uncoated and on the coated Inconel 600 alloy in the temperature range 800- 1 000℃ in CO2 for 100 h at 10 h *** results showed that the oxidation kinetics for uncoated Inconel 600 alloy in CO2 is parabolic and the phases present are NiO, （Fe, Cr）2O3 , NiFe2O4 and NiCrO4. The oxidation kinetics for both coated systems in CO2 was found to be parabolic and the value ofkp for both coated systems were found to be lower than that for uncoated Inconel 600 alloy. Oxide phases that formed on coated systems are Al2O3 and NiCrO4. The role of yttrium can be attributed to its ability to improve the adherence of the oxide scale.

关键词： Inconel oxidation diffusion bonding aluminizing-chromizing Ni-superalloy

Study of Hydrogen Adsorption on Pt/WO_3-ZrO_2 through Pt Sites

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Journal of Natural Gas Chemistry 2007年第3期16卷 252-257页

作者： Sugeng Triwahyono Aishah Abdul jalil Hideshi Hattori Ibnu Sina Institute for Fundamental Science Studies Faculty of SciencesUniversiti Teknologi Malaysia81310 UTM SkudaiJohorMalaysia Faculty of Chemical & Natural Resources Engineering Universiti Teknologi Malaysia81310 UTM SkudaiJohorMalaysia Center for Advanced Research of Energy Technology Hokkaido UniversityNishi 5Kita 8Sapporo060-0808Japan

The rate determining step and the energy barrier involved in hydrogen adsorption on Pt/WO3- ZrO2 were studied based on the assumption that the hydrogen adsorption occurs only through Pt sites. The rate of hydrogen adsorption on Pt/WOa-ZrO2 was measured in the adsorption temperature range of 323-573 K and an initial hydrogen pressure of 50 Torr. The rates of hydrogen uptake were very high for the initial few minutes and the adsorption continued for more than 5 h below 523 K. The hydrogen uptake far exceeded the H/Pt ratio of unity for all adsorption temperatures, indicating that the adsorption of hydrogen involved the dissociative adsorption of hydrogen on Pt sites to form hydrogen atoms, the spillover of hydrogen atoms onto the surface of the WO3-ZrO2 catalyst, the diffusion of spiltover hydrogen atom over the surface of the WO3-ZrO2 catalyst, and the formation of protonic acid site originated from hydrogen atom by releasing an electron in which the electron may react with a second hydrogen atom to form a hydride near the Lewis acid site. The rate determining step was the spillover with the activation energy of 12.3 kJ/mol. The rate of hydrogen adsorption cannot be expressed by the rate equation based on the assumption that the rate determining step is the surface diffusion. The activity of Pt/WO3-ZrO2 was examined on n-heptane isomerization in which the increase of hydrogen partial pressure provided positive-effect on the conversion of n-heptane and negative-effect on the selectivity towards iso-heptane.

关键词： Pt/WO3-ZrO2 Pt sites hydrogen adsorption spillover n-heptane isomerization

Fabrication of Fe–TiC–Al_2O_3 composites on the surface of steel using a TiO_2–Al–C–Fe combustion reaction induced by gas tungsten arc cladding

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International Journal of Minerals,Metallurgy and Materials 2016年第2期23卷 193-204页

作者： Mahmood Sharifitabar jalil Vahdati Khaki Mohsen Haddad Sabzevar Department of Metallurgical and Materials Engineering Faculty of Engineering Ferdowsi University of Mashhad Department of Materials Engineering Faculty of Engineering University of Sistan and Baluchestan

The aim of the present study was to fabricate Fe-TiC-Al2O3 composites on the surface of medium carbon *** this purpose,TiO2-3C and 3TiO2-4Al-3C-xFe（0 ≤ x ≤ 4.6 by mole） mixtures were pre-placed on the surface of a medium carbon steel *** mixtures and substrate were then melted using a gas tungsten arc cladding *** results show that the martensite forms in the layer produced by the TiO2-3C ***,ferrite-Fe3C-TiC phases are the main phases in the microstructure of the clad layer produced by the 3TiO2-4Al-3C *** addition of Fe to the TiO2-4Al-3C reactants with the content from 0 to 20wt%increases the volume fraction of particles,and a composite containing approximately 9vol%TiC and A12O3 particles *** composite substantially improves the substrate *** mechanism by which Fe particles enhance the TiC ＋ A12O3 volume fraction in the composite is determined.

关键词： composite coatings iron-based materials combustion cladding microstructure microhardness

A Self-propagating high-temperature synthesis process for the fabrication of Fe（Cr）–Al2O3 nanocomposite

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International Journal of Minerals,Metallurgy and Materials 2019年第6期26卷 775-786页

作者： Seyed Esmaiel Shakib Ramin Raiszadeh jalil Vahdati-Khaki Department of Metallurgy and Materials Science School of EngineeringShahid Bahonar University of KermanKerman ***Iran Department of Materials Science and Metallurgical Engineering Engineering FacultyFerdowsi University of MashhadMashhad ***Iran

Self-propagating high-temperature synthesis(SHS)was used to fabricate a Fe(Cr)–Al2O3 *** composite was fabricated by the reactions between the powders of Fe,Fe2O3,Cr2O3,and *** effect of blending ratio and mechanical activation of the initial powders and the precursor compressing pressure on the microstructure of the final product was studied by optical microscopy,scanning electron microscopy,transmission electron microscopy,and X-ray *** significance of the effect of each of the aforementioned parameters on the quality of the composite(assessed by measuring the compressive strength and wear resistance)was determined using a full-factorial design of experiments *** results showed that the best molar powder ratio that produced the most homogeneous product through a sustainable SHS reaction was Fe:Fe2O3:Cr2O3:Al=10:1:1:4.A lower Fe content caused the Fe(Cr)phase to melt and separate from the rest of the materials.

关键词： self-propagating high temperature synthesis phase separation mechanical activation iron-chrome nanocomposite