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New approach for assessing the weldability of precipitation-strengthened nickel-base superalloys

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International Journal of Minerals,Metallurgy and Materials 2013年第12期20卷 1183-1191页

作者： Homam Naffakh Moosavy mohammad-Reza Aboutalebi seyed Hossein seyedein Meisam Khodabakhshi Carlo Mapelli School of Metallurgy and Materials Engineering Iran University of Science and Technology (IUST) MAPNA Turbine Engineering and Manufacturing Company (TUGA) Dipartimento di Meccanica Politecnico di Milano

A new procedure was proposed for evaluating the weldability of nickel-base superalloys. The theory is on the basis of two microstructural patterns. In pattern I, the weld microstructure exhibits severe alloying segregation, many low-melting eutectic structures, and low weldability. The weld requires a weaker etchant and a shorter time for etching. In pattern Ⅱ, the weld microstructure displays less alloying segregation, low quantity of eutectic structures, and high weldability. The weld needs a stronger etchant and a longer time for etching. Five superalloys containing different amounts of Nb and Ti were designed to verify the patterns. After welding operations, the welds were etched by four etchants with different corrosivities. The weldability was determined by TG-DSC measurements. The metallography and weldability results confirmed the theoretic patterns. Finally, the etchant corrosivity and etching time were proposed as new criteria to evaluate the weldability of nickel-base superalloys.

关键词： superalloys nickel alloys weldability metallography etching segregution eutectics

Influence of freeze-only and freezing-thawing cycles on splash erosion

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International Soil and Water Conservation Research 2018年第4期6卷 275-279页

作者： seyed Hamidreza Sadeghi mohammad Bagher Raeisi Zeinab Hazbavi Watershed Management Engineering Department Faculty of Natural ResourcesMember of Agrohydrology GroupTarbiat Modares UniversityNoor46417-76489Iran Watershed Management Engineering and Sciences Department of Watershed Management EngineeringFaculty of Natural ResourcesTarbiat Modares UniversityIran

Soil erosion is recognized as one of the most important types of land degradation in the world particularly in many developing countries like Iran. Water erosion is initiated by splash erosion triggered by raindrop impact. Understanding the process of splash erosion under freezing and thawing conditions is essential to unravel soil erosion mechanisms under temperate conditions leading to appropriate planning of soil and water conservation projects. The present study aimed to study the individual effects of freeze-only as well as freezing-thawing cycle on splash erosion in a loess soil from an erosion prone area in mountainous northern regions of Iran. The study was conducted under laboratory conditions using erosion plots. The erosion plots were subjected to freeze only and freeze-thawing treatments by simulating cold conditions using a large cooling compartment system specifically manufactured for this purpose. The splash erosion under a designed simulated rainfall (1.2mmmin-1 for 30 min) was then measured as upward, downward and net splash erosion in splash cups. The results showed that freeze only decreased the upward, downward and net splash erosion by 0.81 ± 0.43, 0.82 ± 0.29 and 0.85 ± 0.23% while freezing-thawing cycle decreased splash erosion to 0.93 ± 0.83, 0.61 ± 0.43 and 0.57 ± 0.36%. This may be attributed to temporary increase in soil strength and stability or surface sealing during freezing process leading to reduced splash erosion.

关键词： Experimental plots Freezing effects Rainfall simulation Soil detachment process

Higher Iterated Hilbert Coefficients of the Graded Components of Bigraded Modules

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Algebra Colloquium 2017年第4期24卷 551-562页

作者： seyed Shahab Arkian University of Kurdistan Pasdaran ST.P.O.Box:416Sanandaj Iran

Let S = K[x1,... ,xn] be the polynomial ring over a field K, and let I C S be a graded ideal. It is shown that the higher iterated Hilbert coefficients of the graded S-modules Tori^S（M,Ik） and Exts^i（M,Ik） are polynomial functions in k, and an upper bound for their degree is given. These results are derived by considering suitable bigraded modules.

关键词： higher iterated Hilbert coefficient bigraded module extension functor tor-sion functor

Collar performance in bridge pier scour with debris accumulation

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International Journal of Sediment Research 2022年第3期37卷 328-334页

作者： Hossein Hamidifar seyed mohammad Bagher Shahabi-Haghighi Yee Meng Chiew Water Engineering Department Shiraz University School of Civil and Environmental Engineering Nanyang Technological University

The mechanism of bridge pier scour becomes more complex in the presence of debris accumulation upstream of the pier. While using countermeasures may be effective in reducing scour, their efficacy could be undermined in such a situation. The current study investigates the effectiveness of using a collar in the presence of different types of floating debris accumulation in reducing scour around a cylindrical bridge pier with non-cohesive bed sediment. The experimental results reveal that using a collar can reduce the scour depth by up to 39% when compared to that without the collar in the absence of debris accumulation under the same flow conditions. Also, the collar’s efficiency is reduced by up to 25% when debris accumulation is present. However, depending on the relative size of the accumulated debris and collar, the effectiveness of collars may be increased as a pier-scour protection device. A new parameter,which is defined as the Debris Protrusion Ratio(DPR), is used to quantify the effect of debris layout size on scour depth. Moreover, a semi-empirical equation that may be used to predict the depth of the scour hole that forms around cylindrical collar-fitted piers with floating debris accumulation is proposed. The equation’s performance is evaluated using the available data in the literature. Based on the analysis, the current study shows that the accuracy of the proposed equation is satisfactory in predicting the maximum scour depth.

关键词： Bridge pier Scour Debris Collar Blockage

Comparison of different diagnostic methods in infants with Cholestasis

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World Journal of Gastroenterology 2006年第36期12卷 5893-5896页

作者： seyed Mohsen Dehghani Mahmood Haghighat mohammad Hadi Imanieh Bita Geramizadeh Department of Pediatric Gastroenterology Gastroenterohepatology Research Center of Nemazee Hospital Shiraz University of Medical Sciences Shiraz Iran Department of Pathology Nemazee Hospital Shiraz University of Medical Sciences Shiraz Iran

AIM: To evaluate different methods in differentiating idiopathic neonatal hepatitis from biliary atresia. METHODS: Sixty-five infants with cholestatic jaundice and final diagnosis of idiopathic neonatal hepatitis and biliary atresia were studied prospectively from September 2003 to March 2006. A thorough history and physical examination were undertaken and the liver enzymes were examined. All cases underwent abdominal ultrasonography, hepatobiliary scintigraphy, and percutaneous liver biopsy. The accuracy, sensitivity, specificity and predictive values of these various methods were compared. RESULTS: There were 34 girls and 31 boys, among them 46 subjects had idiopathic neonatal hepatitis (age, 61 ± 17 d) and 19 had biliary atresia (age, 64 ± 18 d). The mean age at onset of jaundice was significantly lower in cases of biliary atresia when compared to idiopathic neonatal hepatitis cases (9 ± 13 d vs 20 ± 21 d; P = 0.032). The diagnostic accuracy of different methods was as follows: liver biopsy, 96.9%; clinical evaluation, 70.8%; ultrasonography, 69.2%; hepatobiliary scintigraphy, 58.5%; and liver enzymes, 50.8%.CONCLUSION: Our results indicate that clinical evaluation by an experienced pediatric hepatologist and a biopsy of the liver are considered as the most reliable methods to differentiate idiopathic neonatal hepatitis and biliary atresia.

关键词： Idiopathic neonatal hepatitis Biliary atresia Clinical evaluation Liver biopsy

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Sound & Vibration 2019年第6期53卷 263-276页

作者： Jahede Tekeykhah seyed Mohsen hosseini Gholamali Jalali Jalil Alavi Abbas Esmaili Sari Forestry Department Natural Resources and Marine Sciences FacultyTarbiat Modares UniversityNoorMazandaranIran Faculty of Natural Resources Tarbiat Modares UniversityNoorMazandaranIran Associate Professor of Forestry Department Tarbiat Modares UniversityNoorMazandaranIran Forestry Department Tarbiat Modares UniversityNoorMazandaranIran Department of Environmental Science Tarbiat Modares UniversityNoorMazandaranIran

Sound pollution is one of the most important urban problems which endangers mental and physical health of the *** study was aimed to assess the influence of different tree species,including Fraxinus rotundifolia,Robinia pseudoacacia,Platanus orientalis,Platycladus orientalis,and Pinus eldarica,in reducing noise pollution in the Abidar Forest Park.A further objective was to identify the contaminated areas of Sanandaj city and to propose suitable noise absorbent tree species in consistent *** each tree stands the noise measurements were performed during intervals at frequencies of 250,500 and 1000 Hz,besides an open area with the same *** regards to the second purpose,a total of 50 stations with residential,commercial,residentialcommercial,and green space applications were selected across the *** Continuous Sound Pressure Level(Leq)was determined in five replicates for 30 *** measurements were performed under stable weather conditions and low wind velocity at 17:00(traffic peak)in summer and *** of the Leq values were above the threshold noise *** highest noise reduction was recorded in summer(i.e.,green season);Platanus and Platycladus species demonstrated the highest and lowest noise absorption(31.43 dB and 22.28 dB,respectively).Furthermore,a meaningful difference was observed between Leq values of commercial,residential,commercial-residential,and green space urban applications,and the central parts of the city showed noticeable noise *** together,due to being exposed to higher than the acceptable threshold noise level,the residents of Sanandaj will be endangered to health problems in the near future;thus consideration should be given to the noise pollution sources.

关键词： Urban green space noise attenuation Abidar Forest Park

Hydrocarbon Vertical Continuity Evaluation in the Cretaceous Reservoirs of Azadegan Oilfield, Southwest of Iran: Implications for Reservoir Geochemistry

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Acta Geologica Sinica(English Edition) 2020年第3期94卷 847-860页

作者： Bahram ALIZADEH Mehrab RASHIDI Alireza ZARASVANDI seyed Rasoul seyedALI mohammad Hasan ALIEE Department of Geology Faculty of Earth SciencesShahid Chamran University of AhvazAhvazIran Petroleum Geology and Geochemistry Research Center(PGGRC) Shahid Chamran University of AhvazAhvazIran Geochemistry Department Exploration DirectorateNational Iranian Oil Company(NIOC)TehranIran Geophysics Department Exploration DirectorateNational Iranian Oil Company(NIOC)TehranIran

A collection of data obtained from analytical methods in geochemistry along with the reservoir engineering and geologic data were used to investigate the reservoir continuity in the Cretaceous Fahliyan, Gadavan, Kazhdumi and Sarvak reservoirs of the super-giant Azadegan oilfield, SW Iran. The geochemical data indicate that the oil samples, with medium to high level of thermal maturity, have been generated from the anoxic marine marl/carbonate source rock(s). The Sargelu(Jurassic) and Garau(Cretaceous) formations are introduced as the main source rocks for the studied oils. The dendrogram obtained from the cluster analysis of high-resolution gas chromatography data introduces two main oil groups including Fahliyan reservoir, and Kazhdumi along with Sarvak/Gadvan reservoirs. This is confirmed by C7 Halpern star diagram, indicating that, the light oil fraction from Fahliyan reservoir is distinct from the others. Also, different pressure gradient of the Fahliyan Formation(over-pressured) relative to other reservoirs(normally-pressured) show the presence of compartments. The relation between toluene/n-heptane and n-heptane/methylcyclohexane represents the compartmentalization due to maturation/evaporative fractionation for Fahliyan and water washing for other studied reservoirs. Also, the impermeable upper part of the Fahliyan Formation and thin interbedded shaly layers in the Kazhdumi, Sarvak and Gadvan formations have controlled reservoir compartmentalization.

关键词： reservoir continuity geochemistry pressure gradient oil-oil correlation Azadegan oilfield Abadan Plain

Tectonic paleostress field and its impact on the geodynamic evolution of Central Iran, case study: the Shotori Mountain

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Journal of Mountain Science 2023年第10期20卷 3018-3034页

作者： Razieh ABBASPOUR seyed Morteza MOUSAVI Ahmad RASHIDI mohammad Mahdi KHATIB Shahram SHAFIEIBAFTI Department of Geology University of BirjandBirjand ***Iran Department of Earthquake Research Shahid Bahonar University of KermanKerman ***Iran International Institute of Earthquake Engineering and Seismology Tehran ***Iran Department of Geology Shahid Bahonar University of KermanKerman ***Iran

The Shotori mountain range is located along the northern terminus of the Nayband fault on the eastern and western domains of the Tabas and Lut blocks,*** range with NNW-SSE trending and approximately 120 km long includes a series of thrust faults approaching the right-lateral strike-slip Nayband *** the Shotori range has experienced various geological events since the Triassic,our investigations suggest that the basement of the Central Iranian subcontinent of the Shotori range contains the early Triassic deep sedimentary with normal faults which confirms Triassic tensional tectonic stress regime in the *** the middle Triassic,the mountain range has experienced thrust and strike-slip ***,in this study,we reconstruct the stress regimes for different geological periods using fault-slip *** inversion of faultslip data reveals drastic temporal changes in the maximum stress regime(σ1)over the Triassic,Jurassic,Cretaceous,Paleogene,Neogen,and *** reconstruction of the stress field based on the age and direction of fault movement reveals that the direction of the maximum horizontal stress axis(σ1)under a tensional stress regime was approximately N129°in the Early *** stress regime is the cause of thinning and subsidence of the Shotori sedimentary *** the middle Triassic,theσ1 direction was about N81°and the upper Triassic,theσ1 direction was almost N115°.The middle Triassic and upper Triassic stress states exhibited two distinct strike-slip and compressive stress *** stress regime led to the uplift of the Shotori sedimentary *** the Jurassic,the direction of the maximum horizontal stress axis(σ1)was~NW-SE under a compressive stress *** the Triassic,theσ1 direction was~*** stress regime led to the formation of the high topography of the Shotori Mountain *** the Late Cretaceous,the direction of the maximum horizontal stress axis(σ1)under the extensional stress

关键词： Paleostress Fault-slip data Geodynamics Shotori mountain range Tabas Central Iran

Efficient-Cost Task Offloading Scheme in Fog-Internet of Vehicle Networks

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Computer Systems Science & Engineering 2023年第5期45卷 2223-2234页

作者： Alla Abbas Khadir seyed Amin hosseini Seno Baydaa Fadhil Dhahir Rahmat Budiarto Department of Electrical Power Techniques Engineering Al-Hussain University CollegeKarbalaIraq Department of Computer Engineering Ferdowsi University of MashhadMashhadIran Department of Computer Science Thi-Qar UniversityThi-QarIraq Department of Computer Science Mercu Buana UniversityJakartaIndonesia

Fog computing became a traditional OffLad Destination(OLD)to compute the offloaded tasks of the Internet of Vehicles(IoV).Nevertheless,the limited computing resources of the fog node leads to re-offload these tasks to the neighboring fog nodes or the ***,the IoV will incur additional offloading *** this paper,we propose a new offloading scheme by utilizing RoadSide Parked Vehicles(RSPV)as an alternative OLD for *** idle computing resources of the RSPVs can compute large tasks with low offloading costs compared with fog nodes and the ***,a performance evaluation of the proposed scheme has been presented and discussed with other benchmark offloading schemes.

关键词： RoadSide parked vehicles offloading cost deadline budget