Search Results/Filters    

Filters

Year

Banks



Expert Group











Full-Text


Issue Info: 
  • Year: 

    2025
  • Volume: 

    16
  • Issue: 

    3
  • Pages: 

    1027-1041
Measures: 
  • Citations: 

    0
  • Views: 

    0
  • Downloads: 

    0
Abstract: 

In recent years, the demand for new trenchless methods has dramatically risen. Pipe jacking is a trenchless method widely used in recent years. Ground deformation is one of the significant parameters that may lead to unrepairable harm to facilities and even people. So, ground deformation analysis is necessary for safety and design reasons. The present study analyzes the factors affecting ground deformation during pipe jacking. This is a descriptive-interventional study. Pipe jacking causes soil displacement in three dimensions (3-D). Therefore, 3-D numerical methods were applied for analysis. In this study, numerical simulation was performed using PLAXIS finite element numerical software, taking the case study into account. The effect of each parameter on the ground deformation pattern was studied in three directions; the uplift and their exact position were then analyzed. It should be noted that displacement analyses were performed in two areas: pipe crown and ground surface. Also, the relation of each parameter was estimated with the ground subsidence. Finally, the effect of each different factor and their sensitivity index were determined using sensitivity analysis. The highest subsidence occurs at the end of the shield due to stress relaxation. Considering the results, it was found that the relationship between the internal friction angle and subsidence is linear and direct. The relationship between the elastic modulus and subsidence is also linear but indirect. The results indicate that the most sensitive factor of ground deformation is the diameter, but the least sensitive factor is the face pressure.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

View 0

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesDownload 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesCitation 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesRefrence 0
Issue Info: 
  • Year: 

    2016
  • Volume: 

    4
  • Issue: 

    2
  • Pages: 

    21-28
Measures: 
  • Citations: 

    0
  • Views: 

    292
  • Downloads: 

    151
Abstract: 

This study presents a new mechanical tube cladding process named punch plastic deformation pipe cladding (PPDPC) based on local deformation by pressing a punch into the inner layer of the bimetal tube. To investigate the capability of the process, stainless steel tube (as the inner layer) is bonded to a carbon steel pipe (as the outer layer) to fabricate a bimetal pipe. Shear punch tests were used to evaluate the bond strength between layers. Also, optical microscopy (OM) was employed to investigate the bonding interface.Experimental results showed an excellent bonding at the interface of two layers. Shear punch test results showed that the bonding achieved from this new method is stronger than the conventional thermo-hydraulic cladding method. This process is influenced by several parameters including punch diameters, punch nose radius and the friction coefficient between the punch and cladding tube.The effects of these parameters were evaluated by finite element (FE) analysis. Good bonding, simplicity, lower cost and no change in the microstructure of the main pipe (outer layer) are the major advantages of this process.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

View 292

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesDownload 151 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesCitation 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesRefrence 0
Issue Info: 
  • Year: 

    2016
  • Volume: 

    13
  • Issue: 

    3
  • Pages: 

    19-33
Measures: 
  • Citations: 

    0
  • Views: 

    1029
  • Downloads: 

    0
Abstract: 

The behavior of the buried pipes under the fault displacement is a complex issue. In the past earthquakes, fault displacement of 2.1, 3 and 4 meters have been reported. A review on the literature shows that understanding failure modes of buried pipelines under big fault displacement is considered as a challenge. In this paper, the objective is to investigate the influence of the thickness parameters of the pipe on pipe behavior at pipe intersection and fault. The behavior of the pipe is studied focusing on fault displacements greater than 1 meter. Using finite element ABAQUS software, the simulation was performed through dynamic analysis regarding to pipe-soil interaction. Pipe and soil Dimensions and material properties of the soil and pipe are fixed in all analyzed samples and, the fault displacement (0.2 to 3 meters) and the pipe thickness (from 8.2 to 20 mm) are variable parameters of this article. An analysis has been conducted for the two variables (fault displacement and the thickness of the pipe). Maximum axial strain values and pipe deformation modes under fault displacement are discussed. Likewise, the influence of pipe thickness and the amount of fault displacement on the value of strain of the pipe wall is indicated in numerical analysis in the result. In the displacement of less than 1 meter, the pipes are like the letter S and local buckling occurs in the pipeline. In the displacement of 1.5 meters and more, they are like the letter Z, and pipe deformation and wrinkling occur in the pipeline. In the displacement of more than 1.5 meters, distortion, and wrinkling pipe is deformed. In the displacement of more than 1 m, the strain decreases with increasing pipe thickness. Through the change of the pipe thickness, the pipe failure mode changes.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

View 1029

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesDownload 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesCitation 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesRefrence 0
Issue Info: 
  • Year: 

    1385
  • Volume: 

    1
Measures: 
  • Views: 

    421
  • Downloads: 

    0
Keywords: 
Abstract: 

کوه زراب که در منطقه جنوب بافت و در حاشیه شمالی زون سنندج - سیرجان واقع گردیده است متشکل از سنگهای دگرگونی ارتوگنیس، مرمر انواع شیست می باشد بررسی های انجام شده نشان می دهد که این منطقه شامل ساختار فلسی بوده که راندگی ها بوضوح در آن دیده می شوند چین خوردگی های موجود در منطقه را میتوان به دو دسته لغزشی - خمشی و جریانی تقسیم نمود که تمایل چین ها با جهت رانده شدگی کلی منطقه همخوانی دارد.بررسی های صحرایی نشان دهنده 5 مرحله دگر شکلی در منطقه به شرح زیر می باشد: 1- ایجاد کشیدگی و تشکیل بودین های اولیه 2- وارد آمدن نیروهای فشارش عمود بر جهت تراست شدگی منطقه تشکیل تراست اصلی و راندگی های وابسته به آن به همراه چین های اصلی منطقه 3- فشارش مجدد و ایجاد چین های کشیده و ثانویه دریال چین های اولیه 4- کشیدگی مجدد و ایجاد گسلش نرمال در منطقه 5- آخرین مرحله دگرشکلی شامل فشارش مجدد که عامل تشکیل درزه های برشی و همچنین درزه های کششی عمود بر جهت تراست شدگی و فعالیت مجدد گلهای تراستی در منطقه می باشند.

Yearly Impact:   مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

View 421

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesDownload 0
Author(s): 

HASHEMI S.M. | ABBASI H.

Issue Info: 
  • Year: 

    2006
  • Volume: 

    24
  • Issue: 

    80-81
  • Pages: 

    110-113
Measures: 
  • Citations: 

    0
  • Views: 

    1581
  • Downloads: 

    0
Abstract: 

Introduction: The aim of this study is evaluation of efficacy of lacrimal sac localization with lacrimal probe without using light pipe. The study was based on nonrandomized prospective clinical trial with one year follow up period.Methods: A group of 40 patients operated since march 2001 to December 2004 The operation was Endoscopic Dacryocystorhynostomy and localization of lacrimal sac, which was performed with a lacrimal probe inserted in lacrimal sac. With pushing the probe inferomedialy pierces lacrimal sac lacrimal bone, and nasal musca over the bone. Follow up includes symptom evaluation such as epiphora and endoscopy. Success was defined as relief of symptoms & duct patancy with irrigation for a 1 year period.Results: 29 patients were male (72.5 %) and 11 were female (27.5 %). Mean age was 37.5 (with SD±12.26) in 20 patients right eye involved, left eye involved in 16 cases and in 4 cases both eyes involved. For 3 patients septoplasty was done besides EDCR. success rate was 82.5% and no complication was seen.Discussion: the use of lacrimal probe for lacrimal sac localization is a safe and easy method and don't have light pipe limitations then can replace light pipe.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

View 1581

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesDownload 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesCitation 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesRefrence 0
Issue Info: 
  • Year: 

    2009
  • Volume: 

    5
  • Issue: 

    2 (16) (STRUCTURES AND MATHERIALS MECHANICAL BEHAVIOR)
  • Pages: 

    51-63
Measures: 
  • Citations: 

    0
  • Views: 

    857
  • Downloads: 

    0
Abstract: 

Predicting the status of contact between the pipe and the roll through deformation is considered as one of the problems of reshaping process in non-circular pipe production. In the present study, the elastic-plastic analysis is investigated assuming plane strain condition for reshaping process. One of the problems of the mentioned process is the separation of pipe from roll in some zones. The proposed model has the capability of predicting the separation of the pipe from roll, which results in better prediction of the defect. To verify the reliability of the present contact model, the result of the analysis was compared to those of experimental ones and showed good agreements.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

View 857

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesDownload 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesCitation 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesRefrence 0
Issue Info: 
  • Year: 

    2024
  • Volume: 

    9
  • Issue: 

    1
  • Pages: 

    1843-1853
Measures: 
  • Citations: 

    0
  • Views: 

    24
  • Downloads: 

    20
Abstract: 

Double-pipe heat exchangers are commonly used in various industries, including power plants, solar cells, refineries, and automotive. The double-pipe heat exchanger is one of the most used simple exchangers in the industry. In this study, we employ computational fluid dynamics to investigate the flow characteristics of nanofluids within a double-pipe heat exchanger featuring a square inner tube and a circular outer tube (SC). The simulations are conducted under constant heat flux conditions, exploring laminar and turbulent flow regimes. Numerical results for water flow under forced convection are compared with reference results for validation. The results indicate that as the Reynolds number increases, particularly in turbulent flow regimes, the Nusselt number in nanofluid flow increases more than in water flow. For instance, in the case of aluminum oxide nanofluid flow at a Reynolds number of 500, the Nusselt number demonstrates a nearly 5% enhancement over water flow. In contrast, at a Reynolds number of 20000, this enhancement escalates to approximately 20%. Three types of nanoparticles are considered to investigate the effect of nanoparticle type on heat transfer and pressure drop. The results show that the use of nanoparticles has a slight effect on the friction factor while significantly enhancing heat transfer.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

View 24

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesDownload 20 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesCitation 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesRefrence 0
Author(s): 

BEHZAD M.

Issue Info: 
  • Year: 

    1999
  • Volume: 

    22
  • Issue: 

    1
  • Pages: 

    0-0
Measures: 
  • Citations: 

    1
  • Views: 

    616
  • Downloads: 

    0
Keywords: 
Abstract: 

To divert water from a large diameter irrigation pipeline to a smaller diameter plastic gated pipe so called "Hydroflume", a pipe turnout was designed and built in the Sugar cane development and Byproducts Company with the cooperation of the Shahid Chamran University, Ahwaz, Iran. This pipe turnout not only conveys water but it also dissipates the excess energy. The structure has of a circular broad crested weir for measuring flow discharge. It also was equipped by a piezometer to facilate flow measurement. The turnout consists of two 800-millimeters precast concrete pipe and has been designed in such a way that can be produced in large quantities in the factory and then installed in the farm. In this paper the design criteria including: investigation of various alternatives and selection of the best type, hydraulics and structural design, laboratory and field tests are presented.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

View 616

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesDownload 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesCitation 1 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesRefrence 0
Issue Info: 
  • Year: 

    2024
  • Volume: 

    38
  • Issue: 

    2
  • Pages: 

    171-181
Measures: 
  • Citations: 

    0
  • Views: 

    65
  • Downloads: 

    32
Abstract: 

IntroductionMore than 80 viral diseases of grapevines have been reported worldwide. The infectious degeneration disease complex causes growth reduction, stunting, shortening of internodes, bushy growth and decline in susceptible vines. Grapevine fanleaf viruses (GFLV), arabis mosaic virus (ArMV), grapevine deformation virus (GDefV), tomato ring spot virus (ToRSV) and tobacco ring spot virus (TRSV), which belong to the genus Nepovirus, are known to cause infectious degeneration. The genus Nepovirus has been divided into three subgroups A, B and C based on genome length, genomic organization, serological relationships, proteinase cleavage sites and the phylogenetic relationship of their coat protein (CP) gene. GDefV with the new name Nepovirus deformationis belongs to subgroup A of the genus Nepovirus and is closely related to ArMV and GFLV. Prevalence of GFLV in the vineyards of Iran raises the possibility that a mixed infection of GFLV and GDefV is also present in these areas. In Khorasan-Razavi Province, Iran's third-largest grape production center, research has addressed grape-affecting viruses with potential economic consequences, including reduced yield and product quality. Studying the distribution and genetic diversity of GDefV and other grape viruses is crucial for developing effective management and prevention strategies in the region's vineyards. In this study, GDefV was identified in the vineyards of Khorasan-Razavi province in Northeastern Iran and its complete genome was sequenced. In addition, the phylogenetic relationship of these isolates to other GDefV isolates deposited in GenBank was analyzed. Materials and MethodsSamples from three grapevines were collected from a vineyard in Kashmer, Khorasan-Razavi Province; total RNA was extracted from the petiole of young leaves using the CTAB-PVPP method., GDefV and mixed infections of GDefV/GFLV were detected by PCR using specific primers. The PCR products were electrophoresed in a 1% agarose gel and sequenced. The miRNAs were extracted from grapevine petiole tissue using the modified CTAB method, and small RNA libraries were prepared using the TruSeq Small RNA Sample Prep Kit and sequenced on the Illumina Novaseq 6000 platform. After trimming the reads, contigs were generated using k-mer 15 in Velvet assembler 0.7.31. Contigs were verified using BLASTn and BLASTx in NCBI, and reconstruction of the GDefV genome from the NGS reads was performed using CLC Genomics Workbench (CLC Bio) software. Phylogenetic trees were generated in MEGA7 using the maximum likelihood (ML) method with 1000 replicates in the bootstrap test. The occurrence of possible recombinations in the GDefV genome was analyzed using the RDP v.6 package. Results and DiscussionThe samples showed leaf deformation, shortening of internodes, bushy growth, stunting and decline, but these symptoms are probably related to GFLV, and GDefV only causes leaf deformation in the infected vine. The PCR amplification and sequencing of a segment of the coat protein gene revealed a co-infection of GDefV and GFLV in the samples. GFLV is widely distributed in Iranian vineyards, GDefV has also been previously reported in the vineyards of northwestern Iran, but this is the first report of GDefV in the vineyards of Khorasan-Razavi Province.After refining the reads, approximately 15 million reads (92-99.7% of the original reads) remained for further analysis. The read sequences of each library were deposited in the Sequence Read Archive (SRA) under the accession number SAMN33747579-81. Three Iranian GDefV isolates obtained from three miRNA libraries were deposited in GenBank (accession numbers **-**).RNA1 and RNA2 of the three Iranian GDefV isolates had a length of 7386 and 3753 nucleotides, respectively. The RNA1 in GDefV had an open reading frame (ORF) of 6852 nucleotides in length, which started with the start codon AUG at position 288 and ended with the stop codons UAA or UAG at position 7142. The 5' end of the genome had 287 nucleotides long and contained two repeating sequences of 15 nucleotides that formed stem-loop structures. The length of the non-coding region at the 3' end had 244 nucleotides. Translation of RNA1 of the GDefV genome produces a polyprotein (p1) of 2285 amino acids (approximately 252 kda). The polyprotein p1 comprises the cofactor proteins proteinase, helicase, VPg, proteinase and polymerase with approximate weights of 45, 88, 3, 25 and 91 kDa, respectively. RNA2 also has one ORF, located between nucleotides 237 and 3560. This open reading frame also produces a 122 kDa polyprotein (P2) with 1108 amino acids. The second fragment of the GDeFV genome had 236 nucleotides as a 5'-noncoding region with three repeating sequences of 15 nucleotides that produced stem-loop structures with a 3-nucleotide loop and a 6bp stem. The 3'-noncoding region was also 193 nucleotides long. Polyprotein P2 comprised protein 2A, movement protein (MP) and coat protein (CP). The GDefV polyproteins had cysteine/alanine (C/A) and arginine/glycine (R/G) cleavage sites similar to those of the GFLV polyprotein. Comparison of the RNA1 sequences from three Iranian GDefV isolates with other GDefV isolates available in GenBank showed that the Iranian isolates had 88.1-92.2 % nucleotide identity with each other and 90.3-93.9 % with GenBank isolates at the nucleotide level. At the amino acid level, the Iranian isolates were 86.6-91.6 % identity with each other and 88.9-92.7 % with GenBank isolates. For RNA2, the Iranian isolates showed 89.4-92 % similar to each other and 89.6-94.2 % similar to GenBank isolates at the nucleotide level. The amino acid similarity between the Iranian GDefV isolates was 85-88.6 %. In the phylogenetic tree based on the nucleotide and amino acid sequences of RNA1 and RNA2 of the GDefV genome, the Iranian isolates of this study were clustered in a distinct clade than other GDefV isolates from Turkey (HE613269 and NC017939).GDefV was reported in 2003 and no further information is available on its distribution in vineyards around the world. GDefV has already been reported from Turkey and Iran, but the complete genome sequence of the Iranian GDefV isolate is being reported for the first time. Further studies on the population diversity of GDefV isolates in different regions of Iran are required to gain more insight into the mechanisms affecting the dynamics of GDefV populations.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

View 65

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesDownload 32 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesCitation 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesRefrence 0
Issue Info: 
  • Year: 

    2023
  • Volume: 

    53
  • Issue: 

    2
  • Pages: 

    44-49
Measures: 
  • Citations: 

    0
  • Views: 

    114
  • Downloads: 

    18
Abstract: 

In the 1970, Popov et al. Developed plans to make plastic joints in frames with eccentric bracing to increase energy dissipation (Roeder and Egor, 1978), and since the late 1980s, the use of steel dampers has been common in countries such as Japan and Indonesia. Has been. Different types of steel dampers have been used since then, for example ADAS, X-shaped and honeycomb dampers are some of the steel dampers that are still under development and research studies have been done on them (Askariani et al. 2020).

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

View 114

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesDownload 18 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesCitation 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesRefrence 0
litScript
email sharing button
telegram sharing button
whatsapp sharing button
linkedin sharing button
twitter sharing button
email sharing button
email sharing button
sharethis sharing button