En
  • دکتری (1380)

    لوم و صنایع چوب و کاغذ

    دانشگاه تهران، کرج، ایران

  • کارشناسی‌ارشد (1374)

    چوب شناسی و صنایع چوب

    دانشگاه تهران، کرج، ایران

  • کارشناسی (1371)

    چوب شناسی و صنایع چوب

    دانشگاه تهران، کرج، ایران

  • کامپوزیت های چوب پایه
  • ارزیابی غیرمخرب چوب

    دکتر سعید کاظمی نجفی متولد 1348 در شهرستان نوشهر و دارای مدرک دکتری علوم و صناع چوب و کاغذ از دانشگاه تهران می باشد. از سال 1381 به عنوان عضو هیات علمی در گروه علوم و صنایع چوب و کاغذ دانشکده منابع طبیعی دانشگاه تربیت مدرس مشغول به کار شده است و در سال 1392 به مرتبه استادی نائل امده است.

    ارتباط

    رزومه

    Analysis of sediment accessibility and availability concepts based on sediment connectivity throughout a watershed

    Saeed Najafi, Seyed Hamidreza Sadeghi, Tobias Heckmann
    Journal PapersLand Degradation & Development , 2021 January , {Pages }

    Abstract

    The identification of the degree of linkage between sediment source and sink areas and also the channel network allows for prioritizing areas for sediment control measures at the watershed scale. The present study was therefore planned to investigate sediment connectivity based on structural and functional aspects. To that end, the index of connectivity (IC) and sediment delivery ratio (SDR) respectively were calculated based on the approaches of Borselli et al. (2008) and sediment contribution area (SCA) representing structural and functional sediment indices of connectivity. Results showed that high structural connectivity in an area does not necessarily result in high transportation of sediment, since structural connectivity only reflec

    Determining elastic constants of poplar wood (Populus deltoides) by ultrasonic waves and its application in the finite element analysis

    M Zahedi, S Kazemi Najafi, J Füssl, M Elyasi
    Journal Papers , , {Pages }

    Abstract

    Preparation of Polyurethane Adhesive from Wood Sawdust polyol: Application of Response Surface Methodology for Optimization of Catalyst and Glycerol

    S Daneshvar, R Behrooz, SK Najafi, GMM Sadeghi
    Journal Papers , , {Pages }

    Abstract

    Lightweight tubular fiberboard: Effect of hole diameters and number on panel properties

    Javad Khakzad, Ali Shalbafan, Saeed Kazemi-Najafi
    Journal PapersMaderas. Ciencia y tecnolog?a , Issue AHEAD, 2020 January , {Pages 0-0 }

    Abstract

    Special tubular fiberboard with a density of 550 kg/m 3 was manufactured using the round rods for creation of the holes. Physicomechanical properties of tubular fiberboard (6, 8, 10, 12 (mm)) with various hole diameters and number of hole (0, 1, 2 and 3 in a constant cross section) were evaluated. The surface layers density, especially on top of the holes, considerably elevated with increasing the hole diameter. This did create higher bending properties as well as higher internal bond and surface soundness. The structure of webs between the holes, when the holes’ number increases, were predominant factor influencing the panel properties. Weak and loose web structure were obtained by increasing the holes’ number from 1 to 3 within a cons

    Characterization of Engineering Elastic Parameters of Oriented Strand Board (OSB) Manufactured from Poplar

    Meysam Zahedi, Saeed Kazemi Najafi, Josef F?ssl, Majid Elyasi
    Journal PapersDRVNA INDUSTRIJA , Volume 71 , Issue 3, 2020 January , {Pages 219-226 }

    Abstract

    When using wood and wood-based composites, it is necessary to determine the elastic constants of these engineered materials. Oriented strand board (OSB), as structural wood based panel, plays a significant role in the building sector, but the accessibility of such elastic constants of OSB is mostly limited. For this purpose, this study aimed at determining the elastic wave velocity, stiffness and all elastic constants of OSB made from Poplar (Populus deltoides) strands using ultrasonic through–transmission technique. Laboratory OSBs with the mean density of 760 kg/m3 were made with the average strand sizes of 0.6 mm in thickness, 120 mm in length and 30 mm in width. 8% phenol-formaldehyde (PF) resin was used with the pressing conditions o

    Characterization of Engineering Elastic Parameters of Oriented Strand Board (OSB) Manufactured from Poplar (Populus deltoides) Strands Using Ultrasonic Contact Pulse Transmission

    Meysam Zahedi, Saeed Kazemi Najafi, Josef F?ssl, Majid Elyasi
    Journal PapersDrvna industrija: Znanstveni časopis za pitanja drvne tehnologije , Volume 71 , Issue 3, 2020 July 10, {Pages 227-234 }

    Abstract

    When using wood and wood-based composites, it is necessary to determine the elastic constants of these engineered materials. Oriented strand board (OSB), as structural wood based panel, plays a significant role in the building sector, but the accessibility of such elastic constants of OSB is mostly limited. For this purpose, this study aimed at determining the elastic wave velocity, stiffness and all elastic constants of OSB made from Poplar (Populus deltoides) strands using ultrasonic through–transmission technique. Laboratory OSBs with the mean density of 760 kg/m3 were made with the average strand sizes of 0.6 mm in thickness, 120 mm in length and 30 mm in width. 8% phenol-formaldehyde (PF) resin was used with the pressing conditions o

    Karakterizacija parametara elastičnosti ploče s orijentiranim makroiverjem (OSB) proizvedene od iverja drva topole (Populus deltoides) uz pomoć ultrazvučnoga kontaktnog?…

    Meysam Zahedi, Saeed Kazemi Najafi, Josef F?ssl, Majid Elyasi
    Journal PapersDrvna industrija: Znanstveni časopis za pitanja drvne tehnologije , Volume 71 , Issue 3, 2020 July 10, {Pages 227-234 }

    Abstract

    Za primjenu drva i kompozita na bazi drva iznimno je važno odrediti konstante elastičnosti tih konstrukcijskih materijala. Ploča s orijentiranim makroiverjem (OSB ploča), kao strukturna ploča na bazi drva, ima široku primjenu u građevnom sektoru, a pristup takvim konstantama elastičnosti OSB ploča uglavnom je ograničen. Stoga je cilj ove studije bio odrediti brzinu elastičnog vala, krutost i sve konstante elastičnosti OSB ploča proizvedenih od makroiverja topole (Populus deltoides) primjenom ultrazvučne tehnike. Od iverja prosječne debljine 0, 6 mm, duljine 120 mm i širine 30 mm laboratorijski su izrađene OSB ploče srednje gustoće 760 kg/m3. Upotrijebljena je 8%-tna fenol-formaldehidna (PF) smola u ovim uvjetima prešanja

    Comparison of Canola and Soy Flour with Added Isocyanate as Wood Adhesives

    Mahsa Barzegar, Rabi Behrooz, Hamid Reza Mansouri, Saeed Kazemi Najafi, Linda F Lorenz, Charles R Frihart
    Journal PapersJournal of the American Oil Chemists' Society , 2020 September 3, {Pages }

    Abstract

    Canola is widely grown in the northern latitudes for its vegetable oil, generating large quantities of residual, low value canola flour used as animal feed. The common wood adhesive poly(diphenylmethylene diisocyanate) (pMDI) should react with the wide variety of functional groups in proteins. Therefore, it would seem that canola flour with added pMDI could be an effective adhesive. Two main questions are addressed in this study: How do the wood adhesive properties of canola flour compare to the better‐studied soy flour? How well do proteins, which contain an abundance of functional groups, cure with the very reactive pMDI? These questions were addressed using the small‐scale adhesive strength test ASTM D‐7998, with various adhesive

    Sediment connectivity concepts and approaches

    Saeed Najafi, Deirdre Dragovich, Tobias Heckmann, Seyed Hamidreza Sadeghi
    Journal Papers , Volume 196 , 2020 January , {Pages 104880 }

    Abstract

    In recent years the concept of connectivity has emerged in sediment management to describe transfer of sediment from different sections of landscapes at various spatial and temporal scales. The sediment connectivity concept has two distinct components: structural and functional. Structural and functional sediment connectivities have a hard and soft nature, respectively, in which the former relates to physical characteristics and the latter to soil erosion and sediment transport processes. Although there has been an increase in sediment connectivity studies over the last decade, disagreement and confusion seems to remain about conceptual and especially methodological approaches, related indices, methods of quantifying sediment connectivity a

    The Effect of Chipping Method on the Geometry of Particles Produced from Date Palm Frond

    Neda Eghtedarnejad, Saeed Kazemi-Najafi, Ali Shalbafan
    Journal PapersBioResources , Volume 16 , Issue 1, 2020 November 2, {Pages 1131-1143 }

    Abstract

    The aim of this research was to study the effect of chipping method on geometry of particles obtained from date palm frond as a lignocellulose residue. For this purpose, date palm fronds were chipped with four different equipment: chipper-flaker, chipper-hammer mill, flaker-hammer mill, and chipper-flaker-hammer mill. The geometry of the particle including particle size, particle size distribution, shape, and aspect ratio were investigated. The results showed that maximum weight percentage (more than 40%) was related to the particles sizes of+ 30/-40 mesh for all chipping methods and more than 50% of all generated particles had a needle shape. In the chipper-hammer mill method, both the weight percentage of useable particles in particleboar

    The effect of hygro-thermo-mechanical modification on the applied properties of glulam made from poplar

    Reza Hajihassani, Behbood Mohebbi, Saeed Kazemi Najafi
    Journal PapersIranian Journal of Wood and Paper Industries , Volume 11 , Issue 2, 2020 August 22, {Pages 241-253 }

    Abstract

    The objective of this study was to investigate the physical and mechanical properties of glulam made from compressed poplar wood (Populus deltoides) by technique of Combined Hygro-Thermo-Mechanical Treatment (CHTMT) which is combination of two techniques of hygrothermal treatment and densification of wood. The poplar wood blocks were initially treated hygrothermally at temperatures of 130, 150, and 170?C for holding times of 20 and 40 minutes. Afterwards, the densification process was carried out under a hot press (at 160?C for 20 minutes) at two levels of compression set, i.e. 40 and 60 percent based on the blocks thickness (radial direction). For production of glulam, the blocks were jointed together by finger joint and polyurethane resin

    Karakterizacija parametara elastičnosti ploče s orijentiranim makroiverjem (OSB) proizvedene od iverja drva topole (Populus deltoides) uz pomoć ultrazvučnoga kontaktnog …

    M Zahedi, SK Najafi, J Füssl, M Elyasi
    Journal Papers , , {Pages }

    Abstract

    Physical and Mechanical Properties of Wood-Plastic Composites Made with Microfibrillar Blends of LDPE, HDPE and PET

    Seyyedeh Tahereh Mosavi-Mirkolaei, Saeed Kazemi Najafi, Mehdi Tajvidi
    Journal PapersFibers and Polymers , Volume 20 , Issue 10, 2019 October 1, {Pages 2156-2165 }

    Abstract

    The effect of microfibrillar blends of recycled plastics on selected physical and mechanical characteristics of wood-plastic composites (WPCs) was investigated in this study. The production of wood plastic composites was carried out through a two-step extrusion technique. The plastic blends were drawn after extrusion to obtain microfibrillar morphology. The addition of polyethylene-co-glycidyl methacrylate (E-GMA) enhanced compatibility between the two phases and a homogenous structure was seen in the fracture surfaces by scanning electron microscopy (SEM). The crystallinity of base polymers increased with the addition of polyethylene terephthalate (PET) microfibrils, E-GMA and wood flour. The X-ray diffraction (XRD) patterns

    Comparison of the Preliminary Effect of Micro-Catchment Rainwater Harvesting Systems on the Photosynthetic Activities of Almond Seedlings

    Saeed Najafi
    Journal PapersDesert Ecosystem Engineering Journal , Volume 8 , Issue 23, 2019 July 10, {Pages 73-84 }

    Abstract

    Introduction: Water deficit is one of the most important stress factors affecting plant growth and production in the worldwide, as due to series drought stress photosynthetic activities are negatively affected. Subsequently, a reduction will happen in the growth of leaves and plants, stomatal conductance and agricultural products. Accordingly, major concern exists in countries like Iran where water scarcity and poor water management in combination with increased population and water consumption endanger food security. Therefore, exploring ways to increase agricultural and horticultural products along with optimizing the use of water is essential. The aim of this paper is a) to examine the effects of Rain Water Harvesting (RWH) systems on ph

    Formaldehyde emission from PVC–wood composites containing MDF sanding dust

    Mahdi Ansari Chaharsoughi, Saeed Kazemi Najafi, Rabi Behrooz
    Journal PapersJournal of Vinyl and Additive Technology , Volume 25 , Issue 2, 2019 May , {Pages 159-164 }

    Abstract

    The main purpose of this work was to study the formaldehyde emission from wood plastic composites (WPCs) containing polyvinyl chloride (PVC), wood flour, and sanding dust of medium density fiberboard (MDF). Wood floor was replaced with 10, 15, and 20% MDF sanding dust (as a wood‐based panel waste), and the composites were manufactured by the extrusion method. Formaldehyde emission from WPCs was measured using two different methods: the desiccator method according to ISO 12460 and the flask method according to EN717‐3. Moreover, the physical and mechanical properties of the WPC samples were determined. The results indicated that the use of MDF sanding dust in formulation of WPCs leads to higher formaldehyde emission. The composites with

    Irreversible topological transition of a stretched superhelix: the interplay of chiralities

    Saeed Najafi
    Journal PapersSoft matter , Volume 15 , Issue 31, 2019 January , {Pages 6258-6262 }

    Abstract

    Helical complexes with certain intramolecular constraints on their topological state, exhibit nontrivial conformational changes in response to an external tension. We consider a generic right-handed helix and construct identical right and left-handed superhelixes. By using molecular dynamics simulations, we discover that under an external tension, the interplay between the helix chirality and the chirality of the superhelix leads to a fundamental topology transition of the stretched right-handed superhelix to its left-handed counterpart. We characterize and rationalize this irreversible phenomenon for a wide range of intramolecular angular stiffnesses and determine the associated phase diagram at different external loadings.

    Characterization of Polyurethane Wood Adhesive Prepared from Liquefied Sawdust by Ethylene Carbonate

    Soheyla Daneshvar, Rabi Behrooz, Saeed Kazemi Najafi, Gity Mir Mohamad Sadeghi
    Journal PapersBioResources , Volume 14 , Issue 1, 2019 January , {Pages 796-815 }

    Abstract

    Polyols, which are important compounds of polyurethane adhesives (PU), were prepared in this work from renewable sources. Beech wood sawdust was liquefied using ethylene carbonate as a new solvent and sulfuric acid as a catalyst in the two phases. The first phase of the liquefaction process was carried out at temperatures 110 to 160 C, and the catalyst content was studied in the second phase. The biopolyol was used for two types of polyurethane adhesive by blending two types of isocyanate, poly4, 4′-diphenyl methane diisocyanate (PMDI) and toluene diisocyanate (TDI), in different NCO/OH ratios for the preparation of polyurethane adhesives. Liquefaction temperature had a great influence on the characteristics of polyol such as acid and hyd

    EXPERIMENTAL ANALYSIS OF CONNECTIONS MADE WITH WOOD-BASED PANELS AND BRACKETS UNDER CYCLIC LOADING

    Seyed Mahdi MOUSAVI, Saeed Kazemi NAJAFI, Majid ELYASI
    Journal PapersSigma , Volume 10 , Issue 1, 2019 January , {Pages 09-Jan }

    Abstract

    The aim of this research was experimentally examination the behavior of metal brackets and wood-based panel connections under cyclic loading. For this purpose, different connections were manufactured using three types of brackets (4, 6 and 8 screws) and particleboard (PB) and medium density fiberboard (MDF). The connections were tested under monotonic and cyclic loading according to EN12512 standard and the mechanical properties such as maximum load, impairment of strength, equivalent viscous damping, ductility and the stiffness were determined. The results have shown that in both PB and MDF the brackets with 8 screws provide maximum strength. MDF and PB exhibited similar ductility and most of the connections exhibited viscous damping of le

    ASSESSMENT OF THE PROCESSING ROUGHNESS OF BLACK ALDER SURFACES

    Emilia Adela SALCA, Seyed Mahdi MOUSAVI, Saeed Kazemi NAJAFI, Majid ELYASI, Engin Derya GEZER, S?leyman KUŞTAŞ, Emir ERİŞİR, Esat G?M?ŞKAYA, Aydin DEMIR, Cenk DEMIRKIR, Ismail AYDIN, ?zlem BOZDOĞAN BAL?IK, Turgay ?ZDEMİR, Ayhan GEN?ER, Ahmet CAN, ?lk? Bur
    Journal PapersSigma , Volume 10 , Issue 1, 2019 January , {Pages 47-53 }

    Abstract

    The objective of the study was to compare the surface quality of the processed samples made of black alder (Alnus glutinosa L.) wood when using two milling cutters endowed with different cutting plates. Defect free samples provided by a local company were used. They were processed by longitudinal milling under laboratory conditions when applying various cutting schedules. The surface quality of the resulted samples was expressed by the most relevant processing roughness parameters. The roughness of the specimens was measured with the help of a specific profilometer device of FRT type with white light. The results of this study showed that the two milling cutters generated smooth surfaces with no or low fuzzy grain and such quality of the pr

    Negative Poisson Ratios in Wood and

    V Bucur, S Kazemi Najafi
    Journal PapersNondestructive Characterization of Materials XI: Proceedings of the 11th International Symposium Berlin, Germany, June 24–28, 2002 , Volume 6 , 2019 June 12, {Pages 47 }

    Abstract

    The Poisson ratios were determined with ultrasonic through transmission technique for Douglas–fir and particleboard. The hypothesis of the orthotropic anisotropy was accepted. In our experiments negative values were determined. These values have shown the structural anisotropy of wood and particleboard.

    دروس نیمسال جاری

    • دكتري
      آناليز و كنترل فرآيند ( واحد)
      دانشکده منابع طبیعی و علوم دریایی، گروه علوم و صنايع چوب و كاغذ
    • دكتري
      بازيافت كامپوزيت هاي ليگنوسلولزي ( واحد)
    • كارشناسي ارشد
      كامپوزيت چوب - پلاستيك ( واحد)

    دروس نیمسال قبل

    • دكتري
      روش هاي اندازه گيري در صنايع ليگنوسلولزي ( واحد)
      دانشکده منابع طبیعی و علوم دریایی، گروه علوم و صنايع چوب و كاغذ
    • كارشناسي ارشد
      آزمايشگاه فناوري چسب ( واحد)
    • كارشناسي ارشد
      فناوري چسب ( واحد)
    • 1393
      جزايري, رضا
      گرافيت اصلاح شده به عنوان افزودني چند منظوره در چسب اوره فرمالدهيد براي ساخت تخته فيبر نيمه سنگين (MDF)
    • 1395
      اقتدارنژاد, ندا
    • 1396
      نيكخواه شهميرزادي, ازاده
    • مدیر گروه علوم و صنایع چوب و کاغذ 1381-1388
    • مدیر گروه علوم و صنایع چوب و کاغذ 1391-1395
    • استاد نمونه دانشگاه تربیت مدرس در سال 1386
    • کتاب برگزیده سال جمهوری اسلامی ایران در سال 1396
    • نفر نخست کنکور سراسری کارشناسی ارشد رشته علوم و صنایع چوب و کاغذ در سال 1371

    مهم

    جدید

      اطلاعیه ای درج نشده است