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Tannin-Ca Complex as Green Thermal Stabilizer Additive for PVC: Viscoelastic Properties

Open Journal of Organic Polymer Materials 2015年第3期5卷 69-78页

作者： Hussein A. Shnawa yousef jahani Moayad N. Khalaf Abed Alamer H. Taobi Chemistry Department College of Science University of Bsarh Basrah Iraq Department of Plastics Faculty of Processing Iran Polymer and Petrochemical Institute Tehran Iran

This study investigated the viscoelastic and rheometeric properties of PVC stabilized with tannin-Ca complex as totally bio-based thermal stabilizer. Dynamic mechanical thermal analysis (DMTA) used to characterize the viscoelastic properties of PVC samples obtained by thermal mixing of PVC with three composition percentages (1.0, 2.0, and 3.0) part per hundred ratios (phr) of tannin-Ca complex with this polymer. The torque rheometery test used to monitor the effect of tannins derivative on the thermal stability and mixing properties of PVC formulations during samples processing. For that purpose, PVC sample with 2 phr commercial thermal stabilizer (Reapak B-NT/ 7060) was used for comparison and considered as reference samples. Before the glass transition temperature of PVC at 30°C - 60°C, the DMTA curves show that the values of storage modulus and tan delta of PVC samples stabilized with tannin derivative were very similar with those of PVC sample stabilized with commercial thermal stabilizer. The glass transition temperature (Tg) of PVC stabilized with commercial thermal stabilizer and with tannin-Ca complex occurred at about 76°C. In a sequence, after the glass transition region of PVC samples, the DMTA scans confirmed that the PVC samples with 2 phr tannin-Ca complex have relatively longer flowing stage which occurs at lower temperatures by 18°C per that of PVC sample stabilized with commercial stabilizer. Global results of the torque rheometery which have suitable plateau stages and the DMTA show that the processing thermal stability and thermal flexibility of PVC are clearly increased with the incorporation of tannin-Ca complex. All the PVC formulations with tannins-Ca complex show excellent viscoelastic properties which were found to be slightly best or much closed to those obtained for PVC stabilized with commercial thermal stabilization.

关键词： PVC Viscoelastic Properties Tannin-Ca Complex Thermal Stability Tg

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Efficient Thermal Stabilization of Polyvinyl Chloride with Tannin-Ca Complex as Bio-Based Thermal Stabilizer

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Materials Sciences and Applications 2015年第5期6卷 360-372页

作者： Hussein A. Shnawa Moayad N. Khalaf yousef jahani Abed Alameer H. Taobi Chemistry Department College of Science University of Basrah Basrah Iraq Department of Plastics Faculty of Processing Iran Polymer and Petrochemical Institute Tehran Iran

The potential use of tannin-Ca complex derived from tannins as bio-based thermal stabilizer and antioxidant additive for polyvinyl chloride (PVC) was investigated in this work. For this project, Reapak B-NT/7060 was applied as reference thermal stabilizer. Variable compositions: (1, 2, and 3) part per hundred ratio (phr) of tannin-Ca complex in the presence of 10 phr Dioctyl phthalate (DOP) as plasticizer in all PVC formulations were prepared by melt mixing by internal mixer at 165°C. Tannin-Ca complex was characterized by FT-IR spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX) analysis as well as by means of differential scanning calorimetry (DSC). The tannin derivative stabilization efficiency under inert atmosphere was determined by using thermogravimetric analysis (TGA). In addition, its thermal stabilization effect has been assessed in air as oxidizing atmosphere by DSC in dynamic conditions. According to TGA thermograms, the initial degradation temperature (Ti) and optimum degradation temperature (Top?) for the main degradation stage of PVC stabilized with this derivative were about 280°C and 310°C, respectively. While these were about 255°C and 293°C, respectively for PVC stabilized with commercial thermal stabilizer. Global results of TGA, DSC, SEM and EDX show that the tannin-Ca complex provides the best properties and results in stabilizing both against thermal degradation and thermal oxidation degradation of PVC.

关键词： PVC Natural Polyphenols Tannin-Calcium Complex Bio-Based Thermal Stabilizer

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挤压速度对搅拌摩擦反挤压法制备Cu-5%Ti_(2)SnC复合丝材性能的影响

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Transactions of Nonferrous Metals Society of China 2024年第3期34卷 935-951页

作者： Amirhossein jahani Hamed JAMSHIDI AVAL Mohammad RAJABI Roohollah JAMAATI Department of Materials Engineering Babol Noshirvani University of TechnologyShariati AvenueBabol 47148-71167Iran

对粉末冶金法制备的含5%(体积分数)Ti_(2)Sn CMAX相的初始复合材料进行搅拌摩擦反挤压(FSBE)处理,研究FSBE工艺的轴向横移速度对Cu-Ti_(2)Sn C复合线材显微组织、力学性能、电学性能和磨损性能的影响。结果表明,随着挤压速度的增加,显... 详细信息

对粉末冶金法制备的含5%(体积分数)Ti_(2)Sn CMAX相的初始复合材料进行搅拌摩擦反挤压(FSBE)处理,研究FSBE工艺的轴向横移速度对Cu-Ti_(2)Sn C复合线材显微组织、力学性能、电学性能和磨损性能的影响。结果表明,随着挤压速度的增加,显微组织中孪晶增多,Ti_(2)SnC颗粒细化,MAX相和Cu基体之间的界面结合改善。当转速为600r/min,轴向横移速度为25mm/min时,Cu-Ti_(2)SnC复合线材具有最大的硬度、屈服强度和极限抗拉强度,分别为HV 132.7、278.34MPa和485.15MPa,这是其更强的界面结合和更细的MAX相导致的。此外,当转速为600 r/min,轴向横移速度为25 mm/min时,Cu-Ti_(2)SnC复合丝的电导率最高,达到89.21%(IACS),磨损率最低,为0.0015 mg/m,这是其更大的晶粒尺寸、更强的界面结合与更低的密度导致的。

关键词：搅拌摩擦反挤压 Ti_(2)SnC MAX相铜基复合材料电导率

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Quantum Hall Effect and Different Zero-Energy Modes of Graphene

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Chinese Physics Letters 2011年第9期28卷 225-228页

作者： M.R.Setare D.jahani Department of Science Payame Noor UniversityBijarIran Young Researchers Club Kermanshah BranchIslamic Azad UniversityKermanshahIran

The effect of an inhomogeneous magnetic field,which varies inversely with distance on the ground state energy level of graphene,is *** analytically show that graphene under the influence of a magnetic field arising from a straight long current-carrying wire(proportional to the magnetic field from carbon nanotubes and nanowires)exhibits zero-energy solutions and find that contrary to the case of a uniform magnetic field for which the zero-energy modes show the localization of electrons entirely on just one sublattice corresponding to a single valley Hamiltonian,zero-energy solutions in this case reveal that the probabilities for the electrons to be on both sublattices,say A and B,are the same.

关键词： nanowires entirely field

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Regulation of neural stem cell fate decisions by mitochondrial dynamics

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Neural Regeneration Research 2018年第9期13卷 1548-1549页

作者： Matthew Laaper Arezu jahani-Asl Lady Davis Institute for Medical Research Jewish General Hospital Integrated Program in Neuroscience Mc Gill University Department of Oncology Faculty of MedicineMc Gill University Division of Experimental Medicine McGill University

Stem cells possess the ability to divide symmetrically or asymmet- rically to allow for maintenance of the stem cell pool or become committed progenitors and differentiate into various cell lineages. The unique self-renewal capabilities and pluripotency of stem cells are integral to tissue regeneration and repair （Oh et al., 2014）. Mul- tiple mechanisms including intracellular programs and extrinsic cues are reported to regulate neural stem cell （NSC） fate （Bond et al., 2015）. A recent study, published in Cell Stern Cell, identified a novel mechanism whereby mitochondrial dynamics drive NSC fate （Khacho et al., 2016）.

关键词： ATP Regulation of neural stem cell fate decisions by mitochondrial dynamics

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Restricted variation in data envelopment analysis with undesirable factors in nature

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International Journal of Biomathematics 2015年第3期8卷 125-134页

作者： Sohrab Kordrostami Alireza Amirteimoori Monireh jahani Sayyad Noveiri Department of Applied Mathematics Islamic Azad University Lahijan Branch Lahijan Iran Department of Applied Mathematics Islamic Azad University Rasht Branch Rasht Iran

In standard data envelopment analysis （DEA） models, inefficient decision-making units （DMUs） should change their inputs and outputs arbitrarily to meet the efficient frontier. However, in many real applications of DEA, because of some limitations in resources and DMU＇s ability, these variations cannot be made arbitrarily. Moreover, in some situations, undesirable factors with different disposability, strong or weak disposability, are found. In this paper, a DEA-based model is proposed to determine the relative efficiency of DMUs in such a restricted environment and in presence of undesirable factors. Indeed, variation levels of inputs and outputs are pre-defined and are considered to evaluate the performance of DMUs. Numerical examples are utilized to demonstrate the approach.

关键词： DEA efficiency undesirable factor restricted variation.

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Voltammetric determination of venlafaxine as an antidepressant drug employing Gd_2O_3 nanoparticles graphite screen printed electrode

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Journal of Rare Earths 2019年第3期37卷 322-328页

作者： Hadi Beitollahi Shohreh jahani Somayeh Tajik Mohammad Reza Ganjali Farnoush Faridbod Taher Alizadeh Environment Department Institute of Science and High Technology and Environmental Sciences Graduate University of Advanced Technology NanoBioElectrochemistry Research Center Bam University of Medical Sciences Center of Excellence in Electrochemistry School of Chemistry College of Science University of Tehran Biosensor Research Center Endocrinology & Metabolism Molecular-Cellular Sciences Institute Tehran University of Medical Sciences Department of Analytical Chemistry Faculty of Chemistry College of Science University of Tehran

Graphite screen printed electrode modified with Gd_2 O_3 nanoparticles(Gd_2 O_3/SPE) was developed for the determination of venlafaxine(VF). The Gd_2 O_3 nanoparticles were thoroughly characterized by scanning electron microscopy(SEM), transmission electron microscopy(TEM) and X-ray diffraction(XRD) analyses. To study the electrochemical behaviour of venlafaxine cyclic voltammetry(CV), chronoamperometry(CHA)and differential pulse voltammetry(DPV) were employed. These studies reveal that the oxidation of venlafaxine is facilitated at Gd_2 O_3/SPE. After optimization of analytical conditions, analysis of venlafaxine using the modified electrode in 0.1 mol/L PBS(pH 7.0) demonstrates that the peak currents corresponding to venlafaxine vary linearly with its concentration in the range of 5.0 ×10^(-6)-9.0 × 10^(-4) mol/L. The detection limit(S/N = 3) of 2.1 × 10^(-7) mol/L is obtained for venlafaxine using DPV. The prepared modified electrode benefits from advantages such as simple preparation method, high sensitivity and low detection ***, the evaluation of practical applicability of this proposed method is successful in the identification of venlafaxine in pharmaceutical formulations, urine and water samples.

关键词： Venlafaxine Gd2O3 nanoparticles Electrochemical techniques Screen printed electrode Rare earths

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Effect of extrusion speed on properties of Cu-5 vol.%TiSnC composite wire fabricated by friction stir back extrusion process

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Transactions of Nonferrous Metals Society of China 2023年

作者： Amirhossein jahani Hamed JAMSHIDI AVAL Mohammad RAJABI Roohollah JAMAATI Department of Materials Engineering， Babol Noshirvani University of Technology

The present work investigated the effect of axial traverse speed of friction stir back extrusion (FSBE) process on the microstructure， mechanical， electrical， and wear properties of Cu-Ti2SnC composite wire. The FSBE process was performed on the primary composite made by the powder metallurgy method with 5 vol.% of Ti2SnC MAX phase. The results showed that as the extrusion speed increased， the twins formed in the microstructure increased， the Ti2SnC particles became finer， and the interface of bonding of the MAX phase-Cu matrix improved. The Cu-Ti2SnC composite wire fabricated by the rotational speed of 600 rpm and axial traverse speed of 25 mm/min showed maximum hardness， yield strength， and ultimate tensile strength of 132.7 HV， 278.3， and 485.1 MPa， respectively. This finding was due to its stronger interfacial bonding and finer MAX phase particles. Besides， the larger grain size， better interface bonding， and lower porosity resulted in the highest electrical conductivity of 89.21% IASC and least wear rate of 0.0015 mg/m of Cu-Ti2SnC composite wire fabricated by 600 rpm rotational speed and 25 mm/min axial traverse speed.

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Facies, Sedimentary Environment and Sequence Stratigraphy of Dalan Formation in South Fars, Iran —(Qatar-South Fars Arch) Well ASL-A

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Open Journal of Geology 2016年第8期6卷 944-962页

作者： Nasser Rezavand Davood jahani Hossein Asilian Department of Geology North Tehran Branch Islamic Azad University Tehran Iran Department of Stratigraphy and Sedimentology NIOC Exploration Tehran Iran

Dalan Formation is one of the most important gas reservoirs of south and southwest Iran which it belongs to Dehram Group and its age is Middle to Late Permian. The Dalan formation is interpreted as reflecting a major tectono-eustatic event related to the onset of rapid thermal subsidence of the early Neo-Tethys passive margin in Arabia and Iran, and the drowning of its rift shoulders. The Dalan formation consists mainly of medium to thick-bedded oolitic to micritic shallow-marine carbonate, with intercalations of evaporates. This formation overlies the Faraghan formation and extends up into the Lower Triassic kangan formation. The current paper is focused on the facies, sedimentary environment and sequence Stratigraphy study of the Middle to Upper Permian Dalan formation in the West Assaluyeh gas field the subsurface section of well ASL-A. Based on microfacies analysis and significant founa and flora, nineteen major facies in five facies associations including Tidal flat (A), Lagoon (B), Shoal (C), Open marine (D) and Mid ramp (E) were recognized in the Dalan formation. Facies analysis and those comparisons with modern and ancient environments indicated that the Dalan formation was deposited inner to mid parts of a homoclinal ramp. The sequence stratigraphy studies on the Dalan formation in this gas field led to assessment of seven main sedimentary sequences of the third-order in the Assaluyeh field, well ASL-A. The boundary between the third-order sequences with the Faraghan formation and between the Nar and Upper Dalan members are Subaerial Unconformity (SU) and the boundaries between the third-order sequences with each other and also with the Kangan formation are Correlative Conformity (CC). The main diagenetic processes in this formation are dolomitization, dissolution, anhydritization, cementation and compaction which played a significant role in improving reservoir quality. The shoal ooid grainstone facies with intergranular and oomoldic porosity comprise the

关键词： Facies Sedimentary Environment Homoclinal Ramp Sequence Stratigraphy Dalan Formation

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Analysis of Sedimentary Environment and Sequence Stratigraphy of Middle-Late Permian Sediments in Coastal Fars, Iran (Zireh Gas Field, Well ZH-A)

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Open Journal of Geology 2016年第12期6卷 1539-1552页

The current paper is focused on the facies, sedimentary environment and depositional cycles study of the Middle-Late Permian sediments in the South Fars Zireh Gas Field, the subsurface section of well ZH-A. Four hundred thin-sections obtained from cores and cuttings were examined under standard petrographic microscope. For this study research, Corel Draw X6, Corel Photo-Paint, DN2 Microscopy Image Processing System, Scope Photo, Autodesk Map, Geocalc and Auto Cad 2014 were utilized. Based on microfacies analysis and significant founa and flora, fourteen major facies in four facies associations comprising tidal flat (A), lagoon (B), shoal (C) and open marine (D) identified in the well ZH-A. This formation was deposited in inner part of a homoclinal ramp. Based on depositional cycles, seven main 3rd order sequences were revealed in the Well ZH-A. The ooid grainstone facies with interparticle and oomoldic porosity has high reservoir potential. The diagenetic processes like dolomitization and dissolution have significant effect in the reservoir quality. Based on research results, a major framework can be weaved and used to correlate reservoir layering.

关键词： Middle-Late Permian Sediments Depositional Cycles Homoclinal Ramp

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