Seismic response evaluation of concentrically rocking zipper braced frames

Nasim Irani Sarand,Abdolrahim Jalali 국제구조공학회 2020 Structural Engineering and Mechanics, An Int'l Jou Vol.73 No.3

In this study an innovative rocking zipper braced frame (RZBF) is proposed to overcome the deficiencies of common concentrically braced frames. RZBF is an improved rocking concentrically braced frame which is based on combination of rocking behavior and zipper columns. The base rocking joints and post-tensioned bars provide rocking response and restoring force, respectively. Also, zipper columns distribute the unbalance force over the frame height and reduce the damage concentration. To evaluate seismic performance of RZBF, a comparison study is carried out considering concentrically braced frame, zipper braced frame, rocking concentrically braced frame and RZBF. Thereby, a suite of non-linear time history analyses had been performed on four different types of archetypes with four, six, eight, ten and twelve stories. Frames were designed and non-linear time history analyses were conducted in OpenSees. To compare the seismic behavior of the archetypes, roof drifts, residual roof drifts, story drifts, the forces of first and top story braces, PT bars forces, column uplift and base shears were taken in to consideration. Results illustrate that using RZBF, can reduce the damage due to reduced residual drifts. Zipper columns enhance the seismic performance of rocking systems. As the number of stories increase in the RZBF systems, larger top story braces were needed. So the RZBF system is applicable on low and midrise buildings.

Comparing Different Classifiers and Features for Electroencephalography-Based Product Preference Recognition

Nasim Alnuman,Samira Al-Nasser,Omar Yasin 한국지능시스템학회 2024 INTERNATIONAL JOURNAL of FUZZY LOGIC and INTELLIGE Vol.24 No.3

Impact of Nitrogen and Plant Growth Promoting Rhizobacteria on Yield and Yield Components of Sunflower in a Glasshouse Environment

Nasim, Wajid,Bano, Asghari 한국작물학회 2012 Journal of crop science and biotechnology Vol.15 No.4

The effects of Nitrogen (N) and Plant Growth Promoting Rhizobacteria (PGPR) on growth and development of sunflower (Helianthus annuus L. var. Hysun-33) grown in the greenhouse under a natural environment were studied. The N-use efficiency of a sunflower crop grown under three N rates ($N_1=0kg\;ha^{-1}$, $N_2=120kg\;ha^{-1}$, and $N_3=240kg\;ha^{-1}$) and three PGPR levels ($R_1=0kg\;ha^{-1}$, $R_2=30kg\;ha^{-1}$, and $R_3=60kg\;ha^{-1}$) were investigated. The maximum amount of N resulted in higher total dry matter production per plant and the effect was prominent from 34 days after sowing (DAS). Seed yields differed significantly among different sunflower crops especially at limiting N supply, with significant shifts according to the N level. N uptake was an important parameter for yield at all N rates. The 240 kg N $ha^{-1}$ treatments provided the maximum yield, while the oil contents in these treatments of higher yield showed a lower oil content (%). Harvest index was also significantly correlated to yield across N rates; however, its importance depended much on environmental conditions as well. It can be inferred from the study that sunflower crop is well-supplied with respect to growth, development, yield and yield components, to enhance N efficiency and depends very much on the N supply. All the parameters gave maximum results with the increment of N while PGPR regimes had no prominent impact on the sunflower crop, the target environment, and the target yield level grown under a specified controlled glasshouse environment.

A visible-light-active BiFeO3/ZnS nanocomposite for photocatalytic conversion of greenhouse gases

Nasim Bagvand,Shahram Sharifnia,Elham Karamian 한국화학공학회 2018 Korean Journal of Chemical Engineering Vol.35 No.8

Given the changes in environmental conditions in the world, photocatalytic conversion of greenhouse gases is of great interest today. Our aim was to increase the photocatalytic efficiency of BiFeO3/ZnS (p-n heterojunction photocatalyst) by varying the molar ratio of ZnS to perovskite structure of BiFeO3 using hydrothermal synthesis. The results of X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), FT-IR spectroscopy showed the small crystal size and suitable distribution of ZnS particles on the BiFeO3 structure. The results of UV-visible, and photoluminescence (PL) spectroscopy analyses showed the good behavior of p-n heterostructure in absorption of visible light and lowering electron-hole recombination. The best visible light photocatalytic efficiency of CO2 reduction, 24.8%, was obtained by an equimolar ratio of BiFeO3/ZnS.

Formation of few-layer graphene flake structures from graphite particles during thin film coating using dry spray deposition method

Nasim, M.N.E.A.A.,Chun, D.M. Elsevier Sequoia 2017 THIN SOLID FILMS - Vol.622 No.-

This work demonstrates the formation of few-layer graphene flake structures directly from graphite particles. A nano-particle deposition system, which is a dry spray deposition method generally used for deposition of metals and ceramics, has been introduced to deposit graphite particles at room temperature. In this study, graphite powder was deposited on a Cu substrate without using binders and the deposited thin film was characterized. The deposited thin film contained few-layer graphene flake structures, as observed using field effect scanning electron microscopy and confirmed using X-ray diffraction, Raman spectroscopy and field emission transmission electron microscopy. We also suggested the critical impact velocity for deposition of few-layer graphene flake structured thin film and a mechanism for forming few-layer graphene flake structures during thin film preparation. The suggested mechanism was interlayer separation of micron-sized graphite particles and fragmentation of particles into small pieces during deposition due to the impact of graphite particles on the substrate.

Promoting Fairness in EFL Writing Assessment: Are There Any Effects of the Writers’ Awareness of the Rating Criteria?

Nasim Ghanbari 아시아테플 2019 The Journal of Asia TEFL Vol.16 No.2

Cyclic variations of gonad development of an air-breathing fish, Channa striata in the lentic and lotic environments

Nasim Al Mahmud,Hassan Md. Hafizur Rahman,Golam Mohammod Mostakim,Mohd. Golam Quader Khan,Md. Shahjahan,Nahid Sultana Lucky,M. Sadiqul Islam 한국수산과학회 2016 Fisheries and Aquatic Sciences Vol.19 No.1

The study was conducted to know the cyclic changes in gonadal maturation and to investigate the developmental stages of oocytes and testicular germ cells of an air-breathing fish, Channa striata. Fish were sampled monthly from lentic and lotic environments of three geographical locations of Bangladesh from December to November and the histological analysis of their gonad was done to evaluate the objectives. The highest mean GSI was 5.95 ± 0.20 for female in July and 0.14 ± 0.01 for male also in July showing that the gonadal development reached its peak during this month. The highest mean oocyte diameter was 1257.50 ± 24.17 μm observed in July implying that the oocyte reached maturity in this month. Histological study of ovary revealed the evidence of early yolk granule stage and late yolk granule stage from April to July. In case of male four stages of spermatogenesis were distinguished and spermatozoa were highly abundant in June and July. So the monthly pooled values of GSI and the analysis of gonadal histology indicated that the peak breeding season of C. striata occurred in July in the lentic and lotic environments. Samples collected from lentic and lotic habitats are suggestive of no difference in the development of the gonad. The results of the present study will be useful for selective breeding programme, conservation and sustainable fishery management of C. striata in its natural habitat.

Study on the effects of processing parameters on the CVD alumina coating

Nasim Chenari,Mansour Soltanieh,Arash Yazdani 한양대학교 세라믹연구소 2013 Journal of Ceramic Processing Research Vol.14 No.6

The CVD alumina coatings were deposited on carbide cutting tools using gas mixtures of H2, CO2 and AlCl3 at the temperatures between 960-1000 o C, one atmosphere pressure and for different gas flows of H2, CO2. The AlCl3 gas is produced in a generator by passing the HCl gas through the mechanically worked aluminium granules. In a simulated laboratory setup it was found that the reactivity of aluminium granules with HCl was increased drastically. Thickness measurements showed that by using worked granules, the alumina thickness for the same conditions increases from 0.75 to 3 µm. Moreover, it was found that with increasing the coating temperature and flow of gases, deposition rate was increased. Calculations showed that the process is far from the equilibrium condition. It was found that the reaction is kinetically mass transfer controlled in the boundary layer. The activation energy of the process was equal to 207.02 Kj/mol.

Effect of using recycled coarse aggregate and recycled asphalt pavement on the properties of pervious concrete

Nasim K. Shatarat,Hasan N. Katkhuda,Khaled H. Hyari,Ibrahim Asi 국제구조공학회 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.67 No.3

This paper presents the results of a study that investigated the influence of using recycled coarse aggregate (RCA) and recycled asphalt pavement (RAP) on the properties of pervious concrete (PC). The natural aggregate (NA) was replaced by RCA and RAP in the PC with replacement levels of 0%, 20%, 40%, 60% and 80% by the total weight of NA, respectively. In addition to incorporating RAP and RCA in the same mixes with replacement levels of: (1) 20% RAP and 80% RCA; (2) 60% RAP and 40% RCA; and (3) 80% RAP and 20% RCA. Water permeability, thermal conductivity, density, porosity, void content, and compressive, splitting tensile and flexural strengths were studied in this paper. The results showed that using RCA, RAP, and (RAP-RCA) enhanced the properties of PC in general and improved the mechanical properties significantly in particular. The optimum mix was reported to be the 60% RAP and 40% RCA. Accordingly, the RAP has the potential to be used in PC in order to reduce the negative impact of RAP on the human health and environment.

The effect of chemical modification of SiO2 nanoparticles on the nanofiltration characteristics of polyamide membrane

Nasim Rakhshan,Majid Pakizeh 한국화학공학회 2015 Korean Journal of Chemical Engineering Vol.32 No.12

This study presents the synthesis and characterization of oleic acid (OA)-modified silica/polyamide (PA) nanocomposite membranes. The thin film composite (TFC) polyamide was prepared with M-phenylendiamine (MPD) and trimesoyl chloride (TMC) via interfacial polymerization over porous polysulfone. Five different thin film nanocomposite (TFN) membranes were fabricated by dispersing OA-modified silica nanoparticles in TMC solution. Chemical and thermal properties, surface morphology, roughness, film thickness and hydrophilicity of synthesized membranes were characterized by ATR-IR, TGA, FESEM, AFM, TEM and contact angle analysis. The results showed that incorporating OA-modified silica into thin film layer improved chemical and physical properties of nanocomposite membranes. The effects of modification of nano silica on pure water flux and MgSO4 rejection were investigated. OAmodified silica/PA membranes showed higher pure water flux in comparison with neat polyamide TFC membrane but lower than unmodified silica/PA membrane; while significant increase in salt rejection was exhibited for OA-modified silica/PA membranes. The maximum rejection for OA-modified and unmodified nanocomposite membrane was obtained about 98.7% and 95.2%, respectively.