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مرکز اطلاعات علمی SID1
اسکوپوس
مرکز اطلاعات علمی SID
ریسرچگیت
strs
Author(s): 

BRAUN D.

Issue Info: 
  • Year: 

    2002
  • Volume: 

    27
  • Issue: 

    -
  • Pages: 

    2171-2195
Measures: 
  • Citations: 

    413
  • Views: 

    20770
  • Downloads: 

    20300
Keywords: 
Abstract: 

Yearly Impact:

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Issue Info: 
  • Year: 

    2021
  • Volume: 

    39
  • Issue: 

    172
  • Pages: 

    120-135
Measures: 
  • Citations: 

    0
  • Views: 

    560
  • Downloads: 

    296
Abstract: 

Providing temporary shelter after major disasters is one of the major challenges for survivors and relief and reconstruction officials. In Iran, besides the distribution of tents, a common solution is to construct and deliver containers to the damaged areas. Following the 2017 earthquake in Kermanshah province, extensive damage was inflicted on urban and rural settlements, especially in the Dasht-e Zahab and Qasr-e-shirin districts. The high extent of the destruction, the proximity to the cold season, the rain, and the problems of living in emergency accommodation tents necessitated the acceleration of the provision of temporary housing and permanent shelter. The present article is a report of an action research project to find a different solution to this problem. Experience shows that accident survivors, especially in rural areas, provide shelter for their families by the locally available materials and technology, or the materials remained from the destroyed buildings. Aware of such a capacity, we tried to take a step towards providing temporary shelter by making maximum use of local materials and some non-local but inexpensive and affordable materials. For the first time, PVC pipes were used as the main structure of a temporary shelter. In the first phase, in December 2017, researchers visited the city of Sarpol-e Zahab and several villages in the region for six days in order to identify and evaluate the conditions of the region. Then, the design and execution of the first experimental sample of this structure called Kashaneh with dimensions of 2 × 3 meters was done in the Faculty of Architecture and Urban Planning of Shahid Beheshti University. During the execution, many points were identified and corrected, the strength of the structure was tested under gravity loading, and the structural calculations were performed using SAP2000 software. In the next step, the original sample with dimensions of 3 × 4 was built in the village of Kuik Aziz in the city of Sarpol-e Zahab. The willingness to participate among the residents and the positive feedback of the people towards the original sample indicated the success of this type of temporary shelter. Monitoring the samples, lower costs, speed of execution, participation of local labor force, ability to develop and attention to the psychological needs of the survivors in terms of similarity of the created space to a normal building, are among the advantages of this project.

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Issue Info: 
  • Year: 

    2006
  • Volume: 

    19
  • Issue: 

    3 (ISSUE NO. 83)
  • Pages: 

    175-184
Measures: 
  • Citations: 

    0
  • Views: 

    955
  • Downloads: 

    235
Keywords: 
Abstract: 

In this research two major methods for production of synthetic papers based on polyvinyl chloride (PVC) was studied.The effect of stretching and extraction on films based on neat PVC and PVC/NBR (butadiene acrylonitrile rubber) blends to obtain paper-like cellulosic property was analyzed. In the extraction method, PVC and PVC/NBR blends in the stretching method only the PVC/NBR blend were used. Sugar was used as extractable filler with solvent (water) to produce 35-40 percent volume porosity measured by Archimedes methods. Also, it was shown that by decreasing sugar particle size, average pore size is reduced as well. It was also shown that temperature effect on permeation is greater than acid concentration. This paper like substrates for writing with pencil and pen were assessed fair to poor. In the second part the effects of temperature, rate and extent of stretching on the ink dispersion as a criterion of surface roughness or irregularity compared to cellulose paper were investigated. The results indicate a direct correlation of ink dispersion increase with increase in temperature and the degree of stretching. But the increase in stretching rate would result in lesser dispersion at constant temperature and stretching rate.

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گارگاه ها آموزشی
Issue Info: 
  • Year: 

    2010
  • Volume: 

    19
  • Issue: 

    7 (121)
  • Pages: 

    483-489
Measures: 
  • Citations: 

    0
  • Views: 

    189008
  • Downloads: 

    89626
Abstract: 

Production and consumption of plastic materials have increased in recent decades. The increase in plastic production and consumption has been largely responsible for the increase in plastics waste production. The problem of plastics waste is quite important in terms of environmental sustainability and solid waste management. Plastics recycling require the separation of materials insofar as being almost pure. To achieve this goal in an economical way, technologies developed in mineral processing are of great help. Each method has certain capabilities and limitations. Instance separation of PET and PVC by gravity techniques is practically not applicable, due to slight differences in density. In this research, separation of PET and PVC by selective floatation was studied. The use of floatation for plastic separation is particularly challenging because of inherent hydrophobic nature of plastics surfaces. To separate PET and PVC, from the mixture of the two, by floatation should make one of them hydrophilic and wettable by water. This can be achieved by several methods among which the addition of a wetting agent that interacts with the surface layer is one of many techniques designed. In this study, tannic acid was employed as the depressant of PET. The results showed that, virgin materials can be separated with 99.62% efficiency. In the case of post-consumer PET and PVC, 88.40% separation efficiency was achieved at optimum conditions. Also, in virgin and postconsumer materials, difference in the contact angles of PET and PVC increased as tannic acid dosage increased. Besides, the results indicated that the pH of the conditioning step is vital with respect to separation efficiency. 

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Issue Info: 
  • Year: 

    2004
  • Volume: 

    17
  • Issue: 

    2 (ISSUE NO. 70)
  • Pages: 

    71-77
Measures: 
  • Citations: 

    0
  • Views: 

    1341
  • Downloads: 

    294
Keywords: 
Abstract: 

PVC is one of the most important and widely used plastics in polymer industries. Blending is an effective method to improve the undesirable properties of PVC such as stiffness and brittleness. One of the most important blends of PVC is its mechanical mixing with nitrile rubber, but it should be reminded that despite of expensiveness, it has not desirable tear strength. In this work, SBR was added to the blend of PVC/NBR with the purpose to achieve better tear strength with lower cost. The effect of adding SBR and also mixing factors on mechanical properties of ternary blend were investigated using experimental design, i.e. Taguchi method. With the aid of replacing 7% by weight of NBR by SBR in PVC/NBR-SBR ternary blend the tear strength increased twice to the initial value.

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Journal: 

PETROLEUM RESEARCH

Issue Info: 
  • Year: 

    2008
  • Volume: 

    18
  • Issue: 

    57
  • Pages: 

    52-61
Measures: 
  • Citations: 

    1
  • Views: 

    2052
  • Downloads: 

    520
Abstract: 

In this research blends of two samples of Acrylonitrile-Butadiene-Styrene (ABS) with three samples of Poly (vinyl chloride) (PVC) were prepared via melt processing and their physical, mechanical and fire properties were investigated. It was found that properties of blends were significantly depends on blend composition and PVC compound types, but the properties of blends containing different types of ABS similar results were seen.On blending of ABS with soft PVC compound, impact strength and melt flow index (MFI) of ABS were increased, however, tensile and flexural strength were decreased. In contrast, blending of ABS with rigid PVC improved its fire retardancy and some mechanical properties but decreased its MFI and impact strength.

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strs
Author(s): 

Hamedi G. H.

Issue Info: 
  • Year: 

    2019
  • Volume: 

    32
  • Issue: 

    2
  • Pages: 

    1-16
Measures: 
  • Citations: 

    0
  • Views: 

    327
  • Downloads: 

    207
Abstract: 

Moisture damage is defined as loss of strength and durability of asphalt mixtures in the presence of water. In this study, the effect of Polyvinyl Chloride (PVC) polymer was evaluated as an asphalt binder modifier on the moisture damage of HMA. Indirect tensile test in dry and 1, 3 & 5 freeze-thaw conditions and thermodynamic method according to the measurements of surface free energy components of aggregates and asphalt binders were used for evaluating the effect of polymeric materials. The results of this study show that using of PVC cause an increase in the strength of the asphalt mixture against the moisture damage. Also, PVC increased the free energy of cohesion and reduced the debonding energy. These cause decreased in the rate of the moisture damage of asphalt mixtures.

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Issue Info: 
  • Year: 

    2019
  • Volume: 

    11
  • Issue: 

    1
  • Pages: 

    13-25
Measures: 
  • Citations: 

    0
  • Views: 

    399
  • Downloads: 

    194
Abstract: 

In this research, the effect of multiwall carbon nanotubes (MWCNTs) on the performance of polyvinyl chloride (PVC) membrane in the filtration of humic acid solution was investigated. The FESEM results showed that the number of surface pores in nanocomposite membranes is more than that of PVC membrane. The tensile strength and abrasion resistance of membranes increased with increasing MWCNTs up to 053 wt. %. It was also observed that water flux of membrane containing 053 wt. % MWCNTs increases up to 48457 L/m2h. The decrease of water contact angle from 88568 for PVC membrane to 70528 for 053 wt. % MWCNTs membrane showed that the hydrophilicity of membranes increases with increasing MWCNTs. It was also found that the rejection of humic acid solution with MWCNTs membranes is more than that of PVC membrane. The analysis of fouling mechanism of membranes revealed that the cake formation model is dominant mechanism for all membranes and cake filtration-complete blockage model fits the volume-time data.

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Issue Info: 
  • Year: 

    2014
  • Volume: 

    13
  • Issue: 

    75
  • Pages: 

    78-86
Measures: 
  • Citations: 

    0
  • Views: 

    1864
  • Downloads: 

    428
Abstract: 

Polyvinyl chloride was discovered in the late nineteenth century, but until 1920s, it was not commercially produced and marketed. This polymer has high consumption rate in the world after polyethylene and it can be rigid or flexible, opaque, transparent or colored and insulating or conducting. Depending on the type of polymer, polyvinyl chloride is produced by various methods, including suspension, emulsion, solution, micro suspension. Suspension polymerization of monomers is used in most cases like suspension of particles in water. This article introduces the chemistry of the polymerization reaction and after presentation of different production methods, economic cost evaluation of the unit is discussed. In order to economic estimation of the plant, obtaining input and output flow rates and calculated size of all equipment are required. Therefore, to obtain the mass flow rates, the process simulation is carried out. In this study, production process simulation is performed by ASPEN POLYMER PLUS software. Then final equipments. prices and economic estimation of plant are calculated by taking equipments. size in to consideration. Results show that for a PVC production unit with a capacity of 45, 000 tons per year, the fixed capital and operating capital are equivalent to 18, 275, 000 and 2, 742, 000 dollars, respectively.

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Issue Info: 
  • Year: 

    2005
  • Volume: 

    14
  • Issue: 

    9 (63)
  • Pages: 

    769-773
Measures: 
  • Citations: 

    0
  • Views: 

    144556
  • Downloads: 

    179924
Abstract: 

The thermal and mechanical properties of plasticized PVC with epoxidized soya bean oil(PVC-ESBO) are studied. The repulsive interactions are used to explain the effect of epoxidization on the modulus of PVC with ESBO and plasticizer. The glass transition temperature of PVC is a linear function of the epoxidization of ESBO plasticizer. The activation energies of stabilized PVC/ESBO are also influenced by dehydrorochlorination reaction and HCl evolution. Addition of ESBO improves thermal behaviour of PVC. The higher activation energies of Ca-Zn, Ba-Zn stabilizers are responsible for the stability of PVC-ESBO. The epoxidization level of ESBO also improves the mechanical properties and thermal stability of PVC.

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