New-town programs and housing schemes: a case of mutual path dependence in Iran

This paper advances the concept of mutual path dependence by investigating the new-town and low-income housing initiatives in Iran. Seventeen new towns have been established in the country. Many of them have additionally become major sites for Iran’s low-income housing scheme. The study employs a flexible approach to policy research to assess the two related programs. According to its findings, the initiatives have been able to offer less expensive means to homeownership on a large scale, with the more successful new-town cases acting as dormitory communities next to large cities. Yet, the new towns and their housing projects exhibit various infrastructure and service shortcomings as well as a failure to link to regional or national plans concerned with territorial balance, industrial development, and employment. More importantly, as the main source of finance in the new towns is opaque land sales, it has given impetus to property speculation and corruption. Despite these major issues, the current policy is to continue both initiatives. The paper thus suggests that Iran’s new towns and housing schemes exhibit related path dependencies. The continuation and progression of each program depend on its previous path as well as that of the other initiative, rather than sound policy responses to the prevailing circumstances and their challenges.

     

Transfer function‐based Bayesian damage detection under seismic excitation

Transfer function (TF) data are recognized as diagnostic features in damage detection procedure. The objective of this paper is to present a damage detection method in Bayesian paradigm based on TF data due to ground excitation. The measured seismic responses of the structure in the frequency domain are adopted to obtain displacement TFs and the structural natural frequencies are identified from observed TFs. The derived features are utilized for Bayesian structural damage detection. In addition, the challenging issue of underlying flexible soil in real cases has been addressed. The proposed technique is applied to a numerical shear frame to evaluate the capability of the method. An experimental study on a six‐story steel building has been validated to demonstrate the capability of the method for damage detection purpose. The results of studied cases indicated that the proposed method is capable of identifying the location and the severity of damage precisely.     

Peculiar effect of polyethylene glycol in comparison with triethyl citrate or diethyl phthalate on properties of ethyl cellulose microcapsules containing propranolol hydrochloride in process of emulsion-solvent evaporation

Plasticizers play a crucial role in various process of microencapsulation. In this study, the effect of incorporation of plasticizer in process of emulsion solvent evaporation was investigated on properties of ethyl cellulose (EC) microcapsules containing propranolol hydrochloride. The effect of plasticizer type and concentration were investigated on characteristics of microcapsules prepared from different viscosity grades of EC. Product yield, encapsulation efficiency, mean particle size, shape, surface characteristics, solid state of drug, and drug release profiles were evaluated. Product yield and encapsulation efficiency were not dependent on plasticizer type and concentration. However, encapsulation efficiency decreased with increase in EC viscosity grade in the most of the cases. The mean particle size was in the range of 724–797?μm and was not dependent on plasticizer type. Microcapsules formed in the presence of PEG had a very smooth surface with few pores. XRD and DSC studies revealed a reduction of drug crystallinity after microencapsulation especially in presence of PEG. The results showed that the presence of TEC and DEP with different concentrations had no marked effect on drug release from microcapsules containing different viscosity grades of EC. This was not the case when PEG was used, and despite its water solubility it reduced the drug release rate noticeably. The reduction in the drug release in the presence of PEG was concentration-dependent. The use of PEG as a plasticizer in process of emulsion solvent evaporation highly improved the EC microcapsule structure and retarded the drug release rate and therefore is recommended.     

Synthesis and properties of new poly(amide‐imide)s based on 1,3‐bis[4,4'‐(trimellitimido) phenoxy] propane and aromatic diamines

Six new poly(amide‐imide)s 8a–f containing trimethylene moiety in the main chain were synthesized by the polycondensation reactions of 1,3‐bis[4,4'‐(trimellitimido) phenoxy] propane 6 with six different aromatic diamines 7a–f in a medium constituting N‐methyl‐2‐pyrrolidone, triphenylphosphite, CaCl₂, and pyridine as condensing agents. The polycondensation reaction produced a series of novel poly(amide‐imide)s 8a–f in high yields with inherent viscosities between 0.35 and 0.63 dL/g. The resulting poly(amide‐imide)s were characterized by elemental analysis, viscosity measurements, thermal gravimetric analysis (TGA and DTG), solubility tests, and FTIR spectroscopy. 1,3‐Bis[4,4'‐(trimellitimido) phenoxy] propane 6 as a new monomer containing trimethylene moiety was synthesized using a three‐step reaction. At first 1,3‐bis[4,4'‐nitrophenoxy] propane 3 was prepared by the reaction of 4‐nitrophenol 1 with 1,3‐dibromo propane 2 in DMF solution . Then, dinitro 3 was reduced to 1,3‐bis[4,4'‐aminophenoxy] propane 4 by using a solution of sodium sulfite in ethanol. Finally, 1,3‐bis[4,4'‐(trimellitimido) phenoxy] propane 6 was prepared by the reaction of one equivalent diamine 4 with two equivalents of trimellitic anhydride 5 in a mixture of acetic acid‐pyridine (3 : 2). © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Mechanical Properties of Artificial Stones Produced from Sludge of Stone-Cutting Factories (SSCF): The Effects of Nano-fillers (<Emphasis Type=Italic>a</Emphasis>TiO<Subscript>2</Subscript> and ZnO Nanoparticles)

The aim of this study is to present the advantages of artificial stone production from the sludge of stone cutting factories (SSCFs), which is a self-cleaning and low-cost process, in Lorestan province, Iran. The basic formulation of artificial stone is the sludge stone: 50 % of the weight (wt.%) of sludge stone is cement. 12 wt.%, 25 wt.%, and 7 wt.% of the cement consists of unsaturated polyester resin liquid (UPR), water, and, filler respectively. The filler itself is made up of micro-silica and different amounts of anatase TiO₂-NP and ZnO-NP. Nanoparticles lead to hydrophobicity, the analysis of oil stains, the elimination of bad odor, the sterilization and self-cleaning of artificial stone. The production of artificial stone via this method is pressure-resistant, highly flexible, resistant to freezing and scrapes, lightweight, capable of being cut and formed with a low thickness, and self-cleaning compared to the natural stone.     

Maximum allowable fouling detection in industrial fired heater furnaces

Journal of Mechanical Science and Technology - Fouling is one the most serious problems in refineries that can have irreparable consequences. In this study, fouling detection inside the tubes in...