Evidence-based spatial intervention for regeneration of deteriorating urban areas, a case of study from Tehran, Iran

Throughout the urban development process over the last seven decades in Tehran, the capital city of Iran, many self-generated neighbourhoods have developed in which the majority of the residents are low-income families. On one hand, the main spatial attribute of these deprived neighbourhoods is spatial isolation from the surrounding, more affluent areas, which is accompanied by inadequate urban infrastructure and a lack of accessibility and permeability. On the other hand, the Tehran City Revitalisation Organisation - the governmental sector which is in charge of the deprived areas - is incapable of conducting urban regenerations without investment from the private sector, and is seeking methods to create ‘socio-economic stimulant zones’ to attract private sector participation in regeneration programmes. In this regard, this research investigates the notion of ‘spatial isolation’ which in return causes socio-economic isolation as highlighted in the literature. The research suggests that in order to develop feasible regeneration programmes, which can meet the interest of both people and government, and release the deprived area from isolation both spatially and socio-economically, the regeneration plans should focus on public open space developments as ‘socio-economic stimulant zones’. With regard to this idea, the research highlights the street as a ‘social arena’ – not arteries or thoroughfares – as the type of public open space in which its development could not only release the deprived areas from spatial isolation, but could also direct more pedestrian movement to and through the deprived neighbourhoods, making more opportunities for the creation of socio-economic interactions. In this respect, the theory of ‘natural movement’ and theories and literature of ‘integrated public open spaces’ form the theoretical framework of the research to support this idea. For further investigation, two case studies, one as the deprived area and one as the control area, have been chosen, and the spatial pattern of the city and the two cases have been analysed in regard to the notion of ‘spatial isolation’ through Space Syntax using Depthmap software and GIS. Also, the correlation between the distribution pattern of commercial land uses and syntactic measures across the city of Tehran is investigated to identify the potential streets in which to create commercial opportunities. Afterwards, in order to study the street life and the variety of activities the streets can afford, a few locally integrated streets in the deprived case have been chosen. At this stage, nineteen behaviours have been observed and classified in five major classes including the necessary, social, optional, hazardous, and occasional activities, and the correlation with syntactic measures are studied. Moreover, the methods of developing a route filtering system and a transformability index for identifying the most suitable streets for the creation of a pedestrian friendly network are discussed, using an example of a deprived area, integrating it with the surrounding urban fabric to create the ‘socio-economic stimulant zones’. The results show that by identifying the underlying spatial pattern of the urban fabric, it is possible to release the deprived areas from its spatial isolation through developing a street network without causing urban fragmentation. This approach could also form a cost-effective basis for developing a pedestrian friendly street network as one of the ‘socio-economic stimulant zones’, which the Tehran City Revitalisation Organisation is looking for; the type of streets that not only support the necessary activities and transportation, but could also facilitate socio-economic interaction

Semi-Quantitative Dermal Exposure Assessment of Lead with DREAM Model in a Lead Mine in Iran

Occupational exposure to toxic substances occurs in a variety of ways. The DREAM model is suggested for assessing skin exposure using preset values. The purpose of this study is to investigate the exposure of lead in workers at a mine lead using the DREAM model. This research was done in several steps. First, collect information about people and the work environment. Then design the model in Excel2016 by the authors. This research was descriptive-analytic research and included 46 miners. The DREAM model has a total of 33 variables included. In the DREAM model, exposure assessment was performed for 9 body parts at task level 2. The DREAM model was completed for 5 jobs. Jobs were in the lab, tunnel-74, tunnel-34, entrance to the tunnel and flotation workshop. The results were calculated for each of the 9 parts of the site for propagation, transfer, deposition, and potential and actual exposures, and eventually total exposures. The DREAM model, in comparison with similar methods, estimates the skin exposure level in a semi-quantitative fashion. This method has been used to estimate skin exposure in a variety of industries. This method was used to assess the skin exposure of workers in a mine, which resulted in training workers and providing personal protective equipment appropriate to the environment

Group extensions and marginal series of pair of groups

In this article, using the concept of generalized Baer-invariant of a pair of groups, we establish some related isomorphisms between lower marginal quotient pairs of groups, which are generalized versions of some isomorphisms of Stallings. We also derive a result for the pair $(\mathcal{V}.\mathcal{W}, \mathcal{X})$ to be an ultra Hall pair for special varieties of groups. This result generalizes that of Fung in 1977, which has roots in Philip Hall’s criterion on nilpotency

Group extensions and marginal series of pair of groups

In this article, using the concept of generalized Baer-invariant of a pair of groups, we establish some related isomorphisms between lower marginal quotient pairs of groups, which are generalized versions of some isomorphisms of Stallings. We also derive a result for the pair $(\mathcal{V}.\mathcal{W}, \mathcal{X})$ to be an ultra Hall pair for special varieties of groups. This result generalizes that of Fung in 1977, which has roots in Philip Hall’s criterion on nilpotency

Effect of Ramadan fasting on physiologic myopia

زمینه و هدف: نزدیک بینی از شایع ترین نوع عیوب انکساری چشم است. با توجه به اینکه تغذیه از جمله عوامل متعددی است که در ایجاد میوپی دخیل میباشد . این مطالعه با هدف بررسی میزان تاثیر روزه داری بر مقدار میوپی در طی ماه مبارک رمضان انجام شد. روش بررسی: مطالعه به صورت توصیفی – تحلیلی بر روی 122 چشم از 61 نفر انجام شد. جامعه مورد بررسی افراد میوپ مذکر با درجه نزدیک بینی 50/0- تا 00/8- دیوپتر در سنین 50-22 سال بودند. قبل از ماه مبارک رمضان کلیه افراد تحت معاینه کامل چشمی قرار گرفتند و عیب انکساری آنها با روش Cycloplegic refraction اندازه گیری شد. پس از پایان ماه مبارک رمضان در افرادی که توفیق روزه داری به مدت حداقل 29 روز را داشتند مجدداً معاینات چشمی شامل حدت بینایی و عیب انکساری و معاینه با Slit lamp و فوندوسکپی انجام شد و نتایج قبل و بعد از روزه داری با استفاده از آزمون t زوج مورد بررسی و تحلیل قرار گرفت. یافته ها: میانگین سنی بیماران 24/11±20/31 (دامنه 50-22) سال بود. حدت بینایی تمام بیماران 20/20 بود. میانگین عیب انکساری افراد قبل و پس از روزه داری به ترتیب 80/2±21/3- و 00/3±16/3- دیوپتر به دست آمد (05/0P>). نتیجه گیری: روزه داری در افراد مذکر بالای 22 سال موجب تغییر مقدار میوپی نمی شود

Alcohol-assisted versus Mechanical Epithelium Removal in Photorefractive Keratectomy

Purpose: To compare the outcomes and complications of alcohol-assisted versus mechanical corneal epithelial debridement for photorefractive keratectomy (PRK). Methods: This randomized controlled trial included 1,250 eyes of 625 patients undergoing PRK for correction of myopia and myopic astigmatism. Each patient was randomly assigned to alcohol-assisted or mechanical epithelial removal. Results: A total of 658 eyes underwent alcohol-assisted epithelial removal while the epithelium was removed mechanically in 592 eyes. Mean spherical equivalent was ‑4.37}2.3 D in the alcohol group and ‑3.8}1.3 D in the mechanical group (P = 0.78). There was no significant difference in postoperative pain between the study groups (P = 0.22). Uncorrected visual acuity ≥ 20/20 and ≥ 20/40 was achieved in 90.9% versus 93.4% (P = 0.08), and 98.9% versus 99.5% (P = 0.36) of eyes in the alcohol and mechanical groups, respectively. Final refractive error within 1D of emmetropia was achieved in 90% versus 92.2% of eyes in the alcohol and mechanical groups, respectively (P = 0.23). Alcohol-assisted debridement required less time than mechanical debridement (96±18 vs. 118±26 seconds, P=0.035). There was no significant difference between the two groups in terms of early and late postoperative complications. Conclusion: Alcohol-assisted and mechanical epithelium removal are comparable in terms of efficacy and side effects. The method of epithelial debridement in PRK may be left to the surgeon′s choice

A Comparative Evaluation of TiO 2

The most important parameters affecting the efficiency of catalysts for the oxidation of the surrounding materials are considered to be the thickness and uniformity of the catalyst layer. The present method for the determination of thickness used in most studies is the analysis of cross-sectional pictures from SEM imaging. This method, however, has several restrictions. This study proposes a feasible and simple method for evaluating the optimal thickness and uniformity using UVA light transmitted through the samples. Three techniques for catalyst deposition have been investigated in this study using UVA light transmitted through the samples and by measuring the photocatalytic activity. These methods include lowering, dip coating, and spraying, which showed coefficients of variation for the coated catalyst weight of 28.4%, 13.6%, and 3.24%, respectively. The samples from the lowering, dip coating, and spraying techniques showed UVA transmissions of 95.02%, 68.8%, and 15.6%, respectively. The spraying technique displayed the lowest values for both. The estimated removal efficiencies (%RE/mgcm−2) for lowering, dip coating, and spraying were 18.42, 16.84, and 24.15, respectively. Using these analyses it was determined that the spraying technique yielded the best photocatalytic oxidation performance of the three techniques studied