Engineering properties of alkali-activated natural pozzolan concrete

The development of alkali-activated binders with superior engineering properties and longer durability has emerged as an alternative to ordinary portland cement (OPC). It is possible to use alkali-activated natural pozzolans to prepare environmentally friendly geopolymer cement leading to the concept of sustainable development. This paper presents a summary of an experimental work that was conducted to determine mechanical strength, modulus of elasticity, ultrasonic pulse velocity, and shrinkage of different concrete mixtures prepared with alkali-activated Iranian natural pozzolans—namely Taftan andesite and Shahindej dacite, both with and without calcining. Test data were used for Taftan pozzolan to identify the effects of water-binder ratios (w/b) and curing conditions on the properties of the geopolymer concrete, whereas the influence of material composition was studied by activating Shahindej pozzolan both in the natural and calcined states. The results show that alkali-activated natural pozzolan (AANP) concretes develop moderate-to-high mechanical strength with a high modulus of elasticity and a shrinkage much lower than with OPC.

Effect of adding mineral additives to alkali-activated natural pozzolan paste

Natural pozzolans are raw materials from geological deposits with a range of chemical compositions that when combined with suitable alkali activators can be converted to geopolymer cement for concrete production. In this paper the concept of adding mineral additives to enhance the properties of geopolymer cement is introduced. Taftan andesite, a natural Iranian pozzolan, was used to study the effect of adding mineral additives such as kaolinite, lime and other calcined pozzolans on the compressive strength of geopolymer cement under both normal and autoclave curing. Scanning electron microscopy (SEM)/energy dispersive X-ray (EDX) was used to determine the composition of the gel phase in both alkali-activated Taftan pozzolan with and without mineral additions. The work has shown that deficiencies in SiO2, Al2O3 and CaO content in the raw natural pozzolan can be compensated for by adding mineral additives for enhanced properties.

Oxygen and Chloride Permeability of Alkali-Activated Natural Pozzolan Concrete

One of the important factors in the use of portland cement concrete is its durability, and most of the situations where durability is lacking have been identifi ed and strategies to manage durability have been implemented. Geopolymer concrete, made from an alkali-activated natural pozzolan (AANP), provides an important opportunity for the reduction of carbon dioxide (CO2) emissions associated with the manufacture of concrete but has a limited history of durability studies. Until its different properties are well understood there is no desire to adopt this new technology of unknown provenance by the concrete industry. This paper presents an experimental study of oxygen and chloride permeability of AANP concrete prepared by activating Taftan andesite and Shahindej dacite (Iranian natural pozzolans), with and without calcining, and the correlations between these properties and compressive strength. The results show that compared to ordinary portland cement (OPC) concrete, AANP concrete has lower oxygen permeability at later ages; but it shows moderate to high chloride ion penetrability.

Alkali-Activated Natural Pozzolan Concrete as New Construction Material

In the near future, geopolymers or alkali-activated cementitious materials will be used as new high-performance construction materials of low environmental impact with a reasonable cost. This material is a good candidate to partially replace ordinary portland cement (OPC) in concrete as a major construction material that plays an outstanding role in the construction industry of different structures. Geopolymer materials are inorganic polymers based on alumina and silica units; they are synthesized from a wide range of dehydroxylated alumina-silicate powders condensed with alkaline silicate in a highly alkaline environment. Geopolymeric materials can be produced from a wide range of alumina-silica, including natural products--such as natural pozzolan and metakaolin--or coproducts--such as fly ash (coal and lignite), oil fuel ash, blast furnace or steel slag, and silica fume--and provide a route toward sustainable development. Using lesser amounts of calcium-based raw materials, lower manufacturing temperature, and lower amounts of fuel result in reduced carbon emissions for geopolymer cement manufacture up to 22 to 72% in comparison with portland cement. A study has been done by the authors to investigate the intrinsic nature of different types of Iranian natural pozzolans to determine the activators and methods that could be used to produce a geopolymer concrete based on alkali-activated natural pozzolan (AANP) and optimize mixture design. The mechanical behavior and durability of these types of geopolymer concrete were investigated and compared with normal OPC concrete mixtures cast by the authors and also reported in the literature. This paper summarizes the main conclusions of the research regarding pozzolanic activity, activator properties, engineering and durability properties, applications and evaluation of carbon footprint, and cost for AANP concrete.

Photography, desire and resistance in the lives of women, following the 1979 revolution in Iran

In my last four years of PhD by practice at the Royal College of Art, I have conducted extensive research on archival photography including materials held at the Museum der Weltkulturen, Frankfurt am Main; the Institute for Iranian Contemporary Historical Studies (IICHS) , Tehran; and the International Institute of Social History (IISH), Amsterdam. My project started with the fortuitous encounter with a photograph taken by Iranian photographer Hengameh Golestan on the morning of March 8, 1979. The photograph shows women marching in the streets of Teheran in protest against the introduction of the compulsory Islamic dress code. In 1936 Reza Shah had decreed a ban on the headscarf as part oh his westernising project. Over forty years later following the 1979 Revolution, Ruhollah Khomeini reversed this decision by ordering that women should now cover their hair. This ‘found image’ presented me with a glimpse into the occulted history of my own country and the opportunity to advance towards a deeper learning and understanding of the event of March 8, 1979 a significant date in the history of feminism in Iran. In what follows I revisit the history of Iran since the 1979 revolution with a particular inflexion on the role women played in that history. However, as my project develops , I gradually move away from the socio-historical facts to investigate the legacy of the revolution on the representations of women in photography, film and literature as well as the creation of an imaginary space of self representation. To this end my writing moves constantly between the documentary, the analytical and the personal. In parallel I have made photographs and video works which are explorations of the veil as object of fascination and desire as well as symbol of repression.

Emerging borreliae – Expanding beyond Lyme borreliosis

Lyme borreliosis (or Lyme disease) has become a virtual household term to the exclusion of other forgotten, emerging or re-emerging borreliae. We review current knowledge regarding these other borreliae, exploring their ecology, epidemiology and pathological potential, for example, for the newly described B. mayonii. These bacteria range from tick-borne, relapsing fever-inducing strains detected in some soft ticks, such as B. mvumii, to those from bat ticks resembling B. turicatae. Some of these emerging pathogens remain unnamed, such as the borrelial strains found in South African penguins and some African cattle ticks. Others, such as B. microti and unnamed Iranian strains, have not been recognised through a lack of discriminatory diagnostic methods. Technical improvements in phylogenetic methods have allowed the differentiation of B. merionesi from other borrelial species that co-circulate in the same region. Furthermore, we discuss members that challenge the existing dogma that Lyme disease-inducing strains are transmitted by hard ticks, whilst the relapsing fever-inducing spirochaetes are transmitted by soft ticks. Controversially, the genus has now been split with Lyme disease-associated members being transferred to Borreliella, whilst the relapsing fever species retain the Borrelia genus name. It took some 60 years for the correlation with clinical presentations now known as Lyme borreliosis to be attributed to their spirochaetal cause. Many of the borreliae discussed here are currently considered exotic curiosities, whilst others, such as B. miyamotoi, are emerging as significant causes of morbidity. To elucidate their role as potential pathogenic agents, we first need to recognise their presence through suitable diagnostic approaches.

Empowering single mothers in Iran : Applying a problem-solving model in learning groups to develop participants' capacities to improve their lives

Since 2000, a problem-solving model has been taught to the Society for Protecting the Rights of the Child, and teachers and  students of social work in two universities in Iran. Since 2006, with the initiation of UNICEF, social workers, psychologists  and even some psychiatrists in Iran have been learning this model. In 2008, a group of researchers created an empowerment-oriented  psycho-social group and private intervention project to assess whether a group of Iranian single mothers could use this model, which was traditionally used by professionals only, to effectively and independently meet challenges in their own lives. Our results show that all women used the model effectively and, consequently, made more deliberate decisions to improve their life situations. Some of the women succeeded in finding a job and many improved their family relationships. This study suggests that empowerment-oriented social work can help many clients to achieve their goals, and that this psycho-social intervention project can be a useful model for social work in Iran and many other societies.

Cerâmica de Santo Antônio do Potengi: entre tradição e modernidade

In the Rio Grande do Norte, the craftsmanship is generating of economy, it involves a significant number of people and is diversified in its raw materials and particular type. As reference of the craft local, the ceramics supplied the primary necessities in the utilitarian domestic servants, acquired piety in the religious figures, were toy in infantile amusements and, finally, gained status of pure ornament. By its historical representation, the district of Santo Antônio do Potengi is considered the most important center of manufacture of craftpottery in the State. The work of the potters continues in that locality anchored between the familiar inheritance and the participation each more influential time of the public politics destined to the sector situation verified for visible alterations in the shape of the pottery from the decade of 1990 with the implantation of a cooperative destined to the collective production. We observe in this passage, that such actions in the measure where they objectify to structuralize conditions ideal to support the artisan making, do not benefit in significant way the social development them craftsmen. It is important not to lose of sight that exists some involved dimensions in this process and that these surpass the common interest for the object and the consequent economic connotation of its commercialization. They are knowledge that imply in the access to raw materials, in the peculiar of the formal aspects and productive methods, in the contextual relations organized to defend the survival of the activity

Personajes y Seres míticos Tairona

p. 108

La Rocca di Castiglione del Lago (PG) Campagna di scavo 2014

The archaeological study took into account a very important part of Castiglione del Lago urban unit, where the presence of stratification, probably from the Classical period, had been pointed out, on which military and religious units were over-lapped. More specifically, the area with a small church inside the arms courtyard of the castle, could have suggested the presence of archaeological realities,especially from the sporadic finding of Etruscan pottery. The archaeological investigation was first launched in the area of the small chapel, where at least two construction phases were highlighted, although with no appreciable result regarding Classical period phases. The excavation led to the discovery of underground structures, a number of Renaissance tombs placed around the church, and the identification of other structures related to military use over a cistern-well. At the end of the excavation, the structures were consolidated and protected before the backfilling; the materials recovered during the investigation have been registered at the Municipality of Castiglione del Lago, after bein examined by the Soprintendenza per i Beni Archeologi dell’Umbria and the Soprintendenza per i Beni Storico, Artistici ed Etnoantropologici dell’Umbria.

THE RELATIVE SIGNIFICANCE OF SYNTACTIC KNOWLEDGE AND VOCABULARY KNOWLEDGE IN SECOND LANGUAGE LISTENING COMPREHENSION

The main purpose of the current study was to examine the role of vocabulary knowledge (VK) and syntactic knowledge (SK) in L2 listening comprehension, as well as their relative significance. Unlike previous studies, the current project employed assessment tasks to measure aural and proceduralized VK and SK. In terms of VK, to avoid under-representing the construct, measures of both breadth (VB) and depth (VD) were included. Additionally, the current study examined the role of VK and SK by accounting for individual differences in two important cognitive factors in L2 listening: metacognitive knowledge (MK) and working memory (WM). Also, to explore the role of VK and SK more fully, the current study accounted for the negative impact of anxiety on WM and L2 listening. The study was carried out in an English as a Foreign Language (EFL) context, and participants were 263 Iranian learners at a wide range of English proficiency from lower-intermediate to advanced. Participants took a battery of ten linguistic, cognitive and affective measures. Then, the collected data were subjected to several preliminary analyses, but structural equation modeling (SEM) was then used as the primary analysis method to answer the study research questions. Results of the preliminary analyses revealed that MK and WM were significant predictors of L2 listening ability; thus, they were kept in the main SEM analyses. The significant role of WM was only observed when the negative effect of anxiety on WM was accounted for. Preliminary analyses also showed that VB and VD were not distinct measures of VK. However, the results also showed that if VB and VD were considered separate, VD was a better predictor of L2 listening success. The main analyses of the current study revealed a significant role for both VK and SK in explaining success in L2 listening comprehension, which differs from findings from previous empirical studies. However, SEM analysis did not reveal a statistically significant difference in terms of the predictive power of the two linguistic factors. Descriptive results of the SEM analysis, along with results from regression analysis, indicated to a more significant role for VK.

Salted-Fish industry in Roman Lusitania: Trade Memories between Oceanus and Mare Nostrum

Initiated by Augustus, Rome’s Atlantic policy seems to have been consolidated in the age of Claudius, with the acknowledgement of the economic potential offered by the Atlantic region. It is in this context that we must understand the development of the salted-fish industry in Lusitania. In the same geographical contexts, and in close relationship with fish-processing factories, are known about 20 pottery centres producing amphorae, located in the regions of Peniche, Sado and Tejo valleys, and the coasts of Alentejo and Algarve. This production extended in time beyond the end of the Western Roman Empire and up to the end of the 5th and 6th centuries, according to the archaeological data of some amphora kilns and fish-processing sites. The identification of Lusitanian amphorae in distant consuming centres and several shipwrecks in the Mediterranean basin confirm the long-distance commerce and the total integration of this “peripheral” region into the trade routes of the Roman Empire.

Identification, diversity and distribution patterns of fish larvae in Khark & Kharko Coralline Islands ecosystem – Persian Gulf, by GIS method

Khark & Kharko Islands are the last Northern point for fringing coral reefs in Iranian side of the Persian Gulf. These Coralline habitats are the Protected Area and Wildlife Refugees with the total area of 2400 ha which located in the territory of Bushehr Province. This research carried out during 2006-2007 with monthly sampling from 12 stations, which selected around Islands and inshore waters with maximum depth of 20 meter. Sampling was conducted using by Bongo-Net plankton sampler with 500μ of mesh size. Totally, 1808 specimen from 45 family fish larvae was identified in studied area, including: 21 coralline fish larva families and 24 shore fish larvae such as pelagic and demersal fishes which some of them known as indicator, sentinel or endemic species for coral reef ecosystems. The results was shown that coral reef diversity in coral reefs (Khark & Kharko Islands) is more than other habitats such as estuary and river mouth, creeks, mangrove forest sites, and off shore water of the Persian Gulf and Oman Sea Iranian side. Among Identified families, Clupeidae, Blenniidae, Sillaginidae, Atherinidae and Tripterygiidae; with more abundance were dominant families in studied area. The pick of fish larvae abundance family were estimated in spring. There were significant differences between seasonally abundance and sub areas, but there were not significant differences in diversity indexes between Khark and Kharko stations with coastal stations (p< 0.05). The mean abundance of fish larvae were estimated 18.7083 larvae under 10m² of sea surface, and the mean diversity indexes and evenness were estimated 0.7135 and 0.565342 consequently, that was showed the area is under ecological stress for fish larvae, and wasn’t stable. Therefore, from the ecological point of view, only some of the fish larvae groups as like Clupeidae were dominant. Thus, they were the main cause of the fish larvae abundance change in studied area. Due to geographical location of Khark and Kharko Islands and among the environmental parameters, Its seems that the condition of sea current is the main cause for present or absent and distribution patterns of fish larvae in area. Abundance of fish larvae in west of Islands was higher than eastern parts in the spring. But this condition will be reversed in eastern part of Island and several coastal stations, so that the Islands surrounding clock wise current to cause fish larvae distribution patterns.

A survey on prevalence rate of aflatoxigenic species of Aspergillus and residues of aflatoxins by ELISA method in cold-water cultural fish (rainbow trout) feeds in Tehran and West Azarbayjan provinces-Iran

Aflatoxins are one kind of fungal toxins produced by species of toxigenic Aspergillus (A. flavus and A. parasiticus) and in other words they are secondary metabolites which are considered as one of the threatening factors of food consumer's health. In this research 96 samples of cold-water cultural fish feed, rainbow trout, during the seasons of spring and summer of 2007 (every fifteenth of the month) were randomized (by simple and stratified random) to determine: 1. The prevalence rate of aflatoxigenic species of Aspergillus in stored feed of cold-water cultural fish in West Azarbayjan cultural fish farms in both seasons (spring and summer); 2. The residues of total aflatoxin in stored feed of fish in cultural fish farms of West Azarbayjan in both seasons by ELISA method; and 3. The residues of that toxin in feed produced in aquatic feed factories in Tehran and West Azarbyjan provinces with the same method. In order to study prevalence rate of toxigenic species of Aspergillus, pour-plate culture method by general medium such as Malt Extract Agar (M.E.A.) and Sabouraud-Dextrose Agar (S.D.A.) and by standard No.997 of Iranian Standard Institute were used. The produced colonies were examined microscopically. To determine the aflatoxins residues, ELISA method using Agra-Quant kit of Romer Lab company, were applied. The results of this survey indicated that only 8.3% of the samples were infected by A. flavus. A. parasiticus was not observed. There were no significant differences between the prevalence rate of AFT and seasons/months, either (P<0.05). Evaluating mean of aflatoxin rate showed that the rates of this variable are lower than the tolerance levels designated by the joint FAO/WHO expert committee (The mean of AFT in all data was lower than 11 ppb). Furthermore, mean of total AFT residues rates of stored feed of various cultural center of West Azarbayjan and Tehran factories were comparable in spring and summer, and no significant differences were observed (P<0.05). But there were significant differences between the total aflatoxin rates in the feed of West Azarbayjan factory and spring and summer (P<0.05), and AFT residues in spring (8.6 ppb) were higher than summer (6.1 ppb). Prevalence rates of AFT in Tehran feed factories (9.2 ppb) are higher than W. Azarbayjan (7.4 ppb). In other words, location was considered as a decisive factor in total AFT rates of samples. Moreover, the results indicated that there was significant difference between total aflatoxin rates of feed and cultural centers (P<0.05). The mean of AFT rates in embankment dam cultural fish farms (6.75 ppb) and multi-functions cultural fish farms (6.25 ppb) was higher than individual cultural pond (4.67 ppb). In conclusion, the finally results of this survey indicated that the lower rates of Aspergillus is not effective on the presence of total aflatoxin rates in trout feed. Due to low levels of aflatoxin rates (lower than 20 ppb), the produced feed of cold-cultural fishes, Rainbow Trout, in Tehran and West Azarbayjan provinces, in spring and summer of 2007, were safe and healthy both for fish and their consumers.

Survey of Amphiprion clarki & Amphiprion sebae populations in Persian Gulf by molecular genetics

Anemone fishes are a group of 28 species of coral reef fishes belonging to the family Pomacentridae, subfamily Amphiprioninae and all have an obligate symbiotic relationship with sea anemones. Two species of these small ornamental fishes have been identified in the Persian Gulf including Amphiprion clarkii and A. sebae. The phylogenetic relationship between Amphiprion species of the Persian Gulf was studied by collecting 15 samples from three Iranian islands, Larak, Farur and Kish. DNA was extracted from each sample and a part of mtDNA was amplified. Two pairs of primers were designed to amplify a final target of 400 by nested-PCR. Each amplicon was sequenced, aligned and genetic diversity among samples was investigated by phylogenetic analysis. Results show that there is no significant genetic variation among A. clarkii individuals; however, A. sebae individuals from Larak were different from other fishes of the same species. Most probably this is due to the ability of A. clarkii to be symbiotant with all 10 species of host sea anemones which enables it to spread its own population in the 3 islands. However, A. sebae is observed to be symbiotant only with one host in the sea, therefore, has one option that reduces its distribution.