Static And Dynamic Behavior Of Pile Groups

Pile group foundations are often used to support heavy structures. The capacity of the pile foundation to resist static and dynamic loads depends on the behavior of the piles which, in turn, is a product of pile-soil-pile interaction.;Dynamic analysis of pile groups is very recent and rather complex while corresponding experimental data are limited.;Field dynamic experiments and limited static tests with a large group of 102 piles are described and results are presented in order to verify the linear theories accounting for pile-soil-pile interaction.;The experimental data for vertical and horizontal excitation are compared with the theoretical predictions made on the basis of different approaches that account for the group effect, namely; static interaction factors, dynamic interaction factors, complete dynamic solution, direct static analysis and the equivalent pier. The comparison suggests that dynamic analytical techniques are able to predict the main features of dynamic behavior of pile groups, but tend to overestimate damping, i.e., underestimate the response. In addition to the difficulty involved in calculating the static interaction factors for large groups, the approach may underestimate the stiffness and does not yield any estimate of group geometric damping.;A method is formulated which avoids the use of the interaction factors while remaining simple and is computationally very efficient, facilitating a fast inexpensive computer analysis of very large pile groups. The method presented allows for an arbitrary soil profile, pile type and configuration, evaluates group stiffness, forces on individual piles and material damping making it suitable for static and low frequency dynamic loading. The direct analysis calculates the vertical, horizontal and rocking response; its results agree very well with those of field experiments and other direct methods available

In Absence of a Hero Figure and an Ideology: Understanding New Political Imaginaries and Practices among Revolutionary Youth in Egypt

One of the challenges in analyzing youth who participated in the recent Arab uprisings relates to explaining and understanding their revolutionary practices. Adopting a leaderless and cross-ideological form of mobilization, youth during the eighteen days of the Egyptian uprising managed to practice inclusion by uniting a diverse group of Egyptians. After toppling Mubarak, the revolutionary youth, however, did not present themselves as aiming to seize power, a defining feature of revolutions at least until the 1970s. To understand the meaning of these new cross-ideological and leaderless forms of mobilization, I suggest understanding youth within their time and space. Drawing on Alain Badiou and his conception of the intervallic period and the rebirth of history through the Arab revolts, this article highlights important differences among this generation in their conception of doing politics. More specifically, this paper focuses on the changed meaning of the hero figure, highlighting the importance of inclusionary politics. It will suggest that since the 2011 revolutionary event, a shift away from traditional politics based on a leader and an ideology is being contested for a more inclusionary politics as desired by the younger generation in Egypt

Liquid Phase Nano Metal Catalyzed Dechlorination of Chlorinated Organic Compounds

1,2-Dichloroethane (1,2-DCA) is among the most prevalent groundwater chlorinated organic compounds (COCs) found at hazardous sites throughout the world. Given its pervasive contamination and adverse health effects, there is considerable interest in developing novel remediation technologies for successfully treating 1,2-DCA along with other COCs from water sources. Chemical reduction by nano zero valent iron (monometallic (nZVI) or bimetallic (Pd-nZVI)) has proven to be a successful field applicable technology, yet it has failed in degrading such a recalcitrant compound as 1,2-DCA. In this study, the development of a field applicable nano metal based technology capable of degrading 1,2-DCA was carried out. For the first and the second studies, the feasibility of catalyzed dechlorination of 1,2-DCA using borohydride as a Hydrogen (H2) source over nano palladium (nPd) and nano copper (nCu) in the liquid phase at room temperature was investigated. Complete removal of 1,2-DCAin a matter of days or hours was achieved by either nPd or nCu particles coupled with borohydride. The novel dechlorination system produced mainly ethane as the dechlorination byproduct, without formation of toxic chlorinated intermediates. This phase also examined the influence of different experimental parameters including: metal loading, 1,2-DCA loading, nanoparticle synthesis parameters and groundwater solutes on the dechlorination kinetics. It was found that experimental parameters affect the chemical composition as well as oxidation state of the nanoparticles, which controls the dechlorination reaction rate. For the third study, the efficiency of the developed novel technology, along with nZVI, Pd-nZVI, and nZVI-dithionite in remediating a suite of COCs, including 1,2-DCA, in a groundwater sample from an industrial site in Australia was assessed. nZVI, Pd-nZVI, and nZVI-dithionite were able to break down COCs with the exception of 1,2-DCA. nZVI-dithionite was able to breakdown about 20% of 1,2-DCA. nPd or nCu coupled with borohydride degraded 55% and 94%, respectively, of 1,2-DCA along with complete removal of all other COCs. The presence of groundwater solutes was found to adversely affect dechlorination efficiency of the treatments. Overall, this thesis presents a novel nano metal based remediation technology capable of reducing 1,2-DCA. The results suggest that the developed nano metal based technology can be an effective remediation approach for multi-COCs contaminated groundwater depending upon site conditions

Youth and the 25th Revolution in Egypt: agents of change and its multiple meanings

The 25th of January 2011 marks an important date for Egypt and the world. Not only did former President Hosni Mubarak who has ruled Egypt for 30 years step down, but the youth who were once conceived as incapable of change were hailed as those who brought about this transformation. Yet how could the youth organize and bring about such a change that was not only unthinkable for many, but not one who took to the streets on the 25th imagined they could topple Hosni Mubarak in 18 short days. In this thesis I thus ask: 1) how have youth been deployed before and after the 25th of January Revolution as agents of change, 2) what kind of transformations are youth imagining for Egypt. Several events since the 1990s contributed to sharpening the youth consciousness culminating in taking the streets on January, 25th demanding â change, freedom, and social justice. I argue that, especially since the 1990s, a series of events and protests contributed to the formation of this generational consciousness which materialized on January 25th when thousands of mainly youth went on the streets to demand change. During the 1990s the adoption of neoliberal strategies pushed the state to minimize its role and promote civil society activities many of which focused on development. Many members of the organization were mainly focused on helping the poor (as a religious responsibility) without demanding social justice on challenging their own privileges. Secondly, a number of protests in the 2000 onwards were ushered by different protest movements such as Kefaya and the 6th of April youth movement. As national strategies failed to employ the majority of the youth, they became a burden on society. Not being able to afford a good education, employment, or marriage, Egyptian youth transformed from being the hope of the country in the 1950\u27s to a serious social problem n the by the 1980\u27s (Ibrahim, 2008). This affected youth\u27s everyday interactions as they were financially dependent on their families, while their leisure time activities were seen as dangerous or morally corrupt potentially leading to criminal activities, drug abuse, and immorality. To channel particular categories of youth, NGOs offered the path of civic participation as a means to harness their energies toward development, while maintaining structurally the status quo of society, economy and polity. By taking the streets on January the 25th, Egyptian youth for a short period transformed from being the problem to being the hope of the country. Through the governance of Tahrir square, Egyptian youth proved their eagerness to change and with the ousting of Mubarak they were celebrated as heroes. Tahrir Square thus played a major role in reviving the youth and in transforming them from the problem to the hope of the country. Class, gender, and religion shaped the imagery of which young person can bring about change. A masculine, upper middle class man was mainly attached to the new young person that can change Egypt. However, now, a clash of generations is clearly taking place in which the emerging youth generation fights for political inclusion. Different events such as the protests on Mohamed Mahmoud Street (just off of Tahrir Square) and in front of the cabinet, or the parliamentary elections, are just some examples of power negotiations between the old and new generations. By developing a generational consciousness, there is hope that youth can bring about change, however, depending on their age, class, religion, and gender, their experiences differ giving them different outlooks on the future and also a potential source of division among this generation. My research project focused on youth who both demonstrated and protested during the Revolution and those who did not. In addition, I analyzed the national Al Ahram newspaper in the years 2000, 2004, 2008, 2010, and 2011and attended many public talks in order to unveil how youth were conceived as the problem before the Revolution and transformed into the hope of the country during the 18 days of the uprising. With a new generational consciousness, many young people are hopeful for a better future, however, their inexperience in politics makes it a difficult task to achieve

Monotonic and Cyclic Behaviour of Steel Fibre-Reinforced and FRP-Steel Fibre-Reinforced Helical Pulldown Micropiles

Helical piles are a deep foundation system that can be used to support pipelines, telecommunication and transmission towers, and low- and medium-rise buildings. Advantages of helical piles include: short installation time with minimal noise and vibration levels; can be installed with ease in limited accessibility site; and onsite quality control by measurement of installation torque. The main objective of the current research is to assess the performance of steel fibre-reinforced helical pulldown micropiles (RHPM), and fibre-reinforced polymer-steel fibre- reinforced pulldown micropiles (FRP-RHPM) under axial and lateral monotonic and cyclic loading conditions. The research methodology involved conducting full scale field testing on: one plain helical pile, 12 RHPM and 12 FRP-RHPM. Piles were subjected to axial static and one-way cyclic loading, and lateral static and two-way cyclic loading. The axial test results were then used to calibrate a three-dimensional finite element model. To calibrate the lateral test results, moment-rigidity curves for the tested piles were generated through three-dimensional finite element models. Along with test results, these curves were used to calibrate a finite difference model. The experimental investigation under axial loads shows that these pile systems behave as composite pile systems. The grout shaft significantly improves the helical pile axial performance. Cyclic loads resulted in degradation of the shaft resistance, however, resulted in an improvement of the lead section resistance. The overall pile cyclic response was found to stabilize after a few cycles of loading. Finally, the cyclic loading was found to improve the axial capacity of these systems. The experimental investigation under lateral loads shows that the grout shaft and/or the FRP sleeve significantly improve the plain helical pile lateral performance and ductility. Two-way cyclic loading resulted in overall degradation in pile stiffness and capacity. A design procedure for FRP-RHPM and RHPM under axial compression loading conditions is presented. For the lateral direction, a series of design charts that can be used in conjunction with available numerical programs to design such systems are provided. In general, the RHPM and FRP-RHPM are viable foundation options for axial and lateral monotonic and cyclic loading applications

Towards a frame of reference (Heuristic Guide) for the development of informal markets in Egyptian rural

Street markets represent an important element in forming the economy of countries, especially those that occupy a large proportion of their area in rural areas, Egypt is one of those countries. We find that the rural community needs outlets to display their micro-products, whether agricultural or not agriculture, such as the handicraft products that are popular with tourists. Informal street markets have arisen due to their lack of need for government authorities to interfere in their establishment, and due to the belief of the rural people that these markets do not need permits. The spread of this type of market in rural areas reflects the inability of the authorities to contain, legalize them. The research dealt with the theoretical and analytical approach, as it presented the planning, design, legal and control problems that characterize these markets, and focus on the expected returns from legalizing these markets and preventing the emergence of new ones. We addressed the considerations that must be present in the market location, and patterns of its urban formation, highlighting the role of the main elements that must be available in the market and their functional relations with each other. In order to ensure good coordination and harmony between the main elements of the market, it was necessary to focus on the design considerations for the planning of the markets. By addressing the markets elements, a set of recommendations were reached, which are the nucleus for a guideline to solve the problems of informal markets in Egyptian countryside

Fluorescent reporters for functional analysis in rice leaves.

Fluorescent reporters have facilitated non-invasive imaging in multiple plant species and thus allowed the analysis of processes ranging from gene expression and protein localization to cellular patterning. However, in rice, a globally important crop and model species, there are relatively few reports of fluorescent proteins being used in leaves. Fluorescence imaging is particularly difficult in the rice leaf blade, likely due to a high degree of light scattering in this tissue. To address this, we investigated approaches to improve deep imaging in mature rice leaf blades. We found that ClearSee treatment, which has previously been used to visualize fluorescent reporters in whole tissues of plants, led to improved imaging in rice. Removing epidermal and subtending mesophyll cell layers was faster than ClearSee and also reduced light scattering such that imaging of fluorescent proteins in deeper leaf layers was possible. To expand the range of fluorescent proteins suitable for imaging in rice, we screened twelve whose spectral profiles spanned most of the visible spectrum. This identified five proteins (mTurquoise2, mNeonGreen, mClover3, mKOκ, and tdTomato) that are robustly expressed and detectable in mesophyll cells of stably transformed plants. Using microparticle bombardment, we show that mTurquoise2 and mNeonGreen can be used for simultaneous multicolor imaging of different subcellular compartments. Overall, we conclude that mTurquoise2, mNeonGreen, mClover3, mKOκ, and tdTomato are suitable for high-resolution live imaging of rice leaves, both after transient and stable transformation. Along with the rapid microparticle bombardment method, which allows transient transformation of major cell types in the leaf blade, these fluorescent reporters should greatly facilitate the analysis of gene expression and cell biology in rice

Roles of cofactors and chromatin accessibility in Hox protein target specificity.

BACKGROUND: The regulation of specific target genes by transcription factors is central to our understanding of gene network control in developmental and physiological processes yet how target specificity is achieved is still poorly understood. This is well illustrated by the Hox family of transcription factors as their limited in vitro DNA-binding specificity contrasts with their clear in vivo functional specificity. RESULTS: We generated genome-wide binding profiles for three Hox proteins, Ubx, Abd-A and Abd-B, following transient expression in Drosophila Kc167 cells, revealing clear target specificity and a striking influence of chromatin accessibility. In the absence of the TALE class homeodomain cofactors Exd and Hth, Ubx and Abd-A bind at a very similar set of target sites in accessible chromatin, whereas Abd-B binds at an additional specific set of targets. Provision of Hox cofactors Exd and Hth considerably modifies the Ubx genome-wide binding profile enabling Ubx to bind at an additional novel set of targets. Both the Abd-B specific targets and the cofactor-dependent Ubx targets are in chromatin that is relatively DNase1 inaccessible prior to the expression of Hox proteins/Hox cofactors. CONCLUSIONS: Our experiments demonstrate a strong role for chromatin accessibility in Hox protein binding and suggest that Hox protein competition with nucleosomes has a major role in Hox protein target specificity in vivo.This work was supported by University of Malaya High Impact Research Grant UM-HIR UM.C/625/HIR/MOHE/CHAN-08 from the Ministry of Higher Education Malaysia.This is the final version of the article. It was first available from BioMed Central via http://dx.doi.org/10.1186/s13072-015-0049-

Superabsorbent composites based on rice husk for agricultural applications: Swelling behavior, biodegradability in soil and drought alleviation

Abstract Low-cost composites with high water absorption capacity were prepared by free radical copolymerization of acrylic acid (AA), acrylamide (AM) and gelatin in aqueous media using N,N' methylene bis-acrylamide (MBA) as crosslinker, potassium persulfate (KPS) as initiator and rice husk (RH) as a filler. The composites were characterized by Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The effects of different parameters such as the alkaline treatment on the rice husk, the media pH and salinity and the composition of the composites on their water absorption capacity were investigated. The water retention and biodegradation tests in soil were also carried out. The optimized composite containing treated RH showed a maximum water uptake value of 825 g∙g−1 in distilled water and good resistance in saline solutions and in the pH range of 6–10. Positive effects on the soil water retention were obtained after 30 days samples of soil containing 1 wt% of superabsorbent composites still contained about 7% of the initial absorbed water. Growth attributes, photosynthetic pigments and nodulation traits of droughted peanut were improved by 60 kg∙ha−1 dosage of SAC. On the basis of the good results of water retention and controlled biodegradability in the soil, the developed composites have the potential to be used in agriculture for better water management, with relevant environmental benefits