Fresh and hardened properties of self-compacting concrete containing of cement kiln dust

There are many wastes form the cement industry among them cement kiln dust (CKD). This residue is obtained after the process of burning the raw materials of cement in the rotary kiln where it is suctioned by fans during the clinker exit of the rotary kiln. Cement dust is a major environmental and economic problem in terms of high quality air pollution ranging from (20-100) microns and the proportions of chlorides, sulphates, alkali and lime living in a way that threatens the general health of human, as well as water pollution if the waste is discharged by rivers and waterways. This investigation’s main objective is to present the potential of using CKD as a cement replacement in self-compacting concrete (SCC). Eight mixes incorporating CKD with partial cement replacement of 0%, 5%, 10%, 20%, 30%, 40%, 50% and 75% in addition to control mix were investigated. The properties of all mixture were determined. Based on the experimental program results, it was found that SCC mixture incorporating 5% to 10% of CKD was almost similar to that of control mixture. The workability of SCC concrete decreased as CKD replacement increased. This established benefits of substituting cement by CKD to make SCC

Modelling Risk on the Egyptian Stock Market: Evidence from a Markov-Regime Switching GARCH Process.

This research aims at evaluating among market risk measures to equity exposures on the Egyptian stock market, while utilising a variety of parametric and non-parametric methods to estimating volatility dynamics. Historical Simulation, EWMA (RiskMetrics), GARCH, GJR-GARCH, and Markov-Regime switching GARCH models are empirically estimated. Value at Risk and Conditional Value at Risk measures are backtested in order to evaluate among the alternative models. Results indicate the superiority of asymmetric GARCH models when combined with a Markov-Regime switching process in quantifying market risk - as is evident from the results of the backtests - which have been performed in accordance with the current regulatory demands. Implications are important to regulators and practitioners

Modelling Risk on the Egyptian Stock Market: Evidence from a Markov-Regime Switching GARCH Process.

This research aims at evaluating among market risk measures to equity exposures on the Egyptian stock market, while utilising a variety of parametric and non-parametric methods to estimating volatility dynamics. Historical Simulation, EWMA (RiskMetrics), GARCH, GJR-GARCH, and Markov-Regime switching GARCH models are empirically estimated. Value at Risk and Conditional Value at Risk measures are backtested in order to evaluate among the alternative models. Results indicate the superiority of asymmetric GARCH models when combined with a Markov-Regime switching process in quantifying market risk - as is evident from the results of the backtests - which have been performed in accordance with the current regulatory demands. Implications are important to regulators and practitioners

Ancestral Dependence on Breast Stemness and Nucleotide Excision Repair in Breast Cancer Stem Cells in Novel Human Model Systems

Precocious puberty, measured by thelarche or menarche, is a well-established breast cancer risk factor. Using a unique and patented tissue engineering system we established cell lines from 48 primary cultures of normal breast tissue from reduction mammoplasties and used them as an in vitro model of thelarche, quantifying episphere formation and ductal differentiation. Differential ductal formation was observed based on ancestry. In light of African American (AA) precocious thelarche both in vivo and as we observed in vitro, we hypothesized that AA women would exhibit an increased proportion of breast stem cells, with greater potency for differentiation. Five AA cell lines and five European-derived white (EW) cell lines were analyzed. AA cell lines had significantly higher percentages of breast stem cells and these stem cells were more potent than those from EW cell lines, indicating innate differences in stem cells might be responsible for ancestral differences in thelarche. We adapted our tissue engineering system for xenoestrogenic assay development. The formation of epispheres was dose-responsive with estradiol and bisphenol A. Development of a new assay is crucial for banning consumer chemicals that cause cancer related changes in breast development. We then investigated breast cancer cell lines for the role of Nucleotide Excision Repair (NER) in disease progression. Late stage breast cancer cell lines (pre- or post-treatment) manifested significantly higher NER capacity than stage I breast cancer or reduction cell lines. Increased NER capacity may be responsible for chemotherapeutic resistance, consequential of tumor progression. We hypothesized that the driver of higher repair capacity was due to the cancer stem cell populations within these cell lines. Cancer stem cells were flow sorted from breast cancer-derived cell lines and subjected to the functional Unscheduled DNA Synthesis (UDS) assay to assess NER capacity. Cancer stem cells had increased NER capacity compared with non-stem cells from the same cell lines. These data are consistent with breast cancer stem cells driving the increased NER capacity in late stage breast tumors. Developing therapies specific to the breast cancer stem cell compartment, albeit an elusive target, may provide a new treatment modality for resistant, late stage breast tumors

A Comparison Between International and US Graduate Students’ Attitudes and Experiences Using Massive Open Online Courses (MOOCs)

Massive Open Online Courses (MOOCs) have affected the pattern of learning in the last few years. Many studies have been conducted to investigate MOOCs\u27 impact on the educational field. In this study, the researcher will compare international and US graduate students\u27 attitudes and experiences when they use MOOCs as a resource for learning. The study used a mixed-method design to collect the data. Quantitative data was compiled by using 79 responses for an online survey, and qualitative data was gathered by 10 semi-structured interviews. Participants in the study were graduate students at Rochester Institute of Technology. They were divided into two groups, international graduate students and US graduate students, who represented the study population. The study finds some similarities and differences between International and US graduate students. One of the obvious similarities is that students in both groups use MOOCs to supplement their learning. Moreover, MOOCs helped students to increase their knowledge in other fields and become more confident to learn new things. There are differences in ways of using MOOCs between international and US graduate students. One of these differences is that international students may use MOOCs to enhance their English proficiency and familiarize themselves to the US educational system before coming to the US. To interpret the high ratio of the drop outs in MOOCs, the researcher believes that students are not aware of the reality of the expression drop out in MOOCs or they just ignore participating

Lower Cretaceous Ratawi Formation Saudi Arabia-Kuwait Partitioned Neutral Zone : deposition, diagenesis and petroleum geology in the framework of sequence stratigraphy.

Available from British Library Document Supply Centre-DSC:DXN050491 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

Design Configurations and Operating Limitations of an Oscillating Heat Pipe

Passive and compact heat dissipation systems are and will remain vital for the successful operation of modern electronic systems. Oscillating heat pipes (OHPs) have been a part of this research area since their inception due to their ability to passively manage high heat fluxes. In the current investigation, different designs of tubular, flat plate, and multiple layer oscillating heat pipes are studied by using different operating parameters to investigate the operating limitations of each design. Furthermore, selective laser melting was demonstrated as a new OHP manufacturing technique and was used to create a compact multiple layer flat plate OHP. A 7-turn tubular oscillating heat pipe (T-OHP) was created and tested experimentally with three working fluids (water, acetone, and n-pentane) and different orientations (horizontal, vertical top heating, and vertical bottom heating). For vertical, T-OHP was tested with the condenser at 0°, 45° and 90° bend angle from the y-axis (achieved by bending the OHP in the adiabatic) in both bottom and top heating modes. The results show that T-OHP thermal performance depends on the bend angle, working fluid, and orientation. Another design of L-shape closed loop square microchannel (750 x 750 microns) copper heat pipe was fabricated from copper to create a thermal connector with thermal resistance \u3c 0.09 ˚C/W for electronic boards. The TC-OHP was able to manage heat rates up to 250 W. A laser powder bed fusion (L-PBF) additive manufacturing (AM) method was employed for fabricating a multi-layered, Ti-6Al-4V oscillating heat pipe (ML-OHP). The 50.8 x 38.1 x 15.75 mm3 ML-OHP consisted of four inter-connected layers of circular mini-channels, as well an integrated, hermetic-grade fill port. A series of experiments were conducted to characterize the ML-OHP thermal performance by varying power input (up to 50 W), working fluid (water, acetone, NovecTM 7200, and n-pentane), and operating orientation (vertical bottom-heating, horizontal, and vertical top-heating). The ML-OHP was found to operate effectively for all working fluids and orientations investigated, demonstrating that the OHP can function in a multi-layered form, and further indicating that one can ‘stack’ multiple, interconnected OHPs within flat media for increased thermal management