Assessing the Ageing Impact on Fatigue Life of Asphalt Concrete

The fatigue life of asphalt concrete is often related to environmental condition, loading condition, ageing, material composition and  properties. This work investigates the influence of short and long term ageing of laboratory beam specimens, asphalt content, and testing temperature on fatigue life of asphalt concrete wearing course. Slab samples of (30 x 40x 6) cm have been prepared, beam specimens of (40x 5x 6) cm were cut from the asphalt concrete slab samples. Beam specimens were tested for fatigue life under the influence of three levels of micro strain (250, 400, and [3]750) at (5, 20, and 30) °C before and after practicing long-term aging. It was observed that the fatigue life decreases by (85 and 97) %, (87.5 and 97.4) %, (71.4 and 95.2) % after increasing the applied microstrain from (250 to 400 and 750) μƐ for control mixture and for mixtures subjected to short-and long-term ageing processes respectively. The fatigue life increases by (142.8 and 257.1) %, (34.4 and 57.8) % and (10 and 30) % when the asphalt content increases from (4.4 to 4.9 and 5.4) % for specimens practicing the applied microstrain of (250, 400 and 750) μƐ respectively. It was concluded that the fatigue life increases by a range of (two to fifteen) folds when the testing temperature increases from (5 to 20 and 30)°C respectively

Titanocene anticancer complexes and their binding mode of action to human serum albumin: a computational study

Due to the pivotal role played by human serum albumin (HSA) in the transport and cytotoxicity of titanocene complexes, a docking study has been performed on a selected set of titanocene complexes to aid in the current understanding of the potential mode of action of these titanocenes upon binding HSA. Analysis of the docking results has revealed potential binding at the known drug binding sites in HSA and has provided some explanation for the specificity and subsequent cytotoxicity of these titanocenes. Additionally, a new alternative binding site for these titanocenes has been postulated

Impact of Compaction Mode on Strength Properties of Sustainable Asphalt Concrete

Various modes of compacting the asphalt concrete mixture can createmechanically different behaviour of the prepared specimens and can alterits sustainability. An attempt has been made in the present assessment toprepare asphalt concrete specimens by implementation of three modesof compaction, the gyratory, the roller, and the Marshall hammer. Thespecimens were prepared at the target bulk density of Marshall methodat optimum asphalt content. Extra specimens were prepared at 0.5 %asphalt below and above the optimum. Core specimens have been obtainedfrom the roller compacted slab samples. The specimens were tested forthe Marshall stiffness, tensile, and shear strength. It was observed that atoptimum asphalt content, the indirect tensile strength declines by (18.8and 70.5) % for gyratory and roller compacted specimens respectively ascompared with hammer compacted specimens. At optimum asphalt content,the shear strength declines by (70.5 and 82.2) % while Marshall stiffnessdeclines by (10.2 and 44.8) % for hammer and roller compacted specimensas compared with that of gyratory compacted specimen. Specimensprepared by gyratory compaction are less susceptible to the change inthe testing temperature as compared with other modes of compaction. Itis recommended to consider the mode of compaction to suit the requireddesign property of sustainable asphalt concrete mixture

Improving the effectivness of audit committee: a comparative analysis of audit committee codes in US, UK and Egypt

The audit committee performs a very important role in corporate governance. The main objective of this research is to enhance the audit committee effectiveness through, a comparison between codes and regulations of the Audit Committee in the U.K., U.S.A. and Egypt. Such comparison will highlight important issues related to Audit Committee activities and will result in modification to the existing Egyptian Code of Corporate Governance for Audit Committee. The importance of the research comes from the fact that the Audit Committee report became mandatory starting from 2009 for all listed companies in the EGX. The study conducted analyzed requirement in the British UK Code, The AICPA Audit Committee Toolkit: Public Companies and other research. Four hypotheses were developed and tested to assess the effect of Audit Committee characteristics including establishment and role, resources, skills and experience, Audit Committee relation with Board of Directors, financial reporting, internal control, whistle-blowing, internal audit function, external audit, annual audit cycle, and communication with shareholders on the effectiveness of the Audit Committee. For this reason, a survey was conducted to analyze the opinion of professionals like AC members, Accountants and Auditors, and the scholars in the education field for the improvement of Audit Committee in Egypt Code of Corporate Governance. Once data were collected, they were analyzed with the statistical software SPSS for implication for Egypt Code of Corporate Governance for Audit Committee. The data subjected to statistical analysis and procedures, including descriptive statistics, frequencies, percentages, mean, correlations and coefficient of variation. The overall analysis of the data gathered was strongly supportive of the 4 hypotheses. The researcher reached a conclusion, referring that, the regulatory initiative has a strong impact on the development of the Corporate Governance Code to be more comprehensive and detailed, on the road, to a proactive and more effective Audit Committee, which will empower the local investment environment and sustain higher rates of economic growth. The researcher recommends the deployment of the proposed provisions by the Egyptian Financial Supervisory Authority with continuous review of the Corporate Governance regulations every three years to catch up with the latest developments relative to the issue

Ltc1 is an ER-localized sterol transporter and a component of ER-mitochondria and ER-vacuole contacts.

Organelle contact sites perform fundamental functions in cells, including lipid and ion homeostasis, membrane dynamics, and signaling. Using a forward proteomics approach in yeast, we identified new ER-mitochondria and ER-vacuole contacts specified by an uncharacterized protein, Ylr072w. Ylr072w is a conserved protein with GRAM and VASt domains that selectively transports sterols and is thus termed Ltc1, for Lipid transfer at contact site 1. Ltc1 localized to ER-mitochondria and ER-vacuole contacts via the mitochondrial import receptors Tom70/71 and the vacuolar protein Vac8, respectively. At mitochondria, Ltc1 was required for cell viability in the absence of Mdm34, a subunit of the ER-mitochondria encounter structure. At vacuoles, Ltc1 was required for sterol-enriched membrane domain formation in response to stress. Increasing the proportion of Ltc1 at vacuoles was sufficient to induce sterol-enriched vacuolar domains without stress. Thus, our data support a model in which Ltc1 is a sterol-dependent regulator of organelle and cellular homeostasis via its dual localization to ER-mitochondria and ER-vacuole contact sites

Verifying Moisture Damage Impact in Asphalt Concrete with the Aid of Nondestructive Test NDT

One of the major concerns of pavement durability is its susceptibility to moisture damage. In this investigation, non-destructive test NDT has been implemented to detect the moisture damage issue. Asphalt concrete specimens were prepared using the traditional Marshall method for wearing, binder and asphalt stabilized base course. Specimens were traversed by ultrasound pulse velocity before and after practicing the moisture damage procedure. The variation of dynamic and elastic modulus before and after the moisture damage was considered and related to tensile strength ratio TSR. It was noted that the pulse velocity decline by (11, 11.2 and 16.4) % and the dynamic modulus declines by (28, 6.6 and 28.5) % for asphalt concrete wearing, binder and base courses respectively after moisture damage. The elastic modulus exhibits no significant variation after moisture damage for wearing course while it declines by (9 and 11.7) % for binder and base courses respectively after moisture damage. It was concluded that the elastic and dynamic moduli were unable to clearly distinguish the impact of moisture damage, whereas the Seismic modulus calculated from the Ultrasonic Pulse Velocity test was effective in distinguishing such impact. The linear equation obtained with good coefficient of determination can explain 74 % of the variation in the seismic modulus after moisture damage

Examining the effect of learners' gender on their learning achievement: Proposing a multimedia courseware

Although the use of multimedia web design in education has drawn the interest of instructors in the modern learning process, the role of gender in such a process has not yet explored properly. The purpose of this research is therefore to evaluate the effects of gender on learners’ achievements when studying from the proposed platform. Therefore, multimedia courseware was built at the very early stage. Then, the students were divided based on their gender into two groups (male and female). The learning performance of each group gets compared using t-test. Result showed that no significant difference occurs between the two groups. This means that the proposed design is equally fitting the learners of both genders. In addition, the result obtained has shown that gender has no effect on learners' output. In conclusion, this study provides a guideline for the design of multimedia courseware. It contributes to the theories of gender and learning to come up with a clear understanding of the type of design elements that can be used for positive learning experience

Influence of Iron-Filings on Marshall and Volumetric Properties of Asphalt Concrete

The growth and expansion of road infrastructure had resulted in the continuous use of materials, increased construction costs of flexible pavements and increased environmental impact during the service life of the road. Consequently, many researchers have sought to use methods to maintain these roadways sustain environmental impact and traffic loads. One of these approaches is the use of additives to improve asphalt's volumetric character. In this research, iron filings were used as partial replacement of fine aggregates, and the Marshall and volumetric properties were assessed before and after the implementation of iron filings. Specimens were prepared with iron filings addition of (2, 4, 6 and 8%) by weight of fine aggregates. The Marshall mix design procedure was used to calculate the optimum asphalt content and the volumetric properties, including bulk density, Total voids, voids in mineral aggregates V.M.A., and voids filled with asphalt V.F.A. The Marshall Flow and Stability were calculated. Test results were assessed before and after the inclusion of the iron filings. It was concluded that the addition of iron filings can enhance the Marshall and volumetric properties of asphalt. The stability increased by 15% when replacing fine aggregates by 2%, of iron filings by total weight. Also, the air voids and the VMA decreased by increasing the percentage of iron filings, while VFA was not significantly affected as compared to the conventional specimen. The ideal ratio of iron filings which fulfill the optimal requirements was 5%

Impact of Rejuvenators Type on Physical Properties of Aged Asphalt Cement

Recycling can be considered as one of the measures of sustainable methods. The physical traits of the asphalt mixture under the influence of accelerated aging (Long and Short–Term) for asphalt concrete were assessed. Asphalt cement (40-50), aggregate with 12.5 mm nominal extreme size and limestone dust as filler of the mineral was used for the preparation of asphalt concrete mixture. At the optimum content of the asphalt and asphalt of 0.5 percent below and above the optimum value, specimens were prepared by using Marshall Method. Two types of polymers as recycling agents were used (Polyethylene of Low Density and Crumb Rubber) with (0.5, 1 and 1.5) % by weight of the binder. The indirect tensile test was used for the mixtures at 25 ºC and double punch test at 60 ºC. It was determined that the use of (asphalt binder mixed with rubber) as the agent of recycling showed improved performance than the other kind of recycling agent. The indirect tensile strength at 40 ˚C of the recycled mixture was higher than that the control mixture. Punching shear strength was decreased by 84 %, temperature susceptibility was decreased by 69.6 % and the resistance to moisture damage increases by3.3 % at optimum asphalt content

A Study of the Basic Strength Components of Asphaltic Concrete

Generally speaking, pavements may be divided into two broad classifications, i.e. rigid and flexible. The term rigid pavement is applied only to wearing surfaces constructed of Portland Cement Concrete. The term flexible is used to denote the tendency of all layers to conform to the same shape under traffic. The basic concept in the design of flexible pavement is that a load applied to the surface is distributed over successively larger areas, as it is transmitted through each lower layer or course, until it has become so diminished in its intensity as to be less than the strength of the natural soil upon which the pavement rests. Therefore, the thickness of the flexible pavement structure is a function of the traffic loads, the load supporting characteristics of the native soil, and the structural properties of the several courses. It is the primary purpose of this study to evaluate with greater accuracy than has been done previously, the basic strength components of the bituminous surface course. The resistance to deformation under sustained or repeated loads. This resistance to deformation generally manifests itself in the form of cohesion, frictional resistance, and interlocking resistance. The process of mixture design must combine these three strength components so as to obtain a maximum resistance to deformation