Moisture-induced damage is a serious problem that severely impairs asphaltic pavement and affects road serviceability. This study examined numerous variables in asphalt concrete mixtures to assess their impact on moisture damage resistance. Mix design parameters such as the asphalt content (AC) and aggregate passing sieve No. 4 (PNo. 4) were considered as variables during this study. Additionally, hydrated lime (HL) was utilized as a partial substitute for limestone dust (LS) filler at 1.5% by weight of the aggregate in asphalt concrete mixtures for the surface layer. This study also investigated the potential enhancement of traditional asphalt binders and mixtures by adding nano-additives, specifically nano-silica oxide (NS) and nano-titanium dioxide (NT), at rates ranging from 0% to 6% by weight of the asphalt binder. To quantify the moisture damage resistance of the asphalt concrete mixes, two types of laboratory tests were employed: the tensile strength ratio (TSR) and the index of retained strength (IRS). The former characterizes moisture damage using tensile strength, whereas the latter uses compression strength. The physical properties of the asphalt binder, such as its penetration, softening point, and ductility, were also evaluated to identify the effects of the nanomaterials. The results indicated that variations in the mix design variables significantly affected the moisture damage resistance of the asphalt concrete mixtures. The maximum improvement values were obtained at the optimum asphalt content (OAC) and PNo. 4 (mid-range + 6%) with TSR values of 80.45 and 82.46 and IRS values of 74.39 and 77.14, respectively. Modifying asphalt concrete mixtures with 1.5% HL resulted in improved moisture resistance compared with mixtures without HL (0% HL) at each PNo. 4 level, reaching superior performance at PNo. 4 (mid-range + 6%) by 4.58% and 3.96% in the TSR and IRS tests, respectively. Additionally, both NS and NT enhanced the physical properties of the asphalt binder, leading to substantial enhancements in asphalt concrete mixture performance against moisture damage. A 6% dosage of NS and NT showed the best performance, with NS performing slightly better than NT. TSR was increased by 14.72 and 11.55 and IRS by 15.60 and 12.75, respectively, with 6% NS and NT compared with mixtures without nanomaterials (0% NM).
This study aimed to assess orthodontic postgraduate students’ use of social media during the COVID-19 lockdown. Ninety-four postgraduate students (67 master’s students and 27 doctoral students) were enrolled in the study and asked to fill in an online questionnaire by answering questions regarding their use of social media during the COVID-19 lockdown. The frequency distributions and percentages were calculated using SPSS software. The results showed that 99% of the students used social media. The most frequently used type of social media was Facebook, 94%, followed by YouTube, 78%, and Instagram, 65%, while Twitter and Linkedin were used less, and no one used Blogger. About 63% of the students used elements of social media to l
... Show MoreIn order to promote sustainable steel-concrete composite structures, special shear connectors that can facilitate deconstruction are needed. A lockbolt demountable shear connector (LB-DSC), including a grout-filled steel tube embedded in the concrete slab and fastened to a geometrically compatible partial-thread bolt, which is bolted on the steel section's top flange of a composite beam, was proposed. The main drawback of previous similar demountable bolts is the sudden slip of the bolt inside its hole. This bolt has a locked conical seat lug that is secured inside a predrilled compatible counter-sunk hole in the steel section's flange to provide a non-slip bolt-flange connection. Deconstruction is achieved by demounting the tube from the t
... Show MoreBackground: This study was performed to compare the marginal fit changes and facture resistance of metal ceramic crowns constructed from Ceramill Sintron metal coping veneered with three different porcelain veneering materials (Vita Master Koromikos VMK, Willi Geller Creation CC and GC initial MC), also to evaluate the influence of thermocycling on load at fracture. Materials and Methods: Master brass die was scanned ,then metal coping was designed and milled from Ceramill Sintron blank to get 60 metal copings, then divided randomly into three groups(20 sample), then veneered with porcelain: VITA, Creation or GC. The marginal gaps were measured before and after porcelain veneering then marginal fit changes was calculated. Fracture resist
... Show MoreBackground: This study was conducted to assess the effect of sonic activation and bulk placement of resin composite in comparison to horizontal incremental placement on the fracture resistance of weakened premolar teeth. Materials and method: Sixty sound human single-rooted maxillary premolars extracted for orthodontic purposes were used in this study. Teeth were divided into six groups of ten teeth each: Group 1 (sound unprepared teeth as a control group), Group 2 (teeth prepared with MOD cavity and left unrestored), Group 3 (restored with SonicFill™ composite), Group 4 (restored with Quixfil™ composite), Group 5 (restored with Tertic EvoCeram® Bulk Fill composite) and Group 6 (restored with Universal Tetric EvoCeram® co
... Show MoreBackground: Complete seal of the root canal system following its chemo-mechanical debridement plays a pivotal role for achieving successful endodontic treatment. This can be established by reducing the gaps between the core filling material and root canal wall. Aim: To assess and compare the dislocation resistance of root canals obturated with GuttaFusion® and TotalFill BC sealer versus single cone obturation technique and TotalFill BC sealer after instrumentation of the canals with WaveOne, ProTaper Next and ProTaper Universal system. Material and Method: Sixty extracted human permanent mandibular premolars were conducted in the current study. The teeth were decorated and left the root with 15mm length; the roots were divided randoml
... Show MoreThe research aims to determine the role of knowledge management to measure performance on a sample of faculties of Administration and Economics the University of Kufa, and to achieve this goal through a researcher from the theoretical literature and research and studies related to the construction of the scheme shows the hypothetical relationship between the variables, which was adopted by the independent variable knowledge management, distributed four variables are: (knowledge generation, knowledge storage, knowledge dissemination, the application of knowledge), as well as four variables representing the variables adopted for the performance of the university are:
(to reduce costs and increase profits, improve quality, scie
Abstract As the United Nations approaches its 70th anniversary, the world is going through the most severe accumulation of serious international security failures in recent memory, challenging the UN Security Council’s ability to address them effectively. Over the past four years, crises in Libya, Syria and Ukraine have precipitated a worrisome erosion of great power relations that has complicated Security Council decision making on a number of trouble spots. Its inability to devise consensus responses to the escalating civil war in Syria has been particularly troubling, resulting in the regional spill over into Iraq and the emergence of Islamic State as a new threat to peace in the region and beyond. Meanwhile, the UN’s often under
... Show MoreThis study showed the basic features of corporate tax in Iraq by showing what was in the Income Tax Law in force .The study aims of this to indicate the role of tax corprates in tax revenue and then the possibility of strengthening the revenue of this tax as an important source of local funding sources in the form that is with him reduce dependence on oil revenues to finance the general budget in Iraq, the risks and the study found a number of conclusions from the most important: that the corporate tax comes in the introduction to the components of the income tax structure in terms of relative importance and formed a revenue source of prime The gross proceeds of the income tax in Iraq, where it contributed to more than a quarter of that
... Show MoreAbstract:
Recently, there is a widespread attention about the service at the level of each of the research and academic studies, and at the organizational level as well. The subject of orientation towards the service aspect is starting to be of this attention being of the modern subjects, relatively, which appeared at the end of the last century, as well as the link of this subject with the relationship between the organization and its customers, and how to provide high quality services to get their satisfaction. Thus, the specialists from researchers were interested in this field to develop an appropriate scale to measure the organizational orientation toward service, and it was the most prominen
... Show MoreThe current research aims to focus on strategic vigilance dimensions and contained (environmental vigilance, technological vigilance, competitive vigilance, vigilance marketing) to improve nursing services, which include a) the quality, timeliness, problem-solving and decision-making, relationships with others, leadership skills) and measure the degree link and influence between strategic vigilance in the hospital respondent and improve nursing service that the problem of the research lies in the weakness of strategic plans and health organizations in general and the hospital surveyed (martyr Ghazi al-Hariri), in particular, the lack of awareness of the hospital researched strategy vigilant management to improve nursing services,
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