Pedagogical Justifications That Zero Factorial Equals One

Zero factorial, defined to be one, is often counterintuitive to students but nonetheless an interesting concept to convey in a classroom environment. The challenge is to delineate the concept in a simple and effective way. This article reveals and makes contribution to much simpler justifications on the notion of zero factorial to be one when compared to previous studies in the area. We note that the connection of zero factorial to the definition of the gamma function provides a first-hand conceptual understanding of the concept of zero factorial. But for the purpose of teaching, it is not particularly helpful from the pedagogical point of view in early years of study, as it is quite challenging to explain the rationale behind the origin of the definite integral that defines the gamma function. In this regard two algebraic and one statistical justification are presented. The "squeeze theorem" plays a pivotal role in this article. To assess the effectiveness of the justifications pedagogically, an online survey was conducted at a Canadian university.Comment: 22 page

Studying and Modeling The Effects of Quartz Addition and Heat Treatment on Corrosion Properties of Ceramic Coating

In this work, a new glass-ceramic coating has been developed and applied, as a single coat without prior chemical treatment of the surface, by using the dipping technique on metal substrate. the coating are designed for application on varies grades of low alloy steel, the selected substrate was low carbon low alloyed steel with (0.2)%C. Various heat treatments at temperatures ( 500,550, and 600˚C ) at different times (60 & 120)min and with quartz addition in the range (0-15)% were used to obtain a glass-ceramics that have the optimum coating properties. These coating have been characterized by x-ray diffraction analyses and the results showed presence of a number of microcrystalline phases which are formed during the heat treatments. The results of corrosion resistance tests indicated that the acid resistance was greatly improved by addition of quartz into enamel frit but at same times decreased the alkali corrosion resistance, while the heat treatments improved both acid and alkali resistance for all cases, this is attributed to the formation of complex network from crystalline phases. The results also indicated that the heat treatment at 600˚C for 120min with 15% quartz addition brought the optimum values for acid resistance property which are improved by 86.66%, while the optimum values for alkali resistance property was brought with free quartz added samples which were treated at 600˚C for 120min. Mathematical modeling is implemented and regression equations are obtained by using ( SPSS ) software to predict the experimental data for acid and alkali corrosion rate. Comparing the predicted and measured values gives high prediction accuracy. The accuracy of prediction has been (82.58%, and 96.7%) for acid and alkali resistance properties respectively

Spray pyrolysis of Low Carbon Steel by Polymer Matrix Composite

In this research study the effect of spray pyrolysis that coating low carbon steel with epoxy reduced corrosion rate by (89.4%), while coated low carbon steel with epoxy composite reinforcement at 2%wt of (Al,TiO2, and Zn) was result the corrosion rate of coated specimens with epoxy composites reinforcement (Al, TiO2, and Zn) are lower than coated specimens with epoxy by (73.42%,91.75%,97.9%) respectively. The weight loss of low carbon steel coated with epoxy at90ºand 300 impingement angles are lower than those of uncoated specimens of low carbon steel by (51.06%,43.2%) respectively ,while the weight loss at90ºand 30º of coated specimens with epoxy composites reinforcement (Al,TiO2) lower than coated specimens with epoxy by (34.78%,17.39%)and (47.61%,23.80%) respectively. The weight loss of erosion characteristics at90ºand 300 of coated specimens with epoxy composites reinforced (Zn) are higher than coated specimens with epoxy by (34.78 %, 28.57%) respectively. The wettability determine by measuring the contact angle that are small than 70º signifies hydrophilic surfaces have high surface energies and good wettability. The adhesive strength of coated specimens with epoxy composite has low adhesive strength than that in coated specimens with. The used (AFM) to showed surface morphology and surface roughness of coated specimens with epoxy and epoxy composites .The Pore Size measurement of specimens surfaces coating by (SEM), signifies each type of coated specimens with epoxy composites decreased than with epoxy

Effect of Carbon Nanotube on Damping Characteristic of Epoxy Polysulfide Blend Composite

In a Nano-composite structure, it is anticipated that high damping can be achieved by taking advantage of the interfacial friction between the nanotubes and the polymer. The purpose of this paper is to investigate the structural damping characteristics of polymeric composites containing Carbon nanotubes (CNTs) with various amounts with polysulfide rubber (PSR) . The damping characteristics of the specimens with 0 wt% and 0.6 wt% Carbon nanotube contents were computed experimentally. Through comparing with neat resin specimens (epoxy, epoxy +PSR), the study showed that one can enhance damping by adding CNTs fillers into polymeric resins. Similarly experiment showed that the maximum value of damping ratio was obtained at 0.4 wt% CNTs

The SABRE Proof of Principle

SABRE is a dark matter direct detection experiment based on NaI(Tl) scintillating crystals. The primary goal of the experiment is to test the dark matter interpretation of the DAMA/LIBRA annual modulation signal. To reach its purpose, SABRE will operate an array of ultra-low background NaI(Tl) crystals within an active veto, based on liquid scintillator. Finally two twin detectors will be used, one in the northern hemisphere at Laboratori Nazionali del Gran Sasso, Italy (LNGS) and the other, first of its kind, in the southern hemisphere, in the Stawell Underground Physic Laboratory (SUPL). The collaboration has successfully developed a NaI(Tl) crystal with the impressive potassium content of about 4 ppb, according to the mass spectroscopy measurements. A value that, if confirmed, would be about 3 times lower than the DAMA/LIBRA crystals one. The first phase of the SABRE experiment, called SABRE Proof of Principle (PoP), aims to prove the achieved radiopurity by direct measurement of crystals at LNGS. This work reports the status of the PoP setup and the recent progresses on the development of low radioactivity NaI(Tl) crystals

SABRE and the Stawell Underground Physics Laboratory: Dark Matter Research at the Australian National University

The direct detection of dark matter is a key problem in astroparticle physics that generally requires the use of deep-underground laboratories for a low-background environment where the rare signals from dark matter interactions can be observed. This work reports on the Stawell Underground Physics Laboratory – currently under construction and the first such laboratory in the Southern Hemisphere – and the associated research program. A particular focus will be given to ANU’s contribution to SABRE, a NaI:Tl dark matter, direct detection experiment that aims to confirm or refute the long-standing DAMA result. Preliminary measurements of the NaI:Tl quenching factor and characterisation of the SABRE liquid scintillator veto are reported.I.M. and F.N acknowledge travel support from AINSE for their attendance at the ANU quenching factor measurements. This research was supported by the Australian Research Council, grant numbers DP170101675, LE160100080, LE170100162 and LE190100196

Global, regional, and national cancer incidence, mortality, years of life lost, years lived with disability, and disability-Adjusted life-years for 29 cancer groups, 1990 to 2017 : A systematic analysis for the global burden of disease study

Importance: Cancer and other noncommunicable diseases (NCDs) are now widely recognized as a threat to global development. The latest United Nations high-level meeting on NCDs reaffirmed this observation and also highlighted the slow progress in meeting the 2011 Political Declaration on the Prevention and Control of Noncommunicable Diseases and the third Sustainable Development Goal. Lack of situational analyses, priority setting, and budgeting have been identified as major obstacles in achieving these goals. All of these have in common that they require information on the local cancer epidemiology. The Global Burden of Disease (GBD) study is uniquely poised to provide these crucial data. Objective: To describe cancer burden for 29 cancer groups in 195 countries from 1990 through 2017 to provide data needed for cancer control planning. Evidence Review: We used the GBD study estimation methods to describe cancer incidence, mortality, years lived with disability, years of life lost, and disability-Adjusted life-years (DALYs). Results are presented at the national level as well as by Socio-demographic Index (SDI), a composite indicator of income, educational attainment, and total fertility rate. We also analyzed the influence of the epidemiological vs the demographic transition on cancer incidence. Findings: In 2017, there were 24.5 million incident cancer cases worldwide (16.8 million without nonmelanoma skin cancer [NMSC]) and 9.6 million cancer deaths. The majority of cancer DALYs came from years of life lost (97%), and only 3% came from years lived with disability. The odds of developing cancer were the lowest in the low SDI quintile (1 in 7) and the highest in the high SDI quintile (1 in 2) for both sexes. In 2017, the most common incident cancers in men were NMSC (4.3 million incident cases); tracheal, bronchus, and lung (TBL) cancer (1.5 million incident cases); and prostate cancer (1.3 million incident cases). The most common causes of cancer deaths and DALYs for men were TBL cancer (1.3 million deaths and 28.4 million DALYs), liver cancer (572000 deaths and 15.2 million DALYs), and stomach cancer (542000 deaths and 12.2 million DALYs). For women in 2017, the most common incident cancers were NMSC (3.3 million incident cases), breast cancer (1.9 million incident cases), and colorectal cancer (819000 incident cases). The leading causes of cancer deaths and DALYs for women were breast cancer (601000 deaths and 17.4 million DALYs), TBL cancer (596000 deaths and 12.6 million DALYs), and colorectal cancer (414000 deaths and 8.3 million DALYs). Conclusions and Relevance: The national epidemiological profiles of cancer burden in the GBD study show large heterogeneities, which are a reflection of different exposures to risk factors, economic settings, lifestyles, and access to care and screening. The GBD study can be used by policy makers and other stakeholders to develop and improve national and local cancer control in order to achieve the global targets and improve equity in cancer care. © 2019 American Medical Association. All rights reserved.Peer reviewe

Eroticism in the Works of Contemporary Egyptian and Levantine Female Novelists

Thesis (Master's)--University of Washington, 2018Literary and narrative discourses hold an inherent correspondence between themselves and the social, economic, national, and political issues that govern the atmosphere in which they emerge, including those concerning the war of the classes and of the sexes. Using the erotic as a parameter, this paper analyzes three novels by three contemporary women novelists from Egypt, Lebanon, and Syria: Nawāl el-Sa’dāwī, Ḥanān al-Shaykh, and Samar Yazbek, respectively. An analysis of the combination of language, culture, and space can lend itself to an examination of the relationships of power and social hierarchies that govern societies, in a fashion that follows the Foucauldian power/knowledge social theory. Adopting the Lacanian perspective of language as an inherently sexist utility, this paper examines the approaches found in these three novels to the objectification of the female body; the yearning to reclaim agency; and the success – and failure – in regaining and retaining autonomy

Characteristics and Properties of Epoxy/Polysulfide Blend Matrix Reinforced by Short Carbon and Glass Fibers

In this research, binary blends have been prepared from epoxy resin (EP) and different weight percentages of polysulfide rubber (PSR) (0%, 2.5%, 5%, 7.5 and 10%), and then compression, impact, and hardness tests were evaluated. The experimental results showed that the addition of polysulfide rubber in the epoxy resin decreased the compressive strength, Young's modulus, and hardness, while increased the impact resistance. It was found that the weight percentage 5% of polysulfide was the best percentage, which gives the best mechanical properties for the blend matrix. The advantage of this blend matrix is that, it mediates between the brittle properties of epoxy and the flexible properties of a blend matrix with the highest percentage of PSR. Short fibers (Carbon & Glass) with different volume percentage (2.5%, 5%, 7.5%, and 10%), were used to reinforce the best blend matrix obtained separately and randomly, and then the same mechanical tests conducted on these composites. The experimental results showed that the addition of fibers increased the compressive strength, Young's modulus, impact resistance and hardness. It was also observed that the composites materials reinforced with carbon fibers have significantly higher mechanical properties values than the composites materials reinforced with glass fibers