bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enhancing the Compressive Strength and Density of Cement Mortar by the Addition of Different Alignments of Glass Fibers and Styrene Butadiene Rubber
Authors: Hamza Mustafa M. , Fahad Besma M. 
Published: April 2019

Abstract
In the field of construction materials the glass reinforced mortar and Styrene Butadiene mortar are modern composite materials. This study experimentally investigated the effect of addition of randomly dispersed glass fibers and layered glass fibers on density and compressive strength of mortar with and without the presence of Styrene Butadiene Rubber (SBR). Mixtures of 1:2 cement/sand ratio and 0.5 water/cement ratio were prepared for making mortar. The glass fibers were added by two manners, layers and random with weight percentages of (0.54, 0.76, 1.1 and 1.42). The specimens were divided into two series: glass-fiber reinforced mortar without SBR and glass-fiber reinforced mortar with 7% SBR of mixture water. All specimens were tested after curing for 7 and 28 days, glass-fiber reinforced mortar exhibited better properties than control mortar in improvement of compressive strength and lowering the density after curing for 28 days due to the completion of cement hydration reaction.. For compressive strength the best results were achieved with 1.42 wt.% layers glass-fiber reinforced mortar with 7% SBR which gave 41.56 MPa. On the other hand, the addition of 1.42 wt.% random glass-fiber without SBR addition caused the beast reduction in density by 10.6% and produced lighter structure than control sample.
Keywords: Random glass fibers , Glass fibers layers, SBR, compressive strength, density.
Effect of optimal shot peening time on fatigue life for aluminum alloy 6061-T651
Authors: Al-Khazraji Ahmed N. 
Published: April 2019

The compressive residual stresses generated by shot peening, is increased in a direct proportional way with shot peening time (SPT). For each metal, there is an optimum shot peening time (O.S.T) which gives the optimum fatigue life. This paper experimentally studied to optimize shot peening time of aluminium alloy 6061-T651 as well as using of and analysis of variance (ANOVA).
Two types of fatigue test specimens’ configuration were used, one without notch (smooth) and the other with a notch radius (1,25mm), each type was shot peened at different time. The (O.S.T) was experimentally estimated to be 8 minutes reaching the surface stresses at maximum peak of -184.94 MPa.
A response surface methodology (RSM) is presented to optimize the surface properties of fatigue life due to effect of two parameters (shot peening time and fatigue stresses). A statistical software was used to perform analysis of variance (ANOVA) to predict the optimum shot peening time. The results were 8.007 minutes without notch and 7.53 minutes with notch. Two 2nd degree polynomials were obtained for the two studied cases with confidence level of 95%. Experimentally26.67% enhancement in fatigue life was obtained, but after using (RSM), the results gave 61% improvement, compared with ref. [2].
Experimental Study to the Effect of Natural Particles Added to Unsaturated Polyester Resin of a Polymer Matrix Composite
Authors: Abdullah Orhan S. 
Published: April 2019

Experimental investigations had been done in this study to demonstrate the effect of natural particles used as a reinforcement material to unsaturated polyester resin. The tensile test and water absorption were investigated according to (ASTM D638) and (ASTM D570), respectively. The influence of sunflower husk and pomegranate husk particles, used as a reinforcement material, on the tensile strength, Young's modulus and water absorption with different weight fraction (3%, 7% and 10%) and particle grain size (50µm, 100 µm and 150 µm), has been investigated. The water absorption of polymer composites was studied by measuring the specimen weight before and after immersion in water for one hundred days. In the experiments of tensile test, all specimens loading was performed with (50KN) operating at a crosshead speed of 10 mm/min. It is observed that the addition of sunflower husk up to 10% and pomegranate husk particles up to 7% as reinforcement materials to polyester resin, leads to increase the tensile strength and Young's modulus of the composite material prepared and the use of sunflower husk as a reinforcement material increased the tensile strength, Young's modulus and water absorption were better than pomegranate husk at the same percentage of addition. The decrease in reinforcement material grain size led to increase the tensile strength, Young's modulus and water absorption. Therefore, all the best result seen in composites containing reinforcement material with (50µm). Finally, the best result obtained in tensile strength, Young's modulus and water absorption were with the addition of 10% sunflower husk as a reinforcement material to polyester resin.
Evaluations of Potable Water Tanks Epoxy Coatings Performance Using Electrochemical Impedance Spectroscopic Method
Authors: Jasim Haider Hadi 
Published: April 2019

Abstract
The aim of this paper is to investigate and discuss the mechanisms of corrosion of epoxy coatings used for potable water tanks. Two distinct types of Jotun epoxy coatings: Tankguard 412 contained polyamine cured epoxy and Penguard HB contained polyamide cured epoxy, were tested and studied using the electrochemical impedance spectroscopic (EIS) method. The porosity of epoxy coatings was determined using EIS method. The obtained results showed that the two epoxy coatings have excellent behavior when applied and tested in potable water of Basrah city. Polyamine is more resistance to water corrosion compared to polyamide curing epoxy and has high impedance values. Microscopic inspection after test showed that the polyamine cured epoxy has blistering while the surface of polyamide cured epoxy showed pitting and blisters.
Keywords: Corrosion mechanism , epoxy coats, porosity, potable water, , EIS method.
Experimental Study the Effect of Tool Design on the Mechanical Properties of Bobbin Friction Stir Welded 6061-T6 Aluminum Alloy
Authors: Amin Samir Ali , Hanna Mohannad Yousif , Mohamed Alhamza Farooq 
Published: April 2019

اللحام بالخلط الاحتكاكي بأداة تشبه البكرة (bobbin) يكون مختلف عن اللحام المتعارف علية للطريقة نفسها, حيث يتم لحام قطعة العمل من الوجهين الاعلى و الاسفل في للشوط نفسها . يتضمن هذا الأسلوب لحام اللوحين من دون الانصهار. في هذا العمل، تم التحقق من تأثير تصميم الأداة على الخواص الميكانيكية لوصلات اللحام لسبيكة الالمنيوم نوع (6061-T6) و بسمك (6,25 ملم) والملحومة بطريقة اللحام الخلطي الاحتكاكي نوع (bobbin)،و كذلك تحديد أفضل تصميم لأداة اللحام نوع (bobbin). خمسة أشكال مختلفة لوتد أداة اللحام (أسطواني مستقيم مسنن, أسطواني مستقيم ذو 3 أوجه، أسطواني مستقيم ذو 4 أوجه، أسطواني مستقيم مسنن ذو 3 أوجه و أسطواني مستقيم مسنن ذو 4 أوجه) وبأبعاد مختلفة للأداة ( الدبوس و الأكتاف ) استخدمت لأجراء عملية اللحام. أتجاه عملية اللحام كان عموديا على أتجاه الدرفلة لألواح الألمنيوم. اختبارات الشد والانحناء تم اجراؤها لأختيار التصميم الأفضل لأداة اللحام نوع (bobbin) والتي تعطي افضل الخواص الميكانيكية لمنطقة اللحام. الأداة ذات الاسطواني المستقيم ذو 4 أوجه، بقطر للوتد (8 mm) والاكتاف (24 mm) أعطت افضل مقاومة شد (193 ميكا باسكال) وأستطالة (6.1%) مع أقصى قوة انحناء (5.7 كيلو نيوتن) وأفضل كفاءة لحام (65.4%) نسبة الى مقاومة الشد.
Enhancement of Hybrid Solar Air Conditioning System using a New Control Strategy
Authors: Mohammed Ahmed Abed , Abduljabbar Raed Ayad 
Published: April 2019

Enhancement of the performance for hybrid solar air conditioning system was presented in this paper. The refrigerant temperature leaving the condenser was controlled using three-way valve, this valve was installed after the compressor to regulate refrigerant flow rate towards the solar system. A control system using data logger, sensors and computer was proposed to set the opening valve ratio. The function of control program using LabVIEW software is to obtain a minimum refrigerant temperature from the condenser outlet to enhance the overall COP of the unit by increasing the degree of subcooled refrigerant. A variable load electrical heater with coiled pipe was used instead of the solar collector and the storage tank to simulate the solar radiation. Experimental data was measured to study the performance of the system. The proposed system was compared with the conventional one. Results show that the COP of the proposed system was higher than the COP of the conventional system by 10 %. In addition, the controlled system saved an electricity of 11.2 %. The optimum opening valve ratio fluctuated between 0.3 and 0.4 when the heater power was 500 W.
Analisis Keterlaksanaan Model Kooperatif Tipe NHT dan Pengaruhnya terhadap Kemampuan Berpikir Kritis
Authors: Asrial Asrial , Simaremare Erika , Harizon Harizon 
Published: April 2019

Penelitian ini bertujuan untuk menganalisis keterlaksanaan model pembelajaran kooperatif tipe Number Heads Together dan pengaruhnya terhadap kemampuan berpikir kritis pada materi larutan penyangga siswa kelas XI MIA SMAN 1 Muaro Jambi. Penelitian ini merupakan jenis penelitian deskriptif korelasional dengan teknik pengambilan sampel cluster random sampling. Instrumen yang digunakan yaitu lembar observasi aktivitas guru dan siswa serta tes kemampuan berpikir kritis siswa. Untuk melihat pengaruh keterlaksanaan model pembelajaran kooperatif tipe NHT dengan kemampuan berpikir kritis siswa dilakukan uji signifikansi dengan uji t. Penerapan model pembelajaran kooperatif tipe Number Heads Together oleh siswa sebesar 70,83% dikategorikan baik, dan persentase kemampuan berpikir kritis siswa sebesar 70,47% dikategorikan baik. Hubungan keterlaksanaan model pembelajaran kooperatif tipe Number Heads Together dengan kemampuan berpikir kritis diperoleh rxy = 0,86294 dengan tingkat hubungan sangat kuat. Uji signifikansi dilakukan dengan uji t dengan diperoleh thitung > ttabel (9,660 > 2,036) dengan dk = 32 dan α = 0.05, sehingga H0 ditolak dan Ha diterima. Berdasarkan hasil penelitian, keterlaksanaan model pembelajaran kooperatif tipe Number Heads Together berjalan dengan baik dan terdapat pengaruh keterlaksanaan model pembelajaran kooperatif tipe Number Heads Together terhadap kemampuan berpikir kritis siswa pada materi larutan penyangga di kelas XI MIA 2 SMAN 1 Muaro Jambi.

Kata kunci: Model Number Heads Together, Berpikir Kritis dan Larutan Penyangga
ANALISIS KETERLAKSANAAN MODEL PEMBELAJARAN INKUIRI TERBIMBING UNTUK MATERI SIFAT KOLIGATIF LARUTAN DAN PENGARUHNYA TERHADAP KEMAMPUAN BERPIKIR KREATIF SISWA KELAS XII IPA SMA ISLAM AL-FALAH KOTA JAMBI
Authors: Naswir Muhammad , Haryanto Haryanto , Wati Fera 
Published: April 2019

Lack of active students in following the learning resulted in the ability of students to think in the learning process is low, let alone in the ability to think creatively. Students tend to learn by memorization, without the students finding themselves learning it. One alternative to making students actively discover their own learning is to use guided learning model of inkury. This study aims to determine the implementation of guided inquiry learning model on the ability of creative thinking, and student learning outcomes on the material nature of colligative solutions in class XII science high school Islam Al-Falah City Jambi. This research is a mixed research (mix method) by prioritizing qualitative data and then new quantitative data as primary data. The sampling technique was done by purposive sampling that was class XII IPA.1 as the sample class. The instrument used in this research is an observation sheet to see the model execution by teacher, student, and creative thinking, and essay test is used to see student learning result. Data analysis technique used in this research is 2 that is qualitative data analysis technique using Miles and Huberman obtained from observer comment on observation sheet, and quantitative data analysis technique using correlation of memoment product obtained from model implementation data by teacher, student, creative thinking , as well as data on student learning outcomes. The implementation of inquiry learning model guided by teachers and students has been done well seen the activities of teachers and students have increased each meeting. The correlation of the implementation of guided inquiry model with creative thinking ability is categorized with the value of rxy 0.43, while the ability of creative thinking with student learning outcomes is very low category with rxy value 0.17. Based on the results of this study it can be concluded that the implementation of guided inquiry learning model positively influences on the material of the colligative nature of the solution in class XII IPA.1 to the creative thinking ability of the students.
Can the Use of nonlinear Color Metrics systematically improve Segmentation?
Authors: Ramos de Carvalho Luís Eduardo , Mantelli Neto Sylvio Luiz , Comunello Eros , Sobieranski Antonio Carlos , Von Wangenheim Aldo 
Published: April 2019

Image segmentation is a procedure where an image is split into its constituent parts, according to some criterion. In the literature, there are different well-known approaches for segmentation, such as clustering, thresholding, graph theory and region growing. Such approaches, additionally, can be combined with color distance metrics, playing an important role for color similarity computation. Aiming to investigate general approaches able to enhance the performance of segmentation methods, this work presents an empirical study of the effect of a nonlinear color metric on segmentation procedures. For this purpose, three algorithms were chosen: Mumford-Shah, Color Structure Code and Felzenszwalb and Huttenlocher Segmentation. The color similarity metric employed by these algorithms (L2-norm) was replaced by the Polynomial Mahalanobis Distance. This metric is an extension of the statistical Mahalanobis Distance used to measure the distance between coordinates and distribution centers. An evaluation based upon automated comparison of segmentation results against ground truths from the Berkeley Dataset was performed. All three segmentation approaches were compared to their traditional implementations, against each other and also to a large set of other segmentation methods. The statistical analysis performed has indicated a systematic improvement of segmentation results for all three segmentation approaches when the nonlinear metric was employed.
FRASEOLOGIAS ESPECIALIZADAS EM LIVROS DIDÁTICOS DE ESPANHOL: UMA ANÁLISE BASEADA NA TEORIA COMUNICATIVA DA TERMINOLOGIA
Authors: Teer Jacqueline Vaccaro 
Published: April 2019

Este trabalho analisa a fraseologia especializada apresentada na coleção Español Esencial, dirigida ao ensino de espanhol como língua estrangeira para alunos brasileiros. Para essa análise, nos baseamos nos pressupostos da Teoria Comunicativa da Terminologia (TCT), pois é uma teoria que não parte do termo como objetivo de análise, e sim do texto. Consegue, sendo assim, dar conta do caráter essencialmente discursivo das Unidades Fraseológicas Especializadas (UFE). Outro ponto importante dessa teoria é que não só considera os aspectos linguísticos dos objetos de análise, como também os comunicativos e cognitivos. Como resultados, observamos que há UFE na coleção estudada e que elas, juntamente com os termos, contribuem para a representação e transmissão do conhecimento especializado.
Saddle-node bifurcation in the dynamic analysis of a national energy market
Authors: Redondo Johan Manuel , Olivar Tost Gerard , Ibarra-Vega Danny , Peña-Rincon Carlos 
Published: April 2019

This article presents preliminary results of the mathematical analysis of a national energy market. The modeling of the studied system was made from causal relationships between the supply and demand of a national energy market, obtaining a system of ordinary differential equations of the first order of the electric power capacity in construction, the electric power capacity installed and the price of electricity in the market (Redondo et.al, 2018). In the dynamic analysis of the model, a saddle-node bifurcation was identified for the case in which the elasticity of the price with respect to the reserve margin is considered null, which allowed establishing two prospective scenarios of the system: absolute disappearance of the supply of electricity or tendency of growth of the supply to the attention of the demand of the market
Fundamental Analysis Redux
Authors: Sloan Richard G. 
Published: April 2019

ABSTRACT
In their classic text Security Analysis, Graham and Dodd (1934) warn investors against sole reliance on a few quantitative factors in investment decisions. Instead, they recommend that investment decisions be based on a comprehensive fundamental analysis of the underlying securities. While their views held sway for many decades, recent years have witnessed a sharp reversal. Scholars of finance often overlook fundamental analysis, and their influence has led to a surge of investment products relying solely on a few quantitative factors. These products often have names that appeal to fundamental analysis, such as “value” and “quality.” I argue that Graham and Dodd's (1934) recommendations continue to have merit. I show how popular quantitative approaches to investing overlook important information and select stocks with distorted accounting numbers rather than temporary mispricing. I conclude that informative financial reporting and comprehensive fundamental analysis are essential for the efficient functioning of capital markets.
Data Availability: Data are publicly available from sources indicated in the text.
Optimalisasi Peran Kepala Sekolah dalam Implementasi Kurikulum 2013
Authors: Wahyudin Wahyudin 
Published: April 2019

Dalam memberdayakan masyarakat dan lingkungan di sekolah, kepala sekolah merupakan kunci keberhasilan yang harus menaruh perhatian tentang apa yang terjadi pada peserta didik di sekolah dan apa yang dipikirkan orang tua dan masyarakat tentang sekolah. Kepala Sekolah dituntut untuk senantiasa berusaha membina dan mengembangkan hubungan kerjasama yang baik antara sekolah dan masyarakat guna mewujudkan sekolah yang efektif dan efesien. Peran kepala sekolah dengan hadirnya kurikulum 2013 perlu dioptimalkan, karena kunci sukses pertama yang menentukan keberhasilan implementasi kurikulum 2013 adalah kepala sekolah, terutama dalam mengoordinasikan, menggerakan, dan menyelaraskan semua sumber daya pendidikan yang tersedia. Kepala sekolah merupakan faktor penentu yang dapat menggerakan semua sumber daya sekolah untuk mewujudkan visi, misi, tujuan dan sasaran sekolah melalui program-program yang dilaksanakan secara terencana dan bertahap. Keberhasilan kurikulum 2013 menuntut kepala sekolah yang demokratis, mandiri dan profesional, sehingga mampu menumbuhkan iklim demokratis di sekolah, yang akan mendorong terciptanya iklim yang kondusif untuk kualitas pendidikan dan pembelajaran yang optimal untuk mengembangkan seluruh potensi peserta didik. Peran aktif kepala sekolah sangat menentukan kemajuan sekolah dalam berbagai bidang, dengan tampil sebagai pigur yang harus mampu memimpin tenaga kependidikan di sekolah, agar bisa bekerja sama dengan orang tua dan masyarakat pada umumnya dalam implementasi kurikulum 2013. Tulisan ini berupaya untuk memberikan gagasan kepada kepala sekolah untuk lebih optimal didalam menjalankan peran nya di lembaga pendidikan yang dikelola nya terutama dalam implementasi kurikulum 2013 yang telah di tetapkan oleh pemerintah sebagai kurikulum yang berbasis kompetensi dan berbasis karakter.
Interiors of Memories: A study of personal memories based on the works of Luigi Serafini and Georges Perec
Authors: Choueiri Joanne , Türetken Füsun 
Published: April 2019

Interiors of Memories: A study of personal memories based on the works of Luigi Serafini and Georges Perec is a collection of domestic spaces that uses memory as a foundation for the creation of new forms of interiors. These interiors, fantastic in nature, attempt to redefine the existing programmatic functions of the home.
Built on the study of Italian illustrator Luigi Serafini’s Codex Seraphinianus (1981) and French writer Georges Perec’s Species of Spaces and Other Pieces (1997), the authors’ memories are used to expand the understanding of space beyond its physical constraints. The in-depth exploration of both oeuvres enabled the realisation of these spaces.
The constructed spaces question the use of memory as a source material for the interpretation of various rooms of the home. The research reconstituted the entrance, the stairs, the kitchen, guest toilet, and the bedroom and re-evaluated a domestic typology and its programmatic functions. The interior spaces created merged with intangible memories enabling a shift from preset rules and functions, allowing for a different reading of the domestic interior.
The urban creative factory-creative ecosystems and (im)material design practices
Authors: Koutsari Maria , Antonopoulou Elena , Chondros Christos 
Published: April 2019

Post-Fordism, with its evolution towards immaterial production in the areas of information, knowledge and affective, creative commerce, foregrounds design as a central, enabling activity. If this enablement finds particular application in cities of the Global North, it testifies to a shift in the geopolitical distribution of productive agency and application of international labour, one that sees industrial activities ‘reassigned’ to the Global South, leaving cities of the variably de-industrialised countries to develop cultural, symbolic, and creative economies.
This paper examines the nature of urban place and the work regimes practised there consequent to these economies. It argues firstly for ‘cityness’ in these context to be understood as a creative urban factory – a place where older managerial and organisational techniques applied to factory environments in the service of high productivity are recalibrated and diffused across the entirety of urban territories. Secondly, the paper links the productivity of the creative urban factory with a biopolitical makeover of cities themselves, seeing in an optimisation of productive capacity a situation where the entirety of living labour is taken up and commoditised via the production of ever-customised lifestyles and identities. A raft of new identifying subject and worker categories emerge that exceed or elude the older class identifications, and with it, a certain potential to collectively counter the exploitation inherent post-Fordist work. While exploring the possibility of new identifying collectives – what Hardt and Negri have referred to as the multitude – the paper makes an argument for design itself to be a key medium for rethinking and re-enacting collective agency.
As the harbinger of new forms of user participation and co-operative processes that are, by way of emerging technological tools, open, evolving, ad hoc, reflexive and customisable, design practice increasingly must contend and adapt to forms of de-professionalisation. Rather than seeing in this adaption a demise in profession position, the new possibilities appearing in design point to a low-tech, yet digitally-driven enabled, re-politicisation of design and creativity, one better able to contend with the strictures of the urban creative factory.
On the origin of the architect: Architects and xenía in the ancient Greek theatre
Authors: Weir Simon 
Published: April 2019

Ubiquitous in ancient Greek culture, the ethical principle of xenía may broadly translate as hospitality to strangers, doing so through taking interpersonal, political, and architectural form. Since xenía includes the accommodation of foreign guests, some evidence of xenía in architecture is logically found in houses and hostels, but surprisingly more evidence surrounds Athens’ Theatre of Dionysus, on stage in Aristophanes’ Peace and Euripides’ Cyclops, and off stage through the architects elected to look after the sanctuary of the theatre.
This paper reveals the principle of xenía permeating the professional work of the architect to such a degree that Vitruvius and Demosthenes would reproach even slight digressions from the principle, and Vitruvius would call the education of xenía the most valuable thing to outlast a shipwreck.