scholarly journals Microstructural, Mechanical and Radiological Characterization of Mortars Made with Granite Sand

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5656
Author(s):  
Francisca Puertas ◽  
José Antonio Suárez-Navarro ◽  
Alfredo Gil-Maroto ◽  
Ana María Moreno de los Reyes ◽  
Catalina Gascó ◽  
...  

The study reported the effect of granite sand on strength and microstructural developments in mortars prepare from OPC with a high coal fly ash (FA) content or from hybrid alkaline cements. The radiological behaviour of the resulting mortars was compared to materials prepared with siliceous sand (with particles sizes of <2 mm) and the relationship between such radiological findings and mortar microstructure and strength was explored. A new method for determining natural radionuclides and their activity concentration Index (ACI) on cement mortars (specifically to solid 5-cm cubic specimens) was applied and validated. The microstructural changes associated in mortars have no effect on mortar radiological content measurements. The mortars with granite sand exhibited very high ACI > 0.96, which would ultimately limit their use. A conclusion of interest is that where information is at hand on the starting materials (OPC, FA, sand, admixtures), their proportions in the mortar and the mixing liquid content (water or alkaline activators) their radiological content is accurately predicted. The inference is that a mortar’s radiological content and ACI can be known prior to mixing, providing a criterion for determining its viability. That in turn lowers environmental risks and the health hazards for people in contact with such materials.

Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.


Author(s):  
A.K. Rai ◽  
A.K. Petford-Long ◽  
A. Ezis ◽  
D.W. Langer

Considerable amount of work has been done in studying the relationship between the contact resistance and the microstructure of the Au-Ge-Ni based ohmic contacts to n-GaAs. It has been found that the lower contact resistivity is due to the presence of Ge rich and Au free regions (good contact area) in contact with GaAs. Thus in order to obtain an ohmic contact with lower contact resistance one should obtain a uniformly alloyed region of good contact areas almost everywhere. This can possibly be accomplished by utilizing various alloying schemes. In this work microstructural characterization, employing TEM techniques, of the sequentially deposited Au-Ge-Ni based ohmic contact to the MODFET device is presented.The substrate used in the present work consists of 1 μm thick buffer layer of GaAs grown on a semi-insulating GaAs substrate followed by a 25 Å spacer layer of undoped AlGaAs.


2019 ◽  
Vol 3 (2) ◽  
pp. 117-137
Author(s):  
Mustaqim Makki

Zakat merupakan salah satu sendi pokok ajaran Islam. Urgensi zakat yang merupakan anjuran agama Islam untuk menunaikan zakat dan memberikannya kepada yang berhak dengan ketentuan mencapai nishabnya, (kadar minimum harta tertentu) mempunyai nilai sangat signifikan dalam kehidupan manusia. Seorang insan yang sarat akan segala permasalahan pada fitrahnya menuntut untuk selalu berinteraksi kepada sesama, baik berupa materi maupun non materi. Zakat merupakan maliyah ijtima’iyyah yang mengandung nilai-nilai filantropi yang sangat tinggi, karena ketika mengaplikasikan kewajiban zakat kita telah membantu sesama serta mengurangi kesenjangan yang disebabkan beberapa sifat manusia diantaranya adalah sifat kikir, dengki dan iri hati. Menguatnya kembali harapan banyak kalangan terhadap implementasi filantropi Islam, baik dalam bentuk zakat, infak, sedekah, dan wakaf, memiliki keterkaitan erat dengan kondisi bangsa yang belum sepenuhnya bangkit dari keterpurukan sebagai dampak dari krisis ekonomi yang berkepanjangan. Kondisi ini berakibat kesenjangan penguasaan perekonomian antar warga negara menjadi kian lebar. Pada saat itulah, ziswaf (zakat, infak, sedekah, dan wakaf) kembali dilirik dan diharapkan menjadi alternatif solusi terhadap problem kemiskinan umat. Manusia sebagai khalifah fil ardh dalam Al Qurán menekankan muatan fungsional yang harus diemban oleh manusia dalam melaksanakan tugas-tugas kesejarahan dalam kehidupannya di muka bumi. Kaitan dengan konsep tersebut, ada dua fungsi manusia. Pertama: Manusia sebagai hamba (ábid), dituntut untuk sukses menjalin hubungan secara vertikal dalam hal ini hubungannya dengan ketuhanan (Teologis). Kedua adalah manusia sebagai khalifah, dituntut untuk sukses menjalin hubungan secara horizontal dalam hal ini hubungan terhadap manusia.Kata kunci: tafsir ayat zakat, filantropi, ekonomi keummatanAbstract:Zakat is one of the main points of Islamic teachings. The urgency of zakat which is suggested by Islam to fulfill and give it to those who are referred to with the provisions to reach their nishab, (minimum level of certain assets) has a very significant value in human life. A person who is full of all problems in his/her natural demands will always get interaction with other people, either material or non-material. Zakat is maliyah ijtima’iyyah which contains very high philanthropic values, because when applying the obligation of zakat we have helped others and reduced the gaps caused by some human traits including miser, jealousy and envy. The reinforcement of the expectations (estimation) from any levels on the implementation of Islamic philanthropy, which in the form of zakat, donation, alms and endowments, has a close relationship with the condition of the country that has not fully risen from bad economic adversity due to economic crisis. This condition causes a widening of the economic mastery among the citizens. At that moment, ziswaf (zakat, infaq, alms, and waqf) was again given a serious attentition and expected to be an alternative solution to the problem of poverty among citizens. Humans as khalifah fil ardh in the Qur'an emphasize the functional content that must be carried by humans in carrying out historical tasks in their lives on earth. In accordance with this concept, there are two human functions. First: Humans as servants (ábid), are required to succeed in establishing a vertical relationship in this case the relationship with God (Theological). Second, humans as caliphs, are required to succeed in establishing horizontal relationships in this case the relationship to humans.


Author(s):  
Evi Rosita ◽  
Siti Nurnaningrum

There are about 2.8 million incident of perineal rupture in maternal physiological labor. In 2050,it is estimated that the incidence of perineal rupture can be 6.3 million if it is not accompanied by a good midwifery care. In 2016, in Trawas, there was (89%) perineal rupture in primiparas and (57%) perineal rupture in multiparas. Perineal rupture incidences due to parity were still very high. This study aims to analyze the relationship between parity and the incidence of perineal rupture . It is quantitative studyusing a cross sectional approach, by using analysis of physiological maternity women  medical record data from January to April 2017 of 130 peoplein Trawas Public Health Center, Mojokerto Regency.The dataanalysis used was Chi - Square , indicated by p value = 0,000 with ɑ = 0,05. It means that the value of p <ɑ, so H1 is accepted. It can be concluded that there is a relationship between parity and the incidence of perineal rupture on physiological maternity women in Trawas Public Health Center,Mojokerto Regency. Midwives can apply collaboration with patients and their families to have physical and psychologicalpreparation with an alternative of hypnobirthing methods.


Author(s):  
Bibian Bibeca Bumbila García ◽  
Hernán Andrés Cedeño Cedeño ◽  
Tatiana Moreira Chica ◽  
Yaritza Rossana Parrales Ríos

The objective of the work is to establish the characterization of the auditory disability and its relationship with resilience at the Technical University of Manabí. The article shows a conceptual analysis related to the inclusion and social integration of disabled students. Based on the fact that the person with disabilities grows and develops in the same way as that of people without disabilities and what usually happens is that disabled people are rejected and discriminated against based on a prefabricated and erroneous conceptualization of these people. The results associated with the application of the SV-RES test prepared by the researchers are shown (Saavedra & Villalta, 2008b). Characterization of the auditory deficit is made in the students, and the limitations that derive from it are pointed out. We analyze the particularities related to communication with students who have a hearing disability and resilience in this type of student, where some personal highlights that in this sense constitute an example of resilience. Finally, the results related to the study of the relationship between students' hearing disability and the level of resilience dimensions are shown.


Author(s):  
Michael C. Rea

This chapter provides a detailed characterization of the various meanings of the term “divine hiddenness,” carefully and rigorously articulates the version of the problem of divine hiddenness that has dominated contemporary philosophical discussion for the past twenty-five years, and then explains the relationship between that problem and the problem of evil.


2019 ◽  
Vol 15 (S359) ◽  
pp. 413-414
Author(s):  
María P. Agüero ◽  
Rubén Díaz ◽  
Mischa Schirmer

AbstractThis work is focused on the characterization of the Seyfert-2 galaxies hosting very large, ultra-luminous narrow-line regions (NLRs) at redshifts z = 0.2−0.34. With a space density of 4.4 Gcp−3 at z ∼ 0.3, these “Low Redshift Lyman-α Blob” (LAB) host galaxies are amongst the rarest objects in the universe, and represent an exceptional and short-lived phenomenon in the life cycle of active galactic nuclei (AGNs). We present the study of GMOS spectra for 13 LAB galaxies covering the rest frame spectral range 3700–6700 Å. Predominantly, the [OIII]λ5007 emission line radial distribution is as widespread as that of the continuum one. The emission line profiles exhibit FWHM between 300–700 Km s−1. In 7 of 13 cases a broad kinematical component is detected with FWHM within the range 600–1100 Km s−1. The exceptionally high [OIII]λ5007 luminosity is responsible for very high equivalent width reaching 1500 Å at the nucleus.


2021 ◽  
Vol 170 ◽  
pp. 302-314
Author(s):  
Adeyinka S. Yusuff ◽  
Aman K. Bhonsle ◽  
Jayati Trivedi ◽  
Dinesh P. Bangwal ◽  
Lok P. Singh ◽  
...  

Author(s):  
Livio Cricelli ◽  
Michele Grimaldi ◽  
Silvia Vermicelli

AbstractIn recent years, Open Innovation (OI) and crowdsourcing have been very popular topics in the innovation management literature, attracting significant interest and attention, and inspiring a rich production of publications. Although these two topics share common themes and address similar managerial challenges, to the best of our knowledge, there is no systematic literature review that digs deep into the intersection of both fields. To fill in this gap a joint review of crowdsourcing and OI topics is both timely and of interest. Therefore, the main objective of this study is to carry out a comprehensive, systematic, and objective review of academic research to help shed light on the relationship between OI and crowdsourcing. For this purpose, we reviewed the literature published on these two topics between 2008 and 2019, applying two bibliometric techniques, co-citation and co-word analysis. We obtained the following results: (i) we provide a qualitative analysis of the emerging and trending themes, (ii) we discuss a characterization of the intersection between OI and crowdsourcing, identifying four dimensions (strategic, managerial, behavioral, and technological), (iii) we present a schematic reconceptualization of the thematic clusters, proposing an integrated view. We conclude by suggesting promising opportunities for future research.


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