The COVID-19 pandemic is an unprecedented situation that influenced all aspects of society, including education. Millions of students found themselves adjusting to a new medium of mathematics ...instruction, not to mention the teachers who had to provide instruction through remote sources. Considering students’ diverse social, economic, and academic background, this study sought to examine teachers’ perspectives on factors that support or hinder how equity is attended to in mathematics during remote instruction and the extent it differed from practices utilized when instruction was provided in a face-to-face setting. We also sought to document teachers’ perspectives on how they attended to equity in mathematics to support students with language barriers. We interviewed nine teachers to explore their perspectives of factors that support or hinder equity in mathematics teaching and learning during remote instruction compared to face-to-face instruction and how they support the diverse needs (inclusive of language barriers) of students. There were salient factors in this study that supported or hindered equitable mathematics instruction, such as teachers’ beliefs, expectations for students, access to resources, students’ socioeconomic status, and language barriers. Hence, it is recommended that policymakers, school administrators, and teachers need to collaborate to systematically plan to ensure that all students have access to quality mathematics.
Hexagonal boron nitride (hBN) exhibits high thermal conductivity within the in-plane direction and significantly lower thermal conductivity in the cross-plane direction because of its anisotropic ...nature. When the texture properties of bulk hBN are strong, it is a potentially promising application area for the insulating heat spreaders and heat sinks. In this study, hBN was synthesized in situ with the spark plasma sintering (SPS) technique and the effects of sintering temperature on the orientation of hBN grains were investigated. The precursor was prepared by chemically reacting urea and boric acid in heat treatment at 850 °C. The hBN was produced using the previous precursor in a SPS at 1500, 1700, and 1900 °C. The samples were characterized using XRD, FTIR, SEM and Raman spectroscopy. The properties of the samples were further determined through measurements of density, DSC and thermal diffusivity. The hBN samples obtained through the SPS process have nano and micron-size grains. The hBN was highly crystalline and homogeneous, as determined by the XRD pattern, Raman spectra and Raman maps. The orientation of hBN grains has been revealed in the c-axis of hBN crystallites and was preferably arranged within a plane parallel to the SPS pressing direction. The hBN orientation preference index (IOP) value of −19925.5 at 1700 °C indicates the highest quality texture orientation. Increasing the temperature to 1900 °C decreased the orientation in the direction parallel to the pressing direction. The highest thermal conductivity calculated according to the thermal diffusivity perpendicular to the sintering pressure direction was 8.86 W m−1K−1 at 1900 °C.
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•With this method, hBN can be obtained with SPS.•The highest orientation was obtained with an IOP value of −19925.5 at 1700 °C.•This study, shows that highly oriented hBN textured ceramics can be synthesized in situ with SPS.•The hBN can act as a barrier for heat conduction.
Children start to develop number sense even well before they start the school. Developing number sense serves as an intermediate tool for learning conventional mathematics taught in schools. This ...number sense has three key areas: number knowledge, counting and arithmetic operations. As a result, the aim of this study was to examine aged related complexity of number sense development of young children's aged four, six and seven under two key areas: number knowledge and counting. Semi structured task based clinical interviews were employed to examine number sense development. Five different assessment tasks were employed with three children. Children's responses were analysed to identify their level of number sense understanding and difficulties with developing number sense. Findings were reported under two categories: first children's ability to understand number concept and their ability to accomplish number word sequences and second counting. Findings of the study indicated a significant age related complexity and improvement in both two aspects of number sense. Older children with more experience developed better number sense than the younger children.
Children start to develop number sense even well before they start the school. Developing number sense serves as an intermediate tool for learning conventional mathematics taught in schools. This ...number sense has three key areas: number knowledge, counting and arithmetic operations. As a result, the aim of this study was to examine aged related complexity of number sense development of young children’s aged four, six and seven under two key areas: number knowledge and counting. Semi structured task based clinical interviews were employed to examine number sense development. Five different assessment tasks were employed with three children. Children’s responses were analysed to identify their level of number sense understanding and difficulties with developing number sense. Findings were reported under two categories: first children’s ability to understand number concept and their ability to accomplish number word sequences and second counting. Findings of the study indicated a significant age related complexity and improvement in both two aspects of number sense. Older children with more experience developed better number sense than the younger children.
In this study, the relationship between machinability, mechanical properties and microstructure of hBN-SiC composites was investigated. Manufacturing of the composites started with the calcination of ...raw materials at 850 °C for 16 h under a nitrogen atmosphere prior to mixing with 5 wt% of Al2O3:Y2O3 sintering additives and then powder mixtures were spark plasma sintered at 1850 °C for 17 min by applying 50 MPa pressure. Characterizations of the samples were carried out with FTIR, XRD, SEM and TEM methods. The physical and mechanical properties of the samples were determined with density measurement, Vickers hardness, Young's modulus, three-point bending, fracture toughness and drill test methods. The amount of in-situ formed hBN phase within the sintered composites was calculated by using the Rietveld method. The physical, mechanical and machinability properties of the composite were evaluated according to the calculated amount of hBN. The highest drilling speed during the test was obtained as 34.24 mm/min for the sample containing 29 wt% of hBN. Increasing the drill load from 19.61 N to 49.03 N resulted in 4.33 times increase in the drilling rate. TEM and STEM studies which were carried out for the microstructural investigations showed the internal defects as delamination bands within hBN phase formed during sintering. In addition to these analyses, novel precession electron diffraction method in TEM was utilized for orientation mapping to investigate any possible orientation relationship between SiC and in-situ synthesized hBN phase.
Bu çalışmada hekzagonal bor nitrür- silisyum
karbür (hBN-SiC) kompozit sentezinde sıcaklığın SiC tane boyutu üzerine etkisi
araştırılmıştır. Numunelerin SPS ile
1700oC, 1800oC, 1900oC ve 2000oC’de
...farklı sıcaklıklarda 50MPa basınç altında 15dak sinterleme işlemi
gerçekleştirilmiştir. Sinterleme sıcaklığının SiC tane boyutu üzerine etkisinin
belirlenmesi için İmageJ programı ile tane boyut ölçümleri gerçekleştirilerek normal dağılım fonksiyonu ile
tane boyut dağılımları tespit edilmiştir. 1700oC’den 1900oC’ye
sıcaklık artırıldığında h-BN miktarında %0,9’luk bir artış gözlenmiştir ve 2000oC’de
ise değişmemiştir. SiC ortalama tane boyutu 1700oC’den 2000oC’ye
sıcaklık artırıldığında 1,09µm’den 1,96µm’ye artmıştır. Tane boyut
dağılımlarının standart sapma değerleri ise 1700oC’de 0,445 iken
2000oC’de 0,812 değerine arttığı gözlenmiştir. Sıcaklığa bağlı olarak
tane boyut dağılımı artmaktadır. hBN
fazının güçlü kovalent bağları ve plaka şeklinde yapıya sahip olmasından dolayı
hBN’nin zayıf sinterlenebilitesi nedeniyle SiC tane büyümesini yavaşlattığı
söylenebilir.
SiC kovalent bağlı sert bir malzeme olmasından dolayı karmaşık şekillerin üretimi ve işlenebilirliği oldukça zor ve pahalıdır. Bu çalışmada hekzagonal bor nitrürün işlenebilirlik özelliğinden ...faydalanarak SiC’e daha kolay şekil verebilmek ve özellikleri geliştirmek için hBN-SiC kompozit üretimi araştırılmıştır. α-SiC tozların yüzeyi H3BO3 ve CO(NH2)2 kimyasal reaksiyonu ile hBN partikülleri ile kaplanarak hBN-SiC kompozit tozlar üretilmiş, kalsinasyon yapılmış ve SPS yöntemi ile şekillendirilip sinterlenerek hBN-SiC kompozit elde edilmiştir. Borik asit : üre oranları ve kalsinasyon süreleri değiştirilerek kompozit toz üretimine etkisi araştırılmıştır. Al2O3-Y2O3 ilavesi ile SPS’de sinterleme yapılarak mikroyapı, fiziksel ve mekanik özelliklerdeki değişimler belirlenmiştir. Sinterleme sıcaklığına bağlı olarak SiC tane büyümesinin aktivasyon enerjisi hesaplanmış ve hBN miktarının SiC tane büyümesine etkisi tespit edilmiştir. hBN-SiC kompozitlerin kırılma davranışı, işlenebilirlik özelliği incelenmiş ve aşınma testleri yapılmıştır. Üre miktarının ve kalsinasyon sürelerinin hBN oluşumunu etkilediği belirlenmiştir. hBN-SiC kompozitte artan hBN miktarı ile fiziksel ve mekanik özelliklerde azalma, daha hızlı işlenebilirlik ve yüzey aşınmasının arttığı tespit edilmiştir.
To determine the patient safety culture among nurses working at intensive care units.
This descriptive study was conducted at intensive care units of Health Practice and Research Center of Erciyes ...University and Kayseri Education and Research Hospital in the city center of Kayseri in Turkey. Three hundred sixteen nurses working at intensive care units at these hospitals were included in the study. Data were collected by using Hospital Survey on Patient Safety Culture (HSOPSC), developed by Agency for Healthcare Research and Quality. Percentage distribution and Mann Whitney U Test were used to analyze the data.
About 13.6% of the nurses working at intensive care units stated that they faced incidents of potential threat to the patient safety and that 48.8% of these cases were falls. Although a great majority of the nurses (88%) indicated that they never documented a case report, they assessed the patient safety in their institution as acceptable (43%). Out of the 12 dimensions of Hospital Survey on Patient Safety Culture, the percentage of positive responses was the highest for "teamwork within units" dimension and lowest for the "non-punitive response to error" dimension.
Awareness of the nurses regarding patient safety should be raised and their related knowledge should be kept up-to-date through more frequent in-service trainings.
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