684 research outputs found
Fatigue performance of thermal spray coatings on carbon steel: a review
This paper contributes to a review of the research of the fatigue behaviour of thermal spray coatings on carbon steel. Previous studies provide the experimental characterization of the fatigue resistance of coated carbon steel. Different coating powders were deposited to a different type of carbon steels. Also, S-N curves were drawn from axial- and rotating bending fatigue test to determine the fatigue strength or fatigue limit of the samples. Thermal spray coatings showed great improvement to the work hardening effect but worsen the fatigue life due to the inclusion of oxide and pores, the presence of stress concentrators, and high microcrack density. Moreover, the effects of the surrounding environment have also resulted in pros and cons towards the fatigue strength. An improvement, however, can be done with the shot peening treatment, which significantly increases the compressive residual stress at interfaces of coating/substrate. The high compressive residual stress could delay the crack nucleation, thus increasing the fatigue life of the coated part
Teaching and Learning in Interdisciplinary Higher Education: A Systematic Review
Interdisciplinary higher education aims to develop boundary-crossing skills, such as interdisciplinary thinking. In the present review study, interdisciplinary thinking was defined as the capacity to integrate knowledge of two or more disciplines to produce a cognitive advancement in ways that would have been impossible or unlikely through single disciplinary means. It was considered as a complex cognitive skill that constituted of a number of subskills. The review was accomplished by means of a systematic search within four scientific literature databases followed by a critical analysis. The review showed that, to date, scientific research into teaching and learning in interdisciplinary higher education has remained limited and explorative. The research advanced the understanding of the necessary subskills of interdisciplinary thinking and typical conditions for enabling the development of interdisciplinary thinking. This understanding provides a platform from which the theory and practice of interdisciplinary higher education can move forwar
Interdisciplinary thinking in agricultural and life sciences higher education
Interdisciplinary thinking as a skill appears to be of value to higher education students and those in employment. This idea is explored with reference to the agricultural and life sciences. The need for further understanding of the development of interdisciplinary thinking is acknowledged. This is closely related to the requirement for well-founded curriculum and course design. This publication presents a brief introduction to a systematic review of scientific research into teaching and learning in interdisciplinary higher education. While tentative, the understanding arising from the review findings is considered to be of potential value to educational practice. A selection of the review findings is presented by way of illustration. The selection is believed to be of relevance to the agricultural and life sciences. The review findings presented here take the form of interdisciplinary thinking sub skills and enabling condition
Pengaruh Optimasi Transformator Daya terhadap Perkembangan Beban Feeder untuk Meminimalisasi Gangguan dan Defisit Beban Listrik di Wilayah Sorong-provinsi Papua Barat
Efisiensi suatu transformator antara lain ditentukan oleh besarnya beban yang meningkat baik dari bulan ke bulan maupun dari tahun ke tahun. Beban tersebut memberikan masukan kepada gardu induk sehubungan dengan kapasitasnya, sehingga akan dapat ditentukan apakah gardu induk tersebut masih mampu menanggung beban yang meningkat tersebut. Oleh karena itu diperlukan suatu penelitian mengenai optimalisasi efisiensi transformator yang ada di gardu induk Sorong, sehingga hasil dari penelitian ini dapat menentukan efisiensi transformator yang optimal sesuai dengan perkembangan beban yang akan datang. Dengan cara mengestimasi beban yang akan datang yang berupa arus (Ampere) di sisi sekunder, maka arus (Ampere) di sisi primer dapat diketahui, sehingga daya masukan (Watt) di sisi primer dan daya keluaran (Watt) di sisi sekunder dapat ditentukan.Jadi rugi-rugi transformator dapat diketahui. Dengan diketahui daya masukan, daya keluaran, rugi-rugi transformator, maka efisiensi transformator dapat ditentukan. Dari hasil estimasi beban diperoleh juga beberapa efisiensi, sehingga dapat ditentukan kapan optimal efisiensi tersebut akan terjadi terhadap perkembangan beban yang akan datang
Populations of Pear Thrips, \u3ci\u3eTaeniothrips Inconsequens\u3c/i\u3e (Thysanoptera: Thripidae) in Sugar Maple Stands in Vermont: 1989-2005
Development of an effective IPM strategy for pear thrips, Taeniothrips inconsequens (Uzel) (Thysanoptera: Thripidae), a pest of sugar maple, Acer saccharum Marshall, demands an understanding of their population fluctuations over time. Pear thrips populations were monitored using a standardized soil sampling method every fall from 1989 – 2005 in 14 counties of Vermont (U.S.). Data from individual sites were combined into north, central and south regions. High numbers of thrips emerged from soil sampled in 1989, 1990, 1993 and 2001, particularly in the north region (Washington, Lamoille, and Franklin counties). The central and south regions had lower pear thrips populations over all years. These results provide, for the first time, fundamental knowledge of pear thrips populations across a wide geographical area of Vermont and will assist in the design of suitable control strategies for pear thrips in the future
Online discussion compensates for suboptimal timing of supportive information presentation in a digitally supported learning environment
This study used a sequential set-up to investigate the consecutive effects of timing of supportive information presentation (information before vs. information during the learning task clusters) in interactive digital learning materials (IDLMs) and type of collaboration (personal discussion vs. online discussion) in computer-supported collaborative learning (CSCL) on student knowledge construction. Students (N = 87) were first randomly assigned to the two information presentation conditions to work individually on a case-based assignment in IDLM. Students who received information during learning task clusters tended to show better results on knowledge construction than those who received information only before each cluster. The students within the two separate information presentation conditions were then randomly assigned to pairs to discuss the outcomes of their assignments under either the personal discussion or online discussion condition in CSCL. When supportive information had been presented before each learning task cluster, online discussion led to better results than personal discussion. When supportive information had been presented during the learning task clusters, however, the online and personal discussion conditions had no differential effect on knowledge construction. Online discussion in CSCL appeared to compensate for suboptimal timing of presentation of supportive information before the learning task clusters in IDLM
Studi Perencanaan Pembangunan Pltmh di Kampung Sasnek Distrik Sawiat Kabupaten Sorong Selatan Provinsi Papua Barat
Listrik sangat dibutuhkan oleh seluruh lapisan masyarakat. Kampung Sasnek merupakan salah satu kampung yang terletak di Distrik Sawiat Kabupaten Sorong Selatan Provinsi Papua Barat. Kampung sasnek letaknya sangat terpencil dan dihuni sekitar 100KK. Kampung ini belum terlayani listrik oleh PLN hingga saat ini. Pembangkit listrik mikro hidro adalah pembangkit listrik skala kecil yang kapasitasnya berkisar antara 100 W sampai dengan 100 kW. Studi perencanaan ini bertujuan merencanakan dan nantinya akan ke tahap implementasi Pembangkit Listrik mikro hidro dengan kapasitas daya 12 Volt DC, karena merupakan salah satu cara pembangkit listrik yang paling ekonomis, muda dan aman. pengukuran debit air, didapat debit sebesar 2 liter/detik dari luas area pengukuran 5 m2 dan kecepatan air rata-rata 00.65 m/d. Namun karena kondisi air sungai yang mengalir sepanjang tahun dalam arti tidak pernah kering, maka digunakan faktor koreksi 0.75. Dengan demikian debit yang bisa dimanfaatkan adalah sebesar 0.65 m3/d. Berdasarkan hasil analisa terhadap potensi PLTMH yang terdapat di Sasnek, maka dapat dikalkulasikan Distribusi Jaringan Listrik yang bersumber dari PLTMH Sasnek adalah 10 KW. Dengan adanya perencanaan yang matang sehingga hasil implementasinya akan memberikan dampak yang postif akan pemenuhan kebutuhan listrik di kampung sasnek dan juga kampung sekitarnya
A Team-Based Service Model: Mann Library, Cornell University
Mann Library began piloting a new team-based service model in August 2019 to replace the liaison model. By separating into teams of instruction or research support and removing departmental outreach from individual librarian responsibilities, Mann librarians have been able to prioritize their functional areas of expertise that were increasing in demand and devote more time to innovative new projects. We have begun our assessment of the new model which will continue through 2020, but we are also taking an iterative approach as we implement these changes, gathering feedback from staff and course correcting as necessary
Evaluation of the Practicum at College of Arts and Sciences - University of Nizwa
The purpose of this study was to evaluate the practicum at University of Nizwa. The study identified the necessary skills that were acquired by student-teachers attributed through the practicum. It also aimed to identify whether there were significant differences in the evaluation of practicum due to the variable of program. The instrument used in the study consisted of 66 items. The samples of the study consisted of (48) student-teachers who were enrolled in the practicum at the college of arts and science at the University of Nizwa during the academic year 2014/2015. The results revealed that the level of evaluation of practicum was high and positive in general. Flaming of teaching, classroom management, then evaluation and feedback domains were the highest
The influence of welding condition on the microstructure of WC hardfacing coating on carbon steel substrate
Tungsten carbide (WC) hardfacing coating technique is widely used to improve the performance of carbon steel blade exposed to acidic and abrasive conditions during production. This paper deals with the influence of welding parameters on the microstructure and carbide distribution of WC. WC hardfacing was deposited onto carbon steel by shielded metal arc welding (SMAW). Welding parameters such as welding current, number of weld layers, electrode drying and base material preheat were the focus of this work. Coating hardness, microstructure and elemental composition were analysed in detail. The effects of the welding parameters on WC hardfacing coating microstructure and hardness value were characterized by scanning electron microscope (SEM) and micro-Vickers hardness tester respectively. The larger carbide growth in overall coating region is mainly dictated by high current (200 A), increased number of weld layers (3 layers) and presence of base material preheat due to sufficient heat energy initiating carbide growth. The investigation also revealed that high current affected the growth of smaller carbide particles in matrix region significantly. Meanwhile, number of weld layers and base material preheat influences were seen during hardfacing with lower welding current. The absence of electrode drying led to uniform smaller carbide distribution in matrix region. It was found that increased number of large carbides and uniformly distributed smaller carbides in WC hardfacing deposit increased the hardness value of the coating
- …