ANALISA SIFAT FISIK DAN SIFAT KIMIA MATERIAL BATANG KULIT POHON SAGU (CORTEX METROXYLON SAGO) SEBAGAI MATERIAL ALTERNATIF BANGUNAN KAPAL

Material kayu banyak digunakan dalam pembuatan kapal kayu serta bagian interior kapal baja atau kapal fiberglass. Material kayu yang digunakan untuk konstruksi kapal haruslah memenuhi syarat kualifikasi (Biro Klasifikasi Indonesia) dengan kategori kelas kuat dan kelas awet sehingga dapat digunakan pada bagian konstruksi serata badan kapal. Dewasa ini pemakaian kebutuhan kayu untuk keperluan struktur dalam jumlah besar dengan kualitas tinggi semakin sulit diperoleh. Hal ini menyebabkan harga kayu untuk keperluan material kapal sangat tinggi. Sehingga diperlukan material alternatif dalam membangun kapal kayu. Material Batang Kulit Pohon Sagu sejak jaman primitif telah digunakan pada kapal yang sederhana atau bagian interior konstruksi kapal namun material ini belum dikaji secara teknik. Potensi Pohon Sagu oleh masyarakat lokal masih sebatas memanfaatkan pati sagunya sebagai bahan makan pokok dan daunnya sebagai atap rumah, sedangkan Batang Kulit Pohon Sagu tidak dimanfaatkan dan dibiarkan sebagai limbah hasil pengolahan sagu. Penelitian ini bertujuan untuk menentukan kelas awet dan kelas kuat material Batang Kulit Pohon Sagu berdasarkan analisa sifat kimia dan sifat mekanis material Limbah Batang Kulit Pohon Sagu. Hasil penelitian diperoleh nilai rata-rata kadar air berkisar antara 5,13% - 6,89%, Rata-rata Berat Jenis material Limbah Batang Kulit Pohon Sagu berkisar antara 0,86 kg/m3.Pengujian tarik (Tensile Test) dan pengujian Tekan (Compressive Test) mengunakan pengujian standard ASTM D 3039/3039 M dan ASTM D 3410/3410M. Kekuatan tarik rata-rata dari kelima jenis Pohon Sagu yang tersebar di Provinsi Maluku adalah 1019 kg/cm2 – 1101,29 kg/cm2, kekuatan tekan rata-rata adalah 458,87 kg/cm2 – 520,05 kg/cm2. Dengan demikian material Batang Kulit Pohon Sagu masuk dalam kualifikasi Kelas Kuat II menurut standard BKI untuk Kapal Kayu.Penentuankelas awet yang dilakukan dengan menggunakan prosedur standar SNI 01-7207-2006 tentang uji ketahanan kayu dan produkkayu terhadap organisme perusak kayu dilaut dengan rata-rata intesitas serangan sebesar 16%. Namun kelemahan dari material ini adalah ketebalan Batang Kulit Pohon Sagu yang berkisar antara 1 cm – 2 cm sehingga harus dilakukan rekayasa model untuk mendapatkan bentuk profil sesuai dengan ketebalan profil pada bangunan kapal

RAN-related neural-congruency: a machine learning approach toward the study of the neural underpinnings of naming speed

ObjectiveNaming speed, behaviorally measured via the serial Rapid automatized naming (RAN) test, is one of the most examined underlying cognitive factors of reading development and reading difficulties (RD). However, the unconstrained-reading format of serial RAN has made it challenging for traditional EEG analysis methods to extract neural components for studying the neural underpinnings of naming speed. The present study aims to explore a novel approach to isolate neural components during the serial RAN task that are (a) informative of group differences between children with dyslexia (DYS) and chronological age controls (CAC), (b) improve the power of analysis, and (c) are suitable for deciphering the neural underpinnings of naming speed.MethodsWe propose a novel machine-learning-based algorithm that extracts spatiotemporal neural components during serial RAN, termed RAN-related neural-congruency components. We demonstrate our approach on EEG and eye-tracking recordings from 60 children (30 DYS and 30 CAC), under phonologically or visually similar, and dissimilar control tasks.ResultsResults reveal significant differences in the RAN-related neural-congruency components between DYS and CAC groups in all four conditions.ConclusionRapid automatized naming-related neural-congruency components capture the neural activity of cognitive processes associated with naming speed and are informative of group differences between children with dyslexia and typically developing children.SignificanceWe propose the resulting RAN-related neural-components as a methodological framework to facilitate studying the neural underpinnings of naming speed and their association with reading performance and related difficulties

The Physics of the B Factories

This work is on the Physics of the B Factories. Part A of this book contains a brief description of the SLAC and KEK B Factories as well as their detectors, BaBar and Belle, and data taking related issues. Part B discusses tools and methods used by the experiments in order to obtain results. The results themselves can be found in Part C

Expanding horizons of cross-linguistic research on reading: The Multilingual Eye-movement Corpus (MECO)

Scientific studies of language behavior need to grapple with a large diversity of languages in the world and, for reading, a further variability in writing systems. Yet, the ability to form meaningful theories of reading is contingent on the availability of cross-linguistic behavioral data. This paper offers new insights into aspects of reading behavior that are shared and those that vary systematically across languages through an investigation of eye-tracking data from 13 languages recorded during text reading. We begin with reporting a bibliometric analysis of eye-tracking studies showing that the current empirical base is insufficient for cross-linguistic comparisons. We respond to this empirical lacuna by presenting the Multilingual Eye-Movement Corpus (MECO), the product of an international multi-lab collaboration. We examine which behavioral indices differentiate between reading in written languages, and which measures are stable across languages. One of the findings is that readers of different languages vary considerably in their skipping rate (i.e., the likelihood of not fixating on a word even once) and that this variability is explained by cross-linguistic differences in word length distributions. In contrast, if readers do not skip a word, they tend to spend a similar average time viewing it. We outline the implications of these findings for theories of reading. We also describe prospective uses of the publicly available MECO data, and its further development plans

Text reading in English as a second language: Evidence from the Multilingual Eye-Movements Corpus

Research into second language (L2) reading is an exponentially growing field. Yet, it still has a relatively short supply of comparable, ecologically valid data from readers representing a variety of first languages (L1). This article addresses this need by presenting a new data resource called MECO L2 (Multilingual Eye Movements Corpus), a rich behavioral eye-tracking record of text reading in English as an L2 among 543 university student speakers of 12 different L1s. MECO L2 includes a test battery of component skills of reading and allows for a comparison of the participants' reading performance in their L1 and L2. This data resource enables innovative large-scale cross-sample analyses of predictors of L2 reading fluency and comprehension. We first introduce the design and structure of the MECO L2 resource, along with reliability estimates and basic descriptive analyses. Then, we illustrate the utility of MECO L2 by quantifying contributions of four sources to variability in L2 reading proficiency proposed in prior literature: reading fluency and comprehension in L1, proficiency in L2 component skills of reading, extralinguistic factors, and the L1 of the readers. Major findings included (a) a fundamental contrast between the determinants of L2 reading fluency versus comprehension accuracy, and (b) high within-participant consistency in the real-time strategy of reading in L1 and L2. We conclude by reviewing the implications of these findings to theories of L2 acquisition and outline further directions in which the new data resource may support L2 reading research

Maximizing and stabilizing luminescence from halide perovskites with potassium passivation

Metal halide perovskites are of great interest for various high-performance optoelectronic applications. The ability to tune the perovskite bandgap continuously by modifying the chemical composition opens up applications for perovskites as coloured emitters, in building-integrated photovoltaics, and as components of tandem photovoltaics to increase the power conversion efficiency. Nevertheless, performance is limited by non-radiative losses, with luminescence yields in state-of-the-art perovskite solar cells still far from 100 per cent under standard solar illumination conditions. Furthermore, in mixed halide perovskite systems designed for continuous bandgap tunability2 (bandgaps of approximately 1.7 to 1.9 electronvolts), photoinduced ion segregation leads to bandgap instabilities. Here we demonstrate substantial mitigation of both non-radiative losses and photoinduced ion migration in perovskite films and interfaces by decorating the surfaces and grain boundaries with passivating potassium halide layers. We demonstrate external photoluminescence quantum yields of 66 per cent, which translate to internal yields that exceed 95 per cent. The high luminescence yields are achieved while maintaining high mobilities of more than 40 square centimetres per volt per second, providing the elusive combination of both high luminescence and excellent charge transport. When interfaced with electrodes in a solar cell device stack, the external luminescence yield—a quantity that must be maximized to obtain high efficiency—remains as high as 15 per cent, indicating very clean interfaces. We also demonstrate the inhibition of transient photoinduced ion-migration processes across a wide range of mixed halide perovskite bandgaps in materials that exhibit bandgap instabilities when unpassivated. We validate these results in fully operating solar cells. Our work represents an important advance in the construction of tunable metal halide perovskite films and interfaces that can approach the efficiency limits in tandem solar cells, coloured-light-emitting diodes and other optoelectronic applications.M.A.-J. thanks Nava Technology Limited and Nyak Technology Limited for their funding and technical support. Z.A.-G. acknowledges funding from a Winton Studentship, and ICON Studentship from the Lloyd’s Register Foundation. This project has received funding from the European Union’s Seventh Framework Programme (FP7/2007-2013) under REA grant agreement number PIOF-GA-2013-622630, the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement number 756962), and the Royal Society and Tata Group (UF150033). We thank the Engineering and Physical Sciences Research Council (EPSRC) for support. XMaS is a mid-range facility at the European Synchrotron Radiation Facility supported by the EPSRC and we are grateful to the XMaS beamline team staff for their support. We thank Diamond Light Source for access to beamline I09 and staff member T.-L. Lee as well as U. Cappel for assistance during the HAXPES measurements. S.C., C.D. and G.D. acknowledge funding from the ERC under grant number 25961976 PHOTO EM and financial support from the European Union under grant number 77 312483 ESTEEM2. M.A. thanks the president of the UAE’s Distinguished Student Scholarship Program, granted by the Ministry of Presidential Affairs. H.R. and B.P. acknowledge support from the Swedish research council (2014-6019) and the Swedish foundation for strategic research. E.M.H. and T.J.S. were supported by the Netherlands Organization for Scientific Research under the Echo grant number 712.014.007