Search

Your search keyword '"Lau, Deborah"' showing total 37 results
Start Over Author "Lau, Deborah"
37 results on '"Lau, Deborah"'

10. REVIEW : Identifikasi Senyawa Tanin Pada Tumbuhan Rambutan

Author

Zahra, Aliya Azkia, Lau, Deborah Chennia, Wahyudi, Najla Yusiana, Nanda, Asri Yuniar Dwi, Nibullah, Salsabila Granadha, and Mierza, Vriezka

Abstract

Rambutan (Nephelium lappaceum L.) adalah salah satu tanaman yang sering dijumpai di Indonesia, karena tanaman ini tumbuh pada daerah beriklim tropis. Banyak sekali manfaatnya khususnya untuk mengobati penyakit-penyakit dengan cara tradisional. Metabolit sekunder yang terkandung pada daun rambutan antara lain ada steroid, flavonoid, saponin dan tanin. Metabolit sekunder itu sendiri didefinisikan dengan senyawa yang dihasilkan dari sebuah tanaman yang memiliki peran biologis dan ekologi. Umumnya, tanaman yang terkandung metabolit sekunder di dalamnya biasanya memiliki fungsi yaitu sebagai obat, seperti pada tanaman rambutan ini memiliki beberapa manfaat untuk mengobati penyakit-penyakit secara tradisional. Metode yang dilakukan pada review jurnal ini dengan pencarian literatur, review jurnal ini bertujuan untuk mengetahui metabolit sekunder yang terkandung dalam tanaman rambutan, khususnya tanin. Tanin yang terkandung pada daun rambutan sendiri yaitu kelompok besar dari senyawa kompleks yang didistribusikan merata pada setiap tanaman, setiap famili tanaman hampir semua memiliki spesies yang mengandung tanin, tanin tak hanya terdapat di bagian daun tetapi ada juga di bagian tanaman yang spesifik lainnya yaitu pada buah, kulit, dahan, dan batang. Tanin memiliki fungsi mengikat dan mengendapkan protein, di dunia pengobatan, tanin memiliki fungsi untuk mengobati diare, menghentikan pendarahan, dan juga memiliki fungsi untuk mengobati ambeien serta berkhasiat sebagai antioksidan.

Published
2023
Full Text
View/download PDF

11. The Next Generation of MS2A Resin: MS3.

Author

Lau, Deborah, Saubern, Simon, Alexander, David L.J., Hutt, Oliver, and Villis, Carl

Abstract

Copyright of Journal of the American Institute for Conservation is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Published
2023
Full Text
View/download PDF

18. Raman spectroscopy of artists' materials: Advances in characterisation and analysis

Author

Lau, Deborah and Lau, Deborah

Abstract

Cultural heritage research and conservation practice seek to preserve our cultural heritage. Understanding the composition of the materials that comprise the artwork or cultural object is critical to inform collections management and preservation treatments; however methods of analysis are constrained to those that are either non-destructive or can obtain the desired information from micro-samples in order to retain the integrity of the object. Raman spectroscopy is an ideal technique for characterising cultural materials as it is non-destructive, requires relatively little sample preparation and utilises short measurement times. Micro-Raman is especially useful for examining micro-samples and painting cross sections due to its spatial resolution being sufficiently high to target individual pigment grains. Despite the non-destructive, micro-sample analysis advantages, there are limitations to the use of Raman spectroscopy in the cultural heritage conservation context. Firstly, fluorescence is frequently observed in cultural materials. Secondly, with the large number of compositionally complex and heterogenous materials encountered in conservation, there is a need for advanced methods that can deal with large sample datasets. These methods are needed to facilitate examination of both non-spatial data and spatial (imaging) data, to extract the maximum amount of information possible from the limited sample available. It is the aim of this thesis to demonstrate how Raman micro-spectroscopy can provide new and useful information about paintings using the following strategies. (1) Creation of a reliable pigment database supported by X-ray diffraction data to confirm the structural identity of each pigment. At the time this work was started, a spectral library for pigment identification was necessary to have a comprehensive set of pigment reference spectra against which to compare unknowns. A Raman spectral pigment reference library was developed comprising over 180 sample

Published
2020

20. Reimagining the future of plastics: With our oceans littered with trillions of pieces of rubbish, how do we solve the plastic pollution crisis?

Author

Lau, Deborah

Subjects
*PLASTIC scrap recycling, *PLASTIC marine debris, *WASTE management, *PLASTICS, *POLLUTION, *OCEAN, *BIODEGRADABLE plastics
Abstract

The article offers information on oceans has littered with trillions of pieces of rubbish, how do we solve the plastic pollution crisis. Topics include the billion tonnes of primary materials are extracted to meet global demand for plastic products, and the few signs of reprieve as global plastic production catapults towards an increase.

Published
2021

23. We need a global treaty to solve plastic pollution -- acid rain and ozone depletion show us why.

Author

Lau, Deborah

Subjects
ACID rain, OZONE layer depletion, POLLUTION, WASTE management, PLASTIC scrap
Abstract

The United Nations is working towards a global treaty on plastic pollution, drawing inspiration from past agreements on ozone layer depletion and acid rain. The goal of the treaty is to develop a legally binding agreement by 2024 that addresses the entire life cycle of plastics, including production, design, and disposal. Involving 175 nations, the treaty aims to transform plastic waste management and pave the way for new technologies and industries. Multilateral agreements, such as the Montreal Protocol and clean air legislation, have proven effective in driving change and innovation, and a global approach is necessary to tackle the problem of plastic pollution. [Extracted from the article]

Published
2023

26. High-Definition X-ray Fluorescence Elemental Mapping of Paintings

Author

Howard, Daryl L., primary, de Jonge, Martin D., additional, Lau, Deborah, additional, Hay, David, additional, Varcoe-Cocks, Michael, additional, Ryan, Chris G., additional, Kirkham, Robin, additional, Moorhead, Gareth, additional, Paterson, David, additional, and Thurrowgood, David, additional

Published
2012
Full Text
View/download PDF

35. Electron-Beam-Induced Carbon Contamination on Silicon: Characterization Using Raman Spectroscopy and Atomic Force Microscopy.

Author

Lau, Deborah, Hughes, Anthony E., Muster, Tim H., Davis, Timothy J., and Glenn, A. Matthew

Subjects
CARBON, SILICON, RAMAN spectroscopy, ATOMIC force microscopy, SCANNING electron microscopy, ELECTRON beams
Abstract

Electron-beam-induced carbon film deposition has long been recognized as a side effect of scanning electron microscopy. To characterize the nature of this type of contamination, silicon wafers were subjected to prolonged exposure to 15 kV electron beam energy with a probe current of ~300 pA. Using Raman spectroscopy, the deposited coating was identified as an amorphous carbon film with an estimated crystallite size of 125 Å. Using atomic force microscopy, the cross-sectional profile of the coating was found to be raised and textured, indicative of the beam raster pattern. A map of the Raman intensity across the coating showed increased intensity along the edges and at the corner of the film. The intensity profile was in excess of that which could be explained by thickness alone. The enhancement was found to correspond with a modeled local field enhancement induced by the coating boundary and showed that the deposited carbon coating generated a localized disturbance in the opto-electrical properties of the substrate, which is compared and contrasted with Raman edge enhancement that is produced by surface structure in silicon. [ABSTRACT FROM AUTHOR]

Published
2010
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results