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1.
Int J Biol Macromol ; 253(Pt 2): 126786, 2023 Dec 31.
Article in English | MEDLINE | ID: mdl-37690637

ABSTRACT

Rust powder collected from an archeological iron was evaluated by complementary analyses such as FTIR, XRD, XRF, and SEM/EDX. The analyses revealed that lepidocrocite (L) was the major component in the archeological iron. Coconut husk (CH) can be classified as a type of lignocellulosic biomass of renewable resources that are widely available, especially in coastal areas. In this research, the isolated lignin extracted from CH is being studied as a potential alternative for environmentally friendly applications. The isolated lignin from soda and organosolv pulping went through several analyses such as FTIR, NMR (13C and 2D-HSQC), and TGA analyses. The analyses showed that lignin isolated via soda pulping has superior antioxidant capabilities due to its greater phenolic-OH content compared to lignin isolated from organosolv pulping. The effects of lignin concentrations, pH, and reaction time were utilized in rust conversion studies of an archeological iron. 5 wt% of soda lignin (SL) was revealed as the ideal condition in this rust conversion study with a value of 84.21 %. The treated rust powder with 5 wt% of SL was then further gone through several complementary analyses, which revealed that the treated rust had nearly transformed into an amorphous state.


Subject(s)
Cocos , Lignin , Lignin/chemistry , Cocos/chemistry , Iron , Powders , Magnetic Resonance Spectroscopy
2.
Heliyon ; 9(4): e14850, 2023 Apr.
Article in English | MEDLINE | ID: mdl-37123952

ABSTRACT

Archaeological excavations carried out on 17 iron smelting workshops at the Sungai Batu Archaeological Complex have found the raw materials of iron industry (hematite, magnetite and geotite) with iron slag, tuyere, remains of furnace, and iron ingots. In order to obtain primary data related to the location of the raw materials of iron smelting obtained, the survey and mapping activities were carried out using geological maps and Sungai Petani maps around UiTM Merbok, Bukit Inas, Merbok, Batu 5 Village, Paya Suri Village and Ayer Nasi Hill, Semeling. The results of the iron ore survey were then subjected to scientific analysis to compare the mineral composition with the findings of iron ore at the iron smelting site. The results of X-Ray Fluorescence (XRF) analysis of iron ore for major elements reveal the elements silica oxide (SiO2), iron oxide (FeO₊), manganese oxide (MnO), calcium oxide (CaO), aluminum oxide (Al2O3) and titanium oxide (TiO2) as well as arsenic (As), Chlorine (Cl), copper (Cu), scandium (S), vanadium (V) and zinc (Zn) for trace elements clearly show the raw material of iron smelting in the Archaeological Complex Sungai Batu is from the same source. Based on the analysis of the raw materials of iron smelting to enable the iron smelting industry in the Archaeological Complex to take place is taken from a distance of 1-11 km from this complex.

3.
Malays J Med Sci ; 28(1): 1-8, 2021 Feb.
Article in English | MEDLINE | ID: mdl-33679214

ABSTRACT

Perak Man, named after the state where the skeleton was found, was the most complete skeleton found in Southeast Asia. The funerary artefacts indicate that Perak Man was highly respected, as he was buried at the centre of the highest cave in Lenggong, and he was the only person buried there. A copy of the original skull was made using computed tomography (CT) and 3D printing. Based on the internal structure of the reconstructed skull, the estimated intracranial volume (ICV) is 1,204.91 mL. The hypothetical face of Perak Man was reconstructed according to established forensic methods. Based on his presumed status, Perak Man was likely a respected person in the group and, perhaps, a shaman and the most knowledgeable person in the group regarding survival, hunting, gathering and other aspects of Palaeolithic daily life.

4.
Hum Genet ; 135(5): 587, 2016 May.
Article in English | MEDLINE | ID: mdl-27041535

ABSTRACT

In the original article, one of the co-authors' (Ken Khong Eng) given name has been published incorrectly. The correct given name should be Ken Khong. The original article has been corrected.

5.
Hum Genet ; 135(4): 363-376, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26875094

ABSTRACT

There has been a long-standing debate concerning the extent to which the spread of Neolithic ceramics and Malay-Polynesian languages in Island Southeast Asia (ISEA) were coupled to an agriculturally driven demic dispersal out of Taiwan 4000 years ago (4 ka). We previously addressed this question using founder analysis of mitochondrial DNA (mtDNA) control-region sequences to identify major lineage clusters most likely to have dispersed from Taiwan into ISEA, proposing that the dispersal had a relatively minor impact on the extant genetic structure of ISEA, and that the role of agriculture in the expansion of the Austronesian languages was therefore likely to have been correspondingly minor. Here we test these conclusions by sequencing whole mtDNAs from across Taiwan and ISEA, using their higher chronological precision to resolve the overall proportion that participated in the "out-of-Taiwan" mid-Holocene dispersal as opposed to earlier, postglacial expansions in the Early Holocene. We show that, in total, about 20% of mtDNA lineages in the modern ISEA pool result from the "out-of-Taiwan" dispersal, with most of the remainder signifying earlier processes, mainly due to sea-level rises after the Last Glacial Maximum. Notably, we show that every one of these founder clusters previously entered Taiwan from China, 6-7 ka, where rice-farming originated, and remained distinct from the indigenous Taiwanese population until after the subsequent dispersal into ISEA.


Subject(s)
Genomic Imprinting , Asia, Southeastern , DNA, Mitochondrial/genetics , Female , Founder Effect , Humans , Taiwan
6.
Proc Natl Acad Sci U S A ; 109(46): 18684-8, 2012 Nov 13.
Article in English | MEDLINE | ID: mdl-23112159

ABSTRACT

The Toba supereruption in Sumatra, ∼74 thousand years (ka) ago, was the largest terrestrial volcanic event of the Quaternary. Ash and sulfate aerosols were deposited in both hemispheres, forming a time-marker horizon that can be used to synchronize late Quaternary records globally. A precise numerical age for this event has proved elusive, with dating uncertainties larger than the millennial-scale climate cycles that characterized this period. We report an astronomically calibrated (40)Ar/(39)Ar age of 73.88 ± 0.32 ka (1σ, full external errors) for sanidine crystals extracted from Toba deposits in the Lenggong Valley, Malaysia, 350 km from the eruption source and 6 km from an archaeological site with stone artifacts buried by ash. If these artifacts were made by Homo sapiens, as has been suggested, then our age indicates that modern humans had reached Southeast Asia by ∼74 ka ago. Our (40)Ar/(39)Ar age is an order-of-magnitude more precise than previous estimates, resolving the timing of the eruption to the middle of the cold interval between Dansgaard-Oeschger events 20 and 19, when a peak in sulfate concentration occurred as registered by Greenland ice cores. This peak is followed by a ∼10 °C drop in the Greenland surface temperature over ∼150 y, revealing the possible climatic impact of the eruption. Our (40)Ar/(39)Ar age also provides a high-precision calibration point for other ice, marine, and terrestrial archives containing Toba sulfates and ash, facilitating their global synchronization at unprecedented resolution for a critical period in Earth and human history beyond the range of (14)C dating.

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