Aldrin Jan Tabuso - Academia.edu (original) (raw)

Papers by Aldrin Jan Tabuso

Research paper thumbnail of A historical record of the impact of nuclear activities based on 129I in coral cores in Baler, Philippines: An update

Journal of environmental radioactivity, 2020

In a previous study in 2016, we presented how 129I in coral cores from the east (Baler) and west ... more In a previous study in 2016, we presented how 129I in coral cores from the east (Baler) and west (Parola) sides of the Philippines recorded the impacts of human nuclear activities, including nuclear weapons testing, nuclear fuel reprocessing, and nuclear accidents. However, the 2016 Baler dataset only had a two-year time resolution and a crude age model based on growth band counting. Here we present a new 2020 Baler 129I/127I atomic ratio dataset that features at least annual time resolution and a more accurate age model constructed using 3D X-ray Computed Tomography. Results show that the bomb peaks in Baler primarily came from the Pacific Proving Grounds or PPG with a time lag of about 1.8 years (or more specifically, between 1.3 and 2.4 years). Moreover, a review of the Parola dataset shows that PPG signals may have been transported to Parola in the West Philippine Sea via two pathways: the northward and southward bifurcations of the North Equatorial Current, reaching Parola abou...

Research paper thumbnail of 3D X-ray computed tomography gray value and age model datasets of coral cores Baler 2 and 3 (Philippines)

Data in Brief, 2021

The datasets here contain the 3D X-ray computed tomography (3DXCT) gray values and age models of ... more The datasets here contain the 3D X-ray computed tomography (3DXCT) gray values and age models of coral cores Baler 2 and 3, taken from Baler, Aurora, Philippines. 3DXCT was used to analyze 5 mm-thick slabs of the coral cores. From the resulting 3DXCT images, gray values were determined per pixel from top to bottom of the slabs. The gray value profiles across the length of the slabs were then matched with records of sea surface temperature (SST) of the Baler site to construct the age model of the coral cores. Daily SST records from October 2018 to February 1982 were from the Optimum Interpolation Sea Surface Temperature or OISST [1,2], while monthly SST records from February 1982 to May 1945 were from the Extended Reconstructed Sea Surface Temperature or ERSST [3]. The gray value datasets of coral cores Baler 2 and 3 present historical records of the corals' response to changing environments through the years and may be used in studies related to such. An example of this can be s...

Research paper thumbnail of Heat Treatment of 1045 and 4140 Steel

Steel is an iron alloy which comes in different compositions and with different properties to pro... more Steel is an iron alloy which comes in different compositions and with different properties to properly suit its intended use. Aside from the components of steel, heat treatment also affects the properties of the metal. It generally refers to the processes modifying the microstructure of a solid metal without phase change. Quenching, the heating of metal at a certain temperature then rapidly cooling it aiming to increase its hardness, and tempering, the heating of metal after quenching to restore its ductility, are just some of the heat treatment processes. For the experiment, 1045 and 4140 steels were used for quenching with water, oil, air cooling , and oil cooling to investigate its effects on the metal properties. For tempering, 1045 steel was tempered at 300 o C and 500 o C for 10, 20, 35, 55, and 80 mins. The experiment concluded that the quenchant affects the rate of cooling of the material which also affects the transformation of microstructure; hence, modifying the hardness of the steel. The tempering experiment, however, was unsuccessful to show the effects of temperature and time due to the unexpected behavior of the gathered data.

Research paper thumbnail of A historical record of the impact of nuclear activities based on 129I in coral cores in Baler, Philippines: An update

Journal of environmental radioactivity, 2020

In a previous study in 2016, we presented how 129I in coral cores from the east (Baler) and west ... more In a previous study in 2016, we presented how 129I in coral cores from the east (Baler) and west (Parola) sides of the Philippines recorded the impacts of human nuclear activities, including nuclear weapons testing, nuclear fuel reprocessing, and nuclear accidents. However, the 2016 Baler dataset only had a two-year time resolution and a crude age model based on growth band counting. Here we present a new 2020 Baler 129I/127I atomic ratio dataset that features at least annual time resolution and a more accurate age model constructed using 3D X-ray Computed Tomography. Results show that the bomb peaks in Baler primarily came from the Pacific Proving Grounds or PPG with a time lag of about 1.8 years (or more specifically, between 1.3 and 2.4 years). Moreover, a review of the Parola dataset shows that PPG signals may have been transported to Parola in the West Philippine Sea via two pathways: the northward and southward bifurcations of the North Equatorial Current, reaching Parola abou...

Research paper thumbnail of 3D X-ray computed tomography gray value and age model datasets of coral cores Baler 2 and 3 (Philippines)

Data in Brief, 2021

The datasets here contain the 3D X-ray computed tomography (3DXCT) gray values and age models of ... more The datasets here contain the 3D X-ray computed tomography (3DXCT) gray values and age models of coral cores Baler 2 and 3, taken from Baler, Aurora, Philippines. 3DXCT was used to analyze 5 mm-thick slabs of the coral cores. From the resulting 3DXCT images, gray values were determined per pixel from top to bottom of the slabs. The gray value profiles across the length of the slabs were then matched with records of sea surface temperature (SST) of the Baler site to construct the age model of the coral cores. Daily SST records from October 2018 to February 1982 were from the Optimum Interpolation Sea Surface Temperature or OISST [1,2], while monthly SST records from February 1982 to May 1945 were from the Extended Reconstructed Sea Surface Temperature or ERSST [3]. The gray value datasets of coral cores Baler 2 and 3 present historical records of the corals' response to changing environments through the years and may be used in studies related to such. An example of this can be s...

Research paper thumbnail of Heat Treatment of 1045 and 4140 Steel

Steel is an iron alloy which comes in different compositions and with different properties to pro... more Steel is an iron alloy which comes in different compositions and with different properties to properly suit its intended use. Aside from the components of steel, heat treatment also affects the properties of the metal. It generally refers to the processes modifying the microstructure of a solid metal without phase change. Quenching, the heating of metal at a certain temperature then rapidly cooling it aiming to increase its hardness, and tempering, the heating of metal after quenching to restore its ductility, are just some of the heat treatment processes. For the experiment, 1045 and 4140 steels were used for quenching with water, oil, air cooling , and oil cooling to investigate its effects on the metal properties. For tempering, 1045 steel was tempered at 300 o C and 500 o C for 10, 20, 35, 55, and 80 mins. The experiment concluded that the quenchant affects the rate of cooling of the material which also affects the transformation of microstructure; hence, modifying the hardness of the steel. The tempering experiment, however, was unsuccessful to show the effects of temperature and time due to the unexpected behavior of the gathered data.