Research

As the national university, we champion and support innovative research that addresses the country’s most pressing challenges.

25 Mar 2025

Tracing Darna’s roots in Filipino folk culture challenges the typically male-centered Western superhero genre

Power is one of the most distinguishing features of the superhero genre. In this regard, one of the most recognizable...

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18 Mar 2025

UP Manila

The clustering of tuberculosis cases could be linked to the El Niño phenomenon

This study focused on tuberculosis (TB) cases in Region III of the Philippines for the years 2019, 2020, and 2021,...

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17 Mar 2025

Perceived factors to teenage pregnancy such as technological influence influence the manner of delivering services

Teenage pregnancy remains to be a major concern in the health of Filipino adolescents despite the nationwide adoption of sexual...

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07 Mar 2025

UP Open University

Research uncovers new information on the voice of the Philippine flat-headed frog found only in Palawan

This study describes the call of Barbourula busuangensis, a peculiar and elusive fully aquatic frog endemic to the Palawan archipelago of...

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07 Mar 2025

UP Manila

High levels of body association lowers the risk of depression, anxiety and stress among Filipino emerging adults

Among Filipino emerging adults, prevalence rates of severe and extreme levels of depression, anxiety, and stress are relatively high. High...

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07 Mar 2025

Research uncovers new information on the voice of the Philippine flat-headed frog found only in Palawan

This study describes the call of Barbourula busuangensis, a peculiar and elusive fully aquatic frog endemic to the Palawan archipelago...

Read More

06 Mar 2025

Lemongrass has the potential to control the growth of fungi from skin mycoses, foodborne illnesses and opportunistic infections

Lemongrass is an abundant medicinal plant that is used as an herbal remedy for fungal infections. Despite being widespread, to...

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04 Mar 2025

UP Diliman

A hybrid Internet of Things-based smart system performs better than a purely wireless sensor in monitoring indoor hydroponics farms

Internet of Things (IoT) is a one of the technologies that are being applied to various applications and scenarios. This...

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28 Feb 2025

UP Diliman

Transforming higher education requires a more diverse and inclusive landscape especially for women and minority groups in STEAM

This research dives into how higher education can be transformed through leadership focused on Equity, Diversity, and Inclusion (EDI). In...

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26 Feb 2025

UP Diliman

The proposed Input-Process-Output-Outcome/Result Model evaluates the success of the Philippine Olympic Committee Athletes’ Commission

The paper discusses the various institutions, laws, policies and programs of Olympic governance in the Philippines from the American era...

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25 Feb 2025

UP Diliman

Approximately 30% of older adults worldwide suffer from falls each year, making falls a critical public health issue

This study utilized baseline survey data from the Longitudinal Study of Ageing and Health in the Philippines (LSAHP) and the...

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18 Feb 2025

UP Diliman

Preventing frailty and depression may improve sleep health in those who are food insecure

Extensive research reveals the close relationship between food insecurity and the occurrence of sleep problems due to mental health. In...

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Research

The behavior of granular materials subjected to shaking or vibration remains a complex puzzling phenomenon. A reliable strategy in science to deal with such challenges is to use toy models as a starting point for a more complete and nuanced understanding. A toy model is an idealized version of the real thing reduced to its essential features. (The determination of what is essential is not simple and depends on one’s interest and purpose.)

The inelastic bouncing ball model (IBBM) was identified as a toy model for shaken granular materials. The IBBM treats the bulk of granular materials as a single inelastic ball on a harmonically vibrating container. The ball plate detaches from the container once its acceleration exceeds gravity and loses all its kinetic energy whenever it collides with the container.

The next step towards understanding is to analyze the discrepancies between the toy model and the real thing. More than a decade ago, it was observed that the time-of-flight of the shaken granular materials is less than what is predicted by IBBM. The researchers back then suspected that this discrepancy was due to the failure to consider the duration of the collision. However, this line of thought was not fully pursued until recently.

Recently, the team of researchers from the University of the Philippines consisting of Junius Andre F. Balista of UP Los Banos and Christian Jay P. Magsigay and Caesar Saloma of UP Diliman revisited the problem. Using numerical simulation (discrete element method) and analytical modeling, they analyzed the collision between the granular material and the container. They proposed a modification to IBBM by considering the collision time between the ball and its container as the range of uncertainty of the lift-off time of the ball.

There is more to be done but this is the first successful effort to include collision time in the formulation of IBBM, not to mention that not much has been accomplished on the issue in more than a decade. The modification of IBBM makes it applicable to other granular material phenomena driven by the material properties of the grains, such as the mixing and segregation of granular mixtures.

Authors: Junius Andre F. Balista (Institute of Mathematical Sciences and Physics, University of the Philippines Los Baños), Christian Jay P. Magsaysay (National Institute of Physics, University of the Philippines Diliman) and Caesar A. Saloma (National Institute of Physics, University of the Philippines Diliman)

Read the full paper: https://link.springer.com/article/10.1007/s10035-024-01403-9