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Philippine Journal of Science - Vol 145 No. 3

EDITORIAL

Measuring the Performance of our Higher Education Institutions – Part I
Caesar A. Saloma

National Institute of Physics, College of Science
University of the Philippines Diliman, Quezon City, Philippines

Protein Profile of Three Developing Stage Chorion (eggshell) of Oxya hyla hyla (Orthoptera: Acrididae)
Arpita Shyam J. Roy and Durgadas Ghosh

In vitro Controlled Drug Release of Anti Cancer Drugs Deguelin and Cisplatin by Lauric Acid Derived Polyanhydride as Carrier
John Marty Mateo and Florentino C. Sumera

Assessing the Utilization of Falcata (Falcataria moluccana (miq.) Barneby & J.W. Grimes) for Lumber Production
Marina A. Alipon, Pablito L. Alcachupas, Elvina O. Bondad,
and Emelyn C. Cortiguerra

Suitability Assessment of Bantog Soil Series for Potential Enhancement of Rice-based Cropping Systems
Sandro D. Cañete, Wilfredo B. Collado, Rodrigo B. Badayos, Pearl B. Sanchez, and Pompe C. Sta. Cruz

Properties and Nutrient Status of Degraded Soils in Luzon, Philippines
Michelle Ann M. Calubaquib, Ian A. Navarrete, and Pearl B. Sanchez

Xerophytic Characteristics of Tectona philippinensis
Jonathan O. Hernandez, Pastor L. Malabrigo Jr., Marilyn O. Quimado, Lerma SJ. Maldia, and Edwino S. Fernando

Monte Carlo N-Particle Transport Code Simulation of Keksell Gamma Knife Using Disk Sources for Polystyrene, PMMA, Plastic Water and Head Phantom
Ma. Vanessa Francheska P. Perianes, Doreen Alexis F. Villanueva, and Jade R. Dungao

Total Phenolic and Total Flavonoid Contents of Selected Fruits in the Philippines
Mariam C. Recuenco, Marivic S. Lacsamana, Wilma A. Hurtada, and Veronica C. Sabularse

Possible Effects of El Niño on Some Philippine Marine Fisheries Resources
Amor M. Damatac II and Mudjekeewis D. Santos

Stress-based Kiln Drying of Gmelina arborea Roxb. Lumber
Wency H. Carmelo, Ramon A. Razal, Chrysline Margus N. Piñol, and James Fuller

Stress-Based Kiln Drying of Gmelina arborea Roxb. Lumber

Wency H. Carmelo1, Ramon A. Razal2*,
Chrysline Margus N. Piñol3, and James Fuller4

1Forest Products Research and Development Institute,
College, Laguna 4031 Philippines
2Department of Forest Products and Paper Science, University of the Philippines Los Baños
 College of Forestry and Natural Resources, College, Laguna, Philippines
3Institute of Mathematical Sciences and Physics,
University of the Philippines Los Baños College of Arts and Sciences,
College, Laguna, 4031 Philippines
4Fuller Drying Labs, Orange, Virginia 22960 USA

*Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

ABSTRACT
The study evaluated the kiln drying of 25-mm thick Gmelina arborea Roxb. lumber using conditions based on changing shrinkage rates following the procedure developed by Fuller under US Patent No. 5,873,182 dated 23 February 1999. For comparison, a separate kiln drying run was done following conventional, moisture content (MC)-based drying schedule. To monitor shrinkage, a linear variable differential transducer was mounted across a sample board that was coupled to a data acquisition system. Real-time shrinkage data was processed and the graph of dynamic shrinkage versus time provided information on peak stress, stress reversal and reduction of shrinkage rates. These transitions were taken as signals to advance kiln drying conditions to the next step prescribed in the MC-based drying schedule, which allowed prompt changes in kiln settings. The early transition in internal kiln drying conditions resulted to reduction in kiln drying time by 30 to 36%. The quality of the dried lumber was evident in the more uniform final moisture content distribution of the dried boards, less steep moisture gradient, and the absence of residual stresses in the boards dried in a kiln where changing shrinkage rates were used as basis for operation and control.

INTRODUCTION
Drying is one of the most important steps in the processing of wood.  The quality of finished products depends to a large extent on the moisture present in the wood at the time of manufacture.  For fast wood drying with minimal drying degrade, proper kiln settings as well as appropriate kiln drying schedules (KDS) must be followed. . . . . read more

 

 

Total Phenolic and Total Flavonoid Contents
of Selected Fruits in the Philippines

Mariam C. Recuenco1*, Marivic S. Lacsamana1,
Wilma A. Hurtada2, and Veronica C. Sabularse1

1Institute of Chemistry, College of Arts and Sciences,
University of the Philippines Los Baños, College, Laguna 4031 Philippines
2Institute of Human Nutrition and Food, College of Human Ecology,
University of the Philippines Los Baños, College, Laguna 4031 Philippines

*Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

 

ABSTRACT
In this paper, we surveyed the total phenolic and total flavonoid contents of 30 fruits in the Philippines.  Jamaica cherry (aratiles, Muntingia calabura), velvet apple (mabolo, Diospyros blancoi), tamarind (sampalok, Tamarindus indica) and lolly fruit (santol, Sandoricum koetjape) had the highest phenolic contents with >350 mg gallic acid equivalents (GAE)/100 g fresh matter (FM). Tamarind, velvet apple, lolly fruit and sugar apple (atis, Annona squamosa) had the highest flavonoid contents with >200 mg catechin equivalents (CE)/100g FM.  A moderate positive correlation was confirmed between the phenolic and flavonoid contents (r=0.745, p<0.0001). The abilities of the fruits to act as antioxidants were evaluated by the β-carotene bleaching assay. The % inhibitions of β-carotene bleaching varied largely and correlated weakly to the total phenolics and total flavonoids. This could indicate the partial contribution of phenolic and flavonoid contents to the antioxidant properties of the fruit samples. This study showed that fruits available in the Philippines are good sources of phenolics and flavonoids.

INTRODUCTION
Many studies suggest that consumption of fruits and vegetables reduces the risks of chronic diseases such as cardiovascular diseases and certain cancers (Arts and Hollmann 2005).  Oxidative stress due to increased levels of free radicals in the body is considered a factor in the development of these diseases. Phytochemicals have been reported to exhibit antioxidant activities by delaying or inhibiting the reactions of free radicals (Seifried et al. 2007).  The polyphenols are a group of phytochemicals that are ubiquitous components of fruits and vegetables.  Polyphenols include compounds such as flavonoids, phenolic acids, stilbenes, coumarins and tannins. . . . . read more

 

Possible Effects of El Niño on Some
Philippine Marine Fisheries Resources

Amor M. Damatac II and Mudjekeewis D. Santos*

1National Fisheries Research and Development Institute,
101 Mother Ignacia Street, Quezon City, Metro Manila, Philipines

*Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

 

ABSTRACT
El Niño is the warm phase of extreme climatic phenomenon observed in the equatorial Pacific. Over the past decades, frequent El Niño events have been observed and pose a great threat to biodiversity. This paper reviews the possible effects of El Niño on some marine fisheries resources based on past events. Reporting mostly the effects from 1982-1983 and 1997-1998 events, El Niño affected factors involved in ocean- atmospheric interactions such as sea surface temperature, salinity, nutrient availability, precipitation rate, and ocean currents, precipitation rate, and tropical typhoons in the equatorial Pacific. As a result, changes in these factors influenced marine organisms leading to increased phytoplankton biomass and widespread coral bleaching, and possibly resulting to fish kills, occurrence of seaweed diseases and threats to marine mammals. It affected pelagic fish species leading to migration or change in catch production. The data in this paper raise concerns on the predicted impact of El Niño on food security. Considering our susceptibility, key researchable areas need to happen to support management strategies that will mitigate possible effects of El Niño in the country.

INTRODUCTION
The Philippines has been assessed as one of the most vulnerable countries to the impacts of extreme weather brought by climate change (Harmeling, 2010; Santos et al., 2011).  The direct effects of climate change can occur through alteration in the behavior, morphology, and physiology of individual organisms, leading to a cumulative change resulting in ecosystem regime shifts (Food and Agriculture Organization, 2000; Brierly & Kingsford, 2009;Portner & Peck, 2010;  Doney, et al., 2012).Climate change is projected to impact the marine sector and this scenario poses great pressure to the livelihood and food security among Filipinos especially those who live in coastal areas where fishing is the primary source of livelihood. . . . . . read more

 

Monte Carlo N-Particle Transport Code Simulation
of Leksell Gamma Knife Using Disk Sources of
Polystyrene, PMMA, Plastic Water and Head Phantom

Ma. Vanessa Francheska P. Perianes, Dorren Alexis F. Villanueva,
and Jade R. Dungao

Physics Department, De La Salle University
Taft Avenue, Manila, Philippines

*Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

 

ABSTRACT
Stereotactic Radiosurgery (SRS) has become a standard modality for the treatment of benign and metastatic brain lesions that were deemed medically unsuitable for surgery. The Leksell Gamma Knife (LGK), a type of SRS that was used in this study, has 201 Cobalt-60 sources distributed in a hemisphere whose radiation intersects at the isocenter. The relative dose at the isocenter was verified using Monte Carlo N-Particle Simulation (MCNP). This study uses disk sources, an alternative for the full geometry collimator system of the LGK, to simulate a 160-mm water phantom made of different materials: polystyrene, plastic water, and PMMA (Polymethyl methacrylate). In addition, the simulation of a head phantom was also included in this study. Relative dose distributions were calculated and were compared to the relative dose distributions from the cited literatures. As a result, no significant differences have been found. In conclusion, the use of disk sources provides a simpler method of simulating the LGK instead of using the full geometry collimator system in the MCNP Visual Editor.

INTRODUCTION
Stereotactic Radiosurgery (SRS) is one of the treatment modalities used to treat benign and metastatic brain lesions. It is a specialized technique where a uniform dose, with highly conformal radiation, is delivered to the target.
The type of SRS that was used in this study was the Leksell Gamma Knife (LGK). LGK was developed by Swedish neurosurgeon Lars Leksell and Physicist Borje Larson. The LGK, manufactured by Elekta Instruments Inc., uses 201 Co-60 sources distributed on a hemisphere. The diameter of the beams of the ionizing radiation was defined by the collimator system and the shape of the target can be varied by changing the size of the collimator helmets:  4 mm, 8 mm, 14 mm and 18 mm. . . . . . read more

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