De La Salle University - Manila

Research Abstracts

SY 2007-2008

College of Business and Economics

The Model Employers in the Philippines
51 RFG 3 04
Dr. Divina Edralin
Business Management Department

Human resource management performs an integral and strategic function in managing firms. It is a key management tool since human resources are considered essential in the continued existence and success of any business. It is therefore, not surprising that management continuously invests in the recruiting, training and motivating of its people to develop effective and efficient managers, supervisors, and rank-and-file employees.

This paper contains an in-depth look at those human resource management practices that make a company a model or a good company to work for. This two-year research effort, involving 20 companies listed in the Top 1,000 Corporations and 1,937 employees and management representatives showcases the distinguishing Human Resource Management practices related to recruitment, training and development, performance management, compensation, labor relations, health and safety, and leadership.

The Employee Opinion Survey results showed that the firms were rated very good in their HRM practices.

Based on the overall ranking of the judges across the seven HR practices, GMA Network got the highest ranking (x=2.72), followed by Ayala Land (x=5.00) and Yazaki-Torres (x=6.31). On the other hand, the lowest ranked companies are RFM (x=12.78); SKK Steel (x=13.16); and Fedders Koppel (x=13.66). Categorized by type of industry, Yazaki-Torres got the highest ranking in the manufacturing sector, followed by Unilever Philippines, and San Miguel Foods. In the non-manufacturing group, on the other hand, the highest rates companies are GMA Network; Ayala Land, and Toyota Makati.

The common emerging workplace patterns and best human resource management practices were clustered according to employment experience such as the creation of enabling structures and systems that intentionally enable individual employees and teams to translate the firms larger strategic goals into actual day to day work and achieve corporate goals; leadership such as focusing on the corporate vision-mission-goals and using self-empowering teams; and labor relations like engaging in productive social partnership of labor and management.

College of Computer Studies

Metaphors and the Construction of Knowledge
67 F U 3 06
Dr. Zelinna Cynthia Pablo
Information Technology Department

In this study I examine metaphors on web-based portals, in particular examining their implications on how knowledge is constructed. Using case methods and discourse analytic techniques, I conduct a comparative study of Web-based portals established under a World-Bank project known as the Development Gateway. Drawing from previous work that suggests that three metaphors (expert, market, and community) are significant across portals, I select an "expert" portal and a "community" portal to examine particular ways in which knowledge comes to be constructed. My findings suggests that the expert portal is linked with the view of knowledge as universal, whereas the community portal is linked the view of knowledge as socially constructed. This in turn has implications on which stakeholders have more voice or less voice in the knowledge production process. An expert portal appears to be characterized by tightly controlled processes of knowledge construction wherein participants are limited to a few key players, while a community portal appears to have participative, relatively unstructured processes of knowledge production.

 

Plagiarism Detector Generator
40 F U 2 06
Dr. Rachel Edita Roxas
Software Technology Department

This study involves the design and implementation of a plagiarism detector generator for OO student programs and performs the lexical and structural similarity measures of OO student programs using Java programs for testing. The system would accept as input the grammar of the programming language. The application would accept one folder per program group as input. Plagiarism styles to be detected by the system include but are not limited to (1) insertion, deletion and modification of comments, (2) changing names of variables, attributes and methods, (3) Changing the ordering of blocks of statements, (4) Changing the formatting of the source code, (5) Extraction of source code to a method, (6) copying the source code as it is.

Testing was done in two parts. The first part uses the RKR algorithm implementation v1.0. The second one uses the verson 2.0 that addresses the inaccuracy of the plagiarism technique EXTRACT. The first part of of the testing uses ten program specifications (labeled as 1, 2, to 10). For each program specification, we considered one original program, five individuals (labeled as A, B, C D and E) implemented one each non-plagiarized independently coded program based on the program specification based on the original program using the five plagiarism styles. The respective percent accuracies in positively identified plagiarized codes for BLOCKS, VARIABLES, COMMENTS, EXTRACT and FORMAT are 78, 100, 100, 36 and 100. From the results, we can infer that some plagiarism techniques can be successfully detected by the RKR-GST pattern matching algorithm such as VARIABLES, COMMENTS and FORMAT which had 100% accuracy. BLOCKS obtained a 78% accuracy, while EXTRACT obtained a mere 36% accuracy. The overall positively identified plagiarized copies obtained 83% accuracy.

From the results, the plagiarized programs that used the extraction method are not easily detected in the Plagiarism Detector 1.0. Version 2.0 was developed, and plagiarized programs that used the extraction method have been detected from 83 to 100% similarity measures with 100% detection. Unfortunately, it also obtained a 37.5% false positives.

 

College of Education

Comparing Models for Generating a System of Activation and Inhibition of Self-Regulated Learning
27 D U 2 07
Dr. Carlo Magno
Counseling and Educational Psychology Department

The study investigated the effect of activation and negative affect on self-regulation. The activation factors are self-determination, disengagement, initiative, and persistence while negative affect is composed of worry, anxiety, thought suppression, and fear of negative evaluation. Separate measures were used for each factor and administered to 1454 collegiate students. A time-wave design was used where the activation and negative affect factors were administered in the first wave and the self-regulation in the second. It was hypothesized in the study that the effect of negative affect on self-regulation can be moderated by levels of activation factors. Three models were tested using Structural Equations Modeling (SEM) to determine which structure of negative affect and activation best generates self-regulation. The results show that activation and negative affect each differently affect self-regulation, p<.001 (RMSEA=.054, 2=505.43, GFI=.96). Negative affect can increase self-regulation when mediated by activation, p<.001 (RMSEA=.056, 2=527.22, GFI=.96). The effect of negative affect on self-regulation is weak if individuals posses high activation levels, p<.001 (RMSEA=.05, 2=309.64, GFI=.97). The theoretical and educational implications of the findings are discussed.

 

Towards an Understanding of Spirituality and Perspectives on Teaching of Teachers from Selected Catholic Secondary School in Metro Manila
Dr. Roberto Borromeo
Educational Leadership and Management Department

This study is the second phase of the two-phased study on "Spirituality in the Educational Workplace". While the first phase focused on the spirituality and spiritual intelligence of administrators (Tanglaw, 2003, Vol. 9, No.2), the current study analyzed the teachers' spiritual intelligence, their definitions of spirituality and their views of teaching and students. The results showed that the respondents had a relatively high level of spiritual intelligence and spirituality which is manifested in their concept of teaching which focus on service, evangelization and integral formation, and their view of students which emphasizes respect for human dignity.

 

Exploring Assessment Reform Policy and Implementation in Philippine Public Secondary Education
34 F U 2 04
Dr. Sterling Plata
Department of English and Applied Linguistics

This paper analyses aspects of the assessment reform that started in 2003 in the Philippines by evaluating its policy and its implementation. Documents from the Department of Education pertaining to the reform were reviewed to trace the alignment of pedagogy, assessment, and proficiency in English. In addition, focus group discussions and interviews were also conducted to see how English teachers in rural and urban public secondary schools interpreted the changes mandated to them by the Department of Education. Data collection started in 2003 up to 2007. The study uncovered some factors that might have led to the limited implementation of the assessment reform by the participants in the study.

 

Language Amotivation and Approaches to Learning English among Filipino College Freshmen
24 F U 2 06
Dr. Rochelle Irene Lucas
Dr. Mildred Rojo-Laurilla
Department of English and Applied Linguistics

The present study explores Filipino college freshmen students' approaches to learning in relation to amotivation (possible lack of motivation in learning English as a second language) and related experiences in using English outside the language classroom. Adapting Biggs (2001) and Legault et al's (2006) to evaluate the learning approaches of the students in studying the target language, the researchers surveyed 224 students from different colleges in the university taking the first General Education English course (English one). The results of the study indicate that university freshmen students are neither predominant on either deep approach nor surface approaches to learning. They use both strategies to almost the same extent. In terms of dimensions of amotivation, the results indicated that freshmen students did not exhibit much of the indicators of amotivation implying that they still show interest and are motivated to learn English as a second language. The cohesiveness of their responses to questions on amotivation also indicated that they have more or less the same perceptions of the value of the task, task characteristics, and their beliefs about their abilities and efforts in learning English.

 

Towards Transformative Teaching and Learning in the College of Education: The Journey
44 F U 3 04
Dr. Auxencia Limjap
Science Education Department
Dr. Remedios Miciano
Dr. Leonisa Mojica
Department of English and Applied Linguistics

To help clarify and concretize the philosophy and practice of transformative teaching/learning for the College of Education faculty, modules on teaching philosophy and learning theories (Module 1), teaching strategy and assessment (Module 2), and classroom management (Module 3) were developed. Piloted on three different afternoons, the modules were each designed as a joint presentation between the researcher (as facilitator) and a resource person. All three modules merited a high evaluation from both the participants and the resource persons.

The main problem in piloting the modules was lack of time. Due to this problem, the assessment module was not carried out as it had been originally designed, and the workshop output (the reflection essays and the pedagogical plans of the participants) were sometimes short and sketchy. Nonetheless, as a whole, the design and piloting of the transformative teaching/learning modules was successful. Recommendations to further improve the content and delivery of the modules were given by the participants and the resource persons.

 

College of Engineering

Preliminary Evaluation of Biodiesel from Canarium ovatum (Pili) Pulp Oil and Psophocarpus tetragonolobus (Winged bean) Seed Oil
7 F U/C/S 1 05
Dr. Luis F. Razon
Chemical Engineering Department

Biodiesel or fatty acid methyl esters (FAME) derived from triglycerides of vegetable or animal origin has become very attractive because it is biodegradable, it comes from a renewable resource, it is frequently nontoxic and has been commonly accepted to be carbon-neutral. It is easy to manufacture and requires only small changes in the fuel distribution infrastructure as compared to the changes required if alternatives such as hydrogen were pursued. However, some concerns remain about the cost and availability of feedstocks. The paper presents preliminary studies conducted on biodiesel derived from two novel sources of oil: the fruit pulp of Canarium ovatum (pili) and the seed of Psophocarpus tetragonolobus (winged bean). Oils were extracted using hexane and converted to fatty acid methyl esters. To convert the oils to FAME, a combination of acid-catalyzed esterification and base-catalyzed transesterification was found to be necessary after the oils were found to have a free fatty acid content greater than 0.5%. The resulting FAME were found to comply with selected parts of the biodiesel standards (ASTM D6751-02, EN14214 and PNS2020:2003) except for the kinematic viscosity of the FAME from winged bean which was above the maximum limit for the Philippine standard, PNS2020:2003. The study has presented initial results, which indicate that acceptable FAME may be obtained from these two new potential sources of feedstocks. This gives more alternatives to those who want to explore commercial exploitation.

Commercialization of Acidic Geothermal Wells by pH Buffering
05 RP (URCO) 1 SY2002-2003
Dr. Yolanda Brondial
Chemical Engineering Department

The Philippines being part of the "Pacific Ring of Fire" has abundant geothermal energy. However, since a substantial number of drilled wells produced acidic geofluid with high enthalpy and high wellhead pressure, it becomes imperative to research and develop methods/techniques to be able to use these wells for power generation.

A potential pH buffering method for commercializing high-enthalpy acidic geothermal wells was explored in this study to raise the pH of the geofluids to greater than 3.5, a level considered by geothermal reservoir engineers to be non-corrosive to low-carbon steel. The pH buffering was modeled using statistical software with five design factors (pH geofluid, pH buffer, volume buffer, concentration buffer and temperature of solution), and one response factor (pH of resulting solution). The buffer used was ?-chloropropionic acid-Sodium ?-chloropropionate (BCPH-NaBCP). Experiments were conducted according to two different experimental designs with the second using the range of values found more effective from the first design. Experimental laboratory results showed that BCPH-NaBCP could raise the pH to > 3.5 for the first design and equal or greater than 4 for the second design and that the initial pH of geofluid, the pH, concentration and volume of BCPH-NaBCP solution significantly influenced the pH of the final solution. In both designs, the temperature of the solution did not show any significant effect on the buffered pH. It was also found out that for a closer range of conentration as in the second design, there was no significant change in the buffered pH. The best combination of factors in the first design was then used in a bench-scale set-up to investigate the possibility of applying pH buffering at high velocity. Results showed that BCPH-NaBCP was useful for fast buffering and could be used to commercialize acidic wells.

 

Integrating Affective Requirements in Car Design Methodologies
Ms. Rosemary Seva
Industrial Engineering Department

This study aims to validate a product design model using the concept of pre-purchase affect in a case study of car design in the Philippines. It is hypothesized that car attributes related to form can explain the experience of intense emotion in the car buying process and that this experience as well as good performance of sales agents can independently influence purchase intention. A field study was conducted in car dealerships of four car companies in the Philippines. A total of 133 samples were gathered consisting mostly of expert car buyers. Results of the study indicate that affective responses of consumers are triggered by both product form and function. However, more variables related to product form can explain the intensity of PPA such as shape and dimension. Intense experience of affect triggered a greater chance of purchasing the product. The performance of salesperson in the showroom cannot adequately explain the variation in data although the model is significant. However, helpfulness of the agents is a significant explanatory variable for purchase intention.

A Comparative Analysis Between the Seafood Industries of the Philippines and the Asia Pacific Region Countries
44 S U 3 06
Dr. Anna Bella Manalang
Industrial Engineering Department

The fisheries sector plays a major role in the Philippine economy as it continuously provides employment to about one million of its currently 80 million constituents and generates revenue, the foreign trade performance of the fishery industry in 2004 registering a net surplus of 433.1 million dollars. However, the Philippine fisheries are presently threatened due to poor management. This has caused the stagnation of the industry resulting to decreasing fish catch and habitat degradation. This is happening to the Philippines while fisheries in other countries flourish. This study documents the performance of the fisheries sector of the different countries found in the Asia-Pacific region. It identifies different factors, which play a role in the performance of fisheries of the different respective countries identified. The study starts with an over-all look at the industry in the region. It then delves into the industry of each country. It touches upon the economic impact and the recent trend of the industry for each country. The study then centers on the Philippine fisheries, touching upon issues that may have contributed to the decline of the industry.

 

Autonomous Mapping Robot Using Odometry and Sonar Sensors
32 F U/C 2 06
Ms. Phyllis Lim
Manufacturing Engineering and Management Department

Today, some robots use pre-specified maps to help them do their tasks like transporting or searching items. Minor changes in the environment may pose problems because it may impede the movement or function of the robot. This project aims to create a self-navigating, map-generating mobile robot using an array of ultrasonic sensor and odometry. The mobile robot successfully demonstrated the capability to build two-dimensional profile of the navigated environment. If accomplished this through a repetitive process of moving to a new position, sensing the environment, updating the map and planning subsequent motion. This demonstrates that an autonomous mapping mechanism can increase the versatility of a robot by allowing it to react to changes in the environment and adjusts actions accordingly.

Indoor Air Quality Investigation of Classrooms in Selected Grade Schools in Metro Manila
21 F U/S 1 05
Dr. Manuel Belino
Mechanical Engineering Department

This study investigated the indoor air quality of selected grade school classrooms in Metro-Manila. It considered three schools located in strategic areas; namely, northern, central, and southern part of the metropolis. Air sampling tests determined the concentration of chemical contaminants such as carbon dioxide, carbon monoxide, nitrogen oxide, benzene, and toluene. The concentration of total respirable dust, temperature and relative humidity of the indoor air were also determined.

The level of chemical contaminants and total respirable dust found in all the grade school classrooms of the three schools selected in the study were below the maximum threshold limit value. Although considerable amount of carbon dioxide was detected during the air sampling, its highest concentration level was still within the threshold limit value based on the Occupational Safety and Health Standard of the Department of Labor and Employment. The recorded temperature and relative humidity were generally within the design conditions for comfort cooling except those in fan-ventilated classrooms.

The common sicknesses and/or discomforts that the children reported they experienced in the classrooms such as colds, cough, headache, nausea and difficulty in breathing were poor air quality related respiratory sicknesses/discomforts. However, such could not be attributed to indoor air pollutants such as the chemicals and volatile organic compounds since their concentration levels were within the threshold limit value of the standard.

Thermodynamic Analysis of Integration Options to Improve the Net Energy Balance of Biofuel Production
(Paper: A Fuzzy Linear Programming Extension of the General Matrix-based Life Cycle Model)
12 F U/C 3 06
Dr. Alvin Culaba
Mechanical Engineering Department
Dr. Raymond Tan
Chemical Engineering Department

A fuzzy linear programming extension of the general life cycle model is described. The model is suitable for applications involving system design and optimization wherein fuzzy target levels for environmental flows or impacts are specified, and wherein multiple technological alternatives capable of providing equivalent products or services are present within the life cycle boundaries. Solving the model results in an optimal mix of technologies that embodies the best compromise of the fuzzy environmental targets specified. The model formulation is concise and consistent with the generalized matrix-based LCA model; its linearity also makes identification of the optimal solution straightforward. Applications of the model to two illustrative case studies are also given.

 

College of Liberal Arts

Explaining Angelo: The Philippines as a Developing State in the US-led Coalition of the Willing
26 F U 2 04
Mr. Edito Gan
International Studies Department

This study will explore the development of international security cooperation against terrorism since 9/11 and the part that developing states play in it. Using the Philippine government's attempts to negotiate and eventually come to terms with the terrorist Islamic Army (Khaled bin al-Waleed corps) for the release of Angelo De La Cruz in July 2004 despite US disapproval as case stusy, the proponent will employ a two-level model to ascertain how domestic pressure affects a developing state's commitment to international cooperation against terrorism in hosspots like Iraq.

The Politics of Ethnicity and Self-determination: The Making and Unmaking of the Moro Secessionist Movement
36 N 2 03
Dr. Rizal G. Buendia
Political Science Department

This paper is another effort to examine the issue of Muslim separatism. However, unlike other approaches the study analyzes secessionism from the perspective of ethno politics. It brings in the ethnic factor in the conflict between the state and Muslims' quest to create their own nation-state. It appraises the significance of the politics of ethnicity in strengthening and weakening of Muslims idea of Bangsamoro identity and how such identity serves a political purpose.

Using a hybrid framework which combines Paul Brass' and Abner Cohen's instrumentalist approach to ethnicity on the one hand and Michael Hechter's and Michael Banton's rational choice theory on the other hand, the paper argues that the complexity of the current separatist war is not simply due to the weakness of the state but also due to the weakness of the Bangsamoro identity and notion of nationhood. This frailty allows the state to co-opt leaders of the movement and sabotage their legitimate quest to self-governance and political autonomy.

The reinvention of the Moro struggle towards self-determination is likewise examined using the just-cause or remedial right theory of secession advocated by Allen Buchanan and Anthony Birch, among others. This part of the study argues that although Moro self-determination would not be a promising agenda due to the international community's effort to protect the state's territorial integrity, secessionism cannot be ruled out as long as the state fails to address the legitimate demands and grievances of Muslims to meaningful self-governance.

The study concludes that the threat of national disintegration will continue until an appropriate and responsive institutional framework for political governance which can accommodate Mindanao's social and ethnic diversity is determined. Hence, there is a need to lay emphasis on local good governance, the rule of law, improved civil-military relations, accountability of public officials for corruption, and human rights protection. To a large extent, these efforts will accelerate the early conclusion of conflict, hasten the process of peace building, and find a respectable and honorable final peace agreement between contenting forces. And more importantly, these would not only strengthen the Philippine nation-state but also considerably foster a cohesive national society.

Parents Living with HIV/AIDS
27 F U 1 05
Dr. Roberto Javier, Jr.
Psychology Department

This is an exploratory-descriptive research on the lives of mothers and fathers infected with the deadly virus, the Human Immunodeficiency Virus. The study employed the narrative interview method to generate stories of needs, concerns and experiences of parents living with HIV and the effects of chronic illness on their individual life as well as on their family affairs. The field researcher, a single person also positive with the virus used a set of guide questions to conduct interviews with 30 parents living with HIV. These parents were contacted through networking with local AIDS NGO's and their consent to disclose the diagnosis and to share their story was sought prior to the actual interview. Transcript of interviews were content-analyzed to form categories. Parents with HIV were in their early and middle adulthood. All the parents contracted the virus sexually while their children were infected through maternal-to-child transmission. Almost all of them acquired the virus abroad. Almost all the men infected their spouses. The deadly virus was detected upon the death of a partner in AIDS-related illness. Diagnosis of children was acquired as the mother was identified HIV-positive. Single parents with HIV retorted their difficulties in parenting alone as a consequence of the death of a spouse. HIV-positive parents were distressed by their own dying with the illness and were in a dilemma of disclosure. However challenged with the problems of daily living, these parents continue to be involved in the development of their children through their life course. Parenting their sons and daughters provides them with a sense of accomplishment as being mothers or being fathers. Yet, they were still silently in sorrow and grief while living with the socially stigmatized disease. Providing psychosocial care for afflicted children and individual psychotherapy for patients, parents and children with HIV will promote wellness in the family.

 

Preadoption Risk, Adoption Secrecy, and Family Functioning as Predictors of Adjustment of Filipino Adopted Children
39 RP-D U/C 2 05
Dr. Ma. Caridad Tarroja
Psychology Department

This study looks into the preadoption risk and postadoption factors (adoption secrecy and family functioning) that significantly predict the adjustment of 32 adopted children. Latent variable path analysis using partial least squares was employed to look into relationships among the latent variables and relationships between a latent variable and its indicators. Qualitative data and illustrative cases were likewise analyzed to look into variables that were deemed important factors in the adjustment of adopted children. The results consistently show that family functioning is the single important factor for Filipino adoptive families. Although no significant direct link exists between preadoption risk and adoption secrecy and adjustment of adopted children, adoption communication proves to be a significant predictor of family functioning.

The Catholic Social Teachings and the University
54 F U 3 06
Dr. Ferdinand Dagmang
Theology and Religious Education Department

The task of disseminating/teaching the Catholic Social tradition within the University cannot skirt around the person and location of the academician/professor and the hearers' context and concerns. The academician's expertise, exposure to various disciplines, and especially the culture of research would, however, introduce a certain problematic with regard to the particular process of handing on a tradition to students. This problem/tension between dissemination and interpretation reflects the classic hermeneutic problem. Using some principles of interpretation, this article clarifies the task of a creative dissemination as essential to the handing on of Tradition. Teaching the Catholic Social Teaching tradition becomes not only transmitting content but also an involved and embedded process of passing on a meaningful and valuable heritage. This concern to disseminate a significant Catholic Social Teachings tradition within the University may entail the development of the following: 1) attention to students' social condition; 2) a more critically-informed social commitment; 3) the cultivation of an inter-disciplinary expertise and; 4) the nurturing of a deeper social awareness. All of these would enhance the process and exercise of relevant dissemination.

Interreligious Dialogue Since Second Vatican Council: Retrospect and Prospect (In Response to the Call of FABC on Interreligious Dialogue)
29 S U/C 2 04
Dr. Ismael Maningas, Jr.
Theology and Religious Education Department

Synopsis
The last thirty years, have seen ample statements issued at FABC assemblies, seminars and two volumes of the collection of FABC documents from 1970-1991, from 1992-1996 and 1997-2001 published under the title "For All the Peoples of Asia" are calling for the Church to take seriously this agenda of dialogue. However, a serious and critical look at our churches here in Asia, would lead us to a conclusion that dialogue seems rather low in the priority list and there seems to be a gap between theory and practice as commented by Bishop Lawrence Thienchai Samanchi, D.D.

Bishop Lawrence Thienchai Samanchi noticed that part of the reasons for this gap and disparity is lack of formation and information on the new thrust of the Church in Asia. Many have no access to the post-Vatican II teachings about the Church's relation with other religions, in part because Church documents are sometimes too technical to be understood by the ordinary lay.

In this light, "The Resource Manual for Catholics in Asia Dialogue", edited by Franz-Josef Eilers, SVD, is an attempt to address the issue, however it only hopes to play a small role in the education and formation of persons for interreligious dialogue. For this reason, this book aims at giving a bigger role in the education and formation of persons for interreligious dialogue.

 

College of Science

Isolation, Structure Elucidation and Antimicrobial Assay of Secondary Metabolites from Six Philippine Medicinal Plants
19 S U/C/S 1 06
Dr. Consolacion Y. Ragasa
Chemistry Department

The air-dried leaves of Tectona philippinensis, an endemic and endangered Philippine medicinal tree, afforded four new chromomoric acid derivatives (1, 2, 3a and 3b). Their structures were elucidated by extensive 1D and 2D NMR spectroscopy. Antimicrobial testing was carried out on 1-3 against a panel of bacteria and fungi. The following known compounds were also obtained from the leaves of the plant: 5-hydroxy-3,7,4'-trimethoxyflavone (4), 5,4'-dihydroxy-3,7-dimethoxyflavone (5), squalene (6), a mixture of lupeol (7a) and β-amyrin (7b), chlorophyllide a (8), and hydrocarbons. Antimicrobial tests on 4 and 5 indicated low antifungal activity against the fungi, C. albicans and T. mentagrophytes. Compound 4 was also found to have low antibacterial activity against E. coli and P. aeruginosa.

SEE FIGURE 1

The dichloromethane extract of the corm of Musa errans, an endemic form of wild banana afforded 31-norcyclolaudenone (1), squalene, and a mixture of stigmasterol and sitosterol. The structure of 1 was elucidated by extensive 1D and 2D NMR spectroscopy. Antimicrobial tests on 1 indicated that it has low activity against C. albicans; E. coli, P. aeruginosa, and T. mentagrophytes; and inactive against B. subtilis, S. aureus, and A. niger.

SEE FIGURE 2

The dichloromethane extract of the air-dried flowers of Tagetes erecta afforded 2,2':5',2'-terthiophene (1) and 5,7,4'-trihydroxyflavanone (2). Compound 2 showed moderate activity against C. albicans, low activity against E. coli, P. aeruginosa, S. aureus, and T. mentagrophytes, and inactive against A. niger. Compound 2 was tested for cytotoxicity against a human lung non-small cell adenocarcinoma (A549) cell line and a normal Chinese hamster ovarian cell line (AA8). It was found inactive against A549 and AA8.

SEE FIGURE 3

The stem of Pouteria campechiana afforded 1 and a mixture of 2 and 3 in a 0.3:1 ratio by silica gel chromatography. Their structures were elucidated by extensive 1D and 2D NMR spectroscopy. Antimicrobial tests on 1 and a mixture of 2 and 3 indicated that they are slightly active against the bacteria, E. coli and P. areruginosa and the fungi, C. albicans and T. mentagrophytes. They are inactive against S. aureus, B. subtilis, and A. niger.

SEE FIGURE 4

The dichloromethane extract of the air-dried flowers of Michelia champaca afforded 11,13-dehydrolanuginolide (1) by silica gel chromatography. The structure of 1 was elucidated by extensive 1D and 2D NMR spectroscopy. Antimicrobial tests on 1 indicated that it is moderately active against the fungus, Candida albicans. It has low activity against the bacteria, P. aeruginosa and E. coli and the fungus, T. mentagrophytes. It is inactive against S. aureus, B. subtilis, and A. niger.

SEE FIGURE 5

Air-dried leaves of Citrus microcarpa Bunge afforded 3',4',5,6,7,8-hexamethoxyflavone (1) and squalene. The structure of 1 was elucidated by extensive 1D and 2D NMR spectroscopy. Antimicrobial tests on 1 indicated that it has moderate activity against the fungus, C. albicans and low activity against the bacteria, P. aeruginosa and B. subtilis and fungi, T. mentagrophytes, and A. niger.

SEE FIGURE 6

GraphTEX
42 UERF 3 03
Dr. Severino Gervacio
Mathematics Department

(42 UERF 3 03)

Dr. Severino Gervacio
Mathematics Department

Preface

I first used plain T_EXsometime in 1992. I needed to draw graphs (a collection of vertices and edges) and I had to look for drawing packages to create my drawings. There was no single package that will serve my purpose and I had to write additional macros on top of those that are available. This challenged me to create macros to draw graphs. The first version of G^raphT_EX (which contains about 55 macros) appeared in 1994. This version of G^raphT_EXcontains about 168 macros for drawing graphs plus a lot more. Macros for drawing special graphs such as paths, cycles, fans, wheels, complete graphs, complete bipartite graphs, and generalized Petersen graphs are included in G^raphT_EX Drawing Bézier curves with quadratic or cubic parametric equations are included. These are applied to make approximate drawings of circles, ellipses, hyperbolas, and sine and cosine curves. The approximation is shown to have a high degree of accuracy by showing that the maximum error in the drawing is very small and negligible. Parabolas are drawn correctly using second degree Bézier curves. G^raphT_EX is also capable of performing translation, reflection and rotation. Three-dimensional drawings and graphs can be created using G^raphT_EX. Miscellaneous macros about summation, multiplication, day, date, time, etc. are also included.

I hope that G^raphT_EXcould provide most if not all the things that one needs in making drawings in a T_EXor L^AT_EXdocument. What G^raphT_EXlacks could perhaps be added without much difficulty by building other macros from its existing macros.

This project which consisted of expanding and enhancing G^raphT_EX including the writing of this book was done during the period September 2004 to August 2005 under the Research Faculty Program of De La Salle University-Manila.

 

Quantum Percolation of Infinitely-Sized Disordered Clusters in Two Dimensions
58 N 3 05
Dr. Eduardo C. Cuansing Jr.
Physics Department

(58 N 3 05)

Dr. Eduardo C. Cuansing Jr.
Physics Department

We study the hopping transport of a quantum particle through finite, randomly diluted percolation clusters in two dimensions. We investigate how the transmission coefficient T behaves as a function of the energy E of the particle, the occupation concentration p of the disordered cluster, the size of the underlying lattice, and the type of the connection chosen between the cluster and the input and output leads. We investigate both the point-to-point contacts and the busbar type of connection. For highly diluted clusters we find the behavior of the transmission to be independent of the type of connection. As the amount of dilution is decreased we find sharp variations in transmission. These variations are the remnants of the resonances at the ordered, zero-dilution, limit.

For particles with energies within 0.25 ≤ E ≤ 1.75 (relative to the hopping integral) and with underlying square lattices of size 20 x 20, the configurations begin transmitting near P_α = 0.60 with T against p curves following a common pattern as the amount of dilution is decreased.

Near P_β = 0.90 this pattern is broken and the transmission begins to vary with the energy. In the asymptotic limit of very large clusters we find the systems to be totally reflecting in almost all cases. A few clear exceptions we find are when the amount of dilution is very low, when the particle has energy close to a resonance value at the ordered limit, and when the particle has energy at the middle of the band. These three cases, however, may not exhaust all possible exceptions.