63 research outputs found

    Synthesis and characterization of a new octafunctional epoxy resin (Octaglicydil tetra p-aminophenol of bisphenol A (Bis para phosphoric ester)). Viscosimetric study.

    Get PDF
    In this work, we synthesized a new octafunctional epoxy resin: Octaglicydil tetra p-aminophenol of bisphenol A (Bis para phosphoric ester) (OGTPAPBABPPE). This resin was synthesized in three steps. The first step is intended to condense the phosphorus trichloride and the bisphenol A; the second step was to introduce an aromatic spacer arm between the major epoxide functions and the nucleus of bisphenol A, by reacting p-aminophenol in the precursor dichloride phosphorus bisphenol A; in the third step, we functionalized the latter by the epichlorohydrin.The obtained resin was very viscous and brownish. The latter was characterized by infrared Fourier transform spectroscopy (FTIR), and its chemical structure was also confirmed by proton nuclear magnetic resonance of 1H, 13C atoms and phosphorus 31P (1H NMR, 13C NMR, 31P NMR). The study of viscosi-metric properties was carried out by the viscometer of Ubbelohd type

    Philippines

    Get PDF
    This report discusses the extent of compliance of a higher education institution in Isabela, Philippines with the ISO 9001:2015 Quality Management System. An internal audit for clauses 4 to 9.1 of the QMS was conducted to determine the extent of QMS implementation and to identify areas of conformities, opportunities for improvement, and nonconformities. Out of the 215 findings, 177 are conformities (Cs); 25 are nonconformities (NCs); while 13 are opportunities for improvement (OFIs). The strengths of the organization include its understanding of its context, leadership of the top management, existence of planned actions to address risks and availability of almost all significant documents that support compliance and/or sustain the quality operations. Areas that need to be improved and complied include inadequate manpower for quality activities, unmet targets, and lack of control for externally provided products and services. Actions to address these findings are provided. Thus, the organization is highly recommended to carry out the corrective actions as soon as possible for continual improvement

    College students’ problems and their link to academic performance: Basis for needs-driven student programs

    Get PDF
    Students are facing various challenges in life that may have adverse effects to their academic performance yet someschool programs are not student needs-driven. This descriptive research study discusses the problems experienced by the 350 students of a higher education institution in the Philippines with the hope to craft activities that are responsive to their needs and academic achievement. The data were collected through questionnaire and registration methods. Descriptive analysis shows that around 9 percent to 23 percent of the students experience problems in academic, social, family, emotional, personal, financialand spiritual aspects whose degree ranges from moderate extent to very great extent. The problems reflect teachers’ lapses in classroom management and pedagogy, and lack of activities that support students’ holistic development and effective learning habits. Linear regression analysis confirms that their problems explain significantly a variance that ranges from 19 percent to 36 percent in their academic performance. Hence, this research offers implications that can help address the adversaries of high academic achievement

    Comparative study of inhibitory efficacy of methionine and its derivatives in acidic medium by mild steel

    Get PDF
    Corrosion inhibition effect of L-Methionine (MT1), L-Methionine sulfoxide (MT2) and L-Methionine sulfone (MT3) on mild steel corrosion in 1M HCl solution was studied by using weight loss, electrochemical polarization and electrochemical impedance spectroscopy (EIS) techniques. The experimental results showed that the inhibitory efficiency of the three aminoacids improves with the increase of concentration to reach the maximum value of 95.20% for MT1, 94.14% for MT2 and 88.92% for MT3 for a concentration of 10-3M, which translates that the surface covered by the inhibitor increases with the concentration. The effect of temperature on the corrosion rate was investigated and some thermodynamic parameters were calculated. Polarization studies show that three studied inhibitors suggested that three inhibitors control the anodic as well as cathodic reactions and act as mixed type in nature. The results show that MT1, MT2 and MT3 are good inhibitors, and the adsorption of each inhibitor on mild steel surface obeys Flory-Huggins and Langmuir, with a better fit of the Langmuir isotherm through mixed adsorption (physisorption as well as chemisorption) process. In addition, the quantum approach based on density functional theory (DFT), monte Carlo (MC) and molecular dynamics (MD) simulations was confirmed the reactivity of the studied compound towards the corrosion process

    The Role of Social Interactions in Academic Satisfaction Among D/Deaf and Hard-of-Hearing (HOH) Students

    Get PDF
    This descriptive correlational study aimed to describe the demographics, level of social interaction, academic satisfaction, and the relationship between social interaction and satisfaction among d/Deaf and hard-of-hearing (HOH) students. The study purposively sampled 64 respondents, with 34 females (53.13%) and 30 males (46.88%), ranging from 18 to above 24 years old. Most of the respondents\u27 mothers (46.88%) and fathers (39.06%) attained a college level of education. More than half (58.26%) had 3-5 siblings. The majority (85.94%) were d/Deaf. Results showed that respondents had high levels of social interaction with their family (M=3.85), teachers (M=3.75), hearing students (M=3.75), and peers (M=3.78), with an overall grand mean of 3.78, indicating high social interaction. They also expressed satisfaction in terms of teaching (M=3.74), assessment (M=3.63), and generic skills and learning experiences (M=3.84), with an overall grand mean of 3.74, showing satisfaction. A Pearson’s r (correlational coefficient) statistical test revealed a strong positive correlation (r=0.847) between social interaction and satisfaction, and the relationship was found to be significant (p=0.000). This implies that social interactions were important in influencing the academic satisfaction of d/Deaf and hard-of-hearing students. The findings provide insights that can aid in developing support programs to enhance d/Deaf and hard-of-hearing students’ educational experiences. Instructional support can be provided to facilitate peer interactions further and improve learning experiences through additional academic and social resources. DOI: https://doi.org/10.52783/jchr.v14.i3.453

    Rheological and Electrical Study of a Composite Material Based on an Epoxy Polymer Containing Cyclotriphosphazene

    No full text
    In this work, we have studied, formulated, prepared, and characterized the rheological and electrical behavior of a composite material based on an epoxy resin Diglycidyl Ether of Bisphenol A (DGEBA) reinforced with hexaglycidyl cyclotriphosphazene (HGCP). The epoxy system was cured with 4,4’-methylene dianiline (MDA). DGEBA-HGCP-MDA epoxy composite materials with reinforced HGCP which varied from 5% to 10% by weight were prepared by mixing in the molten state. The morphology was evaluated by SEM. The rheological behavior was studied using small deformation rheology. The electrical characterization was carried out with a frequency variation range from 1 Hz to 100 KHz at room temperature. These measurements revealed that the rheological and electrical behaviors strongly depend on the quantity of HGCP in the DGEBA matrix. The linear viscoelastic properties study reveals that the modulus of elasticity G’ is dependent on the amount of HGCP present in the epoxy resin DGEBA. The capacitance-frequency measurements suggest a distribution of localized states in the band gap of the blends
    corecore