Heteroatom Effects in Polycyclic Aromatic Hydrocarbons

There are several peaks in the infrared (IR) spectrum of planetary nebulae (PNe) like NGC 7027 whose origins are unknown. This has been a long-standing puzzle in the study of PNe. This project explores heteroatom substitution in polycyclic aromatic hydrocarbons (PAHs) as a possible origin for these unidentified infrared emission (UIE) peaks. The heteroatom elements explored in this study are nitrogen, oxygen, phosphorus, silicon, and sulfur. Previous work has demonstrated that 3- and 4- ring PAHs emit a spectrum close to current spectrum data for UIE and a previous group tested nitrogen substitution in similar structures with varied results. I used the Gaussian 09 program to model these PAHs substituting carbon with these heteroatom elements and a Python program adapted from GaussSum to analyze the resulting spectra of these molecules. I, first, analyzed the stability of the substituted PAHs by calculating their formation energy. Phosphorus had the lowest formation energy of all the heteroatoms with an energy of -0.1968 eV for the most stable substitution. Overall, I found that the heteroatom substituted PAHs were fairly stable and could possibly be found within the circumstellar environment of PNe. Calculated IR spectra will be compared with IR spectra from planetary nebulae

Collecting Data on Brightness Variations in the Central Stars of Planetary Nebulae Using Sky Surveys

Research on planetary nebulae is shifting from the source of their fascinating shapes to details on how those shapes are created. The overall goal of this project is to measure the fraction of planetary nebulae that have binary central stars. In order to do this, a large amount of data is required. So we took the list of planetary nebula targets identified in Gaia data and a list of nearby, known planetary nebulae and ran them through available online databases. These databases provide data on the brightness of these stars over time. For over 2,000 objects from the Gaia list, the Catalina Sky Survey (CSS) had data on 35 of them. 16 objects exhibited possible variability. Using the Palomar Transient Facility (PTF) and the Zwicky Transient Facility (ZTF) databases, only 4 of those appeared in the PTF and 6 in the ZTF. We narrowed the initial Gaia list to only objects with magnitudes from V = 14-16 and ran them through the All-Sky Automated Survey for Supernovae (ASAS-SN). Out of 123 objects, we found data for 96. We ran the entire list of nearby objects through ASAS-SN and found data for 113 objects of 167. We ran period searches on the data found from ASAS-SN using Period04. 14 of the objects from Gaia and 28 of the objects from the nearby objects list looked potentially variable. We present here results on some of the detected variables, preliminary statistics and a discussion of the search process

Apocalipsis: La obra presente y futura de Dios (estudio del libro de Apocalipsis)

Este último libro de la Biblia, Apocalipsis, es una revelación de Dios para el beneficio nuestro y que es vigente para cada generación. El escrito del desterrado Apóstol Juan, trata del juicio final y del nuevo mundo del futuro, más allá de la historia actual. Aquí descansa nuestra esperanza y la de cada generación. Esta es la esperanza que le da fuerzas en medio de todas las tribulaciones y sufrimientos. ¿Por qué? Conocemos a Jesucristo, quien murió por nuestros pecados al rindió Su vida por la nuestra. Su resurrección es entonces también nuestra resurrección. Él es nuestro Salvador, nuestra razón de ser, nuestro motivo de paz, certeza y seguridad, nuestra perfecta esperanza, nuestro descanso eterno, nuestro paraíso, nuestra resurrección, nuestro gozo para siempre, nuestra vida eterna. Incluye: Manual de estudio

A study of the metal binding capacity of saccharinic acids formed during the alkali catalysed decomposition of cellulosic materials: nickel complexation by glucoisosaccharinic acids and xyloisosaccharinic acids

The stoichiometry of the metal complexes formed between nickel and the ligand β-glucoisosaccharinic acid (β-GISA) and a racemic mixture of enantiomers of xyloisosaccharinic acid (XISA) has been determined at both neutral and alkaline pHs. Bjerrum plots, Job's plots and conductance measurements indicated that for each of the systems one to one Ni(ligand) complexes were formed at near neutral pHs (13) sparingly soluble Ni2(ligand)(OH)4 complexes were formed. The stability constants for the Ni(β-GISA), Ni(α-GISA) and Ni(XISA) complexes formed at neutral pH were determined under identical conditions using polarographic studies. The measured stability constants for Ni(β-GISA) (log10 β = 1.94 ± 0.15) and for Ni(α-GISA)(log10 β = 2.07 ± 0.13) are very similar; the value measured for the Ni(XISA) complex (log10 β = 0.83) was an order of magnitude smaller. The stability constants for the Ni2(Ligand)(OH)4 complexes formed at highly alkaline pHs were determined using the Schubert method. The measured stability constant for Ni2(β-GISA)(OH)4 (log10 β = 30.6 ± 0.5) was an order of magnitude bigger than the value for Ni2(α-GISA)(OH)4 (log10 β = 29.0 ± 0.5) measured under identical conditions. Attempts to measure the stability constant for Ni2(XISA)(OH)4 were unsuccessful; Ni2(XISA)(OH)4 complexes were not present in significant amounts at high pH to allow the log10β value to be determined by the Schubert method

Jeremías: El mensaje de Dios, ayer y hoy (del profeta Jeremías)

Un curso avanzado sobre el profeta Jeremías, el profeta de la esperanza, en el contexto del Antiguo Testamento. Este curso utiliza el método de investigación inductiva bíblica. Tiene el propósito de enseñar a los estudiantes a interpretar un libro profético del Antiguo Testamento y aplicar sus enseñanzas a nuestra realidad. Incluye: Manual del alumno

Bautismo de niños

Bautismo de niño