Biodegradation of rocket propellant waste, ammonium perchlorate

The short term effects of ammonium perchlorate on selected organisms were studied. A long term experiment was also designed to assess the changes incurred by ammonium perchlorate on the nitrogen and chloride contents of soil within a period of 3 years. In addition, an attempt was made to produce methane gas from anaerobic fermentation of the aquatic weed, Alternanthera philoxeroides

Dark-matter halo mergers as a fertile environment for low-mass Population III star formation

While Population III stars are typically thought to be massive, pathways towards lower-mass Pop III stars may exist when the cooling of the gas is particularly enhanced. A possible route is enhanced HD cooling during the merging of dark-matter halos. The mergers can lead to a high ionization degree catalysing the formation of HD molecules and may cool the gas down to the cosmic microwave background (CMB) temperature. In this paper, we investigate the merging of mini-halos with masses of a few 10$^5$ M$_\odot$ and explore the feasibility of this scenario. We have performed three-dimensional cosmological hydrodynamics calculations with the ENZO code, solving the thermal and chemical evolution of the gas by employing the astrochemistry package KROME. Our results show that the HD abundance is increased by two orders of magnitude compared to the no-merging case and the halo cools down to $\sim$60 K triggering fragmentation. Based on Jeans estimates the expected stellar masses are about 10 M$_\odot$. Our findings show that the merging scenario is a potential pathway for the formation of low-mass stars.Comment: Submitted to MNRA

Formation of carbon-enhanced metal-poor stars in the presence of far ultraviolet radiation

Recent discoveries of carbon-enhanced metal-poor stars like SMSS J031300.36-670839.3 provide increasing observational insights into the formation conditions of the first second-generation stars in the Universe, reflecting the chemical conditions after the first supernova explosion. Here, we present the first cosmological simulations with a detailed chemical network including primordial species as well as C, C$^+$, O, O$^+$, Si, Si$^+$, and Si$^{2+}$ following the formation of carbon-enhanced metal poor stars. The presence of background UV flux delays the collapse from $z=21$ to $z=15$ and cool the gas down to the CMB temperature for a metallicity of Z/Z$_\odot$=10$^{-3}$. This can potentially lead to the formation of lower mass stars. Overall, we find that the metals have a stronger effect on the collapse than the radiation, yielding a comparable thermal structure for large variations in the radiative background. We further find that radiative backgrounds are not able to delay the collapse for Z/Z$_\odot$=10$^{-2}$ or a carbon abundance as in SMSS J031300.36-670839.3.Comment: submitted to ApJ

Sistem dan Prosedur Penjualan Kredit Sepeda Motor pada Pt.smart Multi Finance Kecamatan Melak Kabupaten Kutai Barat

The objective is to determine whether the application of accounting system and procedures for credit sales at PT.Smart Multi finance in Melak are in accordance with the internal control system and procedures on credit sales in theory Mulyadi.Data were collected through a questionnaire to provide question to the responden regarding internal control for the implementation of system and procedures for credit sales in PT.Smart Multi Finance.The data obtained were analyzed using methods Champion is by counting the number of “yes”.The final score is used to conclude whether the systems and procedures are in accordance with the credit sales company's internal control theory mulyadi.The result showed that credit sales accounting is appropriate according to the internal control system and procedures on credit sales (Score 86,67%)