1,869 research outputs found

    Does a change in debt structure matter in earnings management? the application of nonlinear panel threshold test

    Get PDF
    In this study, we apply Hansen¡¦s (1999) nonlinear panel threshold test, the most powerful test of its kind, to investigate the relationship between debt ratio and earnings management of 474 selected Taiwan-listed companies during the September 2002 - June 2005 period. Rather than a fixed positive relation that is determined from the OLS, our empirical results strongly suggest that when a firm¡¦s debt ratio exceeds 46.79% and 62.17%, its debt structure changes, which in turn leads to changes in earnings management. With an increase in debt ratio, managers tend to manage earnings to a greater extent and at a higher speed. In other words, the threshold effect of debt on the relationship between debt ratio and earnings management generates an increasingly positive impact. These empirical results provide concerned investors and authorities with an enhanced understanding of earnings management, as manipulated by managers confronted with different debt structures.

    Zelena sinteza i primjena zeolita ZSM-5

    Get PDF
    A ZSM-5 molecular sieve composite with a wide pore prepared by the solid phase in-situ synthesis method and fluid catalytic cracking, and an FCC catalyst additive prepared by the same ZSM-5 molecular sieve for increasing the amount of light olefin yield were investigated. The samples were characterized by XRD, N2 adsorption/desorption, SEM, and NH3-TPD, respectively. The results showed that the structure of the ZSM-5 molecular sieve composite prepared by solid phase in-situ synthesis method was pure MFI-type zeolite material. The crystallinity of ZSM-5 molecular sieve was 59.8 wt%. The synthesized ZSM-5 molecular sieve had more acid content and a wide-pore structure. The average pore size was 5.9 nm, and BET specific surface area and micropore specific surface area of sample were 213 m2 g–1 and 124 m2 g–1, respectively. The evaluated results indicated that the FCC catalyst additive had good selectivity for LPG, propylene, and butene, increasing propylene and butene yields by 2.28 wt% and 2.15 wt%, respectively, as well as had better heavy oil cracking capability and coke selectivity. This work is licensed under a Creative Commons Attribution 4.0 International License.Istražen je kompozit molekularnog sita ZSM-5 sa širokim porama pripremljen sintezom na krutoj fazi in-situ i katalitičkim krekiranjem u vrtložnom sloju (FCC) te aditiv katalizatora FCC pripremljen istim molekularnim sitom ZSM-5 u svrhu povećanja količine prinosa lakog olefina. Uzorci su karakterizirani rendgenskom difrakcijom na prahu (XRD), adsorpcijom/desorpcijom N2, skenirajućim elektronskim mikroskopom (SEM) te temperaturno programiranom desorpcijom amonijaka (NH3-TPD). Rezultati su pokazali da je struktura smjese molekularnog sita ZSM-5 pripremljena metodom sinteze in-situ u čvrstoj fazi čisti zeolitni materijal skupine MFI. Kristaliničnost molekularnog sita ZSM-5 iznosila je 59,8 %. Sintetizirano molekularno sito ZSM-5 imalo je više kiseline i strukturu sa širokim porama. Prosječna veličina pora bila je 5,9 nm, a specifična površina (BET) i specifična površina mikropora uzoraka iznosile su 213 m2 g–1, odnosno 124 m2 g–1. Evaluirani rezultati ukazali su na to da aditiv katalizatora FCC pokazuje dobru selektivnost za ukapljeni naftni plin (UNP), propilen i buten, povećavajući prinos propilena i butena za 2,28 %, odnosno 2,15 %, kao i da ima bolju sposobnost krekiranja teškog ulja i selektivnost koksa. Ovo djelo je dano na korištenje pod licencom Creative Commons Imenovanje 4.0 međunarodna

    Adsorpcija Cu2+, Zn2+ i Ni2+ iona na adsorbens pripremljen iz potrošenog FCC katalizatora i kremenih diatomita

    Get PDF
    An adsorbent prepared from fluid catalytic cracking (FCC) spent catalyst fines and diatomite, and its adsorption of Cu2+, Zn2+, and Ni2+ ions were investigated. The adsorbent was characterized by XRD, SEM, and N2 adsorption-desorption techniques. The results showed that the specific surface area and pore volume of adsorbent increased with the increase in FCC spent catalyst fines. The influence factors on the adsorption of the adsorbents were studied. The suitable adsorption conditions were: pH value of 5.0, ratio of solid to liquid of 1 : 600 (g:ml), adsorption time of 4 h, room temperature. The adsorption of metal ions varied with the type of metal cations. The adsorption isotherms suggested that the sequence of the adsorption efficiency was Cu2+ > Zn2+ > Ni2+. The amount of Cu2+, Zn2+, and Ni2+ metal ion adsorbed onto the adsorbent was 49.17 mg g–1, 46.83 mg g–1, and 35.72 mg g–1, respectively. The adsorption data of Cu2+, Zn2+, and Ni2+ ions fitted well with the Freundlich adsorption isotherm model. This work is licensed under a Creative Commons Attribution 4.0 International License.Ispitivan je adsorbens pripremljen iz katalizatora za katalitičko krekiranje u vrtložnom sloju (FCC) i diatomita, te njegova adsorpcija iona Cu2+, Zn2+ i Ni2+. Adsorbens je karakteriziran XRD, SEM i N2 adsorpcijsko-desorpcijskim tehnikama. Rezultati su pokazali da se specifična površina i volumen pora adsorbensa povećavaju s povećanjem količine potrošenog katalizatora FCC. Proučavani su čimbenici utjecaja na adsorpciju adsorbensa. Prikladni uvjeti adsorpcije bili su: pH vrijednost 5,0, omjer čvrste tvari i kapljevine 1 : 600 (g:ml), vrijeme adsorpcije 4 h i sobna temperatura. Adsorpcija metalnih iona varira s tipom metalnih kationa. Adsorpcijske izoterme pokazale su da je slijed učinkovitosti adsorpcije Cu2+ > Zn2+ > Ni2+. Količina metalnih iona Cu2+, Zn2+ i Ni2+ adsorbiranih na adsorbensu iznosila je 49,17 mg g–1, 46,83 mg g–1, odnosno 35,72 mg g–1. Podatci o adsorpciji iona Cu2+, Zn2+ i Ni2+ slijede model Freundlichove adsorpcijske izoterme. Ovo djelo je dano na korištenje pod licencom Creative Commons Imenovanje 4.0 međunarodna

    IsaB Inhibits Autophagic Flux to Promote Host Transmission of Methicillin-Resistant Staphylococcus aureus.

    Get PDF
    Methicillin-resistant Staphylococcus aureus (MRSA) has emerged as a major nosocomial pathogen that is widespread in both health-care facilities and in the community at large, as a result of direct host-to-host transmission. Several virulence factors are associated with pathogen transmission to naive hosts. Immunodominant surface antigen B (IsaB) is a virulence factor that helps Staphylococcus aureus to evade the host defense system. However, the mechanism of IsaB on host transmissibility remains unclear. We found that IsaB expression was elevated in transmissible MRSA. Wild-type isaB strains inhibited autophagic flux to promote bacterial survival and elicit inflammation in THP-1 cells and mouse skin. MRSA isolates with increased IsaB expression showed decreased autophagic flux, and the MRSA isolate with the lowest IsaB expression showed increased autophagic flux. In addition, recombinant IsaB rescued the virulence of the isaB deletion strain and increased the group A streptococcus (GAS) virulence in vivo. Together, these results reveal that IsaB diminishes autophagic flux, thereby allowing MRSA to evade host degradation. These findings suggest that IsaB is a suitable target for preventing or treating MRSA infection
    • …
    corecore