Numerical Simulation of Non-Homogeneous Viscous Debris-Flows Based on the Smoothed Particle Hydrodynamics (SPH) Method

Non-homogeneous viscous debris flows are characterized by high density, impact force and destructiveness, and the complexity of the materials they are made of. This has always made these flows challenging to simulate numerically, and to reproduce experimentally debris flow processes. In this study, the formation-movement process of non-homogeneous debris flow under three different soil configurations was simulated numerically by modifying the formulation of collision, friction, and yield stresses for the existing Smoothed Particle Hydrodynamics (SPH) method. The results obtained by applying this modification to the SPH model clearly demonstrated that the configuration where fine and coarse particles are fully mixed, with no specific layering, produces more fluctuations and instability of the debris flow. The kinetic and potential energies of the fluctuating particles calculated for each scenario have been shown to be affected by the water content by focusing on small local areas. Therefore, this study provides a better understanding and new insights regarding intermittent debris flows, and explains the impact of the water content on their formation and movement processes

Zelena sinteza i primjena zeolita ZSM-5

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

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

SjTPdb: integrated transcriptome and proteome database and analysis platform for Schistosoma japonicum

<p>Abstract</p> <p>Background</p> <p><it>Schistosoma japonicum </it>is one of the three major blood fluke species, the etiological agents of schistosomiasis which remains a serious public health problem with an estimated 200 million people infected in 76 countries. In recent years, enormous amounts of both transcriptomic and proteomic data of schistosomes have become available, providing information on gene expression profiles for developmental stages and tissues of <it>S. japonicum</it>. Here, we establish a public searchable database, termed SjTPdb, with integrated transcriptomic and proteomic data of <it>S. japonicum</it>, to enable more efficient access and utility of these data and to facilitate the study of schistosome biology, physiology and evolution.</p> <p>Description</p> <p>All the available ESTs, EST clusters, and the proteomic dataset of <it>S. japonicum </it>are deposited in SjTPdb. The core of the database is the 8,420 <it>S. japonicum </it>proteins translated from the EST clusters, which are well annotated for sequence similarity, structural features, functional ontology, genomic variations and expression patterns across developmental stages and tissues including the tegument and eggshell of this flatworm. The data can be queried by simple text search, BLAST search, search based on developmental stage of the life cycle, and an integrated search for more specific information. A PHP-based web interface allows users to browse and query SjTPdb, and moreover to switch to external databases by the following embedded links.</p> <p>Conclusion</p> <p>SjTPdb is the first schistosome database with detailed annotations for schistosome proteins. It is also the first integrated database of both transcriptome and proteome of <it>S. japonicum</it>, providing a comprehensive data resource and research platform to facilitate functional genomics of schistosome. SjTPdb is available from URL: <url>http://function.chgc.sh.cn/sj-proteome/index.htm</url>.</p