Three dimensional adaptive method for compressible multi-fluids flows

In this paper, a hexahedral-mesh based solution adaptive algorithm for the simulation of compressible multi-fluid flows is proposed. The data structure, the refinement and coarsening process, and the solution adaptive method are described. The cells with different levels are stored in different lists. This avoids the recursive calculation of solution of mother (non-leaf) cells. Besides, the faces are separated stored into two lists: one for leaf faces and another for non-leaf faces. Thus, high efficiency is obtained due to these features. Numerical results show that there is no oscillation of pressure and velocity across the interface and it is feasible to apply it to solve compressible multi-fluid flows with large density ratio (1000) and strong shock wave interaction with the interface

Properties of the FCC Catalyst Additive Prepared from Guizhou Kaoline

The properties of a FCC catalyst additive prepared from Guizhou kaoline were extensively investigated. The samples were characterized by N<sub>2 adsorption, X-ray diffraction, IR spectrometry, and scanning electron microscope (SEM). The results showed that the crystallinity of NaY zeolite synthesized from this kaoline was 25% and the silica alumina ratio was _{rk/s ˇ m}= 5.05. The catalyst additive prepared from above crystallization product exhibited excellent performance of nickel and vanadium passivation, offered 21% lower coke versus base catalyst, while maintaining high bottoms upgrading selectivity

Svojstva aditiva FCC katalizatora pripravljenih iz Guizhou kaolina

The properties of a FCC catalyst additive prepared from Guizhou kaoline were extensively investigated. The samples were characterized by N2 adsorption, X-ray diffraction, IR spectrometry, and scanning electron microscope (SEM). The results showed that the crystallinity of NaY zeolite synthesized from this kaoline was 25% and the silica alumina ratio was rk/s ˇ m = 5.05. The catalyst additive prepared from above crystallization product exhibited excellent performance of nickel and vanadium passivation, offered 21% lower coke versus base catalyst, while maintaining high bottoms upgrading selectivity.U radu su opisana istraživanja svojstava aditiva FCC-katalizatora pripravljenih iz Guizhou kaolina. Aditivi su karakterizirani adsorpcijom N2, rengenskom difrakcijom praškastih uzoraka, IR-spektroskopijom i pretražnom elektronskom mikroskopijom. Rezultati ukazuju da kristaliničnost zeolita NaY pripravljenog iz Guizhou kaolina iznosi 25% te da je omjer silicijevog oksida (SiO2) i aluminijevog oksida (Al2O3) 5,05 (mol/mol). Aditiv iskazuje prestižna svojstva FCC-katalizatora prvenstveno pasivizacije nikla i vanadija, proizvodi 21% manje koksa, i održava visoku selektivnost destilacijskih ostataka

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

Potpuno iskorištavanje taloga preostalog nakon priprave zeolitskog katalizatora

A novel utilization method of filter residue from the preparation process of zeolite-based catalysts was investigated. Y zeolite and a fluid catalytic cracking (FCC) catalyst were synthesized from filter residue. Compared to the Y zeolite synthesized by the conventional method, the Y zeolite synthesized from filter residue exhibited better thermal stability. The catalyst possessed wide-pore distribution. In addition, the pore volume, specific surface area, attrition resistance were superior to those of the reference catalyst. The yields of gasoline and light oil increased by 1.93 and 1.48 %, respectively. At the same time, the coke yield decreased by 0.41 %. The catalyst exhibited better gasoline and coke selectivity. The quality of the cracked gasoline had been improved.Proučena je upotreba taloga preostalog nakon priprave katalizatora baziranog na zeolitima. Od taloga su pripravljeni zeolit Y i katalizator za katalitičko krekiranje u fluidiziranom sloju (FCC). Ovako sintetiziran zeolit Y termički je stabilniji u odnosu na zeolit Y sintetiziran konvencionalnom metodom. Katalizator ima široku distribuciju veličine pora. U odnosu na referentni katalizator pokazuje veći obujam pora i specifičnu površinu te bolju otpornost na atriciju. Iskorištenje benzina i lakog ulja povećalo se za 1,93 i 1,48 %, a koksa smanjilo za 0,41 %. Katalizator je pokazao bolju selektivnost s obzirom na benzin i koks, a poboljšala se kvaliteta krekiranog benzina

Cobrotoxin from Naja naja atra

Chronic kidney disease (CKD) becomes a global health problem with high morbidity and mortality. Adriamycin- (ADR-) induced rodent chronic nephropathy is a classic experimental model of human minimal lesion nephrotic syndrome. The present study investigated the effect of cobrotoxin (CTX) on ADR-induced nephropathy. Rats were given 6 mg/kg ADR once through the tail vein to replicate ADR nephropathy model. CTX was administered to rats daily by placing a fast dissolving CTX membrane strip under the tongue starting from 5 days prior to ADR administration until the end of experiment. The results showed that CTX ameliorated the symptoms of ADR nephropathy syndrome with reduced body weight loss, proteinuria, hypoalbuminemia, dyslipidemia, serum electrolyte imbalance, oxidative stress, renal function abnormities, and kidney pathological lesions. Anti-inflammatory cytokine IL-10 expression was elevated after CTX administration in ADR nephropathy model. CTX inhibited the phosphorylation of IκB-α and NF-κB p65 nuclear translocation. Meanwhile, CTX upregulated the protein level of podocyte-specific nephrin and downregulated the level of fibrosis-related TGF-β. These findings suggest that CTX may be a potential drug for chronic kidney diseases

Klinička primjena RT-PCR u otkrivanju DNK tuberkuloze u kombinaciji s TB-IGRA u dijagnostici plućne tuberkuloze s negativnim nalazom sputuma

The aim was to investigate detection of pulmonary alveolar lavage fluid tuberculosis DNA by real-time fluorescent polymerase chain reaction (RT-PCR) combined with clinical application of the sputum smear-negative pulmonary tuberculosis diagnosis with TB interferon-γ release assay (TB-IGRA). From October 2014 to October 2015, 632 outpatients and inpatients treated in our hospital were randomly selected, of which 459 patients as the research group managed with RT-PCR detection combined with TB-IGRA and 173 patients as the control group undergoing electronic bronchoscopy alveolar lavage fluid detection, with detection results statistically evaluated. The positive rate in the research group was 96.51%, i.e. significantly higher than that in the control group (66.47%), yielding a statistically significant difference (χ2=109.68, p=0.00). The true positive rate was 97.7% in the research group and 67.92% in the control group; the true positive rate was significantly higher in the research group patients as compared with the control group, yielding a statistically significant difference (χ2=112.04, p=0.00). The sensitivity and specificity, as well as Youden index were significantly higher in the research group as compared with the control group. In conclusion, TB DNA detection by RT-PCR combined with TB-IGRA is a very good method of diagnosing tuberculosis, and it can be implemented in clinical diagnosis of pulmonary tuberculosis.Cilj istraživanja bio je ispitati otkrivanje DNK tuberkuloze u plućnom alveolarnom ispirku pomoću lančane reakcije polimeraze u stvarnom vremenu s fluorescentnim bojama (RT-PCR) u kombinaciji s kliničkom primjenom dijagnostike plućne tuberkuloze s negativnim nalazom sputuma pomoću testa otpuštanja TB interferona-γ (TB-IGRA). Od listopada 2014. do listopada 2015. godine nasumce su odabrane 632 osobe bolnički i izvanbolnički liječene u našoj bolnici, od kojih je 459 uključeno u ispitnu skupinu podvrgnutu otkrivanju pomoću RT-PCR u kombinaciji s testom TB-IGRA, a 173 u kontrolnu skupinu podvrgnutu elektroničkom otkrivanju u bronhoskopskom alveolarnom ispirku; rezultati su statistički obrađeni. Stopa pozitivnih nalaza bila je 96,51% u ispitnoj skupini, odnosno značajno viša od one u kontrolnoj skupini (66,47%), uz statistički značajnu razliku (χ2=109,68; p=0,00). Stopa stvarno pozitivnih nalaza bila je 97,7% u ispitnoj skupini i 67,92% u kontrolnoj skupini, dakle značajno viša kod bolesnika ispitne skupine u usporedbi s kontrolnom skupinom, uz statistički značajnu razliku (χ2=112,04; p=0,00). Osjetljivost i specifičnost, kao i Youdenov indeks bili su značajno viši u ispitnoj skupini u usporedbi s kontrolnom skupinom. U zaključku, otkrivanje TB DNK pomoću RT-PCR u kombinaciji s TB-IGRA vrlo je dobra metoda za dijagnosticiranje tuberkuloze, koja se može primjenjivati u kliničkoj dijagnostici plućne tuberkuloze

Characterization of Chemical Composition of Pericarpium Citri Reticulatae Volatile Oil by Comprehensive Two-Dimensional Gas Chromatography with High-Resolution Time-of-Flight Mass Spectrometry

Pericarpium Citri Reticulatae (Chenpi in Chinese) has been widely used as an herbal medicine in Korea, China, and Japan. Chenpi extracts are used to treat indigestion and inflammatory syndromes of the respiratory tract such as bronchitis and asthma. This thesis will analyze chemical compositions of Chenpi volatile oil, which was performed by comprehensive two-dimensional gas chromatography with high-resolution time-of-flight mass spectrometry (GC × GC-HR-TOFMS). One hundred and sixty-seven components were tentatively identified, and terpene compounds are the main components of Chenpi volatile oil, a significant larger number than in previous studies. The majority of the eluted compounds, which were identified, were well separated as a result of high-resolution capability of the GC × GC method, which significantly reduces, the coelution. β-Elemene is tentatively qualified by means of GC × GC in tandem with high-resolution TOFMS detection, which plays an important role in enhancing the effects of many anticancer drugs and in reducing the side effects of chemotherapy. This study suggests that GC × GC-HR-TOFMS is suitable for routine characterization of chemical composition of volatile oil in herbal medicines