190 research outputs found
Equilibrium, Kinetic and Thermodynamic studies of adsorption of cationic dyes from aqueous solution using ZIF-8
Zeolitic imidazolate framework-8 (ZIF-8) is one type of (MOFs) that has been synthesized and characterized and detailed analysis of Crystal violet (CV) and Malachite Green (MG) adsorption behaviour. Impact of different variables on batch method as a function of solution pH, concentration of CV and MG, dose of ZIF-8, Contact time and temperature were analyzed and optimal test conditions were determined. Scanning electron microscopy (SEM) was used to measure surface alterations of the ZIF-8. The surface area and volume of the pores were found to be 495.199 m2g–1 and 0.026 cm3g−1, respectively as determined by the Brunauer-Emmett-Teller (BET) test. ZIF-8 point of zero charging (pHPZC) was calculated and was found 7.9. Adsorption data were modeled on isotherms for adsorption of Langmuir, Freundlich, Dubinin–Radushkevich and Temkin. Equilibrium data from the adsorption processes showed that the Langmuir is fitted with CV and MG adsorption. Pseudo-first order, pseudo-second order, kinetic models Weber and Morris and Elovich were used to analyze the kinetic data obtained at different initial dye concentrations. The kinetics of adsorption showed that the action in adsorption adopted the processes of pseudo-second - order kinetic model and chemisorption. The thermodynamic parameter such as ∆G, ∆S and ∆H has been determined. Study of thermodynamics for adsorption indicated the reaction was endothermal and spontaneous
Pollutant Removal from Highway Runoff Using Retention/Detention Units
Highway runoff contains total suspended solids, hydrocarbons, oil and greases, chloride, and other contaminants that are transported in solution and particulate forms to adjacent floodplains, roadside swales, and retention/detention ponds. Oil and grit chambers represent a type of retention/detention unit used for removing heavy particulates and adsorbed hydrocarbon particulates. Storage/sediment units also represent a type of retention/detention unit used for controlling peak flow and removing suspended solids. The aim of this study is to evaluate the effect of traffic volume and site characteristics on highway runoff quality. The study also aims to evaluate the performance of retention/detention units that collect runoff from the Prague-Brno and Prague-Plzeň highways, Czech Republic. The results of this study indicate no definitive relationship between average daily traffic and concentration of runoff constituents, though the site characteristics have a strong relation to some constituents. The results also show that retention/detention units are effective in treating organic compounds
CLOVE OR GREEN TEA ADMINISTRATION ANTAGONIZES KHAT HEPATOTOXICITY IN RATS
Objective: Khat consumption has become a common problem that affects the health aspects of life in Yemen and other parts in the world. The liver has been suspected to be particularly vulnerable to the harmful effects of khat use and until now khat hepatotoxicity effects are still controversial. This study was conducted to investigate the hepatoprotective effects of aqueous extracts of clove and green tea, as medicinal herbs with established antioxidant properties, against controversial hepatotoxicity effects of khat in rats. Methods: Rats received a daily oral dose of khat extract alone or in combination with green tea or clove extract for six weeks. To study the effects on liver cells, histopathology, routine liver function tests, malondialdehyde (MDA), total antioxidant capacity (TAC) and the activities of superoxide dismutase (SOD) and catalase (CAT) enzymes were investigated. Results: Khat administration showed marked liver injury; congestion in the portal vein with fibrous tissue proliferation, extended from the portal area and forming intralobular Porto-portal bridging fibrous septae. Besides significant routine liver function tests alterations, lipid peroxides elevation, and TAC reduction with significant inhibition of SOD and CAT activities. Conclusion: Combined administration of khat with clove or green tea protected hepatocytes via oxidative stress inhibition. They significantly counteracted the alterations in liver function tests, decreased lipid peroxidation and restored the antioxidant status to near normal levels. These results confirm khat hepatotoxicity and suggest that clove or green tea administration has strong hepatoprotective effects against khat induced hepatotoxicity in rats via antioxidant mediated mechanism.Â
Comparative studies on the efficacy of lincomycin and bacitracin for the control of necrotic enteritis in broiler chickens
Background: The present study was conducted to evaluate the efficacy of lincomycin and/or bacitracin for control of experimentally-induced Clostridium perfringens (CP) infection in broiler chickens.Methods: A total of 100 one-day-old Cobb-mixed chicks were divided into five groups (A, B, C, D and E, each of 20 bird). At the 15th day of age, all birds (except group A) were inoculated orally with CP broth culture (109 CFU/mL). Two days later, drugs were orally administered once daily for five consecutive days as follow; Group A and B were left untreated. Group C, D, and E were treated with lincomycin (0.5 g/l), bacitracin (100 mg/l), lincomycin and bacitracin, respectively. The efficacy of used drugs was estimated based on clinical symptoms, body weight, weight gain, feed conversion rate. Hematobiochemical changes were also determined.Results: Necrotic enteritis in broiler chickens induced a significant decrease in body weight, weight gain, erythrocytic count, hemoglobin content, PCV %, serum proteins, catalase, and superoxide dismutase. Additionally, a marked decrease in serum lipids was obtained. Furthermore, a significant increase in feed conversion rate, leukocytic count, phagocytic activity, phagocytic index, serum total globulin, γ globulin and malondialdehyde coupled with a marked increase in β and α globulins were determined. Medication of infected broilers with lincomycin and/or bacitracin improved clinical signs and reduced mortality rate to 8, 6 and 2%, respectively, as well as restored the performance and hematobiochemical alterations.Conclusions: a combination of lincomycin and bacitracin was of considerable value for the control of necrotic enteritis in broiler chickens
Simulation: Early Detection of Brain Vessels Stroke by Applying Electromagnetic Waves Non-Invasively
Introduction: Early recognition of stroke with its two types Ischemic and Hemorrhagic, is one of the most crucial research points, commonly used methods are CT- (computerized tomography), and MRI- (Magnetic resonance imaging). These techniques cause a delay in the detection of the condition, which causes permanent disability. The main reason behind the fatal consequences of stroke is the delay of detection. Therefore, this research paper aims to early detection of the type of stroke without delay until the appropriate diagnosis of each type is made, and then the appropriate treatment without delay.
Method: Using a non-invasive and fast technique to determine the stroke type by wave, we simulate and design a vessel containing a liquid as a laminar flow with the same density and velocity of blood, and it was surrounded by a Homogenized multi-turn coil consisting of (n) turns to represent the magnetic field, using specific frequency (HZ) with Electrical field in coil current (A) to see the changing in magnetic flux density (MFD), Depending on the changes in MFD, the flow of blood in laminar flow can be affected by clotting (Ischemic) or Hemorrhagic (cutting) in our vessel designed. We have built three different scenarios to apply the technique which are: First: Normal Scenario (where the blood in vessel has no problem), second: clotting (ischemic, where the vessel blocked in specific three position) and Third: Cutting (Hemorrhagic, where the vessel cut in certain nine positions).
Results: This paper presents-through our own design-the studying of applying the electromagnetic waves on blood inside the vessel to detect the stroke type in our three scenarios (normal, ischemic three positions or hemorrhagic nine positions), Studying the magnetic field and laminar flow. This study covered in three areas. First: coil geometry analysis, Second: stationary, and Third: frequency domain. through the changes in Magnetic Flux Density -MFD- waves. The results were promising and distinct for distinguishing between the three scenarios which are normal, ischemic (3 positions) and hemorrhagic (9 positions) the results of MFD are: 0.09 to 3.3*10^-3, 0.08 to 3.15*10^-4, 0.15 to 6.2*10^-3 respectively
Influencia de distintas fuentes de sílice en las propiedades físicas y mecánicas de materiales derivados del yeso
Gypsum plaster/silica composites prepared by dry blending (0.2-10 %) natural sand, silica fume or silica gel and subsequently hydrated. Their physical and mechanical properties, including normal consistency, setting time, apparent porosity, bulk density and compressive strength, were determined after hydration for 7- and 28-days. The results indicated that adding different forms of silica lowered the bulk density and increased the normal consistency, setting time, apparent porosity and, to some limited extent, compressive strength of the composites. This improvement in properties can be attributed to the existence of silica in the interstitial pores in the hardened plaster matrices. While most of the composites revealed only scant rises in compressive strength, their composition was beneficial in so far as it included either a readily available low-cost constituent (sand) or industrial by-products. Consequently, the formed plaster-silica composites are of economic value, contribute to a cleaner environment by minimizing waste and can be used for applications where high porosity, lightweight units are required or recommended for low-cost buildings.Se prepararon pastas compuestas de yeso y sílice mediante la mezcla en seco de yeso con distintas proporciones (0,2- 10 %) de arena natural, o gel o humo de sílice, procediéndose a continuación a su hidratación. A fin de determinar las propiedades físicas y mecánicas de las pastas, a los 7 y los 28 días de hidratación se hallaron su fluidez, tiempo de fraguado, porosidad aparente, densidad aparente y resistencia a la compresión. Los resultados obtenidos indican que al incorporar las distintas modalidades de sílice a la mezcla, disminuyó la densidad aparente y aumentaron la fluidez, el tiempo de fraguado, la porosidad aparente y, en menor medida, la resistencia a la compresión de las muestras. Se considera que esta mejora de las propiedades del material se debe a la presencia de sílice en los poros intersticiales de las matrices endurecidas de yeso. Aunque la resistencia a la compresión de la mayoría de las pastas ensayadas apenas aumentó, estas se beneficiaron de la presencia en su composición de elementos de bajo coste como la arena o los distintos subproductos industriales utilizados. Puede concluirse, por lo tanto, que los compuestos de yeso y sílice tienen valor económico y contribuyen a mejorar el medioambiente al valorizar residuos. Por otra parte, son apropiados para las aplicaciones en las que se necesitan o recomiendan elementos de alta porosidad y bajo peso, concretamente en las edificaciones bajas
Modelling of Highway Runoff Quantity and Quality
The stormwater Management Model (SWMM) is a well-known stormwater runoff-simulation model. It is a deterministic, spatially distributed model for calculation of runoff quantity and quality. The aim of this study was to predict highway runoff characteristics using data from different highway catchments. The SWMM was used in the simulation process and the predicted data was verified using monitoring data collected from Prague-Plzeň highway for both total suspended solids and organic compounds. The analyzed data indicated that the simulated TSS, BOD5 concentrations lie within the range of the measured data and both data sets are considered highly polluted with respect to the specification limits. The analyzed data also show that the first flush of runoff is the most polluted, and is responsible for contamination of retention and/or received waters
Correlation between Uterine Hemodynamics, Sex Steroid Hormone Concentrations, and Enzymatic Antioxidant Levels in Postpartum Buffaloes
The present investigation aimed to evaluate uterine hemodynamics in six multiparous postpartum buffaloes and their relationship with sex steroid hormone concentrations and enzymatic antioxidant levels. The buffaloes were examined by transrectal Doppler ultrasonography to record the vascular perfusion in uterine arteries of both ipsilateral and contralateral ones. All Doppler indices such as peak (PV) endpoints (EV) of velocity, peak systolic velocity (PSV), blood flow volume (BFV), resistance (RI), and pulsatility index (PI) were recorded from 1st to 6th postpartum. The blood samples were collected starting from 1st-week post-calving and every week thereafter following each ultrasound Doppler examination for assay of steroid hormones (progesterone and estradiol) and antioxidant (superoxide dismutase (SOD), glutathione peroxidase (GPX), and catalase, CAT) were measured. PV of the ipsilateral previously gravid arteries showed a linear pattern of significant (P=0.001) decline from the 1st week after parturition till the 6th week. This decline was also associated with a linear decrease in EV from the 1st week till the 6th week after birth. While contralateral PV and EV are not significantly changed throughout weeks after parturition. The levels of SOD and CAT are significantly elevated at 1st week postpartum compared to the 6th week after parturition. In contrast, the GPx levels did not reveal any significant differences during the puerperal period. Estradiol and progesterone declined from 1st to 5th week after parturition. PV of the ipsilateral uterine artery had a significant (P≤0.05) positive correlation with BFV (r=0.49), estradiol 17- α(r=0.98) and progesterone (r=0.85). The same parameter showed a statically (P≤ 0.001) positive correlation with SOD (r=0.87) and CAT (r=0.92). While, Ipsilateral uterine RI showed a significant (P≤0.05) negative correlation with PV(r=-0.85), BFR ((r=-0.62), estradiol 17- α(r=-0.52), and progesterone (r=-0.88), in addition, RI also correlated negatively with both SOD (r=-0.57) and CAT (r=-0.63). Progesterone and estrogen levels are strongly correlated with SOD and CAT. The uterine hemodynamics in buffaloes is affected by the day of the postpartum period. SOD and CAT antioxidants recorded herein, except GPx, increase in the 1st weeks of calving and are affected by the day of the postpartum period
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