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1.
Sci Rep ; 14(1): 7910, 2024 Apr 04.
Article in English | MEDLINE | ID: mdl-38575684

ABSTRACT

The Darcy-Forchheimer model is a commonly used and accurate method for simulating flow in porous media, proving beneficial for fluid separation, heat exchange, subsurface fluid transfer, filtration, and purification. The current study aims to describe heat and mass transfer in ternary nanofluid flow on a radially stretched sheet with activation energy. The velocity equation includes Darcy-Fochheimer porous media effects. The novelty of this study is enhanced by incorporating gyrotactic microorganisms which are versatile and in nanofluid can greatly improve the thermal conductivity and heat transfer properties of the base fluid, resulting in more efficient heat transfer systems. Furthermore, the governing PDEs are reduced to ODEs via appropriate similarity transformations. The influence of numerous parameters is expanded and physically depicted through the graphical illustration. As the Forchheimer number escalates, so do the medium's porosity and drag coefficient, resulting in more resistive forces and, as a result, lowering fluid velocity. It has been discovered that increasing the exponential heat source/sink causes convective flows that are deficient to transport heat away efficiently, resulting in a slower heat transfer rate. The concentration profile accumulates when the activation energy is large, resulting in a drop in the mass transfer rate. It is observed that the density of motile microorganisms increases with a rise in the Peclet number. Further, the results of the major engineering coefficients Skin-friction, Nusselt number, Sherwood number, and Microorganism density number are numerically examined and tabulated. Also, the numerical outcomes were found to be identical to the previous study.

2.
Stud Health Technol Inform ; 245: 1272, 2017.
Article in English | MEDLINE | ID: mdl-29295357

ABSTRACT

We examined depression, impulse control disorder, and life style by degree of smartphone addiction. Chi-square tests and ANOVA were used to identify significant variables. CART was used to generate a decision making diagram of variables affecting smartphone addiction. The severe smartphone addiction group had rates of depression and impulse control disorder than the initial smartphone group.


Subject(s)
Behavior, Addictive , Depression , Disruptive, Impulse Control, and Conduct Disorders , Smartphone , Humans , Life Style
3.
Luminescence ; 32(5): 772-778, 2017 Aug.
Article in English | MEDLINE | ID: mdl-27860121

ABSTRACT

A trivalent rare-earth ion (Sm3+ )-doped LiNa3 P2 O7 (LNPO) phosphor was synthesized using a conventional high-temperature solid-state reaction route. A predominant orthorhombic phase of LNPO was observed in all X-ray diffraction patterns. The surface states of the LNPO:Sm phosphor were confirmed by X-ray photoelectron spectroscopy. Under 401 nm excitation, the Sm-doped LNPO phosphors showed sharp emission peaks at 563, 600 and 647 nm that are related to the f-f transition of Sm3+ ions. The optimum concentration of Sm3+ (9 mol%) produced Commission Internationale de l'Eclairage chromaticity coordinates, color rendering index and correlated color temperature of (0.564, 0.434), 42 and 1843 K, respectively.


Subject(s)
Diphosphates/chemistry , Luminescent Agents/chemistry , Color , Diphosphates/chemical synthesis , Luminescent Agents/chemical synthesis , Luminescent Measurements , Microscopy, Electron, Scanning , Photoelectron Spectroscopy , Samarium/chemistry , Spectrophotometry, Ultraviolet , Spectroscopy, Fourier Transform Infrared , X-Ray Diffraction
4.
J Nanosci Nanotechnol ; 14(9): 6950-6, 2014 Sep.
Article in English | MEDLINE | ID: mdl-25924354

ABSTRACT

In this study, Yb-doped ZnSe nanoparticles were synthesized by co-reduction method at 150 degrees C and pH = 12 for 24 h. The obtained materials were characterized by X-ray diffraction (XRD), UV-Vis diffuse reflectance spectroscopy (DRS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Powder XRD patterns indicated that the Yb(x)Zn(1-x)Se crystals (x = 0.00-0.10) are isostructural with ZnSe. SEM and TEM images confirmed doping of Yb3+ into the lattice of ZnSe nanoparticles. The UV-Vis diffuse reflectance characteristics of the Yb-doped ZnSe samples were quite similar to that of the undoped sample and showed a strong photoabsorption at visible light range. The electrical conductivity of Yb-doped ZnSe nanomaterials was higher than pure ZnSe at room temperature, and increased with temperature. The photocatalytic activity of synthesized nanoparticles was investigated by the degradation of Orange II solution under visible light irradiation. It was observed that the color removal efficiency of Yb-doped ZnSe catalyst was much higher than that of pure ZnSe (26.28 and 77.10% after 120 min of treatment for ZnSe and Yb(0.06)Zn(0.94)Se, respectively). The results demonstrated the good photocatalytic ability of synthesized nanoparticles under visible light. Also, it was revealed that the decolorization efficiency of Orange II over Yb-doped ZnSe increased with increasing Yb loading up to 6 mol% and then decreased.

5.
Spectrochim Acta A Mol Biomol Spectrosc ; 122: 737-43, 2014 Mar 25.
Article in English | MEDLINE | ID: mdl-24374931

ABSTRACT

A novel, rapid and sensitive CuO nanosheets (NSs) amplified flow-injection chemiluminescence (CL) system, luminol-H2O2-CuO nanosheets, was developed for determination of the vancomycin hydrochloride for the first time. It was found that vancomycin could efficiently inhibit the CL intensity of luminol-H2O2-CuO nanosheets system in alkaline medium. Under the optimum conditions, the inhibited CL intensity was linearly proportional to the concentration of vancomycin over the ranges of 0.5-18.0 and 18.0-40.0 mg L(-1), with a detection limit (3σ) of 0.1 mg L(-1). The precision was calculated by analyzing samples containing 5.0 mg L(-1) vancomycin (n=11) and the relative standard deviation (RSD) was 2.8%. Also, a high injection throughput of 120 sample h(-1) was obtained. The CuO nanosheets were synthesized by a sonochemical method. Also, X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses were employed to characterize the CuO nanosheets. The method was successfully employed to determine vancomycin hydrochloride in environmental water samples, pharmaceutical formulation and spiked human serum.


Subject(s)
Anti-Bacterial Agents/analysis , Anti-Bacterial Agents/blood , Copper/chemistry , Nanostructures/chemistry , Vancomycin/analysis , Vancomycin/blood , Flow Injection Analysis/methods , Humans , Hydrogen Peroxide/chemistry , Limit of Detection , Luminescent Measurements/methods , Luminol/chemistry , Pharmaceutical Preparations/chemistry , Water/analysis , X-Ray Diffraction
6.
J Nanosci Nanotechnol ; 13(7): 5109-14, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23901537

ABSTRACT

In the present study, self-cleaning and mechanical properties of white Portland cement by addition of commercial available TiO2 nanoparticles with the average particle size of 80 nm were investigated. X-ray diffraction (XRD), transmission electron microscopy (TEM) and BET were used to characterize TiO2 nanoparticles. For determination of self-cleaning properties of TiO2-modified white cement, colorimetric tests in decolorization of C.I. Basic Red 46 (BR46) in comparison to unmodified cement samples was applied. The results indicated that with increasing the amount of TiO2 nanoparticles in modified cement, self-cleaning property of the samples increased. The mechanical properties of TiO2-modified and unmodified cement samples, such as time of setting of hydraulic cement, compressive strength of hydraulic cement mortar and flexural strength of hydraulic cement mortar were examined. The results indicated that addition of TiO2 nanoparticles up to maximum replacement level of 1.0% improved compressive and flexural strength and decreased its setting time.


Subject(s)
Cementation/methods , Construction Materials , Crystallization/methods , Nanostructures/chemistry , Nanostructures/ultrastructure , Titanium/chemistry , Elastic Modulus , Hardness , Macromolecular Substances/chemistry , Materials Testing , Molecular Conformation , Particle Size , Surface Properties
7.
Article in English | MEDLINE | ID: mdl-23659949

ABSTRACT

In this study, the photocatalytic degradation of a mixture of three pharmaceuticals, Metronidazole (MET), Atenolol (ATL) and Chlorpromazine (CPR), was quantified simultaneously during the UV/TiO2 process. The investigated TiO2 was Millennium PC-500 immobilized on ceramic plates by sol-gel based method. The partial least squares modeling was successfully applied for the multivariate calibration of the spectrophotometric data. The central composite design was applied to model and optimize the UV/TiO2 process. Predicted values of removal efficiency were found to be in good agreement with experimental values for MET, ATL and CPR (R(2)=0.947 and Adj-R(2)=0.906, R(2)=0.977 and Adj-R(2)=0.960 and R(2)=0.982 and Adj-R(2)=0.969, respectively). The optimum initial concentration of pharmaceuticals, reaction time and UV light intensity was found to be 10 mg L(-1), 150 min and 38.45 W m(-2), respectively. The main degradation intermediates of pharmaceuticals produced in this process were identified by GC-MS technique. The chronic ecotoxicity of pharmaceuticals was evaluated using aquatic species Spirodela polyrrhiza prior to and after photocatalysis. The TOC results (90% removal after 16 h) and ecotoxicological experiments revealed that the photocatalysis process could effectively mineralize and reduce the ecotoxicity of the pharmaceuticals from their aqueous solutions.


Subject(s)
Atenolol/chemistry , Chlorpromazine/chemistry , Metronidazole/chemistry , Nanoparticles/chemistry , Photolysis , Titanium/chemistry , Water Pollutants, Chemical/chemistry , Araceae/drug effects , Atenolol/toxicity , Catalysis , Chlorpromazine/toxicity , Metronidazole/toxicity , Ultraviolet Rays , Water Pollutants, Chemical/toxicity
8.
Talanta ; 107: 263-9, 2013 Mar 30.
Article in English | MEDLINE | ID: mdl-23598221

ABSTRACT

A novel selenium nanoparticles (Se NPs)-amplified chemiluminescence (CL) reaction, Se NPs-potassium permanganate-dinitrobutylphenol (DNBP), for the determination of DNBP at gram per milliliter level is described. In the present study, it was found that direct reaction of DNBP with potassium permanganate (KMnO4) in the acidic mediums elicited light emission, which was greatly enhanced by selenium nanoparticles. Under optimum conditions, the CL intensity is linearly related to the concentration of DNBP in the range of 1.0×10(-7)-8.0×10(-5)g mL(-1) with a detection limit (3σ) of 3.1×10(-8) g mL(-1). The relative standard deviation for 11 determinations of 2.5×10(-5) gm L(-1) DNBP is 2.07%. The Se NPs were prepared by the chemical hydrothermal method. It was found that catalytic properties of Se NPs were higher than those of microparticles (MPs). In addition, scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to characterize the Se NPs. Appropriate sensitivity, selectivity and precision were among notable features of the proposed method. The method was successfully applied to the determination of DNBP in the water samples of different origins. Moreover, the possible mechanism for the new CL reaction was also discussed.


Subject(s)
2,4-Dinitrophenol/analogs & derivatives , Luminescent Measurements/methods , Nanoparticles/chemistry , Pesticides/analysis , Selenium/chemistry , Water Pollutants, Chemical/analysis , 2,4-Dinitrophenol/analysis , Fresh Water/analysis , Limit of Detection , Luminescence , Nanoparticles/ultrastructure , Potassium Permanganate/chemistry
9.
Colloids Surf B Biointerfaces ; 106: 151-7, 2013 Jun 01.
Article in English | MEDLINE | ID: mdl-23434705

ABSTRACT

A novel rapid green one-step method is developed for the preparation of bio-silica coated with amorphous MnO2 nanoparticles by treating bio-silica with an acidic permanganate solution. The method developed has the advantage of selectively coating the surface of either one or both sides of the porous silica structure with a thin catalytic active amorphous MnO2 layer in a controlled way. The uncoated and MnO2 coated bio-silica are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The catalytic activity of amorphous MnO2-coated bio-silica is examined by degrading organic dye at ambient condition. The as-synthesized samples show highly efficient and rapid degradation of Rhodamine B. The simplicity and cost-effectiveness of the materials and method can be very useful for highly efficient degradation of organic pollutants for environmental remediation.


Subject(s)
Environmental Pollutants/chemistry , Manganese Compounds/chemistry , Organic Chemicals/chemistry , Oxides/chemistry , Silicon Dioxide/chemistry , Catalysis , Environmental Restoration and Remediation/methods , Metal Nanoparticles , Microscopy, Electron, Scanning , Microscopy, Electron, Transmission , X-Ray Diffraction
10.
Colloids Surf B Biointerfaces ; 102: 766-71, 2013 Feb 01.
Article in English | MEDLINE | ID: mdl-23107954

ABSTRACT

Monosized sodium alginate microdroplets are prepared using a flow-focusing microdevice by adjusting the flow rate of the continuous phase (soybean oil) and the dispersed phase (sodium alginate solution). The gelation process of the semi-product, sodium alginate microdroplets, occurs outside the channel in a calcium chloride solution to form tadpole-shaped calcium alginate microparticles. The microparticles prepared are in the range of 100-250 µm in diameter, depending on the experimental conditions. The shape, size and size distribution of these calcium alginate microparticles depend strongly on the calcium solution concentration and the stirring mode. The shaping mechanism of the microparticles and the impact of the experimental conditions on particle shape and size are investigated.


Subject(s)
Alginates/chemistry , Glucuronic Acid/chemistry , Hexuronic Acids/chemistry , Microfluidic Analytical Techniques
11.
Acta Radiol ; 36(5): 510-4, 1995 Sep.
Article in English | MEDLINE | ID: mdl-7640096

ABSTRACT

UNLABELLED: PURPOSE AND MATERIAL AND METHODS: MR findings of 9 surgically proven tubo-ovarian abscesses were analyzed in 8 patients. The images were evaluated for signal intensity characteristics and morphologic appearance of the mass, and presence of secondary changes in adjacent pelvic organs and structures. RESULTS: The signal intensity of the lesions on T1-weighted images was hypointense to the surrounding muscle and myometrium in 5 patients, isointense in 3 and hyperintense in 1. On T2-weighted images the signal intensity was hyperintense (n = 6) or heterogeneous (n = 3). A thin rim (1-3 mm) with hyperintensity on T1-weighted images was noted in the innermost aspect of the masses. Other findings were ill-defined margin, thickened wall, multiple internal septa, shading and gas collection. "Mesh-like" linear strands were noted in the pelvis in all patients, with involvement of adjacent pelvic organs in 7 and lymphadenopathy in 3. CONCLUSIONS: In this limited number of cases MR imaging showed great potential for demonstrating the extent of the disease, characterizing the lesions and making a specific diagnosis.


Subject(s)
Abdominal Abscess/diagnosis , Fallopian Tube Diseases/diagnosis , Magnetic Resonance Imaging , Ovarian Diseases/diagnosis , Adult , Aged , Contrast Media , Female , Gadolinium , Gadolinium DTPA , Humans , Middle Aged , Organometallic Compounds , Pentetic Acid/analogs & derivatives
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