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The electronic properties of carbon nanotubes CNTs, such as ionization potential (IP), electron affinity (EA), energy gap (Eg), Fermi energy (Ef), binding energy (Eb), the density of state (DOS), and IR spectral properties, investigated after substituted the OH, SO, SiO2, H2O, and N2 groups on the optimization structure of CNT (3,3). The lengths of C=C for zigzag CNT (3,3) slight altered with substituted the mention groups and given the depress in bond length during the substituted –OH, -SO, and –SiO2 that attitude to bond orders for these substituted groups and different in electronegativity power for an oxygen atom in these groups. Moreover, the C-C bond for zigzag CNT (3,3) changed also, and gave a slight increase during the substituted OH group, but decreased during substituted So and SiO2 groups. The substituted of –SO and –SiO2 on the structure of CNT (3,3) demonstrated, fewer values of total energies that will increase the stability of CNT. The CNTS-SiO2 has a less value for bandgap compared with other substituted materials, this behaver has given it a good electronic conductivity. The B3LYP functional theory has been used to conduct the DFT approach. The analyzed Nano species agree well with the experimental results based on the measured values of HOMO and LUMO energies. The Gaussian 09 program was used to calculate all feature values.

Reduced graphene oxide (RGO) has been commonly used as an additive in the optoelectronic devices account to its unique properties. Here, we added 6% of RGO into mesoporous titanium dioxide (mp-TiO2) to improve the performance of perovskite solar cells (PSCs). The RGO addition resulting in enhanced the crystal structure and optical absorbance of the corresponding perovskite film. The charge transport also was improved and recombination processes reduced due to better interfacial perovskite/mp-TiO2 contact. With this treatment, the optimized PSC achieved a power conversion efficiency of 14%. Most important, the humid long-term stability was improved after using RGO additive. PSCs with RGO maintained about 90% of their original performance after storage in ambient air with a relative humidity of 30-50%.

In this paper, we report the formation of new conjugates constituting single-wall nanotube (SWNTs) and multi-wall nanotube (MWNTs) comprising silver-doped titanium dioxide (TiO2/Ag) having outstanding antimicrobial and toxic properties. At first, the raw SWNTs and raw MWNTs were chemically treated with sulfuric acid and nitric acid to produce functionalized SWNTs (F-SWNTs) and functionalized MWNTs (F-MWNTs) surface. Then TiO2/Ag nanoparticles (NPs) were loaded with F-SWNTs and F-MWNTs using in situ sol–gel technique. The raw SWNTs, raw MWNTs, and conjugates’ samples were characterized via ultraviolet–visible (UV–Vis) spectrophotometer, Fourier transform infrared (FTIR), Raman spectroscopy, field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). These measurements confirmed the loading of TiO2/Ag NPs on SWNTs and MWNTs walls. The optical band gap of R-SWNTs and R-MWNTs was decreased from 3.74 to 3.6 eV and from 3.9 to 3.64 eV, respectively, after decoration of TiO2/Ag. The XRD results confirmed the hexagonal structure of R-SWNTs and R-MWNTs with (002) plane, while the conjugates’ samples showed anatase phase of TiO2 with (101) plane. The R-SWNTs and R-MWNTs dispersions revealed poor killing ability toward both Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). In contrast, the prepared SWNTs–TiO2/Ag and MWNTs–TiO2/Ag conjugates exhibited significant inhibitory effect against bacterial strains after 24 h of incubation. The cytotoxicity of these newly developed conjugates was assessed toward uterine cancer (SiHa) cell and normal (WRL68) cell lines. The SWNTs–TiO2/Ag and MWNTs–TiO2/Ag conjugates were able to selectively kill tumor cells (~ 60 to 40%), whereas less affecting normal cells (~ 10%).

In this study, raw single-walled carbon nanotubes (SWCNTs) and multiwalled carbon nanotubes (MWCNTs) were chemically treated with sulfuric acid (H2SO4) and nitric acid (HNO3) in a ratio (3:1). These carbon nanotubes (CNTs) have been coated with Ag-doped TiO2 nanoparticles (NPs) by using the sol–gel method. All samples have been studied by X-ray diffraction (XRD), Fourier transform-infrared (FTIR) spectroscopy, UV–vis spectroscopy, field-emission scanning electron microscopy (FESEM), energy-dispersive spectroscopy (EDS), and zeta potential analyzer. X-ray diffraction analysis revealed that the polycrystalline structure of silver (Ag) embedded with anatase titanium (TiO2) nanoparticles, while SWCNTs and MWCNTs were verified by EDS spectra due to covering of the (002) peak of carbon nanotubes (CNTs) by the (101) diffraction peak of the TiO2. The FTIR results confirmed the formation of oxygen functional groups onto the SWCNTs and MWCNTs. FESEM results indicated that TiO2/Ag nanoparticles (NPs) successfully loaded onto SWCNTs and MWCNTs. UV–vis absorbance results show a decrease in the energy band gap of MWCNTs-Ag/TiO2 and SWCNTs-Ag/TiO2 in comparison with pure TiO2. Antibacterial activities of nanocomposite samples against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were evaluated by an international recognized test (ASTM E2149). The results showed that nanocomposite samples have a strong bacterial inhibition against E. coli and S. aureus. Gram-negative bacteria appeared to be more resistant to nanocomposite materials than Gram-positive bacteria under illumination by UV light.

Recently, Organometallic trihalide perovskites have been commonly studied owing to their outstanding optoelectronic characteristics. The current study uses reduced graphene (rGO) into perovskite solution as harvester layer for efficient mesoscopic perovskite solar cells (PSCs). We systematically investigated the impact of rGO additive on the optoelectronic performance properties of PSCs. The perovskite film with the rGO exhibited a dense and pinhole-free film with good crystalline nature. While, the devices without the rGO additive suffered from severe recombination process, which was investigated with photoluminescence (PL) spectroscopy. Consequently, the device with the rGO exhibited a power conversion efficiency (PCE) of 11.55%, together with an open voltage (Voc) of 0.934 V, a short current density (Jsc) of 17.67 mA/cm2 and a fill-factor (FF) of 70%.

In this work, TiO2 nanofibers thin films were prepared by using different immersion times for hydrothermal method. Annealing in air at different temperatures of (400,500, and 600)°C at constant time (1 hour) were achieved for all films. Many analysis and measurement had been done (XRD, SEM, EDX, and AFM), and optical (UV-Visible spectroscopy, PL spectroscopy, and Spectral Response). The properties of nanofibers TiO2 films were investigated and analyzed for films. The SEM analysis of TiO2 films showed nanofibers shapes with diameter of about 21 nm. The absorption edges are located at UV-region, and the Eg has higher values compared with Eg for bulk TiO2 film. Spectral response measurements show photocurrent peaks for TiO2 nanotube films centered at UV-region (350 nm).

In this work a standoff Raman spectroscopy SRS system has been designed, assembled andtested for detecting explosives (Ammonium nitrate, Trinitrotoluene and Urea nitrate) in darklaboratory at 4 m target-telescope distance. The SRS system employs frequency doubled Nd:YAGlaser at 532 nm excitation with laser power of 250 mW and integration time of 2 second. The Cassegrain telescope was coupled to the Ventana Raman spectrometer using a fiber optics cable, and Notch filter is used to reject Rayleigh scattering light. The Raman scattered light is collected by a telescope and then transferred via fiber optic to spectrometer and finally directed into charge coupled device CCD detector. In order to test SRS system, it has been used to detect the Raman spectra of Toxic Industrial Compounds TIC such as acetone, toluene, and carbon tetrachloride. The SRS results were compared with conventional Raman microscopy results using a bench top Bruker SENTERRA Raman instrument.

In this work, TiO2 nanostructure thin films were deposited by using anodization technique, while CdS thin films were deposited on TiO2 films by two methods chemical bath deposition (CBD) and successive ionic layer adsorption and reaction (SILAR). The structure of TiO2/CdS films were investigated and analyzed by XRD, SEM, and AFM, but the optical properties were investigated by UV–visible spectroscopy, PL spectroscopy, and spectral response. XRD analysis of all deposited films has confirmed the formation of two phases one is tetragonal phase (anatase, and rutile) for TiO2, and second hexagonal phase which belong to CdS layer. SEM images of TiO2 nanotubes arrays (NTAs)/CdS showed the TiO2 NTs walls become decorated with aggregates of fine CdS nanoparticles that partly penetrate into the TiO2 NTAs pores. AFM measurements displayed increase in the surface roughness compared with TiO2 films. PL measurement results of TiO2/CdS core–shell show two peaks, one is located at UV-region pointed to energy band gap for TiO2 nano films, and second one is located at visible region pointing to recombination of photogenerated electron–hole pairs within CdS layers. Spectral response measurements showed photocurrent peaks for all TiO2/CdS films deposited with different electrolyte solution have red-shift to visible region. When illuminated with a UV–Vis light source, the TiO2/CdS core–shell films displayed high response. A higher response to UV–Vis light was attained with the use of TiO2 NTAs/CdS films prepared by anodization /CBD. This approach offers a technique for fabricating photoelectrodes.

The raw-SWNTs and raw-MWNTs were chemically oxidized with a mixture of sulfuric acid and nitric acid under ultrasonic vibration. The functionalized-SWNTs (F-SWNTs) and functionalized-MWNTs (F-MWNTs) were characterized by using ultra violet-visible spectrophotometer, X-ray diffraction, and field emission scanning electron microscopy (FESEM). The antibacterial efficiency of SWNTs and MWNTs towards Escherichia coli (E. coli) as gram-negative bacteria was evaluated via viable count method and fluorescence microscopy. The results of viable count method showed that the SWNTs and MWNTs have higher inhibitory effect after being treated with H2SO4/HNO3.The E. coli images under fluorescence microscopy exhibited that almost red color for dead cells, which confirms the efficient lethal ability of F-SWNTs and F-MWNTs.

Background: Seizures are known sequelae of stroke but the national estimates of seizure related hospitalization in post stroke period are not known. Objective: To determine the rates and independent predictors of seizure related hospitalization among patients admitted to hospital with intracerebral hemorrhage (ICH), subarachnoid hemorrhage (SAH) and ischemic stroke (IS). Methods: The study population included patients in the 2013 Nationwide Readmissions Database (NRD) over the age of 18 years with a principal diagnosis of SAH (ICD9 = 430xx), ICH (ICD9 = 431xx) and IS (ICD9 = 433x1 & 434x1). Subjects with a secondary diagnosis of arterio-venous malformation, brain tumor, or traumatic brain injury were excluded. Seizures were defined by ICD9 codes (345.0x-345.5x, 345.7x-345.9x,780.39). Cox proportional hazards analysis was used to assess the relative risk of rate of readmission with seizure for patients in the presence of selected comorbidities and potential confounders such as age, sex, and type of stroke. Results: A total of 557,033 subjects met all eligibility criteria, of which 497,138, (89.3%) were admitted with IS; 43579(7.8%) with ICH and 16316(2.9%) with SAH. The overall estimated 1 year Kaplan Meir seizure free rate (±SE) was 98.99; it was 99.14% and 99.46% in patients with ICH, SAH and IS respectively. After adjustment for potential confounders, independent predictors of re-admission with seizure within 1 year included female gender (odds ratio, 1.14, 95% confidence interval (CI) 1.02-1.27), age≤60 (OR = 1.26, 95 % CI 1.12-1.41),hemorrhagic stroke (ICH/SAH) (OR =1.18;95 % CI 1.02-1.35), seizure during hospitalization (OR = 7.51, 95 % CI 6.70-8.43 and sodium abnormalities during the hospitalization (OR = 1.43, 95 % CI 1.21-1.69). Conclusion: Rate readmission of seizure after stroke within first year is low and there may be residual confounding by severity. Our findings do not support a need for routine prophylactic anti-epileptic drug use after stroke.

In order to promote the biological applications of graphene based materials, great exploration for nano-scale preparation of graphene oxide (GO) has been made with a novel facile processing method and low cost. For these reasons this method has been carried out in the following study. The GO nanosheets have been prepared depending on Hummer’s method, which represents an easy and efficient technique since 1958. Alternations have been done to simplify this method in order to prepare the GO with a novel way without a need to add NaNO3. Also this preparation has been achieved at room temperature without a need to water bath at temperatures of 35 °C and 98 °C. Structural and morphological properties and contents of the synthesis nanosheets were characterized by using XRD, SEM, and EDS techniques, respectively. The purpose of this work is to evaluate the antibacterial activity of GO nansheets against Gram-negative and Gram-positive bacteria of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), respectively. Bacteriological test were achieved by colony forming units (CFUs) assay. CFUs assay has ensured potential of GO as an anti-infective agent for controlling the growth of two spices of bacteria. The results have showed that Gram-positive were more effective by nanosheets than Gram-negative.

In this work, single wall nanotubes (SWNTs) and multi wall nanotubes (MWNTs) have been chemically treated with sulfuric acid and nitric acid (3:1 v/v). The Ag-doped ZnO and Au-doped ZnO nanoparticles have been decorated on SWNTs and MWNTs by the chemical precipitation method. The hybrid materials have been characterized via x-ray diffraction (XRD), ultraviolet-visible (UV-vis) spectrophotometer, energy dispersive spectroscopy (EDS), and electron microscopy (FESEM, TEM). Antimicrobial activity of hybrid materials has been evaluated by using colony-forming unit assay and fluorescence microscope. Escherichia coli (E. coli) as Gram-negative and Staphylococcus aureus (S. aureus) as Gram-positive have been employed as the target bacterium. All hybrid materials have been reported to possess strong antimicrobial activity towards E. coli and S. aureus bacteria, due to synergistic effect between metal-doped ZnO nanoparticles and carbon nanotubes. A high bactericidal rates have been reported for all hybrid materials incubated in the dark and under UV light. The photocatalytic properties of metal-doped ZnO have been played important role for inhibiting bacterial growth due to generate reactive oxygen species (ROS) causing cellular toxicity.

In this work, TiO2 nanotube thin films were prepared by using the anodization technique. Different electrolytes solutions were used to specify the optimum condition. Annealing in air at different temperatures of (400, 500, and 600)[Formula: see text]C at constant time of 1[Formula: see text]h was achieved for all films. The structure (XRD, SEM, EDX, and AFM), and optical (UV–Visible spectroscopy, PL spectroscopy, and Spectral Response) properties of nanotube TiO2 films were investigated and analyzed for different electrolyte solutions. XRD analysis of all deposited films has confirmed the formation of polycrystalline-tetragonal phase (anatase, and rutile) with increase in crystalline size and, annealing temperatures. SEM measurements of TiO2 films show nanotube shapes with outer diameter of (80–130) nm. EDX analysis confirmed the stoichiometry ratio between Ti and O to be 1:2 to produce TiO2 film. PL measurement results show two peaks: one located at UV-region pointing to energy band gap (Eg) for TiO2 nano films; the second one is located at visible region pointing to impurities on films. Spectral response measurements show photocurrent peaks centered at UV-region (355[Formula: see text]nm). Then, TiO2 films were deposited with different electrolyte solution for photoelectrocatalytic (PEC) application. The higher response to UV-light was received by using TiO2 film grown by anodization technique with (HNO[Formula: see text][Formula: see text]HF) electrolyte solution.

In this paper, the functionalization of raw-MWCNTs involves oxidation reaction using concentrated acid mixture of HNO3:H2SO4 (1:3), via ultrasonic bath (170 W, 50 kHz) to obtain functional groups. Then Ag nanoparticles are decorated the outside over the surface of functionalized MWCNTs using a chemical reduction process resulting in the formation of(Ag/ MWCNTs) hybrid material. The results showed that outer diameter functionalized F-MWCNTs andAg nanoparticles size was about (11-80) nm and (10 to 25) nm, respectively using TEM and HRTEM. The crystallographic structure of MWCNTs using X-ray diffraction (XRD) analysis proved diffraction peaks at 38.1°, 44.3°, 64.7° and 77.4° degrees namely, Ag (111), Ag (200), Ag (220), and Ag (311) of the face-centered cubic lattice of Ag, respectively, excepting the peak at 2θ =25.6°, which correspond to the (0 0 2) reflection of the MWNTs are corresponding to Ag/MWNTs. The antimicrobial activities of Ag/MWCNTs hybrid using plate count method showed that decreasing a large...

Detalled Raman spectra of the NO−3 ion substitutionally isolated in Rbl, Kl and KCl have been investigated at various temperatures between 77 and 300 K. These spectra, together with their corresponding infrared spectra, have been used to study the effective symmetry of these systems. Changes in the infrared and Raman activities of some of the modes of the NO−3 ions have been observed as the samples were cooled. Two different symmetries, one at room and the other at low temperature, have been identified as D3 and C3v respectively.

Raman and lattice side band spectra of the external modes of ReO−4, NO−3 and NCO− isolated wuthin KI have been recorded at 300K and 77K. Similarities and differences shown by these spectra are interpreted in terms of (i) highly specific properties of the impurity-occupied lattice site (eg. torsional and translational oscillations of the impurity ion), (ii) a very general but weak activation of host lattice modes due to the disorder imposed by the randomly distributed impurity ions and (iii) selective enhancement of specific host lattice modes which, as a result of having the same symmetry properties, can resonate with (and draw intensity from) the modes described in (i) above. It is in order to investigate this third point, (which has been totally ignored in previous work on the external mode spectra of polyatomic impurity ions) that three ions with different symmetries have been used.

The Raman spectra of twelve different alkali halide/NCO− systems have been investigated, and these spectra have been compared with the previously-studied infrared spectra. In the external mode region there are significant differences in the infrared and Raman spectra associated with the in-band features.

The vibrational spectra of the NO − 3 ion isolated within RbCl, RbBr and RbI has been investigated at various temperatures between 77 and 300 K, by means of i.r. and Raman techniques. At room temperature, the i.r. and Raman activities of the NO − 3 internal modes suggest that the NO − 3 -occupied sites have D 3 symmetry. However at low temperature C 3ν symmetry is suggested. One localized mode has been observed for each system, close to the top of the optic branch of each lattice. They appear at 119, 145 and 166 cm −1 for RbI, RbBr and RbCl respectively. In addition, one gap mode (low density of state mode), centred at 111 cm − , has been observed in the uncertain “gap” region between the acoustic and the optic branches of the lattice vibrations of RbCl.

The SbF − 6 ion is found to lose its O h symmetry when isolated within RbI and RbBr lattices. The most likely symmetry is D 2h . ν 3 (F 1u ) and ν 4 (F 1u ) each split into three infrared active components. Two components are observed in the infrared from the previously inactive ν 6 (F 2u under O h ) but no infrared absorption has been observed for those modes which were Raman active under O h symmetry.

Raman spectra showing features associated with the internal and external modes of vibration of the NO3- ion isolated within a KI crystal have been recorded for a sample temperature of 80K under hydrostatic pressures of up to 5 kbar. Over this pressure range the frequencies of all the observed modes appear to increase linearly with the applied pressure at rates between 0.4 and 1.05 cm-1 kbar-1. Contrary to the conclusion reached in a recent paper by Khatri and Verma (1982) it is shown that the volume dependence of the frequency of the 72.3 cm-1 gap mode is the dominant effect in the temperature dependence of this frequency.

Single crystals of KCl, KBr, KI and RbI doped with up to about 0.1% ReO4- have been grown and studied by infrared and Raman methods. The spectra indicate that contrary to the implications of Zaporozhets and Pasechnyi (1979), the isolated perrhenate ion possesses Td symmetry in all cases.

Multiwalled carbon nanotubes (MWCNTs) have a great potential in wide applications however faces limitation in terms of dispersion feasibility. This work examines the functionalization process of MWCNTs that is treated with various reagents (nitric acid, 65%HNO3 and followed by treatment with hydrogen peroxide, 30% H2O2 as reduction reagent) and (oil olive) via ultrasonication technique and comparison between their results in an attempt to achieve experimental conditions which efficiently functionalize the surface of multiwalled carbon nanotubes (MWNTs) which minimizing nanotube damage. The results were then confirmed by Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), and Scanning Electron Microscopy (SEM). FTIR spectrum shows the existence of carboxyl group after treatment with (Acidic oxidation and oil olive) and indicates the functionalization of MWCNTs on the outer surface wall .SEM micrographs show the occurrence of surface modification on the MWCNTs structure after each treatment. Finally, a well dispersed of MWCNTs colloidal was successfully obtained with less MWCNTs structure collapsed.