Monthly Archives: October 2017

br Method br Results and

Method

Results and discussion

Conclusion
The synthesis of 1,3-diazole derivatives was performed both under ultrasound (US) irradiation and under conventional thermal heating (TH). N-alkylation of the imidazole under US gives slightly higher yields. In addition, the amount of solvent needed was about two times less compared with conventional TH, whereas the reaction times reduce from hours or even days to minutes. Taking into consideration these advantages the N-alkylation methods could be considered environmentally friendly. Overall, the use of US proved to be more efficient than TH, the efficiency of the former in the N-alkylation reaction of 1,3-diazole being assigned to cavitation effects. The different behavior of imidazole and benzimidazole in the N1-alkylation reactions under US irradiation should relate to the different acidity of the hydrogen haspin inhibitor from the 1-st nitrogen in the two heterocycles and also to their different solubilities. Some of the melting points of the synthesized imidazolium salts being lower than 30°C encourage us to claim that these compounds could be considered ionic liquids.

Introduction
Cavitation erosion is a process that affects a significant number of components used in hydraulic equipments, like pumps, ship propellers or turbines for hydroelectric power plants [1]. When subjected to cavitation erosion, materials behave differently, depending on their composition, structure, surface treatments etc [2]. During the cavitation erosion of metals and alloys, the work-hardening process due to the bubble collapse in the superficial layer is associated with a surface hardness increase [3]. For ductile materials it was also observed that the erosion rate is scaled by the ratio of the thickness of the hardened layers to the covering time, but also depending on the flow aggressiveness [4]. Franc and Michel [1] also pointed out that fatigue mechanisms have to be expected due to the repetitive nature of the process, involving high strain rates and short impact duration.
In order to asses one material’s resistance to such conditions, specific tests are standardized, aiming to simulate the cavitation erosion process in accelerated conditions performed in a laboratory. However, there is significant difference compared to real cavitation phenomena that occur in components of hydraulic machines and there are concerns on accepting the accelerated erosion tests versus the full scale erosion. Choi et al. [5] studied the influence of different erosion intensities and testing methods and concluded that the relative ranking of erosion resistance of some materials depends on the cavitation intensity. According to Chahine et al. [6], the ultrasonic method leads to the formation of a cavitation bubble cloud, always at the same location, with bubbles of nearly uniform size and form obtained at a fixed frequency, compared to the real cases where a distribution of nuclei size exists as well as various exciting frequencies. They also emphasized that the standardized test does not allow a full characterization of the behavior in real conditions due to the absence of a real liquid flow or the interaction of bubble nuclei with turbulent vortex filaments.
Compared to real cavitation erosion that occurs after a long duration of exposure, the standardized accelerated tests provide however relevant laboratory results that can be used to compare materials tested under similar conditions. The equipment for this purpose leads an intensive erosion process in a controllable and reproducible manner, by generating bubbles clouds that erode the surface of a sample made out of the tested material. Such equipments can be used to assess the resistance to cavitation erosion of a material in terms of the erosion rate, thus allowing materials to be classified based on this property. Ultrasonic equipments have been developed for the purpose of evaluating the cavitation erosion process, according to ASTM G32-09 standards [7,8]. They have the advantage of using simple equipments, with easily controllable parameters, that generate longitudinal vibrations, amplified and transmitted into the liquid as ultrasonic waves. The bubbles that form during these vibrations implode at the surface of the samples leading to a cumulative effect that has a destructive effect on the surface with an energy that depends on the parameters used in the process and the characteristics of the ultrasonic probe. The cavitation erosion pits depend on the material’s particularities with the predominant failure related to the fatigue process [9]. Although the ultrasonic cavitation erosion experiments can be performed in various fluids more intense cavitation occurs for higher surface tension of the fluid. The increase of the viscosity is expected to lead to a reduced erosion of the surface due to the decrease in the rate of growth and collapse of the bubbles [10].

Most of the studies in application of heterogeneous

Most of the studies in application of heterogeneous iron sources in sono-Fenton process were focused on Fe2O3 and Fe3O4 particles [16–19]. But in this work, γ-FeOOH nanoparticles was synthesized and used as heterogeneous catalyst in sono-Fenton process for treatment of textile wastewater contains reactive orange 29 (RO29) as an azo dyestuff. To evaluate ability of this catalyst in sono-Fenton process the effect of γ-FeOOH dosage, H2O2 concentration, ultrasonic power and initial solution pH was investigated. Oxidative ability of H2O2 in decolorization of the wastewater was compared with that of other oxidative agents. Degradation of RO29 molecules and mineralization of the textile wastewater were followed by Gas chromatography–mass spectrometry (GC–MS) and chemical oxygen demand (COD) analyses.

Experimental procedure

Results and discussion

Conclusions
Results of this work indicate that γ-FeOOH nanoparticle is an appropriate catalyst to use in sono-Fenton process for treatment of wastewater contains organic pollutants. The catalytic performance of γ-FeOOH was dependent on its dosage, H2O2 concentration, pH and ultrasonic power. This catalyst has a potential to use in successive decolorization processes. H2O2 is appropriate oxidant to use in US/γ-FeOOH/oxidant process. The RO29 was effectively degraded to small CA-074 Me and then mineralized by US/γ-FeOOH/H2O2 process.

Acknowledgments
The authors thank the University of Tabriz (Iran) and Province Industries and Mines Organization of East Azarbaijan for all of the support provided.

Introduction
Ultrasound has been used in medicine for diagnostic imaging applications, facilitating the delivery of drugs, promoting wound healing as well as directly tumor ablations [1,2]. Ultrasound induces cell-damage through mechanical forces (i.e., microstreaming, shear stress and bubble-cell collisions) and chemical toxins (i.e., free radicals and peroxides) [3,4]. The mechanical and chemical damages caused by ultrasound depend strongly on the ultrasound frequency and intensity, because various types of cavitation bubbles occur under different sonication conditions that determine the types of damage [3]. Two types of cavitation bubbles have been categorized to aid in understanding the biological effects of ultrasound, non-inertial and inertial [4]. Non-inertial cavitation bubbles are defined as microbubbles that oscillate around an equilibrium radius without undergoing violent collapse. Inertial cavitation bubbles are defined as bubbles that are nucleated in solution and undergo violent collapse, that produce localized high temperatures and pressures. Based on the literature, both types of cavitation could be responsible for cell death via a mechanical pathway, while only the inertial cavitation could result in sonochemically induced cell death [5,6].
The presence of certain drugs in sonication conditions could greatly enhance cell death. Studies showed that these effects occur not via increasing the cellular susceptibility to the sonomechanical forces but rather due to the sonochemical reactions [7–9]. These synergistic effects of drugs, which are also known as sonosensitizers, and ultrasound are termed as sonodynamic therapy (SDT). Porphyrins or porphyrin-like compounds, such as protoporphyrin IX (PpIX), are the agents of choice in most SDT experiments because they have specific accumulation in diseased tissues, such as tumors [10]. PpIX could significantly enhance the cell damaging effects of ultrasonic exposure on different cancer cell lines in vitro[11]. In addition, pretreatment of cells with antioxidant agents such as N-acetylcysteine (NAC), cysteamine, mannitol and catalase, greatly reduce the occurrence of cell death [10,12,13]. These prior studies indicate that the sonochemical activation of PpIX and the subsequent production of reactive oxygen species (ROS) may play a pivotal role in SDT-induced cell death. However, the exact mechanism involved in the sonochemical effects is still not clear.

Most of the studies in application of heterogeneous

Most of the studies in application of heterogeneous iron sources in sono-Fenton process were focused on Fe2O3 and Fe3O4 particles [16–19]. But in this work, γ-FeOOH nanoparticles was synthesized and used as heterogeneous catalyst in sono-Fenton process for treatment of textile wastewater contains reactive orange 29 (RO29) as an azo dyestuff. To evaluate ability of this catalyst in sono-Fenton process the effect of γ-FeOOH dosage, H2O2 concentration, ultrasonic power and initial solution pH was investigated. Oxidative ability of H2O2 in decolorization of the wastewater was compared with that of other oxidative agents. Degradation of RO29 molecules and mineralization of the textile wastewater were followed by Gas chromatography–mass spectrometry (GC–MS) and chemical oxygen demand (COD) analyses.

Experimental procedure

Results and discussion

Conclusions
Results of this work indicate that γ-FeOOH nanoparticle is an appropriate catalyst to use in sono-Fenton process for treatment of wastewater contains organic pollutants. The catalytic performance of γ-FeOOH was dependent on its dosage, H2O2 concentration, pH and ultrasonic power. This catalyst has a potential to use in successive decolorization processes. H2O2 is appropriate oxidant to use in US/γ-FeOOH/oxidant process. The RO29 was effectively degraded to small ccr5 antagonist and then mineralized by US/γ-FeOOH/H2O2 process.

Acknowledgments
The authors thank the University of Tabriz (Iran) and Province Industries and Mines Organization of East Azarbaijan for all of the support provided.

Introduction
Ultrasound has been used in medicine for diagnostic imaging applications, facilitating the delivery of drugs, promoting wound healing as well as directly tumor ablations [1,2]. Ultrasound induces cell-damage through mechanical forces (i.e., microstreaming, shear stress and bubble-cell collisions) and chemical toxins (i.e., free radicals and peroxides) [3,4]. The mechanical and chemical damages caused by ultrasound depend strongly on the ultrasound frequency and intensity, because various types of cavitation bubbles occur under different sonication conditions that determine the types of damage [3]. Two types of cavitation bubbles have been categorized to aid in understanding the biological effects of ultrasound, non-inertial and inertial [4]. Non-inertial cavitation bubbles are defined as microbubbles that oscillate around an equilibrium radius without undergoing violent collapse. Inertial cavitation bubbles are defined as bubbles that are nucleated in solution and undergo violent collapse, that produce localized high temperatures and pressures. Based on the literature, both types of cavitation could be responsible for cell death via a mechanical pathway, while only the inertial cavitation could result in sonochemically induced cell death [5,6].
The presence of certain drugs in sonication conditions could greatly enhance cell death. Studies showed that these effects occur not via increasing the cellular susceptibility to the sonomechanical forces but rather due to the sonochemical reactions [7–9]. These synergistic effects of drugs, which are also known as sonosensitizers, and ultrasound are termed as sonodynamic therapy (SDT). Porphyrins or porphyrin-like compounds, such as protoporphyrin IX (PpIX), are the agents of choice in most SDT experiments because they have specific accumulation in diseased tissues, such as tumors [10]. PpIX could significantly enhance the cell damaging effects of ultrasonic exposure on different cancer cell lines in vitro[11]. In addition, pretreatment of cells with antioxidant agents such as N-acetylcysteine (NAC), cysteamine, mannitol and catalase, greatly reduce the occurrence of cell death [10,12,13]. These prior studies indicate that the sonochemical activation of PpIX and the subsequent production of reactive oxygen species (ROS) may play a pivotal role in SDT-induced cell death. However, the exact mechanism involved in the sonochemical effects is still not clear.

Recent advances in nanostructured composite materials have been led

Recent advances in nanostructured composite materials have been led by the development of new synthetic methods, and the sonochemical one [12] has been proven to be a useful tool for generating novel materials [13]. In this THZ1 Hydrochloride sense, sonochemistry can be a new, economical and green method for the synthesis and decoration of metallic particles on various ceramic substrates. Ultrasonic irradiation can act on shape and size of the inorganic metal nanoparticles, thanks to the extreme conditions attained during bubble collapse, have been exploited to produce nanoscale metals, metal oxides, and nanocomposites [14]. The first report on the use of ultrasound for fabrication of noble metals was in 1987 by Gutierrez et al. [15], while for this work the experimental procedure is based on to the work of Tao et al. [16].
Starting from the very promising possibilities to use US to obtain metal nanoparticles and substrates decoration as well, sonochemistry represents a novel and interesting way to decorate the surface decoration of TiO2 substrates with M-NPs and MO, in our case copper for all the reasons mentioned above.
We proposed this method to decorate a commercial substrate of TiO2 in a previous work [17]. In that case, we wanted to prove the efficiency of the sonochemical route for TiO2 decoration with different metals, choosing as most interesting molybdenum, rhenium, tungsten and copper. TiO2 decorated with copper didn’t show good results in term of photocatalytic activity. However, several publications about the very good and promising properties of copper nanoparticles to modify TiO2, enhancing its photoactivity, in particular under solar and visible light, have been published in the recent years [18,19]. For this reason, we investigate here the influence of copper loading on the photocatalytic activity of TiO2 catalysts. In addition, the distribution and morphology of metal and metal-oxides NPs on the TiO2 surface are studied for different amount of metal precursor used during the synthesis procedure.
As in the work mentioned above, the TiO2 substrate employed in the present contribution is commercial and micro-sized. Although TiO2-nanopowders exhibit the best performances, a micro-sized support is not dangerous for health, easier to handle, and more suitable for a surface decoration [20].
Samples of Cu-metal and metal-oxides decorated titania, prepared using high energy US, were synthesized, considering copper amounts in the range 1–75wt.%. Moreover, because of (i) the very few studies on the photocatalytic performance of Cu NPs in respect to his quantity and (ii) the need to find photocatalytic materials able to work under visible light, some tests on their photoactivity for the abatement of VOCs molecules in the gas phase were performed, investigating both the impact of the copper amount and the importance of the power of the irradiation. Photocatalytic activity of TiO2-based materials were tested though the degradation of acetone and acetaldehyde.
Acetone is one of the most common indoor air pollutants and its photocatalytic degradation has been extensively studied. For this reason, it is suitable to study the efficiency of different types of TiO2[21,22]. Different mechanisms can contribute to the overall acetone photo-oxidation reaction, and in all of them acetaldehyde is formed as by-product [23]. Moreover, both acetone and acetaldehyde are hydrophilic and polar pollutants that usually are present and ubiquitous in indoor environments.

Materials and methods
TiO2 (1077 by Kronos) is a commercial and micro-sized sample produced by Kronos® company. It consists of pure anatase having an average particles size of ∼110nm; the surface area is 12m2g−1 and it has a band gap of 3.2eV. The precursor compound for copper is CuCl2·2H2O (⩾99% Sigma Aldrich), which was purchased and used without further purification, as all the other reagents used for the preparation described below. The investigation on the photoactivity performance of each sample was performed using acetaldehyde (ACS Reagent, ⩾99.5% Sigma–Aldrich) or acetone (Chromasolv plus, for HPLC, ⩾99.9% Sigma–Aldrich) as reference pollutant molecules.

Dyes present in water system without preliminary treatment as

Dyes present in water system without preliminary treatment as a non-legal and desirable phenomena make an urgent requirement to supply efficient low coast and ecofriendly protocol for removal of pollutants from water resource to promote the quality of water following reducing pollutants and level to value lower than threshold limit [3–5].
The conventional treatment methods like ion-exchange, electro dialysis, micro- and ultra-filtration, reverse osmosis, oxidation, and solvent extraction are expensive and tedious with respect to adsorption [6–9]. The latter protocol is very favorable method based on its simple, easy operation and high-performance efficiency operations is strongly recommended to remove toxic substances. Carbon based adsorbent because of presence of various functional group oppress structure is highly demand material which capable adsorption process for efficient quantitative and safe removal of water polluted media. [10–12].
Activated carbon (AC) as best and high abundant support has high demand and application for removal of organic contaminants to regulate environmental quality [13–15].
Modification of AC surface via nano scale materials simultaneously led to appearance of more extra reactive center (metallic or nonmetallic) which in combination to the enhancement of surface area and porosity which in cooperation with AC functional group strongly led to progress in chemisorption and/or physisorption of various compounds. The size, surface structure and intraparticle interaction of nanomaterials enhance their usability to interact with other compounds [16–18].
Combination of above mention advantages with ultrasound application which accelerate mass transfer via raising pannexin-1 inhibitor coefficient by best dispersion of adsorbent and also probability via opening the porosity of adsorbent lead to remarkable enhance in efficiency of adsorption procedure [19,20]. Roosta and coworkers [21] pointed out the enhancement of adsorption rate of dyes onto ZnS:Ni nanoparticles loaded on AC. Our recent research reveal that sonication lead to raising mass transfer coefficient through cavitation and acoustic streaming to increase dyes removal [22].
Present study focus on simultaneous adsorption of MG and MB by ZnS: Mn-NPs-AC under ultrasound while central composite design (CCD) combined with RSM using minimum number of experiments permit to achieved useful information about interaction in main effect of variables like [23,24]. pH, sonication time, adsorbent mass and MG and MB concentration on the adsorption process to search and fine best operation optimum conditions. Also, the effect of nanoparticles pannexin-1 inhibitor content on dyes adsorption process was investigated and the kinetic and isotherm of adsorption were studied.

Experimental

Results and discussion

Conclusion
A multi-response optimization study based on CCD allow searching optimum conditions to achieve the best and maximum MG and MB adsorption onto ZnS: Mn-NPs-AC by the aid of ultrasound. Combination of RSM with CCD guide us that sonication, adsorbent mass and pH have significant effect on dyes adsorption. Values of “Prob>F” less than 0.0001 indicate model terms have significant effect on adsorption of MG and MB. Maximum simultaneous dyes removal (>98.50) was obtained at pH 7.0, 0.025g adsorbent mass, 15mgL−1 of MB and MG at 3min sonication. The Pareto chart results enunciated that the significance of the parameters is as follows (the most to the least significant): sonication time>adsorbent mass>pH>initial dye concentrations. Adsorption kinetics including the pseudo-first and second order kinetic models were researched and the data fitted better with the pseudo-second order kinetic model (R2=0.997). For adsorption isotherms, Langmuir isotherm was proved to be the best correlation (R2=0.997) compared with the Freundlich isotherms. The mechanism of under study dyes adsorption under ultrasound assisted irradiation show and proof great potential application of sonication for treatment of dyes.

Ibuprofen IBP with the chemical name methylpropyl phenyl propanoic acid

Ibuprofen (IBP), with the chemical name, 2-[3-(2-methylpropyl)phenyl] propanoic purchase AZD4547 is a nonsteroidal antiinflammatory drug (NSAID) and has been identified recently for posing high risk to human health, especially to sensitive populations such as children, pregnant women and fetus [1]. Since its availability as an over-the-counter preparation in 1984, the American Association of Poison Control Centers’ National Data System has released a report on IBP’s accountability for almost 70,000 exposures in children and adolescents annually, with greater exposure to less than six years of age [2,3]. If IBP inhibits cyclooxygenase enzyme, the ultimate transformation of arachidonic acid to prostaglandins, prostacyclin, and thromboxanes will be impeded [4]. Adding to the risk, 80% of IBP has been detected in the surface water of Korea [5] with a mean average of 0.30 lgL−1 in plant wastewater influents [6]. Hence, urgent development of a systematic and comprehensive degradation methodology of IBP from aquatic environments is a must. Generally, conventional technology has shown incomplete removal of pharmaceutical products in drinking water, which has lead to adoption of more efficient and advanced technologies [7]. On the other hand, advanced oxidation processes (AOPs) has gain strong positive recognition in the field of wastewater treatment due to its environmental friendly approach with the main target to generate clean and highly reactive hydroxyl radicals (high oxidation potential of 2.80V) which can degrade all types of pollutants, nonspecifically [8]. However, the application of individual AOPs has been reported to be expensive, and generally exhibits lower energy efficiencies as an effective wastewater treatment procedure [9]. Many researchers have proved the combination of ultrasound and electrochemistry (US/EC) as one of the most effective technologies for pollutant degradation [10]. Though the hybrid technology is credited for many studies, the oxidation of Ibuprofen using US/EC has been reported first by our group. One of the justifiable reasons for the adoption of hybrid US/EC is that both the processes can be carried out simultaneously in one reactor, with the same operating cost; more specifically, with the reduction in energy consumption (as per our previous experimental data). One more remarkable feature is that the system can be operated without utilizing harmful reagents. Besides, from mechanistic point of view, both can be hybridized on a same platform [11]. Three distinct mechanisms correlating US and EC that can give rise to the potential synergy for the degradation of pollutants are: a) Electrode cleaning by US: Cavitation effects of US such as microjet have beneficial impact on the electrodes by cleaning and decreasing the diffusion layer thickness to less than 1μm [12,13]. The direct application of US to an electrode surface enhances the performance by cleaning it [14,15] and thus extensively increasing the degradation of toxic compounds [16–18]. b) Enhancement of mass and electron transfer by US: Activating the electrode surfaces by microjet formation arising out of cavity collapse also enhances mass and electron transfers, thereby increasing the contact of pollutant with reactive radicals. The EC current is also reported to have increased more than 10 times [19]. c) Cavitation bubble formation at electrode: As cohesive force for bubble formation is lower at water-solid interface than water-water, electrodes provide a surface which can act as potential nucleation sites [20]. However, both the processes are still energy intensive, making the issue of high energy consumption to persist. One typical approach for the enhancement in energy efficiency and lower energy consumption is the application of catalyst. The use of appropriate catalyst reduces the energy consumption, at the same time increases the pollutant degradation efficiency. Many researchers have applied various types of material to cavitation system, however, catalyst that has been synthesized for the combined US/EC are still countable. A review on the application of catalyst on US/EC system has been done in Table 1. Yasman et al. developed finely divided (black) Pd and Pd–Fe powder for sono-electro-catalytic reduction of chlorophenoxy herbicides (2,4-D) and chlorophenols (2,4-DCP) in aqueous solutions, which can be accounted as the first proper application of catalyst on US/EC technique for pollutant degradation [21]. However, no strategy to recover the catalyst was mentioned. Recently, Yang et al. and Shestakova et al. also developed novel US/EC catalysts, but in the form of nanocoated electrodes. Hence, if impregnable adhesive is not used, it is also highly prone to detaching off due to the strong microjet force of US on electrodes [22,23]. Besides, the benefit of increasing cavitation event, mainly in the bulk will also be reduced. Hence, a new and better kind of catalyst has been proposed in this present work, considering the prevailing mechanisms of the system. Electrolysis of water produces O2 and H+ on the anode (Eq. (1)), while H2 and OH− at the cathode (Eq. (2)). Recently, successful works have been reported for the direct synthesis of H2O2 with H2 and O2 on the surface of noble metals such as Pd, Au, Pt and Ag at ambient temperature [24,25]. Among them, Pd has been reported to show comparatively high activity with 85% selectivity and 14% conversion [26]. Besides, it is known to provide an ideal surface to dissociate H2 into two H atoms with no or insignificant energy barrier. The condition of adsorbed O2 without dissociating it can also be found in Pd’s case, which is another favorable criterion for H2O2 formation (Eq. (3)) [27].

There are a number of methods for determining and quantifying

There are a number of methods for determining and quantifying cavitation [4]. Sazgarnia et al. have studied the cavitation potential via two methods of sonoluminescence detection and terephthalic MLN 8237 cost (TA) chemical dosimetry at therapeutic intensities of ultrasound [5].
Acoustic cavitation generates free radicals from the breakdown of water and other molecules. When water is sonicated, OH radicals are formed on thermolysis of H2O. The initial step in the decomposition of water is the production of hydroxyl and hydrogen radicals. Simplified equations for production of free radicals by collapse of cavitation in water solutions are previously described by Sazgarnia and Shanei [6].
Such chemical products also may be used to measure cavitation activity. It has been shown that terephthalic acid (TA) [benzene-1, 4-dicarboxylic acid] is suitable for detecting and quantifying free hydroxyl radicals generated by the collapse of cavitation bubbles in ultrasound irradiations. During this process, TA solution as a dosimetric solution reacts with a hydroxyl radical generated through water sonolysis. Therefore, 2-hydroxyterephthalic acid is produced that can be detected using fluorescence spectroscopy with an excitation and emission wavelengths of 310 and 425nm, respectively [7,8].
Cavitation phenomenon could be facilitated by cavitation nuclei such as gas trapped in solid particles in the medium or in crevices in the walls of a vessel containing the irradiated liquid [9].
On the basis of a few reports, the existence of a particle in a liquid provides a nucleation site for cavitation bubble because of its surface roughness leads to decreased threshold intensity of the cavitation, and is also responsible for increasing the quantity of bubbles when the liquid is irradiated by ultrasound [10,11].
Gold nanoparticles (GNPs) have been characterized as novel nanomaterials for use in cancer therapy because of their special optical properties [12,13]. Their low toxicity, good uptake by mammalian cells, and antiangiogenetic properties make GNPs highly attractive for medical applications [14].

Materials and methods

Results
Hydroxyl radical production was measured in different TA solutions: TA solutions containing 15, 20, 28 and 35nm GNPs sizes and TA solution without GNPs in the field of 1MHz ultrasound waves at 0.5, 1 and 2W/cm2 intensities by the TA dosimetry method (excitation wavelength=310nm, emission peak wavelength=420nm, emission and excitation band width=5nm).
An example of the fluorescence emission spectrum in TA solutions containing 15, 20, 28 and 35nm sizes GNPs and with 60mg amount following 1MHz ultrasonic irradiation with 2W/cm2 intensity in continuous mode is presented in Fig. 1.
As shown in Fig. 1, the highest fluorescence signals were recorded in the TA solutions containing 35, 28, 20 and 15nm GNPs, respectively.
Fig. 2 shows the particle-amount dependence of the fluorescence signal intensity in the TA solutions with GNPs to that of a solution without GNPs with 2W/cm2 intensity in continuous mode. For Overwinding of DNA case, the size of GNPs was fixed to 35nm.
As can be seen in Fig. 2, the recorded fluorescence signal intensity increased at higher amount of GNPs up to 60mg. When the added amount of GNPs increased more than 60mg, however, the recorded fluorescence signal intensity became lower.
On the basis of our results, a significant difference in the recorded fluorescence signal intensity between TA solutions containing 35nm GNPs in the different amounts of GNPs and the TA solution without GNPs with 2W/cm2 intensity was observed (P<0.05). Fig. 3 shows the particle-size dependence of the fluorescence signal intensity in the TA solutions with GNPs to that of a solution without GNPs with 2W/cm2 intensity in continuous mode. In this case, the amount of GNPs was fixed to 60mg as the highest ratio of the fluorescence signal intensity was obtained with this amount as observed in the previous case of GNP dependence.

br Cavitation number In the

Cavitation number
In the simplest reasoning one can assume that vapor bubbles appear as the pressure in the liquid drops below the vapor pressure of the liquid at the given temperature. This condition can be formulated as:where pmin is the minimum static pressure (in time or space reference) and pv is the vapor pressure at a given temperature of the liquid. Many times researchers tend to use non-dimensionalised values – in the present case this ldv is the pressure coefficient Cp (also known as the Euler number) defined as:where p0 and v0 are reference pressure and velocity (again at a reference time and space). Combining Eqs. (1) and (2) reveals the pressure coefficient for the moment when cavitation first occurs:
cp, min is a negative number, which is a function of geometry and the velocity. If one could obtain the value of cp, min then the reference pressure p0,cav at which cavitation would first appear could be determined:which is now dependent on the geometry, fluid, fluid temperature and the velocity of the flow.
What Diether Thoma derived in 1920’ is a form of the Euler number (Eq. (2)). The most fundamental non-dimensional parameter, which is since then utilized for evaluating the potential for cavitation – the cavitation number σ is written as:
Every flow, cavitating or not, can be attributed by a cavitation number, its value again depends on the geometry, fluid, fluid temperature and the velocity of the flow. The conditions at which cavitation first appears can also be written as:where index i stands for “incipient” and σi for incipient cavitation number. Lowering the value of cavitation number results in the appearance of cavitation or the increase of extent of already present cavitation.

Experiment
The experiments (and results) can be divided into 5 general parts:

Results
The test parameters included numerous conditions where the flow rate, pressure, temperature and water gas content was varied. We varied the pressure in the reservoir (pa) in the range between 1 and 5bar, the flow rate between 80 and 150 L/min, temperature of the water from 20 to 70°C and the gas content from 11.1mggas/Lwater (degassed) to 30.1mggas/Lwate (untreated water).
For easier representation of the results we will, for the time being, define the cavitation number σ by the pressure inside the section upstream of the Venturi (pc, measured in point SPc, Fig. 2), the velocity at the throat of the Venturi (vth, given by the flow rate divided by the throat cross-section) and the vapor pressure and density at the fluid temperature:
According to Eq. (7) the cavitation number was varied between σ=1.5 and σ=1.7.

Conclusions
Fig. 16 shows some of the more commonly used geometries by different research groups [4,12,23,29] – hopefully our present paper made it clear how vastly different cavitation will form on such devices, and that the tests cannot be simply compared.
Moreover, in the present study we have only pointed to the most obvious issues (geometry, flow velocity, temperature and gas content) and have omitted more subtle influences such as the size of the device [30] and flow tract surface roughness [31] on the length, dynamics and aggressiveness of cavitating flow.
To conclude we would like to give the following suggestions for the future reports, which will (we hope) make the research in the filed more transparent and repeatable and will consequently enable faster ldv progress of the science and technology:

Introduction
The direct methanol fuel cell (DMFC) is an electrochemical device using methanol as fuel for directly producing electrical power. With the advantages of simple structure, long lifetime, easy fuel storage, high energy density and ambient operating temperature, DMFC is expected as an alternative cell for replacing of the conventional chargeable batteries [1,2]. Although very promising, there still are several technical problems that restrict the commercialization of DMFC. For example, methanol crossover, which is one of the most serious barriers, limits the promotion and commercial application of DMFC [3–5].

br Conclusions In order to evaluation the effects of

Conclusions
In order to evaluation the effects of ultrasonic irradiations, concentration of initial reagents and reaction time on formation [Cu4(MBT)4] or [Cu6(MBT)6] copper(I) metal-organic nanomaterials, we designed some experiments and synthesized six samples under different conditions. In the samples which synthesized with low concentrations of initial reagents, if we used the reaction time of 20min, both of [Cu6(MBT)6] (1) and [Cu4(MBT)4] (2) were formed but the amount of 2 is very low in the mixture. If we used the reaction time of 60min, pure phase of [Cu6(MBT)6] (1) was obtained. The tetranuclear cluster of [Cu4(MBT)4] (2) is the kinetically stable product which is formed at the initial time of the reaction and as the time went, it glycogen phosphorylase converts to thermodynamically stable product of [Cu6(MBT)6] (1) with hexanuclear cluster unit. If we used high concentrations of initial reagents, mixture of these two compounds will be formed again. Because in higher concentration of initial reagents, there was not enough time for conversion all amounts of kinetically stable product of [Cu4(MBT)4] (2) to thermodynamically stable product of [Cu6(MBT)6] (1). In the samples which synthesized with low concentration of initial reagents, against to those synthesized with high concentration of initial reagents, the ultrasonic irradiation does not have any effect on formation of any special morphology. In the samples which synthesized with high concentrations of initial reagents, if we consider 20min for the reaction time, mixture of 1 and 2 with the nanocube, nanoparticle and nanosheet morphologies and various sizes were formed. As the time went in, no change in morphology was seen but the size distribution of these nanostructures became narrower. Because of Ostwald ripening process small nanostructures were dissolved in solution and large structures were grown. In the samples which synthesized with low concentrations of initial reagents, diffuse control growth of nanostructures was occurred and large nanostructures were formed. But in the samples which synthesized with low concentrations of initial reagents, nucleation rate is very high and there was not enough time for growth process of the nucleus. Thus finally we have wide size distribution of nanostructures.

Acknowledgements
The authors would like to acknowledge the financial support of University of Tehran for this research under Grant number 01/1/389845.

Introduction
The main methods of developing high-viscosity oil fields are as follows [1]:
For the transportation of such high-viscosity fluids, different methods for increasing fluidity are used: heating, mixing of high-viscosity oil with low-viscosity oil and their joint pumping, mixing and pumping with water and addition of various reagents, for example, depressants [2]. These methods are rather expensive, since they require either considerable energy or the use of a considerable amount of various substances and the subsequent additional treatment of oil.
The effects of cavitation induced by ultrasound in liquid media and its influence on chemistry and processing have been studied for many years under the umbrella title of sonochemistry [3]. Ultrasonic treatment is one of the most promising alternative methods for affecting a fluid both under well conditions and on surface. It is known, that under well conditions ultrasonic treatment can lead to such effects as increase of fluid penetration into capillaries due to the sonocapillary effect, increase of fluid mobility, detachment of paraffinic and other deposits from the rock [4–6]. Under well and surface conditions, ultrasound can lead to de-emulsification [7–9] and to viscosity reduction [10–12].
Various effects can cause the viscosity reduction of oil under the influence of ultrasound. First, ultrasonic oscillations of the media lead to a temperature increase due to energy dissipation. Apart of that ultrasonic waves increase the surrounding pressure, which in turn also leads to a temperature increase. These two effects were described in [10]. The authors of [10] suggested a model, which enables to evaluate these effects numerically. In the article, the modelling results were compared with results of experiments, in which the oil recovery from a saturated core sample was measured. In these experiments, the oil recovery was measured and calculated each 10min after start of ultrasonic treatment of the core sample. The experiments lasted 60min. During the first 30min of the experiments authors report a mismatch between the experimental and calculated results, which they explain by the instability of the output power of the ultrasonic generator. After the 30min, the calculated and measured results show relatively good agreement. While the model and the experimental results are a good evidence for the change of viscosity of oil due to pressure and temperature changes, there are also another aspects, which contribute to the increase of oil recovery in the presence of an acoustic field, which should be taken into account. These are the increase of fluid mobility, the decrease of interfacial tension and the redistribution of pressure and temperature.

br Materials and methods br Results and discussion br

Materials and methods

Results and discussion

Conclusion
The influence of FSFP ultrasound treatment on the stability of phenolic acids was investigated by analyzing ultrasound factors, degradation kinetics and mechanism. The results showed that the ultrasonic temperature, frequency, sweep range, sweep cycle, and pulse ratio significantly affected the degradation rates of caffeic and sinapic acids. Relatively high temperature, frequency away from the resonance frequency, narrow sweep range, moderate sweep cycle, and relatively low or high pulse ratio were found to be beneficial to maintain the high stability of phenolic acids. The degradation kinetics of caffeic and sinapic acids under FSFP ultrasound treatment were conformed to zeroth-order kinetic model at 10–50°C. Moreover, higher k and lower t1/2 indicated that FSFP ultrasound had a stronger destroying effect on sinapic thapsigargin manufacturer than caffeic acid. The FT-IR and HPLC-ESIMS results indicated that the decomposition (decarboxylation) and polymerization reactions occurred in caffeic and sinapic acids under FSFP ultrasound. The results obtained in this study proved a significant sonochemical effect of FSFP ultrasound on the stability of phenolic acids in a model system.

Acknowledgements
The authors wish to extend their appreciation for the supports provided by the Senior Professional Research Start-up Fund of Jiangsu University, China (No. 10JDG121), and the Priority Academic Program Development Fund of Jiangsu Higher Education Institutions (PAPD) for their financial support toward the study.

Introduction
Poly (vinylidene fluoride) (PVDF) membranes find application in a number of water treatment and separation processes and are an ongoing subject of much research due to their recognised beneficial properties such as high mechanical and thermal stability, and resistance to chemical degradation [1,2]. There are many routes that have been developed to synthesise PVDF membranes for various applications, with non-solvent induced phase separation (NIPS) being one of the more common techniques. Several research reports have shown that the final properties of the membranes produced during a NIPS process is dependent on a number of factors such as the type of dissolving solvent, the duration of dope exposure to evaporation, and the type, temperature and impurities present in the coagulating bath [2–5]. While significant attention has been paid to properties influenced by coagulation, research is still emerging on the equally important conditions of polymer dissolution [1,6–8]. For example, Lin et al. [7] showed that varying the temperature of dissolution of the PVDF polymer from 50°C to 110°C resulted in an order of magnitude change in the size of the membrane semicrystalline particles from 0.5 to 15µm. Several other researchers have confirmed the strong effect of pre-coagulation dope preparation route on the morphological and surface properties of PVDF membranes such as porosity, crystallinity, surface energy, etc. [1,6,8,9]. The lasting effect of polymer dissolution temperature has been attributed to differences in the degree of dissolution of polymer crystals in the dopes [7] as well as to differences in the extent of unfolding of the polymer molecular chains [1] prior to the membrane forming stage.
These changes to the polymer ultimately affect the practical properties of the membranes which also need to be analysed. For example, Wang et al. [1] demonstrated that the significant morphological effects arising from variations in the dissolution temperature of PVDF polymer have great impact on membrane distillation performance with flux decreasing as a result of decreasing membrane porosity as the temperature of polymer dissolution increased from 50 to 120°C. However, the results reported by Gugliuzza and Drioli [6] for membrane produced with dopes treated to lower pre-coagulation temperatures between 30°C and 60°C showed increasing membrane distillation flux with increasing dope treatment temperature. Gugliuzza and Drioli related the positive effect of temperature on flux to the observed positive correlation between temperature and membrane pore sizes. The difference in the flux trends with dissolution temperature in these two reports may have resulted from difference in the temperature range for the two sets of experiments or it may relate to the use of different solvents for phase inversion. Wang et al. [1] used water for the phase inversion of their membranes while Gugliuzza and Drioli [6] used propanol. The important point for our purpose, however, is the demonstrated strong effect of dope dissolution condition on membrane performance. Recently, Ahmad et al. [8] showed that the morphological impact and crystalline re-structuring arising from changes in the dope dissolution temperature has significant effects on the membrane protein binding ability for immunological analytical application. They showed that the protein binding properties of membranes produced from dopes dissolved above a critical temperature value of 40°C were governed by the membrane porosity but when produced from dopes dissolved at lower temperature, the binding properties were governed by the membrane crystalline structure. Higher surface area for protein binding due to higher porosity and greater electrostatic attraction of the more polar β phase to protein were advanced to explain the results.