Enhanced photocatalytic degradation of RO16 dye using Ag modified ZnO nanopowders prepared by the solvothermal method

In this work, Zn(CH3 COO)(2) 2 H-2 O with AgNO3 content from 0 to 6 mol% was solvothermally treated at 120 C for 18 h in the presence of poly(vinyl pyrrolidone), ethylene glycol and sodium hydroxide. The structural , microstructural and photocatalytic properties of the unmodified and Ag modified ZnO powders have been investigated by the XRPD, FESEM, TEM, UV-vis, Raman and BET techniques. The Ag modified samples consist of ZnO nanocrystals and metallic Ag on the surface. The average crystallite size of all samples was about 20 nm. The FESEM revealed the uniformity in size and approximately spherical shape of ZnO nanopar-ticles. The BET data suggest that all prepared samples are mesoporous. All prepared samples showed higher photocatalytic efficiency in the degradation of the Reactive Orange 16 (RO16) azo dye than the commercial ZnO. In addition, Ag modified ZnO powders, especially those with 1.5 and 0.75 mol% of Ag, were more efficient than the unmodified one

Variranje broja klasova po jedinici površine useva u različitim gustinama setve pšenice

Broj klasova po jedinice površine ima značajan uticaj na formiranje prinosa kroz osobine, dužinu klasa, broj klasaka u klasu, broj semena u klasu, masu klasa, masu semena u klasu i masu 1000 semena. Cilj rada je izučavanje variranja broja klasova pšenice u različitim rokovima i gustinama setve. U istraživanja su uključene dve sorte pšenice (Prima i Simonida), u ogledu sa dva roka i tri gustine setve u dve vegetacione sezone. Rezultati su pokazali značajne razlike u broju klasova m-2, između sorti, prema gustini setve, po rokovima setve i između dve vegetacione sezone. U obe vegetacione sezone, najmanji broj klasova m-2 je nađen pri gustini setve 350 semena m-2 kod obe sorte i to 504,50 i 350,33 kod Prime i 520,50 i 371,83 kod Simonide, dok je najveći broj klasova m-2 utvrđen pri najvećoj gustini setve (750 semena) i to 558,32 i 372,50 kod sorte Prima i 590,17 u prvoj i 622,17 klasova kod sorte Simonida u drugoj godini. Broj klasova m-2 je varirao zavisno od genotipa, gustine setve, vremena setve i uslova u vegetacionoj sezoni

Water Induced Ferroelectric Switching: The Crucial Role of Collective Dynamics

The interaction mechanisms of water with nanoscale geometries remain poorly understood. This study focuses on behaviour of water clusters under varying external electric fields with a particular focus on molecular ferroelectric devices. We employ a two-fold approach, combining experiments with large-scale molecular dynamics simulations on graphene nanoribbon field effect transistors. We show that bilayer graphene nanoribbons provide stable anchoring of water clusters on the oxygenated edges, resulting in a ferroelectric effect. A molecular dynamics model is then used to investigate water cluster behaviour under varying external electric fields. Finally, we show that these nanoribbons exhibit significant and persistent remanent fields that can be employed in ferroelectric heterostructures and neuromorphic circuits

Clinical Impact of Patient-Prosthesis Mismatch After Aortic Valve Replacement With a Mechanical or Biological Prosthesis

BACKGROUND: Patient-prosthesis mismatch (PPM) may impair functional capacity and survival after aortic valve replacement. This study aimed to investigate the impact of PPM on long-term survival and quality of life after mechanical and biological aortic valve replacement. METHODS: This study included 595 consecutive patients who had undergone isolated aortic valve replacement. Patients were divided into 2 groups according to prosthesis type. The baseline and operative characteristics, survival rates, complications, and quality of life of the groups with and without PPM were compared for up to 6 years. The PPM calculation was performed using the effective orifice area value provided by the manufacturer divided by the patient\u27s body surface area. RESULTS: The moderate to severe PPM rates were 69.8% and 3.7% after biological and mechanical prosthesis implantation, respectively. Mean survival for patients in the biological group who had PPM was statistically significantly shorter (50.2 months [95% CI, 45.2-55.3]) than for patients in the biological group without PPM (60.1 months [95% CI, 55.7-64.4]; P = .04). In the mechanical prosthesis group, there was no difference in mean survival between the subgroup with PPM (66.6 months [95% CI, 58.3-74.9]) and the subgroup without PPM (64.9 months [95% CI, 62.6-67.2]; P = .50). A quality-of-life questionnaire\u27s scores did not differ between the groups. CONCLUSION: Mismatch is common after biological valve implantation and statistically significantly affects long-term survival and quality of life. If the risk of PPM after implantation of a biological prosthesis is suspected, adopting strategies to avoid PPM at the time of surgery is warranted

Patterning GaSe by High-Powered Laser Beams

We report the high-powered laser modification of the chemical, physical, and structural properties of the two-dimensional (2D) van der Waals material GaSe. Our results show that contrary to expectations and previous reports, GaSe at the periphery of a high-power laser beam does not entirely decompose into Se and Ga2O3. In contrast, we find unexpectedly that the Raman signal from GaSe gets amplified around regions where it was not expected to exist. Atomic force microscopy (AFM), dielectric force microscopy (DFM), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX) results show that laser irradiation induces the formation of nanoparticles. Our analyses demonstrate that, except for a fraction of Ga2Se3, these nanoparticles still belong to the GaSe phase but possess different electrical and optical properties. These changes are evidenced in the increased Raman intensity attributed to the near-resonance conditions with the Raman excitation laser. The elemental analysis of nanoparticles shows that the relative selenium content increased to as much as 70% from a 50:50 value in stoichiometric GaSe. This elemental change is related to the formation of the Ga2Se3 phase identified by Raman spectroscopy at some locations near the edge. Further, we exploit the localized high-power laser processing of GaSe to induce the formation of Ag–GaSe nanostructures by exposure to a solution of AgNO3. The selective reaction of AgNO3 with laser-irradiated GaSe gives rise to composite nanostructures that display photocatalytic activity originally absent in the pristine 2D material. The photocatalytic activity was investigated by the transformation of 4-nitrobenzenethiol to its amino and dimer forms detected in situ by Raman spectroscopy. This work improves the understanding of light–matter interaction in layered systems, offering an approach to the formation of laser-induced composites with added functionality

Quantifying the contribution of material and junction resistances in nano-networks

Networks of nanowires and nanosheets are important for many applications in printed electronics. However, the network conductivity and mobility are usually limited by the inter-particle junction resistance, a property that is challenging to minimise because it is difficult to measure. Here, we develop a simple model for conduction in networks of 1D or 2D nanomaterials, which allows us to extract junction and nanoparticle resistances from particle-size-dependent D.C. resistivity data of conducting and semiconducting materials. We find junction resistances in porous networks to scale with nanoparticle resistivity and vary from 5 Ohm for silver nanosheets to 25 GOhm for WS2 nanosheets. Moreover, our model allows junction and nanoparticle resistances to be extracted from A.C. impedance spectra of semiconducting networks. Impedance data links the high mobility (~7 cm2/Vs) of aligned networks of electrochemically exfoliated MoS2 nanosheets to low junction resistances of ~670 kOhm. Temperature-dependent impedance measurements allow us to quantitatively differentiate intra-nanosheet phonon-limited band-like transport from inter-nanosheet hopping for the first time.Comment: 5 figure

Pinaceae Pine Resins (Black Pine, Shore Pine, Rosin, and Baltic Amber) as Natural Dielectrics for Low Operating Voltage, Hysteresis‐Free, Organic Field Effect Transistors

AbstractFour pinaceae pine resins analyzed in this study: black pine, shore pine, Baltic amber, and rosin demonstrate excellent dielectric properties, outstanding film forming, and ease of processability from ethyl alcohol solutions. Their trap‐free nature allows fabrication of virtually hysteresis‐free organic field effect transistors operating in a low voltage window with excellent stability under bias stress. Such green constituents represent an excellent choice of materials for applications targeting biocompatibility and biodegradability of electronics and sensors, within the overall effort of sustainable electronics development and environmental friendliness

Activism and capitalism: On the forms of engagement

This short essay aims at providing an outline for a critical reflection on the notion of activism and to bring to attention the significance for distinguishing between different forms of engagement in contemporary neoliberal societies. The article traces the history of the notion of ‘activism’ and argues that it went hand in hand with the reduction of heterogeneous political activity to immediate generic action. In order to counter such a reduction, the article relies on the work of Ellen Meiksins Wood and her critical history of the development of the liberal conception of citizenship. In conclusion, it will be argued that the conceptual significance of the notion of capitalism is crucial for distinguishing between different forms and figures of political activity - from the ‘activist’, ‘active citizen’ and what Engin Isin termed ‘activist citizenship’

Intermediation and the description of history in video games

This bachelor´s thesis analyzes the video game Red Dead Redemption and the historical use of the environment and atmosphere in the game. The theory and method used is media research and social memory studies. Two questions were asked: how does Red Dead Redemeption convey and produce the historical environment and the historical atmosphere. Furthermore subqueries/criterias were used to help answer the main questions. The analysis was divided into two parts, the first part we analyze and discuss the games historical environment and the second part analyzes and discusses the historical atmosphere of the game. The conclusion is that both the historical environment and the historical atmosphere is present in the game through picture and sound, the text only works as a guide. The picture and sound live in a symbiotic relationship and depend on each other to fully immerse the player to the game. The social memory is also highly present due to it being inspired by movies such as The good the bad and the ugly and For a fistful of dollars