VARIATIONS OF CLIMATE PARAMETERS AND THEIR IMPACT ON CABERNET SAUVIGNON AND SAUVIGNON BLANC PHENOLOGY IN CONDITIONS OF CENTRAL SERBIA

Research carried out in vineyard of King Peter I Karadjordjevic-Royal Winery at Oplenac-Topola municipality, on Sauvignon blanc and Cabernet sauvignon. Vineyard planted with Sauvignon blanc is geographically positioned at GPS coordinates N 44° 14' 4" and E 20° 41' 15" and Cabernet sauvignon is geographically positioned at GPS coordinates N 44° 14' 35" and E 20° 41' 22". Climat parameters (series from 1982-2011 year) included following parameters: mean monthly, vegetation (april-october) and annual temperature, active and effective temperature, precipitation distribution (annual and vegetation) and wind direction. Phenological observation included beginning and end of following phenophases: bleeding, budbreakt, shoot growing, flowering, berry development and ripening. The greatest variation Sauvignon blanc manifested in duration of grape ripening which is in 2010. lasted 46 days while in 2011. lasted 34 days. Cabernet sauvignon in 2011. had a lower number of days that have passed from bleeding to full maturity (209 days) compared to 2010., when it passed 217 days

A Comparative Analysis of Two Approaches in Envelope Tracking Power Supplies for Satellite Applications

In modern telecommunication systems, the requirements for amount of transmitted data are increasing. In order to transmit as much information as possible for a given spectral band, both amplitude and phase modulation are applied. The main power consumers in transmitters are power amplifiers(PA), placed in the output stage. During the last decade, a lot of efforts have been invested in optimization of the efficiency of RF power amplifiers. One of notable techniques is Kahn’s envelope and restoration (EER) principle, where highly efficient envelope tracker and non-linear RF amplifier (e.g. class E, F) are combined. In this paper, two different approaches in envelope tracking are presented. The first approach is based on an analog multiplexer and a linear regulator in series, while the second tracker consists of PWM controlled switches and the fourth order output filter. Both trackers are supplied with highly efficient (96%) switch-capacitor based multilevel power converter, which acts as a voltage divider. Additionally, the comparison between two prototypes of the first approach, with Si and GaN based transistors is presented. Experimental results show that peak efficiencies are 73% (Si) and 75% (GaN), in the case of a 5 MHz 64QAM reference signal, with 10 W average output power. For the second approach, different filter prototypes are analysed. Moreover, their impact on envelope signal processing is backed up with the simulation results and the experimental results for tracking of a 2 MHz 64QAM reference are presented, with 78% achieved efficiency (Si technology) and 9 W average output power

Facile synthesis of layered hexagonal MoS2

In this work synthesis of layered molybdenum sulphide (MoS2) through a temperature-controlled thermal evaporation approach is reported. Simultaneous co-evaporation of molybdenum trioxide (MoO3) and sulphur in an argon environment is employed. The as-deposited thin films are characterized by diffraction and microscopy

Atomically thin layers of MoS2 via a two step thermal evaporation-exfoliation method

Two dimensional molybdenum disulfide (MoS2) has recently become of interest to semiconductor and optic industries. However, the current methods for its synthesis require harsh environments that are not compatible with standard fabrication processes. We report on a facile synthesis method of layered MoS2 using a thermal evaporation technique, which requires modest conditions. In this process, a mixture of MoS2 and molybdenum dioxide (MoO2) is produced by evaporating sulfur powder and molybdenum trioxide (MoO3) nano-particles simultaneously. Further annealing in a sulfur-rich environment transforms majority of the excess MoO2 into layered MoS2. The deposited MoS2 is then mechanically exfoliated into minimum resolvable atomically thin layers, which are characterized using micro-Raman spectroscopy and atomic force microscopy. Furthermore Raman spectroscopy is employed to determine the effect of electrochemical lithium ion exposure on atomically thin layers of MoS2

Degradation of crystal violet over heterogeneous TiO2-based catalysts: The effect of process parameters

In this study, modified sol-gel method was employed to synthesize the pure and Zr-doped titania catalysts. Brunauer-Emmett-Teller (BET) method was applied to determine porosity, X-ray diffraction (XRD) analysis was used to study crystal structure, scanning electron microscopy (SEM) was used to investigate morphology and Fourier transform infrared spectroscopy (FTIR) was used to examine surface properties/total acidity of the obtained catalysts samples. Photocatalytic activity was tested in the reaction of crystal violet (CV) dye decolourization/degradation under UV light irradiation. The effects of several photocatalysis operational parameters were considered, such as catalyst dosage, initial dye concentrations, duration of UV irradiation treatment, as well as catalysts calcination temperatures and dopant amounts. The obtained results indicated faster dye decolourization/degradation with the increase of the catalyst dosage and the decrease of initial CV concentrations. The Zr-doping affects photocatalytic properties, i.e. CV decolourization/degradation of the prepared catalytic materials. Thus, addition of 5 wt.% of ZrO2 to titania increases photocatalytic effect for similar to 15% and addition of 10 wt.% of ZrO2 improves the photocatalytic efficiency of titania for nearly 30%

Nanoscale mechanical control of surface electrical properties of manganite films with magnetic nanoparticles

Mechanical control of electrical properties in complex heterostructures, consisting of magnetic FeOx nanoparticles on top of manganite films, is achieved using atomic force microscope AFM based methods. Under applied pressure of the AFM tip, drop of the electrical conductivity is observed inducing an electrically insulating state upon a critical normal load. Current and surface potential maps suggest that the switching process is mainly governed by the flexoelectric field induced at the sample surface. The relaxation process of the electrical surface potential indicates that the diffusion of oxygen vacancies from the bulk of the manganite films towards the sample surface is the dominant relaxation mechanism. The magnetic FeOx nanoparticles, staying attached to the sample surface after the rubbing, protect the underlying manganite films and provide stability of the observed resistive switching effect. The employed mechanical control gives a new freedom in the design of resistive switching devices since it does not depend on the film thickness, and biasing is not neede

Decolorization of crystal violet over TiO2 and TiO2 doped with zirconia photocatalysts

Titania based catalyst and TiO2 doped with zirconia were prepared by modified sol-gel method. The synthesized catalysts samples were characterized by BET, XRD, SEM and FTIR techniques. Photocatalytic activity was tested in the reaction of crystal violet (CV) dye decolorization/decomposition under UV light irradiation. The effect of several operational parameters, such as catalyst dosage, initial dye concentrations, duration of UV irradiation treatment and number of reaction cycles were also considered. The obtained results indicated faster dye decolorization with the increase of the catalyst amount and a decrease of initial CV concentrations. An influence of doping with zirconia on the physico-chemical properties of bare titania was studied. The doping procedure had affected photocatalytic properties of the final catalytic material, and had improved photocatalytic performances of doped catalyst on crystal violet decolorization/degradation in comparison to bare titania

Urgent need to clarify the definition of chronic critical limb ischemia - a position paper from the European Society for Vascular Medicine

Chronic critical lower limb ischemia (CLI) has been defined as ischemia that endangers the leg. An attempt was made to give a precise definition of CLI, based on clinical and hemodynamic data (Second European Consensus). CLI may be easily defined from a clinical point of view as rest pain of the distal foot or gangrene or ulceration. It is probably useful to add leg ulcers of other origin which do not heal because of severe ischemia, and to consider the impact of frailty on adverse outcome. From a hemodynamic viewpoint there is no consensus and most of the existing classifications are not based upon evidence. We should thus propose a definition and then validate it in a prospective cohort in order to define the patients at major risk of amputation, and also to define the categories of patients whose prognosis is improved by revascularisation. From today\u27s available data, it seems clear that the patients with a systolic toe pressure (STP) below 30 mmHg must be revascularised whenever possible. However other patients with clinically suspected CLI and STP above 30 mmHg must be evaluated and treated in specialised vascular units and revascularisation has to be discussed on a case by case basis, taking into account other data such as the WiFi classification for ulcers.In conclusion, many useful but at times contradictory definitions of CLI have been suggested. Only a few have taken into account evidence, and none have been validated prospectively. This paper aims to address this and to give notice that a CLI registry within Europe will be set up to prospectively validate, or not, the previous and suggested definitions of CLI