Search Results (5)

Permanent makeup (PMU) is a popular application for the correction of face and body imperfections. It can be applied over the facial area to correct the shape and color of eyebrows, to the eyelids to create permanent eyeliner shapes, and the lips to create permanent lipliner and lip shading features. Furthermore, its “medical” use on the scalp and men’s facial hair area to camouflage hair follicles and to cover hairless areas makes it popular for hair transplants. No matter how useful these procedures are, there are always mistakes and the factor of bad application which raises the number of patients who want to “remove” it or “correct” it on their face or body. In order to find a non-laser solution for PMU removal, we investigated the decolorization capacity of common plants and plant origin extracts on mouse models. Two methods were used for PMU decolorization. The first one included the use of traditional tattooing with needles combined with plant origin extracts applied over the tattooed area. The second one included the use of electroporation technology application with the combination of plant origin materials to remove the PMU colorants over the tattooed area. In both cases, the permanent makeup colorants for eyebrows, eyeliners, and lipliners were applied in vivo. Full article

Permanent make-up (PMU) has become a very popular application over the last few years. The ingredients of PMU inks, used over the face area, are organic and inorganic substances very close to the chemical composition of tattoo inks. As the application rates increase, the demand for PMU removal rises. The aim of this study is to assess the decolorization of PMU inks using preparations originating from different plant sources. The leaves of Pelargonium zonale (PE) were extracted with water for 48 h. The Total Phenolic Content (TPC) of the extract was determined using the Folin–Ciocalteu technique reaching 201.34 ± 4.57 μg Gallic Acid Equivalents (GAE)/mL of extract. The antioxidant activity of the extract was 20.87 ± 0.36 μg of Trolox equivalents (TE)/mL and 3.56 ± 0.43 mg FeSO₄×7H₂O mL of extract when assessed by 2,2-diphenyl-1-picrylhydrazyl (DPPH) or ferric reducing antioxidant power (FRAP) assay respectively. The decolorization potential of PE leaf extract on five commercially available PMU inks of different hues was assessed by UV-Vis spectrophotometry in comparison to polyphenol oxidases enzyme (PPO). The results demonstrated higher absorption reduction that indicates decolorization potential for the inks that have mainly ferrous oxides as colorants. Full article

Due to the rapid development of phasor measurement units (PMUs) and the wide area of interconnection of modern power systems, the security of power systems is confronted with severe challenges. A novel framework based on data for static voltage stability margin (VSM) assessment of power systems is presented. The proposed framework can select the key operation variables as input features for the assessment based on partial mutual information (PMI). Before the feature selection procedure is completed by PMI, a feature preprocessing approach is applied to remove redundant and irrelevant features to improve computational efficiency. Using the selected key variables, a voltage stability assessment (VSA) model based on iterated random forest (IRF) can rapidly provide the relative VSM results. The proposed framework is examined on the IEEE 30-bus system and a practical 1648-bus system, and a desirable assessment performance is demonstrated. In addition, the robustness and computational speed of the proposed framework are also verified. Some impact factors for power system operation are studied in a robustness examination, such as topology change, variation of peak/minimum load, and variation of generator/load power distribution. Full article

Synchronous distributed generators (SDGs) significantly affect recloser–fuse coordination due to the high fault current contribution. This paper proposes a separated phase–current control using inverter-based distributed generators (IBDGs) to remove the effects of fault current contributions from SDGs during unsymmetrical faults. The three-phase current produced by IBDGs is independently controlled. While the total fault current is reduced by adjusting the current phase angle in the faulty phase, the energy in the DC-link capacitor ( $C_{dc}$ ) is delivered to the grid in order to avoid the rise of DC-link voltage ( $V_{dc}$ ) by means of injection of the active current into the nonfaulty phase. To maintain the proper grid voltage, the voltage regulation feature is installed in the IBDGs. Moreover, current estimations programmed within the IBDGs are introduced to avoid the performance degradation of separated phase–current controls caused by phasor measurement units (PMUs). The dynamic performance of the separated phase–current controls using IBDGs was evaluated using an IEEE 34-node radial test feeder. According to the simulation results, the IBDGs could eliminate the effects of fault current contributions from the SDG without interruption since the disconnections caused by excessive $V_{dc}$ were prevented. They could also regulate the grid voltage in the nonfaulty phase. Full article

Smart grid (SG) will be one of the major application domains that will present severe pressures on future communication networks due to the expected huge number of devices that will be connected to it and that will impose stringent quality transmission requirements. To address this challenge, there is a need for a joint management of both monitoring and communication systems, so as to achieve a flexible and adaptive management of the SG services. This is the issue addressed in this paper, which provides the following major contributions. We define a new strategy to optimize the accuracy of the state estimation (SE) of the electric grid based on available network bandwidth resources and the sensing intelligent electronic devices (IEDs) installed in the field. In particular, we focus on phasor measurement units (PMUs) as measurement devices. We propose the use of the software defined networks (SDN) technologies to manage the available network bandwidth, which is then assigned by the controller to the forwarding devices to allow for the flowing of the data streams generated by the PMUs, by considering an optimization routine to maximize the accuracy of the resulting SE. Additionally, the use of SDN allows for adding and removing PMUs from the monitoring architecture without any manual intervention. We also provide the details of our implementation of the SDN solution, which is used to make simulations with an IEEE 14-bus test network in order to show performance in terms of bandwidth management and estimation accuracy. Full article