Particle swarm optimization for determining shortest distance to voltage collapse

This paper describes an algorithm for computing shortest distance to voltage collapse or determination of CSNBP using PSO technique. A direction along CSNBP gives conservative results from voltage security view point. This information is useful to the operator to steer the system away from this point by taking corrective actions. The distance to a closest bifurcation is a minimum of the loadability given a slack bus or participation factors for increasing generation as the load increases. CSNBP determination has been formulated as an optimization problem to be used in PSO technique. PSO is a new evolutionary algorithm (EA) which is population based inspired by the social behavior of animals such as fish schooling and birds flocking. It can handle optimization problems with any complexity since mechanization is simple with few parameters to be tuned. The developed algorithm has been implemented on two standard test systems.     

Ground state structural stability of ordered fcc- and bcc-based LiAl compounds under first and second nearest-neighbour pair approximation

Self-consistent local density electronic structure calculations have been performed on a series of ground state ordered superstructures of lithium-aluminium alloys spanning the entire concentration range. These structures are based on both fcc and bcc lattices under the first and second nearest neighbour pair approximation which is adequate to stabilize all the stable and metastable phases of the Li---Al system. Using the efficient tight-binding linear muffin-tin orbital (TB-LMTO) method, we have calculated the volume dependent total ground state energies and the systematic trends in various cohesive and electronic properties at zero temperature, as a function of Li concentration. The predicted heats of formation for all the different ground state superstructures result in a representative stability profile, which shows that the L1₂, B32 and DO₃ structures are the most stable amongst various phases having Al₃Li, AlLi and AlLi₃ compositions, respectively. Moreover, we have parameterized the cohesive energies using the Connolly-Williams cluster expansion method and estimated the effective many-body interactions for the fcc lattice in an octahedron-tetrahedron cluster approximation, and for the bcc lattice in an irregular tetrahedron cluster approximation. These volume dependent but configuration (as well as concentration) independent interactions coming out of the TB-LMTO-CWM approach are not only important for first principles calculation of phase diagram but are also useful for predicting the evolutionary path of ordering processes.     

Fast and accurate automatic registration for MR-guided procedures using active microcoils

A fast, robust, accurate, and automatic registration technique based on magnetic resonance (MR) active microcoils (active markers) for registration of tracked medical devices to preprocedural MR-images is presented. This allows for a straight-forward integration of position measurement systems into clinical procedures. The presented method is useful for guidance purposes in clinical applications with high demands on accuracy and ease-of-use (e.g., neurosurgical or orthopedic applications). The determination of the positions of the active markers is integrated into the preparation phase of the actual MR imaging scan. The technique features a generic interface using DICOM standards for communication with navigation workstations linked to an MR system. The position of the active markers is fixed with respect to a reference system of an optical positioning measurement system (OPMS) and thus the coregistration of the MR system and the OPMS is established. In a phantom study, a mean overall targeting accuracy of 0.9+/-0.1 mm was achieved and compared favorably to results obtained from manual registration tests (1.8+/-0.3 mm) carried out in parallel. For a test person trained for both registration methods, workflow improvements of 3-6 min per registration step were found. The need for manual interaction is entirely eliminated thus avoiding user-bias, which is advantageous for the usage in clinical routine. The method improves the ease-of-use of tracking equipment during stereotactic guidance. The method is finally demonstrated in a volunteer study using a model of a Mayfield skull clamp with integrated active and optical reference markers.     

Zinc oxide nanorods modified indium tin oxide surface for amperometric urea biosensor

ZnO nanorods (ZnONR) grown onto indium-tin-oxide (ITO) coated glass surface using zinc nitrate hexahydrate/hexamethylenetetramine (HMT) in aqueous phase has been utilized for urea biosensor. Urease (Urs) was immobilized onto ZnONR/ITO at physiological pH via electrostatic interactions between Urs and ZnO to fabricate Urs/ZnONR/ITO bioelectrode. ZnONR/ITO electrode has been characterized using XRD, FE-SEM techniques and Urs/ZnONR/ITO bioelectrode using electrochemistry. The XRD and FE-SEM measurements confirm the formation of ZnO nanorods in wurtzite structure. Cyclic voltammetric and amperometric measurements on the Urs/ZnONR/ITO biolectrode for urea concentrations in the range of 1-20 mM reveal 0.4 microA mM(-1) sensitivity, with a response time of 3 seconds, and a detection limit of 0.13 mM. The Michaelis-Menten constant (Km) was calculated to be 9.09 mM. Results indicate that ZnO nanorods provide suitable microenvironment for urease immobilization and can be utilized in biosensor design and other biological applications.     

Electrical properties of electrodeposited zinc selenide (ZnSe) nanowires

In this work, zinc selenide (ZnSe) nanowires were fabricated on indium-tin oxide coated glass substrate via template-assisted electrodeposition method from an electrolytic solution of zinc (II) sulphate (ZnSO₄·7H₂O) and selenium dioxide (SeO₂). ZnSe nanowires of diameter 100 nm have been fabricated using polycarbonate track-etch membrane. Electrodeposition was done at 30 °C temperature and the length of the nanowires was controlled by adjusting the deposition time. Both morphological and electrical characteristics were studied. Sample characterization was done using scanning electron microscope and X-ray diffraction. I–V measurements reveal that the ZnSe nanowires have non-linear behavior like Schottky diode characteristics. Further, the ZnSe nanowires were used in astable multivibrator which acts as capacitor to give conventional output behavior. The temperature dependent capacitive properties of ZnSe nanowires reveal that ZnSe nanowire can be used as temperature sensor.     

Additive manufactured portable vertical axis windmill

ABSTRACT

The vertical axis windmill is a type of wind turbine in which the main rotor shaft is set vertically. The main aim of this is to make it more compatible and accessible. According to the research, there is plenty of enough wind available globally to meet the human energy requirements – if it is harvested on a large scale effectively. If the wind turbine efficiency is increased, then there is a chance for more power generation and to drastically decrease the use of power generators which are rather expensive and also cause pollution. In comparison to horizontal axis wind turbines, the vertical axis wind turbines may be efficient as them and are also cheaper to build and maintain. In this paper, we designed and fabricated a vertical axis wind turbine and fabricated the same using the ‘3D printing technique’ which is one of the additive manufacturing processes used now.     

Effect of pressure and time on bioactive content,PPO inactivation,physicochemical and sensory properties of aonla (Emblica officinalis) juice during hydrodynamic cavitation processing

Food Science and Biotechnology - Physical and nutritional attributes of aonla juice treated with hydrodynamic cavitation (HC) at a pressure range of 5–15 psi and time between 5 to...     

Ring Oscillator for 60 Meter Bandwidth

The 60-meter band range is tremendously useful in telecommunication, military and governmental applications. The I. T. U. (International Telecommunication Union) required isolationism to former radio frequency services because the various frequency bands are extremely overloaded. The allocation of new frequency bands are a lengthy procedure as well as time taking. As a result, the researchers use bidirectional, amateur radio frequency communication for 60-meter band, usually the frequency slot of 5250–5450 KHz, although the entire band is not essentially obtainable for all countries. For transmission and reception of these frequencies, a local oscillator is used in the mixer unit to generate the local signal for mixing the input and reference signals. For this function different type of oscillators are used. In this paper, a three-stage ring oscillator is designed with 1 V supply. Ring oscillators (RO) is the base to explore like to identifying, specify with modelling resources in the disparity in behaviour of the circuit in terms of industrialized design and layout parameters. This type of oscillators are free from noise as inductor is not used to the circuit as in LC oscillator, Heartly oscillator, Colpitt and tuned oscillators. The present approach of circuit designing, the scaling of CMOS (Complementary Metal Oxide Semiconductor) transistor will moderate, the procedure variability. In the forthcoming article, a ring oscillator with fixed capacitor (1 pF) and with variable capacitors (1 to 100 pF) is analysed. The frequency analysis with different capacitor is performed. The total delay of 3-stage oscillator is 4.82 ns with 5.2 MHz oscillation frequency. The overall Power dissipation of the circuit is 1.852 μW at 1 V supply. The simulation analysis is performed on 45 nm CMOS technology with both transistor width are 278 and 420 nm.     

Impact of Drain Underlap and High Bandgap Strip on Cylindrical Gate All Around Tunnel FET and its Influence on Analog/RF Performance

Silicon - This paper comprises of design and analysis of novel gate all around (GAA) cylindrical tunnel field effect transistor (TFET) using technology computer aided designing (TCAD) tool. The...