Zonal Velocity Bands and the Solar Activity Cycle

We compare the zonal flow pattern in subsurface layers of the Sun with the distribution of surface magnetic features like sunspots and polar faculae. We demonstrate that in the activity belt, the butterfly pattern of sunspots coincides with the fast stream of zonal flows, although part of the sunspot distribution does spill over to the slow stream. At high latitudes, the polar faculae and zonal flow bands have similar distributions in the spatial and temporal domains.Comment: To appear in Solar Physic

Some characteristics of the solar wind inferred from the study of sodium emission from cometary nuclei

Seventeen comets, having information on sodium D-line emission during their apparition, have been studied. The heliocentric distances corresponding to the sodium emission commencement or termination epoch are found to have a dependence on the phase of the solar cycle. For comets appearing during a solar maximum the sodium emission is detectable out to greater distances than, for the comets appearing during solar minimum. The sodium emission is also found to depend on heliographic latitude of the comet. It is concluded that the spatial properties of the solar wind during a solar maximum and minimum are responsible for the observed dependence

K emission-line widths and the solar chromosphere

Closely spaced microphotometer tracings parallel to the dispersion of one excellent frame of a K-line time sequence have been utilized for a study of the nature of the K2v , K2R intensities in the case of the solar chromosphere. The frequency of occurrence of the categories of intensity ratio IK2v/IK2R are as follows: IK2v > IK2R = 45.3 per cent; IK2v = IK2R = 4.7 per cent; IK2v < IK2R = 25 per cent; IK2R = 0 = 22.3 per cent; IK2v = 0 =0.7 per cent. Two types of absorbing components are postulated to explain the pattern of observed K2v , K2R intensity ratios. One component with minor Doppler displacements acting on the normal K232 profile, where K2V > K2R, produces the cases K2v ≫ K2R , K2v = K2R , K2v < K2R . The other component arises from 'dark condensations' which are of size 3500 kms as seen in K2R. They have principally large down flowing velocities in the range 5-8 km/sec and are seen on K3 spectroheliograms with sizes of about 5000 kms, within the coarse network of emission. These 'dark condensations' give rise to the situation K2R = 0. K2-line widths are measured for all tracings where K2v , K2R are measurable simultaneously. The distribution curve of these widths is extremely sharp. The K2 emission source is identified with the bright fine mottles visible on the surface. Evidence for this interpretation comes from the study of auto-correlation functions of K2 intensity variations and the spacing between the bright fine mottles from both spectrograms and spectroheliograms. The life time of the fine mottling is 200 sec. The supergranular boundaries which constitute the coarse network come in two intensity classes. A low intensity network has the fine mottles as its principal contributor to the K emission. When the network is bright, the enhancement is caused by increased K emission due to the accumulation of magnetic fields at the supergranule boundary. The K2 widths of the low intensity supergranular boundary agree with the value found for the bright mottles. Those for the brighter network are lower than this value, similar to the K2 widths as seen in the active regions. It is concluded that bright fine mottling is responsible for the relation, found by Wilson and Bappu, between K emission line widths and absolute magnitudes of the stars. The paper discusses the solar cycle equivalents that stellar chromospheres can demonstrate and indicates a possible line of approach for successful detection of cyclic activity in stellar chromospheres

Survey and Review on Various Topology and Geographical based Routing Protocol Parameters to Ensure the QOS Parameters of VANET

Vehicular Ad Hoc Network (VANET) is a type of wireless network that allows communication between vehicles and infrastructure. One of the critical considerations in VANET is Quality of Service (QoS) parameters, which determine the network's performance. The effective management of QoS parameters is essential for VANET's reliable and efficient operation. In this research paper, we aim to explore topology-based and geographical-based routing protocol parameters to ensure QoS parameters in VANET. The former uses the network topology to make routing decisions, while the latter uses the location information of vehicles.  We will first provide an overview of VANET and QoS parameters. Then, we will delve into the key parameters of topology-based and geographical-based routing protocols and how they affect QoS. We will also survey and review the existing routing protocols and parameter values used in these protocols. The findings of this research paper will provide insights into the effective management of QoS parameters in VANET and contribute to the development of more efficient routing protocols

Optimization of Intelligent Transportation System using Biologically-Inspired Vehicular Ad hoc Networks for Achieve the Desired Performance

Many innovations made possible by the Intelligent Transportation System (ITS), such as media apps, encrypted financial transactions, and effective traffic management, rely heavily on vehicular ad hoc networks (VANETs). Using bio-inspired methodologies, This study looks back at the past and forward to the future to examine all of the routing challenges in VANETs, whether they are associated with a chain of related routing tasks or are aimed at a group of distinct approaches to routing. The high node mobility and unpredictable vehicle distribution (on the road) lead to major issues for VANETs, including the design of a network's physical architecture and unstable connections. VANET's provision of reliable and appropriate vehicular contact in situations requiring good service is crucial. As a result, effective means of navigation are desperately needed in VANET. Hence, in this paper, we examine the Bio-Inspired vehicular ad hoc networks (Bio-VANETs), wherein, should a suggested algorithmic network fail at any given node or vehicle, the remaining vehicles may be able to take over the task of relaying the data to the necessary nodes to achieve the desired performance. Route lifetime increases, and connection failures are decreased when the shortest way is selected using the fewest possible hops over highly connected links. In addition, the received signal intensity fluctuations due to vehicle density and speed are assessed. Packet Delivery Ratio, Optimal Performance, Accuracy and Efficiency of Bio-VANET are discussed and simulated against other methods that are existing models

Ethnobotanical investigations among tribes in Madurai District of Tamil Nadu (India)

BACKGROUND: An ethnobotanical survey was carried out to collect information on the use of medicinal plants in Southern Western Ghats of India (Madurai district, Tamil Nadu). Information presented in this paper was gathered from the paliyar tribes using an integrated approach of botanical collections, group discussions and interviews with questionnaires in the years 1998 – 1999. The informants interviewed were 12 among whom 4 were tribal practitioners. RESULTS: A total of 60 ethnomedicinal plant species distributed in 32 families are documented in this study. The medicinal plants used by paliyars are listed with Latin name, family, local name, parts used, mode of preparation and medicinal uses. Generally, fresh part of the plant was used for the preparation of medicine. CONCLUSION: We observed that the documented ethnomedicinal plants were mostly used to cure skin diseases, poison bites, stomachache and nervous disorders. The results of this study showed that these tribal people still depend on medicinal plants in Madurai district forest areas

Detection and Removal of Noise from Images using Improved Median Filter

Noise is any unwanted component in an image. It is important to eliminate noise in the images before some subsequent processing, such as edge detection, image segmentation and object recognition. This work mainly concentrates on automatic detection and efficient removal of impulse (salt and pepper) noise. For automatic detection of impulse noise, a method based on probability density function is proposed. The basic idea of automatic detection is that the difference between the probabilities of black and white pixels will be small. After detecting the presence of impulse noise in an image, we have to remove that noise. For the removal of impulse noise a new efficient impulse noise removal method (Modified SDROM filter) is proposed. The Modified SDROM consists of two parts 1) Impulse detector and 2) Filter. The results show that this method has higher performance than other methods in terms of PSNR values and SSIM-Index values

Photometry of the solar corona of March 7, 1970

Isophotes obtained by equidensitometry techniques from four exposures of the March 7, 1970 corona are used for derivation of intensity distributions along the equator, poles, streamers and dark 'gaps' in the visible corona. The distributions differ from the van de Hulst curves for a maximum corona. The Kodaikanal measures agree well with the NRL measures of the outer corona made from a rocket coronagraph and together provide data from 1.2R⊙ to 8.0R⊙ along the solar equator. Radial intensity gradients for different position angles and the Ludendorff parameters obtained, characterize this corona as typical of the solar maximum

Vacuum ultraviolet photoabsorption of prime ice analogues of Pluto and Charon

Here we present the first Vacuum UltraViolet (VUV) photoabsorption spectra of ice analogues of Pluto and Charon ice mixtures. For Pluto the ice analogue is an icy mixture containing nitrogen (N2), carbon monoxide (CO), methane (CH4) and water (H2O) prepared with a 100:1:1:3 ratio, respectively. Photoabsorption of icy mixtures with and without H2O were recorded and no significant changes in the spectra due to presence of H2O were observed. For Charon a VUV photoabsorption spectra of an ice analogue containing ammonia (NH3) and H2O prepared with a 1:1 ratio was recorded, a spectrum of ammonium hydroxide (NH4OH) was also recorded. These spectra may help to interpret the P-Alice data from New Horizons