Design, construction and testing of the Communications Technology Satellite protection against spacecraft charging

Detailed discussions are presented of the measures taken on the Communications Technology Satellite (CTS or Hermes) which provide protection against the effects of spacecraft charging. These measures include: a comprehensive grounding philosophy and implementation; provision of command and data line transmitters and receivers for transient noise immunity; and a fairly restrictive EMI specification. Ground tests were made on materials and the impact of these tests on the CTS spacecraft is described. Hermes, launched on 17 January 1976 on a 2914 Delta vehicle, has successfully completed 10 months of operations. Anomalies observed are being assessed in relation to spacecraft charging, but no definite correlations have yet been established. A list of conclusions with regard to the CTS experience is given and recommendations for future spacecraft are also listed

Design and analysis considerations for deployment mechanisms in a space environment

On the second flight of the INTELSAT V spacecraft the time required for successful deployment of the north solar array was longer than originally predicted. The south solar array deployed as predicted. As a result of the difference in deployment times a series of experiments was conducted to locate the cause of the difference. Deployment rate sensitivity to hinge friction and temperature levels was investigated. A digital computer simulation of the deployment was created to evaluate the effects of parameter changes on deployment. Hinge design was optimized for nominal solar array deployment time for future INTELSAT V satellites. The nominal deployment times of both solar arrays on the third flight of INTELSAT V confirms the validity of the simulation and design optimization

Making inexpensive drugs for the treatment of Human African Trypanosomiasis

Neglected tropical diseases (NTDs) affect the world’s poorest population; mainly in Africa, Asia, and Latin America. According to the WHO, more than one billion people are affected by NTDs. The connection between these areas is the lack of proper sanitation, and the persistence of the diseases, trap the affected countries in the poverty and disease cycle. African sleeping sickness, a prevalent NTD, is a parasitic infection caused by two parasites from the Trypanosoma brucei species and is transmitted by the tsetse fly or congenitally. The disease is manifested by fever, severe headaches, irritability, extreme fatigue, swollen lymph nodes, and aching muscles and joints. When it reaches the central nervous system it can cause progressive confusion, personality changes, and other neurologic problems. The high-cost and limited number of the drugs contribute to the increase of the cases resulting in a great impact on global health. The goal of our research is to develop inexpensive and effective drugs using low-cost organic starting materials that target the T. brucei parasite. Our target compounds are Mannich bases containing an aromatic moiety. Previous, but limited, studies have shown that this class of compounds demonstrates promising results against T. brucei. Our one step synthesis involves the use of nitro-substituted acetophenones, formaldehyde, and a variety of amines to make Mannich bases under conventional heating and microwave conditions. By changing the nitro-acetophenones and the amines used in the reaction, we hope to develop a robust drug library we can use to screen against T. brucei

Cloud Computing for Effective Cyber Security Attack Detection in Smart Cities

An astute metropolis is an urbanized region that accumulates data through diverse numerical and experiential understanding. Cloud-connected Internet of Things (IoT) solutions have the potential to aid intelligent cities in collecting data from inhabitants, devices, residences, and alternative origins. The monitoring and administration of carrying systems, plug-in services, reserve managing, H2O resource schemes, excess managing, illegal finding, safety actions, ability, numeral collection, healthcare abilities, and extra openings all make use of the processing and analysis of this data. This study aims to improve the security of smart cities by detecting attacks using algorithms drawn from the UNSW-NB15 and CICIDS2017 datasets and to create advanced strategies for identifying and justifying cyber threats in the context of smart cities by leveraging real-world network traffic data from UNSW-NB15 and labelled attack actions from CICIDS2017. The research aims to underwrite the development of more effective intrusion detection systems tailored to the unique problems of safeguarding networked urban environments, hence improving the flexibility and safety of smart cities by estimating these datasets

Microbial decomposition of the floating weed Salvinia molesta Aublet in Cochin backwaters

From the live and decomposing S. molesta 13 strains of bacteria were isolated and the growth promoting effect of the weed extract in various concentrations in 5 selected strains of bacteria and a mixed culture was studied. Turbidity measurements gave maximum percentaae transmission in 5 % extract. Dry weight loss of dried weed in the laboratory was 20 and 25 % after to and 25 days of incubation respectively. Yield efficiency of 3 bacterial strains calculated for 48 hr was 20%. The results suggest the potential value of this primary source of organic material in the food web of Cocbin backwater

HypTrails: A Bayesian Approach for Comparing Hypotheses About Human Trails on the Web

When users interact with the Web today, they leave sequential digital trails on a massive scale. Examples of such human trails include Web navigation, sequences of online restaurant reviews, or online music play lists. Understanding the factors that drive the production of these trails can be useful for e.g., improving underlying network structures, predicting user clicks or enhancing recommendations. In this work, we present a general approach called HypTrails for comparing a set of hypotheses about human trails on the Web, where hypotheses represent beliefs about transitions between states. Our approach utilizes Markov chain models with Bayesian inference. The main idea is to incorporate hypotheses as informative Dirichlet priors and to leverage the sensitivity of Bayes factors on the prior for comparing hypotheses with each other. For eliciting Dirichlet priors from hypotheses, we present an adaption of the so-called (trial) roulette method. We demonstrate the general mechanics and applicability of HypTrails by performing experiments with (i) synthetic trails for which we control the mechanisms that have produced them and (ii) empirical trails stemming from different domains including website navigation, business reviews and online music played. Our work expands the repertoire of methods available for studying human trails on the Web.Comment: Published in the proceedings of WWW'1

Reconstructing 3D x-ray CT images of polymer gel dosimeters using the zero-scan method

In this study x-ray CT has been used to produce a 3D image of an irradiated PAGAT gel sample, with noise-reduction achieved using the ‘zero-scan’ method. The gel was repeatedly CT scanned and a linear fit to the varying Hounsfield unit of each pixel in the 3D volume was evaluated across the repeated scans, allowing a zero-scan extrapolation of the image to be obtained. To minimise heating of the CT scanner’s x-ray tube, this study used a large slice thickness (1 cm), to provide image slices across the irradiated region of the gel, and a relatively small number of CT scans (63), to extrapolate the zero-scan image. The resulting set of transverse images shows reduced noise compared to images from the initial CT scan of the gel, without being degraded by the additional radiation dose delivered to the gel during the repeated scanning. The full, 3D image of the gel has a low spatial resolution in the longitudinal direction, due to the selected scan parameters. Nonetheless, important features of the dose distribution are apparent in the 3D x-ray CT scan of the gel. The results of this study demonstrate that the zero-scan extrapolation method can be applied to the reconstruction of multiple x-ray CT slices, to provide useful 2D and 3D images of irradiated dosimetry gels

Time history of the magnetospheric cavity

Laboratory scale model simulation of effect of solar wind on magnetosphere by propelling plasma stream into dipole magnetic field - time history of magnetospheric cavit