Topology and Polarisation of Subbeams Associated With Pulsar B0943+10's `Drifting'-Subpulse Emission: II. Analysis of Gauribidanur 35-MHz Observations

In the previous paper of this series Deshpande & Rankin (2001) reported results regarding subpulse-drift phenomenon in pulsar B0943+10 at 430 MHz and 111 MHz. This study has led to the identification of a stable system of subbeams circulating around the magnetic axis of this star. Here, we present a single-pulse analysis of our observations of this pulsar at 35 MHz. The fluctuation properties seen at this low frequency, as well as our independent estimates of the number of subbeams required and their circulation time, agree remarkably well with the reported behavior at higher frequencies. We use the `cartographic'-transform mapping technique developed in Paper-I to study the emission pattern in the polar region of this pulsar. The significance of our results in the context of radio emission mechanisms is also discussed.Comment: 6 pages, 7 figures (2 color figs), MNRAS, 326 (4), 1249-1254 (2001

Fluctuation Properties and Polar Emission Mapping of Pulsar B0834+06 at Decameter Wavelengths

Recent results regarding subpulse-drift in pulsar B0943+10 have led to the identification of a stable system of sub-beams circulating around the magnetic axis of the star. Here, we present single-pulse analysis of pulsar B0834+06 at 35 MHz, using observations from the Gauribidanur Radio Telescope. Certain signatures in the fluctuation spectra and correlations allow estimation of the circulation time and drift direction of the underlying emission pattern responsible for the observed modulation. We use the `cartographic transform' mapping technique to study the properties of the polar emission pattern. These properties are compared with those for the other known case of B0943+10, and the implications are discussed.Comment: (v3: minor changes); 9 pages, 6 figures (11 ps files); To appear in MNRA

BRIGE: Translating Robotic Technology for Inclusive Fitness: An Innovative Robotic Rowing Exoskeleton (RRE) Development Project

Intellectual Merit: The opportunities for inclusion in fitness activity for disabled individuals, particularly those with severe disabilities, are extremely limited due to intrinsic, environmental, and social factors. This BRIGE project focuses on advancing robotic technology as a strategy to promote fitness opportunities for a range of individuals with disabilities. This project will 1) design, test, and build a prototype robotic device called Robotic Rowing Exoskeleton (RRE) that will augment movement, coordination, and strength in the activity of rowing; 2) yield a complete dynamics model of rowing biomechanics and parameter determination via human subject data; 3) provide a model system through which biomechanics and parameter determination using human subject data can be translated into precise robotic-assisted movement; 4) integrate electromyography and robotics to create a prototype that will be responsive to individual user needs; and 5) advance the development of an ongoing research program in robotic devices for improved quality of life. Broader Impacts: This project will be used as the foundation for the CIDER (Creating Investigator Diversity in Engineering Research) model with five major components. First, diverse students for whom the research agenda is personally relevant and compelling will be recruited to participate in all phases of the program. Second, each of the student researchers will engage in outreach in schools and a summer camp program for middle and high school students to perpetuate ongoing recruitment of diverse students into engineering research careers. Third, a video of RRE, its development, and its use will be made for on-site and virtual dissemination nationwide. Fourth, we will continue an ongoing program which hosts robotics demos for middle school and high school students, especially, women, to encourage them to pursue a career in Engineering. Finally, the model will be formalized and evaluated so that it can be expanded to encourage the involvement of other underrepresented groups in engineering

Differential Spiral Joint Mechanism for Coupled Variable Stiffness Actuation

In this study, we present the Differential Spiral Joint (DSJ) mechanism for variable stiffness actuation in tendon-driven robots. The DSJ mechanism semi-decouples the modulation of position and mechanical stiffness, allowing independent trajectory tracking in different parameter space. Past studies show that increasing the mechanical stiffness achieves the wider range of renderable stiffness, whereas decreasing the mechanical stiffness improves the quality of actuator decoupling and shock absorbance. Therefore, it is often useful to modulate the mechanical stiffness to balance the required level of stiffness and safety. In addition, the DSJ mechanism offers a compact form factor, which is suitable for applications where the size and weight are important. The performance of the DSJ mechanism in various areas is validated through a set of experiments

Experiments and simulations of the interaction of high velocity granular slugs with structures

Shallow buried landmine explosions cause the ejection of a high velocity granular spray that impinges on structures. An understanding of the flow pattern of the ejected soil and its interaction with the target is needed for the development of protective systems. Here, we consider an idealized problem of a granular slug impinging on a structure to gain a basic understanding of the so-called fluid–structure interaction between the flowing granular medium and the impacted structure. This interaction is investigated both numerically using a coupled discrete particle – finite element method and laboratory scale experiments. Experiments and simulations are reported to investigate the effects of (i) granular properties such as interparticle stiffness, friction etc.; (ii) inclination of target relative to the oncoming slug; and (iii) friction between the target and particles; on the granular flow and the momentum transfer from the granular slug to the target. The findings are used to motivate how protective structures can be improved to mitigate the blast from landmine explosions

Comparison of the endotracheal cuff inflation techniques and its postoperative laryngotracheal morbidity: an observational study

Background: Endotracheal tubes cuffs are used to prevent gas leak and also pulmonary aspiration in mechanically ventilated patients. The commonly employed intubation techniques are the use of inflation to a constant pressure (25 cm H2O), sealing pressure and estimation of the cuff pressure by finger palpation. However, the use of the cuff inflation volumes may cause tracheal morbidity. The aim of the present study was to compare the effective tracheal seal and the incidence of post-intubation airway complications between the three techniques.Methods: 90 patients under N2O free general endotracheal anaesthesia were included in the study. They were randomly allotted into three groups consisting of 30 in each. After induction of anesthesia, endotracheal tubes size 7.0 mm for female and 8.5 mm for male were used. Constant pressure group (n=30), the cuff was inflated to a pressure of 25 cm H2O; sealing group (n=30), the cuff was inflated to prevent air leaks at airway pressure of 20 cm H2O and finger group (n=30), the cuff was inflated using finger estimation. Manometric cuff pressure and volume of air required to inflate the cuff, incidence of sore throat, hoarseness and dysphagia were tested.Results: Significant differences was not observed between the three groups in case of demographic data, ASA grading, endotracheal tube size used, number of attempts to place the endotracheal tubes, duration of intubation between the three groups. On the other hand, the cuff pressure, volume of air to fill the cuff and the incidence of sore throat was significantly higher in the finger group compared to other two groups (p ≤0.05). The incidence of dysphagia and hoarseness was also higher in finger palpitation group but the difference is insignificant.Conclusions: In cases of N2O free anesthesia, sealing cuff pressure is an easy and safe alternative technique compared to other two techniques, regarding effectiveness and low incidence of tracheal morbidities

Acute MI in a stented patient following snake bite-possibility of stent thrombosis – A case report

AbstractAcute myocardial infarction following snake bite is rare with few reported cases in literature. A 60-year-old male underwent uneventful stenting to a critical stenosis in left anterior descending coronary artery in June 2012. A month later, he presented to the local hospital with history of snake bite. During admission he developed chest pain with ST-segment elevation in anterior leads consistent with stent thrombosis. He was successfully thrombolysed and his coronary angiogram 5 days later revealed patent stent with TIMI III flow and no evidence of thrombus

Identification of Moisture Content in Cotton Bale by Microwave Imaging

Understanding of cotton quality is important in order to properly identify the moisture content .Measurement of moisture is difficult particularly at harvest and through the gin, because of the influence these processes have different fibre quality. Dry cotton can be harvested cleanly and efficiently but may suffer undue damage in the gin. On the other hand harvesting and ginning wet cotton leads to significant issues in processing and quality. A number of methods are used to measure moisture in seed cotton, lint and fuzzy seed, each has its varying advantages. A moisture variation of the bales that is not monitored from the outside of the bale. This research examines a new microwave imaging technique to view the internal moisture variations of cotton bale. Tests on the developed imaging sensor showed the ability to resolve small structures of parameters, against a low standard background, that were less than 1 cm in width. The accuracy of the sensing structure was also shown to provide the ability to accurately determine parameter standards. A preliminary test of the imaging capabilities on a wet commercial bale showed the technique was able to accurately image and determines the location of the wet layer within the bale

Investigating the robustness of a learning-based method for quantitative phase retrieval from propagation-based x-ray phase contrast measurements under laboratory conditions

Quantitative phase retrieval (QPR) in propagation-based x-ray phase contrast imaging of heterogeneous and structurally complicated objects is challenging under laboratory conditions due to partial spatial coherence and polychromaticity. A learning-based method (LBM) provides a non-linear approach to this problem while not being constrained by restrictive assumptions about object properties and beam coherence. In this work, a LBM was assessed for its applicability under practical scenarios by evaluating its robustness and generalizability under typical experimental variations. Towards this end, an end-to-end LBM was employed for QPR under laboratory conditions and its robustness was investigated across various system and object conditions. The robustness of the method was tested via varying propagation distances and its generalizability with respect to object structure and experimental data was also tested. Although the LBM was stable under the studied variations, its successful deployment was found to be affected by choices pertaining to data pre-processing, network training considerations and system modeling. To our knowledge, we demonstrated for the first time, the potential applicability of an end-to-end learning-based quantitative phase retrieval method, trained on simulated data, to experimental propagation-based x-ray phase contrast measurements acquired under laboratory conditions. We considered conditions of polychromaticity, partial spatial coherence, and high noise levels, typical to laboratory conditions. This work further explored the robustness of this method to practical variations in propagation distances and object structure with the goal of assessing its potential for experimental use. Such an exploration of any LBM (irrespective of its network architecture) before practical deployment provides an understanding of its potential behavior under experimental settings.Comment: Under review as a journal submission. Early version with partial results has been accepted for poster presentation at SPIE-MI 202