On long-wavelength magnetic anomalies over Indian region

A data set composed of vector magnetic measurements obtained by MAGSAT and very accurate altitude determinations made using Sun sensors and star cameras was used to obtain data for very quiet days over the Indian region at 10 S to 40 N and 60 E to 110 E in an effort to determine the validity of quantitative estimates made from aeromagnetic data obtained by removing the core field. To further account for the external effects, the ring current contributions estimated using both X and Z variations were subtracted from the observed values. Before this, the core contribution was eliminated through a spherical harmonic expansion with terms up to N=13. Analysis of the residual measurements using Fast Fourier techniques indicates that the anomalies contain substantial power for wavelengths of about 1500 kms. Because the ring current effect has a spatial structure of this dimension over India, efforts are being made to exactly eliminate these two interfering effects from the data

Simulated Model Studies on the Beneficiation of Calcareous Phosphate Ore

The main sources of rock phosphate are located in Rajasthan, Mussoorie (U.P.), Singhbhum (Bihar), Purulia (W.B.) etc. Phosphate rocks generally occur as calcitic, siliceous and ferruginous in nature. Rajasthan and Muss-oorie rocks are calcareous (CaO 40-50%). Hence to enrich the phosphate in the rock from average 16-20% to above 30% P205 two possible alternatives to beneficiate this ore

Birefringence analysis of multilayer leaky cladding optical fibre

We analyse a multilayer leaky cladding (MLC) fibre using the finite element method and study the effect of the MLC on the bending loss and birefringence of two types of structures: (i) a circular core large-mode-area structure and (ii) an elliptical-small-core structure. In a large-mode-area structure, we verify that the multilayer leaky cladding strongly discriminates against higher order modes to achieve single-mode operation, the fibre shows negligible birefringence, and the bending loss of the fibre is low for bending radii larger than 10 cm. In the elliptical-small-core structure we show that the MLC reduces the birefringence of the fibre. This prevents the structure from becoming birefringent in case of any departures from circular geometry. The study should be useful in the designs of MLC fibres for various applications including high power amplifiers, gain flattening of fibre amplifiers and dispersion compensation.Comment: 18 page

Co-axial dual-core resonant leaky fibre for optical amplifiers

We present a co-axial dual-core resonant leaky optical fibre design, in which the outer core is made highly leaky. A suitable choice of parameters can enable us to resonantly couple power from the inner core to the outer core. In a large-core fibre, such a resonant coupling can considerably increase the differential leakage loss between the fundamental and the higher order modes and can result in effective single-mode operation. In a small-core single-mode fibre, such a coupling can lead to sharp increase in the wavelength dependent leakage loss near the resonant wavelength and can be utilized for the suppression of amplified spontaneous emission and thereby gain equalization of an optical amplifier. We study the propagation characteristics of the fibre using the transfer matrix method and present an example of each, the large-mode-area design for high power amplifiers and the wavelength tunable leakage loss design for inherent gain equalization of optical amplifiers.Comment: 6 page

Solid State Chemistry of Thallous Molybdate

849-85

Clinicoetiological profile of neonatal seizures in a tertiary care hospital

Background: Seizure is one of the most frequently observed clinical sign in neonatal period and may be the only sign of a central nervous system disorder. Its recognition is of paramount importance and a newborn with seizures is in a true medical emergency requiring prompt intervention. Objective: To determine the clinical and etiological profile of seizures among neonates admitted to neonatal unit in a tertiary care hospital. Materials and Methods: It was a prospective, observational, hospital-based study conducted over a period of 1 year (December 2014-November 2015). Nearly, 63 babies either admitted with neonatal seizures or who developed seizures after admission were studied to find the clinical and etiological profile. Detailed history including gestational age, mode of delivery, birth events, Apgar scores and antenatal problems, age of onset, and frequency of seizures was also noted. Seizures were classified on the basis of detailed description by pediatric resident on duty in a predesigned pro forma. Informed written consent of parents was taken before enrolling a baby in study. Results: Sepsis was the most common cause of neonatal seizures (64.9%), followed by birth asphyxia, i.e., hypoxic ischemic encephalopathy (HIE) (48.3%). Hypoglycemia was seen in 21.6% and hypocalcemia in 18.3% cases. Subtle seizures were the most common type of seizures seen in 65% babies, followed by tonic (31.6%), myoclonic (16.6%%), and clonic (6.67%) type. Subtle seizures were commonly seen in cases of HIE. Conclusion: The recognition of clinicoetiology of neonatal seizures is often helpful with respect to prognosis and treatment. The most common etiology for neonatal seizure is sepsis. Onset of seizures during first 3 days of life has significant correlation with HIE as etiology. Subtle seizures are the most common type of clinical seizures, which is difficult to identify; therefore, careful observation of at risk newborns is necessary

Transcranial Magnetic Stimulation-coil design with improved focality

Transcranial Magnetic Stimulation (TMS) is a technique for neuromodulation that can be used as a non-invasive therapy for various neurological disorders. In TMS, a time varying magnetic field generated from an electromagnetic coilplaced on the scalp is used to induce an electric field inside the brain. TMS coilgeometry plays an important role in determining the focality and depth of penetration of the induced electric field responsible for stimulation. Clinicians and basic scientists are interested in stimulating a localized area of the brain,while minimizing the stimulation of surrounding neural networks. In this paper, a novel coil has been proposed, namely Quadruple Butterfly Coil (QBC) with an improved focality over the commercial Figure-8 coil. Finite element simulations were conducted with both the QBC and the conventional Figure-8 coil. The two coil’s stimulation profiles were assessed with 50 anatomically realistic MRIderived head models. The coils were positioned on the vertex and the scalp over the dorsolateral prefrontal cortex to stimulate the brain. Computer modeling of the coils has been done to determine the parameters of interest-volume of stimulation, maximum electric field, location of maximum electric field and area of stimulation across all 50 head models for both coils

Prospective randomised comparison of femoral transfix versus endobutton with constant tibial fixation in hamstring tendon ACL reconstruction: a preliminary study

Background: The purpose of this study is to evaluate clinico radiological outcome of hamstring tendon ACL reconstruction using femoral Transfixation and Endobutton with identical Tibial fixation.Methods: A Prospective randomized clinical outcome study was done from January 2002 to June 2008, a total of 132 patients with quadruple hamstring ACL reconstruction using a femoral fixation group A Endobutton (n=68; median age=27.4) and group B with Transfix (n=64; median age=26.1) and identical Tibial fixation with Biointerference screw and bone staple were studied. Patients in each group had a clinical and radiological assessment at <3, 3-12, 12-24 and >24 months after surgery.Results: The mean Lysholm Knee score has improved significantly with time within these groups but no difference on comparison between groups. Ninety percent of all patients had functionally normal or near normal International Knee Documentation Committee (IKDC) knee ligament ratings. IKDC Subjective Knee evaluation mean score has progressively increased significantly from pre op values of 37.58 and 36.55 to about 74.51 and 75.85 in group A and group B respectively. The tibial and femoral tunnels also showed widening of about 9.64% and 7.79% in group A as compared to 7.71% and 7.27% in group B at >24 months follow-up, which was statistically insignificant. MRI done in limited patients showed good graft incorporation in both groups.Conclusions: So keeping the tibial graft fixation constant, the two different femoral fixation methods, Endobutton and transfixation have not influenced in the clinical outcome in this short term preliminary study. But long term follow up of these is necessary to evaluate the significance of tunnel widening and its final outcome

Rotate-and-Press: A Non-Visual Alternative to Point-and-Click

Most computer applications manifest visually rich and dense graphical user interfaces (GUIs) that are primarily tailored for an easy-and-efficient sighted interaction using a combination of two default input modalities, namely the keyboard and the mouse/touchpad. However, blind screen-reader users predominantly rely only on keyboard, and therefore struggle to interact with these applications, since it is both arduous and tedious to perform the visual \u27point-and-click\u27 tasks such as accessing the various application commands/features using just keyboard shortcuts supported by screen readers. In this paper, we investigate the suitability of a \u27rotate-and-press\u27 input modality as an effective non-visual substitute for the visual mouse to easily interact with computer applications, with specific focus on word processing applications serving as the representative case study. In this regard, we designed and developed bTunes, an add-on for Microsoft Word that customizes an off-the-shelf Dial input device such that it serves as a surrogate mouse for blind screen-reader users to quickly access various application commands and features using a set of simple rotate and press gestures supported by the Dial. Therefore, with bTunes, blind users too can now enjoy the benefits of two input modalities, as their sighted counterparts. A user study with 15 blind participants revealed that bTunes significantly reduced both the time and number of user actions for doing representative tasks in a word processing application, by as much as 65.1% and 36.09% respectively. The participants also stated that they did not face any issues switching between keyboard and Dial, and furthermore gave a high usability rating (84.66 avg. SUS score) for bTunes