Surprising simplicity in the modeling of dynamic granular intrusion

Granular intrusions, such as dynamic impact or wheel locomotion, are complex multiphase phenomena where the grains exhibit solid-like and fluid-like characteristics together with an ejected gas-like phase. Despite decades of modeling efforts, a unified description of the physics in such intrusions is as yet unknown. Here we show that a continuum model based on the simple notions of frictional flow and tension-free separation describes complex granular intrusions near free surfaces. This model captures dynamics in a variety of experiments including wheel locomotion, plate intrusions, and running legged robots. The model reveals that three effects (a static contribution and two dynamic ones) primarily give rise to intrusion forces in such scenarios. Identification of these effects enables the development of a further reduced-order technique (Dynamic Resistive Force Theory) for rapid modeling of granular locomotion of arbitrarily shaped intruders. The continuum-motivated strategy we propose for identifying physical mechanisms and corresponding reduced-order relations has potential use for a variety of other materials.Comment: 41 pages including supplementary document, 10 figures, and 8 vide

Tubercular dactylitis with deformity ipsilateral involvement of hand and foot in an adult: a case report

Tubercular dactylitis is a rare entity and usually involves bones of hands and feet, involvement of feet is less common. Here we report case of 18 years old female with neglected tubercular involvement of her left thumb and left great toe of foot with hallux varus deformity. Her diagnosis was delayed as she did not seek any healthcare advice for a long time and also lack of suspicion of entity. This entity which should be kept in mind when making differential diagnosis that can be treated conservatively when diagnosed early

Geochemistry and geohydrology of the Deccan volcanic rocks of Akole Taluka, Ahmednagar District, Maharashtra State, India.

The study area is bounded between longitudes 73\sp\circ\ 45\sp\prime E and 73\sp\circ\ 55\sp\prime E and latitudes 19\sp\circ\ 30\sp\primeN and 19\sp\circ\ 40\sp\primeN. It comprises three tribal villages in the Deccan Trap region of the Western Ghats, Maharashtra State, India. The bedrock is massive tholeiitic basalt of the Thakurvadi Formation. The petrography and geochemistry of the 47 samples collected mainly from hand-dug wells and blastholes were examined in order to determine their petrogenesis and to establish the geochemical stratigraphy of the Thakurvadi Formation. Petrographically the rocks are porphyritic to microphyric and aphyric, fine- to medium-grained massive basalts. They are commonly amygdaloidal filled with zeolites. Two suites were defined on the basis of phenocryst content: Suite No 1 with olivine, plagioclase, clinopyroxene assemblages, and Suite No 2 with olivine, plagioclase, clinopyroxene, and magnetite assemblages. Chemically the rocks are altered and show variation in compostion, with increases in K\sb2O content and relatively small increases in Na\sb2O content. An attempt has been made to establish a stratigraphic sequence for 40 rock samples within the middle Thakurvadi Formation. In order to achieve uniformity of approach with the previous investigations, the samples were arranged in the increasing order to their elevation, and were plotted against the trace element chemistry and petrographic features at the interval of 20-30 m. The results of the present study indicate no physiographic breaks in the rock chemistry. Marker horizon(s) such as Giant PIagioclase Basalts (2-5 cm) are not present; hence no distinct boundary or intra-formational sub-divisions were recognised. This suggests that the study area probably belongs to flows that show petrographically two distinct suites, but shows an overlap in chemistry. Because lavas pinch out and dip, it is difficult to correlate the chemical types in the study area with that of the reference section. (Abstract shortened by UMI.)Dept. of Geology and Geological Engineering. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1994 .A345. Source: Masters Abstracts International, Volume: 34-02, page: 0682. Advisers: Frank Simpson; T. E. Smith. Thesis (M.Sc.)--University of Windsor (Canada), 1995

BioN∅T: A searchable database of biomedical negated sentences

<p>Abstract</p> <p>Background</p> <p>Negated biomedical events are often ignored by text-mining applications; however, such events carry scientific significance. We report on the development of BioN∅T, a database of negated sentences that can be used to extract such negated events.</p> <p>Description</p> <p>Currently BioN∅T incorporates ≈32 million negated sentences, extracted from over 336 million biomedical sentences from three resources: ≈2 million full-text biomedical articles in Elsevier and the PubMed Central, as well as ≈20 million abstracts in PubMed. We evaluated BioN∅T on three important genetic disorders: autism, Alzheimer's disease and Parkinson's disease, and found that BioN∅T is able to capture negated events that may be ignored by experts.</p> <p>Conclusions</p> <p>The BioN∅T database can be a useful resource for biomedical researchers. BioN∅T is freely available at <url>http://bionot.askhermes.org/.</url> In future work, we will develop semantic web related technologies to enrich BioN∅T.</p

Mechanistic framework for reduced-order models in soft materials: Application to three-dimensional granular intrusion

Soft materials often display complex behaviors that transition through apparent solid- and fluid-like regimes. While a growing number of microscale simulation methods exist for these materials, reduced-order models that encapsulate the global-scale physics are often desired to predict how external bodies interact with soft media, as occurs in diverse situations from impact and penetration problems to locomotion over natural terrains. This work proposes a systematic program to develop three-dimensional reduced-order models for soft materials from a fundamental basis using continuum symmetries and rheological principles. In particular, we derive a reduced-order technique for modeling intrusion in granular media which we term three-dimensional Resistive Force Theory (3D-RFT), which is capable of accurately and quickly predicting the resistive stress distribution on arbitrary-shaped intruding bodies. Aided by a continuum description of the granular medium, a comprehensive set of spatial symmetry constraints, and a limited amount of reference data, we develop a self-consistent and accurate 3D-RFT. We verify the model capabilities in a wide range of cases and show it can be quickly recalibrated to different media and intruder surface types. The premises leading to 3D-RFT anticipate application to other soft materials with strongly hyperlocalized intrusion behavior.Comment: 12 pages, 7 figures, 1 SI document (12 pages, 8 figures, and 4 tables

Primary arthroplasty as an option for surgical treatment of unstable intertrochanteric fracture femur in elderly patients: a retrospective study

Background: An unstable intertrochanteric fracture in osteoporotic elderly patients presents a very challenging problem to the surgeons. This category of patients if kept in bed for long tends to have many complications like deep vein thrombosis, pneumonia, bed sores, etc. Surgeon’s worldwide face difficulty in getting a good anatomical reduction and do not allow early mobility to these patients because of risk of loss of reduction and implant cut out. The purpose of our study is to study the usefulness of arthroplasty in these patients in terms of better functional outcomes and no increase in complication rates.Methods: It was a retrospective study involving 25 patients (17 females, 8 males) with mean age of 76±2.3 years having intertrochanteric femur fractures (AO type A 2.2 and above) with osteoporosis operated upon with bipolar hemiarthroplasty at IQ City Medical College and NM Hospital between January 2015 and January 2017.Results: All the patients were followed up for a period of 1 year. We had a mean operative time of 75 min (range 55-125 min) with an average blood loss of 450 ml. 4 of our patients required postoperative blood transfusion. All patients walked on 2nd postoperative day. We had a mean Harris hip score of 82 and mean VAS of 1 at the end of 1 year.Conclusions: Hemiarthroplasty done in cases of unstable intertrochanteric femur fractures in elderly patients with osteoporotic bones allows early weight bearing thus improves the final functional outcomes. Further randomized trials are required before deriving any conclusions

Assessment of lead toxicity on locomotion and growth in a nematode Caenorhabditis elegans

Due to anthropogenic activities and natural abundance, lead exposure is a common phenomenon. Neurotoxic and genotoxic effects of lead are widely known. Recent studies have suggested that lead exposure can affect young generation and transfer to the progeny thus posing a great threat for future generation. The present study was focused on lead toxicity in terms of locomotion and growth of Caenorhabditis elegans (N2 wild type) at three sub-lethal doses (3µM, 15 µM and 30 µM) of Pb (NO3)2 for 24 hours (sub-chronic exposure). Caenorhabditis elegans is a nematode with an established eco- toxicity marker model organism, due to its short life cycle and ease to monitor. After lead&nbsp; exposure, significant toxic manifestations were observed in locomotion of the nematode in terms of omega bends (+350% for 30 µM exposure dose, p&lt;0.001), reversals (-26.98%, -49% and -66.35% for 3 µM, 15 µM and 30 µM exposure doses respectively, p&lt;0.001), turn counts (-38.66%, -62.61% and -81.93% for 3 µM, 15 µM and 30 µM exposure doses respectively, p&lt;0.001 ) and peristaltic speed alterations (+97.83%, +225.92% and +454.63% for 3 µM, 15 µM and 30 µM exposure doses respectively, p&lt;0.001). Successive reduction in the body length at lower doses shows remarkable toxic alterations in nematodes. The obtained data may be useful to extrapolate the effects of lead exposure on humans, as many of the similar pathways and cellular processes affected by Pb in humans are also present in C. elegans

Mergers and Acquisitions in Tea Industry: A Case Study

ABSTRACT This dissertation is aimed at finding motives and assessing the consequences of mergers and acquisitions, taking Tata's acquisition of Tetley into consideration. It overviews a vast amount of theoretical literature on mergers and acquisitions and presents empirical literature findings on company'ss post-merger financial performance. Case study section of the dissertation considers the history of Tata Tea Ltd. for engaging in M&A activities and measures the consequences of the activity by applying accounting and empirical financial approaches. Quantitative data is obtained from both online and published resources. The findings from the study are: Mergers and acquisitions contribute to increase in net sales revenue. Their impact on market share can either be neutral or positive. Quantitative data is taken from company'ss annual reports, business research companies' archives and financial websites. The findings from the study are mergers and acquisition's can either have a positive or negative impact on financial performance