886 research outputs found
Boosting Higgs CP properties via VH Production at the Large Hadron Collider
We consider ZH and WH production at the Large Hadron Collider, where the
Higgs decays to a bb pair. We use jet substructure techniques to reconstruct
the Higgs boson and construct angular observables involving leptonic decay
products of the vector bosons. These efficiently discriminate between the
tensor structure of the HVV vertex expected in the Standard Model and that
arising from possible new physics, as quantified by higher dimensional
operators. This can then be used to examine the CP nature of the Higgs as well
as CP mixing effects in the HZZ and HWW vertices separately.Comment: 5 pages, 3 figures. v2: two references added and typo correcte
Quest for new materials: Inorganic chemistry plays a crucial role
There is an endless quest for new materials to meet the demands of advancing technology. Thus, we need new magnetic and metallic/semiconducting materials for spintronics, new low-loss dielectrics for telecommunication, new multi-ferroic materials that combine both ferroelectricity and ferromagnetism for memory devices, new piezoelectrics that do not contain lead, new lithium containing solids for application as cathode/anode/electrolyte in lithium batteries, hydrogen storage materials for mobile/transport applications and catalyst materials that can convert, for example, methane to higher hydrocarbons, and the list is endless! Fortunately for us, chemistry - inorganic chemistry in particular - plays a crucial role in this quest. Most of the functional materials mentioned above are inorganic non-molecular solids, while much of the conventional inorganic chemistry deals with isolated molecules or molecular solids. Even so, the basic concepts that we learn in inorganic chemistry, for example, acidity/basicity, oxidation/reduction (potentials), crystal field theory, low spin-high spin/inner sphere-outer sphere complexes, role of d-electrons in transition metal chemistry, electron-transfer reactions, coordination geometries around metal atoms, Jahn-Teller distortion, metal-metal bonds, cation-anion (metal-nonmetal) redox competition in the stabilization of oxidation states - all find crucial application in the design and synthesis of inorganic solids possessing technologically important properties. An attempt has been made here to illustrate the role of inorganic chemistry in this endeavour, drawing examples from the literature as well as from the research work of my group
Jet substructure and probes of CP violation in Vh production
We analyse the hVV (V = W, Z) vertex in a model independent way using Vh
production. To that end, we consider possible corrections to the Standard Model
Higgs Lagrangian, in the form of higher dimensional operators which parametrise
the effects of new physics. In our analysis, we pay special attention to linear
observables that can be used to probe CP violation in the same. By considering
the associated production of a Higgs boson with a vector boson (W or Z), we use
jet substructure methods to define angular observables which are sensitive to
new physics effects, including an asymmetry which is linearly sensitive to the
presence of CP odd effects. We demonstrate how to use these observables to
place bounds on the presence of higher dimensional operators, and quantify
these statements using a log likelihood analysis. Our approach allows one to
probe separately the hZZ and hWW vertices, involving arbitrary combinations of
BSM operators, at the Large Hadron Collider.Comment: 37 pages, 17 figures; v3 matches published versio
Sensors in Unmanned Robotic Vehicle
Unmanned tracked vehicles are developed for deployment in dangerous zones that are notsafe for human existence. These vehicles are to be fitted with various sensors for safe manoeuvre.Wide range of sensors for vehicle control, vision, and navigation are employed. The main purposeof the sensors is to infer the intended parameter precisely for further utilisation. Software isinseparable part of the sensors and plays major role in scaling, noise reduction, and fusion.Sensor fusion is normally adapted to enhance the decision-making. Vehicle location andorientation can be sensed through global positioning system, accelerometer, gyroscope, andcompass. The unmanned vehicle can be navigated with the help of CCD camera, radar, lidar,ultrasonic sensor, piezoelectric sensor, microphone, etc. Proximity sensors like capacitive andRF proximity detectors can detect obstacles in close vicinity. This paper presents an overviewof sensors normally deployed in unmanned tracked vehicles
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Extracting Visual information From Text: using Captions to Label Human Faces in Newspaper Photographs
There are many situations where linguistic and pictorial data are jointly presented to communicate information. A computer model for synthesising information from the two sources requires an initial interpretation of both the text and the picture followed by consolidation of information. The problem of performing general-purpose vision(without apriori knowledge) would make this a nearly impossible task. However, in some situations, the text describes salient aspects of the picture. In such situations, it is possible to extract visual information from the text, resulting in a relational graph describing the structure of the accompanying picture. This graph can then be used by a computer vision system to guide the interpretation of the picture. This paper discusses an application whereby information obtained from parsing a caption of a newspaper photograph is used to identify human faces in the photograph. Heuristics are described for extracting information from the caption which contributes to the hypothesised structure of the picture. The top-down processing of the image using this information is discussed
Barriers to Health among IDPs in Kabul, Afghanistan: a qualitative study
Background: Forced displacement is a significant problem for regions experiencing prolonged humanitarian crises due to armed conflict. Afghanistan, having experienced over four decades of conflict, has an estimated 1.2 million internally displaced persons (IDPs), a majority of which are concentrated in urban centers. IDPs have limited resources and face challenges accessing health services through traditional channels, leading to a disproportionate burden of morbidity and mortality. Health care facilities created for and existing within IDP camps also face numerous challenges. We aim to understand the structural factors that negatively impact health and the specific barriers to healthcare access for IDPs using qualitative methods.
Methods: A brief qualitative study was done to assess the barriers to health faced by IDPs and to understand the experience of providers caring for IDPs. We conducted open-ended interviews using a semi-structured interview guide across three IDP camps in Kabul, Afghanistan between May and June 2017. Participants were interviewed in focus groups, interviewing a total of 37 IDP ag 18 and older. In addition, two former health care providers were interviewed. We used grounded theory to code interviews using a priori and emergent coding, from which several themes and sub-themes emerged. Two independent readers coded the data and discrepancies were resolved by consensus.
Results: Human security, water access, limited livelihood and employment, poor housing infrastructure and environmental factors significantly impacted IDP health. Closure of clinics within the camps caused substantial limitations to healthcare service access. Accessing existing health care infrastructure was limited by cost, distance, discrimination, and limited access to medication and vaccinations, particularly for children. Key informant interviews identified healthcare funding and vaccination delivery to be priority problems. Across all focus groups and key informant interviews, there appeared to be a solid and trusted patient-provider relationship.
Conclusion
Structural factors that negatively impact health coupled with new barriers to healthcare access for IDPs in Kabul are a source of serious concern. Our study identified structural factors that exacerbate poor health and new challenges to healthcare access resulting from the discontinuation of in-camp health services. Further research should be done on the barriers and facilitators of transition from emergency humanitarian response to long-term care for IDPs, as well as on the ability of local health systems to absorb vulnerable populations after humanitarian crises
Hybrid Evolutionary Computing Assisted Irregular-Shaped Patch Antenna Design for Wide Band Applications
A novel optimization concept for modeling irregular-shaped patch antenna with high bandwidth and efficient radiation attributes is proposed in this paper, along with the ability to accomplish the design at a reduced computational and cost burden. A revolutionary computing perception is established with Gravitational Search Algorithm (GSA) and Quantum Based Delta Particle Swarm Optimization (QPSO), now known as GSA-QPSO. The suggested model employed the GSA-QPSO algorithm strategically interfaced with a high-frequency structure simulator (HFSS) software through a Microsoft Visual Basic script to enhance irregular-shaped antenna design while maintaining wide bandwidth with suitable radiation efficiency over the target bandwidth region. The optimally designed microstrip patch antenna is fabricated on an FR-4 substrate with a surface area of 30×30×1.6 mm 3 . The evaluated outcome shows 96 % supreme radiation efficacy at 2.4 GHz whereas overall effectiveness is above 84% over the entire frequency range, with a nearly omnidirectional radiation pattern. In terms of impedance bandwidth, the suggested antenna offers 126.6 % over the operational frequency range from 2.34 GHz to 10.44 GHz. Fabrication and measurement results are also used to validate the simulated results. It exhibits the proficiency of the offered antenna design to be used for real-world wideband (WB) communication drives
Elastocapillary driven assembly of particles at free-standing smectic-A films
Colloidal particles at complex fluid interfaces and within films assemble to
form ordered structures with high degrees of symmetry via interactions that
include capillarity, elasticity, and other fields like electrostatic charge.
Here we study microparticle interactions within free-standing smectic-A films,
in which the elasticity arising from the director field distortion and
capillary interactions arising from interface deformation compete to direct the
assembly of motile particles. New colloidal assemblies and patterns, ranging
from 1D chains to 2D aggregates, sensitive to the initial wetting conditions of
particles at the smectic film, are reported. This work paves the way to
exploiting LC interfaces as a means to direct spontaneously formed,
reconfigurable, and optically active materials.Comment: 8 pages, 6 figures. Supplementary Materials: 3 pages, 3 figure
The Origin of Nitrogen on Jupiter and Saturn from the N/N Ratio
The Texas Echelon cross Echelle Spectrograph (TEXES), mounted on NASA's
Infrared Telescope Facility (IRTF), was used to map mid-infrared ammonia
absorption features on both Jupiter and Saturn in February 2013. Ammonia is the
principle reservoir of nitrogen on the giant planets, and the ratio of
isotopologues (N/N) can reveal insights into the molecular
carrier (e.g., as N or NH) of nitrogen to the forming protoplanets, and
hence the source reservoirs from which these worlds accreted. We targeted two
spectral intervals (900 and 960 cm) that were relatively clear of
terrestrial atmospheric contamination and contained close features of
NH and NH, allowing us to derive the ratio from a single
spectrum without ambiguity due to radiometric calibration (the primary source
of uncertainty in this study). We present the first ground-based determination
of Jupiter's N/N ratio (in the range from to
), which is consistent with both previous space-based studies
and with the primordial value of the protosolar nebula. On Saturn, we present
the first upper limit on the N/N ratio of no larger than
for the 900-cm channel and a less stringent
requirement that the ratio be no larger than for the
960-cm channel ( confidence). Specifically, the data rule out
strong N-enrichments such as those observed in Titan's atmosphere and in
cometary nitrogen compounds. To the extent possible with ground-based
radiometric uncertainties, the saturnian and jovian N/N ratios
appear indistinguishable, implying that N-enriched ammonia ices could
not have been a substantial contributor to the bulk nitrogen inventory of
either planet, favouring the accretion of primordial N from the gas phase
or as low-temperature ices.Comment: 33 pages, 19 figures, manuscript accepted for publication in Icaru
Higgs Physics at the Large Hadron Collider
In this talk I will begin by summarising the importance of the Higgs physics
studies at the LHC. I will then give a short description of the pre-LHC
constraints on the Higgs mass and the theoretical predictions for the LHC along
with a discussion of the current experimental results, ending with prospects in
the near future at the LHC. In addition to the material covered in the
presented talk, I have included in the writeup, a critical appraisal of the
theoretical uncertainties in the Higgs cross-sections at the Tevatron as well
as a discussion of the recent experimental results from the LHC which have
become available since the time of the workshop.Comment: LateX, 12 figures, 15 pages, Presented at the XIth Workshop on High
Energy Physics Phenomenology, 2010, Ahmedabad, Indi
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