4,243 research outputs found
Foundation Performance of Very Old Structures
Withstanding the agents of destruction for several centuries, some of the structures in this world, exist as a testimony to the sound and perfected techniques of construction used in years that belong to the bygone past. Among the most famous are Taj Mahal and Qutb Minar, still standing in a magnificent and sound condition. One of the wonders of the world, Taj Mahal though built in seventeenth century still looks so fresh that the super-structure performance also speaks of the adequate and perfect foundation that must have been built for it. This paper deals with subsoil conditions at site, the type of foundation, its construction technique and its performance for a very long period for both Taj Mahal and Qutb Minar
Recommended from our members
A new, substituted palladacycle for ppm level Pd-catalyzed Suzuki-Miyaura cross couplings in water.
A newly engineered palladacycle that contains substituents on the biphenyl rings along with the ligand HandaPhos is especially well-matched to an aqueous micellar medium, enabling valued Suzuki-Miyaura couplings to be run not only in water under mild conditions, but at 300 ppm of Pd catalyst. This general methodology has been applied to several targets in the pharmaceutical area. Multiple recyclings of the aqueous reaction mixture involving both the same as well as different coupling partners is demonstrated. Low temperature microscopy (cryo-TEM) indicates the nature and size of the particles acting as nanoreactors. Importantly, given the low loadings of Pd invested per reaction, ICP-MS analyses of residual palladium in the products shows levels to be expected that are well within FDA allowable limits
Discovery of High-Latitude CO in a HI Supershell in NGC 5775
We report the discovery of very high latitude molecular gas in the edge-on
spiral galaxy, NGC 5775. Emission from both the J=1-0 and 2-1 lines of 12CO is
detected up to 4.8 kpc away from the mid-plane of the galaxy. NGC 5775 is known
to host a number of HI supershells. The association of the molecular gas
M(H2,F2) = 3.1x10^7 solar masses reported here with one of the HI supershells
(labeled F2) is clear, which suggests that molecular gas may have survived the
process which originally formed the supershell. Alternatively, part of the gas
could have been formed in situ at high latitude from shock-compression of
pre-existing HI gas. The CO J=2-1/J=1-0 line ratio of 0.34+-40% is
significantly lower than unity, which suggests that the gas is excited
subthermally, with gas density a few times 100 cubic cm. The molecular gas is
likely in the form of cloudlets which are confined by magnetic and cosmic rays
pressure. The potential energy of the gas at high latitude is found to be
2x10^56 ergs and the total (HI + H2) kinetic energy is 9x10^53 ergs. Based on
the energetics of the supershell, we suggest that most of the energy in the
supershell is in the form of potential energy and that the supershell is on the
verge of falling and returning the gas to the disk of the galaxy.Comment: Accept by ApJL, 4 pages, 3 ps figure
High sensitivity and multifunctional micro-Hall sensors fabricated using InAlSb/InAsSb/InAlSb heterostructures
Further diversification of Hall sensor technology requires development of materials with high electron mobility and an ultrathin conducting layer very close to the material's surface. Here, we describe the magnetoresistive properties of micro-Hall devices fabricated using InAlSb/InAsSb/InAlSb heterostructures where electrical conduction was confined to a 30 nm-InAsSb two-dimensional electron gas layer. The 300 K electron mobility and sheet carrier concentration were 36 500 cm(2) V-1 s(-1) and 2.5 x 10(11) cm(-2), respectively. The maximum current-related sensitivity was 2 750 V A(-1) T-1, which was about an order of magnitude greater than AlGaAs/InGaAs pseudomorphic heterostructures devices. Photolithography was used to fabricate 1 mu m x 1 mu m Hall probes, which were installed into a scanning Hall probe microscope and used to image the surface of a hard disk
SemanticFusion: Dense 3D Semantic Mapping with Convolutional Neural Networks
Ever more robust, accurate and detailed mapping using visual sensing has proven to be an enabling factor for mobile robots across a wide variety of applications. For the next level of robot intelligence and intuitive user interaction, maps need extend beyond geometry and appearence - they need to contain semantics. We address this challenge by combining Convolutional Neural Networks (CNNs) and a state of the art dense Simultaneous Localisation and Mapping (SLAM) system, ElasticFusion, which provides long-term dense correspondence between frames of indoor RGB-D video even during loopy scanning trajectories. These correspondences allow the CNN's semantic predictions from multiple view points to be probabilistically fused into a map. This not only produces a useful semantic 3D map, but we also show on the NYUv2 dataset that fusing multiple predictions leads to an improvement even in the 2D semantic labelling over baseline single frame predictions. We also show that for a smaller reconstruction dataset with larger variation in prediction viewpoint, the improvement over single frame segmentation increases. Our system is efficient enough to allow real-time interactive use at frame-rates of approximately 25Hz
The Effect of Cash Transfers and Household Vulnerability on Food Security in Zimbabwe.
We study the impact of the Zimbabwe Harmonized Social Cash Transfer (HSCT) on household food security after 12 months of implementation. We investigate determinants of food security as measured by a well-known food security scale – the Household Food Insecurity Access Scale (HFIAS) – and as measured by value of household food consumption composed of own-production, market purchases and gifts received. We find that several dimensions of household vulnerability correlate more strongly with the food security measure than with food consumption. Labor constraints, which is a key vulnerability criterion used by the HSCT to target households, is an important predictor of the food security score but not food consumption, and its effect on food security is even larger during the lean season. Impact analysis shows that the program has had statistically significant impacts on Food Security and Diet Diversity scores but null to low impacts on food consumption. However aggregate food consumption hides dynamic activity taking place within the household where the cash is used to obtain more food from the market and rely less on food received as gifts. The cash in turn gives beneficiaries greater choice in their food basket, which improves diet diversity
A cash plus program reduces youth exposure to physical violence in Zimbabwe
Violence against children and adolescents, a highly prevalent problem, is a clear violation of child rights and has detrimental effects on later life outcomes. Programs that alleviate poverty address a structural determinant of child vulnerability and can thereby reduce child abuse. This paper investigates whether the Government of Zimbabwe's Harmonized Social Cash Transfer (HSCT) Program, which combines cash transfers with complementary services, affects youth exposure to physical violence. The analysis uses data from a non-experimental impact evaluation and a difference-in-differences approach. Results show a 19-percentage point decline in the incidence of physical violence among youth four years into the program. HSCT-induced enhancements in beneficiary households’ purchasing capacity and food security, improvements in caregiver subjective well-being, and reductions in youth participation in economic work for pay could be mediating the program's effects on youth abuse. This paper adds to the relatively scarce evidence on the impacts of anti-poverty policies on young people's susceptibility to physical violence in developing countries
Reciprocating Reversible Front Wheel Drive Incorporated in a Trike
With growing time, there are upcoming new technologies related to driving mechanisms but indeed led to massive emissions and violation of nature laws. Oil consumption is going high and nearly half of the world oil consumption is through automotive sector. Thus there is need for some source, by which we can prevent our nature. This could be done via various methods. One such is- encouraging the use of hybrid trikes. Generally tricycles are less preferred by humans because they require more human effort, they cannot be reversed, doesn't provide the comfortability, rollover stability is less and are slow in speed.
Thus this segment aims at developing a reciprocating reversible drive mechanism in a three wheeler trike which has not been incorporated till now and brings out various advantages. Viewing into the context of INDIA, one cannot drive any vehicle without reversing, thus this mechanism allows a vehicle to be reversed and further, it also reduces the human effort required for the vehicle to move (initial torque increases). This hybrid vehicle allows, increasing the speed of vehicle and making it an all- wheel drive. Further suspension system is incorporated such that the full frame is suspended and provides at-par comfortability and excellent rollover stability to the vehicle. Other advantages include low maintenance cost, always in running condition, cheap in price and one of its kinds when it comes to eco -friendly vehicle
A Comparative Study of the Parker Instability under Three Models of the Galactic Gravity
To examine how non-uniform nature of the Galactic gravity might affect length
and time scales of the Parker instability, we took three models of gravity,
uniform, linear and realistic ones. To make comparisons of the three gravity
models on a common basis, we first fixed the ratio of magnetic pressure to gas
pressure at = 0.25, that of cosmic-ray pressure at = 0.4, and
the rms velocity of interstellar clouds at = 6.4 km s, and then
adjusted parameters of the gravity models in such a way that the resulting
density scale heights for the three models may all have the same value of 160
pc. Performing linear stability analyses onto equilibrium states under the
three models with the typical ISM conditions, we calculate the maximum growth
rate and corresponding length scale for each of the gravity models. Under the
uniform gravity the Parker instability has the growth time of 1.2
years and the length scale of 1.6 kpc for symmetric mode. Under the realistic
gravity it grows in 1.8 years for both symmetric and
antisymmetric modes, and develops density condensations at intervals of 400 pc
for the symmetric mode and 200 pc for the antisymmetric one. A simple change of
the gravity model has thus reduced the growth time by almost an order of
magnitude and its length scale by factors of four to eight. These results
suggest that an onset of the Parker instability in the ISM may not necessarily
be confined to the regions of high and .Comment: Accepted for publication in ApJ, using aaspp4.sty, 18 text pages with
9 figure
- …