11,388 research outputs found
Polymer Dissolution Model: An Energy Adaptation Of The Critical Ionization Theory
The current scale of features size in the microelectronics industry has reached the point where molecular level interactions affect process fidelity and produce excursions from the continuum world like line edge roughness (LER). Here we present a 3D molecular level model based on the adaptation of the critical ionization (CI) theory using a fundamental interaction energy approach. The model asserts that it is the favorable interaction between the ionized part of the polymer and the developer solution which renders the polymer soluble. Dynamic Monte Carlo methods were used in the current model to study the polymer dissolution phenomenon. The surface ionization was captured by employing an electric double layer at the interface, and polymer motion was simulated using the Metropolis algorithm. The approximated interaction parameters, for different species in the system, were obtained experimentally and used to calibrate the simulated dissolution rate response to polymer molecular weight and developer concentration. The predicted response is in good agreement with experimental dissolution rate data. The simulation results support the premise of the CI theory and provide an insight into the CI model from a new prospective. This model may provide a means to study the contribution of development to LER and other related defects based on molecular level interactions between distinct components in the polymer and the developer.Chemical Engineerin
Experimental Evaluation and Performance of Window Air Conditioner by Using Pre-Cooled Air in Condenser
Reduction of energy consumption is a major concern in the vapor compression refrigeration cycle especially in the area with very hot weather conditions (about 50 ºC), where window-air conditioners are usually used to cool homes. Research programs in order to improve the performance of window-air-conditioners by enhancing heat transfer rate in the condenser. In this system air is cooled outside the window air conditioner, and this cold air is fed over the condenser tubes. After to this greater amount of heat rejected from refrigerant vapor and low condensation pressure is obtained, which in turn increase Coefficient of performance (COP) of air conditioner. Air is pre-cooled in a device, in which atmospheric air is directly contact with water which comes from top of the device in fine droplets. Due to contact between air-water, air is cooled and passes to air conditioner. Practical performance shows that, by this arrangement reduces power consumption and improving performance of air-conditioner
ARTYCUL: A Privacy-Preserving ML-Driven Framework to Determine the Popularity of a Cultural Exhibit on Display.
We present ARTYCUL (ARTifact popularitY for CULtural heritage), a machine learning(ML)-based framework that graphically represents the footfall around an artifact on display at a museum or a heritage site. The driving factor of this framework was the fact that the presence of security cameras has become universal, including at sites of cultural heritage. ARTYCUL used the video streams of closed-circuit televisions (CCTV) cameras installed in such premises to detect human figures, and their coordinates with respect to the camera frames were used to visualize the density of visitors around the specific display items. Such a framework that can display the popularity of artifacts would aid the curators towards a more optimal organization. Moreover, it could also help to gauge if a certain display item were neglected due to incorrect placement. While items of similar interest can be placed in vicinity of each other, an online recommendation system may also use the reputation of an artifact to catch the eye of the visitors. Artificial intelligence-based solutions are well suited for analysis of internet of things (IoT) traffic due to the inherent veracity and volatile nature of the transmissions. The work done for the development of ARTYCUL provided a deeper insight into the avenues for applications of IoT technology to the cultural heritage domain, and suitability of ML to process real-time data at a fast pace. While we also observed common issues that hinder the utilization of IoT in the cultural domain, the proposed framework was designed keeping in mind the same obstacles and a preference for backward compatibility
Pre-main sequence variable stars in young open cluster NGC 1893
We present results of multi-epoch (fourteen nights during 2007-2010) -band
photometry of the cluster NGC 1893 region to identify photometric variable
stars in the cluster. The study identified a total of 53 stars showing
photometric variability. The members associated with the region are identified
on the basis of spectral energy distribution, two colour diagram and
colour-magnitude diagram. The ages and masses of the majority of
pre-main-sequence sources are found to be 5 Myr and in the range 0.5
4, respectively. These pre-main-sequence
sources hence could be T Tauri stars. We also determined the physical
parameters like disk mass and accretion rate from the spectral energy
distribution of these T Tauri stars. The periods of majority of the T Tauri
stars range from 0.1 to 20 day. The brightness of Classical T Tauri stars is
found to vary with larger amplitude in comparison to Weak line T Tauri stars.
It is found that the amplitude decreases with increase in mass, which could be
due to the dispersal of disks of massive stars.Comment: 15pages, 16 figures and 5 tables, Accepted for publication in MNRA
Enzymatic synthesis of isopropyl myristate using immobilized lipase from Bacillus cereus MTCC 8372
A purified alkaline thermo-tolerant bacterial lipase from Bacillus cereus MTCC 8372 was immobilized on a Poly (MAc- co -DMA- cl -MBAm) hydrogel. The hydrogel showed approximately 94% binding capacity for lipase. The immobilized lipase (2.36 IU) was used to achieve esterification of myristic acid and isopropanol in n -heptane at 65 °C under continuous shaking. The myristic acid and isopropanol when used at a concentration of 100 mM each in n -heptane resulted in formation of isopropyl myristate (66.0 ± 0.3 mM) in 15 h. The reaction temperature below or higher than 65°C markedly reduced the formation of isopropyl myristate. Addition of a molecular sieve (3 Å × 1.5 mm) to the reaction mixture drastically reduced the ester formation. The hydrogel bound lipase when repetitively used to perform esterification under optimized conditions resulted in 38.0 ± 0.2 mM isopropyl myristate after the 3 rd cycle of esterification.<br /
Two Gallium data sets, spin flavour precession and KamLAND
We reexamine the possibility of a time modulation of the low energy solar
neutrino flux which is suggested by the average decrease of the Ga data in line
with our previous arguments. We perform two separate fits to the solar neutrino
data, one corresponding to 'high' and the other to 'low' Ga data, associated
with low and high solar activity respectively. We therefore consider an
alternative to the conventional solar+KamLAND fitting, which allows one to
explore the much wider range of the angle permitted by the
KamLAND fitting alone. We find a solution with parameters in which the 'high' and
the 'low' Ga rates lie far apart and are close to their central values and is
of comparable quality to the global best fit, where these rates lie much closer
to each other. This is an indication that the best fit in which all solar and
KamLAND data are used is not a good measure of the separation of the two Ga
data sets, as the information from the low energy neutrino modulation is
dissimulated in the wealth of data. Furthermore for the parameter set proposed
one obtains an equally good fit to the KamLAND energy spectrum and an even
better fit than the 'conventional' LMA one for the reactor antineutrino
survival probability as measured by KamLAND.Comment: V2: 15 pages, 3 eps figures, fit improved, final version to appear in
Journal of Physics
Skin pigmentation, a window to diagnose Alkaptonuria: a very rare entity
Alkaptonuria (AKU) or endogenous ochronosis is a very rare inborn error of tyrosine metabolism inherited by autosomal recessive mode. There is complete absence of homogentisic acid oxidase enzyme which results in accumulation of homogentisic acid in cartilaginous connective tissue thus produces ochronotic clinical manifestations. Here we reported a 36 year old woman with bluish pigmentation of pinnae, index fingers (lateral aspect), nails, teeth and sclera. Detailed clinical and investigative workup was done to diagnose patient. Skin biopsy showed changes of ochronosis and urine examination revealed detectable level of homogentisic acid. Classical ocular findings, ochronosis on clinical and HPE and positive urinary tests for homogentisic acid confirmed the diagnosis of alkaptonuria. The highlight of our case is that an asymptomatic patient was detected early by ochronosis prior to development of musculoskeletal or cardiac complications
Conjugatable water-soluble Pt(ii) and Pd(ii) porphyrin complexes: Novel nano- and molecular probes for optical oxygen tension measurement in tissue engineering
Measurement of oxygen tension in compressed collagen sheets was performed using matrix-embedded optical oxygen sensors based on platinum(II) and palladium(II) porphyrins supported on polyacrylamide nanoparticles. Bespoke, fully water-soluble, mono-functionalised Pt(II) and Pd(II) porphyrin complexes designed for conjugation under mild conditions were obtained using microwave-assisted metallation. The new sensors display a linear response (1/τ vs. O₂) to varying oxygen tension over a biologically relevant range (7.0 × 10⁻⁴ to 2.7 × 10⁻¹ mM) in aqueous solutions; a behaviour that is maintained following conjugation to polyacrylamide nanoparticles, and following embedding of the nanosensors in compressed collagen sheets, paving the way to innovative approaches for real-time resolution of oxygen gradients throughout 3D matrices useful for tissue regeneration
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