Physical phenomena in containerless glass processing

Experiments were conducted on bubble migration in rotating liquid bodies contained in a sphere. Experiments were initiated on the migration of a drop in a slightly less dense continuous phase contained in a rotating sphere. A refined apparatus for the study of thermocapillar flow in a glass melt was built, and data were acquired on surface velocities in the melt. Similar data also were obtained from an ambient temperature fluid model. The data were analyzed and correlated with the aid of theory. Data were obtained on flow velocities in a pendant drop heated from above. The motion in this system was driven principally by thermocapillarity. An apparatus was designed for the study of volatilization from a glass melt

Nanoscale quantum dot infrared sensors with photonic crystal cavity

We report high performance infrared sensors that are based on intersubband transitions in nanoscale self-assembled quantum dots combined with a microcavity resonator made with a high-index-contrast two-dimensional photonic crystal. The addition of the photonic crystal cavity increases the photocurrent, conversion efficiency, and the signal to noise ratio (represented by the specific detectivity D*) by more than an order of magnitude. The conversion efficiency of the detector at Vb=–2.6 V increased from 7.5% for the control sample to 95% in the PhC detector. In principle, these photonic crystal resonators are technology agnostic and can be directly integrated into the manufacturing of present day infrared sensors using existing lithographic tools in the fabrication facility

Teleoperation control of Baxter robot using Kalman filter-based sensor fusion

Kalman filter has been successfully applied to fuse the motion capture data collected from Kinect sensor and a pair of MYO armbands to teleoperate a robot. A new strategy utilizing the vector approach has been developed to accomplish a specific motion capture task. The arm motion of the operator is captured by a Kinect sensor and programmed with Processing software. Two MYO armbands with the inertial measurement unit embedded are worn on the operator's arm, which is used to detect the upper arm motion of the human operator. This is utilized to recognize and to calculate the precise speed of the physical motion of the operator's arm. User Datagram Protocol is employed to send the human movement to a simulated Baxter robot arm for teleoperation. In order to obtain joint angles for human limb utilizing vector approach, RosPy and Python script programming has been utilized. A series of experiments have been conducted to test the performance of the proposed technique, which provides the basis for the teleoperation of simulated Baxter robot

Performance studies on millet processing machinery for tribal livelihood promotion

A Millet Processing Centre for processing of minor millets in a tribal village in Tamil Nadu, has been established with the following millet processing machinery viz., Destoner, Millet Mill, Grain Polisher, Pulveriser, Flour Sifter and Packaging Machinery for enhancement of tribal livelihood. Performance studies on the machinery for processing minor millets viz., little millet, foxtail millet and finger millet grown in the tribal area were carried out. Based on the performance evaluation, the output capacity of destoner cum cleaner was found to be 230 kg/h and 233 kg/h for little and foxtail millet respectively with a cleaning efficiency of 89 and 90% respectively for the above millets. The performance of millet mill revealed that the output capacity was 90-92 kg/h for little and foxtail millet with a dehulling efficiency of 86 and 87% respectively with small percentage of brokens (< 5 %). The capacity of grain polisher was 60-61 kg/h with a polishing efficiency of 85% & 86% respectively for little and foxtail millet. The pulveriser was evaluated for finger millet flour making whereby the output capacity of the machine was 75 kg/h with a milling efficiency of 90% respectively. The cost economics revealed that the tribal farmers could save 85% of the processing cost. The benefit cost ratio was found to be 2.05.The total profit to the tribal Society through Millet Processing Centre was Rs. 21,000/- during the first harvesting season of millets. The above studies have paved way for satisfactory functioning of the Millet Processing Centre in the tribal area

Development of Continuous Feed Equipment for Aloe Vera Whole Gel Extraction

971-979Continuous feed Aloe vera whole gel extraction equipment comprises of six major components, (a) Outer frame to hold functional components; (b) Conveyor belt; (c) Drive mechanism for gel extraction system; (d) Whole gel extraction mechanism; (e) Collection trays for extracted gel and rinds; (f) Motor. Leaf base and sharp spines of matured Aloe vera leaves are removed before feeding into equipment. Combination action of sliding bearing (4 numbers) mechanism and pressure springs (4 numbers) helps to adjust gap between pressure roller assembly and flatten curvature of Aloe vera leaves. Two high carbon steel blades one each, just above bottom set of rollers and just below top set of rollers, simultaneous peels off both top and bottom rind in a single pass. To obtain whole gel recovery of more than 98.13 ± 0.52 % and residual gel percentage of below 1.87 ± 0.27%, speed of the rollers was optimized at 100 rpm for three levels of leaves thickness (30 mm). Capacity of equipment is 215.00 ± 9.08 kg/h. Percentage saving in cost and time of operation is 55.56 and 70 %, respectively. Quality parameters of whole Aloe vera gel were at par with preferred hand filleting method of gel extraction. Equipment is suitable to be adopted as a rural technology specially in the Aloe vera catchment area

Tropical cyclone projections: changing climate threats for Pacific island defense installations

Potential changing climate threats in the tropical and subtropical North Pacific Ocean were assessed, using coupled ocean-atmosphere and atmosphere-only general circulation models, to explore their response to projected increasing greenhouse gas emissions. Tropical cyclone occurrence, described by frequency and intensity, near islands housing major U.S. defense installations was the primary focus. Four island regions-Guam and Kwajalein Atoll in the tropical northwestern Pacific, Okinawa in the subtropical northwestern Pacific, and Oahu in the tropical north-central Pacific-were considered, as they provide unique climate and geographical characteristics that either enhance or reduce the tropical cyclone risk. Guam experiences the most frequent and severe tropical cyclones, which often originate as weak systems close to the equator near Kwajalein and sometimes track far enough north to affect Okinawa, whereas intense storms are the least frequent around Oahu. From assessments of models that simulate well the tropical Pacific climate, it was determined that, with a projected warming climate, the number of tropical cyclones is likely to decrease for Guam and Kwajalein but remain about the same near Okinawa and Oahu; however, the maximum intensity of the strongest storms may increase in most regions. The likelihood of fewer but stronger storms will necessitate new localized assessments of the risk and vulnerabilities to tropical cyclones in the North Pacific

Statistical Adaptive Sensing by Detectors with Spectrally Overlapping Bands

It has recently been reported that by using a spectral-tuning algorithm, the photocurrents of multiple detectors with spectrally overlapping responsivities can be optimally combined to synthesize, within certain limits, the response of a detector with an arbitrary responsivity. However, it is known that the presence of noise in the photocurrent can degrade the performance of this algorithm significantly, depending on the choice of the responsivity spectrum to be synthesized. We generalize this algorithm to accommodate noise. The results are applied to quantum-dot mid-infrared detectors with bias-dependent spectral responses. Simulation and experiment are used to show the ability of the algorithm to reduce the adverse effect of noise on its spectral-tuning capability