Chemical pretreatments and partial dehydration of ash gourd (Benincasa hispida) pieces for preservation of its quality attributes

Ash gourd (Benincasa hispida) is a commonly consumed vegetable in Asian subcontinent. Cut ash gourd pieces undergo severe decay within two days probably due to physical, biochemical and microbiological activities. Ash gourd pieces were chemically pretreated with sodium salt of ethylene diamine tetra acetic acid (sodium EDTA), calcium chloride (CaCl₂), citric acid and potassium metabisulphite (KMS) and dehydrated up to 30 percent moisture with an aim to extend its shelf life. Storage study of these samples was done with respect to texture, colour, bacterial content and water holding capacity. Shelf life was extended from two days to one month. Pretreatment using a combination of 1 mM EDTA, 2.5 percent KMS, 0.5 percent citric acid and 2.5 percent CaCl₂ and partial dehydration to 30 percent moisture found to be a good method in preservation of cut ash gourd pieces.     

On asymptotically efficient solutions for a class of supervisorycontrol problems

We consider restricted sequences of forbidden-string and forbidden-state problems and show the limiting problem instance defined by a sequence has a solution if and only if each problem instance in the sequence has a solution. Furthermore, the supervisor that enforces the desired behavior in the limiting problem instance also enforces the desired behavior in each problem instance in the sequence. In essence, the storage requirement for supervisory control of each instance is bounded above by that of the limiting problem instance. In addition, if the limiting problem instance is available, a similar observation can be made regarding the complexity of supervisory control. This observation coupled with recent results on the solvability of the supervisory control problem involving certain classes of nonregular behaviors and finite-representations of infinite-state systems is suggested as an effective procedure to combat the computational and storage issues in supervisory control. We conclude with an incomplete list of future research directions     

Estimating Fatigue Life of Bridge Components Using Measured Strains

The design fatigue life of a bridge component is based on the stress spectrum the component experiences and the fatigue durability. Changes in traffic patterns, volume, and any degradation of structural components can influence the fatigue life of the bridge. A fatigue life evaluation reflecting the actual conditions has value to bridge owners. Procedures are outlined in the AASHTO Guide Specifications for Fatigue Evaluation of Existing Steel Bridges to estimate the remaining fatigue life of bridges using the measured strain data under actual vehicular traffic. This paper presents the methodology with an actual case study of Patroon Island Bridge. The Patroon Island Bridge consists of ten spans. Spans 3 through 9 are considered the main spans and consist of steel trusses and concrete decks. Spans 1, 2, and 10 are considered approach spans and consist of plate girders. The overall bridge length is 1,795 feet. Strain data from critical structural members were used to estimate the remaining fatigue life of selected bridge components. The results indicate that most of the identified critical details have an infinite remaining safe fatigue life and others have a substantial fatigue life. Cracked floor beams were not addressed in this analysis, but have been recommended for retrofitting or replacement.     

Rating requirements of the unified power quality conditioner to integrate the fixedspeed induction generator-type wind generation to the grid

The ability of wind generation to remain connected to the grid in the event of system faults and dynamic reactive power compensation are two aspects of grid integration, which have received particular attention. The wind driven, fixed-speed induction generator (FSIG) on its own fails to fulfil these requirements of grid integration. The application of a unified power quality conditioner (UPQC) to overcome the grid integration problems of the FSIG is investigated. The role of the UPQC in enhancing the fault ride-through capability of the generator is also investigated under both full and partial terminal voltage restoration. A realistic estimation of the rating requirements of UPQC for this type of application is carried out. A general principle is presented to choose the most practical and economical rating of the UPQC. The performance comparison of a UPQC and a static synchronous compensator to aid fault ride-through capability of a 2 MW FSIG under Irish grid code requirements has been carried out and the UPQC is found to be more economical in relation to device rating.     

Transition metal modified bulk BiFeO3 with improved magnetization and linear magneto-electric coupling

At present BiFeO₃ (BFO) is the most attractive and sole example, which possesses low magnetization value, high leakage current and low polarization in ceramic form. Single-phase room temperature multiferroics are rare in nature. This paper deals with the improved magnetic and observed linear magneto-electric coupling in Co and Sm co-doped BiFeO₃ ceramics synthesized by sol-gel process at low temperature ∼600 °C. As synthesized Bi_0.9Sm_0.10Fe_0.95Co_0.05O₃ (BSFCO) showed high impurities phases (20%) over wide range of calcination temperatures. Impurity phases reduced drastically from 20% to 5% after leaching with nitric acid. However the electrical and the magnetic properties were almost the same for both phases. Well-defined magnetic hysteresis with high magnetic moment was found at room temperature. Ferroelectric polarization studies demonstrated similar values and shape as reported in literature for the pure bulk BFO. Linear magneto-electric (ME) coupling and weak ME coefficient (α) ∼ 0.6 e−10 s m⁻¹ were observed in the co-doped BFO. The origin of the strong ferromagnetic property in our samples may be due to the presence of rare earth and transition metal ions at the lattice sites of BFO or due to impurity phase, since we have not seen any change in magnetization with reduction of impurity phase the later effect is more unlikely.     

Studies on optimization of parameters for dewatering of ground calcite-rich ore

This paper deals with filtration of very-fine size ground brecciated calcitic limestone ore slurry using flocculant chemicals. Screening of flocculants was carried out using capillary suction time (CST). Optimization of the neutral slurry filtration behaviour was carried out using a commercial non-ionic type polyacrylamide based synthetic flocculant. Response surface methodology and central composite rotatable design was used for model development and optimization of the filtration process. Critical filtration parameters such as applied vacuum, cake thickness and flocculant dosage were optimized. A correlation coefficient of 0.97 was obtained both for filtration rate and percent cake moisture. The analysis of variance of the determined model indicated that linear effects, interaction effects, quadratic effects, linear terms of all the three variables and some interaction among them are more significant for the filtration rate and cake moisture percent. The optimum filtration rate of 742 kg/(h m²) was obtained at the optimum conditions with cake moisture of 22.3%.     

Image transforms as a tool for the study of soil salinity and alkalinity dynamics

Principal components analysis (PCA), ratioing, image differencing and intensity-hue-saturation (IHS) transformation have been widely used in monitoring various natural resources and environmental hazards. In our study, the temporal behaviour of salt-affected soils in the Indo-Gangetic alluvial plains of Uttar Pradesh has been studied using Landsat MSS data for 1975 and 1992. Apart from routine digital classification of temporal MSS data using Guassian maximum likelihood algorithm, PCA, image differencing, and ratioing were also evaluated for their potential in bringing out temporal changes in salt-affected soils, if any. The results indicate that the third principle component, image differencing, and ratioing of the first two MSS bands for two periods have brought out substantial information associated with the temporal behaviour of saltaffected soils.     

Mapping and monitoring of degraded lands in part of Jaunpur district of Uttar Pradesh using temporal spaceborne multispectral data

Apart from soil erosion by wind and water, the major land degradation processes operating in irrigated commands in arid and semi-arid regions are waterlogging and subsequent salinization/alkalinization. Remote sensing data have been used successfully in studies of the spatial extent, magnitude and temporal behaviour of lands affected by such processes. In this work we interpreted Landsat Multispectral Scanner images acquired during 1975 and Landsat Thematic Mapper data acquired during 1993, in conjunction with ancillary information and adequate ground data, to derive information on the extent and spatial distribution of various degraded lands, namely salt-affected soils, waterlogged areas and eroded lands in part of the Jaunpur district of Uttar Pradesh. The results indicate a significant shrinkage in the spatial extent of salt-affected soils (of the order of 49.76%) over the period 1975 to 1993. A similar trend was observed in the temporal behaviour of waterlogged areas, but an increase (6.45%) was found in the spatial extent of eroded lands. The methodology employed and the observations made are described here in detail.