Energy management in multi stage evaporator through a steady and dynamic state analysis

Increasing energy demand, high cost of energy and global warming issues across the globe require energy-intensive industries, such as paper mills to improve energy efficiency. Multi-stage evaporators used to concentrate the black liquor in such mills form its most energy consuming unit and require a strong understanding of steady and unsteady state behavior to ensure energy savings. The modeling of nonlinear heptads’ effect system yielded a set of complex nonlinear algebraic and differential equations that are analyzed using Interior-point method and state space representation. Dynamic response of product concentration and system vapor temperatures along with system stability and controllability have been explored by disturbing the flow rate, concentration and temperature of feed, and fresh steam flow rate. Simulations predict that steam flow rate, feed flow rate and its concentration invariably are major controlling factors (in decreasing order) of vapor temperature and product concentration. The interactive behavior between different effects translates into slower responses of the effects with increasing separation from disturbance source. This steady state and transient study opens many new explanations to this relatively less explored area and helps to propose and implement industrial PID controllers to reduce steam consumption and control product quality.     

Analysis of the Temperature Dependence of Diode Ideality Factor in InGaN-Based UV-A Light-Emitting Diode

Semiconductors - The temperature dependence of diode ideality factor in InGaN-based UV-A light-emitting diode has been investigated using the current–voltage characteristics at different...     

Nitrate and fluoride contamination in groundwater of an intensively managed agroecosystem: A functional relationship

A study was conducted to assess the potential of nitrate-nitrogen (NO₃-N) and fluoride (F) contamination in drinking groundwater as a function of lithology, soil characteristics and agricultural activities in an intensively cultivated district in India. Two hundred and fifty two groundwater samples were collected at different depths from various types of wells and analyzed for pH, electrical conductivity (EC), NO₃-N load and F content. Database on lithology, soil properties, predominant cropping systems, fertilizer and pesticide uses were also recorded for the district. The NO₃-N load in groundwater samples were low ranging from 0.12 to 6.58 μg mL^− 1 with only 8.7% of them contained greater than 3.0 μg mL^− 1 well below the 10 μg mL^− 1, the threshold limit fixed by WHO for drinking purpose. Samples from the habitational areas showed higher NO₃-N content over the agricultural fields. The content decreased with increasing depth of wells (r = − 0.25, P ≤ 0.01) and increased with increasing rate of nitrogenous fertilizer application (r = 0.90, P ≤ 0.01) and was higher in areas where shallow- rather than deep-rooted crops (r = − 0.28, P = ≤ 0.01, with average root depth) are grown. The NO₃-N load also decreased with increasing bulk density (r = − 0.73, P ≤ 0.01) and clay content (r = − 0.51, P ≤ 0.01) but increased with increasing hydraulic conductivity (r = 0.68, P ≤ 0.01), organic C (r = 0.78, P ≤ 0.01) and potential plant available N (r = 0.82, P ≤ 0.01) of soils. Fluoride content in groundwater was also low (0.02 to 1.15 μg mL^− 1) with only 4.0% of them exceeding 1.0 μg mL^− 1 posing a potential threat of fluorosis. On average, its content varied little spatially and along depth of sampling aquifers indicating little occurrence of F containing rocks/minerals in the geology of the district. The content showed a significant positive correlation (r = 0.234, P = ≤ 0.01) with the amount of phosphatic fertilizer (single super phosphate) used for agriculture. Results thus indicated that the groundwater of the study area is presently safe for drinking purpose but some anthropogenic activities associated with intensive cultivation had a positive influence on its loading with NO₃-N and F.     

Directional filter bank-based fingerprint image quality

Pattern Analysis and Applications - Fingerprint image quality ensures that only the high-quality fingerprints containing a good amount of features are used for verification. Fingerprint matching...     

Effect of microwave pretreatment on the dyeing behaviour of polyester fabric

Polyester fabric (filament by filament) was pretreated in a microwave oven in the presence of solvents and subsequently dyed with commercial disperse dyes [Dispersol Red C‐B (CI Disperse Red 91) and Dispersol Blue B‐G (CI Disperse Blue 26)] at different temperatures and for different durations of time. It was observed that the solvent interaction with the polyester could be enhanced by using microwave heating. Solvent molecules interact rapidly, not only with the surface of the fibre but also with the interior parts. Scanning electron microscope results showed that structural modifications take place, which produce surface roughness and voids. This enhances the dye uptake by threefold in comparison to conventional methods.     

Study of solvent dependence of Methyl Red and C60 based organic photovoltaic devices

In this work, the effect of solvent on the photovoltaic properties of Methyl Red (MR) dye and C₆₀ based device has been reported. It can be assumed for a dye based photovoltaic device that there is an effect of solvent on the film morphology which controls the charge transport mechanism. To observe this effect of solvent on the film morphology two different solvents namely chlorobenzene and toluene are used to prepare the solutions of MR and C₆₀. The devices made with chlorobenzene and toluene solvents are termed as chlorobenzene cell and toluene cell respectively. For each solvent different devices are prepared by varying the weight ratio of MR and C_60. These cells are characterized through different photovoltaic measurements. Experimental data reveal that the photovoltaic response is higher in case of chlorobenzene cell than that of the toluene cell. The power conversion efficiency for toluene cell for a particular concentration of MR:C₆₀ is 0.781 × 10^− 7 whereas for chlorobenzene cell it is 1.026 × 10^− 5. Maximum V_oc and J_sc obtained for toluene cell are 19.5 mV and 33.73 ?nA/cm² whereas for chlorobenzene cell these are 720 mV and 158.0 nA/cm² respectively. Scanning electron microscope images indicate the difference in nano-morphology and cluster sizes between the cells. The cluster size is quite large in case of toluene cell with comparison to chlorobenzene cell. From the transient photocurrent measurement it is observed that the charge transport process is quite faster in chlorobenzene cell which prevents excess recombination resulting in a higher efficiency in chlorobenzene cell.     

Extraction and characterization of pectin from pomelo peel and its impact on nutritional properties of carrot jam during storage

Pectin was extracted using 0.1 N HCl at 90 °C for 120 min at pH 1.5 and 2.0 from pomelo peel and characterized in this study. Influence of various concentrations of extracted pomelo peel pectin on physicochemical, bioactive compounds, color, and sensory attributes of carrot jam during storage was also studied. Pectin extracted at pH 2.0 had higher ash content, equivalent weight, and total anhydrouronic acid content than that extracted at pH 1.0. Extracted pomelo peel pectin was categorized as high‐methoxyl pectin based on the degree of esterification. The β‐carotene and total phenol content were increased in jam after 90 days of storage. Ascorbic acid content decreased with increasing storage period. Jam prepared using commercial pectin had higher ΔE values than jam prepared using pomelo peel pectin. Physico‐chemical properties were influenced by pectin concentrations and storage time. Overall acceptability was similar for all samples on the basis of sensory evaluation. The results showed that pomelo peel might be used as a rich source of pectin and pomelo peel pectin could be used as an alternative to commercial pectins for carrot jam preparation.

Practical applications

Pectin is one of the main ingredients for jam and jelly making. Citrus fruits are main sources of pectin. Usually pomelo peels are discarded as waste materials. However, it could be a good source of pectin. In this article, pectin was extracted from pomelo peel and its application was observed as carrot jam during storage. Therefore, it can be concluded that extraction of pectin from pomelo peel might be used as an alternative to commercial pectin for carrot jam preparation.     

Increased capacitation of buffalo sperm by heparin as confirmed by electron microscopy and in vitro fertilization

Capacitation of buffalo sperm was evaluated by induced acrosome reaction (AR) upon the exposure of 10 mM Ca2+. Culture of sperm for 8 hr in BO medium supplemented with 10 micrograms/ml heparin significantly (P < 0.01) increased the percentage of AR and confirmed by transmission electron microscopy. Vesiculization of outer acrosomal membrane and plasma membrane was observed significantly higher (P < 0.01) following 8 hr of sperm culture with heparin. Culture of sperm with heparin also increased rate of fertilization of in vitro matured oocytes and their subsequent development up to morula/blastocyst stage (P < 0.01). The study demonstrates that capacitation of buffalo sperm by heparin required at least 8 hr exposure of sperm to heparin for maximum acrosome reaction.     

Efficient max-margin multi-label classification with applications to zero-shot learning

The goal in multi-label classification is to tag a data point with the subset of relevant labels from a pre-specified set. Given a set of L labels, a data point can be tagged with any of the 2 ^L possible subsets. The main challenge therefore lies in optimising over this exponentially large label space subject to label correlations. Our objective, in this paper, is to design efficient algorithms for multi-label classification when the labels are densely correlated. In particular, we are interested in the zero-shot learning scenario where the label correlations on the training set might be significantly different from those on the test set. We propose a max-margin formulation where we model prior label correlations but do not incorporate pairwise label interaction terms in the prediction function. We show that the problem complexity can be reduced from exponential to linear while modelling dense pairwise prior label correlations. By incorporating relevant correlation priors we can handle mismatches between the training and test set statistics. Our proposed formulation generalises the effective 1-vs-All method and we provide a principled interpretation of the 1-vs-All technique. We develop efficient optimisation algorithms for our proposed formulation. We adapt the Sequential Minimal Optimisation (SMO) algorithm to multi-label classification and show that, with some book-keeping, we can reduce the training time from being super-quadratic to almost linear in the number of labels. Furthermore, by effectively re-utilizing the kernel cache and jointly optimising over all variables, we can be orders of magnitude faster than the competing state-of-the-art algorithms. We also design a specialised algorithm for linear kernels based on dual co-ordinate ascent with shrinkage that lets us effortlessly train on a million points with a hundred labels.