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Despite the success of various enhancement techniques used in many bio-medical applications, edge-preservation-based image enhancement remains a limiting factor for image quality and thus the usefulness of these techniques. In this paper, a new enhancement technique combining the variational mode decomposition (VMD) with the Sobel gradient and equalization technique is proposed. The proposed algorithm first decomposes the image into various sub-modes based on their frequency. The low-frequency components are equalized using the conventional equalization technique, whereas the high-frequency components use a traditional filter. Finally, the edge of the original image is added to the processed image for quality assurance. The proposed algorithm has two advantages over the existing approaches by enhancing only the low-frequency components to extract the hidden artefacts and specifically de-noising the high-frequency component. This process not only enhances the contrast, but also preserves the brightness of the image. A comprehensive study was conducted on the experimental results of benchmark test images using different performance measure matrices to quantify the effectiveness of the approach. In terms of both subjective and objective evaluation, the reconstructed image is found to be more accurate and visually pleasing. It also outperforms the state-of-the-art image-fusion methods, especially in terms of PSNR, RMSE, mutual information, and structural similarity.

In the world of digital image processing, image denoising plays a vital role, where the primary objective was to distinguish between a clean and a noisy image. However, it was not a simple task. As a consequence of everyone's understanding of the practical challenge, a variety of methods have been presented during the last few years. Of those, wavelet transformer-based approaches were the most common. But wavelet-based methods have their own limitations in image processing applications like shift sensitivity, poor directionality, and lack of phase information, and they also face difficulties in defining the threshold parameters. As a result, this study provides an image de-noising approach based on Bi-dimensional Empirical Mode Decomposition (BEMD). This project's main purpose is to disintegrate noisy images based on their frequency and construct a hybrid algorithm that uses existing de-noising techniques. This approach decomposes the noisy picture into numerous IMFs with residue, which were subsequently filtered independently based on their specific properties. To quantify the success of the proposed technique, a comprehensive analysis of the experimental results of the benchmark test images was conducted using several performance measurement matrices. The reconstructed image was found to be more accurate and pleasant to the eye, outperforming state-of-the-art denoising approaches in terms of PSNR, MSE, and SSIM.

The Rhus semialata (Nagatenga) fruit is small, round in shape and less than one inch in size and the fruit of Baccaurea sapida (Leteku) is yellowish and velvety, 2–3 cm in diameter with leathery pericarp. The shelf life of the fruits Rhus semialata and Baccaurea sapida is 1–2 days and upto 7 days, respectively under room temperature. These fruits can be considered as super foods as the study reveals that the fruits are accumulated with well-balanced nutrients and health protective compounds such as minerals, vitamins and phytochemicals. The physical and quality characteristics (edible portion, juice content, pulp content, acidity, TSS, pH, pectin) of the fruits reveals that they are suitable for producing various value-added products like beverages, sauce, pickle, jelly, etc. According to these characteristics, Rhus semialata fruits can be considered for making squash, sauce, pickle and chutney. Baccaurea sapida fruits due to being highly juicy with less pulpy characteristics are more suitable for beverage making; even good wine can be produced from this fruit. These minor fruits could be made available throughout the year and to the areas far from their site of yield by minimizing their post-harvest losses by extending the shelf life by processing them to different value-added products.

Lifestyle and dietary factors play a major role in maintaining and regulating the concentration of 1, 25-dihydroxyvitamin D in the body. The study was conducted on 350 women (aged 18-45 years), considering the significance of vitamin D in the health of women of reproductive age. 1, 25-dihydroxyvitamin D concentration was assessed using enzyme immunoassay method and chemiluminescence. Dietary history was assessed through 24-hour recall method and a pre-tested food frequency questionnaire for vitamin D and calcium intake. Data on lifestyle practices, including sun exposure pattern was recorded using a pre-tested questionnaire. Results revealed that the 1, 25-dihydroxyvitamin D concentration of tobacco and alcohol consumers were 19.87±3.78 ng/ml and 19.67±5.43 ng/ml, respectively, which were much below the normal range for 1,25-dihydroxyvitamin D concentration (30 ng/ml). Data on dietary intake showed that 1, 25-dihydroxyvitamin D concentration of both non-vegetarian and non-vegetarian were much below the normal range (18.67±7.66 ng/ml and 19.93±5.31 ng/ml, respectively). Correlation analysis between vitamin D concentration and dietary intake of vitamin D and calcium revealed a significant positive association between the two (p

The present study has been undertaken to develop a ready to eat instant rice based meal from commonly consumed ingredients like joha rice (Oryza sativa L.), lentil (Lens culinaris), green gram dhal (Vigna radiata), sweet corn (Zea mays), carrot (Daucus carota L.), french beans (Phaseolus vulgaris), tomato (Solanum lycopersicum), broccoli (Brassica oleracea var. italica), cabbage (Brassica oleracea var. capitata), green pea (Pisum sativum), rice bran oil, spices and condiments. The ingredients were processed and mixed in varying proportions to prepare one base meal and other three formulations. Joha rice and rice bran oil were taken as 35g and 5ml respectively for the base meal and for each of three different formulations but the proportions and the other ingredients were adjusted and mixed in different proportions. Among all the formulations, Formulation III made with 35% rice, 12% lentil dhal, 14% green gram dhal was much preferred by the panellist during sensory evaluation and was subjected to further analysis. Henceforth, it is concluded that instant rice based meal prepared using Formulation III can be successfully utilized which is easy and fast to prepare besides being hygienic and convenient to eat.

Sweet potato (Ipomea batatus) based complementary food was formulated from locally available foods by using different processing technologies like tray drying, roasting and sprouting. Three supplements were developed from locally available least expensive food items. Three different formulations were prepared from black rice, green gram, sweet potato, sesame seed; pumpkin seed, groundnut by incorporating them in varied compositiuon and analysed for their nutrient and functional properties by following standard procedures. The moisture content of the sweet potato based complementary mix was 6.97%. The protein content of the complementary food blends are within the RDA values (13-14g) for infants as recommended by Nutrition Research Council (1989). Crude fat content was 2.29% followed by ash 2.74%, crude fibre 2.10%. The calcium and iron content of the complementary food was 530mg/100gm dry weight and 8.7 mg/100gm dry weight respectively. The bulk density of the sweet potato based complementary food mix was 0.71g/ml followed by water holding capacity 9.80g/100g. The viscosities of the formulation from 10%, 20% and 30% slurry concentration with spindle-4 ranged from 1.0±0.02-1.6±0.06 mPa.s, 12.2±0.16-12.4±0.21 mPa.s and 28.5±1.13-39.7±1.17 mPa.s respectively. The present study showed that the sweet potato based complementary food mix formulated from locally available food commodities (black rice, green gram, sesame seed, pumpkin seed and groundnut) met the nutritional needs of the children between 6 months to 2 years of age. Also, the present study established that the processing methods (sprouting) carried out had a positive influence on the nutritive values of the formulated diets.

The operation and control of the modern power system has become complex and difficult due to the incessant penetration of nonconventional energy sources integrated to the power grid and the structural variation of power system with continuing escalation of power demand in recent years. This entails the implementation of intelligent control strategy for satisfactory operation of the power system. Hence, a fractional order fuzzy proportional integral derivative (FOFPID) controller is suggested in this article for automatic generation control of two unequal area interconnected power system with diverse generating units such as thermal, hydro, diesel and wind power plants. The dynamic performance of the system is investigated by using proportional integral derivative (PID), fractional order PID (FOPID), fuzzy PID (FPID) and fractional order fuzzy PID (FOFPID) controllers separately. The parameters of these controllers are optimised by using ant lion optimiser algorithm with integral time absolute error as the objective function. The supremacy of the proposed controller is established by contrasting the results with FPID, FOPID and PID controllers. It is also observed that FPID controller gives superior result than PID and FOPID controllers. Further it is found that the result of FOPID controller is better than the integer order PID controller. Finally robustness analysis is performed to confirm the robustness of the proposed controller against parametric variations and random loading of the system.

Nutrition intervention is considered the cornerstone of treatment for all women with pregnancy complications. Educating pregnant women on proper consumption of nutrients and a healthier lifestyle will help promote a healthy pregnancy. The objectives of this study is to assess the impact of nutrition counselling on food adequacy of pregnancy induced hypertension (PIH) and gestational diabetes mellitus (GDM) patients and a 24 hour recall questionnaire was used to assess the food intake among patients. Twenty two PIH and GDM patients were selected and equally divided into two groups, i.e., experimental group and control group. Nutrition counseling was imparted for three months (experimental group) at 30 days interval. The mean daily intake in the experimental group for pulses had no significant change, while cereals, milk and milk products, meat, fish and poultry, fruits, green leafy vegetables and other vegetables was increased significantly and that of roots and tubers, fats and oils and sugar and jaggery decreased significantly. However, the control group had no significant change for pulses, cereals, milk and milk products, meat, fish and poultry, fruits, green leafy vegetables, other vegetables, roots and tubers and sugar and jaggery while a significant decrease was observed in the mean daily intake of fats and oils.

This paper describes various control strategies used for controlling the desired heading angle of the Autonomous under water vehicle(AUV). The control of AUV is a great challenge for the researchers due to the time varying and highly nonlinear effect of hydrodynamic forces. The presence of communication constraints and the external disturbances inside the fluid makes the design of control action of AUV more difficult. In these situation the adaptive controller techniques such as Model reference adaptive controller (MRAC) is more suitable. The proposed new adaptive controller Fuzzy Model Reference Adaptive Controller (FMRAC) technique is the combination of MRAC and Fuzzy logic which produces better transient performance. The heading controller is designed and their performance is examined through the MATLAB/SIMULINK. The time response characteristics of the proposed controller are compared with traditional MRAC and FUZZY. The FMRAC has the ability to produce the stable operation and more effectiveness for controlling the heading angle.

The present study reports the effect of sorbitan monopalmitate (SM) as a crystallization modifier on the physicochemical properties of mango butter (MB). The concentration of SM was varied in the range of 1 and 5 wt%. The addition of SM promoted the aggregation of globular MB crystals. The FTIR patterns did not show any significant changes when SM was added. XRD and DSC analyses confirmed the crystallization of MB crystals in stable β′ and β (V) polymorphic states. However, SM also introduced imperfections in the crystal lattices of MB. Among all formulations, M2 (SM; 1% w/w) possessed a mechanically stable network structure. The crystallization rate of MB was tailored by SM in a concentration-dependent manner. The solid content was highest in M4 (SM; 5% w/w) at 10 °C and 30 °C among all the oleogels. In gist, SM in manageable quantities can be utilized for preparing custom-tailored MB-based products.

In ophthalmological field, automated segmentation of vasculatures is an arduous job for the analysis and monitoring of eye threatening diseases like hypertension, diabetic retinopathy, and glaucoma. This paper presents an unsupervised technique for the extraction of vascular structures from ophthalmoscope images. At first from the ophthalmoscope images, extraction of green channel takes place and then the vessels are enhanced by the matched filter technique. Then gray level co-occurence matrix is used to extract the textural information of the image. Finally, the post-processing method is implemented to get the final segmented image. Evaluations are attended on the newly freely accessible IOSTAR dataset. The average accuracy of this proposed method implemented on the new dataset is 0.943.

A very crucial question in sparse approximation-based image compression is the choice of the dictionary. An effective dictionary can lead to excellent representation of an image with least number of dictionary atoms and lead to excellent image compression. The performance of block-based intra-image compression scheme depends on how well the residuals obtained from intra-prediction are encoded. Transform-based intra-compression method uses fixed DCT dictionary for encoding of prediction residuals. However, DCT dictionary is not suited for efficient encoding of prediction residuals with complex and non-periodic characteristics. This paper presents an algorithm to design an over-complete residual dictionary suitable for encoding prediction residuals. Simulation results demonstrate that the proposed residual dictionary yields superior performance as compared to other standard methods.

An image is called visually rich when its brightness and contrast are properly adjusted. But it was reported in different applications that the contrast of an image was affected by the external interferences. Due to the above phenomena, the image quality degrades. To improve the quality of the image, contrast enhancement method has been used. This technique adjusts the intensity distribution of the low-quality image to solve the problem. But the old techniques were not suitable for all kinds of images. To overcome the limitations, this paper presents a novel variational mode decomposition (VMD)-based enhancement technique associated with singular value decomposition (SVD). Initially, the reference images and the processed image were decomposed into various modes using variational mode decomposition (VMD). Then in the second step, the maximum value of the singular matrix was calculated for the selected mode of each image. An image-dependent correction factor was calculated using the singular value matrix (SVM). Finally, the image is reconstructed by simply adding the β-corrected mode image with the unprocessed modes of the reference image. To avoid the over-enhancement, a new weighted factor was applied to the original as well as to the enhanced image. To validate the algorithm, the proposed method was tested on different types of publicly available low contrast images. The experimental result shows that the proposed algorithm gives significant enhancement in terms of contrast over other state-of-the-art methods.

The enhancement, resolution, and accuracy are the basic requirements of digital image processing. But in the field of medical, the local details of the images are necessary. In this contest, the Contrast Limited Adaptive Histogram Equalization (CLAHE) is an effective approach, which is used for enhancing the local feature. The downside of CLAHE is the contrast overstretching and noise enhancement. To overcome this problem the low frequency and high-frequency details of an image were considered separately. This paper proposes a new biomedical image enhancement technique based on Bi-dimensional Empirical Mode Decomposition (BEMD) with CLAHE and Sobel Gradient. Where the image is decomposed using BEMD to separate the edge and detail information. The edge information is enhanced using CLAHE and the rest coefficients remain unchanged. Experiments are conducted on numerous brain, retina and tissue images to compare the performance of the proposed algorithm with the state of art approaches. The comparison is made quantitatively in terms of entropy ratio (ER), absolute mean brightness error (AMBE), the peak of signal to noise ratio (PSNR), structural similarity index (SSIM), and image quality index (IQI); qualitatively through visual comparisons. The results indicate a significant improvement especially in terms of structural and edge preservation.

Phytochemical content, antioxidant activity and reducing power of five ethnic medicinal plants of Manipur was analysed to study the antioxidant content commonly used by the traditional healers for the treatment of different inflammatory diseases and ailments. Antioxidant activity of methanolic extracts of five medicinal plants was investigated by using DPPH method which ranged from 47.82±0.041 per cent to 72.62±0.08 per cent inhibition. The phytochemical contents like total alkaloids, total flavonoids, total phenol, total carotenoids content ranged from 5.95±0.01 to 16.11±0.01 mg caffeine/100g on dry weight, 34.95±0.02 to 228.15±0.02 mg quercetin (QE)/100g on dry weight, 88.46±0.01 to 225.50±0.01 mg catechol equivalents (CE)/100g on dry weight, 0.81±0.005 to 3.80±0.005 mg/100g, respectively. Pearson correlation revealed a positive correlation between total phenol content, total flavonoids content, total carotenoids content and free radical scavenging activity (DPPH) of five medicinal plants extracts. However a negative correlation was found between total alkaloids content and free radical scavenging activity of medicinal plants extracts. The reducing power five medicinal plants extracts was statistically significant and positively correlated with DPPH free radical scavenging activity (r = 0.651; p

This paper describes about the Load Frequency Control (LFC) of an interconnected linear/nonlinear power system having two degree freedom of PID controller (2DOF-PID). The reheat thermal applied on a two-area system is considered for frequency control analysis by applying an abrupt load perturbation of 0.1 pu in area 1. Two systems are scrutinized for studying the load frequency control namely a linear system and a nonlinear system. The nonlinearities of the system are included by implementing governor with dead band (GDB) in each of the areas. The parameters of 2DOF-PID controllers are tuned on basis of Cuckoo Search Algorithm (CSA) considering time domain based fitness function, i.e., ITAE (Integral Time Absolute Error). For both types of system the dominance of 2DOF-PID controller is proved over conventional PID controller in terms of responses like minimum undershoot, settling time and peak overshoot. The supremacy of the recommended methodology is also established over some pre-published results.

Here a double loop PD+PI controller is projected to resolve the load frequency control issue in a dual area conventional hybrid source system. Basing up on a time variant fitness function Sine-cosine algorithm is employed to tune the PD+PI double loop controller's gains. The dual area unified system comprises three types of generating sources in all the areas named as gas, hydro and thermal unit. The system behavior is examined under two dissimilar conditions i.e. in presence of HVDC link and in absence of HVDC link. For both type of investigations an abrupt load perturbation of 1% is considered in first control area. The dominance of projected PD+PI double controller is verified over existing results of PID type conventional controller throughout the examination.

Proximate and elemental compositions of five soil-dwelling scarabs, Lepidiota mansueta Burmeister, Lepidiota albistigma Burmeister, Xylotrupes gideon (Linnaeus), Catharsius molossus (Linnaeus), and Sophrops iridipennis (Brenske), were assessed. Nutrient content varied widely, and the ranges of proximate contents were as follows: moisture (2.04–2.55%), crude protein (68.54–79.33%), crude fat (4.00–5.50%), crude fibre (5.16–8.28%), total mineral (0.80–4.98%), and carbohydrate (5.28–11.84%). Caloric content was greater in L. mansueta (379.29 kcal) compared to the other four species. The caloric contents of X. gideon (375.54 kcal) and C. molossus (375.19 kcal) were at par but significantly higher than those of L. albistigma (371.04 kcal) and S. iridipennis (361.55 kcal). Sodium content ranged 23.16–35.91 mg/100 g; potassium 14.20–44.33 mg/100 g; calcium 23.33–33.37 mg/100 g; iron 1.41–37.05 mg/100 g; copper 2.01–16.13 mg/100 g; zinc 2.38–15.86 mg/100 g; and manganese 1.09–19.66 mg/100 g. The phenol, flavonoid, and antioxidant activities of L. mansueta and L. albistigma were 4.00 and 6.42 mg catechol equivalent/g, 1.59 and 3.71 mg quercetin equivalent/g, 22.60, and 28.20%(DPPH activity), respectively. Tannin content was higher in L. albistigma (13.30 mg/g) than in L. mansueta (3.24 mg/g). Based on our study, these scarab species can be explored as food supplements and nutraceutical resources in ensuring food security.

As phospho proteins are reported to be involved in virulence and survival, the ability of Leishmani a to inhibit macrophage effector functions may result from a direct interference of leishmanial molecules with macrophage signal transduction pathways. Several such proteins such as pp63, pp41 and pp29 have also been identified as a Th1 stimulatory protein in the Leishmania donovani . In the present study, the immunogenicity of a cocktail of pp63 + pp41 + pp29 was assessed by estimation of serum antibody titre, nitric oxide(NO) production, estimation of Th1 cytokine(IFN-γ) as well as Th2 cytokines(IL-4), and determination of parasite load in L . donovani infected mice. In the group immunized with antigenic cocktail there was a sharp rise in antibody titer up to Day 20 which reduced considerably by Day 50. Groups of mice vaccinated with pp63, pp41, pp29 and the antigenic cocktail expressed 10-fold, 16-fold, 22-fold and 25-fold increase respectively in NO production by splenocytes. The animal groups immunized with pp63, pp41, pp29 and the antigenic cocktail showed reduced parasite load in the liver and spleen, as well as increased IFN-gamma production in the spleen. Furthermore immunized animals remained with a normal hematological profile, whereas L . donovani in unimmunized mice lead to significant anemia.

This research paper paid a strong attention towards the development of an optimized controller called the Proportional integral derivative controller with derivative filter (PIDF), which has been used in the automatic generation control for three unequal systems. This paper has utilized a hybrid control scheme by hybridizing differential evolution technique along with particle swarm optimization algorithm so as to optimize the values of the controller gains. Inclusion of Generation Rate Constraints (GRC) has been done here to account for system nonlinearities. An error function known as integral time absolute error (ITAE) has been considered here as the objective function in order to tune the values of the controller gains which will increase the efficiency of the controllers. The dynamic performance of the system is put to comparison with pre-published method and the efficiency is established strongly. Further analysis has been conducted to establish the stoutness of this system when put to different loading conditions.

Nowadays image compression has become a necessity due to a large volume of images. For efficient use of storage space and data transmission, it becomes essential to compress the image. In this paper, we propose a dictionary based image compression framework via sparse representation, with the construction of a trained over-complete dictionary. The over-complete dictionary is trained using the intra-prediction residuals obtained from different images and is applied for sparse representation. In this method, the current image block is first predicted from its spatially neighboring blocks, and then the prediction residuals are encoded via sparse representation. Sparse approximation algorithm and the trained over-complete dictionary are applied for sparse representation of prediction residuals. The detail coefficients obtained from sparse representation are used for encoding. Experimental result shows that the proposed method yields both improved coding efficiency and image quality as compared to some state-of-the-art image compression methods.

This paper presents a single-phase grid-connected photovoltaic power system with the capability of maximum power point tracking (MPPT) of photovoltaic (PV) array and reactive power compensation. The non linear characteristics of the proposed modified p-q theory have been improved with the help of maximum power point tracking (MPPT) controller. MPPT controller helps to feed the inverter with maximum power from the solar grid, for switching pattern generation hysteresis controller is used. The simulation results developed in MATLAB/Simulink software, verify the performance and advantages of the proposed system used to integrate the single phase grid to photovoltaic for enhancing the power quality. Also the proposed scheme has been verified in laboratory setup for its real time implementation.

For better utilization of millets, two processing techniques, viz., popping and malting were standardized using two local varieties of foxtail millet (Setaria italica). In popped samples, crude fat and crude fibre contents were significantly lower than raw millet in both the yellow and purple varieties, while the carbohydrate and energy values were significantly higher. In malted samples, crude protein and fat contents were significantly lower than in raw millet in both the varieties, whereas the carbohydrate contents were higher. Starch digestibility was highest (42.4%) in yellow popped samples and lowest in yellow malted samples (21.8%). Protein digestibility was highest (13.2%) in purple popped and lowest (2.4%) in yellow malted samples.

In order to enhance the control action, in this article multi degree of freedom PID controllers (MDFPID) like 2DOF-PID and 3DOF-PID controllers are suggested for frequency control in a multi-unit hydro-thermal interconnected system. The finest gains of the recommended MDFPID controllers are achieved with Grey Wolf Optimization (GWO) Technique considering a time based evaluative function. The dom-inating performance of the suggested control technique is validated by relating the outcomes with a pre-published journal results. The robust behavior of the MDFPID controller is also validated by abruptly amplifying the loading of the system. The system dynamic responses are analyzed in consideration with time response parameters like minimum undershoots, settling time and peak overshoots.

This paper deals with active and reactive power control of a three phase grid connected photovoltaic system. Maximum power point tracking (MPPT) algorithm is used to track the MPP. The MPPT algorithm uses the IPV and VPV of the PV array and gives the MPP and a Vdc,ref. This voltage is then passed on to the inverter and then further to the three-phase grid. The behaviour of the active and reactive power of the grid which is supplied by the PV array is investigated. The various currents such as inverter current, grid current and load currents are also investigated. MATLAB/simulink has been used to carry out the simulations. The proposed work has also been experimentally verified.

Nowadays, image compression is very important for efficient data storage and transmission. This paper presents a dictionary-based intra-prediction framework for image compression using sparse representation, with the construction of trained over-complete dictionaries. The intra-prediction residuals selected from different images and K-SVD algorithm are used to train over-complete dictionaries. The trained dictionaries are integrated into the intra-prediction framework for efficient image compression. In this proposed method, first, intra-prediction is applied over an image and then prediction residuals of the image are encoded using sparse representation. Sparse approximation algorithm and trained dictionaries are employed for encoding of prediction residuals of the image. The coefficients obtained from sparse representation are used for encoding. For efficient sparse representation with fewer dictionary coefficients, an adaptive sparse image partitioning method is introduced. Simulation result demonstrates that the proposed image compression method yields improved encoding efficiency as compared to existing schemes.

In this paper, solar array current is estimated and observed with a sliding mode observer instead of having a sensor, the observer is based on sliding-mode control and is constructed from the dynamic equations of the considered system vis. a single phase grid connected photovoltaic system that has a photovoltaic module and a single-phase H-bridge inverter. The solar array current is observed by the known values or measured values of the array voltage and inductor current. The current estimation is governed by the sliding mode observer gain, with decrease in the value of the gain, chattering problems become reduce. Observer gain has been varied from 100% of designed value to 6.25% of its value. A compromise has been made between estimation accuracy and chattering, to get an effective result at 12.5% of the designed value of observer gain. The estimated value almost follows the original current and hence, is used to track the MPP rapidly. Methodology of grid integration of distributed photovoltaic systems is explored and simulated using MATLAB/Simulink. The simulation results prove the effectiveness of the proposed method for efficient grid integration.

Assam is a north eastern state of India with a typical food habit distinct from the rest of the country. In order to document the nutrient composition of the regional recipes of Assam, some of the ...

A method for calculating the photoemission matrix element with the inclusion of spatial variation of the photon field is presented. The initial and final states are taken to be the same as in the time-reversed LEED formalism, and the vector potential of the photon field is assumed to be local and to vary only along the direction normal to the surface.

The colours extracted from neem bark with different concentrations of mordants were tested on silk for the shades and colour fastness properties. The mordants tested were CuSO4, Al2(SO4)3, alum and citric acid. The colours of the fabrics were studied with a Hunterlab colour scale and the maximum AE* value (51.48±0.60) was observed for 1% CuSO4 mordant treated samples. However, the values were not significantly different from 2% and 3% CuSO4 treated samples. The unmordanted samples were also statistically acceptable in terms of AE* values. The change in chroma values were maximum for the 2% citric acid mordant (37.22±0.69), though the change in chroma offered by 2% and 3% alum, 3% citric acid and unmordanted samples were not significantly different. All the mordanted samples had fair to good (3–4) fastness to washing. The staining on undyed silk fabric with citric acid mordant showed excellent (5) fastness followed by alum and CuSO4 mordanted samples, which had good to excellent fastness. CuSO4 mordant offered good fastness to washing. The alum, Al2(SO4)3 and citric acid mordants exhibited excellent dry rubbing fastness whereas the CuSO4 mordant showed good to excellent (4–5) fastness. In case of wet rubbing, alum, citric acid and Al2(SO4)3 mordanted samples showed good to excellent (4–5) colour fastness. Colour fastness in case of CuSO4 mordant was good (4). The CuSO4 mordant offered fairly good (4) colour fastness to sunlight and all other mordants showed moderate (3) colour fastness. The samples without mordants exhibited poor fastness (2). In view of the colour fastness, viz. fastness for washing, rubbing and exposure to light, the neem bark dye should be applied with any of the mordants used for the study at 3% level.