Search

In this work, the industrial case study of effluent drying with a direct and hybrid heat recovery configuration is investigated for the purpose of improving heat recovery potential and understandin...

Superheated steam is a vital drying media due to inherently passive, nonpoisonous, no fire risk, antioxidant, and compatible with food products with superb thermophysical properties than hot air. M...

Objectives To determine the prevalence of critical illness polyneuropathy and its risk factors in critically ill children mechanically ventilated for 7 days or more. Design Observational cohort study. Setting PICU of a tertiary care hospital from North India. Patients Children 1-15 years old admitted in PICU from June 2016 to September 2017, mechanically ventilated for 7 days or more, excluding those with diagnosed neuromuscular disease, stroke, or spinal pathology. Intervention Demographic details, diagnosis, treatment details, and anthropometry at admission and enrolment were recorded. Nerve conduction studies were performed after enrolment and repeated a week later, if the child was still in PICU. Medical Research Council scoring for muscle strength was performed in survivors. Risk factors including Pediatric Index of Mortality-2 score, sepsis, multiple organ dysfunction, hypoalbuminemia, use of steroids, neuromuscular-blocking agents, and vasopressors were recorded. Samples for the level of micronutrients (copper, zinc, folate, and vitamin B12) were collected at the time of enrolling the child and at the time of discharge. Measurements and main results Thirty-two children were enrolled, of whom 29 had features of critical illness polyneuropathy on evaluation at day 8 of mechanical ventilation (prevalence, 90.6% [95% CI, 80.5-100%]). The polyneuropathy was axonal in 26 (81.2%), mixed in one patient (3.1%), and uncharacterized in two (6.2%). Sepsis and multiple organ dysfunction were present in 31 subjects (96.9%). No risk factors for critical illness polyneuropathy could be identified although the study was not sufficiently powered to do so. The difference between serum micronutrient levels (copper, zinc, folate, and vitamin B12) between patients who developed polyneuropathy, and those who did not, was statistically insignificant. Conclusions We observed a high prevalence of critical illness polyneuropathy in children in PICU, mechanically ventilated for 7 days or more; almost all of whom had underlying sepsis.

This paper presents the optimal step least mean square algorithm for controlling three-phase distributed static compensator (DSTATCOM). The presented algorithm provides harmonic compensatio...

Thermal dewatering using spray dryers is an energy-intensive process, which recently, applied for removal of water from industrial effluents by evaporation. Reduction of energy consumption is vital to reduce operating cost in addition to sustainable development. In this paper, the modern integrated energy savings scheme is proposed in four parts. (i) An advanced energy saving configuration named as a hybrid heat recovery system for a spray dryer, (ii) Developed rigorous but simple mathematical model for direct and hybrid heat recovery system, (iii) A generalized performance indicator for investigation of environmental impact on energy recovery called as ‘Sustainability Index’ is proposed for thermal systems and demonstrated for spray dryer, and finally (iv) The proposed methods are explained with the help of an illustrative example taken from the literature. Up to 80% recirculation ratio, performance enhancement, and Sustainability Index are significantly higher for the hybrid heat recovery system than the direct heat recovery system, while for higher than 80% recirculation ratio, both are approaching towards nearly same value. Furthermore, with increasing recirculation ratio, moisture recirculation into the drying chamber also increases, which reduces the requirement of the mass flow rate of dry hot air due to the higher heat capacity of recirculated moisture. A reduction in hot air requirement reduces the high-grade blower power in addition to net heat supplied. Dryer efficiency and sustainability index, both show a strong dependency on the amount of heat recovery for spray dryer.

The production levels of agriculture have remained low in eastern region of India mainly due to lack of location-specific production technologies, natural calamities like floods, water logging, drought, inadequate timely supply of critical inputs and social constraints. Bihar is one of the important agrarian states of Eastern India. The crop yields are low and almost stagnating in Bihar compared to the north-western and other parts of the country. To improve the productivity in this region mechanization of farms is of critical importance. The farm power availability in Bihar in 2017 is 2.80 kW/ha and is more than the national average of 2.03 kW/ha. Still there are 14 districts in Bihar which is below national average. The number of marginal farmers has increased from 84.18 to 91.21 during 2014-17, an increase of 7.03 percent. Increase in Small and fragmented land will further hindrance the farm mechanization process. The present study was conducted to understand dynamics of farm power availability in Bihar, so as to take substantial measures for improved mechanization and in turn crop productivity in the region.

Harmonic-related power quality problems can be solved using a distribution static compensator (DSTATCOM) system, but its performance is very prone to frequency nonadaptiveness and harmonic disturbance presence in the control scheme. In this paper, a new control scheme based on frequency-adaptive disturbance observer is presented to improve power quality at the distribution supply. The proposed disturbance observer is utilized to remove the harmonics from the nonlinear load, thereby enhancing the magnitude estimation accuracy of the fundamental load current. The performance of the proposed control scheme has been assessed with a prototype model. The simulation as well as experimental results shows that the operation of DSTATCOM system is satisfactory for power quality improvement.

The design of thin-film multilayered anti-reflection (AR) coating is quite an intricate task due to highly nonlinear and complex dimensional search space, which includes many local minima. In this paper, a novel teaching-learning based optimization (TLBO) approach is employed to design ultra-low reflective coating over a broad wavelength-band using multilayer thin-film structures for optoelectronic devices. The algorithm is implemented using LabVIEW as a programming tool. Various design specific input parameters such as scanning range of wavelengths, step-size, angle of incidence, number of layers, the name and sequence of coating materials etc. are required to be fed by the user on the graphical user interface. The algorithm minimizes the average reflectivity computed over given wavelength range by tuning the thickness of layers in the multilayer stack. The reliability and evolution of design solution with iterations have been systematically investigated for different learner-sizes. Finally, using the optimized learner size and desired number of iterations, the optimum AR design is obtained in terms of the thickness of each layer for the multilayer AR coating. The effectiveness of the TLBO approach has been compared with that of an established algorithm, i.e. genetic algorithm (GA), by means of Wilcoxon singed ranked test. It is concluded that the TLBO can be a very efficient, simpler and relatively faster approach to address complex optimization problems such as broad-band AR coating designs.

This paper presents nonlinear adaptive Volterra filter for control of three-phase four wires Distribution Static Compensator under mixed type linear and nonlinear load. The proposed adaptive filter identifies and measures active and reactive weights of the fundamental components of load currents. These weights are used to generate the reference signals such that the currents drawn from a supply are close to balanced and sinusoidal. The performance of the proposed control algorithm is observed under nonlinear load in the laboratory environment. The test results are found satisfactory as total harmonic distortion in supply currents are within the 5% levels specified by the IEEE Standard 519-1992.

The ultrasonic metal welding is an industrial technique whereby high-frequency ultrasonic acoustic vibrations are locally applied to the workpiece being held together under pressure to create a solid-state weld. In the present study, ultrasonic metal welding was successfully carried out on the material 0.3-mm molybdenum TZM alloy with pure aluminium interlayer. Al interlayer of 0.2, 0.25 and 0.3 mm thickness is inserted in between the faying surface. Experiments of ultrasonic metal welding were performed using Taguchi’s L27 orthogonal array. The weld strength of the welded joints is measured using tensometer. Results show that weld strength is increasing with an increase in pressure and weld time. Further, ANOVA result indicates that pressure and weld time have a maximum contribution on weld strength.

In this investigation, the emphasis is given to the partial replacement of carbon black by an optimized level of Cloisite 15A, an organoclay in a typical styrene-butadiene rubber (SBR) based passenger car tire tread compound. The effect of epoxidized natural rubber with 50 % epoxidation (ENR 50) on the properties of organoclay-SBR composite was also studied. Curing studies shows that both ENR 50 and nanoclay decreases the scorch time and cure time due to the activation of an adjacent double bond by the presence of epoxide group in the ENR and the amine groups present in the organic modifier in the nanoclay structure. The incorporation of ENR showed better dispersion and exfoliation of nanoclay in the rubber matrix. Synergistic reinforcement effect of high abrasion furnace carbon black (HAF/N330) on the mechanical properties, dynamic mechanical properties, heat build up and abrasion resistance in the SBR–ENR–clay nanocomposites having the optimized clay level was investigated. SBR–ENR–carbon black hybrids with 25 phr N330 and 6 phr nanoclay have shown better reinforcement, significantly lower heat generation, comparable/similar rolling resistance (indicated by tan δ at 60 °C) and wet skid resistance with that of conventional SBR–carbon black (40 phr N330) loaded composites.

This article presents the three-phase enhanced phase-locked loop control of a three-phase distribution static compensator under linear and non-linear loads for improving power quality. The proposed control algorithm adaptively estimates the active and reactive fundamental components of load currents for estimation of reference supply currents, which minimizes the supply current total harmonic distortion within the limits of IEEE Standard 519. The simulation model of the proposed system is developed by using the MATLAB/Sim Power Systems toolbox (The MathWorks, Natick, Massachusetts, USA), and its results are found acceptable to diminish harmonics distortions, reactive power compensation, and load balancing in both power factor correction and zero voltage regulation modes.

In this study, an interior point optimisation-based control algorithm is proposed for three-phase distribution static compensator under distorted AC mains. The proposed algorithm is used to determine the optimal value of load fundamental conductance and susceptance, which minimises the supply apparent power, subjected to predefined total harmonic distortion (THD) and individual harmonic distortion limit of supply current as per international guidelines. Unlike the other optimisation techniques, this technique is based on matrices calculations, which makes it effective during load dynamics. The proposed control scheme is implemented for mitigating multiple power quality issues such as load balancing, reactive power compensation and harmonics suppression in power factor correction and zero-voltage regulation modes under linear and non-linear loads.

Industrialisation seemed to be the key to a better wealthy life, although it contributes to climate change. Resulting in the stakeholders' behaviour drastically tends towards the reduction of carbo...

Energy recovery is essential as it reduces fuel cost and pollution due to emission of flue gases. The energy recovery potential can be easily determined by pinch analysis, where individual fluid streams obey mass balance. However, in this paper, pinch analysis based methodology is proposed for energy targeting of evaporative systems such as dryers where the mass balance of individual streams is not possible due to loss of identity of one of the streams (feed) because of evaporation of water content and separation of the solid part. Initially, a spray dryer with a counterflow arrangement is selected to demonstrate the applicability of pinch analysis for targeting of energy requirement considered as the base case. Additionally, three different heat recovery configurations integrated with spray dryers are explored by pinch analysis for energy targeting as: (i) direct heat recovery, (ii) indirect heat recovery, and (iii) hybrid heat recovery systems. Further heat recovery potentials and their effect on the performance of the drying process are evaluated appropriately for different cases based on exhaust gas temperatures. The pinch analysis shows that with decreasing a mass flow rate of supply gases/air, the exhaust losses are also reducing for spray dryer integrated with all configuration of the heat recovery system. For spray dryer with indirect heat recovery configuration, energy-saving potential with and without exhaust gas/air temperature constraint is achieved as 57 and 68%, respectively, for a given illustrative example. Among all configurations, a hybrid heat recovery system with 80% recirculation is having the highest thermal energy saving potential (74%) compared to the base case. Moreover, the reduction in the driving potential of spray dryers for direct and hybrid heat recovery configurations is appropriately analyzed for new as well as retrofitted drying systems. It is observed that the effect of driving potential is insignificant for a lower recirculation ratio. Further, techno-economic analysis reveals that there are substantial energy savings even after considering the driving potential suitably in new and retrofitted spray dryers with heat recovery systems.

Dryers are used for removal of moisture from an raw materials (such as effluent) to form a dried solids as per the requirements. For removal of the moisture, energy requirement is huge. Therefore, in this paper, methodology for heat recovery in one of the type of dryers as spray dryers is developed, which is simple and easy to apply. The proposed methodology is illustrated with the help of an example taken from literature. It is observed that the indirect heat recovery method could save energy maximum up to 82 % as compared to literature and 41 % higher than without heat recovery. Keywords: Spray dryer, pinch analysis, heat recovery, effluent drying, energy saving

This paper describes a systematic investigation on the use of the genetic algorithm (GA) to accomplish ultra-low reflective multilayer coating designs for optoelectronic device applications. The algorithm is implemented using LabVIEW as a programming tool. The effects of the genetic operators, such as the type of crossover and mutation, as well as algorithm parameters, such as population size and range of search space, on the convergence of design-solution were studied. Finally, the optimal design is obtained in terms of the thickness of each layer for the multilayer AR coating using optimized genetic operators and algorithm parameters. The program is successfully tested to design AR coating in NIR wavelength range to achieve average reflectivity (R) below 10 −3 over the spectral bandwidth of 200 nm with different combinations of coating materials in the stack. The random-point crossover operator is found to exhibit a better convergence rate of the solution than single-point and double-point crossover. Periodically re-initializing the thickness value of a randomly selected layer from the stack effectively prevents the solution from becoming trapped in local minima and improves the convergence probability.

The determination of values of solar cell parameters is of great interest for the evaluation of solar cell performance. This paper proposes a simple, efficient and reliable method to extract all five parameters of a solar cell from a single illuminated current–voltage (I–V) characteristic using teaching learning based optimization (TLBO) algorithm. The TLBO is implemented by developing an interactive numerical simulation using LabVIEW as a programming tool. The effectiveness of the algorithm has been validated by applying it to the reported I–V characteristics of different types of solar cells such as silicon, plastic and dye-sensitized solar cells as well as silicon solar module. The obtained values of parameters by the TLBO algorithm are found to be in very good agreement with reported values of parameters. The algorithm is also applied to the experimentally measured I–V characteristics of a silicon solar cell and a silicon solar module for the extraction of parameters. It is observed that the TLBO algorithm repeatedly converges to give consistent values of solar cell parameters. It is demonstrated that our program based on TLBO algorithm can be successfully applied to a wide variety of solar cells and modules for the extraction of parameters from a single illuminated I–V curve with minimal control variables of the algorithm.

Background: Iron requirements are increased in adolescent girls with growth and the onset of menarche and remain high in women until menopause. Methods: We conducted a study on first year medical college female students (age group 18-25 years) belonging to socioeconomic classes 1 and 2 as per the Modified Kuppuswamy’s Scale to study the effect of the phases of menstrual cycle on the iron status indicators (ISI) (Hb, Serum Iron, TIBC, MCV and TS%). Menstrual phases were defined and blood samples were drawn from all the girls in all the 3 phases (menstrual, follicular and luteal) and Hb, Serum iron and Total iron binding capacity were assessed on a semi-auto-analyzer and MCV was estimated using a fully automated CBC machine. Transferrin Saturation was derived as Serum Iron / TIBC × 100. Results: We found significant (p

This paper discusses an Amplitude Adaptive Filter (AAF) based control algorithm for distribution static compensator (DSTATCOM) in three-wire supply system. The DSTATCOM is used in the power factor correction mode for removal of current-based power quality issues such as source-side current harmonics, poor power factor along with load balancing. An AAF not only computes the amplitude and frequency of the signal but it is also adapting the amplitude of the signal under variations. The estimated amplitude is employed to create the reference source currents to generate gating pulses. Tests were carried out using real time digital simulators (RT-LAB) to validate the function of DSATCOM in distribution system.

Styrene butadiene rubber-organoclay nanocomposites were prepared with Cloisite 15A via melt intercalation. X-ray diffraction and transmission electron microscopy indicated that the nanostructures are partially exfoliated and intercalated. The nanocomposites exhibited great improvements in tensile strength and tensile modulus. The incorporation of organoclay gave rise to considerable reduction of tan delta and increase in storage modulus in the rubbery region. It is shown that after 6 phr (parts per hundred rubber) clay loading there is not much increase in the properties. The effect of carbon black (N330) on mechanical properties, dynamic mechanical properties, heat build up, abrasion resistance in the nanocomposites having the optimized clay level (6 phr) was investigated. Optimum results were obtained with the addition of 25 phr carbon black. For comparison with the 6phr nanoclay and 25phr N330 (high abrasion furnace carbon black) filled SBR composites, 40 phr N330 filled SBR composites was used. The 6phr organoclay and 25phr N330 filled SBR nanocomposite showed better properties than 40phr carbon filled SBR compound. These results indicate that 6phr organoclay can be replaced by 15 phr carbon black from the conventional SBR-carbon black based tire tread compounds. The Dynamic mechanical analyzer (DMA) results revealed that the new tire tread compound gives better rolling resistance and comparable wet grip resistance and lower heat build up than that of conventional tread compound.

This paper propose an adaptive filter based on continuous time LMS for the distribution static compensator. The Simulink model is constructed in MATLAB software of the complete system along with adaptive control algorithm and rectifier type nonlinear load. It is seen from the test results that the presented LMS adaptive filters accurately estimate the active component weight of the currents from the given nonlinear currents. These weight components are utilized to produce reference currents and subsequently switching pulses for the voltage source converter of the compensator are generated. This three-phase with four-wire DSTATCOM system provides necessary compensation in terms of harmonic current, reactive power and neutral current as well.

Summary In this paper, a 3-phase extended structure-enhanced phase-locked loop (ESEPLL)–based control algorithm is proposed for a 3-phase 4-wire DSTATCOM (distributed static compensator) at linear and/or nonlinear consumer loads. A major feature of this control algorithm includes accurate and adaptive estimation of instantaneous fundamental positive sequence components of load currents at nonideal AC mains. In a highly distorted and highly unbalanced grid supply voltages, conventional phase-locked loop technique fails to extract the required signals. In such situation, the ESEPLL technique is used for estimating the reference supply currents. The proposed scheme not only enhances the performance of DSTATCOM system but it also provides the instantaneous compensation of harmonics currents, reactive power, unbalancing, and neutral currents due to load behavior. A single unit of ESEPLL technique is used in a 3-phase system for desired performance with necessary mathematical analysis. The control algorithm is tested on DSTATCOM using DSP-d-SPACE1103 interface with MATLAB. The obtained test results on a developed prototype show that the proposed control technique succeeds to enhance the power quality at point of common interface under various loading conditions in full-scale voltage at distribution level.

The precise determination of refractive index (n) of material and thickness (t) of thin-films are desirable for many applications in the field of optics and optoelectronics. In the proposed work, we have utilized a computational genetic algorithm (GA) to find the refractive index and the thickness from the experimentally measured reflectivity spectra of thin-film. The algorithm was implemented using the Lab VIEW as a programming tool. The obtained results show that the prepared algorithm successfully calculates the spectral dependence of refractive index and thickness of thin-films by fitting an experimentally measured reflectivity spectra with the calculated ones.

This paper deals with the springback analysis in sheet metal forming using modified Ludwik stress-strain relation. Using the deformation theory of plasticity, formulation of the problem and spring back ratio is derived using modified Ludwik stress strain relationship with Tresca and von Mises yielding criteraia. The results have been representing the effect of different value of or ratio, different values of Strain hardening index (), Poisson’s ratio (), and thickness on spring back ratio (). The main aim of this paper is to study the effects of the thickness, ratio, and Poisson’s ratio in spring back ratio.

Macrophage responses to infection with Mycobacterium tuberculosis (MTB) and treatment with soluble isoniazid (INH) plus rifabutin (RFB) versus microparticles containing equivalent amounts of drugs were compared. It was investigated whether macrophages driven to alternative activation upon infection with MTB could be rescued to display the classical activation phenotype. It was established that microparticles sustain high levels of drugs in cytosol of macrophages for longer period as compared to soluble drugs. Microparticles co-localized with intracellular bacteria, and induced a variety of innate bactericidal responses, including induction of free radicals, alteration of mitochondrial membrane potential and apoptosis. The data strongly suggest that additional benefit may be derived from the nature of the drug delivery system, which fulfils Koch's dictum 'stimulate the phagocyte' for curing tuberculosis.

Solar photovoltaic module operating with constant solar irradiance needs entire power (P)-voltage (V) curve tracing to find the maximum power point (MPP), if perturb and observe or incremental conductance algorithms are used. Therefore, there is a need of an algorithm which tracks the MPP without tracing entire P-V curve. This paper focuses on an MPP prediction method which is only based on a few data collected in the open-circuit and short-circuit regions of current (I)–voltage (V) curves of a cell or a module. The work presented here assumes I-V curve of a module to follow I-V power relation, I = aVb + c. The power model coefficients a, b, and c are determined by teaching-learning based optimization. The voltage at the MPP (Vmp) is computed by correlating the incremental conductance algorithm with the I-V power model and thereafter power at the MPP (Pmax) is obtained. The effectiveness of the algorithm is confirmed by applying it to the reported I-V curve of different types of solar cells. The obtained ...