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In this study, the thermal and drying characteristics of a thin layer food sample were investigated. An indirect type, simple, efficient, and economically feasible solar dryer was fabricated and used for food preservation. However, a dynamic model of a fabricated solar dryer was also presented to gain a better insight into the drying and thermal actions. This model consists of thermal modeling of the drying chamber, solar collector, and solar-dried food sample. The law of conservation of energy was applied to evaluate the temperature at different sections of the solar dryer with respect to drying time. All listed model equations were solved in the MATLAB environment. This study helps to examine the influence of solar radiation on the collector plate temperature, drying chamber temperature, food sample temperature, and performance parameters such as thermal efficiency with respect to drying time. Model data was found in good agreement with experimental data within a 4% error. It is concluded that the drying of food material is affected by air temperature, the collector temperature, mode of heat transfer, and material characteristics such as dimension and mass of the food sample. [ABSTRACT FROM AUTHOR]

Purpose: This study provides a comprehensive examination of the free vibration responses exhibited by adhesive-bonded double lap joints. The outcomes derived from this approach provide invaluable insights for optimizing the performance and stability of adhesive-bonded double lap joints in engineering applications. Methods: To assess the natural frequencies of these joint structures, a finite element analysis is employed. The natural frequency parameters obtained are then compared with existing literature, revealing a strong concurrence that substantiates the precision and consistency of the study. The investigation delves into the influence of various design parameters, including material properties, stacking patterns, and aspect ratios, on the modal analysis of these joint structures. Results: This research conducts a significance and sensitivity analysis to assess the impact of diverse factors on the natural frequencies of adhesive joints. Utilizing an analysis of variance (ANOVA) method, modal frequencies can be predicted. Outcomes revealed that one-sided fixed support results in a 79% lower natural frequency, and modal frequencies increase with changing elasticity-to-adhesive ratios. Plate length has the most significant influence on modal frequencies, and the ANOVA analysis yielded an average error of 2.871%. Conclusions: This study found that the combination of Poisson's ratio and shear modulus significantly impacts the vibration of glass/epoxy double lap joints. [ABSTRACT FROM AUTHOR]

Wire electro-discharge machining (Wire-EDM) is one of the most versatile and efficient manufacturing process to machine difficult-to-cut materials. In this experiment, wire-EDM of Inconel 625 work piece material is performed by using zinc coated brass wire as wire electrode and distilled water as dielectric fluid. Input parameters taken during experimentation are pulse-on-time (Ton), pulse-off-time (Toff), and servo voltage (Sv). Here, experiments are conducted as per Taguchi's experimental design i.e. L9 orthogonal array to study the effect of machining parameters on the output responses. To access the machining performance of the wire-EDM process during machining of Inconel 625, the output responses considered are material removal rate (MRR), kerf width (Kw), and average surface roughness (Ra) of the machined surface. For multi-objective optimization of these output responses during the wire-EDM process, desirability function approach is used to achieve better machining performance i.e. higher MRR, lower Kw and lower Ra. The optimum parametric setting for better machining performance is obtained to be Ton = 18 µm, Toff = 53 µm, Sv = 23 V. Also, analysis of variance (ANOVA) is performed to study the influence of machining parameters on the overall output performance (composite desirability). Here, pulse-on-time is found to be the highest significant factor with percentage contribution of 64.14% for composite desirability. [ABSTRACT FROM AUTHOR]

Thermochemical parameters of A4-sized printing paper (AP), filter paper (FP), newspaper (NP), writing paper (WP), and reed pith (RP) samples were estimated using standard protocol to identify its fuel characteristics, and thermal degradation of the same was studied using thermogravimetric analysis (TGA) and differential thermogravimetric (DTG) techniques in the temperature range of 30–800 °C at the heating rates of 10, 15, and 20 °C/min under nitrogen atmosphere. The curves of TGA and DTG exhibited four significant stages. Maximum weight loss was found to be in the second stage. Kinetic analysis was carried out in the conversion range of 0.1 to 0.7 using iso-conversational models of Flynn-Wall-Ozawa (FWO), Kissinger-Akahira-Sunose (KAS), Vyazovkin, and Vyazovkin AIC (V.AIC). The average activation energies were found to be 139.90, 115.93, 212.52, 257.41, and 241.63 kJ/mol using FWO; 129.73, 103.06, 202.46, 248.38, and 231.55 kJ/mol using KAS; 145.57, 134.00, 195.29, 256, and 241.63 kJ/mol using Vyazovkin; and 140.71, 133.86, 193.14, 247.57, and 190.14 kJ/mol using Vyazovkin AIC model. Thermodynamic parameters (enthalpy change (ΔH), Gibbs free energy change (ΔG), and entropy change (ΔS)) using these models have been evaluated. [ABSTRACT FROM AUTHOR]

Over the years, biodegradation has been an effective technique for waste water treatment; however, it has its own limitations. In order to achieve a higher degradation efficacy, integrated processes are being focus in this area. Therefore, the present study is targeted towards the coupling of biodegradation and photocatalytic degradation of p-cresol. The biodegradation of p-cresol was performed via lab isolate Serratia marcescens ABHI001. The obtained results confirmed that ~85% degradation of p-cresol was accomplished using Serratia marcescens ABHI001 strain in 18 h. Consequently, degradation of remaining residue (remaining p-cresol concentration initially used) was also examined in a batch reactor using activated carbon−TiO2 nanocomposite (AC/TiO2-NC) as a catalyst under the exposure of UV radiation. The AC/TiO2-NC was processed via sol-gel technique and characterized by various techniques, namely Brunauer-Emmett-Teller (BET), scanning electron microscope (SEM), X-ray diffraction (XRD), and Fourier transformed infrared spectroscopy (FT-IR). The investigation allowed p-cresol degradation further augment up to ~96% with the help of spectrophotometer trailed by high performance liquid chromatography (HPLC). This study demonstrates that integrated process (biodegradation-photodegradation) is the cost-effective bioremediation process to overcome such kinds of pollutant issues. [ABSTRACT FROM AUTHOR]

The damaged laminated composite structural strength and repair action due to functional material reinforcement is investigated mathematically in this research using a higher-order displacement field model. The effect of a crack on the frequency responses is predicted numerically using the finite element (FE) approach. The reduction in total structural strength due to the crack and elevated temperatures are computed using the proposed model. Further, the enhancement of parent structural strength/stiffness is achieved by reinforcing the shape memory alloy (SMA). Moreover, the damage repair and improved frequency are achieved through activated SMA under a temperature range. The numerical model efficacy is established by conducting the convergence and adequate comparison studies. The study of the cracked laminate is verified for different temperature ranges, with and without SMA fiber. Additionally, a few experimental frequencies of intact and damaged composite panels have been carried out for comparison to gain confidence in the proposed model. Finally, several numerical examples are solved by varying the important structural input parameters (material and geometry) and their influences discussed in detail. [ABSTRACT FROM AUTHOR]

Polyvinylidene fluoride (PVDF)/TiO2 composite ultrafiltration membranes were fabricated using different loadings of TiO2 NPs synthesized by the green route using an extract of Cajanus cajan. XRD analysis confirmed the synthesis of TiO2 nanoparticles of size 10 nm using Debye Scherrer's equation. High hydrophobicity of PVDF restricts its successful application due to fouling in the membrane. Therefore, composite membranes were prepared via the phase inversion route and characterized by contact angle and permeation tests. The BSA filtration experiments revealed that membrane with 0.5 wt% of TiO2 exhibits excellent hydrophilicity, permeation flux, high rejection ratio, and good antifouling performance. It was observed that the fouling characteristic of the membrane is governed by the surface roughness of the membrane, and with increasing loading of TiO2 the surface roughness decreases indirectly enhancing the antifouling property of membranes. The adsorption capacity of bovine serum albumin on the membrane surface decreased from 2.85 to 2.15 mg cm−2 as the TiO2 loading increased from 0 to 0.02 g TiO2/g PVDF. Fouling was found due to cake formation in ultrafiltration and can be explained by Hermia's fouling model suggesting that the solutes are not deposited into the pores, which indicates that the fouling process is physically reversible. [ABSTRACT FROM AUTHOR]

The purpose of the present study was to determine whether age would disrupt fear retention and extinction memory in rats pre-exposed to maternal separation and isolation stress; these rats are called MS rats. MS stress was induced by exposing rat pups into maternal separation followed by isolation stress from peer groups (MS) daily/6 h during stress hyporesponsive period, while controls rats that were undisturbed during this period are called NMS rats. 5, 8, 15 and 52 weeks later, these animals were exposed to classical fear conditioning test by pairing auditory stimulus (conditioned stimulus, CS+) with electric footshock. 24 h later, conditioned freezing response to CS+ was measured during fear retention, extinction and extinction recall trials. The normal ageing per se did not affect the formation of fear memory, retention and fear extinction memory. MS stress, on the other hand, disrupted fear memory at young adulthood age exhibiting increased freezing response to CS+ during retention test and reduced during fear extinction memory test when compared to NMS groups. On the other hand, rats at adolescence age exhibited reduced freezing during fear retention and enhanced freezing response to CS+ during extinction recall test. However, MS-induced changes in freezing response during fear retention and extinction tests were not seen in adulthood and 1-year-old age groups. These data demonstrate the young adulthood age is highly vulnerable to fear memory and extinction processes. The differences in freezing response to CS+ during fear conditioning from adolescence to old age, thus, appear to be related to the maturation of the limbic circuit. [ABSTRACT FROM AUTHOR]

Organic fertilization enhances the global warming potential of the soil, which is primarily attributed to higher CO2 emission from the soil. However, long-term studies under organic fertilization to observe its impact on soil’s warming potential with respect to CO2 efflux are limited in the dry tropical ecosystem. Therefore, we observed the changes in soil organic matter (C, N), soil CO2 efflux (SCE), soil moisture, microbial biomass C, and dehydrogenase activity in the plots under 1, 3, 5, and 10 years of organic fertilization, designated as OM1, OM3, OM5, and OM10, respectively. Also, a nearby native forest was taken as a standard reference system (NF) in the present study for comparative purpose. We observed that organic fertilization significantly (P ≤ 0.05) increased soil organic carbon (SOC), soil organic nitrogen (SON), SCE, moisture, microbial biomass C, and dehydrogenase activity, whereas decreased the SOC/SON ratio after 10 years, which also approached closer to NF. However, only the plots under 10 years of organic fertilization showed SCE significantly (P ≤ 0.05) similar to NF. It indicates that long-term organic fertilization is required for the improvement in soil properties. SCE showed a significantly (P ≤ 0.05) higher value (on average, by 61%) in OM10 site as compared to OM1. However, SCE on unit C basis (SCER) showed no change (P > 0.05). This increase in SCE after 10 years of organic fertilization might be attributed to the significant (P ≤ 0.05) increase in SOC, soil moisture, microbial biomass C, and dehydrogenase activity. However, no change in SCER after 10 years shows that organic fertilization has possibly been misinterpreted with respect to their impact on soil’s global warming potential. It might be attributed to the C protective nature of the organic fertilization. Overall, our results contradict with the often publicized higher warming potential of the organically amended systems. This indicates that organic fertilization does not increase the soil’s global warming potential, which is often misrepresented because SCE is not observed with respect to the existing SOC content. [ABSTRACT FROM AUTHOR]

Growths of Lyngbya limnetica and Oscillatoria obscura were investigated at varying pH, light intensity, temperature, and trace element concentration with a view to optimize these parameters for obtaining the maximum carbohydrate content. The maximum growth for both strains was obtained at pH 9.0 and temperature 20 ± 3 °C using a light intensity of 68.0 μmol m−2 s−1 with continuous shaking. Growth under the nitrogen starvation condition affected the carbohydrate content more compared to the phosphorus starvation, and maximum concentrations were found as 0.660 and 0.621 g/g of dry biomass for L. limnetica and O. obscura, respectively. Under the optimized nitrogen-rich conditions, the specific growth rates for the two strains were found to be 0.187 and 0.215 day−1, respectively. The two-stage growth studies under nitrogen-rich (stage I) followed by nitrogen starvation (stage II) conditions were performed, and maximum biomass and carbohydrate productivity were found as 0.088 and 0.423 g L−1 day−1 for L. limnetica. This is the first ever attempt to evaluate and optimize various parameters affecting the growth of cyanobacterial biomass of L. limnetica and O. obscura as well as their carbohydrate contents. [ABSTRACT FROM AUTHOR]

Mathematical modeling of a phase inversion membrane was studied to predict the morphology. The effect of different concentrations of TiO2 nanoparticles on the thermodynamic and kinetic properties of polyvinylidene fluoride (PVDF) membrane casting solutions was investigated. The addition of green synthesized TiO2 increases the viscosity, and a sufficient amount results in the formation of two phases. Thermodynamics enhances the demixing rate, whereas kinetics delays the demixing rate; this trade-off between thermodynamic and kinetic parameter will affect the membrane morphology. A quadratic phase diagram for PVDF/ TiO2/solvent/Water system was drawn experimentally at different concentrations of TiO2 using a new method. Synthesized membranes were characterized by the contact angle, porosity, and permeability. Surface morphologies at different compositions were also examined using High Resolution scanning electron microscope (HRSEM). At TiO2 concentration of 2 wt% in the polymer casting solution, thermodynamics parameter dominates kinetics parameter; thus, maximum porosity with enhanced permeability was achieved experimentally. The importance of thermo-kinetic parameters was further assessed using response surface optimization. The study suggested an optimum value of 2.165% of weight% TiO2 at 5.125 pH giving excellent agreement to the experimental data. [ABSTRACT FROM AUTHOR]

In this work, biodegradable composite were prepared using banana pseudostem fibre and polyvinyl alcohol (PVA) matrix along with plasticizers and cross linkers in form of blended films of different compositions by solution casting process. The effect of composition on the structure and properties of the resulting films were investigated. OH groups on banana fibre and PVA formed hydrogen bonding interactions, which could improve the compatibility of the two components. With the increase of banana fibre weight percent, the degree of crystallinity of PVA component decreased. The tensile strength and elongation at break decreased with increasing content of banana fibre. However, at 20% banana fibre content, the flexibility of the blend films was still high, with the elongation at break more than 100% and tensile strength of 30.8 MPa, which was near to the commonly used LDPE package films. Composite films were permeable to water, but at the same time able to maintain consistency and composition upon drying. Chemical crosslinking by citric acid and glutaraldehyde, between banana pseudostem fibre and PVA, all of which are hydroxyl functionalized, improved water resistance in films. Composite films with alkali treated banana pseudostem fibres had maximum tensile strength of 34.2 MPa and least water uptake of 60% only. [ABSTRACT FROM AUTHOR]