Blue-shifting H-bonded (C–D···O) complexes between CDCl3 and CH3HCO, (CH3)2CO, and C2H5(CH3)CO, and red-shifting H-bonded (C–D···S) complexes between CDCl3 with (CH3)2S and (C2H5)2S have been ...identified by Fourier transform infrared spectroscopy in the gas phase at room temperature. With increasing partial pressure of the components, a new band appears in the C–D stretching region of the vibrational spectra. The intensity of this band decreases with an increase in temperature at constant pressure, which provides the basis for identification of the H-bonded bands in the spectrum. The C–D stretching frequency of CDCl3 is blue-shifted by +7.1, +4, and +3.2 cm–1 upon complexation with CH3HCO, (CH3)2CO, and C2H5(CH3)CO, respectively, and red-shifted by −14 and −19.2 cm–1 upon complexation with (CH3)2S and (C2H5)2S, respectively. By using quantum chemical calculations at the MP2/6-311++G** level, we predict the geometry, electronic structural parameters, binding energy, and spectral shift of H-bonded complexes between CDCl3 and two series of compounds named RCOR′ (H2CO, CH3HCO, (CH3)2CO, and C2H5(CH3)CO) and RSR′ (H2S, CH3HS, (CH3)2S, and (C2H5)2S) series. The calculated and observed spectral shifts follow the same trends. With an increase in basicity of the H-bond acceptor, the C–D bond length increases, force constant decreases, and the frequency shifts to the red from the blue. The potential energy scans of the above complexes are done, which show that electrostatic attraction between electropositive D and electron-rich O/S causes bond elongation and red shift, and the electronic and nuclear repulsions lead to bond contraction and blue shifts. The dominance of the two opposing forces at the equilibrium geometry of the complex determines the nature of the shift, which changes both in magnitude and in direction with the basicity of the hydrogen-bond acceptor.
Cotton is the most popular natural fiber used in apparel industry world over. Although cotton is cultivated in approximately 2.4% of the world's arable land, it accounts for 24% of the world's ...insecticide market. Industrial hemp is considered as the most sustainable raw material as substitute of cotton in textile industry. However, there are several challenges associated with hemp processing as the fiber is coarse, stiff and it has comparatively poor spinnability particularly when 100% hemp is processed in ring spinning system. The purpose of this paper is to investigate the aesthetic and low-stress mechanical properties, and handle value of the plain woven hemp-blended cotton fabrics. The 16Ne and 30Ne linear density compact and ring yarns were produced and were used to manufacture plain woven suiting and shirting fabrics, respectively. Crease recovery angle, pilling, tear and tensile strength, and handle value of the fabrics were determined.
Fabric tear strength is an important parameter in textile materials since it is linked to the fabric's life. When it comes to bed sheets, a consumer's main concerns are mechanical comfort and ...durability. The fabric's tear strength has a direct impact on its durability. In this study, a novel algorithm was developed using machine learning based neural network approach taking fabric parameters as input and warp and weft tear strength as output. Different state-of-the-art algorithms were used among which the XGboost model (Extreme Gradient Boosting) gave the best results. The training accuracy of the machine learning model was approximately 99.99% and mean absolute error was 0.61 for the weft model and 1.78 for the warp model. Correlation between various fabric parameters and tear strength was determined. The model has the potential to be beneficial to textile industries since it can reduce the number of production efforts for a high-quality bed sheet fabric, saving both time and money. Artificial neural networks are used to forecast fabric performance in textile manufacturing. Tests show that these artificial neural networks are good at predicting future difficulties.
Blue-shifting H-bonded complexes between CHCl
and CH/D
CN have been identified by Fourier transform infrared spectroscopy in the gas phase at room temperature. The change in FTIR peak intensity of ...the mixture of the two components as a function of temperature and composition provides the basis for identification of the H-bonded band in the infrared spectrum. On complex formation with CH
CN and CD
CN, the C-H stretching frequency of CHCl
shifts to the blue by +8.7 and +8.6 cm
, respectively. The molecular electrostatic potential calculation at the MP2/6-311++G** level has been used to arrive at the geometry of the complex. It has been reported in the literature that CHCl
and CH/D
CN form red-shifting H-bonded complex in Ar matrix. The red shifting has been verified by doing ab initio calculations in the presence of Ar atoms, which has been attributed to the matrix effect at low temperature. The interaction of Ar with CH
CN makes the CH
CN more basic and as a result it becomes better hydrogen bond acceptor and causes red shift. The potential energy scans and NBO analysis of the Cl
CH···NCCH
complex have been compared with those of F
CH···NCCH
and Cl
CH···NH
complexes. The change in electron density of the CHCl
as a function of C-H···N distance shows that the approach of CH
CN to CHCl
induces a shift in electron density from the H atom to the Cl atoms of CHCl
which leads to C-H bond contraction and blue shifting of C-H stretching frequency. However, in the complex Cl
CH···NH
, where frequency shift to the red is reported, charge transfer and electrostatic interaction dominate.
Fiber-reinforced composites are the materials of choice in numerous advanced applications in the fields such as automotive, aerospace, and marine as compared to conventional engineering materials. In ...this context, the influence of reinforcement architecture on the static mechanical performance of composite leaf spring was investigated. Reinforcement in the form of E-Glass chopped fibers, uni-directional (UD), bi-directional (2D) woven, and 3D orthogonal woven preforms were used to prepare composite leaf spring with identical fiber volume fraction and composite processing conditions. Composite leaf springs were analyzed for tensile properties, load-deflection behavior, strain rate sensitivity, hysteresis behavior (Damping), and relaxation behavior. Performance of 3D woven-based composite leaf spring was significantly better than chopped, UD, and 2D counterparts in terms of energy absorption, strain rate sensitivity, hysteresis damping (energy dissipation), and relaxation behavior. Overall 3D composite leaf spring shows a high potential for leaf spring application.
The mechanical activation of fly ash was carried out using ball milling to promote adhesion with epoxy. The 5 h of wet pulverization was found to result into particle size of less than 500 nm. The ...obtained nanoparticles were incorporated into epoxy to prepare three layered laminated composite of glass fabrics. The results revealed substantial improvement in mechanical properties of nanocomposites as compared to neat and unmilled fly ash composites. Moreover, the storage modulus exhibited 85.71, 38.09, 104.76 and 80.95% increment over neat composites for 1, 3, 5 and 10 wt% of activated fly ash at 200 °C.
Aquaculture is emerging as one of the most viable and promising enterprises for keeping pace with the surging need for animal protein, providing nutritional and food security to humans, particularly ...those residing in regions where livestock is relatively scarce. With every step toward intensification of aquaculture practices, there is an increase in the stress level in the animal as well as the environment. Hence, disease outbreak is being increasingly recognized as one of the most important constraints to aquaculture production in many countries, including India. Conventionally, the disease control in aquaculture has relied on the use of chemical compounds and antibiotics. The development of non-antibiotic and environmentally friendly agents is one of the key factors for health management in aquaculture. Consequently, with the emerging need for environmentally friendly aquaculture, the use of alternatives to antibiotic growth promoters in fish nutrition is now widely accepted. In recent years, probiotics have taken center stage and are being used as an unconventional approach that has numerous beneficial effects in fish and shellfish culture: improved activity of gastrointestinal microbiota and enhanced immune status, disease resistance, survival, feed utilization and growth performance. As natural products, probiotics have much potential to increase the efficiency and sustainability of aquaculture production. Therefore, comprehensive research to fully characterize the intestinal microbiota of prominent fish species, mechanisms of action of probiotics and their effects on the intestinal ecosystem, immunity, fish health and performance is reasonable. This review highlights the classifications and applications of probiotics in aquaculture. The review also summarizes the advancement and research highlights of the probiotic status and mode of action, which are of great significance from an ecofriendly, sustainable, intensive aquaculture point of view.
Composites are popular in construction engineering due to their low water absorption, good chemical and corrosion resistance, lightweight, high specific strength, high specific modulus, and low ...thermal conductivity. The flame retardancy (FR) of composite materials has increasingly become the focus of attention in the field of construction engineering. With growing awareness of personal and property safety, a wide range of flame-retardant composites has been developed over the years through research and development. The FR of an unmodified polymer composite is not optimal, and therefore, many innovative methods for making more advanced flame-retardant materials have been developed. The aim of this review is to provide detailed literature on flame-retardant composites. The structure of this paper consists of evolution of flame-retardant materials, their manufacturing techniques, flame-retardant composites, their properties and characterization, applications, and challenges related to of FR composites. The primary focus of this review is to analyze the mechanism of fire retardancy and to summarize the preparation of flame-retardant polymer materials by adding various flame-retardant agents.
Graphical abstract
Fabric hand is the quality of a fabric assessed by the reaction obtained from the sense of touch. Fabric hand is the person's estimation when feeling fabrics between fingers and thumb. Assessment of ...a textile material obtained from the sense of touch is an essential consideration in fabric development and marketing. The aim of this review is to provide detailed literature on fabric hand dating back to 1930. The structure of the article consists of the evolution of fabric hand research, its definition given by various researchers, subjective and objective evaluation, artificial neural network (ANN) modeling, instruments used to evaluate low-stress mechanical properties, the relationship between physical properties and fabric hand, applications of fabric hand, the extensive literature on all the existing Kawabata equations for conventional as well as specialty textiles. The review presents a computational approach by the authors to predict the fabric hand of specialty fabrics like automotive textiles, denim, bed linen, etc.
