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Three types of nonwoven structures, viz. one mono-component (100 % cotton) and two bi-components (homogeneously dispersed fibres and layer-wise assembled fibres) have been prepared and then evaluated for absorption performance. The addition of superabsorbent (SAF) fibres into the nonwoven structure marginally improves the absorption capacity of the homogeneously blended structure in comparison to the 100 % cotton web. The liquid (synthetic urine) retention of the cotton web is found to vary between 45 % and 65 %, depending upon the external pressure. The SAF, however, increases the retention capacity significantly. Amongst all the structures, the retention of layered structure is found to be superior to the rest. [ABSTRACT FROM AUTHOR]

In this study, moisture management properties of knitted fabrics from Eli-Twist polyester and cotton yarns have been investigated. A comparative analysis with knitted fabrics from conventional ring-spun, siro-spun and compact yarns has also been made to assess its suitability. It is observed that polyester and cotton fabrics made from Eli-Twist yarn show very good permeability and moisture management characteristics. [ABSTRACT FROM AUTHOR]

The isotopic values of rainfall in the southern parts of India exhibit strong seasonality. Such a contrast in isotopic values arises mainly due to the seasonal reversal of the monsoon winds. During the summer monsoon season, moisture is primarily transported from the Arabian Sea, while during the winter, it is sourced mainly from the Bay of Bengal. Additionally, atmospheric processes contribute to these differences. We collected precipitation samples from a southern Indian site and two neighboring island locations to study their isotopic characteristics from intra‐seasonal to seasonal timescale. Oxygen isotopes in the marine environment seem to respond differently to the surface and tropospheric temperature than their counterparts from the land region. The seasonal isotopic gradient in the marine environment appears to be modulated by the tropospheric temperature anomaly. Oxygen isotopic values showed a strong association with the Webster‐Yang monsoon index. Two distinct clusters were formed when the oxygen isotopes were plotted against the above‐mentioned monsoon index. The formation of these clusters indicates the precipitation isotopes' response to moisture dynamics, which significantly change during the transition phase of the southwest to the northeast monsoon. Finally, we examine the potential of the precipitation isotopic records in studying the monsoon process, viz, the use of precipitation isotopes in characterizing the thermodynamical properties of the atmosphere and estimating the summer monsoon withdrawal phase. Plain Language Summary: Atmospheric parameters such as temperature, rainfall, humidity, wind circulation, etc., vary significantly across the seasons. Such kind of variations or the seasonality also varies from place to place. The heavy to light isotopic distributions of hydrogen and oxygen atoms in atmospheric water also differ considerably from summer to winter, termed isotopic seasonality (defined here as Δδ18O). This feature manifests well in southern peninsular India, wherein the summer monsoon season is characterized by higher isotopic values relative to the winter season. Monsoon circulation is south‐westerly during the summer and north‐easterly during the winter. These two opposing circulation regimes cause isotopic seasonality in south peninsular India. Meteorological parameters such as rainfall, wind speed, etc., display sharp changes during the summer monsoon onset in early June. But they change rather slowly during the transition from summer to winter monsoon season around late September–early October. As a result, the estimation of the summer monsoon withdrawal date may have considerable uncertainty. It is proposed that applying the isotopic technique may be potentially helpful in reducing such an uncertainty. Key Points: Precipitation isotopic time series at the northern Indian Ocean reveal strong seasonality, driven by monsoon thermodynamicsTwo well‐defined clusters are formed when δ18O is plotted against the Webster‐Yang circulation indexThe formation of clusters is indicative of isotopic response to moisture dynamics [ABSTRACT FROM AUTHOR]

The nonlinear convectively coupled character of the summer monsoon intraseasonal oscillation (ISO) that manifests in its event-to-event variations is a major hurdle for skillful extended-range prediction of the active/break episodes. The convectively coupled character of the monsoon ISO implies that a particular nonlinear phase of the precipitation ISO is linked to a unique pattern of the large-scale variables. A methodology has been presented to capture different nonlinear phases of the precipitation ISO using a combination of a sufficiently large number of dynamical variables. This is achieved through a nonlinear pattern recognition technique known as self-organizing map (SOM) involving six daily large-scale circulation indices. It is demonstrated that the nonlinearly classified states of the large-scale circulation isolated at the SOM nodes without involving any information on rainfall are strongly linked to different phases of evolution of the rainfall ISO, including the active and break phases. While a lower SOM classification involving 9 different states identify the composite phases of the rainfall ISO, a higher SOM classification involving 81 states can identify different shades of composite phase of the rainfall ISO. The concept of isolating the nonlinear states, as well as the technique of doing so, is robust as almost identical phases of precipitation ISO are identified by the large-scale circulation indices derived from two different reanalysis datasets, namely, the 40-yr ECMWF Re-Analysis (ERA-40) and the NCEP--NCAR reanalysis. The ability of the SOM technique to isolate spatial structure and evolutionary history of nonlinear convectively coupled states of the summer monsoon ISO opens up a new possibility of extended-range prediction of summer monsoon ISO. This knowledge is used to develop an analog technique for predicting different phases of monsoon ISO. Skillful four-pentad lead prediction of rainfall over central India is demonstrated with the model using only large-scale circulation fields. A major strength of the model is that it can easily be used for real-time extended-range prediction of monsoons.

A simple integrated hydrogen sensor using Pd-Au alloy/air based one dimensional photonic crystal with an air defect layer is theoretically modeled. Structural parameters of the photonic crystal are delicately scaled to generate photonic band gap frequencies in a visible spectral regime. An optimized defect thickness permits a localized defect mode operating at a frequency within the photonic band gap region. Hydrogen absorption causes modification in the band gap characteristics due to variation of refractive index and lattice parameters of the alloy. As a result, the transmission peak appeared due to the resonant defect state gets shifted. This peak shifting is utilized to detect sparse amount of hydrogen present in the surrounding environment. A theoretical framework is built to calculate the refractive index profile of hydrogen loaded alloy using density functional theory and Bruggeman's effective medium approximation. The calculated refractive index variation of Pd3Au alloy film due to hydrogen loading is verified experimentally by measuring the reflectance characteristics. Lattice expansion properties of the alloy are studied through X-ray diffraction analyses. The proposed structure shows about 3 nm red shift of the transmission peak for a rise of 1% atomic hydrogen concentration in the alloy. [ABSTRACT FROM AUTHOR]

Cotton fibres have been used in many absorbent products. A porous structure is most conducive to absorbing liquid. More is the porosity better would be the absorbent capacity. However, a porous fibrous structure is structurally fragile and can easily collapse during the absorbing process leading to changes in porosity, nature of pore structure and pore size distribution. The structural rigidity is influenced by fibre fineness and degree of mechanical bonding between the fibres. The absorbency characteristics and structural collapsing possibility of nonwoven fabrics made from very coarse and fine cotton fibres have been investigated using synthetic urine. It has been shown that the absorption capacity rises phenomenally, once the porosity crosses the value of 0.97. All nonwoven have been found to collapse laterally during absorption process, leading to lowering of absorption capacity especially in nonwovens consisting of fine fibres (3 micronaire). Nonwovens made from coarser fibres (6 micronaire) showed both higher absorption capacity and rate in comparison to those made from finer fibres (3 micronaire). [ABSTRACT FROM AUTHOR]

An attempt has been made to investigate the migration characteristics in polyester and cotton Eli-Twist yarn. Three different counts (39.4, 29.5 and 23.6 tex) from each composition have been produced maintaining 40 twist factor for each. For comparative study, the 29.5 tex yarn of two compositions from cotton and polyester are produced on Eli-Twist and Siro spinning systems. The mean fibre position for Eli-Twist polyester yarn is found to be less than that of cotton yarn. Both root mean square deviation and mean migration intensity in Eli-Twist yarn are found to be higher, while mean fibre position is lower as compared to Siro yarn. [ABSTRACT FROM AUTHOR]

A cotton garment is preferred in normal use due to cotton's moisture absorbing properties and comfort. But this absorbed moisture is not transported away from skin for spreading and evaporation to outer layer of fabric making garment wet and causing fabric cling. The garmentskin microclimate has a large moisture gradient when wearer moves between environments with difference in relative humidity which causes a chilling feeling and negatively affecting thermophysiological comfort of wearer. The objective of this work is to improve sensible perspiration transport property of cotton fabric by developing a knitted structure having different wetting properties on inner (skin side) and outer face of fabric This was achieved by applying a water repellent finish at the yarn stage to ultimately modify the wetting behavior of single jersey and plated single jersey cotton knits to enhance their liquid moisture transport properties. [ABSTRACT FROM AUTHOR]