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Effect of Titanium Oxide on Hydrogen Peroxide Generation in Plasma-Activated Water
No full textH2O2 plays an important role in various applications of disinfection and water treatment. In addition to conventional methods, H2O2 can be generated in plasma-activated water using cold plasma. Although plasma-activated water contains H2O2, its concentration is typically low. It can be increased with the help of a catalyst like titanium oxide. In this study, titanium oxide powder was added to plasma-activated water to understand its effect on H2O2 concentration. The various parameters like treatment time (up to 30 min), TiO2 weight (2–6 g), and transformer power (70 W, 90 W, and 150 W) were used. Results show that the H2O2 concentration increases with treatment time, transformer power, and TiO2 weight. No significant increase in H2O2 concentration was observed beyond 30 minutes of treatment time with 90 W and 150 W transformers. These findings highlight the potential of TiO2-assisted plasma-activated water for water treatment and disinfection applications
Utilization of Spent Coffee Grounds, Waste Glass, and Clay as Raw Materials for Flooring Tiles
No full textThe imperative confronting the national construction industry lies in the innovation of materials, harmonizing the delicate balance between resource utilization, energy efficiency, and economic accessibility. This study aimed to utilize Spent Coffee Grounds, Waste Glass, and Clay as modified unglazed ceramic tiles. The study focused on determining each raw material's physical and chemical characteristics by testing it using grain size analysis for physical traits and Fourier transform infrared spectroscopy (FT-IR) for chemical characteristics. The study tested the optimum mixture of Spent Coffee Grounds, Waste Glass, and Clay using the ASTM standard for flexural testing, ASTM C1505. Upon comparison, the control group, comprised of 50% clay, 25% feldspar, and 25% sand, exhibited an average breaking strength of 704.53 N and a modulus of rupture of 10.568 MPa, derived from five samples. Remarkably, T3, comprised of 15% Spent Coffee Grounds, 25% Waste Glass, and 60% clay, showcased superior performance, yielding a breaking strength of 1077.3 N and a modulus of rupture of 16.16 MPa. This study focused only on testing and identifying the physical and mechanical properties of Spent Coffee Grounds, Waste Glass, and Clay. The experimental data strongly suggests that mixtures incorporating Spent Coffee Grounds and Waste Glass exhibit superior mechanical properties compared to the control group
Influence of Tank Geometry on Seismic Performance and Cost of RCC Overhead Water Tanks in Indian Seismic Zones
No full textOverhead water tanks made of reinforced cement concrete (RCC) are critical to municipal infrastructure and are at great risk for seismic forces because of their elevated heights and the large mass of the liquid. This study offers a zone-wise comparative design and economic analysis of three common tank shapes, a circular, rectangular, and Intze configured to hold 500 kL. Each tank shape was modelled and analyzed in Staad.Pro, and the resulting seismic performance was assessed using the Response Spectrum Method based on IS 1893 (Part 2): 2014 in all Indian Seismic Zones II, III, IV, and V. The parameters of interest were the base shear, top displacement, material quantities of concrete and steel, and total cost of construction. The results showed that circular tanks performed best in reduced seismic loads in Zone II originations with loads symmetrically dispersed along both axes, while Intze tanks performed best in Zones IV-V, showing reduced displacement and cost, along with limits of horizontal force. Rectangular tanks showed a tendency for poorer earthquake performance and more material use, but are common due to site constraints in urban areas. The conclusions indicate the utility of a geometrically based design method whereby an Intze tank can be built in Zones IV-V, while Circular tanks provide adequate seismic safety and economy in Zones II-III. Recommendations are provided for future development of earthquake-resistant water infrastructure, and its advantages for municipalities in India
Employing Green Technology System in calibrating Eco-Marketing strategy of grape growing companies: Transparent and Controlled use of Green Chemicals
No full textDue to the complexity of the vineyard ecosystem, a growing number of eco-certified inputs has been integrated into a framework of sustainable agricultural practices. This research is aimed at developing a hybrid framework that can be used to predict the eco-label readiness of a certain vineyard and provide guidance about the ecological indicators that should be prioritized in it as well as to find ways to increase the marketing effectiveness. Secondly, the sample of vineyards (n = 50) was divided into three groups—early, mid-season and late ripening varieties—for the analysis of a significant difference observed between and within groups, in terms of the effects of sensor-calibrated inputs on eco-performance indicators. In the second phase, the structural analysis focused on the relationship between eco-performance indicators and its outcomes (eco-label readiness, both direct and indirect effects). Then, the regression analysis and structural equation modeling showed that out of all examined eco-performance results, the timing of the chlorophyll decline, the behaviour of the sugar accumulation under controlled application, and the stability of the eco-readiness over time contributed to the total variance of eco-performance. Yet, the results confirm our assumption that an improvement in sensor calibration and nutrient scheduling is also necessary, particularly in the eco-label certification process of vineyards. The methodology can be used to make informed decisions both about the operational strategies for increasing the eco-marketing performance and the selection of inputs that should be applied in the vineyard
Waste Heat Driven Vapour Absorption Refrigeration System for Two-Wheelers Using LiBr-H
No full textWith rising urban temperatures and the lack of climate control in two-wheelers, riders particularly in the developing world experience high thermal discomfort. Conventional vapour compression-based systems are not feasible for two-wheelers because of space and power constraints. In spite of widespread work on automotive waste heat recovery, very little work has been done on rider-centric, compact, and sustainable two-wheeler cooling systems. This work fills that void by presenting a new vapour absorption refrigeration system (VARS) using waste energy from a two-wheeler's exhaust gases. The system uses a lithium bromide-water (LiBr-H2O) couple to provide localized cooling through a wearable jacket-type evaporator. A thermoelectric generator (TEG) additionally adds self-sufficiency by driving the VARS pump, rendering the system almost energy-autonomous in nature. Thermodynamic analysis indicates the maximum COP of 0.944 and practical COP of 0.7365. This paper offers a sustainable and innovative method for enhancing rider comfort without sacrificing the performance of vehicles, offering energy-efficient and climate-resilient transport solutions
Combined machine learning approaches to predict thermal conductivity for liquid mixtures
No full textThe application of Machine Learning (ML)-based techniques was explored to create a fully predictive framework for estimating the thermal conductivity of multi-component mixtures containing hydrocarbons and oxygenated compounds. The study followed these steps: (i) three datasets were constructed using experimental thermal conductivity data for both pure compounds and binary mixtures available in the literature, (ii) Symbolic regression was then applied to generate mixing rules considering five independent data manipulation strategies, (iii) new quantitative structure-property relationship (QSPR) models were developed and benchmarked against work previously published in the literature, and then (iv) QSPR models were used to power mixing rules generated with symbolic regression to predict thermal conductivity values of binary mixtures. A mixing rule was then designed to propose a potential extension to multi-component – two or more components – mixtures. Validation of the latter mixing rule powered with QSPR predictions was performed considering a set of ternary and quaternary mixtures. Finally, the approach was applied to predict the thermal conductivity of four jet fuel samples at different temperatures and atmospheric pressures, resulting in a mean absolute error of 2.9%. Performed comparative analysis confirmed that the developed methodology is effective across a wide range of liquid hydrocarbon and oxygenated mixtures
Data-driven models for the operation of a dynamic primary standard based on permeation
No full textFor the preparation of calibration gas mixtures with low levels of reactive compounds, the permeation method as described in ISO 6145-10 is excellently suited. In the past years, it has proved to be useful for developing primary standards for key impurities in hydrogen, such as ammonia, hydrogen fluoride and hydrogen chloride. Using an automated balance to measure the mass loss of the permeation tube, large volumes of data are gathered, from which the permeation mass flow rate is calculated. The residuals of traditional simple straight-line regression show patterns which deserve further attention. They suggest that the current approach may underrate the uncertainty associated with the permeation rate. The permeation system is operated with a dilution system using thermal mass flow controllers. These produce large volumes of data as well, which are processed to obtain a mass flow rate and associated uncertainty. It is shown how time series models enable assessing correlations in the data from the magnetic suspension balance and the thermal mass flow controllers. These data-driven models provide a better description of the features of the data and thereby provide more realistic estimates of the mass flow rates and associated uncertainties. The time series analysis reveals that the permeation data are quite heavily autocorrelated, whereas the data from the thermal mass flow controllers are uncorrelated
Violent mergers revisited: The origin of the fastest stars in the Galaxy
No full textBinary systems of two carbon-oxygen white dwarfs are one of the most promising candidates for the progenitor systems of Type Ia supernovae. Violent mergers, where the primary white dwarf ignites when the secondary white dwarf smashes into it while being disrupted on its last orbit, were the first double degenerate merger scenario proposed that ignites dynamically. However, violent mergers likely contribute only a few percent to the total Type Ia supernova rate and do not yield normal Type Ia supernova light curves. Here we revisit the scenario, simulating a violent merger with better methods and, in particular, a more accurate treatment of the detonation. We find good agreement with previous simulations but with one critical difference: The secondary white dwarf being disrupted and accelerated towards the primary white dwarf and impacted by its explosion does not fully burn, and its core survives as a bound object. The explosion leaves behind a 0.16 M⊙ star travelling 2800 km/s, making it an excellent (and so far the only) candidate to explain the origin of the fastest observed hypervelocity stars. We also show that before the explosion, 5 × 10−3 M⊙ of material predominantly consisting of helium, carbon, and oxygen had already been ejected at velocities above 1000 km/s. Finally, we argue that if a violent merger made the hypervelocity stars D6-1 and D6-3 and violent mergers require the most massive primary white dwarfs in binaries of two carbon-oxygen white dwarfs, there has to be a much larger population of white dwarf mergers with slightly lower mass primary white dwarfs. Because this population likely represents ≫10% of the Type Ia supernovae rate, it can essentially only give rise to normal Type Ia supernovae
Distinguishing ram pressure from gravitational interactions: Applying the size-shape difference method to real galaxies
No full textContext. In dense environments, mechanisms such as ram pressure stripping (RPS) and gravitational interactions can induce the formation of similar morphological features in galaxies that are only distinguishable through a detailed study of the stellar properties. While RPS affects recently formed stars through the displacement of the gas disk from which they are formed, gravitational interactions perturb stars in a similar way.
Aims. We present the first observational test of the size-shape difference (SSD) measure. This novel approach, which was originally designed and validated for simulated galaxies, quantifies morphological differences between young and intermediate-age stellar populations to distinguish RPS from gravitationally interacting galaxies.
Methods. We analyzed 67 galaxies from the GASP survey using spatially resolved star formation history derived from the SINOPSI