Optimum Percentage Research Articles

Performance assessment of surface modified natural fibre using NaOH in composite concrete

Abaca fiber degradation in concrete owing to its alkaline nature decreases the strength of concrete. This research focuses on overcoming the degradation by alkaline treatment with sodium hydroxide (NaOH) to improve fiber performance. This study was completed with the extraction process of fiber, mechanical properties, micro-structural analysis of composite fiber concrete for both M30 and M40 grades, and durability performance if the fiber content, aspect ratio of fiber and molarities of Sodium Hydroxide were optimized using splitting tensile strength of the concrete matrix and it was found that the optimum percentage of fiber content was 1% at 12% alkali treatment. The composite concrete has achieved an increase of 2700 to 3100 kg m−2 in split tensile strength with treated abaca fibers compared to untreated fiber concrete. In addition, treated abaca fiber concrete provides better performance in mechanical and durability studies. The binding nature of fiber concrete is better than that of conventional concrete, which is evidenced in microstructural analysis. This study ultimately concluded that the treated abaca fiber composite concrete is a better alternative to commercially available untreated abaca fibers and other natural fibers.

Durability studies on concrete with partial replacement of cement and coarse aggregate by seashell waste

A sea animal creates a hard, protective outer layer called a seashell. Empty seashells frequently wash ashore, and beachcombers find them. This marine byproduct can be used in concrete as a replacement for cement or aggregate. This study describes the use of seashell products as a partial substitute for cement and coarse aggregate in the production of sustainable concrete to evaluate the durability characteristic of concrete. Various percentages of seashell trash were substituted for the cement and coarse aggregate by weight of the concrete. Water absorption, sorptivity and rapid chloride permeability on the seashell concrete were performed experimentally. Additionally, sulphate and alkaline attack as marine environment were studied for seashell concrete specimens immersed in chemical solution for 90 days. The seashell concrete's durability traits were contrasted with those of a control specimen. It is concluded that the optimum percentage of replacement of cement and coarse aggregate by seashell powder (SP) and seashell aggregate (SA) are 10% and 20% respectively to obtain durable concrete.

Modifying the active phase structure of Ni2P/Al2O3 by Ga introduction for improved hydrodesulfurization of diesel

Modifying the structure of active phase is an effective protocol to improve the catalytic activity of hydrodesulfurization (HDS) catalyst. Here, a variety of mesoporous GaAlOx supports with various Ga doping amount were synthesized by a facile hydrothermal strategy. The corresponding Ni2P supported catalysts were fabricated via a conventional impregnation and temperature-programmed reduction method, and their catalytic performances for 4,6-DMDBT HDS were examined. The experimental analyses show that the introduction of Ga substantially influences the geometric and electrical structure of Ni2P active phase on Ni2P/GaAlOx catalysts. The metal-support interaction is effectively abated with the elevation of Ga doping amount, thereby increasing the d-electron density of Ni species and boosting the pre-hydrogenation (HYD) route, thereupon enhancing the HDS performances of corresponding Ni2P/GaAlOx catalysts. Therein, Ni2P/GaAlOx-0.50 exhibits the highest activity with 70.1% 4,6-DMDBT conversion because of the optimal morphology and percentage of active phase, as well as distinguished redox and acid property. Further increasing the Ga loading, however, inhibits the HDS activity of Ni2P/GaAlOx-1.0 catalyst due to the decrease in the fraction and dispersion of active phases. Therefore, this work may shine light on the understanding of structure–activity of HDS catalyst and thereafter the preparation of HDS catalysts with high efficiency in future.

Qualitative Evaluation for Asphalt Binder Modified with SBS Polymer

Solutions for safer, more durable infrastructure are required in light of increasing traffic and severe weather in Iraq. The most significant road conservation and maintenance challenges are the pavement's low resistance to dynamic loads and short service life. As a result, vast sums of money are spent annually to enhance the road service capacities in Iraq. Thermoplastic electrometric polymers for bitumen modification create long-lasting, cost-effective roadways. This study aims to determine how the mechanical properties of neat asphalt binder change when styrene butadiene styrene (SBS) is added as a modifier. The current research investigates adding three percentages of SBS (3, 5, and 7% of the weight of bitumen). Both neat and polymer-modified bitumen (PMB) were subjected to a series of physical laboratory and Superpave tests, including a dynamic shear rheometer tester (DSR) and a storage stability test. In addition, a chemical analysis test was conducted to identify any change in the neat binder chemical composition due to the addition of SBS polymer. The results indicated that 5% of SBS polymer was the optimum addition percentage to the local asphalt in Iraq. Additionally, it reduced the susceptibility of bitumen to temperature changes and enhanced its characteristics in all laboratory tests. The obtained PMB significantly improved rutting and fatigue factors compared to the neat asphalt binder. Based on the DSR tester and the storage stability test, the ratio of 5% SBS met the requirements of class PG76-10, used in the central and southern governorates of Iraq. Using SBS polymer on the surface course in Iraq reduces road damage due to the scorching summer sun, reduces the likelihood of rutting and fatigue cracking, and works well in hot regions, resulting in roads that last longer, provide comfortable riding, and require less maintenance.

An exploratory look at the role of ownership in initial coin offerings (ICO): Different audiences and ICO success

Initial coin offering (ICO) is a Web-3 based financing method for ventures, which allows them to use digital assets (e.g., tokens) to raise capital. During an ICO, the entrepreneur has control on ownership; they can choose to issue a very small number of tokens which would allow them to keep “their skin in the game” and retain ownership, or issue all the tokens they hold, which would distribute ownership to investors and have a community-decentralized orientation. While previous literature has identified several factors of ICO success, they have not delved into the role of ownership in ICO success. In this study, we explore whether retaining or distributing ownership during an ICO is more beneficial for raising capital. We find a two-pronged explanation. When looking at ICOs maintaining a higher level of ownership, entrepreneurs are catering to corporate-market logic investors, and we see a U relationship where the optimal percentage in which the entrepreneurs show they have skin in the game at the same time as giving enough to investors. But then, there are ICOs distributing most of its ownership in which entrepreneurs are attracting community-oriented investors, and as such, the higher the distribution the higher the investment. We propose that this is related to how there are different investors audiences’ that will value different practices and ideals and choose differently on what types of projects to invest in. Our research elucidates this new funding source. Nonetheless, future research should investigate these exploratory findings.

Formation and stability of emulsion in the presence of nano particles in the modified smart aqueous phase: Effect of ultrasonic, salt, and surfactant

Synergistic effects of nanoparticles (NPs) and smart water flooding are new methods for enhanced oil recovery (EOR). One of the vital issues, in this case, is the formation and stability of emulsion. Therefore, investigating the role and performance of NPs and ions during the processes of EOR, which are based on smart water injection and natural reservoir production, is of significant importance. Previous studies have investigated various factors (i.e., compounds present in oil and water) that affect emulsion stability mainly at ambient temperatures. In this research, the effect of various factors, including the effect of surfactants, salts, and NPs, on the dynamics and thermodynamics of this phenomenon, has been studied through the visual analysis of emulsion droplets under high pressure (HP) and high-temperature (HT) conditions. Based on the results obtained from the experiments, the rate of formation and stability of emulsions increases by increasing the pressure, and after a certain pressure level, it decreases. On the other hand, in general, the rate of emulsion stability follows a decreasing trend by increasing the system temperature. Additionally, in this study, three salts, namely MgCl2, CaCl2, and NaCl, and two surfactants, AOS (alpha olefin sulfonate) and CTAB (cetrimonium bromide), were used. After finding the optimal weight percentage of these salts and surfactants in the formation and emulsion stability, they were combined with nanoparticles of silica oxide in different volume percentages, and the effect of these nanoparticles on the emulsion stability was investigated. The effect of ultrasonication on solutions containing NPs was also investigated from the point of view of emulsion formation and stability. Based on the results obtained, as the power consumption of the ultrasonic device increases to form an emulsion, the rate of rotation for its separation will also increase.

Biochar Coating as a Cost-Effective Delivery Approach to Promoting Seed Quality, Rice Germination, and Seedling Establishment.

The application of high-quality seeds ensures successful crop establishment, healthy growth, and improved production in both quantity and quality. Recently, biochar-based seed coating has been recognized as a new, effective, and environmentally friendly method to enhance seed quality, seedling uniformity, and nutrient availability. To study the impact of biochar coating on the surface mechanical properties of coated seeds, rice emergence and growth, and related physical and physiological metabolic events, laboratory experiments were performed on two water-saving and drought-resistance rice (WDR) varieties (Huhan1512 and Hanyou73) using biochar formulations with varying contents (20%-60%). The results showed that the appropriate concentration of biochar significantly improved emergence traits and seedling performance of the two rice varieties, compared to the uncoated treatment, and that the optimal percentage of biochar coating was 30% (BC30). On average, across both varieties, BC30 enhanced emergence rate (9.5%), emergence index (42.9%), shoot length (19.5%), root length (23.7%), shoot dry weight (25.1%), and root dry weight (49.8%). The improved germination characteristics and vigorous seedling growth induced by biochar coating were strongly associated with higher water uptake by seeds, increased α-amylase activity and respiration rate, and enhanced accumulation of soluble sugar and soluble protein. Moreover, the evaluation results of mechanical properties related to seed coating quality found that increasing the proportion of biochar in the coating blend decreased the integrity and compressive strength of the coated seeds and reduced the time required for coating disintegration. In conclusion, biochar coating is a cost-effective strategy for enhancing crop seed quality and seedling establishment.

Investigation into the Impact of L-Shaped RC Shear Wall Placement with Openings on the Behavior of Medium-Rise Buildings

This article aims to investigate the impact of regular openings in L-shaped reinforced concrete (RC) shear walls located at building corners. A comparison of different buildings and an estimation of the optimal percentage of openings were conducted. To accomplish this, various wall models, with and without openings, underwent numerical simulations using the ETABS program. The research focused on medium-rise ten-story buildings with opening rates of 0%, 15%, 20%, 25%, 30%, and 35% in the X and/or Y direction under high seismic loading conditions (Zone-III) following the Algerian Paraseismic Regulations (RPA 99/version 2003). The findings of this study indicate that openings have a noticeable impact on the overall behavior of buildings and on the shear wall's capacity to withstand earthquakes. However, opening ratios of 20.8%, 30%, and 31.8%, depending on the direction, are considered optimal opening percentages for L-shaped shear walls. These percentages ensure a suitable balance between architectural functionality and the effective structural performance of L-shaped shear walls. Thus, it is important to consider the placement of openings in the design of reinforced concrete structures braced by shear walls.

Investigation on the effect of multiwalled carbon nanotubes in carbon fiber‐reinforced epoxy composites manufactured using vacuum infusion process and hand layup process followed by vacuum bagging

AbstractEpoxy/carbon fiber (CF) composites are widely used for structural applications owing to their exceptional mechanical and physical characteristics. The main aim of this work is to individually analyze the impact of multiwalled carbon nanotubes (MWCNTs) as nanofillers in epoxy/MWCNTs/CF composites prepared by vacuum infusion process (VIP) and hand layup followed by vacuum bagging technique (HLVB). Optimal Manufacturing Strategies were followed at various stages of manufacturing which include the selection of effective dispersion technique for MWCNTs, identification of optimal weight percentage of MWCNTs in epoxy/MWCNTs nanocomposites and preparation of epoxy/MWCNTs/CF composites. For HLVB samples, tensile and flexural strengths increased from 337.5 to 475 MPa and 615.40 to 677.09 MPa. For VIP samples tensile and flexural strengths increased from 371 to 521 MPa and 714.19 to 769.02 MPa. Thermogravimetric analysis (TGA) indicated improvement in the thermal stability of epoxy with the incorporation of MWCNTs/CF and improved weight percentage retention of 84.7% at 375°C. Fracture analysis of the epoxy/MWCNTs/CF composites prepared using VIP were analyzed by FE‐SEM and revealed that constant fiber rupture caused by better interface and improved bridging mechanism eventually led to enhanced mechanical performance. The predominant immediate fracture mechanism of MWCNTs also indicated this improved interfacial interaction.Highlights Pull‐out fracture mechanism was predominantly seen in high viscous epoxy/MWCNTs composites Immediate fracture mechanism of MWCNTs were predominant in low viscous epoxy/MWCNTs sample Constant fiber rupture of VIP samples indicated improved fiber matrix interface Incorporation of MWCNTs showed improved weight percentage retention 0.5 wt% MWCNTs incorporated VIP epoxy/CF composites showed improved performance

Strength and Stiffness Evaluation of a Fiber-Reinforced Cement-Stabilized Fly Ash Stone Dust Aggregate Mixture

The utilization of waste fly ash in road construction is primarily confined to its use in embankment filling or as a stabilizer when combined with lime and cement. Its application in structural pavement layers, such as the base and subbase, faces a challenge due to the high volume of fine particles, which renders it brittle when stabilized. In this study, fly ash was blended with stone dust and aggregated to enhance its gradation. Subsequently, it was stabilized with cement to bolster its strength, rendering it suitable for pavement use. Additionally, polypropylene (PP) fibers were introduced to mitigate the brittleness of the mixture. An extensive experimental investigation was conducted to assess the strength and stiffness properties, including compressive strength, indirect tensile strength, flexural strength, cyclic indirect tensile modulus, and flexural modulus of fiber-reinforced cement-stabilized mixtures of fly ash, stone dust, and aggregate. The experimental results reveal that the addition of PP fibers up to 0.25 wt.% enhances compressive strength, but any further increase in fiber content leads to a reduction in strength. However, indirect tensile strength and flexural strength show improvement, with an increase in fiber percentage up to 0.5 wt.%. It was observed that cement content plays a dominant role in stabilizing these materials. Appropriate relationships have been established between strength and modulus parameters for stabilized mixtures. Based on the strength and stiffness study, a combination of 70% fly ash and 30% stone dust aggregate with 6% cement can be considered for the base layer. Regarding the behavior of indirect tensile strength and flexural strength, an optimum fiber percentage of 0.35% is recommended.

Fabrication of a sandwich panel by integrating coconut husk with polyurethane foam and optimization using R2

As the need for a sustainable solution increase, waste materials are gaining popularity in building applications to reduce the environmental impact. This study aims to utilize the waste Coconut Husk (CH) and Calcium Silicate Board (CSB) in a sandwich panel where Polyurethane Foam (PU) is used as a binding material which consists of A (isocyanate) and B (polyol) with a mixing ratio of A: B at 1:1.2. CH is obtained as a residue from the production of coconut shells aggregate. The PU has been replaced with CH at 10, 20, 30, 40 and 50 %, to identify the optimum replacement level. Sandwich panels of dimension 30 × 30 cm with a core thickness of 2 and 3 cm was prepared and tested to categorize their mechanical properties, thermal properties, durability properties, characterization study and sound absorption coefficient. The results show that the PU replaced with 20 % of CH has higher compression and flexural properties, owing as an optimum percentage. The inclusion of CH in the PU reduces the cell size and yields a significant improvement in acoustic behavior up to a frequency of 1600 Hz. The regression model was analyzed with the experimental data and validated by the suitable R2 threshold accuracy as R2 > 0.90.

Enhanced sand strength through low-density polyethylene reinforcement

The current study examined the impact of incorporating low-density polyethylene (LDPE) on the behavior of sand through consolidated-drained triaxial tests. The tests varied parameters such as percentage addition and inter-particle void ratio. Results showed that the peak strength of LDPE-mixed sand increased by roughly 40% for 1.5% to 2.0% LDPE content compared to unreinforced specimens. However, peak strength decreased with further increases in LDPE content beyond 2.0%. Thus, LDPE content of 1.5% to 2.0% was identified as the optimal mass percentage for increasing sand strength. The shear stiffness of the LDPE mixed sand also decreased by 25–35% compared to unreinforced samples. The study attributed strength variation and stiffness reduction of sand mixed with LDPE to friction characteristics between sand particle-to-sand particle, sand particles-to-LDPE, and LDPE-to-LDPE, and microscopic observations of the specimens. Although low-friction LDPE reduced initial stiffness, peak strength increased due to the pullout resistance of LDPE sheets across potential shear bands. However, excessive LDPE addition caused pronounced overlapping of LDPE sheets, leading to a decrease in frictional properties and a reduction in strength.

Characteristics and neutron imaging of capillary water absorption for metakaolin and steel fiber reinforced slag based-geopolymer mortars

The manufacturing of cement consumes energy and natural resources of raw materials, and emits large amounts of CO2. Geopolymers are eco-friendly building materials that have the potential to replace cement-based building materials. We used neutron radiography to report new data on water absorption and distribution in metakaolin (MK) and steel fiber reinforced slag-based mortars for the first time. Due to contradictory studies on the influence of adding steel fibers to slag-based geopolymers on compressive strength and the limited research on water permeability, workability and sorptivity, new results were presented. Alkaline-activated MK and steel fiber reinforced slag -based geopolymer mortars were prepared. The neutron radiography (NR) technique was used to investigate capillary water absorption in the mortars. The fresh and mechanical strengths of the mortars, as well as their permeability, workability and sorptivity, were determined. The compressive, flexural, and splitting tensile strengths, as well as the water permeabilities, increased, whereas the workability decreased as the steel fiber percentage in slag-based mortars increased. The results showed that the addition of steel fiber at volume fractions of 1%, 2%, and 3% increased the −7 and 28 days compressive strengths for the slag-based mortars by 44.7%, 50.7%, and 57.1% and 41.9%, 50.2%, and 55.1%, respectively. The NR results revealed that the resistance to water penetration in reinforced slag-based mortars is greater than that of MK. The addition of steel fiber introduced inhomogeneity in the matrix of the reinforced samples and created water-accumulating regions. Water proceeded regularly in the Mk samples but irregularly in the slag-based mortars. The capillary absorption factors k for Mk and slag-based mortars with steel fiber at volume fractions of 1%, 2%, and 3% were found to be 0.37 cm min−1/2, 0.2 cm min−1/2, 0.17 cm.min−−1/2, 0.19 cm min−1/2, and 0.2 cm min−1/2, respectively. According to NR, the optimal percentage of steel fibers in the slag-based mortar impeding water flow is 1%–2%. Steel fiber used at a high proportion to slag-based mortars increased sorptivity. To best fit the results at high absorption times, the second Fick's law of diffusion can be used.

Facile synthesis of N-doped TiO2 nanosheets with exposed (001) facets for enhancing photocatalytic activity

Nitrogen-doped TiO2 with exposed (001) facets was prepared by hydrothermal method using TiN as precursor. The effect of the proportion of HF and HCl on the crystal structure, morphology, optical properties and photocatalytic activity were investigated. The photocatalytic performance of N-doped TiO2 nanosheets was evaluated by the degradation of methylene blue (MB) under xenon lamp light source. The results showed that TiO2 demonstrated nanorod structure with a single rutile phase in the absence of HF while anatase TiO2 exhibited nanosheet structure with exposed (001) facets in the presence of HF. With the increase of HF addition, the degradation rate of the N-doped TiO2 decreased gradually. When the addition of HF was 1 mL, TiO2 showed the highest photocatalytic activity, which was mainly attributed to the large specific surface area and optimal percentage of exposed (001) facets.

Development of soy whey fortified orange juice beverages: their physicochemical, rheological, antioxidant, and sensory properties

Aim: Soy whey is a byproduct of tofu production and is being discarded after tofu preparation. However, soy whey is a rich source of phytochemicals, minerals, and protein. The present study was conducted to utilize soy whey for the development of nutraceutical-rich orange juice beverages. Methods: The soy whey and orange juice were produced and beverage samples were developed from them. The samples were evaluated for physicochemical, rheological, antioxidant, and sensory properties to evaluate the optimum percentage of soy whey that can be utilized for beverage development. Results: The protein content increased from 0.45% to 1.65% with an increase in soy whey from 0% to 50%. The pH of the beverage samples was in the range of 4.27–4.77 with the total soluble solids (TSSs) of 5.75–6.0 for various beverage samples. The lightness (L*), redness (+a*), and yellowness (+b*) of beverage samples range between 31.57–49.04, 1.21–0.54, and 25.37–39.63 respectively. The vitamin C content of the beverage samples was 56.30 mg/L, 52.75 mg/L, 36.97 mg/L, 26.35 mg/L, and 22.87 mg/L for A, B, C, D, and E beverages respectively. The 1, 1-diphenyl-2-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP), reducing power ranges of beverage samples range between 91.2–96.23%, 0.521–0.994%, and 0.204–0.859% respectively, and total phenolic content (TPC) ranges between 112 mg gallic acid equivalents (GAE)/100 mL and 181 mg GAE/100 mL of beverage samples. The beverage samples presented a shear thinning property with a flow index (n) ranging between 0.2371–0.8214. The consistency coefficient of the beverage samples ranges between 0.0405 Pa∙Sn and 0.0041 Pa∙Sn. The control, 20%, and 30% soy whey-containing beverage samples showed higher sensory properties. Conclusions: The beverage samples with 0%, 20%, and 30% showed improved DPPH and FRAP percent activity and higher overall acceptability compared to 40% and 50% soy whey-containing beverage samples.

Fuzzy modeling and characterization of mechanical and biological properties of a selective laser melting shape: A comprehensive study

The bone scaffold is a porous structure that possesses suitable biological and mechanical properties similar to those of natural bone, thereby providing a suitable substrate for bone growth. The scaffold plays a temporary role in the bone repair process and is composed of degradable material that gradually degrades over time to enable new bone growth and replacement. The scaffolds are implanted using bone morphogenetics of transplanted bone-protein (BMP-7) and implanted subcutaneously to assess biological properties and tissue growth. This study demonstrates the ability to design and fabricate a titanium scaffold with a porous architecture using the Selective Laser Melting (SLM) method, employing two different geometries. The scaffolds' mechanical properties are assessed via a compression test, and the results are utilized for finite element analysis (FEA), predicting the designed metallic scaffold's optimal geometric shape and porosity percentage. The biological response of the scaffolds is evaluated via simulated body fluid (SBF) and phosphate buffer saline (PBS) analyses. The findings indicate that the 8-sided scaffold has superior mechanical and biological features compared to the circular and 6-sided geometries. To predict the scaffold's specifications before conducting the experiment, a fuzzy modeling system is used to model the effect of inputs such as weight percentage, elastic modulus, porosity, and Poisson ratio on the compressive strength output variable.

The effects of graphene oxide addition on low velocity impact performance of aramid fiber reinforced epoxy composites

AbstractIn this study, the impact of incorporating graphene oxide (GO) nanoparticles into the matrix of aramid fiber reinforced polymer (AFRP) composites was investigated. The GO nanoparticles were dispersed in the AFRP matrix at three different weight percentages: 0.1%, 0.3%, and 0.5%. The fabrication of the GO dispersed AFRP nanocomposites was achieved using the vacuum assisted resin infusion molding (VARIM) method, and the AFRP plates were cut using a water jet. The sectioned specimens of the fabricated nanocomposites were subjected to low velocity impact tests. The effects of introducing GO nanoparticles at different percentages were evaluated by analyzing the contact force, deflection, maximum absorbed energy versus time and contact force versus deflection curves. Finally, the key parameters of low velocity impact, including contact force, deflection, and maximum absorbed energy, were compared for the different fabricated AFRP nanocomposites. Based on the results, the AFRP composite with 0.3 wt.% of GO nanoparticles exhibited the best performance under low velocity impact loading conditions. However, the agglomeration of nanoparticles became a significant challenge when higher percentages of GO nanoparticles were added to the composite structure. The findings highlight the importance of determining the optimal percentage of nano materials for incorporation into composite structures.

Optimizing energy retrofitting of existing buildings through combinations of advanced noninvasive interventions: a case study in a hot climate zone

Purpose This purpose of this paper is to address the problem of reducing energy consumption in existing buildings using advanced noninvasive interventions (NVIs).Design/methodology/approach The study methodology involves systematically developing and testing 18 different NVIs in six categories (glazing types, window films, external shading devices, automated internal shades, lighting systems and nanopainting) to identify the most effective individual NVIs. The impact of each individual NVI was examined on an exemplary university educational building in a hot climate zone in Egypt using a computational energy simulation tool, and the results were used to develop 39 combination scenarios of dual, triple and quadruple combinations of NVIs.Findings The optimal 10 combination scenarios of NVIs were determined based on achieving the highest percentages of energy reduction. The optimal percentage of energy reduction is 47.1%, and it was obtained from a combination of nanowindow film, nanopainting, LED lighting and horizontal louver external. The study found that appropriate mixture of NVIs is the most key factor in achieving the highest percentages of energy reduction.Practical implications These results have important implications for optimizing energy savings in existing buildings. The results can guide architects, owners and policymakers in selecting the most appropriate interventions in existing buildings to achieve the optimal reduction in energy consumption.Originality/valueThe novelty of this research unfolds in two significant ways: first, through the exploration of the potential effects arising from the integration of advanced NVIs into existing building facades. Second, it lies in the systematic development of a series of scenarios that amalgamate these NVIs, thereby pinpointing the most efficient strategies to optimize energy savings, all without necessitating any disruptive alterations to the existing building structure. These combination scenarios encompass the incorporation of both passive and active NVIs. The potential application of these diverse scenarios to a real-life case study is presented to underscore the substantial impact that these advanced NVIs can have on the energy performance of the building.

Effect of leachate contamination in municipal solid waste on clay liner characteristics

Landfill leachate is generated as a consequence of water percolation through the solid waste, oxidation of the waste, and corrosion of the waste. Under-designed landfill sites allow the leachate to easily pass through the soil strata. To identify the effect of contaminants on the engineering properties of the clay liner, a pilot-scale lysimeter was developed. Experiments on two types of soils polluted with leachate were conducted which included silty clay and soil enhanced by chemical stabilization. Lime and silica fume are used as reactive barriers in landfill earthen liners. The leachate generated was monitored periodically and sampled for (pH, Electrical conductivity, Chemical oxygen demand, Chloride, Total dissolved solids, and total suspended solids). Lime (L), silica fume (SF), and lime-silica fume (L-SF) mix have been used for stabilizing soil. Three percentages were used for lime (2%, 4% and 6%) and three percentages were used for silica fume (3%, 5% and 7%) and the optimum percentage of silica fume (5%) was mixed with the proportions of lime. The optimum lime values are 4% from the research and 5% for silica fume. Soil samples were analyzed over a maturation period of 135 days for each run to identify the chemicals and their effect on the soil characteristics. The plasticity index of the stabilized soil continues to decline until it reaches 36% over the 135 days of the maturing period. Furthermore, an increase in silty clay soil hydraulic conductivity was observed from 3.3 × 10−6 cm/sec to 5 × 10−6 cm/sec at 135 days of maturation. Whereas there is a sharp decrease in hydraulic conductivity to achieve a maximum value in the stabilized soil (1.25 ×10−10 cm/sec). Based on laboratory test results, it can be concluded that soil stabilization can improve the geotechnical properties of landfill earthen liners due to pozzolanic reactions.

Influence of coconut husk on mechanical properties as a filler with polyurethane foam in the sandwich panel—an experimental study

To reduce the environmental impact of construction, use of waste materials has become popular in building applications. In this study, waste coconut husks (CHs) and calcium silicate boards (CSB) are incorporated into a sandwich panel using polyurethane foam (PU) as binding material. PU is made up of A (isocyanate) and B (polyol), which are mixed at a ratio of 1:1.2. To determine the optimum replacement level, PU was replaced with CH at 10, 20, 30, 40 and 50%. A sandwich panel with an outer dimension of 30 × 30 cm and a core thickness of 2 and 3 cm was prepared and tested for its mechanical properties, thermal properties, durability properties and characterization study. The microscopic image showed that the replacement of PU with CH at 50% showed maximum reduction in porous size, but its composite has achieved higher compressive strength at 20%. Hence the optimum percentage of replacing PU with CH is found to be 20%. Further, analytical work was carried out to validate the experimental results through regression analysis and suitable threshold with an accuracy of R2 > 0.90 was obtained.