Healthcare waste management (HCWM) has become the most concerned issue for hospitals to enhance their environmental performance while reducing the waste disposal costs. The present study aims to ...standardize the evaluation criteria for the stakeholders to ensure sustainable environmental development by safe disposal of infectious healthcare waste (HCW). The present study applied the fuzzy‐Delphi method to scrutinize the criteria identified from the literature and experts' opinions and resulted in 20 subcriteria under the following six main dimensions: experience, relationship, environmental factors, technology and qualification, economic factors, and firm's capabilities. Further, this study proposed a hybrid approach based on analytic hierarchy process (AHP) and decision‐making trial and evaluation laboratory (DEMATEL) under fuzzy environment to analyze the importance and interrelationships of these listed criteria. The study also showed that the experts have given approximately 70% weightage to three main criteria: firms' capabilities, economic factors, and technology and qualification. The implications of the study would help the healthcare administration and Pollution Control Boards to prepare check sheets for recording HCWM practices and, hence, contribute to sustainable environmental development in an efficient way. Understanding the prioritized cause‐group criteria would further protect hospitals' environment from the spread of infection caused by the HCW in the long run.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
In this work, decomposable and combustible flexible organic transistors with a cellulose-based dielectric and substrate were demonstrated in an effort to produce biodegradable systems for ...eco-sustainable electronics. High-k cyanoethyl cellulose (CEC) was explored as a suitable gate dielectric candidate for enhancing the biodegradability of flexible devices fabricated on a paper substrate. The fabricated flexible biodegradable transistors exhibited high performance for −5 V operation with excellent saturation in the output characteristics along with remarkable environmental, operational, electromechanical, and thermal stability. Upon thermal annealing, the performance of the devices did not degrade till the temperature of 60 °C, indicating their suitability for practical operating environments. Moreover, the devices exhibited decent stability upon exposure to very high humidity. Most importantly, these devices were decomposed in water-rich soil in 19 days due to the microorganisms present in soil, confirming the excellent biodegradability, which is highly essential for eco-sustainable electronics. Moreover, the combustion of the devices in fire, one of the quickest methods for degradation, led to a significant reduction in mass of more than 75%, leaving ashes primarily consisting of the remains of Ag bottom-gate and Au source/drain electrodes. Our results on the demonstration of flexible devices with full decomposability in soil and high combustibility can be a significant step toward the preparation of fully biodegradable flexible electronics to minimize the effects of e-waste on environment and soil.
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IJS, KILJ, NUK, PNG, UL, UM
•We study the hub location problem faced by an airline entering a competitive market.•The problem is modeled as a non-linear integer program.•We propose four different approaches to solve it.•Our ...best performing method uses Kelley’s cutting plane within Lagrangian relaxation.•It is able to solve all the problem instances within 1% optimality gap in less than 10 minutes of CPU time.
In this paper, we study the hub location problem of an entrant airline that tries to maximize its share in a market with already existing competing players. The problem is modeled as a non-linear integer program, which is intractable for off-the-shelf commercial solvers, like CPLEX and Gurobi, etc. Hence, we propose four alternate approaches to solve the problem. The first among them uses the Kelley’s cutting plane method, the second is based on a mixed integer second order conic program reformulation, the third uses the Kelley’s cutting plane method within Lagrangian relaxation, while the fourth uses second order conic program within Lagrangian relaxation. On the basis of extensive numerical tests on well-known datasets (CAB and AP), we conclude that the Kelley’s cutting plane within Lagrangian relaxation is computationally the best. It is able to solve all the problem instances of upto 50 nodes within 1% optimality gap in less than 10 minutes of CPU time.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•The effect of heat treatment on the dynamic strength of two different rocks (soft and hard rocks) is experimentally studied.•Change in mass and density in rocks due to heating corroborates the ...alteration in dynamics strength in rock.•The progressive fracture in heat-treated rock specimens during dynamic loading is captured using a high-speed camera.•Effect of thermal stress on the rock microstructure is examined using scanning electron microscopy (SEM).
The present study assesses the effects of thermal exposure on the strength, stiffness, and fracture propagation in different rocks subjected to impact loading. The dynamic loading response of soft (synthetic die stone) and medium hard (natural marble) rocks are compared in this study. In the experiments, Split Hopkinson Pressure Bar (SHPB) tests are carried out on the heat-treated rock samples. A high-speed camera records the whole failure process of these specimens, and digital image correlation (DIC) is employed to track the evolution of strain during SHPB compression testing. The variation of mechanical properties of intact rocks with heating temperature is characterized by various thermal zones depending on the transition temperature, which identifies a significant shift in the impact loading response due to heating-induced micro-crack formation. Rocks made of synthetic materials and marble have transition temperatures between 100 and 150 °C and 500 – 650 °C, respectively. In the pre-transition regime, the dynamic compressive strength slightly rises or stays almost unchanged, whereas in the transitional regime, compressive strength falls drastically, and it does not show any vital changes with increasing treatment temperatures in the post-transitional regime. For synthetic rocks and marble, the critical heating durations are 10 and 5 h, respectively, and strength changes are relatively minimal after these heating durations. With increasing temperature (from 30 °C to 300 °C), the fracture pattern of synthetic specimens shifts from shear-tensile-dominated to tensile-dominated followed by shear-dominated. For marble specimens, the fracture pattern shifts from shear-tensile-dominated to shear-dominated as the temperature rises from room temperature to 650 °C.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Low carbon steels could be simply welded by conventional fusion welding processes. However, fusion joining of these steels results to the problems related to melting of metal and solidification of ...weld pool. In the present study, friction stir welding (FSW) of low carbon steel plates was undertaken using tungsten alloy tool to determine the effects of welding parameters on joint quality. Welded joints were characterized by microstructural and mechanical properties. Onion rings, banded structure and swirl zone were observed as a result of process temperature, strain rate, plastic deformation, and material transportation. The results indicate that the grain size of the weld zone is different from the base metal (BM) and slightly lesser to the base metal in the middle region of stir zone. Comparing the advancing side (AS) and retreating side, grain size was similar in the heat affected zone and different in the thermo-mechanically affected zone. The microstructure provides the suitable relationship for the properties and micro hardness of the welded region. Tungsten carbides rich areas were found in the stir zone performed at high heat input weld condition. Interestingly, there is noticeable change in grain size and grain distribution of the tungsten tool after welding.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Fibrous polymer composites are integral materials utilized in various sectors due to their unparalleled material properties. However, their widespread application has led to significant volumes of ...end-of-life material, necessitating sustainable disposal strategies. Conventional disposal methods, landfilling, and incineration exhibit shortcomings in both fiber recovery efficiency and environmental impact. Conversely, recycling presents a viable avenue for fiber recovery, facilitating its reuse in composite fabrication alongside allied industries like construction. This article provides a comprehensive examination of mechanical, thermal, and chemical recycling methods tailored for fibrous composites made of thermoset resins. In addition to traditional approaches, hybrid techniques emerge as compelling recycling prospects, amalgamating various traditional methods to enhance overall process efficiency while mitigating the limitations. This article stands out for its in-depth exploration of the intricate methodologies underpinning hybrid recycling methods. The article also delineates the range of products produced from recycling, encompassing fibers, liquids, and gaseous byproducts. In addition, a dedicated section outlines the potential applications of recovered fibers within the composite industry and their integration into cutting-edge additive manufacturing processes. Through a holistic examination of recycling strategies and their downstream implications, this article underscores the imperative for sustainable practices in the utilization and management of fibrous polymer composites.
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NUK, OILJ, SAZU, UKNU, UL, UM, UPUK
Rocks containing flaws around rock structures are often subjected to complex temperatures and geological conditions. This study investigates the mechanical behavior of heat-treated rock samples with ...a flaw under ungrouted and grouted conditions subjected to dynamic loading. Rock samples were prepared from two different types of rocks, model rock and natural marble, with an existing flaw at a fixed orientation under three different infill conditions, i.e., ungrouted, cement grouted, and epoxy grouted. Samples were initially heat treated to a temperature between 30 and 650 °C for 0–15 h and then subjected to dynamic loading using Split Hopkinson Pressure Bar (SHPB). A high-speed camera was coupled with SHPB to record the progressive failure process of these samples, and Digital Image Correlation (DIC) captured the strain evolution. It was observed that the strength and stiffness of samples remained constant up to a certain temperature, namely transition temperature (i.e., 100–150 °C and 500–650 °C for model rock and marble, respectively) and then reduced significantly. The presence of grouts improved the mechanical behavior of samples significantly. However, their efficiency was dependent on the degree and duration of heating. Epoxy grout was observed to have superior efficiency compared to cement grout at lower degrees and lesser durations of heating which reverses for their higher magnitudes. Except for the epoxy-grouted samples at low temperatures, fracture initiation took place from the flaw tips in all other samples. Fracturing was dominated by tensile cracks at lower degrees and lesser duration of heating which changes to shear cracks-dominated mechanism, especially for porous model rock with the increasing degree and duration of heating.
Highlights
Grouts were efficient in improving the dynamic response of jointed rocks with efficiency dependent upon the heat treatment of samples.
Crack initiation and progression for grouted samples depend on grout strength, degree and duration of heating.
Crack initiation and progression for ungrouted samples depend on the degree and duration of heating.
Epoxy grout was more efficient for lower degree and duration of heating while cement grout was for higher ones.
The transition from tensile-dominated fracturing to shear-dominated fracturing with increasing duration and degree of heating with more dominant effect on porous model rocks as compared to crystalline marble.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Computational time and hardware resource are key issues in hardware implementation of any signal-processing algorithm. This paper presents the design and implementation of a ...polyphase-decomposition-based new architecture of wavelet filter for power system harmonics estimation using discrete wavelet packet transform (DWPT). Usually, DWPT provides coefficients as the output; however, the proposed architecture also includes provision for providing root mean square values directly. The proposed method reduces computational requirements and save memory resources. Xilinx system generator, a higher abstraction level tool, has been used to simulate and implement the proposed scheme on the Xilinx Artix-7 field-programming gate array AC701 board. Performance of the proposed architecture has been validated and compared through hardware cosimulation with variety of synthetic and experimental signals.
Transition in the rate-dependent mechanical response of rock was investigated due to the presence of impersistent joint with different infill conditions. Four types of samples, i.e. intact, jointed ...with no grouting, jointed and grouted with cement, and jointed and grouted with epoxy, were fabricated using model material. A series of dynamic split Hopkinson pressure bar (SHPB) tests was conducted on prepared samples with strain rates varying between 53–130 s−1 along with static uniaxial compression tests (10−4 s−1). Progression of fracture/failure along samples was monitored using high-speed imaging and digital image correlation (DIC). Strength was observed to be significantly lower for jointed samples as compared to intact samples. However, the increasing trend of strength with strain rates remained similar for all types of samples. Epoxy was observed to be a better grout due to greater improvement in the strength of epoxy grouted jointed samples than cement grouted samples under both static and dynamic conditions. Significant changes were observed in fracture behavior (initiation, pattern and mechanism) with strain rate for intact and jointed unfilled/grouted samples. Fracturing was dominated by shear and tensile cracks at high strain rates compared to tensile cracks at low strain rates in all samples. Unlike static loading conditions, the location of cracks initiation shifts away from joint tips with increasing strain rate and depending upon existing infill conditions (unfilled/grouted).
•The effect of an impersistent joint on the rate-dependent strength and fracturing behaviour of jointed rocks is investigated and compared with that of intact rocks.•The effect of joint grouting on the rate-dependent behaviour of jointed rocks is investigated and compared with that of jointed rocks with clean joints.•The efficiency of different grout materials in the improvement of the dynamic response of jointed rocks is investigated.•Suggestive guidelines are provided for the selection of grout materials for jointed rocks under static and dynamic conditions.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Abstract In this paper, a compact low-profile dual-band wearable textile antenna is proposed for on-body and off-body communications. The presented antenna works efficiently in the 5G n79 frequency ...band (4.4 − 5 GHz) and the ISM band (5.725 − 5.875 GHz). The designed antenna has an ultra-wide impedance bandwidth of 2.01 GHz and peak realized gains of 10.5 dBi and 12 dBi at 4.5 GHz and 5.8 GHz, respectively. The antenna has a small footprint (π × 0.3 λ 0 2 ), which is inspired by circular fractal geometry. The performance of the presented wearable antenna is evaluated at various body parts, including the arm, wrist, and chest. The link margin is evaluated in the on-body and off-body communication scenarios, i.e., communication with the implantable antenna and the outside-body antenna, which is 80 dB and 65 dB at 4.5 GHz and 5.8 GHz, respectively. The 1 gm/10 gm specific absorption rate values at 4.5 GHz and 5.8 GHz are 0.12/0.098 and 0.11/0.082, respectively, which are significantly lower than the standard values, making the proposed antenna suitable for modern wearable applications.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
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