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Replacing synthetic fibres with natural fibres as reinforcement fillers in natural rubber (NR) tends to yield eco-friendly bio-composites. This study investigated the tensile and hardness properties, and the thermal behaviour of pineapple leaf fibre (PALF)-reinforced NR composites with and without the addition of multi-walled carbon nanotubes (MWCNT). The fibre content was varied at 0, 10, 20, and 30 parts per hundred rubber (phr) and the MWCNT content was fixed at 10 phr. The surface morphology of the tensile-fractured specimens was examined using scanning electron microscopy (SEM) to identify the rubber-matrix adhesion and tear mechanisms of the fibres in the NR matrix. The results revealed that including the PALF and MWCNT allowed the NR composites to exhibit excellent stretching stress at low elongations. Additionally, the composites displayed enhanced stiffness, further increasing the hardness of the composite, ranging from 46.8 to 62.8 Shore A. However, PALF reduces the thermal stability of the composite, where the initial degradation temperature increases. From the thermogravimetric analysis, the residues remaining in the NR composites ranged from 6 to 13% at various fibre loadings. Therefore, this study provides valuable insights into the tensile and hardness properties and the thermal behaviour of PALF-reinforced NR composites to improve end-use properties.

This study explores the impact of nanofillers on the wear and frictional characteristics of Cellulosic fibre-reinforced composites. With increasing demand for lightweight and durable materials in various industries, understanding the effects of nanofillers on composite performance is crucial. In this research, pin-on-disc trials were conducted under applied loads ranging from 80 N to 140 N, maintaining a constant 50% fibre volume fraction, a sliding distance of 3000 m, and a velocity of 1 m/s. The incorporation of 5 phr graphite powder was systematically investigated, compared to a graphite-absent control group, to elucidate the nanofiller's influence. Experimental results revealed a notable decrease in the Coefficient of Friction (COF) by 2.63 % to 9.09 % across different applied loads. Moreover, the Specific Wear Rate (SWR) exhibited a significant reduction at all loads, with the most substantial decrease of 61.45 % observed at 80 N. SEM analysis provided further insights, indicating a shift in wear mechanisms towards less damaging interactions. These findings highlight the potential of these composites for high-stress tribological applications in industries.

The electromagnetic interference shielding effectiveness (EMISE) and thermal conductivity (TC) of a graphene bio‐based epoxy composite were investigated in this study. This study aims to evaluate the effects of dispersion methods on the EMISE and TC of graphene bio‐based epoxy composites. Four dispersion methods were applied to disperse graphene: hand mixing, high‐shear mixing, ultrasonication, and ultrasonication with high‐shear mixing. The graphene weightage used in this study are 3, 6, and 9 wt.%. The EMISE was examined at the X‐band frequency. A microstructural analysis was performed using scanning electron microscopy to investigate the fracture surface morphology of the composites. The results revealed that the composite with 9 wt.% graphene exhibited the highest shielding effectiveness and TC, averaging 8.35 dB and 0.3855 W/mK, respectively, for all the dispersion methods. The composite with 3 wt.% graphene dispersed via ultrasonication exhibited the highest absorption loss (2.98 dB). Moreover, the composites with 6 and 9 wt.% graphene dispersed via ultrasonication with high‐shear mixing showed good overall improvement. This finding provides valuable insights into the effect of dispersion techniques on graphene bio‐based epoxy composites and presents a suitable dispersion method for improving the EMISE and TC. Highlights: Effect of dispersion methods on EMISE and TC has been investigated.Optimum SEA achieved in 3 wt.% composites dispersed via ultrasonication.Higher wt.% increased the SE and TC of composites.Ultrasonication with high‐shear mixing improved overall results. [ABSTRACT FROM AUTHOR]

Excessive use of tetracycline (TC) is alarming owing to its increased detection in water systems. In this study, a photocatalyst was developed to degrade TC using a Ce-N-co-doped AC/TiO2 photocatalyst, denoted as Ce/N-AC/TiO2, prepared using the sol–gel method assisted by microwave radiation, speeding up the synthesis process. Ce/N-AC/TiO2 achieved maximum TC degradation of 93.1% under UV light with optimum sorption system conditions of an initial concentration of 10 mg L−1, pH 7, and 30 ℃, under 120 min. Scavenger experiments revealed that holes and superoxide radicals were the active species influencing the photodegradation process. The TC degradation was appropriately fitted with Langmuir isotherms and a pseudo-second-order (PSO) kinetic model. The change in enthalpy (ΔH) (2.43 kJ mol−1), entropy (ΔS) (0.024 kJ mol−1), and Gibbs free energy (ΔG) (− 4.941 to − 5.802 kJ mol−1) suggested that the adsorption process was spontaneous, favourable, and endothermic. Electrostatic interaction, hydrogen bonding, pore-filling, cationic-π, n-π, and π-π interaction were among the interactions involved between TC and Ce/N-AC/TiO2. Furthermore, Ce/N-AC/TiO2 stability was confirmed through 80% removal efficiency even after the fifth reuse cycle. Notably, this work provides new insight into the production of efficient, reusable, and enhanced photocatalysts using a rapid and cost-effective microwave-assisted synthesis process for pollutant remediation. [ABSTRACT FROM AUTHOR]

Air velocity is among the most important factors influencing thermal comfort in naturally ventilated spaces in hot and humid tropical climates. It is important to have air velocity that suits comfort needs and enhances the student's learning performance in the classroom, especially in schools that rely only on natural ventilation assisted by ceiling fans. In this study, the thermal comfort and learning performance of students in a selected naturally ventilated classroom at a secondary school in Segamat, Johor, Malaysia, were experimentally evaluated under different air velocity conditions during the peak temperature period during the school session. Throughout the experiment, physical measurement and a subjective evaluation questionnaire were conducted for thermal comfort analysis and to gather the student’s thermal environment evaluation in the classroom. Students’ learning performance was assessed through simple reaction and digit span tests based on the WHO Neurobehavioral Core Test Battery (NCTB). All the assessment results were statistically analyzed, and the relationships among indoor air velocity, thermal comfort, and learning performance were obtained. The result showed optimal learning performance was significant when students felt “slightly cool” and air velocity was more than 0.95 m/s. Hotter environments and a lack of air movement were found to be causes of declining student performance. In conclusion, it is suggested that the comfort zone in a naturally ventilated classroom for school students should be set within the range of -1 (slightly cool) with an air velocity greater than 0.76 m/s.

This article presents the results of the observations about digital literacy that were studied philosophically through Gadamer's hermeneutic approach. The reason for using this approach is to achieve an understanding of how the subject and its history play a role in the digital literacy process, where ontologically, the content of information has been visualized into the digital world so that a philosophical understanding is needed in understanding the virtual reality. This research is included in the classification of qualitative research with an analysis with three stages, namely reducing data that is very general and broad in a more specific form, and relevant to digital literacy and hermeneutics; then classifies the dimensions of digital literacy so that it is easy to determine the dimensions of the hermeneutics; interpret digital literacy to clarify the dimensions of hermeneutics in it, and concludes and draws relevance to efforts to overcome hoaxes. The results obtained from this study are on a hermeneutical analysis of the process of digital literacy as a catalyst for peace, that equalizing the elimination of discrimination at the historical-ego level can be achieved through the application of hermeneutical digital literacy that is by promoting dialectical historical understanding, where contemporary history dialecticism with the history of the past which is often claimed by certain groups as the heyday and the fruit of their work. Artikel ini mempresentasikan tentang hasil observasi peneliti tentang literasi digital yang dikaji secara filosofis melalui pendekatan hermeneutika Gadamer. Adapun alasan penggunaan pendekatan tersebut yakni untuk mencapai sebuah pemahaman tentang bagaimana subjek dan kesejarahannya berperan di dalam proses literasi digital, di mana secara ontologis, konten informasi telah divisualisasikan ke dalam dunia digital sehingga dibutuhkan pemahaman yang filosofis di dalam memahami realitas virtual tersebut. Penelitian ini masuk ke dalam klasifikasi penelitian kualitatif dengan analisis dengan tiga tahap yaitu mereduksi data yang bersifat sangat umum dan luas ke dalam bentuk yang lebih spesifik, dan relevan dengan literasi digital dan hermeneutika; selanjutnya mengklasifikasikan dimensi literasi digital sehingga mudah untuk ditentukan dimensi hermeneutikanya; menginterpretasikan literasi digital dalam rangka memperjelas dimensi hermeneutika di dalamnya; serta menyimpulkan dan menarik relevansinya dengan upaya menanggulangi hoax. Hasil yang didapatkan dari penelitian ini adalah pada sebuah analisis hermeneutis tentang proses literasi digital sebagai katalis perdamaian, bahwa penyetaraan penghapusan diskriminasi pada tataran ego-historis dapat dicapai melalui penerapan literasi digital yang bersifat hermeneutis yakni dengan mengedepankan pemahaman kesejarahan yang dialektis, di mana sejarah masa kini didialektikakan dengan sejarah masa lampau yang seringkali diklaim oleh kelompok-kelompok tertentu sebagai masa kejayaan dan buah kerja mereka.

Artikel ini mengkaji identitas umat beragam sebagai suatu konsep umum dalam diskursus sosiologi agama. Pengkajian tersebut dilakukan dengan menggunakan pendekatan teori strukturasi Anthony Giddens. Adapun elemen utama dalam teori tersebut adalah struktur penandaan (signifikasi), struktur dominasi, dan struktur legitimasi. Ketiga elemen tersebut digunakan untuk memahami proses konstruksi identitas umat beragama, mulai dari pelibatan wacana, istilah, dan konfigurasi bahasa sebagai langkah mengartikulasikan pemahaman tentang realitas sosial. Pemahaman itu kemudian merigidkan simbol-simbol keagamaan yang menjadi penanda identitas kolektif. Tahapan berikutnya yaitu tahap pembakuan identitas kolektif sebagai identitas umat beragama yang dilegitimasi oleh kuasa-kuasa yang melekat pada pelaku (agency) sehingga menjadikan identitas umat beragama menjadi baku. Ketiga struktur itu saling terhubung dalam dualitas yang meneguhkan bahwa struktur bersifat mengakomodir (enabling) bukan pengekangan (constraining), di mana menjadikan tindakan sosial menjadi mungkin. This article examines the identity of various people as a general concept in the discourse of the sociology of religion. The assessment was carried out using the Anthony Giddens structuration approach. The main elements in this theory are the structure of signification, the structure of domination, and the structure of legitimacy. These three elements are used to understand the process of constructing the identity of religious communities, starting from the involvement of discourse, terms, and language as a step to articulate an understanding of social reality. That understanding then trifles the religious symbols that become collective identities. The next stage is the stage of standardizing collective identity as the identity of religious communities which is legitimized by the power attached to the actor (agency) so that the identity of the religious community becomes standardized. The three structures are interconnected in a duality that affirms that the structure is accommodating (enabling) not constraining, where social action becomes possible.

In this study, a statistical optimization design experiment was conducted using a face-centered central composite design-response surface methodology for the preparation of AC/TiO2-Cu ternary composite photocatalysts. The influence of preparation variables such as AC/TiO2 ratio (A = 0.1–0.5), Cu dosage (B = 0.1–0.5 g), irradiation power (C = 400–800 Watts), and irradiation time (D = 10–20 minutes) on the removal efficiency of Metronidazole (MZ) was investigated. From ANOVA analysis, the findings show 89.0% removal of MZ at the optimum preparation variables of A = 0.49, B = 0.34 g, C = 482 W, and D = 13 minutes. The regression analysis with an R2 value of 0.9907 indicates good agreement between the experimental results and the predictive values. Further studies on isotherms and kinetics were well described by the Langmuir model and pseudo second-order model, respectively. The synergetic mechanisms for the adsorption–photodegradation included three possible interactions (electrostatic attractions, π–π stacking interaction, and n–π stacking interactions) and the photogenerated electron-hole pair. From the radicals quenching test, hydroxyl radical (•OH) was found to be the most active radical for the removal of MZ. AC/TiO2-Cu ternary composite photocatalyst could be preserved up to five consecutive cycles with minor losses in removal (<9%). The results of this study show that the prepared AC/TiO2-Cu ternary composite photocatalyst substantially enhanced the adsorption–photodegradation of MZ removal in an aqueous solution under UV light irradiation. [ABSTRACT FROM AUTHOR]

Nitrogen (N) and cerium (Ce) co-doped titanium dioxide (TiO2) supported activated carbon (AC) (N-Ce-AC/TiO2) were synthesized to remove antibiotic tetracycline from aqueous solution via adsorption and photodegradation. The sol--gel technique, aided by microwave radiation, was used to synthesize N-Ce-AC/TiO2. Central composite design under response surface methodology was used to optimize the variables comprising urea (N source) (A: 0.02-0.20 g), cerium(III) nitrate hexahydrate (Ce source) (B: 0.02-0.20 g), activated carbon (C: 0.10-0.50 g), and microwave power (D: 600--800 W), where the degradation of tetracycline was the response. Characterization of the produced catalyst was carried out by means of X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and the Brunauer--Emmett--Teller method for determining surface-texture parameters. N-Ce-AC/TiO2 prepared with 0.50 g activated carbon, doped with 0.02 g urea and 0.20 g cerium, and activated at microwave power 600 W for 15 min exhibited 91.08% tetracycline removal when subjected to 7 W of UV irradiation, according to the results of optimal variable preparation. [ABSTRACT FROM AUTHOR]

The increasing environmental pollution caused by the disposal of untreated dye-containing effluent and face mask wastes in landfills has become a significant concern. To address this issue, this work focuses on the utilization of face mask wastes as alternative adsorbents for the adsorption of malachite green (MG) dye. These adsorbents offer advantages such as ease of operation, cost-effectiveness, high efficiency, and ready availability. In this study, the raw face mask wastes (RFM) undergo a thermal treatment process in a furnace at 800°C for 21 h before conducting the adsorption tests. The Fourier-transform infrared spectroscopy analysis revealed the presence of various functional groups, including alkane, alkene, alcohol, and carbonyl, in both the treated face mask adsorbent (TFMA) and RFM. The scanning electron microscopy with energy-dispersive X-ray spectroscopy analysis displayed the surface morphologies of RFM as a porous and homogeneous carbon sorbent structure, while TFMA exhibited a heterogeneous and flaky structure. Energy-dispersive X-ray spectroscopy analysis indicated that RFM primarily consisted of carbon elements, followed by oxygen and calcium elements, whereas TFMA predominantly comprised calcium and oxygen elements with a limited amount of carbon. The adsorption experiments, considering various parameters such as initial dye concentration (1,000-1,200 mg/L) and contact time (5-1,500 min), demonstrated that increasing the contact time and initial concentration led to an enhanced adsorption capacity. The maximum adsorption capacity of 2,127 mg/g confirmed the effectiveness of TFMA as an adsorbent for MG. Thermodynamic analysis revealed that the adsorption process was spontaneous and endothermic. The isotherm and kinetic studies showed a good fit between the adsorption data and the Brunauer-Emmett-Teller and pseudo-second-order models as evidenced by high R2 values and low error function values, suggesting a heterogenous adsorption of MG on TFMA. [ABSTRACT FROM AUTHOR]

This study presents the preparation of oil palm empty fruit bunch (OPEFB) activated char from gasification plant residues via phosphoric acid chemical treatment for adsorption of methylene blue (MB) in aqueous solution. The Fourier-transform infrared (FTIR), scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) analysis were conducted to identify the characteristic of OPEFB. Adsorption experiments were carried out to determine the effects of initial dye concentration 100-300 mg/L, contact time, pH 2-10 and temperature 30°C-60°C. The optimum conditions were achieved at adsorbent dosage, pH, initial dye concentration and temperature of 0.2 g/200 mL, 6, 100 mg/L and 60°C, respectively with 91.44% of MB removal. From isotherm study, the Freundlich isotherm model fitted the adsorption data very well owing to its higher value of correlation factor (R2 = 0.9352), compared to Langmuir model (R2 = 0.8682). The Langmuir maximum monolayer capacity, qm was estimated at 167.2 mg/g. The results from the kinetic study showed that the MB adsorption followed a pseudo-second-order kinetic model (R2 = 0.9216-0.9581). The adsorption of the MB dye onto OPEFB activated char was an endothermic and spontaneous process with H°, G° and S° values of 58.379 kJ/mol, -0.70505 kJ/mol and 194.955 J/molK, respectively. The obtained results suggest that the OPEFB char could be a promising candidate as an adsorbent for MB removal. [ABSTRACT FROM AUTHOR]

In this work, melunak and rubberwood-based activated carbon (MAC and RAC) were prepared via microwave induced KOH activation for Remazol Brilliant Violet 5R (RBV5R) dye removal from aqueous solution. Batch adsorption experiments were carried out to evaluate the influence of pH, initial dye concentration, and contact time. The textural characterization shows high BET surface area of 914.0 and 796.0 m2/g for MAC and RAC, respectively, which indicate that they are comprised of a micro-mesoporous structure. Langmuir isotherms provided the best model for MAC and RAC adsorption data. The adsorption capacities of RBV5R onto MAC and RAC estimated by the Langmuir model were 238.33 and 204.08 mg/g, respectively. The pseudo-first-order, pseudo-second-order, and Elovich model equations were used to analyse the kinetic data of the adsorption process, and both data fitted well with the pseudo-second-order kinetic model. Film diffusion was the rate-limiting step controlling adsorption based on intraparticle diffusion and the Boyd plot. The adsorption mechanisms involved are pore filling, hydrogen bonding, n-p interactions, and p-p interactions. The thermodynamic parameters confirmed that the adsorption was spontaneous, feasible, and endothermic. Furthermore, a mechanism including physisorption and chemisorption of RBV5R on MAC and RAC has been proposed. The desorption study predicts excellent regenerative efficacy of both MAC and RAC for up to four cycles. [ABSTRACT FROM AUTHOR]

Background: The development of systemic disease after curative surgery for colorectal cancer approaches 30%. This may represent understaging. Sentinel lymph node mapping (SLNM) identifies lymph nodes at high risk of [...]