Communications in Science and Technology

Simultaneous photoelectrocatalytic hydrogen production and ammonia degradation using titania nanotube-based photoanodes

Tiur Elysabeth, Eniya Listiani Dewi, Ratnawati, Kamarza Mulia, Slamet — Tue, 31 Dec 2024 00:00:00 +0000

The primary focus of this research is to enhance the efficiency and effectiveness of the photoanode based of titania nanotubes in the photoelectrocatalytic process, which enables the simultaneous generation of hydrogen and degradation of ammonia. The modification process involved the incorporation of nitrogen dopant during anodization and sensitization of CuO through Successive Ionic Layer Adsorption Reaction (SILAR). The results of this study showed that the introduction of N dopant led to a significant enhancement in both the ammonia elimination and the hydrogen production, as evidenced by 3N-TiNTAs achieving 74.4% and 561 mmol/m², respectively. Meanwhile, the highest hydrogen production was observed with 7CuO-TiNTAs at 910.14 mmol/m². The study revealed that N-TiNTAs exhibited superior performance in ammonia degradation; while CuO-TiNTAs showed higher hydrogen production rates. Furthermore, the mechanistic aspects of the study were also thoroughly examined.

Dual metal NiMo dispersed on silica derived from rice husk ash as a catalyst for hydrocracking of used palm cooking oil into liquid biofuels

Tue, 31 Dec 2024 00:00:00 +0000

The production of vegetable-based fuels has intensified in recent years due to the decreasing availability of fossil fuels and their environmental impacts. This study explores the synthesis, characterization, and application of nickel-molybdenum (NiMo) bimetal-dispersed silica catalysts for converting used palm cooking oil into liquid biofuels. The catalysts were synthesized using the wet impregnation method, incorporating Ni and Mo metals at concentrations of 1, 2, and 3% by weight of silica derived from rice husk ash. Impregnation of the silica with Ni and Mo metals increased its acidity, with the NiMo/SiO? 2 catalyst exhibiting the highest acidity value of 4.34 mmol/g. This catalyst also demonstrated the largest specific surface area and total pore volume, measured at 205.51 m²/g and 0.88 cm³/g, respectively. Hydrocracking of used palm cooking oil into liquid biofuels was performed at an optimum temperature of 450 °C with catalyst-to-feed weight ratios of 1:100, 2:100, and 3:100 for 1 h by hydrogen gas supply of 20 mL/min. Catalyst activity tests revealed the highest mass percentage of liquid product, 23.3%, at a ratio of 1:100 (w/w), with a biofuel yield of 20.34%, comprising 14.20% gasoline and 6.14% diesel. By utilizing biomass waste as both a catalyst and feedstock, this study presents a sustainable approach to reducing the carbon footprint and promoting environmental balance.

Rice husk ash-based selective absorbent with imprinted ionic for gold recovery

Tue, 31 Dec 2024 00:00:00 +0000

The recovery of gold from aqueous solutions is crucial due to its economic value and environmental significance, making effective separation technologies essential. To tackle this challenge, development of an adsorbent with enhanced selectivity and high adsorption capacity against Au(III) is highly crucial. This present study harnessed rice husk derived-silica functionalized by (3-trimethoxysilyl)propyldiethylenetriamine (TMPDT) using imprinted ionic method to form SiO₂-TMPDT-Au-Imp, specifically designed for the selective adsorption of Au(III). SiO₂-TMPDT-Au-Imp demonstrated a significantly higher adsorption capacity about 387% improvement compared to SiO₂-TMPDT, highlighting its superior performance. Furthermore, in addition to exhibit several advantageous characteristics that surpass those of other materials tested, underscoring its effectiveness in Au(III) adsorption. SiO₂-TMPDT-Au-Imp displayed notable selectivity in competitive metal ion solutions with the preference order of Au(III)/Fe(III) < Au(III)/Cu(II) < Au(III)/Zn(II). The developed SiO₂-TMPDT-Au-Imp, in brief, represents a promising advancement in the field of material science and environmental remediation in which it offers a tailored solution for efficient and selective adsorption of Au(III). This study can also be applied for the recovery of Au(III) ions from electronic waste.

Investigation of hexanal removal through adsorption and photocatalysis on ZIF-7 modified with ZnO, TiO\(_2\), and ZnO/TiO\(_2\) using ATR-FTIR

Widyan Muhammad Naufal, Sayekti Wahyuningsih, Witri Wahyu Lestari — Tue, 31 Dec 2024 00:00:00 +0000

Zeolitic imidazolate framework (ZIF) is renowned for its high adsorption capacity and frequently adsorbs organic pollutants. However, its high band gap energy has limited its photocatalytic activity, thus necessitating a modification for enhance performance enhancement. This study focuses on developing a ZIF-7 composite material that integrates adsorption and photocatalysis to remove volatile organic compounds (VOCs), particularly hexanal. Modifications were made by incorporating ZnO, TiO₂, and ZnO/TiO₂ via a solvothermal method using dimethylformamide (DMF). ATR-FTIR analysis was employed to monitor any changes in peak intensity related to the C=O vibrations of hexanal around 1700 cm^-1. The results showed that all samples effectively adsorbed hexanal, reducing peak intensity after UV irradiation, and confirming successful photocatalysis. Notably, TiO₂@ZIF-7 exhibited the highest photocatalytic performance with 88.06% degradation efficiency. This study confirms that the ATR-FTIR method can be used to monitor the success of adsorption and photocatalysis and shows the potential for developing composite materials to remove VOCs such as hexanal.

Modification of Chitosan/PEG4000 dispersed with Lithium Triflate (LiCF\(_3\)SO\(_3\)) as a solid polymer electrolyte for the secondary battery

Tue, 31 Dec 2024 00:00:00 +0000

Secondary battery solid electrolytes attract researchers' attention for being one of the components of the anode and cathode separation in batteries. Currently, battery electrolytes on the market are liquid-based, which have weaknesses in their safety and are not environmentally friendly. Solid-based electrolytes can be a good choice since they excel in the safety and stability of mechanical and electrical properties; however, they still have the disadvantage of low conductivity values (~10^-4 - 10^-6 S/cm), thus requiring modification. The solid electrolytes modification using chitosan can be done by adding other polymers and salts as fillers and Li+ ion-making agents. This scientific paper offers an overview of the development of chitosan-based secondary battery solid electrolytes with the addition of PEG4000 polymer and LiCF₃SO₃. The study was conducted using the solution casting method producing solid electrolytes in the form of membranes. The addition of PEG4000 and LiCF₃SO₃ affected the microstructure and electrical permittivity of the polymer solid electrolyte membrane. PEG4000 as a plasticizer had no significant effect on inter- and intra-molecular bonds due to poor membrane homogeneity; meanwhile, LiCF₃SO₃ could increase the permittivity and ionic conductivity of the chitosan polymer solid electrolyte membrane to 3.199 x 10^-7 S/cm. The chitosan polymer solid electrolyte membrane with the addition of PEG4000 and 30% LiCF₃SO₃ salt has an optimal value compared to other salt concentration variations. The results of this research concluded that LiCF₃SO₃is evenly dispersed in the chitosan/PEG4000 solid polymer electrolyte membrane enabling it to be used as a secondary battery solid electrolyte.

Efficient degradation of methyl orange through photo-Fenton processes with MIL-100(Fe) modified Fe\(_3\)O\(_4\) (Fe\(_3\)O\(_4\)@MIL-100(Fe)) catalyst

Tue, 31 Dec 2024 00:00:00 +0000

The research successfully synthesized a composite MIL-100(Fe) modified Fe₃O₄ (Fe₃O₄@MIL-100(Fe)) catalyst and examined its efficiency in degrading methyl orange (MO) through the photo-Fenton process compared to Fenton. The different percentages of Fe₃O₄ were integrated into MIL-100(Fe) and their effects on material characteristics and degradation capabilities were studied. Ex-situ synthesis involved varying Fe₃O₄ weight ratios (3, 10, and 20% w/w). Characterization techniques confirmed the integration of Fe₃O₄ and MIL-100(Fe) and revealed changes in surface area, pore size, and thermal stability with Fe₃O₄ addition. Meanwhile, removal tests showed promising results with the photo-Fenton process exhibiting maximum efficiency (95.51%) using 10% Fe₃O₄@MIL-100(Fe). This study provides valuable insights into developing efficient photo-Fenton catalysts for environmental remediation, particularly for addressing dye pollution in wastewater by highlighting the potential of Fe₃O₄@MIL-100(Fe) composites in this context.

Decoding brain tumor insights: Evaluating CAM variants with 3D U-Net for segmentation

Dian Nova Kusuma Hardani, Igi Ardiyanto, Hanung Adi Nugroho — Tue, 31 Dec 2024 00:00:00 +0000

Brain tumor segmentation is critical for effective diagnosis and treatment planning. While, conventional manual segmentation techniques are seen inefficient and variable, highlighting the need for automated methods. This study enhances medical image analysis, particularly in brain tumor segmentation by improving the explainability and accuracy of deep learning models, which are essential for clinical trust. Using the 3D U-Net architecture with the BraTS 2020 dataset, the study achieved precise localization and detailed segmentation with the mean recall values of 0.8939 for Whole Tumor (WT), 0.7941 for Enhancing Tumor (ET), and 0.7846 for Tumor Core (TC). The Dice coefficients were 0.9065 for WT, 0.8180 for TC, and 0.7715 for ET. By integrating explainable AI techniques, such as Class Activation Mapping (CAM) and its variants (Grad-CAM, Grad-CAM++, and Score-CAM), the study ensures high segmentation accuracy and transparency. Grad-CAM, in this case, provided the most reliable and detailed visual explanations, significantly enhancing model interpretability for clinical applications. This approach not only enhances the accuracy of brain tumor segmentation but also builds clinical trust by making model decisions more transparent and understandable. Finally, the combination of 3D U-Net and XAI techniques supports more effective diagnosis, treatment planning, and patient care in brain tumor management.

Conductivity and mechanical properties of PEO/PVA/UiO-66 composite polymers for membrane of lithium-ion batteries

Aep Patah, Achmad Rochliadi, Aditya Husein, Dadang Ramadhan — Tue, 31 Dec 2024 00:00:00 +0000

Lithium batteries are crucial for energy storage in electronics, transportation, and industrial sectors. However, lithium-ion battery separators such as Celgard require significant improvements, particularly in ionic conductivity (?). Combining Metal-Organic Frameworks (MOFs) with polymers is expected to create a separator membrane that enhances conductivity and mechanical properties in lithium-ion batteries. UiO-66 MOFs were synthesized using the solvothermal method at 120? and then composited with polyethylene oxide (PEO) and polyvinyl alcohol (PVA) polymer membranes using the solution casting method. The UiO-66 MOFs/PEO/PVA polymer composites were made by varying the UiO-66 content from 2% to 8% (w/w) while keeping a constant LiPF₆ concentration of 9% (w/w). These composites were characterized using X-ray Diffraction (XRD) and Fourier-Transform Infrared spectroscopy (FTIR). Subsequently, the EIS test and tensile tests assessed the performance of the composite membranes. The resulting membrane with 6% (w/w) UiO-66 MOFs exhibited a conductivity (?) of 5.60 × 10^–3 S cm^–1 and a tensile strength of 32.5 MPa.

Understanding the regenerating capacity on photodegradation of methylene blue of titania supported mesoporous silica with the aid of gelatin-P123 as bitemplate

Maria Ulfa, Ika Uswatun Hasanah, Hasliza Bahruji — Wed, 25 Dec 2024 00:00:00 +0000

Mesoporous silica (MS) was successfully synthesized via the sol-gel method using gelatin-P123 as a bi-template under hydrothermal reaction conditions at 100 ºC for 24 h, followed by calcination at 550 ºC for 5 h. The amount of TiO? in MS was adjusted to 1, 5, and 10% (w/w) and characterized using XRD, FTIR, SEM-EDX, N? adsorption-desorption, and UV-Vis. The crystallinity of the samples increased with higher TiO? content, as confirmed by XRD data. SEM analysis revealed that the morphology of MS and TiO?/MS was cylindrical, with a particle size distribution of 0.4–0.6 µm. The surface area of MS was 500.8 m²/g, which decreased to a range of 369.6–454.8 m²/g after TiO? modification, while the pore diameter increased from 28.22 to 34.61 Å. The adsorption efficiency for methylene blue photodegradation reached a maximum value of 95%, demonstrating excellent catalytic performance. Thermal regeneration proved to be a promising strategy to recover the photocatalytic efficiency of TiO?/MS for more than five cycles. Furthermore, thermal regeneration and the reuse of catalysts in wastewater treatment systems provide cost-effective solutions for pollutant removal.

Data-driven modeling approaches for pressure drop prediction in a multi-phase flow system

Nezar M. Alyazidi, Aiman F. Bawazir, Ala S. AL-Dogai — Tue, 31 Dec 2024 00:00:00 +0000

Accurate prediction of pressure drops in multi-phase flow systems is essential for optimizing processes in industries such as oil and gas, where operational efficiency and safety depend on reliable modeling. Traditional models often need help with the complexities of multi-phase flow dynamics, resulting in high relative errors, particularly under varying flow regimes. In this study, we simulate a comprehensive multiphase flow experimental data collected from the lab. This study presents innovative methods for accurately modeling pressure drops in multi-phase flow systems. It also studies the complicated dynamics of multi-phase flows, which are flows with more than one phase at the same time. It does this by using two different data-driven models, nonlinear ARX and Hammerstein-Wiener, instead of neural networks (NNs), so that the models don’t get too good at fitting environments with lots of changes and little data. Our research applies system identification approaches to the intricacies of this domain, providing new insights into choosing the best appropriate modeling strategy for multi phase flow systems, taking into account their distinct properties. The experimental results show that the nonlinear Hammerstein-Wiener and ARX models were much better than other methods, with fitting accuracy rates of 81.12% for the Hammerstein-Wiener model and 86.52% for the ARX model. This study helps the creation of more advanced control algorithms by providing a reliable way to guess when the pressure drops and showing how to choose a model that fits the properties of the multi-phase flow. These findings contribute to enhanced pressure management and optimization strategies, setting a foundation for future studies on real-time flow control and broader industrial applications.

Annealing temperature modify of crystalline structure, magnetic properties and antibacterial performance in nickel substituted cobalt ferrite nanoparticles utilizing natural-fine-sediment

Tue, 31 Dec 2024 00:00:00 +0000

This study details the nickel-substituted cobalt ferrite nanoparticle employing natural fine sediment (NiCFO-fs) annealing temperature dependency of crystalline and magnetic characteristics. The NiCFO-fs nanoparticles were prepared by the coprecipitation method with varying annealing temperatures (200-500°C with increment of 100°C for five hours). As a comparison, Ni-CFO was also synthesized using pure analytical chemicals (NiCFO-pa). The XRD results showed that the whole Ni-CFO nanoparticles established an inverse spinel face center cubic (fcc) order according to space group Fd-3m for both NiCFO-fs and NiCFO-pa. There was no additional peak, indicating that Ni²⁺ cations successfully substituted in cobalt ferrite nanoparticles. In case of NiCFO-fs nanoparticle samples, a crystallite size (D) decreased with the increasing annealing temperature (Ta), namely 45.72 nm, 37.35 nm, 25.95 nm, and 20.51 nm. In contrast to NiCFO-pa, the D increased with the increase of the Ta, i.e., 19.67 nm, 20.74 nm, 21.99 nm, and 23.33 nm. Meanwhile, FTIR results showed the presence of metal-oxygen bonds at 551-586 cm^-1 and 384-391 cm^-1 at tetrahedral (k₁) and the octahedral (k₂) sites for both NiCFO-fs and NiCFO-pa nanoparticles samples. The VSM result showed that a narrow hysteresis curve was observed for the NiCFO-fs sample compared to NiCFO-pa. The NiCFO-fs nanoparticles owing the smallest coercive field (H_C) of 79.5 Oe were attained for the Ta of 300°C. In case of NiCFO-fs samples, magnetization saturation (M_S) decreased with the increase of the Ta in contrast to NiCFO-pa samples. Here, the redistribution of two and three plus ions in the sub-lattice k₁ and k₂ locations should be encouraged by the Jahn-Teller phenomenon through strain-induced magnetism. The findings of the antibacterial test indicated that the potential of NiCFO based on natural materials (fine sediment) was higher than that of NiCFO based on pure analytical chemicals. This result was also supported by the emergence of ZOI magnitudes for all NiCFO-fs materials compared to NiCFO-pa that was only at Ta = 300°C.

Effectiveness extract of Crataeva nurvala leaves as insecticide against Spodoptera litura

Hastini Ma'rufah, L. Hartanto Nugroho, Sukirno Sukirno — Tue, 31 Dec 2024 00:00:00 +0000

Spodoptera litura Fabricius, an insect pest, is known to be highly detrimental to farmers for having a variety of host plants. The application of synthetic insecticides to eradicate pests has been proven to bring many negative impacts, especially regarding the cases of resistance and the presence of residues that are harmful to the environment. This study aims to study the effectiveness of potential bioactive compounds of Tigarun leaves (Crataeva nurvala Buch. Ham) as the biochemical insecticides of S. litura. Tigarun plant, widely used as traditional medicine, contains the potential bioactive compounds for bioinsecticides. The extraction process was carried out by maceration using methanol and ethyl acetate solvents, which were then identified for compound content through GCMS analysis. The bioassay method was performed using the test parameters of mortality and eating power of S. litura instar II larvae. The crude extracts from the two solvents obtained showed their effectiveness as bioinsecticides against S. litura instar II larvae. The highest efficacy occurred in the ethyl acetate extract using the contact poison method with the lowest LC50 value of 0.11. Both extracts were also able to reduce the appetite and provide sublethal effects on S. litura larvae. GCMS analysis indicated the presence of several compounds as insecticides in both Tigarun leaf extracts such as 1,2,3-Propanetriol (CAS) Glycerol; Tetradecanoic acid (CAS) Myristic acid; 9-Hexadecenoic acid; n-Hexadecanoic acid; oleic acid; Heneicosane; and Neophytadiene and several other compounds. This study recommends Tigarun leaf extract (C. nurvala) ethyl acetate with the contact method as a natural insecticide against S. litura.

Discovery of thymol-fused chalcones as new competitive \(\alpha\)-glucosidase inhibitors: Design, synthesis, biological evaluation, and molecular modeling studies

Tue, 31 Dec 2024 00:00:00 +0000

This study aims to synthesize and evaluate the inhibitory activity of thymol derivatives targeting ?-glucosidase using in vitro and in silico studies. Ten thymol derivatives (2-11) including five new thymol-fused chalcones (7-11) were successfully synthesized. Among them, four compounds (4, 8, 9, 11) showed the best inhibitory activity with IC₅₀ values of 18.45, 13.75, 8.86, and 10.67µM compared with acarbose (IC₅₀ = 832.82 µM), respectively. The kinetic study of three new thymol-fused chalcones (8, 9, 11) exhibited a competitive inhibition. Molecular docking demonstrated the predicted interactions between ligand (8, 9, 11) and ?-glucosidase, which are responsible for inhibiting the enzyme's catalytic abilities. Furthermore, molecular dynamics simulation of the enzyme-ligand 9 complex indicated that this complex was stable in aqueous condition. This research contributes significantly to the understanding of thymol-fused chalcones that may have therapeutic potential and their possible application in the treatment of type 2 diabetes mellitus (T2DM) for further study.

Klanceng Honey (Tetragonula laeviceps): Its effect on fasting blood glucose, lipid and hematological profiles, and pancreatic histopathology of diabetic rats

Tue, 31 Dec 2024 00:00:00 +0000

This study aims to assess the daily ingestion of Klanceng Honey (KH) on fasting blood glucose (FBG), high-density lipoprotein (HDL), total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL), and pancreatic histopathology. Thirty rats were involved and divided into six groups: G1 = untreated normal rats, G2 = untreated diabetic rats (DR), G3 = DR treated with 0.9 mg/kg BW glibenclamide, G4, G5, and G6 = DR treated with 1, 2, and 3 g/kg BW KH, respectively for 28 days. The FBG level of G1 was found lower than that of diabetic rat groups (G2–G6) (p<0.01). The TC level of G1 group on 14^th and 28^th days was lower than that of G2–G6 groups (p<0.01). The TG levels in all rat groups showed no significant difference at 0–28 days. On 14^th day, the LDL level of diabetic groups were higher than the one in G1 group (p<0.01). Meanwhile, on 14^th and 28^th, the HDL levels of G3–G6 groups, were higher than the one in G1 group (p<0.01). The pancreatic histopathology of all rat groups showed no abnormalities of the Langerhans islets. The daily ingestion of KH prevented FBG, TC, TG, and LDL levels from rising, increased the HDL levels, and protected the pancreatic glands against damage. T. laeviceps honey can potentially be used as a functional food for therapy of DM patients.

One-pot sol-gel process and simultaneous formation silica particles cross-linked network (SPCN)

Nguyen Nhat Nam — Tue, 31 Dec 2024 00:00:00 +0000

In this work, a simple sol-gel process method was studied for “one-pot” fabrication of silica particle cross-linked networks (SPCN). It is the first time that the co-precursors of tetraethoxysilane (TEOS) and ?-glycidoxypropyltrimethoxysilane (GPTMS) and capping agent of cetyltrimethylammonium bromide (CTAB) are formulated to achieve the complete co-polymerization of the reaction solution. The reaction solution proposed involved TEOS and GPTMS (5:1 w/w) for feasibility preparation of SPCN. The copolymerization temperature was set at 40? for 24h of aging time. The results indicated that, by means of cetyltrimethylammonium bromide as a capping agent, SPCN exhibited a well-defined three-dimensional (3D) porous network. The prepared SPCN was used for the synthesis of silica monolithic columns to show interstices distributed across the whole SPCN as well as monolithic columns. The BET surface area of the SPCN column was obtained at approximately 156 m²/g and an average pore width smaller than 26 nm.

Nitrogen fertilizer use reduction by two endophytic diazotrophic bacteria for soil nutrients and corn yield

Nguyen Van Chuong, Trang Nguyen Ngoc Phuong, Thuan Nguyen Van — Tue, 31 Dec 2024 00:00:00 +0000

Today, the utilization of endophytic diazotrophic bacteria (EDB) purposely to minimize the application of urea fertilizer (UF), and enhance soil fertility, crop quality and corn yield in sustainable agricultural practices is an inevitable trend. The experiment was arranged outside the AGU green house of Agriculture Research Center, An Giang university, Vietnam, which consisted of two factors: (i) two EDB species [Bacillus sp. NTLG2-20 (Bacillus A) and Bacillus arybhattai strain CM44 (Bacillus B)] and (ii) three UF ratios (0.0, 100 and 200 kg N ha^-1) and four replications. Research data presented that the fresh cob yield of Bacillus A was found 4.0% higher than that of Bacillus B and 12.7% than that of non EDB inoculation. Furthermore, the inoculation of Bacillus B had 9.02% higher fresh cob yield compared to non-inoculation. The 50% reduction of UF application combined EDB addition obtained the fresh cob with no significant difference, compared to 100% recommended urea application. The interaction between the effectiveness of EDB inoculation and UF reduction was clearly different in favor of corn grown on sandy loam soils with low nutrient contents. Both Bacillus A and Bacillus B had the abilities of high yield and good nitrogen fixation with the potential to simultaneously improve soil fertility and corn yield. The results of this study demonstrated that two strains of Bacillus A and Bacillus B have the potential to promote the growth and increase the yield of peanuts, and it should be suggested for future biological fertilizer production.

Fixing cobalt metal onto mordenite through spray impregnation and its evaluation as a catalyst in transforming used coconut cooking oil into bio-jet fuel

Tue, 31 Dec 2024 00:00:00 +0000

Given the challenges posed by fossil-based jet fuel, research into bio-jet fuel production has intensified to achieve carbon neutrality. The present work reports a significant breakthrough with the successful conversion of used coconut cooking oil into bio-jet fuel utilizing a cobalt-impregnated mordenite catalyst. Cobalt was introduced to mordenite via the spray impregnation method at a concentration of 2% using a CoCl?·6H?O solution. The resultant catalyst was characterized using FTIR, XRD, NH?-TPD, SAA, FESEM-EDX Mapping, TEM, XPS, and TG/DTA instruments. Hydrotreatment was conducted in a semi-batch reactor at atmospheric pressure, employing H? gas at a flow rate of 20 mL/min and a catalyst-to-feed ratio of 1:200 (w/w) for a duration of 2 h. The addition of cobalt significantly enhanced the efficiency of the hydrotreatment by improving the catalytic performance of mordenite as a support material. The liquid product conversion and total bio-jet fuel yield obtained from the hydrotreatment of used coconut cooking oil using the Co/mordenite catalyst were 60.25% and 51.11%, respectively. The highest selectivity for bio-jet fuel was observed in fraction II (450–550 °C) at 88.90%. This catalyst exhibited sustained performance over three consecutive runs, indicating its potential application in the future biofuel industry. Altogether, this research reveals the possibility of employing used coconut cooking oil as a sustainable and promising feedstock to be converted into bio-jet fuel by hydrodeoxygenation and/or hydrocracking reactions.

One pot two-step borylation/fluorination reaction of dysobinin from Chisocheton macrophyllus and its cytotoxicity against cancer cell

Tue, 31 Dec 2024 00:00:00 +0000

Dysobinin is a naturally occurred limonoid, which is a specific form of triterpenoid, mostly found in certain plants, particularly the Meliaceae family. Overall, it has been found that limonoids have a wide range of biological functions. Typically, the compound comprises anticancer, antimicrobial, and anti-inflammatory properties. Even though dysobinin has shown some effectiveness, its potential in pharmacology, so far, is found limited. This study, therefore, aims to enhance the pharmacological properties of dysobinin through the addition of fluorine. To do this, a one-pot, two-step reaction comprising C-H borylation and selectfluor was used to turn dysobinin into two new compounds: 1,2-dihydro-6?-acetoxyazadirone (5) and 1?-fluorodysobinin (6). After the transformation, various spectroscopic methods, including UV (Ultraviolet), IR (infrared), MS (mass spectra), as well as NMR (1D and 2D) were applied to figure out the structures of the new compounds. Accordingly, of the derived compounds, 1?-fluorodysobinin showed significantly higher cytotoxicity against A549 lung cancer cells when compared to dysobinin.

Enhancing dissolving pulp quality of mixed raw materials through pre-hydrolysis kraft-cooking: A study on Acacia crassicarpa and Terminalia catappa

Tue, 31 Dec 2024 00:00:00 +0000

Acacia crassicarpa wood is widely used in Indonesia as a raw material for dissolving pulp (DP) by the kraft-cooking process. Given that Indonesia has a rich variety and abundance of cellulose-rich wood, it is deemed crucial to research alternative raw materials, such as Terminalia catappa wood. As an alternative source of raw material, Terminalia catappa possesses excellent adaptability to various environmental conditions and is easy to grow everywhere. The current research sought to produce DP using the mixtures of materials from these two plant species as raw materials by pre-hydrolysis, kraft-cooking, and Elementary Chlorine Free (ECF) bleaching. The DP produced had ISO brightness > 88%, alpha-cellulose content > 94%, viscosity > 6.2 cP, and pentosan content of 2.54%. The DP quality traits have met the SNI 938:2017 standards for rayon-grade pulp. Acacia Crassicarpa and Terminalia Catappa are the prospective wood mixture for producing high-quality dissolving pulp via the kraft-cooking process.

Techno-economic analysis of biomass-powered fixed bed dryer with air dehumidification for paddy drying

Mohamad Djaeni, Setia Budi Sasongko, Febiani Dwi Utari, Zulhaq Dahri Siqhny — Tue, 31 Dec 2024 00:00:00 +0000

This study introduces the innovative use of synthetic zeolite adsorbents in biomass-powered fixed bed dryers for enhanced paddy drying. The novel integration significantly improves moisture removal and energy efficiency, addressing limitations of conventional drying methods. Key findings include an effective moisture diffusivity of 2.24 × 10?? m²/s and energy efficiency reaching up to 68%. The economic analysis highlights an Internal Rate of Return (IRR) within 2.04 years, confirming the financial viability of this technology. This advanced drying system demonstrates superior performance and sustainability, offering a promising solution for industrial-scale paddy drying.

Drivers of teleworker productivity: A systematic review of the empirical evidence

Tue, 31 Dec 2024 00:00:00 +0000

This paper aims to identify the factors influencing teleworker productivity by reviewing empirical evidence found in the scientific literature on the topic. A systematic review was conducted to gather and evaluate primary literature sources, complemented by a bibliometric analysis of the volume, distribution, and trends in scientific production over the past 24 years. The effects found are heterogeneous, narrow in scope, and sometimes contradictory. Telework significantly impacts productivity, with its effects varying based on intensity, the nature of the tasks performed, and individual, social, and situational factors. This manuscript provides a comprehensive review of the factors influencing teleworker productivity, analyzing 318 research articles to identify the key determinants of productivity in remote work environments. It systematically categorizes these factors into individual, social, and situational dimensions, offering valuable insights for organizations and individuals adapting to the evolving landscape of telework.

Investigating the antimicrobial activity of silver nanoparticles with varying charges green-synthesized from Tabebuia rosea flower

Tue, 31 Dec 2024 00:00:00 +0000

The integration of nanotechnology and biomedicine has driven a significant interest in silver nanoparticles due to their unique properties. This study presents a novel approach by combining Tabebuia rosea flower extract and chitosan to manipulate the surface charges of synthesized silver nanoparticles. These biosynthesized nanoparticles, presenting negative, neutral, and positive charges, were thoroughly analyzed by means of a number of techniques including Ultraviolet-visible spectroscopy, X-ray diffraction, transmission electron microscopy, and Fourier-transform infrared spectroscopy. By incorporating chitosan, the zeta potential of the green-synthesized nanomaterials was modified, shifting from negative to positive. The resultant silver nanoparticles showed the zeta potentials of –24.8 mV for negatively charged particles, +22.9 mV for positively charged ones, and neutrality at approximately 0.04% chitosan. Meanwhile, the particle sizes for the negative, neutral, and positive nanomaterials were 19.7, 15.8, and 14.2 nm, respectively. The antimicrobial and anticancer activities of these biosynthesized nanoparticles were evaluated against gram-negative bacteria (Pseudomonas aeruginosa, Escherichia coli, and Salmonella enterica), gram-positive bacteria (Bacillus subtilis, Lactobacillus fermentum, and Staphylococcus aureus), and cancer cell lines (A549, Hep-G2, KB, and MCF-7). These results highlight the crucial role of surface stabilizers, particle size, and charge in determining the biomedical potential of nanosilver particles. Notably, the biosynthesized silver nanoparticles exhibited a number of promising antimicrobial and anticancer properties, emphasizing their potential for biomedical applications.

Novel colored biomass-waste from food industry sector derived hierarchical porous carbon nanofiber for robust symmetric supercapacitor

Tue, 31 Dec 2024 00:00:00 +0000

A major challenge in the use of supercapacitor energy storage applications is optimizing 3D-hierarchical porous and 2D nanofiber structures to improve the electrochemical performance of colored biomass-derived activated carbon (AC). Therefore, this study aims to synthesize AC from Dracaena Angustifolia (DA) leaves and dregs using a sustainable method through chemical activation and high-temperature pyrolysis. AC was designed to be adhesive-free to maintain the true mechanical properties of the precursor. Research results showed that the sample of DA-dregs-KOH shows optimal results with a specific surface area (317.66 m² g^-1). The electrochemical performance of hierarchical porous carbon treated with 1 M H₂SO₄ electrolyte in a 2-electrode system had a nanofiber structure with the highest specific capacitance (248 F g^-1) at 1 A g^-1 and energy density (12.96 Wh kg^-1) with a coulomb efficiency 84.1%. Based on these results, DA dreg-KOH based porous AC with hierarchical porous morphology shows significant potential to be used as binder-free electrode materials that can produce high-performance supercapacitors as a new renewable and sustainable energy storage solution.

Hydrogenolysis of furfuryl alcohol to 1,2-pentanediol catalyzed by first row transition metal salts

Tue, 31 Dec 2024 00:00:00 +0000

The growing and relatively large market share of 1,2-pentanediol (1,2-PeD) has attracted attention of researchers to find effective and economically viable catalysts. One type of catalyst that can be used for synthesizing this compound is transition-metal-based catalysts, employed in the hydrogenolysis of furfuryl alcohol (FOL). In this study, the hydrogenolysis of furfuryl alcohol were performed with 2-propanol as the hydrogen source and transition metal salts as the catalysts. The used catalysts include first-row early and late transition metals, i.e., ZrOCl₂·8H₂O, VOSO₄·H₂O, FeSO₄·7H₂O, CuSO₄·5H₂O, NiCl₂, Al(NO₃)₃·H₂O, CoCl₂, FeCl₃·6H₂O, and Zn(NO₃)₂·6H₂O. It was found that ZrOCl₂·8H₂O, VOSO₄·H₂O, and FeCl₃·6H₂O demonstrated superior catalytic activity compared to the other catalysts. Optimal reaction conditions for these three catalysts were achieved at 150 °C for 1 hour, using 2-propanol as the hydrogen source. Under these reaction conditions, the ZrOCl?·8H?O catalyst achieved 95.5% conversion of FOL and 30.3% yield of 1,2-PeD, while the VOSO?·H?O catalyst attained 80.5% conversion of FOL and 36.9% yield of 1,2-PeD. Both results were obtained with a low catalyst concentration of 0.6 mmol%. Meanwhile, the FeCl₃·6H₂O catalyst converted 94.9% of FOL and yielded 30.9% of 1,2-PeD, using a lower catalyst concentration of 0.4 mmol%. Kinetic studies suggested that the reactions likely follow pseudo-first-order kinetics with experimental activation energies (E_a) of 65 kJ/mol, 55 kJ/mol, and 37 kJ/mol for ZrOCl?·8H?O, VOSO?·H?O, and FeCl?·6H?O catalysts, respectively. These findings highlight the potential of transition-metal-based catalysts in achieving high efficiency with low loading, emphasizing their suitability for industrial applications.

Synthesis, characterization and performance of Ni/mesoporous silica - NH\(_2\)/mesoporous silica and Ni-NH\(_2\)/mesoporous silica as bifunctional catalyst in one step conversion of waste palm oil to biodiesel

Anissa Fitria, Wega Trisunaryanti, Triyono, Iman Santoso — Tue, 31 Dec 2024 00:00:00 +0000

Sidoarjo mud is a natural material resulted from an unusual natural phenomenon and is rich in silica contents. So far, no studies have been reported about mesoporous silica from Sidoarjo Mud, which is a supported catalyst for one-step conversion to biodiesel. This study aims to explore synthesis, characterization, and applications to demonstrate the heightened activity and selectivity in the esterification- transesterification of waste palm oil into biodiesel, utilizing a one-step method aligned with the principles of green chemistry using two bifunctional catalysts (Ni/MS - NH2/MS and Ni-NH2/MS). The bifunctional catalysts were prepared by means of hydrothermal, wet impregnation, and grafting methods. The highest biodiesel yield (78.77%) was achieved under the condition of 65 °C, 3 h, methanol to oil ratio 21 : 1, and 3wt% of Ni/MS - NH2/MS as the catalyst. The catalyst was able to yield a conversion level as good as ~72% in the 3^rd cycle after regeneration. The research demonstrates the industrial relevance of the catalyst, offering a sustainable solution for biodiesel production and waste management.