The National Science and Technology Development Agency (NSTDA) is an agency of the government of Thailand which supports research in science and technology and its application in the Thai economy.
Peanut shells, a byproduct of peanut processing, generate much waste annually. In this study, peanut shells were used as a carbon source for synthesizing reduced graphene oxide (rGO-PS) via a modified Hummer's method. A nickel sulfide-reduced graphene oxide (rGO-PS/NiS) composite was hydrothermally synthesized to create a 3D composite network. The rGO-PS/NiS composite was mixed with poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) and coated on FTO glass using a doctor blade and employed as a counter electrode (CE) in a dye-sensitized solar cell (DSSC). The prepared composite was characterized using X-ray powder diffraction (XRD) and Raman spectroscopy to study the chemical composition and surface configuration of CEs. Scanning electron microscopy (SEM) was employed for morphological determination. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and Tafel analyses indicated a decrease in charge transfer resistance and increased catalytic activity in the CE. A DSSC based on an rGO-PS/NiS CE achieved a power conversion efficiency (PCE) of 8.45% for a champion cell, which is higher than that of a conventional platinum-based CE (8.02%). These results demonstrate the potential of metal sulfide composites with biomass-derived rGO-like carbon (natural carbon) for efficient, low-cost DSSCs. They offer a sustainable pathway for converting agricultural waste into high-performance CE materials.
This study investigated a mechanical-press torrefaction-assisted carbonization route for producing Napier grass-derived bio-coke. Napier grass was first torrefied under mechanical pressure at 280–340 °C and 20–70 MPa, followed by carbonization at 1000 °C. The effects of torrefaction temperature and pressure on the properties of the torrefied products and resulting bio-cokes were evaluated. Mechanical-press torrefaction densified the biomass and enabled the formation of consolidated bio-cokes after carbonization. Although the carbonization yield increased on a torrefied-precursor basis, severe pretreatment reduced the overall bio-coke recovery from the original biomass. On a whole-sample dry basis, the carbon contents and HHVs of the pretreated bio-cokes ranged from 69.20 to 72.65 wt% and from 25.97 to 27.30 MJ kg−1, respectively, compared with 70.06 wt% and 26.48 MJ kg−1 for BC-Raw NP. BC-TNP-340-45 exhibited the highest carbon content, HHV, and apparent density of 1.03 g cm−3, whereas the highest compressive strength of 41.7 MPa was obtained for BC-TNP-320-70. Raman analysis showed a slight decrease in the ID/IG ratio from 1.158 for BC-Raw NP to 1.037 for BC-TNP-340-45, indicating a modest change in carbon structure. CO2-TGA-DTG-DSC analysis showed that pretreatment shifted the principal CO2 gasification region toward higher temperatures, with Tmax increasing from 881.34 to 970.26 °C. A preliminary Fe2O3 reduction test provided qualitative evidence of metallic Fe formation. Overall, mechanical-press torrefaction effectively modified and densified Napier grass before carbonization, producing bio-cokes with improved mechanical integrity and higher characteristic CO2 gasification temperatures, while also upgrading fuel characteristics under selected pretreatment conditions.
Iron (Fe) toxicity is one of the most important abiotic stresses limiting growth, development, and grain yield attributes of rice, especially in acid sulphate soils. Silicon (Si), a beneficial element, has been reported to regulate Fe-defense responses and adaptive strategies in several plant species. The objective of this study was to assess the effects of foliar application of Si on the performance of rice, including yield traits, grown under Fe stress. Seeds of two rice genotypes, Azucena (Fe-tolerant) and IR29 (Fe-sensitive), were germinated, 4-week-old seedlings were transferred to the soil substrate, and were grown up to booting stage. Individual rice plant was treated with 0 and 1
This study presents cuttable and leak-proof cellulose-silk fibroin fibers containing discrete phase change material (PCM) cores for use in thermally responsive textiles. For warming applications, fibers loaded with n-hexadecane (C16; melting point of 19.7 °C; melting enthalpy of 48.1 J/g, corresponding to 21 wt
Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae) is a destructive lepidopteran pest commonly managed using microbial biopesticides such as Bacillus thuringiensis (Bt), entomopathogenic fungi, and nucleopolyhedroviruses (NPVs). However, the relatively slow speed of action and variable efficacy of these agents can limit their broader application. Vip3Aa35, a vegetative insecticidal protein secreted by Bt strain M190, exhibits strong toxicity against lepidopteran larvae. This study evaluated the potential of Vip3Aa35 to enhance the efficacy of three microbial control agents, Xentari® (Bt-based), Beauveria bassiana BCC 48145, and Spodoptera exigua nucleopolyhedrovirus (SeNPV), under laboratory and greenhouse conditions. When combined with Xentari®, Vip3Aa35 increased overall insecticidal performance and reduced larval killing time. In combination with B. bassiana at sub-lethal concentrations (62.5–125 ng cm–2), Vip3Aa35 markedly enhanced fungal virulence and accelerated larval mortality. Co-application with SeNPV substantially reduced the LC50 and shortened LT50 values, indicating faster viral infection and killing. Greenhouse experiments further demonstrated that Vip3Aa35, even at low application rates (17.78 µg pot–1), improved plant protection when combined with B. bassiana or SeNPV, resulting in reduced leaf damage and more rapid larval death. Early visual symptoms, including fungal outgrowth and virus-induced larval cadavers, were observed sooner in combined treatments than in single-agent applications. Overall, these findings demonstrate that Vip3Aa35 can enhance the performance of fungal, bacterial, and viral biocontrol agents against S. exigua, supporting its potential use as a synergistic component in integrated pest management strategies.
