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Silver nanoparticles are known to play a crucial role in various fields, prompting researchers to undertake synthesis and modification to obtain nanoscale particles. Silver nanoparticles were synthesized using a green synthesis-based chemical method with an extract from Cordyline fruticosa (L.) A. Chev. This study aims to determine the optimum conditions, including pH parameters, reaction time, and concentration, and assess the silver nanoparticles’ stability and characteristics. The research findings revealed that the optimal conditions for synthesizing silver nanoparticles were an extract pH of 11, a reaction time of 60 minutes, a AgNO3 concentration of 1.5 x 10-4 M, and an extract concentration of 0.008%. Characterization showed that silver nanoparticles were spherical, ranging from 5 to 20 nm and had an average hydrodynamic size distribution of 100.8 nm. In conclusion, leaf extract of Cordyline fruticosa (L.) A. Chev. can be utilized as a bioreductant and stabilizing agent, as indicated by stability test results, which showed considerable stability over a storage period of three months.

Silver nanoparticles have superior properties that attract much attention because they can increase their effectiveness and efficiency compared to their macroscopic size. Silver nanoparticles have several benefits, one of which is as an antibacterial agent. Synthesis of silver nanoparticles was carried out by reducing silver ions (Ag+) to uncharged silver (Ag0) using a reducing agent from Hibiscus sabdariffa Linn. petal extract. This research aims to synthesize silver nanoparticles by studying several parameters that influence their formation, such as the pH of Hibiscus sabdariffa Linn. petal extract, reaction time, silver nitrate concentration, and Hibiscus sabdariffa Linn. petal extract concentration. The silver nanoparticles formed were then tested for their antibacterial activity. The experimental results showed that the best synthesis was performed using Hibiscus sabdariffa Linn. petal extract with pH 10, reaction time of 45 minutes, silver nitrate concentration of 1×10-4 M, and Hibiscus sabdariffa Linn. petal extract concentration of 0.004%. The synthesized silver nanoparticles, examined through a transmission electron microscope, exhibited a size distribution ranging from 2 to 26 nm with an average size of 12 ± 3 nm, which was stable with a storage time of 3 months. Silver nanoparticles showed antibacterial activity against Staphylococcus aureus. Hibiscus sabdariffa Linn. petal extract is a promising reducing agent for producing antibacterial silver nanoparticles, showcasing its potential in this application.

Silver nanoparticles (AgNPs) have been synthesized using Rhoeo discolor leaf extract as a reducing and stabilizing agent. AgNPs were synthesized by adding silver nitrate to the extract of Rhoeo discolor and incubating it in a boiling water bath. The change in color of the mixture from clear to yellow indicated AgNPs formation. The synthesized AgNPs were spherical and showed an absorption peak at around 410-420 nm. The size of particles was distributed from 92 to 485 nm with an average size of 176 nm, and the polydispersity index was 0.185. The stability test showed that synthesized AgNPs were stable for three months of storage at ambient temperature. The extract of Rhoeo discolor were responsible for reducing silver ion and stabilizing the synthesized AgNPs.

Deep eutectic solvent (DES) has high viscosity and electrical conductivity values, so it can be used as an electrolyte solvent in dye-sensitized solar cells (DSSCs). This research was conducted to produce DES based on choline chloride (ChCl) and ethylene glycol (EG), diethylene glycol, and polyethylene glycol-400, which were then used as KI/I2 couple redox electrolyte solvent to improve the DSSC performance. The synthesis was carried out by mixing each component in several variations of the mole fraction of ChCl (xCHCl) at 80 °C for 15 min, and then was characterized by their pH, freezing point, density, viscosity, and electrical conductivity. A mixture that meets the criteria as a eutectic solvent and has a freezing point of less than −18 °C with the highest electrical conductivity value is DES ChCl:EG with xChCl 0.3 and xChCl 0.4. Both DESs were then used as a solvent for KI/I2, combined with acetonitrile in various compositions. The electrolyte with the highest electrical conductivity value was KI/I2 dissolved in ChCl:EG with xChCl 0.3 solvent 6:4 v/v, and then employed in DSSC device. The best performance of DSSC (Isc= 0.155 mA/cm2; Voc=0.465 V; Pmax= 0.719 W; ηmax= 0.072%) was produced under a light intensity of 0.1 W/cm2.

Groundwater in peatlands has the potential to be utilized as a water source, but its high organic matter content presents challenges. This study aimed to improve the quality of peat water through the adsorption of organic matter using chitosan magnetic beads composite adsorbent. Magnetic chitosan beads (KMB) composite was synthesized by mixing chitosan, acetic acid, and a mixture of Fe2+/Fe3+ solution with a mole ratio of 1:2. This mixture was then dropped into a sodium hydroxide solution. In addition to KMB, magnetic composite beads containing glutaraldehyde crosslinking agent (KMBG) were also synthesized. The results of composites analysis using a Fourier transform infrared (FTIR) spectrophotometer showed typical Fe-O absorption bands at 582 cm-1 and 578 cm-1 for KMB and KMBG. The typical C=N absorption band for glutaraldehyde in KMBG appeared at 1631 cm-1. X-ray diffraction (XRD) analysis revealed the characteristic peaks of Fe3O4 for KMB and KMBG at 2θ = 30.2°, 35.5°, 43.2°, 57.0°, and 62.8° with an amorphous structure. The adsorption of organic matter was performed by varying the pH (2, 3, 4, and 5) of peat water and the mass of the adsorbent (50, 70, 100, 200, and 300 mg). The optimum adsorption occurred at pH 2 with an absorbent mass of 0.1 g KMB and 0.07 g KMBG. Applying KMB on peat water reduces turbidity, color, and absorbance at a wavelength of 254 nm (Aλ=254), which is better than using KMBG. These three parameters’ efficiency percentages were 44%, 78%, and 74% for KMB and 17%, 30%, and 59% for KMBG.

Premna serratifolia Linn. leaf extract has been used as a reducing agent in the synthesis of silver nanoparticles (AgNPs). Various synthesis parameters such as reaction time, concentration and the pH of the Premna serratifolia Linn. leaf extract, and silver nitrate concentration were investigated. In addition, the stability of synthesized AgNPs and their activity against Staphylococcus aureus and Escherichia coli have also been investigated. The results of the experiment showed that Premna serratifolia Linn. leaf extract reduced silver ions resulting in AgNPs. In addition, the AgNPs colloid showed a gradual change in color from transparent green to yellow. At the same time, its ultraviolet (UV)-Visible spectra exhibited the typical surface plasmon resonance peak at around 400-415 nm. The optimum reaction conditions in the formation of AgNPs are 40 minutes of reaction time using silver nitrate 1.5x10-4 M and Premna serratifolia Linn leaf extract 80 ppm at pH 10. The particle size of synthesized AgNPs distributes from 48.3-157 nm with an average size of 58.7±14.4 nm and is stable at least for 1-month storage under ambient conditions. The antibacterial test shows that synthesized AgNPs are effective against both Escherichia coli and Staphylococcus aureus.

Nostalgia Sebuah Kota adalah sebuah pertunjukan teatrikal yang dibangun dari unsur-unsur ekspresi tubuh simbolik dan berbagai dialog puitis. Hal ini membedakan pertunjukan dengan pertunjukan teater, yang umumnya secara konvensional menghadirkan tubuh sehari-hari dan dialog prosaik, dekat dengan realitas kehidupan sehari-hari. Artikel ini dimaksudkan untuk menyelidiki pertunjukan untuk menemukan konsep di balik pilihan idiom dan ekspresi khusus ini. Pertunjukan didekati dengan teori teater pasca-dramatis Hans-Thies Lehmann, di mana deskripsi teater tidak lagi ditujukan untuk menjelaskan karakter, tema, dan plot, tetapi konstruksi lima komponen baru, yaitu: teks; ruang; waktu; tubuh; dan media. Menerapkan metode analisis deskriptif, dengan data yang diperoleh dari studi teks, wawancara naratif, dan studi dokumentasi, hasil penelitian menunjukkan bahwa Nostalgia Sebuah Kota adalah sebuah pertunjukan yang dipicu dari penggalan-penggalan puisi. Iswadi Pratama memilih daya puitis sebagai sutradara yang juga penyair, untuk memperluas ekspresi puisi yang ditulisnya. Berdasarkan proses eksplorasi puisi tersebut, Nostalgia Sebuah Kota kemudian menghasilkan tiga produk sekaligus, yaitu teks pertunjukan, teks drama, dan teks puisi baru.

Isolation of cellulose in empty fruit bunch (EFB) is hindered by lignin content. EFB was pretreated with Pleurotus ostreatus which has the ability to degrade lignin, in various incubation times (0th, 15th,30th, 45th, and 60th). The result showed lignin and cellulose decreased from 29.3% to 20.3% and from 40.2% to 26.2%, respectively. The optimum degradation time was on 30th day in which lignin and cellulose contents decreased from 29.3% to 20.3% and from 41% to 39.7% respectively. The cellulose to lignin (C/L) ratio increased from 1.40 to 1.99. These data revealed that P. ostreatus have a high potential for EFB delignification.

Silver nanoparticles are known to play a crucial role in various fields, prompting researchers to undertake synthesis and modification to obtain nanoscale particles. Silver nanoparticles were synthesized using a green synthesis-based chemical method with an extract from Cordyline fruticosa (L.) A. Chev. This study aims to determine the optimum conditions, including pH parameters, reaction time, and concentration, and assess the silver nanoparticles' stability and characteristics. The research findings revealed that the optimal conditions for synthesizing silver nanoparticles were an extract pH of 11, a reaction time of 60 minutes, a AgNO3 concentration of 1.5 x 10-4 M, and an extract concentration of 0.008%. Characterization showed that silver nanoparticles were spherical, ranging from 5 to 20 nm and had an average hydrodynamic size distribution of 100.8 nm. In conclusion, leaf extract of Cordyline fruticosa (L.) A. Chev. can be utilized as a bioreductant and stabilizing agent, as indicated by stability test results, which showed considerable stability over a storage period of three months. [ABSTRACT FROM AUTHOR]

Highly stable silver nanoparticles capped with p-hydroxybenzoic acid were synthesized by reducing silver ion with p-hydroxybenzoic acid and used for the detection of paraquat. The synthesized silver nanoparticles, which are yellow, exhibited an absorption peak at 420 nm when measured with a UV-visible spectrophotometer due to the surface plasmon resonance. In the presence of paraquat, the color of silver nanoparticles changed from yellow to purple accompanied by the appearance of a new peak at 580 nm in addition to the peak at 420 nm. In order to obtain optimum experimental conditions, temperature, and time of reaction were optimized, and the ratio of absorbance obtained at 580 nm and 420 nm (A580/A420) were monitored. The A580/A420 is proportional to the concentration of paraquat. Under the most favorable condition, the calibration curve showed a high level of linearity ranging from 6.0 × 10–4 to 1.0 × 10–3 M, and the detection limit was found to be 8.30 × 10–6 M. Silver nanoparticles capped with p-hydroxybenzoic acid was found to be useful for the colorimetric determination of paraquat in the aqueous medium.

In this paper, we report for the first time thesimple method for detection of Hg(II) ion in anaqueousmedium using silver nanoparticles capped with 3-hydroxybenzoic acid. Silver nanoparticles capped with 3-hydroxybenzoic acid were preparedby reduction of the silver ion with 3-hydroxybenzoic acid and without surface functionalization. The formation of silver nanoparticles was characterized by a UV-Visible spectrophotometer. The yellowcolloid of prepared silver nanoparticles capped with 3-hydroxybenzoic acid showed a surface plasmon resonance peak at 420 nm. The ability of silver nanoparticles capped with 3-hydroxybenzoic acid in detection was tested by doing a reaction with several metal ions individually(Na(I), K(I), Cu(II), Zn(II), Ca(II), Mg(II), Hg(II), Mn(II), Ni(II), Pb(II), and Co(II)). It was foundthat silver nanoparticles capped with 3-hydroxybenzoic acid highly selective toHg(II) and then the prepared silver nanoparticles were developedfor detection of Hg(II) ion. Addition of 1 mL Hg(II) ion into 4mL the as-preparedsilver nanoparticles reducedthe peak of surface plasmon resonance spectra, andthe reduction of peak intensity was proportional to the concentration of Hg(II) ion. A goodlinear relationship (R2= 0.998) between absorbance at 420 nm and concentrationof Hg(II) over the range 1.0x10-3to 5.5x10-3M was obtained. Silver nanoparticles capped with 3-hydroxybenzoic acid were highly sensitive to Hg (II) ion with the detection limit down to 4.7x10-5M. Application the method to the real water sample showed the excellentresult with recovery ranged from 98 to 101%. The proposed method was found to be useful forthe colorimetric detection of Hg(II) ion in an aqueousmedium.

Silver nanoparticles capped with m-hydroxybenzoic acid and p-hydroxybenzoic have been successfully synthesized, but the long-term stability data of these silver nanoparticles are not available. In this paper, we report the stability of these two types of silver nanoparticles for a period of 40 weeks observation based on the change of surface plasmon resonance spectra of silver nanoparticles. Silver nanoparticles were synthesized by reduction of silver nitrate with m-hydroxybenzoic acid and p-hydroxybenzoic acid without addition of capping agent. The presence of silver nanoparticles was indicated by the appearance of yellow color due to the surface plasmon resonance of silver nanoparticles. The resulted silver nanoparticles were stored at room temperature and further UV-visible spectrophotometer was used to follow the change in surface plasmon resonance spectra. The surface plasmon resonance spectra of silver nanoparticles were overlapped for the first 18 weeks, followed by little change in the position of absorption maxima (lmax), peak intensity, and width of the absorption peak until the week of 40. Silver nanoparticles capped with m-hydroxybenzoic acid and silver nanoparticles capped with p-hydroxybenzoic acid were highly stable which should make them suitable for further applications. The results show the potential of m-hydroxybenzoic acid and p-hydroxybenzoic acid to become a new reducing agent in the synthesis of highly stable silver nanoparticles. The m-hydroxybenzoic acid and p-hydroxybenzoic acid appeared to act as both reducing and capping agent.

Silver nanoparticles (AgNPs) have been synthesized using Rhoeo discolor leaf extract as a reducing and stabilizing agent. AgNPs were synthesized by adding silver nitrate to the extract of Rhoeo discolor and incubating it in a boiling water bath. The change in color of the mixture from clear to yellow indicated AgNPs formation. The synthesized AgNPs were spherical and showed an absorption peak at around 410-420 nm. The size of particles was distributed from 3 to 18 nm with an average size of 8 ± 2 nm, and the polydispersity index was 0.185. The stability test showed that synthesized AgNPs were stable for three months of storage at ambient temperature. The extract of Rhoeo discolor were responsible for reducing silver ion and stabilizing the synthesized AgNPs. [ABSTRACT FROM AUTHOR]

Effect of pH and determination of adsorption capacity of Cu(II), Ni(II) and Pb(II) heavy metal ions on adsorbent prepared from Eichhornia crassipes (eceng gondok) biomass has been investigated. The influence of media acidity on the adsorption characteristics was carried out by determining ions adsorbed at various pH in the range of 2-10, while an adsorption isotherm model of Langmuir was used to estimate the capacity of adsorption. Results showed that Cu(II) was optimally adsorbed at the range pH of 5-6, Ni(II) at 2-4, while Pb(II) reached an optimum adsorption at pH 2-3. The adsorption data of Cu(II), Ni(II) and Pb(II) for the adsorbent folowed quite well Langmuir isotherm model, confirmed that such chemisorptions involved on that process. The ions adsorption capacities (am) were 27.47, 16.69, and 15.04 mg/g for Pb(II), Cu(II), and Ni(II), respectively. Keywords: adsorption, heavy metal, Eichhornia crassipes, pH, capacity

Isolation of cellulose in empty fruit bunch (EFB) is hindered by lignin content. EFB was pretreated with Pleurotus ostreatus which has the ability to degrade lignin, in various incubation times (0th, 15th,30th, 45th, and 60th). The result showed lignin and cellulose decreased from 29.3% to 20.3% and from 40.2% to 26.2%, respectively. The optimum degradation time was on 30th day in which lignin and cellulose contents decreased from 29.3% to 20.3% and from 41% to 39.7% respectively. The cellulose to lignin (C/L) ratio increased from 1.40 to 1.99. These data revealed that P. ostreatus have a high potential for EFB delignification. [ABSTRACT FROM AUTHOR]