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"Ion Cr(III) merupakan spesies logam yang berbahaya bagi manusia dan lingkungan. Konsentrasi ion Cr(III) yang berlebih dalam tubuh manusia dapat menyebabkan penyakit seperti kardiovaskular dan penyakit mata. Karenanya metode deteksi yang sensitif dan selektif sangat dibutuhkan. Pada penelitian ini, dikembangkan deteksi ion Cr(III) berbasis fenomena electrochemiluminescence (ECL) menggunakan luminol sebagai luminofor pada elektroda boron-doped diamond (BDD). Dalam sistem ECL luminol yang digunakan, hidrogen peroksida ditambahkan sebagai koreaktan untuk meningkatkan reaksi ECL pada permukaan elektroda. Penambahan Cr(III) ke dalam sistem luminol-hidrogen peroksida menunjukkan penurunan intensitas sinyal ECL dari sistem. Optimasi menunjukkan bawa pada pH 9, konsentrasi hidrogen peroksida 25 mM, konsentrasi luminol 1 mM, laju pindai 100 mV/s, dan dalam atmosfer nitrogen, sinyal ECL berkurang secara linier dengan meningkatnya konsentrasi Cr(III) pada rentang konsentrasi 0 ppm hingga 0,1 ppm dengan nilai LOD sebesar 0,0095 ppm, LOQ sebesar 0,0316 ppm, dan sensitivitas sebesar 315,706 a.u ppm-1 cm-2. Keberulangan yang baik ditunjukkan dengan RSD sebesar 2,01% pada 10 kali pengulangan. Sensor ECL yang dikembangkan juga menunjukkan selektivitas yang baik terhadap ion Cr6+, Cd2+, dan Fe3+. Hasil pengukuran terhadap matriks air keran menujukkan persen perolehan kembali yang baik sekitar 83—99% menunjukkan bahwa metoda yang dikembangkan menjanjikan untuk pengembangan sensor Cr(III) berbasis ECL luminol pada berbagai sampel air.

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Cr(III) ion is a metal species that is harmful to humans and the environment. Excessive concentration of Cr(III) ions in the human body can cause diseases such as cardiovascular and eye diseases. Therefore, a sensitive and selective detection method is needed. In this research, the detection of Cr(III) ions based on the phenomenon of electrochemiluminescence (ECL) was developed using luminol as a luminophore on boron-doped diamond (BDD) electrodes. In the luminol ECL system used, hydrogen peroxide is added as a corectant to enhance the ECL reaction on the electrode surface. The addition of Cr(III) into the luminol-hydrogen peroxide system showed a decrease in the intensity of the ECL signal from the system. The optimization shows that at pH 9, hydrogen peroxide concentration 25 mM, luminol concentration 1 mM, scan rate 100 mV/s, and in a nitrogen atmosphere, the ECL signal decreases linearly with increasing Cr(III) concentration in the concentration range of 0 ppm to 0.15 ppm with a LOD value of 0.0095 ppm, a LOQ of 0.0316 ppm, and a sensitivity of 315.706 a.u ppm-1 cm-2. Good repeatability is indicated by an RSD of 2.01% at 10 repetitions. This ECL sensor also shows good selectivity towards Cr6+, Cd2+, and Fe3+ ions. The measurement results on the tap water matrix showed a good recovery percentage of around 83—99% indicating that the developed method is promising for developing Cr(III) sensors based on ECL luminol on various water samples."

"This is one of the first texts in which electro-diffusion of ions in its different aspects is considered as a unified subject. As a subject it is relevant to understanding the behavior of apparently different physical objects such as electrolyte solution, ion-exchangers, ion-selective membranes, and semiconductors. This text treats a selection of topics in electro-diffusion of ions in an aqueous medium --- a nonlinear transport process whose essence is diffusion of ions combined with their migration in a selfconsistent electric field. Electro-Diffusion of Ions is intended to enhance the understanding of particular electro-diffusional transport phenomena and to spark the interest of the mathematical community in the corresponding area of applications and development of a unified scientific vision. Contains some previously unpublished results for electro-diffusional problems."

"Pengembangan baterai listrik sebagai sumber energi utama untuk electricity-vehicle menjadi fokus utama dalam industri otomotif terkini. Salah satu dari sumber energi listrik yang paling banyak dikembangkan adalah baterai ion lithium. Komponen penting pada Baterai Ion-Lihium yakni katoda merupakan salah satu komponen yang banyak dilakukan pengembangan pada bidang industri, katoda yang paling banyak digunakan pada pengembangan industri baterai ion-lihium adalah LiCoO2 dan NMC 622. NMC material memiliki keuntungan dibandingkan LiCoO2 terutama dalam keseimbangan energy density, power capability, dan cost dari produk. Material NMC juga memiliki kesetimbangan termal yang lebih baik dibandingkan LiCoO2 sehinga lebih safety dalam proses sintesis material. Penelitian kali ini, menggunakan NMC 622 sebagai katoda utama dengan disintesis menggunakan metode solution combustion (SCS) dengan variasi suhu sintering. Metode solution combustion digunakan karena metode ini sederhana dalam pengunaannya, cost yang cenderung murah, dan proses sintesis tidak memakan waktu yang lama. Untuk mendapatkan data penelitian, mengenai performa terbaik pada hasil sisntesis dilakukan variasi suhu sintering pada 3 variasi suhu 700 oC, 800 oC, dan 900 oC. Hasil dari uji SEM-EDS menyatakan bahwa material memiliki distribusi partikel yang baik. Hasil XRD menunjukkan hasil struktur material yang berbentuk hexagonal. NMC 622 800 oC memiliki kapasitas 137.24787 mAh/g, NMC 622 700 oC sebesar 101.56644 mAh/g dan kapasitas NMC 622 900 oC sebesar 66.61218 mAh/g.

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The development of electric batteries as the main energy source for electricity-vehicles is a major focus in the current automotive industry. One of the most widely developed sources of electrical energy is the lithium-ion battery. An important component in the Ion-Lihium Battery, cathode is one of the components that is widely developed in the industrial field, the cathode that is most widely used in the development of the ion-lihium battery industry is LiCoO2 and NMC 622. NMC material has advantages over LiCoO2 especially in the balance of energy density, power capability, and cost of the product. NMC material also has a better thermal equilibrium than LiCoO2 so that it is more safety in the material synthesis process. This research uses NMC 622 as the main cathode by synthesizing it using the solution combustion (SCS) method with variations in sintering temperature. The solution combustion method is used because this method is simple in its use, the cost tends to be cheap, and the synthesis process does not take a long time. To obtain research data, regarding the best performance in the synthesis results, sintering temperature variations were carried out at 3 temperature variations of 700 oC, 800 oC, and 900 oC. The results of the SEM-EDS test state that the material has a good particle distribution. XRD results show the results of hexagonal material structure. NMC 622 800 oC has a capacity of 137.24787 mAh/g, NMC 622 700 oC of 101.56644 mAh/g and a capacity of NMC 622 900 oC of 66.61218 mAh/g."

"Metal ions in the brain are a necessity as well as a poison. The presence of metal ions in the active sites of biological catalysts or metalloproteins and in the biological functioning of nucleic acids is very well documented and they are required for brain activity. On the other hand, metals are very effective in generating oxidative stress. This effect does not only play a role in immunology but also is the root of practically all neurodegenerative disorders by inducing disease via the death of neurons. Managing metal ions in the brain could therefore be an important strategy in the search for therapeutic agents used in the treatment of neurodegenerative diseases. This new title gives an overview to key topics in the area of metal ions in the brain. It focuses on the role of metal ions in neurological systems by describing their advantageous functions as well as their poisonous features. It is therefore of interest for scientists in biochemistry and biophysics, physiology, toxicology as well as for physicians focused on this topic."

"Deteksi hidrogen peroksida (H2O2) berhasil dikembangkan dengan metode luminol electrochemiluminescence (ECL) pada permukaan screen-printed carbon electrode (SPCE) yang dimodifikasi dengan partikel emas. ECL luminol diperoleh dari  oksidasi luminol menghasilkan spesies 3-aminoftalat tereksitasi yang kemudian berelaksasi dengan memancarkan intensitas cahaya. H2O2 bertindak sebagai ko-reaktan pada ECL luminol karena hasil oksidasi elektrokimia H2O2 pada permukaan elektroda menghasilkan radikal hidroksil (OH•), yang dapat meningkatkan oksidasi luminol dan akibatnya meningkatkan sinyal ECL luminol. Modifikasi dengan partikel emas di permukaan SPCE dilakukan karena partikel emas memiliki kelebihan yaitu; luas permukaan yang besar, konduktivitas yang sangat baik, dan aktivitas katalitik yang baik terhadap oksidasi H2O2 untuk menghasilkan radikal hidroksil (OH•) yang distabilkan oleh interaksi pertukaran elektron parsial. Teknik voltametri siklik yang digunakan untuk menghasilkan oksidasi H2O2 dan oksidasi luminol yang menghasilkan ECL menunjukkan hubungan linear (R2 = 0,9995) pada rentang konsentrasi H2O2 0,5 µM hingga 200 µM. Sensor yang dikembangkan menunjukkan hasil performa yang baik dengan batas deteksi sebesar 4,78 µM, dan dapat digunakan untuk mendeteksi sampel H2O2 dalam matriks susu dan air keran.

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Hydrogen peroxide (H2O2) detection was successfully developed by electrochemiluminescence (ECL) luminol method at a screen-printed carbon electrode modified with gold nanoparticles (AuNPs-SPCE). The ECL detection mechanism follows the oxidation of H2O2 to hydroxyl radicals (OH•) acting as a co-reactant to increase the ECL signal by inducing oxidized luminol to produce an excited species of 3-aminophthalate then relaxes and emits a luminous intensity on the electrode surface. AuNPs was deposited to SPCE due to feature high surface area, excellent conductivity, and good catalytic activity towards H2O2 oxidation to produce hydroxyl radicals (OH•) which stabilized by partial electron exchange interactions. Cyclic voltammetry (CV) technique was used for the ECL measurements which showed liner relationship (R2 = 0.9995) in the range 0.5 to 200 µM of H2O2 concentrations. The developed sensor showed a good perform with an estimated detection limit of 4.78 µM, and applicable for real sample detection of H2O2 in milk and tap water."

"Modifikasi elektroda emas adalah salah satu metode alternatif yang dapat digunakan sebagai sensor kimia untuk analisis ion logam Cu²⁺. Modifikasi elektroda emas dilakukan dengan cara mengimobilisasi 3-mercaptopropionic acid pada permukaan elektroda emas dengan metode self assembled monolayer (SAM) yang difungsionalisasikan dengan EDTA. Karakterisasi elektroda emas dilakukan dengan teknik cyclic voltametry (CV), fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) dan energy dispersive spectrometer (EDS). Luas elektroda yang digunakan adalah 0,809 cm². Modifikasi dan aplikasi sensor elektroda Au-Bare, Au-3MPA dan Au-3MPA-EDTA terhadap pendeteksian ion logam Cu²⁺ telah berhasil dilakukan. Puncak arus oksidasi ion logam Cu²⁺ tertinggi terdapat pada pH 5 antara lain, 8,07 x 10^-5A  pada elektroda Au-3MPA-EDTA, 5,92 x 10^-5A pada elektroda Au-3MPA dan 7,42 x 10^-5A pada elektroda Au-Bare pada kisaran potensial 0,35 V.

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Modification of the gold electrode is an alternative method that can be used as a chemical sensor for the analysis of Cu²⁺ metal ions. Modification of the gold electrode was carried out by immobilizing 3-mercaptopropionic acid on the surface of the gold electrode using the self assembled monolayer (SAM) method which was functionalized with EDTA. Gold electrode characterization was performed by cyclic voltametry (CV), fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS) techniques. The electrode area used is 0.809 cm². Modifications and applications of Au-Bare electrode sensors, Au-3MPA and Au-3MPA-EDTA against the metal ion detection of Cu²⁺ have been successfully performed. The top of the current Cu²⁺ metal ion oxidation state is found in pH 5 among others, 8.07 x 10^-5 A on Au-3MPA-EDTA electrodes, 5.92 x 10^-5 A on Au-3MPA electrodes and 7.42 x 10^-5 A on Au-Bare electrodes at a potential range of 0.35 V."