Analisis Pengaruh Urea terhadap Kestabilan Kompleks Humat–besi pada Lapisan Tanah

Substansi organik dalam tanah dapat menyebabkan terbentuknya kompleksdengan ion logam. Asam humat yang merupakan salah satu substansi tanahberperan dalam transportasi ion-ion tersebut, sehingga dapat membentukkompleks ion logam melalui reaksi pembentukan kompleks. Penelitian inibertujuan menentukan konstanta stabilitas kompleks humat-besi danpengaruhnya dengan penambahan urea pada variasi konsentrasi terhadapkestabilan kompleks tersebut. Asam humat yang diperoleh dengan cara ekstraksidari tanah, mempunyai bobot molekul (BM) 17,987, spekturm inframerahmenunjukkan gugus karboksil, fenolik, dan karbonil. Dan spektrum ultravioletvisibelmemberi rasio warna (E4/E6) sebesar 5,47. Konstanta stabilitas humat-besisebesar 0,046. Penambahan urea akan mempengaruhi harga konstanta stabilitaskompleksnya. Penambahan urea yang akan memperbesar nilai konstantastabilitas tersebut, mempunyai nilai minimum sebesar 0,04 N

Photocatalytic Production of Tio2-natural Zeolite From Tasikmalaya for Photodegradation of Methylene Blue

Photocatalyst is reaction process of one materials to another materials which aided by energy from ultraviolet radiation and solid catalyst. The study conducted by making a catalyst based on variation concentrates from natural zeolite Cikalong-Tasikmalaya with addition of TiO2. The test of photocatalytic activity was conducted on methylene blue. The purpose this study to obtain a new photocatalytic is modified of natural zeolite with TiO2 which expected had a high reactivity so able to used on waste fluid processing. The step was conducted were activated natural zeolite, than making of photocatalytic from TiO2 and natural zeolite, and the last is drying on the oven and calcination at 5000C. In the diffraction pattern of TiO2-zeolit (20%) there was a peak of TiO2 around of 2θ about 25,3o, it is indicated that TiO2 was surroundings on natural zeolite. TiO2-zeolit (20%) which was analyzed with SEM showed that active metal of TiO2 has been surroundings on surface of zeolite. Analysis of gas absorption (GSA) with BET methods showed an increase wide of 7,0 m2/g for zeolite and19,4 m2/g for TiO2-zeolit (20%). Best degradation of methylene blue was indicated by TiO2-zeolit (20%) with the value of 82,5% after the radiation with ultraviolet for 80 minutes and measured by visible UV spectrophotometer

A current review of TiO2 thin films: synthesis and modification effect to the mechanism and photocatalytic activity

Photocatalysts in the form of thin films such as TiO2 show great potential for various applications due to their ease of separation after use and their diverse synthesis processes. However, pure TiO2 has some intrinsic limitations, such as a wide bandgap (∼3.2 eV) which lowers its visible-light absorption and fast recombination of electrons and holes. Thus, it is necessary to modify TiO2 thin film to increase its photocatalysis efficiency and overcome these problems. This review examines reports over the past 10 years on TiO2 thin-film modification strategies using metal and non-metal modifiers with detailed possible mechanisms of modified TiO2 thin-film including optical modification and heterostructure formation. Recent advancements indicate that modifications can reduce the band gap 0.14–0.85 eV lower compared to pure TiO2 and several modified photocatalysts can degrade >90 % of pollutant molecules. This review also highlights the effect of synthesis methods such as sol-gel, hydrothermal, magnetron sputtering, atomic layer, and chemical vapor deposition on the film properties. The different methods lead to different properties including morphology, defects, optical properties, crystal structure, and roughness. This review aims to provide a comprehensive understanding of synthesis methods, mechanisms, and performance enhancements, offering insights into the future design of high-efficiency TiO2 thin film-based photocatalysts

Mengenal Kanker Payudara Lebih Dekat

Kanker payudara merupakan salah satu penyakit yang banyak dihadapi oleh perempuan di berbagai belahan dunia. Pemahaman yang tepat mengenai penyebab, gejala, serta langkah pencegahan dan pengobatan menjadi sangat penting dalam upaya deteksi dini dan penanganan yang lebih efektif. Mengenal Kanker Payudara Lebih Dekat adalah buku ajar yang dirancang untuk memberikan pemahaman komprehensif mengenai kanker payudara, mulai dari faktor risiko, tanda-tanda awal, hingga berbagai pilihan terapi yang tersedia. Buku ini juga membahas pentingnya deteksi dini, gaya hidup sehat, serta peran dukungan sosial dalam membantu pasien menghadapi perjalanan pengobatan. Buku ini disusun dengan bahasa yang jelas dan mudah dipahami sehingga dapat menjadi referensi bagi siapa saja yang ingin memahami kanker payudara secara lebih mendalam. Dengan pembahasan yang sistematis, buku ini dapat membantu meningkatkan kesadaran serta memberikan wawasan yang bermanfaat bagi pasien, keluarga, maupun masyarakat umum