THE EFFECT OF VERMICOMPOST ON THE GROWTH OF SOYBEAN (Glycine max L.)

The growth and production of soybean (Glycine max L) fertilized by vermicompost was conducted. The vermicompost used consisted of 4 levels, namely: K0 = no vermicompost, K1 = 60 g, K2 = 90 g and K3 = 120 g, each treatment was replicate 3 times. The results showed that the dose of vermicompost significantly affected to the number of branches, number of pods and seed weight, however the organic vertilizer not significantly affected on plant height, flowering age, number of empty pods and seeds dry weight. The interaction dose of vermicompost has no significant effect on plant height, number of branches, flowering age, number of pods, number of filled pods, number of seed and 100 seeds dry weight

Optimalisasi Metode Electroplatting Koagulasi Terhadap Penurunan Kadar Logam Zinkum (Zn) Pada Air Buangan Limbah Industri Pengolahan Karet

Penelitian tentang penggunaan metode electroplatting koagulasi untuk menurunkan konsentrasi logam Zn dalam air limbah industri karet telah dilakukan. Limbah yang digunakan memiliki karakteristik kontaminan Zn 1.2771 mg/L. Percobaan dilakukan dengan tegangan listrik 12 Volt, kuat arus 10 A, variasi waktu 0, 15, 30, 45, sampai 60 menit, variasi pH limbah 4, 7,dan 8, karakteristik plat elektroda dengan panjang 10 cm, lebar 2 cm dan ketebalan 0,5 mm, serta volume sampel sebanyak 1 liter dalam keadaan statis. Analisis Zn pada hasil akhir digunakan Spektrofotometer Serapan Atom (SSA). Hasil penelitian menunjukkan penurunan konsentrasi logam Zn pada pH 7 dengan waktu kontak 60 menit, yakni sebesar 99,56 %. Kata Kunci: electroplatting, koagulasi, zinkum, limbah, industri karet

AIR QUALITY MONITORING OF KALABAHI-ALOR’S SEAPORT-EAST OF NUSA TENGGARA

Evaluation of environment of seaport is needed as well as our responsibility to nature sustainability. The Alor’s seaport belongs to Pelindo III. In order to know the air quality of Alor’s seaport, we did this study. Our aims are to know level quality of air at Alor’s seaport and compare to the government regulation. This study refers to Pararosaniline (SOx), Saltzman (NOx), Particle Calculation (dust) and decibel (noisy) methods. We used four locations, those are A-1 (Entrance gate of PELINDO (8013’09.12”S, 124031’07.21”E)); A-2 (In front of passengers terminal (8013’08.75”S, 124031’01.60”E)); A-3 (Exit  gate Kalabahi’s seaport (8013’08.2”S, 124031’00.87”E)) and A-4 (In front of port of the people (8011’09.12”S, 124031’07.21”E)). Results show that the averages level of SOx, NOx and dust of A-1, A-2 and A-3 are 103.01, 104.65 and 107.47 (µg/Nm3), 37.87, 30.62, and 39.73 (µg/Nm3), 56.64, 47.47 and 50.72 (µg/Nm), respectively. On the other hand, the level of noisy of A-1, A-2, A-3 and A-4 are 68.76, 65.69, 65.20 and 73.60 (dBA), respectively. Base on all of data, we conclude that the air quality of Alor’s seaport is still appropriate according to government regulation (PP. No. 4, 1999)

The New Materials for Battery Electrode Prototypes

In this article, we present the performance of Copper (Cu)/Graphene Nano Sheets (GNS) and C—π (Graphite, GNS, and Nitrogen-doped Graphene Nano Sheets (N—GNS)) as a new battery electrode prototype. The objectives of this research are to develop a number of prototypes of the battery electrode, namely Cu/GNS//Electrolyte//C—π, and to evaluate their respective performances. The GNS, N—GNS, and primary battery electrode prototypes (Cu/GNS/Electrolyte/C—π) were synthesized by using a modified Hummers method; the N-doped sheet was obtained by doping nitrogen at room temperature and the impregnation or the composite techniques, respectively. Commercial primary battery electrodes were also used as a reference in this research. The Graphite, GNS, N—GNS, commercial primary batteries electrode, and battery electrode prototypes were analyzed using an XRD, SEM-EDX, and electrical multimeter, respectively. The research data show that the Cu particles are well deposited on the GNS and N—GNS (XRD and SEM—EDX data). The presence of the Cu metal and electrolytes (NH4Cl and MnO2) materials can increase the electrical conductivities (335.6 S cm−1) and power density versus the energy density (4640.47 W kg−1 and 2557.55 Wh kg−1) of the Cu/GNS//Electrolyte//N—GNS compared to the commercial battery (electrical conductivity (902.2 S cm−1) and power density versus the energy density (76 W kg−1 and 43.95 W kg−1). Based on all of the research data, it may be concluded that Cu/GNS//Electrolyte//N—GNS can be used as a new battery electrode prototype with better performances and electrical activities

Distribution model of iron (Fe) on Fe/Graphene nano sheets

In this paper, we report about the distribution model of Iron (Fe) atoms on Graphene Nano Sheets (GNS). The purpose of this research is to evaluate the performance of Fe/GNS in terms of the distribution of Fe atoms on the graphene surface. GNS and Fe/GNS were prepared with modified Hummer's and impregnation methods, respectively. We found that the morphology of graphite is different compare to GNS where GNS has thin layers and no stacking sheets (Scanning Electron Microscope (SEM) data) and it contains majority Carbon (C) element (more than 90 wt%) (EDX data). The X-Ray Diffraction (XRD) data of GNS shows the appearance weak and broad peak on 2θ = 26.6o indicating GNS was formed, and the sharp peaks on 2θ = 43.84o prove that Fe atoms are well deposited on GNS (XRD data). Both SEM and XRD data prove GNS produced and Fe deposited on GNS. Further, we propose the distribution model of Fe atoms on GNS surfaces based on three steps. The first step is the Fe precursor react with GNS to produce Fe ions. The second step is Fe ions reduce while being deposited on GNS surfaces, generating Fe clusters. Finally, Fe clusters migrate on the surfaces of GNS to form Fe particles. The smallest Fe crystal size in Fe/GNS is at 3.81% Fe (1.5009 nm) and distributed into GNS. Based on those data, GNS was found to affect the properties of Fe metal.All of the authors would like thank to Rector of Universitas Sumatera Utara - Indonesia who supporting this research under Scheme C, Program Penelitian Riset Kolaborasi Indonesia (RKI) 2022, Nomor 9420/ UN5.1.R/SK/PAP/2022