PEMANFAATAN LIMBAH KULIT BUAH COKELAT SEBAGAI BIOETHANOL

Ketersediaan limbah kulit cokelat dapat diperoleh secara kontinyu dan melimpah, merupakan salah satu limbah yang kurang dimanfaatkan. Kulit cokelat hanya digunakan sebagai makanan ternak. Tetapi kulit cokelat mempunyai kadar selulosa dan glukosa yang dapat digunakan sebagai salah satu bahan penghasil ethanol. Penelitian produksi bioethanol dari kulit buah cokelat bertujuan untuk mencari bahan baku alternatif bioethanol. Dalam penelitian produksi bioethanol dari kulit cokelat dilakukan proses hidrolisis pada kondisi tetap : suhu 30 oC, air 700 ml, waktu hidrolisis 1 hari dan kondisi berubah: berat kulit cokelat 25, 30, 35, 40, 45, (gram), larutan HCl sampai pH 1, 2, 3, 4, 5. Kemudian dilanjutkan proses fermentasi pada kondisi tetap: suhu 30 oC ; pH 4,5 ; volume fermentasi 200 ml ; starter 10 % dan kondisi berubah: waktu fermentasi 2, 3, 4, 5, 6, 7 (hari). Dari penelitian produksi bioethanol dari kulit cokelat diperoleh hasil, pada proses hidrolisis kadar glukosa yang terbaik 25,5 %, berat kulit cokelat 25 gram. Pada proses fermentasi kondisi terbaik dengan starter Saccharomyces Cerevisiae 10 % selama 6 hari, menghasilkan bioethanol sebesar 10,90 % dan kadar glukosa sisa 1,05 %

Studi Kasus Supervisi Akademik di SMP

The purpose of this research is to know, understand, describe in detail, and deep understanding of program planning, implementation, and follow-up of the academic supervision in SMP Negeri 3 Semparuk District of Sambas district. This study used a qualitative approach through case studies, as the research subjects are the principal, vice-principal, two senior teachers, and ten domestic and honorary teachers and one-supervisor junior coaches. Data is collected by using observation, interview, and documentation. The findings of this study are the planning in academic supervision conducted by principals, vice-principal, and senior teachers do not involve all the relevant components that affect the success of academic supervision programs. The implementation of academic supervision involving principals and senior teachers use the direct method. The follow-up of the supervision are directing and reinforcing only. From the findings, the activities in the academic supervision conducted by the subjects are not effective ways to achieve the better result in instruction

Impact of Programming Features on Code Readability

Readability is one important quality attributes for software source codes. Readability has also significant relation or impact with other quality attributes such as: reusability, maintainability, reliability, complexity, and portability metrics. This research develops a novel approach called Impact of Programming Features on Code Readability (IPFCR), to examine the influence of various programming features and the effect of these features on code readability. A code Readability Tool (CRT) is developed to evaluate the IPFCR readability features or attributes. In order to assess the level if impact that each one of the 25 proposed readability features may have, positively or negatively on the overall code readability, a survey was distributed to a random number of expert programmers. These experts evaluated the effect of each feature on code readability, based on their knowledge or experience. Expert programmers have evaluated readability features to be ordered then classified into positive and negative factors based on their impact on code readability or understanding. The survey responses were analyzed using SPSS statistical tool. Most of proposed code features showed to have significantly positive impact on enhancing readability including: meaningful names, consistency, and comments. On the other hand, fewer features such as arithmetic formulas, nested loops, and recursive functions showed to have a negative impact. Finally, few features showed to have neutral impact on readability

Vibration suppression of the horizontal flexible plate using proportional– integral–derivative controller tuned by particle swarm optimization

This paper presents the development of an active vibration control for vibration suppression of the horizontal flexible plate structure using proportional–integral–derivative controller tuned by a conventional method via Ziegler–Nichols and an intelligent method known as particle swarm optimization algorithm. Initially, the experimental rig was designed and fabricated with all edges clamped at the horizontal position of the flexible plate. Data acquisition and instrumentation systems were designed and integrated into the experimental rig to collect input–output vibration data of the flexible plate. The vibration data obtained through experimental study was used to model the system using system identification technique based on auto-regressive with exogenous input structure. The plate system was modeled using particle swarm optimization algorithm and validated using mean squared error, one-step ahead prediction, and correlation tests. The stability of the model was assessed using pole zero diagram stability. The fitness function of particle swarm optimization algorithm is defined as the mean squared error between the measured and estimated output of the horizontal flexible plate system. Next, the developed model was used in the development of an active vibration control for vibration suppression on the horizontal flexible plate system using a proportional–integral–derivative controller. The proportional–integral–derivative gains are optimally determined using two different ways, the conventional method tuned by Ziegler–Nichols tuning rules and the intelligent method tuned by particle swarm optimization algorithm. The performances of developed controllers were assessed and validated. Proportional–integral–derivative-particle swarm optimization controller achieved the highest attenuation value for first mode of vibration by achieving 47.28 dB attenuation as compared to proportional–integral–derivative-Ziegler–Nichols controller which only achieved 34.21 dB attenuation

Travelling-wave similarity solutions for an unsteady shear-stress-driven dry patch in a flowing film

We investigate unsteady flow of a thin film of Newtonian fluid around a symmetric slender dry patch moving with constant velocity on an inclined planar substrate, the flow being driven by a prescribed constant shear stress at the free surface of the film (which would be of uniform thickness in the absence of the dry patch). We obtain a novel unsteady travelling-wave similarity solution which predicts that the dry patch has a parabolic shape and that the film thickness increases monotonically away from the dry patch

DAMPAK DAN PENGENDALIAN HUJAN ASAM DI INDONESIA

Hujan asam ialah turunnya asam dalam bentuk hujan. Hal ini terjadi apabila asam di udara larut dalam butirbutir air di awan. Jika hujan turun dari awan itu, air hujan bersifat asam. Asam itu terhujankan atau rainout. Hujan asam dapat pula terjadi karena hujan turun melalui udara yang mengandung asam sehingga asam itu terlarut kedalam air hujan dan turun kebumi

The development of the law of the sea in relation to Malaysia

Freedom of the seas existed during the Melaka Sultanate. When the Portugese and leter the Dutch occupied Melaka, the seas were treated as mare clausum. The concept of the territorial sea was evolved during British Colonial period. Conventional rules of the law of the sea applied to Malaysia by accessions to the relevant conventions. The law of the sea also developed through unilateral claims, bilateral treaties and legislations. The Statement relating to Article 233 of the Convention on the law of the sea may develop into a special legal regime perculiar to the Straits of Malacca and Singapore

ANALISIS KINERJA KEUANGAN SEBELUM DAN SESUDAH PANDEMI COVID-19 PADA PT. MEDIA NUSANTARA CITRA, Tbk PERIODE 2018-2021

This study aimed to determine the differences in financial performance before and after the COVID-19 pandemic at PT. Media Nusantara Tbk for the 2018-2021 period. This study used quantitative research with financial ratios: Current Ratio, Debt to Equity Ratio, Return on Asset, Debt to Total Asset Ratio, and Total Asset Turnover. The data analysis method used was paired sample t-test. This study found that the current ratio after the Covid-19 pandemic is higher, with a larger average than before the Covid-19 pandemic. On the other hand, the Return on Assets before the Covid-19 pandemic was higher with a larger average than after the Covid-19 pandemic Total Asset Turnover was higher before the Covid-19 pandemic with a smaller average than after the Covid-19 pandemic. Moreover, the Debt to Equity was higher before the pandemic, and the Debt to Total Asset Ratio was higher with a smaller average than during the pandemic. In conclusion, there was no significant difference between the Current Ratio, Return on Asset, and Total Asset Turnover. However, there was a significant difference between the Debt to Total Asset Ratio and the Debt-to-Equity Ratio

Konstelasi Relasi Antar Aktor dalam Gerakan Penolakan Tambang Emas di Desa Pace Kecamatan Silo Kabupaten Jember 2016

This study aimed to analyze the movements and actors in the resistance movement of gold mining in the Pace village Subdistrict Silo, Jember regency. This research was using the Qualitative method include in-depth interviews and field in research studies,In addition collecting documents related to this research. This research had resulted, in finding the relationships between actors prone to be a trigger of conflict and led to the refusal movement made by the village community of Pace. Conflict of individuals who had an influence that made this conflict had became a mass conflict involving the community at large. Meantime, besides individual behalf, the state also had behalf for mining through PT Antam. The presence of the state in gold mining in the Pace village had become new chapter to the people who reject gold mining in the Pace village