Kinerja Mesin Motor 4 Langkah dengan Bahan Bakar Campuran Bioetanol dan Pertamax

The availability of fossil fuels as an energy source is increasingly limited, so there is a need for new energy sources as environmentally friendly alternatives, one of which is bioethanol. Bioethanol is a type of biofuel sourced from living matter, usually plants with the chemical formula C2H5OH and the empirical formula C2H5O with an octane number of 108. One of the benefits of bioethanol for fuel mixtures is due to the higher octane value, flammability, heat of vaporization and higher oxygen content lowers cylinder temperature thereby reducing NOx emissions and producing less CO2. This study aims to evaluate the performance of a 4 stroke engine by comparing the use of Pertamax and bioethanol mixtures of fuel with a composition of 25%, 20%, and O% bioethanol. The study used an experimental method where data was collected and then data processing and data analysis were carried out. The results obtained the highest power of 8.70 kW at 25% bioethanol at 6000 rpm, followed by 20% bioethanol and 100% Pertamax at 8.60 rpm with rotations of 6500 rpm and 7000 rpm respectively. The highest torque of 25% bioethanol is 13.80 Nm at 5500 rpm, followed by 3.10 Nm at 5000 rpm at 100% pertamax and 12.80 Nm at 5500 rpm with 20% bioethanol fuel. The lowest fuel consumption is 0.57 kg/kWh at 7000 rpm with 100% pertamax fuel, then 0.60 kg/kWh with 20% bioethanol fuel at 6500 rpm and 0.6 kg/kWh with 15% bioethanol fuel at 6000 rp

Rancang Bangun Pendeteksi Curah Hujan Menggunakan Tipping Bucket Rain Sensor dan Arduino Uno

Curah hujan merupakan salah satu parameter hujan yang dapat diukur. Dimana curah hujan menyatakan seberapa besar tinggi air yang ditimbulkan oleh hujan di suatu daerah. Alat untuk megukur jumlah curah hujan yang turun kepermukaan tanah per satuan luas, disebut Penakar Curah Hujan. Curah hujan 1 (satu) milimeter, artinya dalam luasan satu meter persegi pada tempat yang datar tertampung air setinggi 1 (satu) milimeter atau tertampung air sebanyak 1 (satu) liter atau 1000 ml. Penakar hujan Tipping Bucket, nilai curah hujannya tiap bucket berjungkit tidak sama, serta luas permukaan corongnya beragam, misalnya ada yang 0.1 mm, 0.2 mm, 0.5 mm dan lain-lain. Dalam perancangan alat ini resolusi Tipping Bucket yang digunakan ialah 0.2 mm, dan juga memakai Modul Sensor Reed Switch. Reed Switch akan bekerja ketika magnet yang di tempel pada bagian tengah Tipping Bucket mendekati sensor Reed Switch, yang dimana Tipping Bucket akan bergerak disaat curah hujan masuk ke dalam corong dan akan ditampung pada Tipping Bucket yang membuat Tipping Bucket akan berjungkit. Kemudian Reed Switch akan mendeteksi magnet yang ada pada Tipping Bucket. Mikrokontroler berfungsi untuk membaca data dari Modul Sensor Reed Switch yang tiap kali ada sentuhan dari magnet

Agarose Coated Culture Plate in Tumorsphere Culture of Cervical Cancer Cell Line HeLa: an Alternative to Non Adhesive Culture Plate

Cervical cancer recurs in 90% cases and linked to cancer stem cells that able to self-renew and responsible for recurrence, metastasis, and mortality of cancer. Isolation and identification of cancer stem cells using serum-free medium needs expensive growth factors and consume time. This study try to grow tumor sphere using culture plate coated with 1% agarose as an efficient and economical alternative to non-adhesive culture plate. HeLa cell line was grew in culture plate coated with 1% agarose and non-adhesive culture plate using similar medium and culture condition. Tumor spheres morphology was observed and the colonies were counted in 7 days followed by single cell assay. Tumor spheres then counted for CD133+, CD34+, and Sox2 expression using flowcytometry. Culture plate coated with 1% agarose can be used as an economic and efficient alternative to culture tumor sphere. Using culture plate coated with 1% agarose, the tumor spheres formed in 7 days with similar morphology to non-adhesive culture plate. Tumorsphere had three dimensional – sphere shape that tightly attached, colonized, and overlapped. The tumor sphere colony counts of two plates were statistically have no significant difference (p=0,667). Single cell assay of a tumor sphere shows that it can grow new tumor spheres with similar morphology. The tumor sphere from culture plate coated with 1% agarose express CD133+ and CD34+ as much as 8.78% ± 2.14 and Sox2 as much as 35.30% ± 23.82 whereas tumor sphere from non-adhesive culture plate express CD133+ and CD34+ as much as 62.36% ± 1.06 and Sox2 as much as 98.86% ± 0.56 (p = 0000)

Characteristics of Vacuum Freeze Drying with Utilization of Internal Cooling and Condenser Waste Heat for Sublimation

Vacuum freeze drying is an excellent drying method, but it is very energy-intensive because a relatively long drying time is required. This research investigates the utilization of condenser waste heat for sublimation as a way of accelerating the drying rate. In addition, it also investigates the effect of internal cooling combined with vacuum cooling in the pressure reduction process. Jelly fish tentacles were used as the specimen, with different configurations for condenser heat waste and internal cooling valve opening. The results show that heating with condenser heat waste can accelerate the drying rate up to 0.0035 kg/m2.s. In addition, pre-freezing by internal cooling prevents evaporation until the mass of the specimen is 0.47 g and promotes transition of the specimen into the solid phase

The Helicobacter pylori Genome Project : insights into H. pylori population structure from analysis of a worldwide collection of complete genomes

Helicobacter pylori, a dominant member of the gastric microbiota, shares co-evolutionary history with humans. This has led to the development of genetically distinct H. pylori subpopulations associated with the geographic origin of the host and with differential gastric disease risk. Here, we provide insights into H. pylori population structure as a part of the Helicobacter pylori Genome Project (HpGP), a multi-disciplinary initiative aimed at elucidating H. pylori pathogenesis and identifying new therapeutic targets. We collected 1011 well-characterized clinical strains from 50 countries and generated high-quality genome sequences. We analysed core genome diversity and population structure of the HpGP dataset and 255 worldwide reference genomes to outline the ancestral contribution to Eurasian, African, and American populations. We found evidence of substantial contribution of population hpNorthAsia and subpopulation hspUral in Northern European H. pylori. The genomes of H. pylori isolated from northern and southern Indigenous Americans differed in that bacteria isolated in northern Indigenous communities were more similar to North Asian H. pylori while the southern had higher relatedness to hpEastAsia. Notably, we also found a highly clonal yet geographically dispersed North American subpopulation, which is negative for the cag pathogenicity island, and present in 7% of sequenced US genomes. We expect the HpGP dataset and the corresponding strains to become a major asset for H. pylori genomics

Rancang Bangun dan Analisis Mesin Pengupas Kulit Kacang Tanah Tipe Silinder Horizontal

Proses pemisahan biji dan kulit kacang tanah dapat dilakukan secara tradisional atau menggunakan mesin. Pengupasan kacang tanah secara tradisional dilakukan dengan menggunakan tangan (tanpa alat bantu) atau tongkat. Pengupasan kacang secara tradisional ini tanah dengan menggunakan tangan membutuhkan banyak tenaga dan waktu walaupun hasil pengupasan sangat bagus. Sedangkan pengupasan kacang tanah dengan menggunakan tongkat membuat kualitas kacang tanah hasil kupasan buruk dengan kapasitas kupasan kacang tanah yang juga kecil. Penelitian ini bertujuan membuat mesin pengupas kulit kacang tanah untuk skala industri rumah tangga dan melakukan analisis kinerja serta analisis ekonomi. Metode penelitian dimulai dari identifikasi masalah, penyempurnaan ide rancangan, dilakukan pembuatan alat, uji fungsional, uji kinerja dan terakhir dilakukan analisis ekonomi. Hasil uji kinerja mesin pengupas kulit kacang tanah tipe silinder horizontal diperoleh kapasitas alat 15,22 kg/jam, persentase kacang tidak terkupas 50%, rendemen 33,5%, dan persentase kerusakan hasil 2,15%. Hasil analisis ekonomi teknik diperoleh biaya tetap Rp. 1.654.853,36/tahun, biaya tidak tetap Rp. 27.648,13/jam, biaya pokok Rp. 1.879,48/kg, dan BEP sebanyak 1.732,03 kg/tahun. Mesin ini sangat cocok untuk skala industri rumah tangga karena mempunyai kapasitas 15,22 kg/jam dengan biaya listrik yang kecil sebesar Rp. 272,91/jam