Judul: Kajian Pola Pencampuran Reaktan di dalam Static Mixing Reactor untuk Produksi Biodiesel
Abstrak: Biodiesel is a diesel fuel substitute materials from the transesterification reaction, ie mixing vegetable oils or animal fats with methanol. Transesterification reaction can be carried out in the static mixing reactor (SMR) to improve mixing. Simulation method with Computational Fluid Dynamics can be used to determine the mixing patterns and relation to the rate of biodiesel production in the SMR. Simulations performed using the stirrer element with twist angle 180°, 120° and 240°. Results of this study indicate that a decline in velocity when the flow through the mixer element, the larger twist angle of the mixer elements produced flow velocity which is uniform, and longer reaction rate where a molecular viscosity values are uniform. Based on the flow velocity, reaction rates and molecular viscosity is known that the mixer element with twist angle of 240° have a better pattern mixing than element with twist angle 180° and 120°.
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Judul: Simulation of Reactant Mixing in Biodiesel Production using Static Mixing Reactor
Abstrak: Penggunaan pengaduk statik untuk produksi biodiesel mampu memberikan hasil yang baik, serta dapat mengurangi penggunaan katalis. Pengaduk statik dapat meningkatkan ketercampuran minyak dan metanol sehingga FAME yang dihasilkan pada modul terakhir meningkat dan diharapkan dapat mencapai tingkat konversi yang diharapkan dengan penggunaan katalis yang lebih sedikit. Kajian lebih mendalam mengenai tingkat ketercampuran serta kaitannya dengan efektivitas reaksi transesterifikasi yang terjadi perlu dilakukan untuk mendapatkan parameter penting dalam perbaikan proses maupun rancangan reaktor. Penelitian ini bertujuan untuk melihat pengaruh laju aliran massa terhadap ketercampuran minyak dan metanol di dalam reaktor berpengaduk statik tipe kontinu dengan menggunakan metode computational fluid dynamics (CFD). Simulasi dilakukan dengan empat skenario laju aliran massa pada kisaran 0.17-0.25 kg s-1 untuk minyak dan 0.021-0.030 kg s-1 untuk metanol. Hasil simulasi menunjukkan bahwa keberadaan elemen pengaduk di dalam pipa reaktor berpengaduk statik memberikan pengaruh terhadap pergerakan molekul tidak hanya ke arah arus utama (arah aksial) tetapi juga terjadi gerakan acak ke arah sumbu y dan z, serta gerakan rotasi. Terjadinya gerakan tersebut mempengaruhi ketercampuran fluida yang dapat diukur dengan nilai vortisitas. Berdasarkan empat skenario laju aliran massa tersebut, ketercampuran molekul dan vortisitas aliran yang seragam dapat dicapai serta dipertahankan dengan menambah jumlah elemen pengaduk sambil memberi waktu tinggal yang lebih lama untuk mencapai reaksi dengan tingkat konversi yang diharapkan. Konsentrasi FAME tertinggi diperoleh pada laju aliran minyak 0.17 kg s-1 dan metanol 0.02 kg s-1, yaitu 78.86%., Application of static mixer is expected to enhance yield of biodiesel production and reduce catalyst requirement. Static mixer could increase the mixing effectiveness of oil and methanol, so that FAME yielded at the reactor would increase and could reach the desired level of conversion with lower catalyst requirement. A more in-depth study of the mixing and its relation to the effectiveness of transesterification reactions is indispensable to obtain important parameters which is necessary in process improvement and reactor design. The objective of this study was to examine the effect of mass flow rate on mixing of oil and methanol in a continuous type reactor using computational fluid dynamics (CFD). Simulation was conducted using four scenarios of mass flow rate in the range of 0.17-0.25 kg s-1 for oil and 0.02-0.03 kg s-1 for methanol. It was observed that the static mixer elements has an effect on the movement of the molecule, which indicates that the flow is not only moved in the mainstream (axial direction) but also moves toward the y-axis and the z-axis randomly as well as rotational motion. The occurance of motion affects the mixing of the fluid which can be quantified by vorticity value. Based on the four scenarios of mass flow rate, molecular mixing and vorticity’s uniformity can be achieved and maintained by increasing the amount of mixer element, while giving longer residence times to reach the desired level of conversion. The highest FAME concentration was obtained at the oil flow rate of 0.17 kg s-1 and methanol 0.02 kg s-1, which is 78.86%.
Keyword: Catalyst, FAME, Biodiesel, Transesterifikasi, Pengaduk statik, CFD, Vortisitas

Judul: Prevalence of Bird Lice on Rock Pigeon (Columba livia) in 99Wonderland Park, Selangor, Malaysia
Abstrak: Rock Pigeon (Columba livia) have coexisted with humans for thousands of years and are used for various purposes such as food and in sports. Rock pigeons may have the potential to be infested with a wide range of ectoparasites, which can have a significant impact on their life cycle. This study aims to measure the prevalence of Columba livia with bird lice in 99Wonderland Park, Selangor, Malaysia in the year 2020 and to ascertain the impact of bird lice on the health of these infested birds. Data were collected from clinical records for the month of January to December in the year 2020 from 99Wonderland Park, Selangor, Malaysia. Lice were identified in 42 of the 80 Rock pigeons examined so, the overall prevalence of lice infestations was 52.5%. The prevalence of ectoparasites was found to be higher in young Rock pigeons (60.4%) as compared to adult Rock pigeons (37.4%). Columbicola columbae (wing lice) and Colpocephalum turbinatum (body lice) are two species of lice that have been detected. Body lice were more prevalent in young Columba livia birds at 47.6% whereas wing lice were more prevalent in adult Columba livia birds at 16.7%. Most of the lice were found in the thorax and abdomen area followed by the head and neck area., Merpati Batu (Columba livia) telah hidup berdampingan dengan manusia selama ribuan tahun dan digunakan untuk berbagai keperluan seperti makanan dan olahraga. Merpati batu dapat terinfestasi dengan berbagai ektoparasit, yang dapat berdampak signifikan pada siklus hidup mereka. Penelitian ini bertujuan untuk mengetahui prevalensi Columba livia dengan kutu burung di 99 Wonderland Park, Selangor, Malaysia pada tahun 2020 dan untuk memastikan dampaknya terhadap kesehatan burung yang terinfestasi. Data dikumpulkan dari catatan klinis dari bulan Januari hingga Desember tahun 2020 dari 99Wonderland Park, Selangor, Malaysia. Kutu diidentifikasi pada 42 dari 80 merpati batu yang diperiksa sehingga, prevalensi keseluruhan infestasi kutu adalah 52,5%. Prevalensi ektoparasit ditemukan lebih tinggi pada merpati batu muda (60,4%) dibandingkan dengan merpati batu dewasa (37,4%). Columbicola columbae (kutu sayap) dan Colpocephalum turbinatum (kutu badan) adalah dua spesies kutu yang telah ditemukan. Kutu badan lebih banyak ditemukan pada burung Columba livia muda sebesar 47,6% sedangkan kutu sayap lebih banyak ditemukan pada burung Columba livia dewasa sebesar 16,7%. Sebagian besar kutu ditemukan di daerah dada dan abdomen diikuti daerah kepala dan leher.
Keyword: Columba livia, prevalence, ectoparasite, wing lice, body lice, Columba livia, prevalensi, ektoparasit, kutu sayap, kutu badan