Judul: Anatomi saluran pencernaan rayap bagian tengah dan belakang pada rayap Macrotermes gilvus
Abstrak: Termites are social insects that live in colonies. Termite colony consists of three castes, soldiers caste, worker, and reproductives. This study used ground termites of worker caste Macrotermes gilvus because there is no data on the digestive tract of this termites yet. The aim of this study was to examine the worker midgut and hindgut of M. gilvus. Observations in the digestive tract of termites using parafin embedding method. This study observed enteric valve in the middle of midgut and hindgut. The enteric valve show four folded into the lumen forming a valve. Midgut of M. gilvus consisted of epithlial cells, muscle cells and lumen in the middle. There is no gastric caecum found in termites.
Keyword: Bogor Agricultural University (IPB), gastric caecum, enteric valve, alimentary canal, Ground termites

Judul: Struktur Dan Anatomi Saluran Pencernaan  Rayap Kasta Prajurit Neotermes Bosei
Abstrak: Termites are social insects, that consist of reproductives (drone and queen) and nonreproductives (soldiers and workers) caste. Reproductives, soldiers, and nymphs obtain their food from the workers through trophallaxis in term of stomodeal and proctodeal food. Those kind of food had been digested by the workers. Hence, one can assume that there are differences on termite alimentary canal for each caste. The aim of this study is to examine the soldier’s alimentary canal of Neotermes bosei. Observations and measurements were carried out for the alimentary canal. Those are histology of the gut, the length, perimeter, and area of each canal region. The total length of the alimentary canal from crop to anus is 13.01±1.19 mm, which is divided into 13, 29, and 58% for foregut, midgut, and hindgut, respectively. Every region of the alimentary canal has different characteristics. Epithelium of the alimentary canal are varies from columnar to transtitional. Ventriculus has regenarative crypts. Oesophagus, crop, proventriculus, and rectum have thick muscular tissue. Proventriculus has thick intima. There is no gastric caeca at the midgut. Area with the largest outer perimeter value is the paunch. There are variations in outer and inner perimeter of the alimentary canal. There are several differences between soldiers and workers alimentary canal, such as muscular tissue thicknest, cells structure and their parameters.
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Judul: The Effect of Ni Doped Level on MoS2 as Anode of Natrium Ion Batteries (NIB) on Adsorption and Diffusivity of Na Ions
Abstrak: Perkembangan teknologi elektronik dan kendaraan listrik menuntut ketersediaan baterai isi ulang dengan kapasitas dan ukuran yang besar. Hal ini menyebabkan semakin meningkatnya kebutuhan litium. Li ketersediaannya akan habis dan harganya akan melonjak tinggi. Natrium menjadi solusi karena karakteristiknya menyerupai Li, murah dan ketersediaannya melimpah. Namun, jari-jari kation Na lebih besar sehingga diperlukan modifikasi komponen baterai Na. Studi eksperimental sebelumnya menunjukkan bahwa monolayer MoS2 terdoping menghasilkan kinerja elektrokimia yang ditingkatkan dan kapasitas baterainya lebih tinggi dibandingkan dengan monolayer MoS2 murni. Nikel ditambahkan pada penelitian ini dengan cara doping karena ketersediaan Ni sangat melimpah. Melalui perhitungan DFT, penulis menyelidiki perilaku adsorpsi dan difusi ion Na pada MoS2 murni dan MoS2 terdoping Ni (dengan kadar 0%, 25%, 50% dan 100%). Pengaruh doping Ni pada MoS2 memiliki kelebihan dan kekurangan. Luas permukaan struktur sistem MoS2 terdoping Ni lebih kecil, sifat konduktivitas struktur sistem terdoping menjadi lebih baik, transfer muatan dari permukaan terhadap Na lebih besar, kapasitas penyimpanan baterai meningkat, ion Na teradsorpsi lebih baik karena energinya lebih negatif, namun, atom Na tidak terdifusi dengan baik karena energi aktivasi yang besar sehingga menyebabkan atom Na sulit untuk bergerak.
Keyword: adsorption, diffusion, DFT, Nickel, Sodium