Judul: Dinamika internal atom dalam medan laser dan medan magnet eksternal
Abstrak: Prinsip utama laser cooling adalah menurunkan suhu suatu partikel dengan cara membatasi pergerakannya. Ketika ruang gerak suatu partikel dibatasi, maka sifat-sifat dari partikel itu akan lebih mudah diamati. Diawali dari permodelan atom Rubidium dua level energi yang terdegenerasi akibat medan magnet menjadi atom tiga level energi. Atom tersebut berinteraksi dengan laser yang memiliki frekuensi mendekati nilai frekuensi resonansi atom, dan terjadi transfer momentum antara keduanya. Dalam proses transfer momentum yang melibatkan proses absorpsi dan emisi spektrum laser oleh atom, dapat terjadi pengurangan kelajuan atom. Pada suhu ruang, sebuah atom dapat memiliki kelajuan hingga 300m/s. Namun pada akhir proses laser cooling, kelajuannya dapat berkurang hingga mendekati nol, dengan suhu berkisar pada orde mK. Pengurangan kelajuan akibat gaya hamburan dan gaya dipol yang dialami atom dapat mempengaruhi kondisi internalnya. Hal ini ditunjukkan dalam persamaan matriks densitas yang menggambarkan besar populasi elektron pada tiap level. Gaya dipol minimum dan gaya hamburan maksimum didapat pada nilai detuning sekitar nol.
Keyword: detuning, dipole force, electron population, laser cooling, scattering force

Judul: Dinamika Internal dan Gaya Radiasi pada Molekul Diatomik akibat Interaksi dengan Sinar Laser
Abstrak: Laser cooling of molecules is difficult to implement because of the complex internal structure. Ultracold molecules could potentially be used for a variety of applications and simulations. In this study simulated laser cooling by doppler cooling method on a molecule is described with three energy levels. Changes in the internal dynamics of the molecule and the radiation force examined with variations in the rate of spontaneous emission A2. Optimum radiation force can be achieved when the ratio of the spontaneous emission rate of a given A2 ≥ A1. This is consistent with the internal dynamics which discusses the distribution of the electron population towards stability faster and radiation force obtained with a large order. In theory the emission rate comparison A2 to A1 is 0.52412. This condition is at A2 < A1, it means that the molecule is more difficult cooled because the internal dynamics require a longer time to reach the level of stability and the resulting radiation force is smaller. Given strong laser field affects the frequency of the electrons in the molecule to transition to a certain energy level. For radiation force, the dipole force would be worth a minimum and a maximum value when the scattering force detuning at zero. Radiation force can reduce the effects of thermal motion of molecules in the molecular cooling processes, so it can be used in laser cooling.
Keyword: population ., scattering, emission, dipole, diatomic

Judul: Lejeuneaceae Subfamily Ptychanthoideae (Hepaticae) in  West Java
Abstrak: Subfamily Ptychanthoideae of the family Lejeuneaceae (Hepaticae) in West Java is still poorly known. Publications on this subfamily are out of dated and written in the 19th or early of 20th century. The last taxonomic treatment of Ptychanthoideae of West Java was in 1933, many species names have changed since then. Studies on Ptychanthoideae of West Java are urgently needed. Studies on the Ptychanthoideae were based on the specimens collected from West Java. A total number of 361 of specimens deposited in the Herbarium Bogoriense (BO), Herbarium Biotrop (BIOT), Gottingen Herbarium (GOET) and Bangi Herbarium (UKMB) were examined, those are old and several recent specimens collected in West Java. Recent collections were made from Telaga Warna, Ciater, Gunung Halimun Salak National Park, Cibodas Botanical Garden, Bodogol Education Center and Conservation (Gunung Gede Pangrango National Park), University of Indonesia Campus Depok, including several collections from Banten Province. Twenty four species of Lejeuneaceae subfamily Ptychanthoideae are known from West Java, belonging to 8 genera namely Acrolejeunea (Spruce) Schiffn. (2 species), Archilejeunea (Spruce) Schiffn. (1 species), Lopholejeunea (Spruce) Schiffn. (10 species), Mastigolejeunea (Spruce) Schiffn. (3 species), Ptychanthus Nees (1 species), Schiffneriolejeunea Verd. (1 species), Spruceanthus Verd. (2 species) and Thysananthus Lindenb. (4 species). Two new records of Ptychanthoideae: Mastigolejeunea indica Steph. and Thysananthus minor Verdoorn are reported for Java. A determination key to the species is presented including their descriptions and illustrations.
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