scholarly journals Keanekaragaman tanaman Garcinia di Kebun Raya Bogor, Indonesia

2021 ◽  
Vol 4 (1) ◽  
pp. 139-150
Author(s):  
Anis Masdar ◽  
Gia Laras Pangestu ◽  
Balqis Wahyu Utami ◽  
Yohana Olivia Stefany ◽  
Rosa Amalia ◽  
...  

Garcinia adalah nama marga tumbuh-tumbuhan dari suku Clusiaceae. Salah satu spesies tanaman Garcinia di Indonesia merupakan tanaman komoditas dan dapat dimakan yakni Garcinia mangostana, biasa dikenal juga dengan sebutan tanaman buah manggis. Tanaman ini memiliki beragam manfaat dari bagian tanamannya, seperti daun serta buah. Beragamnya spesies tanaman Garcinia mengartikan bahwa semakin banyak manfaat yang bisa diperoleh. Kebun Raya Bogor merupakan lahan pelestarian di bidang ex-situ yang memiliki peran alih lahan konservasi serta bidang pendidikan dan penelitian, dalam hal ini terkhusus dalam spesies tanaman Garcinia. Penelitian ini bertujuan untuk mengetahui keanekaragaman serta dominansi tanaman Garcinia yang ada di Kebun Raya Bogor. Penelitian ini dilaksanakan pada 25 November 2020. Pengambilan data dilakukan dengan menghitug jumlah tanaman serta mengindentifikasi spesies tanaman Garcinia. Metode yang digunakan adalah non destruktif dengan teknik quadrat sampling. Hasil penelitian menunjukkan bahwa terdapat 12 spesies tanaman Garcinia terindentifikasi dengan total jumlah individu sebanyak 17. Nilai indeks keanekaragaman (H’) tanaman Garcinia adalah 2,316, hasil ini menunjukkan bahwa keanekaragaman tanaman Garcinia, produktivitas serta kompleksitas ekosistemnya dalam kategori cukup. Sedangkan nilai indeks dominansi (C) tertinggi adalah tanaman Garcinia syzigifolia dengan angka 0,05536, hasil ini menunjukkan bahwa nilai indeks dominansi yang didapatkan berada pada kategori dominansi rendah dan pola dominansi spesies tanaman Garcinia adalah menyebar di Kawasan Kebun Raya Bogor.

Author(s):  
D. Loretto ◽  
J. M. Gibson ◽  
S. M. Yalisove ◽  
R. T. Tung

The cobalt disilicide/silicon system has potential applications as a metal-base and as a permeable-base transistor. Although thin, low defect density, films of CoSi2 on Si(111) have been successfully grown, there are reasons to believe that Si(100)/CoSi2 may be better suited to the transmission of electrons at the silicon/silicide interface than Si(111)/CoSi2. A TEM study of the formation of CoSi2 on Si(100) is therefore being conducted. We have previously reported TEM observations on Si(111)/CoSi2 grown both in situ, in an ultra high vacuum (UHV) TEM and ex situ, in a conventional Molecular Beam Epitaxy system.The procedures used for the MBE growth have been described elsewhere. In situ experiments were performed in a JEOL 200CX electron microscope, extensively modified to give a vacuum of better than 10-9 T in the specimen region and the capacity to do in situ sample heating and deposition. Cobalt was deposited onto clean Si(100) samples by thermal evaporation from cobalt-coated Ta filaments.


Author(s):  
K. Barmak

Generally, processing of thin films involves several annealing steps in addition to the deposition step. During the annealing steps, diffusion, transformations and reactions take place. In this paper, examples of the use of TEM and AEM for ex situ and in situ studies of reactions and phase transformations in thin films will be presented.The ex situ studies were carried out on Nb/Al multilayer thin films annealed to different stages of reaction. Figure 1 shows a multilayer with dNb = 383 and dAl = 117 nm annealed at 750°C for 4 hours. As can be seen in the micrograph, there are four phases, Nb/Nb3-xAl/Nb2-xAl/NbAl3, present in the film at this stage of the reaction. The composition of each of the four regions marked 1-4 was obtained by EDX analysis. The absolute concentration in each region could not be determined due to the lack of thickness and geometry parameters that were required to make the necessary absorption and fluorescence corrections.


Author(s):  
D. Loretto ◽  
J. M. Gibson ◽  
S. M. Yalisove

The silicides CoSi2 and NiSi2 are both metallic with the fee flourite structure and lattice constants which are close to silicon (1.2% and 0.6% smaller at room temperature respectively) Consequently epitaxial cobalt and nickel disilicide can be grown on silicon. If these layers are formed by ultra high vacuum (UHV) deposition (also known as molecular beam epitaxy or MBE) their thickness can be controlled to within a few monolayers. Such ultrathin metal/silicon systems have many potential applications: for example electronic devices based on ballistic transport. They also provide a model system to study the properties of heterointerfaces. In this work we will discuss results obtained using in situ and ex situ transmission electron microscopy (TEM).In situ TEM is suited to the study of MBE growth for several reasons. It offers high spatial resolution and the ability to penetrate many monolayers of material. This is in contrast to the techniques which are usually employed for in situ measurements in MBE, for example low energy electron diffraction (LEED) and reflection high energy electron diffraction (RHEED), which are both sensitive to only a few monolayers at the surface.


Author(s):  
M. E. Twigg ◽  
B. R. Bennett ◽  
J. R. Waterman ◽  
J. L. Davis ◽  
B. V. Shanabrook ◽  
...  

Recently, the GaSb/InAs superlattice system has received renewed attention. The interest stems from a model demonstrating that short period Ga1-xInxSb/InAs superlattices will have both a band gap less than 100 meV and high optical absorption coefficients, principal requirements for infrared detector applications. Because this superlattice system contains two species of cations and anions, it is possible to prepare either InSb-like or GaAs-like interfaces. As such, the system presents a unique opportunity to examine interfacial properties.We used molecular beam epitaxy (MBE) to prepare an extensive set of GaSb/InAs superlattices grown on an GaSb buffer, which, in turn had been grown on a (100) GaAs substrate. Through appropriate shutter sequences, the interfaces were directed to assume either an InSb-like or GaAs-like character. These superlattices were then studied with a variety of ex-situ probes such as x-ray diffraction and Raman spectroscopy. These probes confirmed that, indeed, predominantly InSb-like and GaAs-like interfaces had been achieved.


Planta Medica ◽  
2009 ◽  
Vol 75 (09) ◽  
Author(s):  
W Pothitirat ◽  
P Pithayanukul ◽  
MT Chomnawang ◽  
W Gritsanapan

Planta Medica ◽  
2009 ◽  
Vol 75 (09) ◽  
Author(s):  
AA El-Gamal ◽  
OA Basudan ◽  
AJ Al-Rehaily ◽  
MH Assaf ◽  
FM Abd El Halim ◽  
...  

Planta Medica ◽  
2012 ◽  
Vol 78 (11) ◽  
Author(s):  
JS Sung ◽  
CW Jeong ◽  
YY Lee ◽  
HS Lee ◽  
YA Jeon ◽  
...  

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