Judul: Pengaruh Pemupukan Boron terhadap Kualitas Buah Manggis (Garcinia mangostana L.).
Abstrak: The objective of this research was to study the effect of boron application on fruit quality of mangosteen, especially the scaring and yellow latex incidence (gamboges). The research was conducted at mangosteen orchard Cicantayan Sukabumi, Laboratory Centre for Tropical Horticulture Studies (PKHT) IPB, and Post Harvest Laboratory of Agronomy and Horticulture IPB on November 2011 to April 2012. The research was arranged in Randomized Complete Design with one factor of treatment: Boron dose (B2O3). There were four doses of fertilizer used consisted of : the control with no fertilizer application B2O3, 15, 30, and 45 g B2O3 / plant. The results of this research showed that Boron application have significant effect on gamboges on pericarp of the mangosteen fruit when compared to controls. However, Boron application significantly increase fruit weight and diameter as well as totat soluble solids content, but there is no different effect of doses between 15, 30, and 45 g/ plant. This treatment is also have no effect on other components of the mangosteen fruit qualities such as hardness of fruit, fruit weight and skin thickness, total of titrable acid, and vitamin C in the mangosteen.
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Judul: Pengaruh penyemprotan pupuk boron terhadap kualitas buah manggis (Garcinia mangostana L.)
Abstrak: Manggis merupakan komoditas unggulan buah tropika yang banyak digemari masyarakat baik dalam maupun luar negeri. Buah unggulan Indonesia ini termasuk buah segar yang banyak di ekspor keluar negeri. Akan tetapi volume ekspornya masih rendah bila dibandingkan dengan total produksi yang dihasilkan. Hal tersebut disebabkan adanya pencemaran getah kuning pada manggis, sehingga menyebabkan kualitas buah menurun. Getah kuning merupakan getah alami yang berada di semua bagian pohon manggis kecuali pada akar. Getah tersebut akan keluar mengotori aril (daging) dan kulit buah bila salurannya terganggu. Saluran getah kuning yang terganggu diduga disebabkan oleh kekurangan unsur-unsur hara, perubahan tekanan turgor pada dinding sel, interaksi gangguan fisiologis dan gangguan fisik buah. Salah satu unsur hara yang perlu diperhatikan dalam kejadian getah kuning yaitu boron. Boron merupakan unsur hara mikro esensial yang diperlukan dalam jumlah sedikit pada tanaman. Boron memiliki peran dalam fungsi membran, pembentukan struktur pektin di dinding sel primer, dan sebagai pendukung serapan kalsium. Pemberian boron yang berlebihan akan menyebabkan toksisitas antara lain gangguan perkembangan dinding sel, gangguan metabolik, terhambatnya pembelahan dan pemanjangan sel. Pemberian boron yang tepat diduga akan mengurangi pencemaran getah kuning pada buah manggis. Tujuan dari penelitian ini adalah mempelajari pengaruh penyemprotan pupuk boron dengan berbagai konsentrasi pada buah terhadap kualitas buah manggis. Penelitian ini dilaksanakan pada Januari sampai April 2012, di kebun petani manggis Desa Hegarmanah, Kabupaten Sukabumi. Analisis sampel tanah dan daun pada tanaman dilakukan di Laboratorium Tanah Departemen Ilmu Tanah dan Sumberdaya Lahan IPB. Pengamatan uji kualitas buah dilakukan di Laboratorium Pusat Kajian Hortikultura Tropika Baranangsiang Bogor. ...
Keyword: Boron, Concentration, Mangosteen, Fruit Quality

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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