Judul: Kendali Mutu Daun Sambiloto (Andrographis paniculata) Menggunakan Pengolahan Citra dan Teknik Pengenalan Pola secara Kemometrik
Abstrak: Quality of medical plants affects the quality of medicine products. To keep the quality and safety of medicines analysis on quality control is needed. This work aims to use the spectral imaging as a method to quality control of sambiloto leaves with various qualities based on age of plant and combined with pattern recognition techniques (PCA and PLSDA). Thin layer chromatography analysis showed different quality of active compounds in sambiloto at age 1, 2, and 3 months. The best standard model and polynomial using Wiener estimation was 97 colours and 46 herbal images and polynomial of order 2. Root mean square error (RMSE) and goodness of fit coefficient values were of 15.21% and 0.8079, respectively. PCA model gave PC1 98% and PC2 1%. PLSDA analysis gave 3 models, namely 1 month (R2 calibration= 0.8640, R2 prediction= 0.8514, RMSE of calibration (RMSEC)= 0.1693, RMSE of prediction (RMSEP)= 0.1821), 2 month (R2 calibration= 0.7570, R2 prediction= 0.7092, RMSEC= 0.2429, RMSEP= 0.2612), and 3 month (R2 calibration= 0.8167, R2 prediction= 0.7958, RMSEC= 0.1929, RMSEP= 0.2070).
Keyword: spectral imaging, sambiloto, quality control, PLSDA, PCA

Judul: Classification of Andrographis paniculata by cultivation ages using FTIR and LC-MS/MS in Combination with Chemometric
Abstrak: Sambiloto (Andrographis paniculata) merupakan tanaman yang memiliki banyak khasiat seperti antibakteri, antimalaria, antipretik, anti-inflamasi, dan antidiabetes. Khasiatnya berasal dari aktivitas biologis didalamnya yang mengandung senyawa aktif dengan komposisi dan konsentrasi tertentu. Komposisi dan konsentrasi senyawa aktif dalam suatu tanaman dapat dipengaruhi oleh beberapa faktor seperti tempat tumbuh, umur tanam, dan proses pascapanen. Perbedaan level aktivitas biologis tersebut mempengaruhi kualitas tanaman tersebut. Suatu kendali mutu diperlukan agar khasiat dan kualitas sambiloto dapat terjaga. Metode kendali mutu tersebut dapat dilakukan melalui pendekatan metabolomik. Pendekatan metabolomik dapat menampilkan sidik jari dan profil metabolit pada tanaman dengan berbagai keadaan. Pendekatan metabolomik yang umum digunakan adalah metode kromatografi dan spektroskopi namun kedua metode tersebut menghasilkan data yang besar dan sangat kompleks sehingga sulit diinterpretasi. Oleh karena itu, data tersebut diolah menggunakan metode kemometrik. Penelitian ini bertujuan mengklasifikasi herba sambiloto berdasarkan umur tanam menggunakan FTIR dan kromatografi cair-spektrometer massa (KC-SM) dikombinasi dengan kemometrik. Sampel herba sambiloto yang didapatkan memiliki perbedaan umur tanam 2, 3 dan 4 bulan yang berasal dari kebun percobaan Pusat Studi Biofarmaka Tropika, Bogor, Indonesia. Herba sambiloto dipreparasi menggunakan teknik quenching dan setelahnya diekstraksi menggunakan etanol. Larutan ekstrak kemudian dijadikan esktrak kering menggunakan penguap putar dan freeze dryer. Ekstrak tersebut dihitung persentase rendemennya. Setelahnya, dilakukan analisis menggunakan FTIR dan KC-SM sehingga diperoleh data spektrum dan identifikasi senyawa aktif yang dapat diolah menggunakan principal component analysis (PCA). Hasil spektrum FTIR dan KC-SM memberikan pola yang sama dengan perbedaan terdapat pada intensitas puncaknya. Hal ini menunjukkan masing-masing sampel memiliki senyawa yang sama tetapi terdapat perbedaan konsentrasi didalamnya. Identifikasi senyawa aktif dilakukan dengan menggunakan fragmentasi dan konfirmasi perbandingan literatur dari herba sambiloto. Sebanyak 21 senyawa dapat teridentifikasi yang terdiri atas golongan asam fenolat, diterpena lakton dan flavonoid. Hasil spektrum FTIR dan senyawa teridentifikasi aktif herba sambiloto dapat dikelompokkan berdasarkan umur tanamnya menggunakan teknik PCA. Selain itu, biplot dapat memberikan informasi variabel yang berpengaruh pada skor plot. Bilangan gelombang 1800-800 cm-1 memberikan pengaruh yang cukup besar pada skor plot FTIR sedangkan pada data KC-SM terdapat 4 senyawa yang berpengaruh pada skor plot., Andrographis paniculate has many efficacies as antibacterial, antimalarials, antipyretics, anti-inflammatory, and antidiabetic. The efficacy is related to a biological activity that has active compounds with particular composition and concentration. The composition and concentration of the active compounds are influenced by several factors such as growing places, cultivation ages dan post-harvest processes. The difference level of biological activity affects the quality of the plant. Therefore, quality control is needed to preserve the efficacy and quality of A. paniculata. The metabolomics approach is a method that can be used for quality control of A. paniculata. Metabolomics approaches can represent metabolite profiles and fingerprints of plants in many conditions. The commonly used metabolomic approaches are the chromatography and spectroscopic methods, but both produce large and complex data that are difficult to interpret. Hence, The data are processed using chemometrics. This study aims to classify A. paniculate based on cultivation ages using FTIR and LC-MS combined chemometrics. A. paniculate samples were collected from the Tropical Biopharmaca Research Center Garden, Bogor, Indonesia, with different cultivation ages by 2, 3, and 4 months.
Keyword: A. paniculata, chemometrics, FTIR, LC-MS, PCA

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.
Keyword: