Judul: Near Infrared Refletance Spectrosocopy (NIRS) Qualitative Detection Based on Fatty Acid Profile of Dairy Milk
Abstrak: Penelitian ini bertujuan membuat model kalibrasi menggunakan Near Infrared Reflectance Spectroscopy (NIRS) dari susu sapi perah dengan waktu pemerahan yang berbeda. Pengambilan sampel dilakukan di peternakan rakyat yang berlokasi di tiga tempat yaitu Pangalengan, Cibungbulang, dan Kebon Pedes Jawa Barat. Komponen sampel susu dianalisis menggunakan lactoscan dan identifikasi profil asam lemaknya menggunakan gas chromatography (GC). Sampel susu dianalisis secara rapid menggunakan NIRS. Hasil analisis komponen susu dan asam lemak diolah secara statistik dengan uji normalitas dan uji-t pada SPSS ver. 25. Hasil berbeda nyata didapatkan ada tiga parameter dari susu pemerahan pagi dan sore (P<0,05) yaitu lemak susu, C8:0 dan C14:1. Hasil analisis pada NIRS menunjukkan susu pemerahan pagi dan sore memiliki spektrum serupa yang ditunjukkan dengan nilai Q-value yang rendah (0.0011231). Analisis secara kualitatif pada NIRS tidak dapat membedakan susu hasil pemerahan pagi dan sore hari. Kata kunci: kualitas susu, NIRS, profil asam lemak, susu, waktu pemerahan., The objective of this study was to create calibration model using Near Infrared Reflectance Spectroscopy (NIRS) from dairy milk with the differences milking time. Milk sampling were collected from three different farms location in Pangalengan, Cibungbulang, and Kebon Pedes West Java. The quality of the milk samples were analyzed using lactoscan and gas chromatography (GC) to identified the FA profiles of milk. Sample also analyzed rapidly using NIRS. The result of analyzed using lactoscan and GC were stastistically tested using normality test and t-test carried out SPSS ver. 25. Analysis on GC and lactoscan it were found three parameters that significantly different (P<0.05) between morning and afternoon milking time, namely milk fat, C8:0 and C14:1. However, the result using NIRS indicate that all parameters have similar spectrum between morning and afternoon milking that marked by low Q-value (0.0011231). It is concluded that NIRS spectrum can not differentiate milk from morning and afternoon milking qualitatively. Keywords: FA profiles, milk, milking time, NIRS, quality of milk.
Keyword: Kualitas susu, NIRS, Profil asam lemak, Susu, Waktu pemerahan

Judul: Pembuatan Model Kalibrasi Sampel Recovery Produk Susu dengan Metode Spektroskopi Inframerah di PT Frisian Flag Indonesia
Abstrak: Milk is a kind of food that has nutritional contents and compositions almost perfect compared to other foods. Manufacture of milk products result by-products called recovery samples. Infrared spectroscopy methods such as Near Infrared Reflectance (NIR) and Fourier Transform Infrared (FTIR) can be used as a secondary method for evaluating quality of dairy products. PT Frisian Flag Indonesia will use infrared spectroscopy methods to analyze quality of recovery samples. FTIRS and NIRS instruments must have a calibration model for recovery sample that includes parameters of composition i.e total solids, fat content, sucrose, and proteins so that can be used to evaluate quality of recovery sample. The purpose of this study was to create a calibration model from recovery samples of dairy products by infrared spectroscopy methods. In general, the development stages of calibration models using NIR and FTIR methods consist of sample preparation, analysis of composition parameters, calibrations modeling, and verification of the models. Sample preparation was canducted by using two variants of A product recovery sample (NIR method) and B product recovery sample (FTIR method). Instrument used for analyzing NIR method is FOSS NIRSystems 5000 and for FTIR method is FOSS MilkoScan FT120. The conventional analysis methods were also used to analyze parameters of composition. Calibration modeling that conducted by software WinISI and models was verificated by t-test. The results of spectrum NIR shows A product recovery sample for variant X and Y have similar spectrums. Model calibration of total solid is the best model in NIR methods (R2 = 0.9998) and FTIR method (R2 = 0.9993). The results of t-test with 5% level of significance shows that the parameters of composition in both calibration models of infrared spectroscopy methods were not significant different (P (two-tail) > 0.05). This results showed that both of calibration models can be used.
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Judul: Closed Knight’s Tour pada Papan Catur Berbentuk Persegi Panjang dengan Ukuran Maksimal 8 × 8
Abstrak: Closed Knight’s Tour merupakan langkah kuda yang mengunjungi setiap kotak pada papan catur tepat satu kali dengan langkah kuda berawal dan berakhir pada kotak yang sama. Graf yang terbentuk dari closed knight’s tour dinotasikan sebagai graf G(m,n), dengan m adalah banyaknya baris dan n adalah banyaknya kolom. Graf tersebut memuat Hamiltonian cycle. Sebuah graf terhubung G adalah graf bipartite jika dan hanya jika graf tersebut tidak memiliki cycle dengan panjang ganjil. Papan catur yang memenuhi syarat cukup untuk memiliki closed knight’s tour adalah papan catur berukuran 5 × 6, 5 × 8, 6 × 6, 6 × 7, 6 × 8, 7 × 8, dan 8 × 8.
Keyword: bipartite, closed knight’s tour, hamiltonian cycle, knight’s tour, teori graf