Judul: Efektivitas beberapa uji pemalsuan madu kapuk
Abstrak: This study was conducted to determine the effectiveness of several adulteration tests for honey. There were many adulteration tests usually done by people to distinguish between pure and artificial honey. This experiment studied several adulteration tests such as ant test, soluble test, turbidity test, foam test, heated test, pull test, sticky test, hexagon test, raw fish test, and iodine test. The artificial honey were divided into three, namely artificial honey with thickener (CMC and gelatin), artificial honey with sugar (sucrose, fructose and glucose), and artificial honey with sugar and thickener (sugar and sago). Chemical analysis such as pH, moisture, HMF (Hidroxymethylfurfural) and sugar content (sucrose, fructose and glucose) were also conducted to support the result of adulteration tests. From all adulteration tests, the most effective test was soluble test with number of effectiveness 83,3%. The other effective tests that can be applied to distinguish between pure honey and artificial honey were raw fish test (60%), turbidity test (52,5%), and heated test (49,2%). Artificial honey with sugar dan thickener (sugar and sago) was the most easily to be detected, and artificial honey with sugar (sucrose, fructose, and glucose) was the most difficult to be detected.
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Judul: Physicochemical Analysis of Kelulut Honey from Various Locations in Indonesia with Various Heating Temperatures
Abstrak: Madu kelulut dikenal sebagai stingless bee honey atau madu Meliponinae. Penelitian bertujuan untuk mengidentifikasi sifat fisikokimia madu Kelulut dari lokasi Serang, Bogor, Bangka, Sumedang, Garut, Klaten, dan Batu Ampar dengan ragam suhu pemanasan. Sifat fisikokimia yang diuji pada penelitain ini meliputi intensitas warna, total padatan terlarut, kadar air, viskositas, kelarutan, hidroksimetilfurfural, keasaman, gula pereduksi, dan sukrosa. pada madu dengan variasi suhu pemanasan yakni suhu ruang (25 °C), 65 °C and 121 °C. Hasil penelitian ini menunjukkan adanya perubahan sifat fisik maupun kimia yang terjadi pada madu diakibatkan pemanasan. Salah satunya adalah nilai gula pereduksi yang menunjukkan penurunan yang konsisten pada kedua ragam suhu pemanasan. Madu Garut pada perlakuan suhu normal memiliki kadar air sebesar 18,5 %b/b, keasaman sebesar 170 ml NaOH/kg, hidroksimetilfurfural sebesar 27,4 mg/kg, gula pereduksi sebesar 70,8 %b/b, dan sukrosa sebesar 1,4 %b/b, sehingga memiliki kesesuaian dan memenuhi Standar Nasional Indonesia. Hasil dari penelitian semua madu mengalami perubahan karakteristik fisik maupun kimia., Kelulut honey is known as stingless bee honey or Meliponinae honey. The study aimed to identify the physicochemical properties of Kelulut honey from Serang, Bogor, Bangka, Sumedang, Garut, Klaten, and Batu Ampar with various heating temperatures. The physicochemical properties tested in this research include colour intensity, total soluble solids, moisture content, viscosity, solubility, hydroxymethylfurfural, acidity, reducing sugar, and sucrose in honey with variations in heating temperature, namely room temperature (25 °C), 65 °C and 121 °C. The results of this study show that there are changes in physical and chemical properties occur in honey due to heating. One of them is the value of Reducing Sugar which shows a consistent decrease in both heating temperature variations. Garut honey in the normal temperature treatment has a moisture content of 18.5 %w/w, the acidity of 170 ml NaOH/kg, hydroxymethylfurfural of 27.4 mg/kg, reducing sugar of 70.8 %w/w, and sucrose of 1.4 %w/w, so it has conformity and meets the Indonesian National Standard. The results of the research all honey experienced changes in physical and chemical characteristics.
Keyword: honey, heating, physicochemistry, stingless bee

Judul: igenvalues and Eigenvectors of Tridiagonal Matrix with Non Constant and Recurrent Diagonal Entries.
Abstrak: Matriks tridiagonal adalah suatu matriks yang mempunyai entri-entri bernilai nol kecuali pada diagonal utama, di bawah diagonal utama (subdiagonal) dan di atas diagonal utama (superdiagonal). Entri pada diagonal utama tidak konstan dan berulang. Setiap entri pada matriks tridiagonal ini adalah bilangan kompleks. Dalam karya ilmiah ini, akan dibuktikan 3 teorema untuk menentukan nilai eigen dengan 2 kasus dan 1 teorema untuk menentukan vektor eigen. Teorema pertama menentukan polinomial karakteristik dari matriks tridiagonal. Polinomial karakteristik dari matriks tridiagonal tersebut digunakan untuk menentukan nilai eigen pada teorema kedua dan ketiga serta menentukan vektor eigen pada teorema keempat
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