Judul: Chemical Characteristics of Gemor Bark (Alseodaphne spp.)
Abstrak: Sifat kimia merupakan salah satu sifat dasar yang berpengaruh pada pemanfaatan biomasa berdasarkan komponennya seperti untup pulp, energi, farmasi, dan bahan kimia lainnya. Untuk meningkatkan nilai manfaat kulit gemor dapat dilakukan melalui pengembangan produk berdasarkan komponen kimianya, sehingga diperlukan informasi tentang kadar komponen kimia dan sifat kimianya. Penelitian ini bertujuan untuk menguji kadar komponen kimia, proksimat, dan fitokimia kulit kayu gemor. Sampel kulit gemor berasal dari Kabupaten Katingan, Kalimantan Tengah. Penentuan kadar komponen kimia mengacu pada TAPPI dan metode Browning, analisis proksimat mengacu pada standar ASTM, dan analisis fitokimia mengacu pada metode Harbone. Kadar komponen kimia kulit gemor terdiri atas holoselulosa 63,59%, α-selulosa 46,19%, hemiselulosa 17,39%, lignin 43,56%, kadar abu 1,32%, kelarutan dalam air panas 19,49%, kelarutan dalam air dingin 18,21%, kelarutan dalam NaOH 1% 47,65%, dan ethanol-benzena 27,66%. Kulit gemor memiliki zat terbang 78,04% dan karbon terikat 20,64%. Analisis fitokimia mengkonfirmasi adanya senyawa flavanoid, phenolic, alkaloid, tannin, saponin, triterpenoid, steroid dalam kulit kayu gemor. Kulit gemor berpotensi sebagai bahan baku bioenergi karena mengandung kadar lignin dan zat ekstraktif yang tinggi., Chemical properties is one of the basic properties that affect the utilization of biomass based on its components such as for pulp, energy, pharmaceuticals, and other chemicals. To increase the value of the benefits of gemor bark , it can be done through product development based on its chemical components, so information about the content of chemical components is needed. This study aims to examine the content of chemical components, proximate, and phytochemical gemor bark. Gemor bark samples were taken from Katinga, Central Kalimantan. Determination of chemical component content refers to TAPPI standard and Browning method, proximate analysis refers to ASTM standard, and phytochemical analysis refers to the Harbone method. The chemical component content of gemor bark consists of holocellulose 63.59%, α-cellulose 46.19%, hemicellulose 17.39%, lignin 43.56%, ash content 1.32%, solubility in hot water 19.49%, solubility in cold water 18.21%, solubility in 1% NaOH 47.65%, and ethanol-benzene 27.66%. Gemor bark has 78.04% volatile matter and 20.64% fixed carbon. Phytochemical analysis confirmed the presence of flavonoid, phenolic, alkaloid, tannin, saponin, triterpenoid, steroid compounds in gemor bark. Gemor bark has the potential as a bioenergy raw material because it contains high content of lignin and extractive substances.
Keyword: gemor bark, chemical components, phytochemicals, biomass, pulp

Judul: Sifat Kimia dan Proksimat Biomassa Lima Jenis Kulit Kayu.
Abstrak: Karakterisasi sifat kimia kulit kayu sebagai bahan baku energi biomassa dilakukan untuk eksplorasi sumber energi alternatif terbarukan yang berpotensi menjadi substitusi energi fosil. Penelitian ini bertujuan untuk menguji kadar komponen kimia lima jenis kulit kayu dan pengaruhnya terhadap mutu biomassa sebagai bahan energi melalui uji proksimat. Sampel yang digunakan yaitu kulit kayu mindi, sengon, pinus, jati, dan mangium. Penentuan kadar komponen kimia kayu mengacu pada standar TAPPI dan Browning (1967). Analisis proksimat mengacu pada standar ASTM dan SNI. Biomassa kulit kayu memiliki nilai kalor tinggi berkisar 3665-4199 kkal/kg. Nilai kalor tersebut berkorelasi dengan kadar karbon terikat yang dipengaruhi positif oleh kadar lignin. Polisakarida kayu yang dinyatakan dengan holoselulosa, dan kadar abu cenderung berpengaruh negatif terhadap nilai kalor. Biomassa kulit kayu berpotensi sebagai bahan baku energi biomassa dan sebagai fortifikasi untuk meningkatkan mutu biomassa berkalor rendah.
Keyword: analisis proksimat, bioenergi, biomassa, komponen kimia, kulit kayu

Judul: A Continuous Vaccination Strategy in the SVIR Epidemic Model
Abstrak: Vaccination is conducted to minimize the spread of a disease. The vaccination is usually done several times within a fixed time interval. In the SVIR model, it is assumed that individuals do not get immediate immunity following a vaccination program. So according to process of vaccination on SVIR model, there are two strategies, i.e. the continuous vaccination strategy (CVS) and the pulse vaccination strategy (PVS). In this study, only the CVS strategy in epidemic model SVIR is considered. Results of the study indicate that dynamics of the CVS system depends on the basic reproductive number. If the basic reproductive number is less than one, then the disease-free fixed point is asymptotically stable. It means that the disease will eventually disappear from the population. Conversely, if the basic reproductive number is greater than one, then the endemic fixed point is asymptotically stable, which means that the disease will remain exist in the population. Simulation result shows that the vaccination would minimize the spread of disease by reducing the basic reproductive number. If the time for the vaccinated recipients to obtain the immunity, as well as a possibility of vaccinated recipients to be infected are neglected, then the disease will be eradicated. This condition is called an over-evaluating effect of vaccination.
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