Judul: Karakteristik Fisik Sabun Padat Berbahan Dasar Tallow dengan Penambahan Susu atau Krim
Abstrak: Animal fat generally have low economic value and less utilization. Animal fat can be processed into tallow through rendering process to produce a raw material in soap making. The purpose of this research was to analyze physical properties of soap by using tallow with milk or cream addition as raw material. The observed variables in this research were water content, hardness, pH, and foaming height. The randomized complete design with 4 treatments and 1 control was used as experimental design. Data were analyzed by analysis of variance (ANOVA). Kruskal Wallis test were used for nonparametric data. The results showed that water content of cream tallow soap and milk tallow soap had significant difference (P<0.05) with control soap. Hardness and foaming height of soap between treatments soaps and control soap had no significant difference. The value of pH of milk tallow soap had significant difference (P<0.05) with cream tallow soap and control. The organoleptic test results showed that cream tallow soap had significant difference (P<0.05) in colour with milk tallow soap. The cream tallow soap had no significant difference of favour with milk tallow soap. There was no significant difference on foaming ability between cream tallow soap and milk tallow soap.
Keyword: tallow, soap, physical properties

Judul: Pengaruh Penambahan Ekstrak Tea Tree dan Peppermint pada Kualitas Sabun Padat Berbahan Dasar Tallow
Abstrak: Tallow merupakan minyak yang diperoleh dari hasil ektraksi lemak abdomen sapi. Tallow dari lemak sapi umumnya digunakan untuk produksi sabun. Penelitian ini bertujuan menganalisis kualitas sabun padat berbahan dasar tallow dengan penambahan ekstrak tea tree dan peppermint dengan taraf yang berbeda. Penelitian menggunakan rancangan acak lengkap yang terdiri dari 4 perlakuan dan 3 ulangan. Perlakuan dalam penelitian ini adalah penambahan ekstrak tea tree dan peppermint pada sabun tallow 0% (P1), penambahan 2% (P2), penambahan 5% (P3), penambahan 8% (P4). Parameter yang diamati adalah kadar air, keasaman pH, asam lemak bebas, dan uji bakteri dengan melihat adanya zona bening pada sabun. Hasil rata-rata yang didapatkan pada penelitian ini ialah kadar air 19,65%, keasaman pH 9,12, asam lemak bebas 0.27% dan ditemukan zona bening terhadap bakteri P.acnes, E.coli and S.aureus., Tallow is an oil obtained from the extraction of cow abdominal fat. Tallow from beef tallow is generally used for soap production. This research aims to analyze the quality of solid soap made from tallow with the addition of tea tree and peppermint extracts at different levels. The research used a completely randomized design consisting of 4 treatments and 3 replications. The treatments in this research were the addition of tea tree and peppermint extracts to tallow soap 0% (P1), addition of 2% (P2), addition of 5% (P3), addition of 8% (P4). The parameters observed were water content, pH acidity, free fatty acids, and bacterial testing by looking at the clear zone in the soap. The average results obtained in this study were water content 19.65%, acidity pH 9.12, free fatty acids 0.27% and a clear zone was found for P.acnes, E.coli and S.aureus bacteria.
Keyword: antibacterial soap, quality solid soap, peppermint, tallow soap, tea tree

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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