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: Analisis Fisikokimia Sabun Berbahan Dasar Tallow Dengan Tambahan Serbuk Kopi Robusta (Coffea canephora) Sebagai Pewangi Alami
Abstrak: Tallow adalah lemak diperoleh dari ekstrak lemak perut sapi. Penelitian ini bertujuan untuk menganalisis sifat fisik dan kimia pada sabun berbahan dasar tallow dengan tambahan serbuk kopi robusta sebagai pewangi alami. Penelitian ini menggunakan rancangan acak lengkap searah yang terdiri dari 3 perlakuan dan 3 ulangan. Perlakuan dalam penelitian ini yaitu penambahan serbuk kopi robusta pada sabun tallow 0% (P1), 20% (P2), 30% (P3). Peubah yang diamati dalam penelitian ini meliputi uji kualitas sabun yang terdiri dari uji pH, uji kadar air, dan uji organoleptik dengan formulasi yang berbeda. Rata-rata hasil yang diperoleh pada penelitian ini adalah kadar air 3,26%, pH keasaman 6,43, dan hasil uji organoleptik yaitu uji hedonik warna (4,23), aroma lemak (3,9), aroma kopi (3,96), keberadaan busa (4,53), daya bersih sabun (4,76) serta uji mutu hedonik yaitu warna (2,66), aroma lemak (3,26), aroma kopi (2,43), keberadaan busa (2,3), dan daya bersih sabun (2,26). Penambahan serbuk kopi robusta pada pengujian kualitas sabun dengan penilaian kadar air dan pH serta uji organoleptik yang dilakukan oleh beberapa panelis sudah sesuai dengan persyaratan mutu kualitas sabun mandi padat pada SNI 3532:2021.
Keyword: kualitas sabun, sabun, sabun lemak, serbuk kopi

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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