Judul: Utilization of Coconut Oil Industrial Liquid  Waste to Become Transparent Solid Soap with Additives Essential Oil Lavender
Abstrak: Limbah cair yang dihasilkan dari proses produksi minyak kelapa di Koperasi W masih memiliki kandungan minyak yang cukup banyak. Minyak dan lemak dalam konsentrasi yang tinggi akan merusak lingkungan terutama pada perairan , hal ini dikarenakan Lapisan minyak dan lemak tersebut akan menghalangi masuknya cahaya matahari sehingga tumbuhan air tidak dapat melakukan fotosintesis. Oleh karena itu perlu dilakukan pemanfaatan kembali minyak yang terdapat dalam limbah cair untuk mengurangi volume dan dampak negatifnya. Salah satu cara yang dapat dilakukan yaitu dengan memanfaatkan kembali minyak dalam limbah menjadi produk sabun padat transparan dengan penambahan essential oil lavender. Dengan melalui tahap desain keteknikan yaitu fase eksplorasi, pendefenisian masalah, ideasi, prototipe dan validasi maka diracang formulasi sabun padat transparan dengan bahan baku minyak kelapa hasil pemurnian limbah. Hasil analisis keragaman terhadap sabun transparan dengan konsentrasi essential oil lavender yaitu F1 sebanyak 0 ml , F2 sebanyak 0,5 ml dan F3 sebanyak 1 ml pada tingkat kepercayaan 95% (α=0,05) menunjukkan bahwa penambahan essential oil lavender berpengaruh nyata terhadap nilai pH dan kekerasan dan tidak berpengaruh nyata terhadap kadar air, dan stabilitas busa. Sebanyak 57% Panelis menyatakan lebih menyukai sampel sabun F3 dikarenakan memiliki aroma lavender yang lebih menyengat, halus, dan meninggalkan kesan kesat setelah digunakan. Analisis kelayakan finansial sabun memiliki hasil B/C ratio 1,7 > 1 sehingga projek ini layak untuk dikembangkan., The liquid waste generated from the coconut oil production process at Cooperative W still contains a significant amount of oil. Oil and fats in high concentrations can have detrimental effects on the environment, particularly in aquatic ecosystems. This is due to the fact that the layer of oil and fats can obstruct the penetration of sunlight, thereby inhibiting aquatic plants from engaging in photosynthesis. Consequently, there is a pressing need to effectively repurpose the oil present within the liquid waste in order to diminish both its volume and its associated negative impact. One viable approach to achieving this objective entails the reutilization of the oil within the waste stream to produce solid transparent soap, complemented by the addition of lavender essential oil. By proceeding through the stages of engineering design, namely the exploration phase, problem definition, ideation, prototyping, and validation, a formulation for solid transparent soap has been meticulously devised, incorporating refined coconut oil obtained from waste as a fundamental raw material. The outcomes of a variance analysis on the transparent soap, varying in concentrations of lavender essential oil (referred to as F1 with 0 ml, F2 with 0.5 ml, and F3 with 1 ml), at a 95% confidence level (α=0.05), affirm that the addition of lavender essential oil significantly influences both pH levels and hardness, while exerting no statistically significant impact on moisture content and foam stability. A notable 57% of the panelists expressed a preference for the F3 soap sample. This preference arises from its pronounced, refined lavender aroma, which culminates in a smooth and refreshing sensation upon application. A financial feasibility analysis of the soap project reveals a B/C ratio of 1.7, exceeding the threshold of 1. Consequently, this project is deemed economically viable for further development.
Keyword: Essential oil lavender, limbah cair, minyak, sabun padat transparan

Judul: Pengaruh Penggunaan Kombinasi Jenis Minyak terhadap Mutu Sabun Transparan
Abstrak: The oil selection as the fatty acid source will determine the transparent soap characteristic because each fatty acid type will gift the different soap characteristic. The use of oil combinations in one formula on the transparent soap made because the characteristic of the oil is not owned by itself but substitute by other oils. Moreover, the probability of the undesirable characteristics on the soap can be reduce until the minimum level to increase the quality of transparent soap. This research is to determine the effect of using the oil combinations on the certain composition, through the transparent soap quality product, to determine the panelist respond through the transparent soap product, to reach the best formula in transparent soap making by using more than one oil combination in one soap formula. The oil that used is coconut oil, RBDPO (refined bleached deodorized palm oil) and castor oil. The diverse analysis shows the different result significantly. The organoleptic test that has been done is to determine the panelist respond through the transparent soap product. Based on the chemicalphysic characteristic and organoleptic test, the best formulas are the transparent soap made from coconut oil and RDBPO with the comparison of 15:5. The sopa characteristic that being made are: water content and evaporate substance (12.13%), fatty acid content (33.41%), unsaponifiable fraction content (1.66%), insolulable in alcohol content alcohol (0.75%), free alkali content as NaOH (0.21%), pH (10.57), hardness (2.10 mm/second), emulsion stability (82.64%), foam stability (33.64%), and cleaning power (285.50 ftu turbidity).
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Judul: Indexing Spatio-Temporal Pada Data Hotspot
Abstrak: The spatial information of hotspot is always changing over time. The recording of these changes makes it necessary to add dimension of time (temporal) into database. The database which is capable to store spatial and temporal information is known as spatiotemporal database. This database is bigger than a normal database because it stores all versions of an object over time and not allowed data to be physically deleted. A large database size causes it’s search time increases. It makes an access structure is needed in spatiotemporal database. Indexing is one of the access structure applied in the spatiotemporal database that accelerates data searching process. Spatiotemporal indexing method consists of two parts namely spatial indexing which is based on geographical information, and temporal indexing which is based on data timing information. The process of hotspot data indexing will be done in this research by using R-Tree approach for spatial data and Change Temporal Index (CTI) for temporal data. R-Tree is a hierarchical, height-balanced external memory data structure for multidimensional object. The hierarchical of R-Tree based on list of administrative such as regency, provinces and island. Change Temporal Index makes indexed data based on temporal side like valid time. CTI keeps valid data in current database and previous data according to interval valid time in historical database. This research is expected to accelerate the retrieving process in spatiotemporal databases. Spatial indexing makes searching faster up to 70%, temporal indexing makes searching faster up to 35% and spatiotemporal indexing makes searching faster than without indexing up to 50%.
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