Judul: Masalah Perutean Kendaraan Listrik Multi-Perjalanan dengan Keberadaan Stasiun Penukaran Baterai
Abstrak: Dengan meningkatnya kesadaran terhadap emisi gas rumah kaca, masyarakat lebih cenderung menggunakan kendaraan listrik dalam berbagai layanan distribusi. Masalah rute pendistribusian dapat diselesaikan dengan menggunakan Electric Vehicle Routing Problem (EVRP). EVRP merupakan perluasan dari VRP klasik dengan kendala keterbatasan kapasitas baterai sehingga kendaraan listrik diharuskan mengunjungi stasiun penukaran baterai dalam perjalanan. Pada makalah ini akan dijelaskan tentang Multiple Trips Electric Vehicle Routing Problem (MTEVRP) dengan keberadaan Stasiun Penukaran Baterai Kendaraan Listrik Umum (SPBKLU). Kendaraan listrik dapat melakukan lebih dari satu kali perjalanan dalam memenuhi permintaan tiap lokasi. Fungsi objektifnya bertujuan meminimumkan konsumsi energi baterai pada kendaraan listrik serta meminimumkan jarak tempuh, di mana kedua hal tersebut berbanding lurus dengan biaya pengiriman maka dengan meminimumkan kedua hal tersebut secara otomatis dapat meminimumkan biaya pengiriman. Permasalahan ini akan diselesaikan dengan metode eksak yaitu Integer Linear Programming., In connection with the increasing awareness of greenhouse gas emissions, people are more inclined to use electric vehicles in various distribution services. The distribution route problem can be solved using the Electric Vehicle Routing Problem (EVRP). EVRP is an extension of the classic VRP with the constraint of limited battery capacity so that electric vehicles are required to visit recharging stations on the way. In this study, we will explain the Multiple Trips Electric Vehicle Routing Problem with Battery Swapping Stations. The electric vehicle can make more than one trip to fulfill the demand of each location. The objective function is minimizing the electric vehicle's battery energy consumption and the travel distance, both of which are directly proportional to the shipping cost, so minimizing these two things can automatically minimize the shipping cost. This problem will be solved with an exact method: Integer Linear Programming.
Keyword: battery swapping stations, electric VRP, exact method, multiple trips, MTEVRP

Judul: Multi-Depot Electric Vehicle Routing Problem with Time  Windows
Abstrak: Dunia sedang menghadapi masalah perubahan iklim yang salah satu penyebabnya adalah emisi gas rumah kaca. Emisi gas rumah kaca dapat dikurangi dengan menggunakan kendaraan listrik. Kendaraan listrik memiliki jarak tempuh yang terbatas. Oleh karena itu, perlu dilakukan penentuan rute optimal, salah satunya adalah penentuan rute kendaraan listrik multi-depot dengan time windows. Tujuan dari penelitian ini adalah memodelkan masalah penentuan rute kendaraan listrik multi-depot dengan time windows dalam model MDEVRPTW dan menyelesaikannya dengan mixed integer linear programming. Biaya yang diminimumkan meliputi biaya tetap kendaraan, biaya perjalanan, biaya pengisian daya, dan biaya penalti jika melanggar time windows. Kendaraan diperbolehkan melanggar time windows dengan toleransi waktu 5 menit dari time windows setiap lokasi. Model ini diimplementasikan dalam dua kasus yang dibagi menjadi lima skenario per kasus. Setiap skenario memiliki perbedaan dalam kapasitas baterai, kapasitas muatan, dan time windows pelanggan. Pada kasus pertama, kendaraan harus kembali ke depot asalnya, sedangkan pada kasus kedua, kendaraan bisa kembali ke depot terdekat. Solusi yang dihasilkan berupa rute kendaraan listrik yang meminimumkan total biaya untuk setiap skenario dan kasus, dan memenuhi semua kendala yang ditetapkan., The world is currently facing the issue of climate change, one of the causes is greenhouse gas emissions. Greenhouse gas emissions can be reduced by using electric vehicles. However, electric vehicles have a limited range. Therefore, it is necessary to determine the optimal route, one of which is the multi-depot electric vehicle routing problem with time windows. The aim of this research is to model the multi-depot electric vehicle routing problem with time windows in the MDEVRPTW model and solve it using mixed integer linear programming. The costs minimized in this problem include vehicle fixed costs, travel costs, charging costs, and penalty costs for violating time windows. Vehicles are allowed to violate time windows with a tolerance of 5 minutes. This model is implemented in two cases, each divided into five scenarios. Each scenario differs in vehicle battery capacity, vehicle load capacity, and customer time windows. In the first case, vehicles must return to their original depot, while in the second case, vehicles can return to the nearest depot. The result is the electric vehicle route that minimizes total costs for each scenario and case, and meets all the specified constraints.
Keyword: time windows, electric vehicle, MDEVRPTW, depot

Judul: Waxes, policosanols and aldehydes in sugarcane (Saccharum officinarum L.) and okinawan brown sugar (kokuto)
Abstrak: Waxes, long chain alcohols and aldehydes were found in several variants of sugarcane (Saccharum officinarum L.) and Kokuto, a non-centrifuged Okinawan cane brown sugar. Long chain alcohols, policosanols, have been reported to have beneficial effect to human health. The composition of wax in sugarcane was analyzed using HPLC with an evaporative light scattering detector. Sugarcane wax composed of 55–60% aldehydes, sterol esters and wax esters, 32–40% alcohols, and small amounts of triacylglycerols, acids and sterols. Extraction of policosanols performed effectively with hexane and methanol (20:1 v/v), while that of long chain aldehydes was with chloroform and methanol (2:1 v/v). Their composition was determined using GC with a flame ionization detector, whereas their compounds were identified using GC-MS. Sugarcane rinds contained up to 500 mg policosanols and 600 mg aldehydes per 100 g sample of Ni 22 cultivar. The content of policosanol and long chain aldehyde in Kokuto was influenced by its production systems. Compositional analysis of the end product confirmed the presence of policosanols and aldehydes up to 85 mg and 8 mg respectively per 100 g sample of Kokuto A, a product of brown sugar manufacture with open pan heating system. Octacosanol and octacosanal were found to be the major wax components in both sugarcane and Kokuto samples. This study revealed significant difference in content and composition of waxes, policosanols and long chain aldehydes between sugarcane parts, cultivars and harvesting times; also between Kokuto types and production methods.
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