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Abstrak :
Objective: To compare the importance of storage time and the tooth type for isolation of dental pulp cells (DPCs) from extracted human teeth. Methods: 35 human teeth were used in this study. The teeth were stored in phosphate buffered saline (PBS) after extraction and divided into two groups randomly according to the time elapsed between extraction and isolation. In group one, the isolation was performed within 2 hours and in the other group it was performed 24 hours after extraction. Results: No significant differences between isolation time and total cell counts (p 0.483) and between isolation time and viable cells (p 0.341). No significant differences between the first molar and the premolar related cell counts and viable cells, but both teeth groups showed significant higher viability and had higher total cell amounts than third molars after isolation. Statistically significant correlations were found between age of donors and viable cells and viability after 24 hours isolation time. Conclusion: The immediate isolation of DPCs is not necessary after the tooth extraction. The tooth can be stored in PBS at room temperature up to twenty four hours after the extraction without a significant reduction in cell viability and counts. The cells obtained from younger donors might have more chance for more viability even if storage time was extended. Premolars and first molars were better donors than the third molars for DPCs isolations and the high number of success revascularization rate in premolars with necrotic immature premolars might be because of their high cell viability potentials.

Abstrak :
Renewable energy resources are increasingly being used to cover the demand in the electricity grids in many countries. A question that is currently for most grids rather theoretical, although interesting in introducing a long-term perspective, pertains to what an energy supply from exclusively renewable energy resources could look like. This question has to be answered individually for each grid. The objective of the present paper is to scrutinize the specific challenges that a 100% renewable energy scenario brings for the Java-Bali grid. This objective is achieved by designing power generation time series such that they match a given load time series. An important challenge for a 100% renewable energy supply is the very high dependency on solar energy, which generates an enormous primary power generation fluctuation on both a daily and an annual timescale. In particular the seasonal fluctuations come along with high storage demand, which is the greatest challenge involved in a 100% renewable energy supply. There are strategies that may be used to considerably reduce the storage demand: the installed photovoltaic (PV) capacity can be increased, bioenergy can be used for seasonal balancing, and special long-term storage can be added. These options are considered in the present paper.

Abstrak :
E-waste merupakan salah satu masalah utama di dunia, termasuk Indonesia yang mana memiliki tingkat konsumsi yang tinggi terhadap produk-produk elektronik. E-waste di Indonesia diperkirakan akan semakin meningkat dikarenakan pesatnya perkembangan teknologi dan belum adanya E-waste management yang baik sehingga aliran sampah masih banyak masuk ke sektor informal dan belum dapat dipetakan dengan baik. Untuk dapat memetakan aliran sampah dan jumlah E-waste yang dihasilkan dibutuhkan lifespan dari masing-masing produk elektronik sebagai input. Pada kondisi saat ini, produk-produk elektronik yang telah rusak atau sudah tidak dipakai lagi biasanya tidak langsung dibuang tetapi disimpan dan masuk dalam kategori storage time. Efek dari storage time dapat memperpanjang total lifespan, menurunkan collection rate, dan menurunkan pasokan untuk recycling yang dapat mengganggu sistem E-waste Management. Sehingga model distribusi lifespan untuk mendapatkan persentase sampah yang dihasilkan per tahun dan cara penurunan storage time menjadi kunci penting dalam E-waste Management. Data lifespan didapatkan dari kuesioner survei pada individu dan rumah tangga di Pulau Jawa. Penelitian ini memberikan hasil model distribusi yang better fit terhadap data lifespan dan storage time dan persentase end-of-life per tahun dari produk-produk elektronik di Indonesia dengan penilaian model fit pada Distribusi Normal, Distribusi Lognormal, dan Distribusi Weibull.

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E waste is one of the major problems in the world, including Indonesia which has a high level of consumption of electronic products. E waste in Indonesia is expected to increase due to the rapid development of technology and the absence of proper E waste management so that the flow of waste is still a lot of entry into the informal sector and can not be adequately mapped. To be able to map the flow of waste and the amount of E waste generated, lifespan required from each electronic product as an input. In current conditions, defective or outdated electronic products are usually not directly disposed of but stored or fall into a category of storage time. The effects of storage time can extend the total lifespan, decrease the collection rate, and decrease the supply for recycling that can disrupt the E waste Management system. So the lifespan distribution model to get the percentage of waste generated per year and how to decrease storage time becomes an important key to E waste Management. Lifespan data were obtained from survey questionnaires on individuals and households in Java. This study gives a better fit distribution model for lifespan data, and storage time and percentage of annual end of life electronic products in Indonesia with model fit assessment on Normal Distribution, Lognormal Distribution, and Weibull Distribution.