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Abstrak :

Pengembangan dari teknologi 3D Printing dalam beberapa waktu belakangan ini mengalami peningkatan yang signifikan. Dimana, pengembangan dari teknologi 3D Printing memiliki kelebihan lebih efisien dan ekonomis dalam produksi prototype. Pada pengembangannya, teknologi 3D Printing digunakan dalam fabrikasi mikro. Dalam pengembangannya, teknologi 3D Printing, menggunakan filament seperti PLA (Polyactid Acid), ABS (Acrylonitrile Butadiene Styrene), dan PET (Polyethylene Trepthalate), SLA (Stereolithography), dll. Dimana, semua material yang biasanya digunakan tersebut merupakan material polymer. Sehingga, dalam penelitian ini akan dikembangkan Beeswax Printing yang menggunakan material Beeswax sebagai raw materialnya, yang akan digunakan untuk fabrikasi microchannel pada filter paper.

 

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The development of additive manufacturing technology in recent years has increased quite rapidly. Where at the beginning the development of additive manufacturing technology its purpose to produce more efficient and economical prototyping products. In its development, the manufacturing additive technology also began to be applied to produce products on a micro scale that commonly used in tissue engineering technology. In the development of manufacturing additive technology, the raw materials most widely ( as known as filaments ) are PLA (Polylactic Acid), ABS (Acrylonitrile Butadiene Styrene), PET (Polyethylene Terephthalate), Thermoplastic Polyurethane, SLA (Stereolithography), etc. All of these materials are polymer materials, so we introduce 3D printers using beeswax for the development of microchannel fabrication on filter paper. However, in this research, beeswax characterization is needed, with various parameters applied in order to control the physical properties of Beeswax, so that it can be used as an alternative material to replace polymeric filaments that commonly used.

Abstrak :
Magnesium Mg dan paduannya terdegradasi secara spontan dalam lingkungan fisiologis melalui peristiwa korosi sehingga berpotensi digunakan sebagai material implan biodegradabel. Namun diperlukan pengendalian laju degradasinya yang masih dianggap terlalu tinggi dalam tubuh manusia. Cara paling efektif dalam mengendalikan laju korosi bahan adalah dengan penambahan lapisan penghalang barrier di permukaan. Pada penelitian ini pengendalian korosi dilakukan dengan teknik anodizing untuk menghasilkan lapisan anodik oksida penghalang dan diuji coba pada paduan komersil AZ31. Untuk meningkatkan efisiensi lapisan oksida, dilakukan proses final coating dengan beeswax-colophony resin dengan tujuan menutup pori lapisan anodik oksida. Proses anodizing dilakukan pada tegangan konstan 5 volt dalam elektrolit 0.5 M Na3PO4 pada suhu 30 C 1 C dengan variasi waktu 2, 5, dan 10 menit. Pada waktu 2 menit belum terdeteksi lapisan, sedangkan pada 5 dan 10 menit terukur tebal lapisan 5 dan 11 ? m. Optimasi komposisi campuran beeswax-colophony menghasilkan rasio optimum 60:40, yang selanjutnya digunakan untuk proses final coating. Kinerja lapisan anodizing dan coating diuji dengan metode elektrokimia yaitu potentiodynamic polarization dan electrochemical impedance spectroscopy EIS . Hasil uji elektrokimia divalidasi dengan uji hilang berat secara invitro selama 14 hari dalam larutan ringer laktat pada suhu 37 C. Hasil uji korosi pada paduan AZ31 menunjukkan peningkatan ketahanan korosi bertahap yang diperlihatkan oleh kenaikan potensial korosi berturut-turut: -1.44, -1.42, -1.32, dan -1.19 VAg/AgCl dan penurunan arus korosi 9.11, 5.02, 1.92, 0.18 ? A/cm2 pada kurva polarisasi substrat; setelah coating; setelah anodizing; dan setelah anodizing dan coating. Kecenderungan yang sama diperoleh dari hasil uji hilang berat yang menunjukkan penurunan laju korosi berjenjang dari substrat, setelah coating; setelah anodizing; setelah anodizing dan coating berturut-turut yaitu 1.09, 0.49, 0.13, dan 0.01 mmpy. Hasil tersebut menunjukkan bahwa perlakuan anodizing dan coating terbukti dapat meningkatkan ketahanan korosi paduan AZ31 secara drastis sebesar 100 kali. ......Magnesium Mg and its alloys are spontaneously degraded in physiological environments through corrosion events therefore potentially used as biodegradable implant materials. But it is necessary to control the degradation rate of Mg alloys that is still considered too high in the human body. The most effective way of controlling the corrosion rate of materials is by the addition of a barrier layer on their surfaces. In this study, corrosion control was performed by anodizing technique to produce anodic oxide barrier layer on AZ31 Mg alloy. To improve the coating efficiency, a final coating with beeswax colophony resin was conducted with the purpose to seal the pore in the anodic oxide layer. The anodizing process was carried out at a constant voltage 5 V in 0.5 M Na3PO4 electrolyte at 30 C 1 C with time variations of 2, 5, and 10 min. Within 2 minutes the layer has not been detected, while at 5 and 10 minutes the thicknesses were 5 and 11 m. Optimization of beeswax colophony mixture composition gives optimum ratio of 60 40, which is then used for final coating process. The anodizing and coating performance was tested and by electrochemical methods of potentiodynamic polarization and electrochemical impedance spectroscopy EIS and invitro weight loss method for 14 days, in lactated ringer solution at 37 C. The results of electrochemical test were validated by weight loss method. The corrosion test results in AZ31 alloys showed an increase in gradual corrosion resistance shown by the incremental corrosion potential increase 1.44, 1.42, 1.32, and 1.19 VAg AgCl and decreased corrosion currents 9.11, 5.02, 1.92, 0.18 A cm2 on the substrate polarization curve after coating after anodizing and after anodizing and coating. The same trend is obtained from the weight loss test results indicating a decrease in the tiered corrosion rate of the substrate, after coating after anodizing after anodizing and coating respectively are 1.09, 0.49, 0.13, and 0.01 mmpy. These results show that anodizing and coating treatment has been shown to significantly increase the corrosion resistance of AZ31 alloys by 100 times.

Abstrak :
ABSTRAK
Pengembangan phase change material PCM sebagai media penyimpan termal pada aplikasi bangunan semakin lama semakin meningkat karena mencegah terjadinya pemborosan energi. Akan tetapi dalam aplikasinya, PCM memiliki dua kekurangan utama yakni nilai konduktivitas termal yang rendah dan besarnya penyusutan volume material. Pembentukan shape-stabilized PCM SSPCM dengan penambahan nanopartikel terbukti mampu mencegah kebocoran pada saat perubahan fasa dan meningkatkan nilai konduktivitas termal. Pada penelitian ini, dibentuk SSPCM menggunakan Beeswax sebagai bahan dasar karena memiliki nilai kalor laten yang besar dan Multi-walled carbon nanotubes MWCNT digunakan sebagai bahan pendukung karena nilai konduktivitas termalnya yang tinggi. Terdapat tiga jenis CNT yang dibedakan berdasarkan metode perlakuannya: CNT murni P-CNT , ball milled CNT B-CNT , dan acid treated CNT A-CNT . Komposit Beeswax/CNT divariasikan dalam persentase massa CNT 5 wt. dan 20 wt. . Sampel komposit diuji perubahan struktur dan sifat termalnya yang meliputi kalor laten peleburan, kalor laten pembekuan, titik leleh, titik beku, kalor jenis, konduktivitas termal, dan kestabilan termal. Berdasarkan hasil uji, nilai konduktivitas termal komposit Beeswax/A-CNT meningkat hingga 132 dan tidak menunjukkan perubahan fasa ketika dipanaskan melebihi titik lelehnya.

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ABSTRACT
Phase change material PCM development as thermal energy storage for building envelope is promising for energy utilization. However, there are two major drawbacks on PCM application which are low thermal conductivity and high volume reduction due to phase change transition. This research objective is to develop a shape stabilized phase change material SSPCM as composite which able to prevent leakage during the transition from solid to liquid. Beeswax was being used as PCM because of its high latent heat and Multi walled carbon nanotubes MWCNT as supporting material with high thermal conductivity. There are three types of CNT applied in this research pristine CNT P CNT , ball milled CNT B CNT and acid treated CNT A CNT . Beeswax CNT composite is variated on the mass ratio 5 wt. and 20 wt. . Composite samples were tested from structure modification and thermal performance including latent heat, sensible heat, melting point, solidifying point, thermal conductivity and thermal cycle test. Results show that thermal conductivity of composite increased by 132 and there was no significant phase transition on its melting or solidifying temperature.

Abstrak :
Peningkatan konsumsi energi pada aplikasi bangunan merupakn isu global dunia. Penelitian ini berkaitan dengan pemanfaatan Phase Change Material PCM untuk penyimpanan termal. Konsep ini mendapat perhatian besar sebagai solusi untuk mengurangi konsumsi energi pada aplikasi bangunan. PCM Lilin memiliki kapasitas termal yang tinggi dipelajari dalam penelitian ini. Tujuan dari penelitian in adalah untuk mengukur dan menganalisis sifat termal lilin lebah/graphene sebagai PCM. Titik leleh, kapasitas kalor dan kalor laten diukur menggunakan Differential Scanning Calorimetry DSC , dan konduktivitas termal diukur menggunakan alat ukur konduktivitas meter. Untuk mengetahui perubahan morphologi PCM akibat pengaruh nanopartikel dan viskositasnya juga diteliti. Berdasarkan hasil DSC, kalor laten lilin lebah/graphene meningkat sebesar 22,5 pada 0,3 wt . Konduktivitas termal lilin lebah/graphene adalah 2,8 W/m.K pada 0,3 wt . Dengan penambahan nanographene meningkatkan kalor laten dan konduktivitas termal nano PCM lilin lebah/graphene. Oleh karena itu, berdasarkan hasil penelitian ini, lilin lebah/graphene disimpulkan memiliki potensi untuk digunakan pada aplikasi bangunan dengan harapan dapat mengurangi konsumsi energi.

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Increased energy consumption in buildings is a worldwide issue. This research is concerned with the implementation of a phase change material for thermal storage. This concept has gained great attention as a solution to reduce energy consumption in buildings. Beeswax, which is a phase change material with a high thermal capacity, is investigated in this research. This paper is intended to measure and analyze the thermal properties of beeswax graphene as a phase change material. The melting temperature, thermal capacity and latent heat were determined using differential scanning calorimetry DSC , and the thermal conductivity was investigated using a thermal conductivity measurement apparatus. To discover the change in the physical properties due to the effect of nanoparticles, the viscosity of the material was investigated as well. Based on the result from the DSC, the latent heat of 0.3 wt beeswax graphene increased by 22.5 . The thermal conductivity of 0.3 wt beeswax graphene was 2.8 W m.K. The existence of graphene nanoplatelets enhanced both the latent heat and thermal conductivity of the beeswax. Therefore, based on this result, beeswax graphene is concluded to have the potential to reduce energy consumption in buildings.

Abstrak :
Indonesia merupakan salah satu negara yang memiliki iklim tropis. Dengan cuaca dan suhu ekstrem yang terjadi, hampir di seluruh bangunan menggunakan air conditioner untuk mendapatkan kenyamanan termal. Phase Change Material (PCM) merupakan Thermal Energy Storage (TES) dengan prinsip kerja kalor laten dapat dijadikan salah satu alternatif dalam mengurangi konsumsi energi akibat penggunaan air conditioner di bangunan. Tujuan dari penelitian ini adalah untuk mengetahui karakteristik sifat termal, pada material bangunan yang diintegrasikan dengan material PCM yaitu beeswax. Dengan melakukan pengujian untuk mengetahui pengaruh dari penambahan beeswax ke material bangunan terhadap temperatur yang dihasilkan dan dibandingkan dengan material bangunan tanpa penambahan beeswax. Variasi dari penelitian ini adalah temperatur heater sebagai sumber panas (35, 40, 45 ^oC). Hasil dari penelitian menunjukkan bahwa penambahan beeswax menghasilkan temperatur dinding dalam yang lebih rendah dibandingkan dengan yang tidak ditambahkan beeswax. Dengan konduktivitas termal batako-beeswax yang didapatkan dari hasil pengujian sebesar 0,0211-0,0212 W/m^oC dan difusivitas komposit sebesar 2,89x10-6 m²/s. Hal ini membuktikan bahwa dengan menambahkan PCM pada material bangunan, PCM akan menyerap kalor dan panas yang akan masuk ke ruangan akan tereduksi. ......Indonesia is one of the countries that has a tropical climate. With the weather and extreme temperatures occurring, almost all buildings use air conditioner to get the thermal comfort. Phase Change Material (PCM) is a Thermal Energy Storage (TES) with latent heat working principle can be an alternative in reducing energy consumption due to the use of air conditioner in the building. The purpose of this research is to determine the characteristics of thermal properties in building materials integrated with PCM material namely beeswax. By conducting thermal properties testing to determine the effect of adding a beeswax to the building material to the resulting temperature and compared to the building material without the addition of beeswax. Variations of this research is the temperature of heater as heat source (35, 40, 45 ^oC). The results of the study showed that the addition of beeswax resulted in a lower inner wall temperature compared to those not added by beeswax. With the thermal conductivity of beeswax-concrete composite obtained from the test result are 0.0211-0.0212 W/m ^oC and the composite diffusivity at 2.89x10^-6 m²/s. This proves that by adding PCM to the building material, the PCM will absorb the heat and the heat that enter the room will be reduced.

Abstrak :
Experimentation on and implementation of phase-change materials for thermal storage is attracting increasing attention by those seeking a potential resolution to energy issues. This study investigates beeswax as a high thermal-capacity phase-change material with the objective of analyzing the thermal properties and behaviors of beeswax/CuO nano-PCM. The study uses differential scanning calorimetry apparatus to measure the melting temperature and thermal capacity of nano-PCMs. The study found nano-PCM melting temperatures of 63.62°C, 63.59°C, 63.66°C, 63.19°C, and 62.45°C at 0.05, 0.1, 0.15, 0.2, and 0.25 wt%, respectively. FTIR testing found no chemical reaction between CuO and beeswax. The existence of CuO nanoparticles enhanced thermal conductivity of beeswax but reduced its heat capacity. However, the change in latent heat caused no significant effects in the performance of beeswax/CuO. Thus, the results showed that heat transfer of composite beeswax/CuO melts faster than base phase-change material

Abstrak :
[Salah satu tantangan dalam meningkatkan standar kesehatan di Indonesia adalah masih tingginya angka kelahiran bayi prematur. Upaya penyelamatan bayi yang lahir prematur terhambat oleh beberapa faktor terutama faktor ekonomi yang disebabkan mahalnya biaya perawatan di ruang NICU rumah sakit. Selain itu, distribusi listrik yang belum merata menyebabkan sedikitnya rumah sakit yang menyediakan fasilitas inkubator terutama pada wilayah terpencil di Indonesia. Penggunaan Phase Change Materials dari kelompok organik sebagai elemen pemanas inkubator portable non-elektrik agar aman bagi pernafasan bayi dan mudah pendistribusiannya menjadi salah satu alternatif upaya penyelamatan bayi prematur yang lahir terutama diwilayah yang belum dialiri listrik nasional. Eksperimen ini bertujuan mendapatkan masa PCM yang paling efisien sesuai Standar Nasional Indonesia untuk mendapatkan rentang waktu dan temperatur paling ideal bagi bayi prematur. Juga pengurangan masa PCM akan meringankan bobot inkubator secara total serta mengurangi biaya. Eksperimen dilakukan menggunakan prototype Inkubator Grashof seri-F yang memanfaatkan fenomena konveksi natural dalam proses pemanasan ruang inkubator. Temperatur diukur menggunakan termokopel tipe K yang dihubungkan pada Modul NI9211. Grafik pengukuran digambarkan oleh perangkat lunak Labview 8.5 yang diinstal pada Personal Computer Unit. Hasil eksperimen menunjukkan masa PCM jenis Beeswax sebesar 3kg adalah yang paling efisien dalam penggunaan energi. Aplikasi fin juga membantu mempersingkat waktu tunggu sebelum penggunaan inkubator dan distribusi panas yang lebih merata dalam ruang inkubator. ......One of the challenges in improving health standards in Indonesia is a high number of neonatal birth. Government efforts to save neonatals hampered by several factors especially economic factors caused by high cost of neonatals care in NICU room at the hospital. Moreover, the uneven of electricity distribution cause least hospitals providing incubator facilities, especially for remote areas in Indonesia. The use of Phase Change Materials from the organic group as a heating element for portable non-electric incubator to be safe for the baby's breathing and easy distribution into an alternative rescue efforts, especially premature babies born in the region that has not been electrified nationwide. Experiments aimed at finding the most efficient mass of PCM based on Indonesian National Standard to get the ideal time and temperature range for premature babies. PCM mass reduction also will lighten the weight of the incubator in total as well as reduce costs. Experiments conducted using prototype Incubator Grashof-F series which utilizes natural convection phenomena in the process of incubator space heating. Temperatures were measured using a K-type thermocouple connected to the module NI9211. Measurement chart illustrated by Labview 8.5 software installed on the Personal Computer Unit. The experimental results indicate the mass of 3kg PCM types Beeswax is the most efficient in energy use. Applications fin also help shorten the waiting time before the use of incubators and more even heat distribution within the incubator.;One of the challenges in improving health standards in Indonesia is a high number of neonatal birth. Government efforts to save neonatals hampered by several factors especially economic factors caused by high cost of neonatals care in NICU room at the hospital. Moreover, the uneven of electricity distribution cause least hospitals providing incubator facilities, especially for remote areas in Indonesia. The use of Phase Change Materials from the organic group as a heating element for portable non-electric incubator to be safe for the baby's breathing and easy distribution into an alternative rescue efforts, especially premature babies born in the region that has not been electrified nationwide. Experiments aimed at finding the most efficient mass of PCM based on Indonesian National Standard to get the ideal time and temperature range for premature babies. PCM mass reduction also will lighten the weight of the incubator in total as well as reduce costs. Experiments conducted using prototype Incubator Grashof-F series which utilizes natural convection phenomena in the process of incubator space heating. Temperatures were measured using a K-type thermocouple connected to the module NI9211. Measurement chart illustrated by Labview 8.5 software installed on the Personal Computer Unit. The experimental results indicate the mass of 3kg PCM types Beeswax is the most efficient in energy use. Applications fin also help shorten the waiting time before the use of incubators and more even heat distribution within the incubator., One of the challenges in improving health standards in Indonesia is a high number of neonatal birth. Government efforts to save neonatals hampered by several factors especially economic factors caused by high cost of neonatals care in NICU room at the hospital. Moreover, the uneven of electricity distribution cause least hospitals providing incubator facilities, especially for remote areas in Indonesia. The use of Phase Change Materials from the organic group as a heating element for portable non-electric incubator to be safe for the baby's breathing and easy distribution into an alternative rescue efforts, especially premature babies born in the region that has not been electrified nationwide. Experiments aimed at finding the most efficient mass of PCM based on Indonesian National Standard to get the ideal time and temperature range for premature babies. PCM mass reduction also will lighten the weight of the incubator in total as well as reduce costs. Experiments conducted using prototype Incubator Grashof-F series which utilizes natural convection phenomena in the process of incubator space heating. Temperatures were measured using a K-type thermocouple connected to the module NI9211. Measurement chart illustrated by Labview 8.5 software installed on the Personal Computer Unit. The experimental results indicate the mass of 3kg PCM types Beeswax is the most efficient in energy use. Applications fin also help shorten the waiting time before the use of incubators and more even heat distribution within the incubator.]

Abstrak :
Magnesium (Mg) merupakan logam ringan dan dapat diserap tubuh melalui proses degradasi atau bersifat biodegradable. Namun Magnesium dan paduannya mengalami degradasi yang sangat cepat di dalam lingkungan fisiologis akibatnya kekuatan mekanik dari implan akan menurun. Untuk meningkatkan ketahanan korosi dari paduan magnesium dapat dilakukan dengan metode anodizing. Lapisan oksida yang dihasilkan dari proses anodizing memiliki banyak retakan dan pori pada permukaannya. Retakan dan pori ini dapat ditutup melalui metode sealing beeswax-colophony. Proses anodizing dilakukan pada tegangan konstan 5 volt dalam elektrolit 0.5 M Na3PO4 pada suhu 30°C ± 1°C dengan variasi waktu 10, 20, dan 30 menit. Pada waktu 10, 20, dan 30 menit terukur tebal lapisan 6, 14, dan 16 μm. Optimasi waktu anodizing dihasilkan pada anodizing 20 menit. Untuk mengetahui laju korosi paduan magnesium yang telah di anodizing dan sealing dilakukan dengan uji hilang berat (invitro) selama 14 hari dalam larutan 0,9% NaCl pada suhu 37°C. Hasil uji hilang berat divalidasi dengan uji potentiodynamic polarization. Hasil uji hilang berat yang menunjukkan laju korosi dari substrat; anodizing; substrat + beeswax-colophony sealing; anodizing + hidrotermal sealing; anodizing + beeswax-colophony sealing berturut-turut yaitu 7,91; 6,26; 5,0; 6,06; dan 3,30 mmpy. Hasil uji polarisasi menunjukkan peningkatan ketahanan korosi yang diperlihatkan oleh kenaikan potensial korosi untuk substrat; anodizing; substrat + beeswax-colophony sealing; anodizing + hidrotermal sealing; anodizing + beeswax-colophony sealing berturut-turut adalah -1.49, -1.57, -1.54, -1.43, dan -1,17 VAg/AgCl dan penurunan arus korosi berturut-turut 5.72x10-4, 3.40x10-5, 2.54x10-8, 2.19x10-5 , dan 3.19x10-8 A/cm2. Hasil tersebut menunjukkan bahwa perlakuan anodizing dan sealing dengan beeswax-colophony terbukti dapat meningkatkan ketahanan korosi paduan AZ31 2 kali lipat.

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Magnesium (Mg) is the light metals and absobable materials by the human body through a process of degragradation known as biodegradable. However, Mg and its alloys has a rapid corrosion rate in physiological environtment causes reduction of mechanical properties of implants. Anodizing is widely used to increase corrosion resistance of magnesium alloys. The oxide layer produced while anodizing process has many cracks and porous on its surface. Cracks and porous could covered by beeswax-colophony sealing method. The anodization process was carried out at constant voltage 5 volt in electrolyte of 0.5 M Na3PO4 at 30 ° C ± 1 ° C with variations of time 10, 20, and 30 minutes. The thickness of layer was measured at 10, 20, and 30 minutes are 6, 14, 16 μm respectively. Anodizing time optimization was obtained at 20 minutes. to determine the corrosion rate of anodized and sealed magnesium alloy was carried out by in-vitro test for 14 days on 0.9% NaCl solution at 37 ° C. The results of the weight loss test were validated by potentiodynamic polarization test. The weight loss test results exhibits the rate of corrosion of the substrate, anodizing; substrate + beeswax-colophony sealing; anodizing + hydrothermal sealing; anodizing + beeswax-colophony sealing are 7.91, 6.26, 5.0, 6.06, and 3.30 mmpy respectively. The results of corrosion on AZ31 show by increased corrosion potential, -1.49, -1.57, -1.54, -1.43, and -1.17 VAg/AgCl and decreased corrosion currents, 5.72x10-4, 3.40x10-5, 2.54x10-8, 2.19x10-5, and 3.19x10-8 A/cm2 on the substrate; anodizing; substrate + beeswax-colophony sealing; anodizing + hydrothermal sealing; anodizing + beeswax-colophony sealing. These results prove anodizing and coatings increase corrosion resistance of AZ31 twice.