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Abstrak :
Tujuan: Menganalisis perbedaan microhardness dan flexural strength dentin saluran akar setelah paparan berbagai larutan irigasi endodontik regeneratif. Metode: Tiga puluh enam sampel dentin gigi manusia yang baru diekstraksi dibagi menjadi 6 kelompok yaitu 2 kelompok kontrol (NaCl 0,9%), 2 kelompok uji 1 diirigasi dengan 20 ml NaOCl 1,5% selama 5 menit – 3 ml NaCl 0,9% selama 3 menit – 20 ml EDTA 17% selama 5 menit, 2 kelompok uji 2 diirigasi dengan 20 ml NaOCl 1,5% selama 5 menit – 3 ml PBS 10% selama 3 menit – 20 ml EDTA 17% selama 5 menit – 3 ml PBS 10% selama 3 menit. Perubahan microhardness dan flexural strength dievaluasi dengan uji Vickers dan 3-Point Flexural Tester. Data dianalisis menggunakan One-Way ANOVA dan Tamhane. Hasil: Terdapat perbedaan bermakna antar kelompok uji 1 dan 2 dengan kelompok kontrol (One-Way ANOVA, p < 0,05). Berdasarkan uji Post Hoc (Tamhane, p<0,05) terdapat perbedaan bermakna microhardness dan flexural strength kelompok uji 2 dibandingkan kelompok uji 1, dengan nilai rerata lebih tinggi pada kelompok uji 2 terhadap kelompok uji lainnya. Kesimpulan: Kelompok uji 2 memiliki nilai microhardness dan flexural strength lebih baik sebagai bahan regenerasi endodontik regeneratif. ......Objective: To analyze the differences in microhardness and flexural strength of root canal dentin after exposure various regenerative endodontic irrigation solution. Methods: Thirty-six dentine samples from fresh extracted were assigned to 6 groups, two groups as a control (NaCl 0,9%), two test groups 1 (20 ml NaOCl 1,5% for 5 min – 3 ml NaCl 0,9% for 3 min – 20 ml EDTA 17% for 5 min), two test groups 2 (20 ml NaOCl 1,5% for 5 min – 3 ml PBS 10% for 3 min – 20 ml EDTA 17% for 5 min – 3 ml PBS 10% for 3 min). The changing of microhardness and flexural strength were evaluated using Vickers and 3-point flexural tester. Data were analysed using One-Way ANOVA and Tamhane. Result: There was significant difference between test groups 1 and 2 with control group (One-Way ANOVA, p < 0,05). Based on the Post hoc test (Tamhane, p < 0,05 ), showed significant difference in microhardness and flexural strength between group 2 and group 1, with higher mean in test group 2 compared to other test groups. Conclusion: Test group 2 had better microhardness and flexural strength as regenerative endodontic irrigation.

Abstrak :
ABSTRAK
komposit berpenguat serat alam dapat menjadi alternatif untuk menggantikan komposit berpenguat serat sintetis yang kurang ramah terhadap lingkungan. Serat dari tumbuhan kenaf adalah salah satu serat alam yang dapat dimanfaatkan sebagai pengganti penguat serat sintesis pada komposit. Tujuan dari penelitian ini adalah untuk mengetahui kuat lentur, daya serap air, dan kadar air pada komposit polipropilena berpenguat serat kenaf dengan variasi fraksi berat serat sesuai dengan SNI 01-4449-2006. Serat kenaf diberi perlakuan alkali sebelum digunakan sebagai penguat dengan cara direndam dalam larutan NaOH 5%. Komposit polipropilena/serat kenaf kemudian difabrikasi dengan mesin hot press. Fraksi berat serat yang digunakan pada penelitian adalah 30 wt%, 40 wt%, 50 wt%, dan sampel polipropilena murni juga difabrikasi sebagai pembanding. Komposit yang difabrikasi disebut sebagai papan serat dengan kerapatan tinggi menurut SNI karena memiliki nilai densitas 1,08 g/cc. Kuat lentur, daya serap air, dan kadar air terbaik dimiliki oleh komposit polipropilena/serat kenaf 30wt% dengan nilai masing-masing (4,77 ± 1,00) MPa, (3,61 ± 1,77) % dan (1,12 ± 0,34)%; dan nilai-nilai ini memenuhi Standard Nasional Indonesia (SNI) tentang papan serat.

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ABSTRACT
Natural fiber reinforced composites can be an alternative to replace composites with synthetic fibers reinforcement that are less environmentally friendly. Kenaf fiber which is obtained from kenaf plant is one of natural fibers that can be used as a reinforcement in composites. The purpose of this research was to determine the flexural strength, water absorbent, and water content of polypropylene/kenaf fiber composites with variations of fiber weight fraction according to SNI 01-4449-2006. Kenaf fiber was treated by alkaline treatment before being used as a reinforcement by immersing kenaf fiver in NaOH 5% solution. Polypropylene/kenaf fiber composites were fabricated with compression moulding method using a hot press machine. Fiber weight fractions used in this research were 30 wt%, 40 wt%, 50 wt%, and pristine polypropylene samples were also fabricated as a comparison. Based on SNI, the fabricated composites was called Papan Serat Kerapatan Tinggi (PSKT) because the density value was 1,08 g/cc. The flexural strength, minimum water absorption and water content were found in polypropylene/kenaf fiber composite 30wt% with the value of (4,77 ± 1,00) MPa, (3,61 ± 1,77) % and (1,12 ± 0,34)% respectively and these values met the Fiber Board Indonesian National Standard (SNI).

Abstrak :
This work investigates the fresh, mechanical and durability properties of normal, Self-Compacting Concrete (SCC) and Smart Dynamic Concrete (SDC), which are a new generation of concrete with a lower amount of cementitious content. SDC is a low-fine, self-compacting concrete, that combines the benefits of normal concrete (stability) and self-compacting concrete (fresh properties). Fresh properties such as slump flow, L-box and V-funnel tests were investigated to evaluate its self-compacting properties. Mechanical properties such as compressive, splitting tensile and flexural strengths were also examined to compare its effectiveness with normal concrete. In addition to the fresh and hardened properties, the rapid chloride permeability test was also conducted to check the durability of normal, SCC and SDC concrete mixtures. The test results of the fresh properties clearly showed that SDC exhibited superior flowability in the slump flow, L-box and V-funnel tests within the limits of EFNARC (The European Federation of Specialist Construction Chemical and Concrete Systems) guidelines. The mechanical properties of SDC attained higher compressive strength, splitting tensile strength and flexural strength compared with the normal and SCC concrete mixtures. The rapid chloride permeability tests result of SDC clearly showed that SDC exhibited similar and better results than that of normal and SCC concrete mixtures.

Abstrak :
ABSTRAK
Bahan penyerap radar atau Radar Absorbent Material adalah salah satu material maju untuk keperluan teknologi siluman. Penambahan sejumlah kecil clay terhadap komposit Epoksi/E-Glass telah terbukti dapat membuat bahan penyerap gelombang elektromagnetik lebihbaik dibandingkan bahan komposit Epoksi/E-glass. Penelitian ini, yang merupakan kelanjutan dari penelitian sebelumnya mengenai penyerapan gelombang elektromagnetik, bertujuan mempelajari sifat tarik, sifat tekuk, dan permukaan patahan komposit Epoksi/E-glass/Clay.. Empat jenis sampel dibuat, yaitu, komposit Epoksi/E-Glass dan Epoksi/E-Glass/Clay dengan komposisi clay 1 wt%, 3 wt % ,dan 5 wt %, yang difabrikasi dengan metode hand lay-up. Berdasarkan hasil uji tarik dan uji tekuk, nilai kuat tarik dan kuat tekuk tertinggi diperoleh pada komposit Epoksi/E-glass/Clay dengan fraksi beratclay 3 wt %, yang berturut-turut kenaikan kuat tarik dan kuat tekuknya sebesar 182,24% dan 23,5% terhadap komposit Epoksi/E-glass/Clay. Sedangkan nilai modulus tarik dan modulus tekuk pada komposit Epoksi/E-glass/Clay dengan fraksi berat clay 3 wt % memiliki nilai 11,5 GPa dan 6,04 GPa secara berturut-turut. Pengamatan permukaan patahan menggunakan Scanning Electrons Microscope menunjukkan jenis-jenis mode kegagalan yang terjadi adalah fiber pull-out, delaminasi, kegagalan matriks, fiber patah, dan keretakan mikro pada matriks. Selain itu, sisa matriks yang cukup banyak di fiber pada komposit Epoksi/E-glass/Clay dibanding komposit Epoksi/E-glass menunjukkan ikatan interfacial yang lebih baik saat sejumlah kecil clay ditambahkan.

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ABSTRACT
Radar Absorbent Materials are one of new advanced materials to be used in stealth technology. It was an evidence that the addition of a small amount of clay in Epoxy/E-glass composites provided a better electromagnetic wave absorber materials compared to Epoxy/E-glass composites. This research, which was a continuation of the previous research about electromagnetic wave absorption, aimed to study the tensile and flexural properties,as well as the modes failure of Epoxy/E-glass/Clay composites. Four different samples were made; they were Epoxy/E-Glass and Epoxy/E-Glass/Clay with 1 wt %, 3 wt %, and 5 wt % clay loadings. The samples were fabricated with a hand lay-up method. Tensile and flexural test results showed that the highest tensile and flexural strengths were obtained on the Epoxy/E-glass/Clay with 3 wt % clay?s weight fraction, which was increased up to 182,24 % and 23,5 % respectively from the tensile strength and flexural strength of Epoxy/E-glass composites. The tensile and flexural modulus values of Epoxy/E-glass/Clay composites with 3 wt % clay?s weight fraction were 11,3 GPa and 6,04 GPa respectively. An observation of fracture surface using Scanning Electrons Microscope showed that the failure modes that occurred on the fracture surfaces were fiber pull-out, delamination, matrix failure, fiber fracture, and matrix micro-cracks. Moreover, some amount of remaining matrix on the glass fiber at Epoxy/E-glass/Clay composites compared to Epoxy/E-glass composites showed that a better interfacial bond was obtained when a small addition of clay were added