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Abstrak :
Kekuatan tarik ultima, kekuatan tekan ultima, kekuatan lentur ultima, dan kekuatan geser lamina satu arah, bersama dengan kekuatan geser dan perilaku kelelahan laminate arah beragam, akan menjadi subjek utama dari studi ini. Untuk menciptakan bahan komposit yang berkelanjutan, serat rami, yang dikenal dengan kekuatan tarik yang sangat baik dan ramah lingkungan, akan dicampur dengan asam polilaktat (PLA) yang dapat terurai secara alami. Pengujian mekanis yang telah diatur sebelumnya akan menilai karakteristik tarik, tekan, lentur, dan geser komposit di bawah pengaturan yang terkontrol, mengungkapkan seberapa baik bahan tersebut dapat menahan tekanan yang umum dalam aplikasi prostetik. Kegunaan prostetik bergantung pada daya tahan bahan selama tekanan siklus, yang dapat diketahui dengan menganalisis perilaku kelelahan menggunakan penilaian kurva S-N. Diharapkan studi ini akan menunjukkan bahwa komposit Rami-PLA dapat digunakan sebagai pengganti yang layak dan efisien untuk prostetik anggota tubuh bawah, sehingga memajukan bidang teknologi prostetik. ......The ultimate tensile strength, ultimate compressive strength, ultimate flexural strength, and shear strength of unidirectional lamina, along with the shear strength and fatigue behavior of multidirectional laminate, will be the main subjects of this investigation. To create a sustainable composite material, ramie fibers, known for their excellent tensile strength and environmental friendliness, will be mixed with biodegradable polylactic acid (PLA). Prearranged mechanical testing will assess the composite's tensile, compressive, flexural, and shear characteristics under controlled settings, revealing how well it can tolerate stresses common to prosthetic applications. Prosthetic usefulness depends on the material's durability during cyclic stress, which can be ascertained by analyzing the fatigue behavior using S-N curve assessments. It is anticipated that this study will show that Ramie-PLA composites could be used as a viable and efficient substitute for lower limb prosthetics, advancing the field of prosthetic technology.

Abstrak :
Bekisting merupakan salah satu komponen penting yang banyak digunakan khususnya pada konstruksi bangunan beton. Penggunaan kayu sebagai material penyusun bekisting masih sangat umum digunakan di Indonesia dan menimbulkan limbah konstruksi yang tidak dapat digunakan kembali. Dalam upaya mengurangi limbah kayu tersebut, pemanfaatan limbah plastik jenis HDPE (High-Density Polyethylene) sebagai bahan baku untuk produk bekisting dapat menjadi sebuah solusi. Penelitian ini mengamati pengaruh bukaan pada balok rangka polimer HDPE dan perbandingannya dengan balok solid tanpa bukaan. Dilakukan perbandingan analisa properti mekanik kuat lentur dari balok bekisting HDPE dengan metode DIC (Digital Image Correlation) dengan pemodelan numerik menggunakan ABAQUS. ......Formwork is one of the essential components widely used, especially in concrete building construction. The use of wood as the material for formwork is still very common in Indonesia and generates construction waste that cannot be reused. In an effort to reduce wood waste, utilizing HDPE (High-Density Polyethylene) plastic waste as a raw material for formwork products can be a solution. This study observes the effect of openings in HDPE polymer truss beams and compares them with solid beams without openings. A comparison of the mechanical flexural properties of HDPE formwork beams is carried out using the DIC (Digital Image Correlation) method with numerical modeling using ABAQUS software.

Abstrak :
Steel fiber dan Hollow-core-slab merupakan inovasi-inovasi baru yang telah banyak diterapkan dalam dunia konstruksi. Berdasar pada teori tegangan lentur di tengah penampang yang sama dengan nol, maka dibuat void pada tengah penampang untuk mengurangi volume beton adalah tujuan dari HCS. HCS yang pada umumnya diproduksi dalam bentuk precast dengan perkuatan pretegang membuatnya mahal untuk diaplikasikan. Maka dilakukan penelitian ini, yaitu HCS dengan sistem pengecoran insitu dan tanpa prategang yang memanfaatkan limbah botol air mineral sebagai pembuat lubang. Telah diketahui dari berbagai penelitian bahwa steel fiber meningkatkan secara signifikan kuat geser, kuat tarik belah, dan kuat lentur dari beton. Maka dalam penelitian ini peningkatan kekuatan lentur dari struktur digunakan bahan tambah steel fiber dengan variasi volume fraksi 0,19% dan 0,32%. Penelitian ini menggunakan benda uji pelat berukuran 15 cm x 60 cm x 175 cm yang dibebani hingga mecapai kekuatan lentur maksimum. Didapatkan bahwa dengan komposisi steel fiber 0,19% terdapat peningkatan kekuatan sebesar 19%-22%, sedangkan untuk komposisi 0,32% peningkatan kekuatan berkisar 26%-42%. ......Steel fiber and Hollow-core-slab are some new innovations that has been widely applied in the construction world. Based on the theory of bending stress section in mid-area which is equal to zero, then the void could be created in the middle section to reduce the volume of concrete. HCS are generally produced in precast with prestressed then made it expensive to apply. Then carried out this research, to try HCS with cast-in-site system and using waste of mineral water bottle for made the hole. It is known from various studies that steel fiber significantly increasing the shear strength, split tensile strength, and flexural strength of concrete. So in this research, to increasing flexural strength of structure, steel fiber added with 0,19% and 0,32% fraction volume. The dimension of slab that used in this research ais 15cm x 60 cm x 75 cm which weighed up to maximum flexural strength. It was found that the composition of 0,19 % steel fibers increase strength by 19%-22%, while for the 0,32% steel fiber composition increase strength ranged by 26%-42%.

Abstrak :
Objective: The aim of this study was to investigate the effect of immersion time in artificial saliva on the flexural strength of provisional crown and bridge (p-c&b) materials. Materials and Methods: Two types of p-c&b materials were used in this study: Light polymerized p-c&b material (Revotek LC) and autopolymerized p-c&b material (PerfecTemp II). A total of 100 specimens were fabricated and measured according to ISO 4049/2000. A stainless steel mould was used to prepare 2mm x 2mm x 25mm bar shaped specimens. All materials were dispensed and manipulated according to the manufacturers' instructions. The specimens were divided into 5 groups (n=10). Each specimen of the first group was measured immediately after preparation. The second, third, fourth and fifth groups were immersed in artificial saliva at 37°C in an incubator for 1 hour, 1 day, 7 days, 14 days, respectively. Flexural strength was tested by Universal Mechanical Testing Machine Shimadzu in a 3-point bending test. The Repeated ANOVA and Post-Hoc Bonferroni test were used to compare the continuous variables between the groups. Result: The results showed flexural strength of Revotek LC were higher than PerfecTemp II achieved the highest value in 7 days. Conclusion: Flexural strength of p-c&b materials were influenced by immersion time in artificial saliva and the type of p-c&b materials.

Abstrak :
ABSTRAK Latar Belakang : Ekstrak Biji AnggurEBA mengandung proantosianidin sebagai pengikat silang kolagen yang menentukan sifat mekanik dentin. Tujuan : Menganalisis pengaruh larutan EBA terhadap kekuatan lentur dentin saluran akar. Metode : 90 lempeng dentin saluran akar dibagi menjadi 3 kelompok direndam larutan EBA, NaOCl dan aquabides. Dilakukan uji kekuatan lentur dentin dengan Universal Testing Machine. Hasil : Kekuatan lentur tertinggi pada kelompok larutan EBA, terendah pada kelompok NaOCl. Tidak terdapat perbedaan bermakna antara kelompok larutan EBA dan aquabides (p>0.05). Kesimpulan : Nilai kekuatan lentur dentin saluran akar pada larutan EBA lebih tinggi dibandingan dengan larutan NaOCl.

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ABSTRACT Background : Grape Seed Extract (GSE) contains proanthocyanidin as collagen crosslinking which determines the mechanical properties of dentin. Objective: To analyze the effect of the GSE solution to the flexural strength of root canal dentin. Methods : 90 root canal dentin slabs were divided into 3 groups, immersed in GSE solution , NaOCl and aquabidest . Dentin flexural strength test measured by Universal Testing Machine. Results : The highest flexural strength was found in GSE solution group , the lowest in the group of NaOCl . There were no significant differences between GSE groups and aquabidest group ( p > 0.05 ). Conclusion : The value of flexural strength of root canal dentin found in GSE solution group was higher when compared with NaOCl solution.

Abstrak :
Bekisting yang merupakan penyumbang limbah konstruksi terbesar, dan sampah plastik di Indonesia yang terus meningkat tiap tahunnya memerlukan solusi penanganan yang tepat. Dapat digunakan limbah plastik jenis HDPE (High-Density Polyethylene) di Indonesia sebagai bahan baku untuk produk bekisting. Pada penelitian ini akan dilakukan perbandingan analisa properti mekanik kuat lentur balok bekisting HDPE dengan tambahan metode DIC (Digital Image Correlation) dengan pemodelan numerik menggunakan ABAQUS. Hasil dari penelitian ini diharapkan dapat memberikan solusi alternatif bahan bekisting dari HDPE yang kuat dan lebih ramah lingkungan. ......Formwork, which is one of the largest contributors to construction waste, and plastic waste in Indonesia, which continues to increase every year, require appropriate handling solutions. HDPE (High-Density Polyethylene) waste in Indonesia can be used as raw material for formwork products. This study will compare the mechanical properties, specifically the flexural strength of HDPE formwork beams, using the Digital Image Correlation (DIC) method and numerical modeling with ABAQUS. The results of this study are expected to provide an alternative solution for formwork materials from HDPE that are strong and more environmentally friendly.

Abstrak :
The oral health of denture wearers depends on the cleanliness of their denture. Therefore, it needs proper care and maintenance to prolong the denture wearing, while the oral mucosa is kept healthy. Maintenance and cleaning the denture by brushing and immersing in desinfectant solution is done to eliminate microorganims. Themoplastic nylon is widely used as material of choice in constructing partial or full denture instead of acrylic resin heat-cured material. This material is superior due to good esthetic, thinner denture base compared with acrylic resin denture base, and alternative material for patient allergic to acrylic monomer. Based on findings, immersion in disinfectant solution for 24 hours can increase the rigidity of nylon denture base material. Refer to those, a research was done to discover the effect of chlorhexidine gluconate 0,2% and sodium hypoclorite 1% disinfectant solution to flexural strength of thermoplastic nylon material, bearing in mind that a those solution are available abundantly in less price. ln this research it is concluded that flexural strength of thermoplastic nylon material is increased in sodium hypochlorite 1% immersion compared to chlorhexidine gluconate 0,2%, aquadest immersion, and control group. Flexural strength of thermoplastic nylon material in chlorhexidine gluconate 0,2% and aquadest immersion are relatively equal. (p=1,000). Hereby disinfectant solution could effect to flexural strength of thermoplastic nylon material. Chlorhexidine gluconate 0,2% and aquadest immersion can decrease flexural strength compared to control group (p=0,000). Anticipation on physical, mechanical, and chemical changes of denture made from thermoplastic nylon material rises a need of socialization among dentist that thermoplastic nylon material can change at immersion in sodium Hypochlorite 1% and chlorhexidine gluconate 0,2% solution. To this matter, further research of other disinfectant solutions needs to be done.

Abstrak :
Kemampuan beton dalam menahan tegangan tarik lebih kecil dibandingkan dalam menahan tegangan tekan. Kekuatan tarik ini dapat menimbulkan keretakan pada beton. Kuat tarik pada beton harus ditingkatkan dengan menggunakan serat kawat ke dalam campuran beton sejumlah proporsi berat terhadap semen. Pengujian tarik belah dan lentur dilakukan secara eksperimental dalam laboratorium. Untuk uji tarik belah dilakukan pada hari ke-7, 14, dan 28. Ukuran dari benda uji tarik belah yaitu silinder 15 x 30 cm. Pengujian lentur dilakukan menggunakan balok ukuran 15 x 15 x 60 cm. Spesimen diuji dengan konfigurasi lentur murni pada umur 14 dan 28 hari. Berbagai variasi serat kawat yang digunakan sebagai persentase volume untuk kadar semen yaitu 4%, 6%, 8%, 10%, dan 12%. Jenis serat kawat yang digunakan yaitu kawat bendrat. Hasil penelitian menunjukkan bahwa kemampuan menahan tarik dalam beton berserat mengalami peningkatan. Dari hasil pengujian, didapatkan bahwa variasi yang menunjukkan peningkatan paling besar yaitu 6%. Untuk kuat tarik belah terjadi peningkatan sebesar 36,89% dan untuk kuat lentur terjadi peningkatan sebesar 46,06%. Dengan menggunakan regresi polinomial, didapatkan persentase kadar maksimum yang lebih akurat. Untuk tes tarik belah kadar maksimum kawat bendrat sebesar 5,4 % dan untuk tes lentur sebesar 5,7%. Untuk perbandingan antara kuat tarik belah dengan kuat tekan beton dengan kawat bendrat menghasilkan koefisien perbandingan antara 0,480 ? 0,653. Sementara perbandingan antara kuat lentur dan kuat tekan beton kawat bendrat memiliki koefisien dalam kisaran 0,74 ? 1,07. Sedangkan perbandingan antara kuat tarik belah dan kuat lenturnya pada beton kawat bendrat memiliki koefisien antara 0,61 ? 0,65. ......The capability of normal concrete to resist tensile stress is weaker than that of it to the compressive stress. As the capacity of tensile strength of concrete affect to the happening of crack growth, this tensile strength has to be improved by using some amount of steel fiber into concrete mixtures in weight proportion to the cement content. Splitting and flexural research has been conducted by set of laboratory experimental work. Testing speciments for splitting tensile tests performed at 7, 14, and 28 days. Size of cylinder speciment for splitting tensile test is 15 x 30 cm. A flexural research done to numbers of beam specimens size of 15x15x60 cm tested under pure bending configuration at the age of 14 and 28 days. Various proportions of steel fiber as volume percentage to cement content were chosen to be 4%, 6%, 8%, 10%, and 12% and the type of steel fiber is replaced by annealed wire. The research outcomes show that the capacity of this type of fibered concrete is physically improved. From the result of test, it was found that the variation which shows maximum increase is 6%. For splitting test the increase is 36,89% and for flexural test has 46,06% increase. Polynomial regression can found the maximum percentage more accurately. By using this, we found for splitting tensile strength, the maximum percentage is 5,4% and for flexural test, we found that maximum percentage is 5,7%. For comparison between splitting test and compressive strength of steel fiber concrete has coeffiecient 0,480 ? 0,653. While the comparison between flexural test and compressive strength has coefficient 0,74 ? 1,07. Then, for comparison bertween splitting test and flexural test of steel fiber concrete has coefficient between 0,61 to 0,65.

Abstrak :
Skripsi ini membahas mengenai perilaku lentur papan laminasi dengan bahan karton minuman daur ulang yang menggunakan perekat urea formaldehida. Tujuan dari penelitian ini adalah untuk menentukan alternatif untuk mendaur ulang bahan-bahan dengan membuat papan dari cacahan karton aseptik yang akan dilaminasi menggunakan perekat urea formaldehida dan untuk mengetahui perilaku lenturnya. Dalam membuat papan panel, cacahan karton aseptik dicampur dengan 0%, 2,5%, 5%, dan 7,5% phenol formaldehida dan kemudian dikompresi dengan tekanan 25 kg/cm2 dan dipanaskan pada 170°C. Hal ini dihasilkan panel dengan phenol formaldehida 0% memberikan kuat lentur terbaik. Panel-panel tersebut kemudian direkatkan dengan urea formaldehida, untuk membuat papan dua lapisan dengan masing-masing ketebalan 10 mm dan tiga papan lapisan masing-masing dengan ketebalan 8 mm. Papan berlapis tersebut kemudian dibandingkan dengan yang dilem dengan epoksi sebagai perekat dingin dalam hal sifat mekanik yaitu modulus elastisitas (MOE) dan modulus pecah (MOR). Pengujian prosedur sifat fisik dan mekanik dilakukan dengan menggunakan standar JIS A 5908: 2003 dan ASTM C 580-02. Hasil dari penelitian nilai MOE dan MOR papan laminasi aseptik menggunakan perekat urea formaldehida lebih tinggi dari papan laminasi dengan perekat dingin epoksi. ......This final project discussed the flexural behavior of recycle beverage carton lamina using urea formaldehide adhesive. The objectives of this research were to determine an alternative to recycle those materials by making shredded aseptic carton laminated board using urea formaldehide adhesive and to find out its flexural behavior. In making panel board, shredded aseptic cartons were mixed with 0%, 2.5%, 5%, and 7.5% phenol formaldehyde and later compressed with a pressure of 25 kg/cm2 and heated under 170°C. It is found that panel with 0% phenol formaldehyde gave the best flexural strength. Those panels were then glued with urea formaldehyde, in order to make a two layers board containing each with 10 mm thickness and a three layers board each with 8 mm thickness. Those layered boards were then compared to those glued with epoxy as cold adhesive, in term of mechanical properties of modulus of elasticity (MOE) and modulus of rupture (MOR). Testing procedures of physical and mechanical properties were performed by using standard JIS A 5908: 2003 and ASTM C 580-02. MOE and MOR values of aseptic laminated board using urea formaldehyde adhesive was higher than those with a epoxy adhesive.

Abstrak :
Pelat bipolar memiliki berat 60-80% dari berat berat total sel tunam dan berfungsi sebagai penghantar elektron serta menopang komponen sel tunam lainnya sehingga pelat bipolar diharapkan mempunyai konduktivitas dan sifat mekanis yang baik. Pelat bipolar dibuat dengan mencampurkan limbah grafit electric arc furnace (EAF), carbon black, dan resin epoksi sehingga tercipta suatu pelat dari karbon-karbon komposit. Grafit bertindak sebagai matriks sedangkan carbon black sebagai filler dan resin epoksi berfungsi sebagai binder. Grafit yang digunakan mempunyai ukuran partikel 53 μm, sedangkan untuk carbon black digunakan kombinasi antara ukuran partikel 44μm dan 37 μm dengan perbandingan 100:0; 90:10; 80:20; 70:30. Pelat bipolar dicetak dengan metode compression moulding pada tekanan 450 kg/cm2 dan temperatur 70°C selama empat jam. Penambahan carbon black 37 μm ke dalam campuran carbon black 44 μm dan grafit 53 μm terbukti mampu meningkatkan konduktivitas dan menurunkan porositas. Konduktivitas paling tinggi terdapat pada pelat bipolar dengan penambahan carbon black 37μm 30% sebesar 15,7 x 10-4 S/cm dan porositas paling rendah terdapat pada pelat bipolar dengan penambahan carbon black 37μm 20% yang menghasilkan porositas sebesar 0.71%. Namun untuk kekuatan fleksural, semakin banyak penambahan carbon black 37 μm kekuatan fleksural semakin menurun. Kekuatan fleksural optimum terdapat pada carbon black 37 μm 0% dengan kekuatan sebesar 20,85 MPa. Penambahan carbon black 37μm 30% meningkatkan densitas pelat hingga 1.73 g/cm3. ......The weight of bipolar plate has 60-80% of total fuel cell stack weight and also as the support of all the component in fuel stack, with the reason of that bipolar plate should has good conductivity dan better mechanical properties. Bipolar plate is made from the mixture of graphite, carbon black, and epoxy resin. The mixture is called carbon-carbon composite. The matrix is the graphite, carbon black as the reinforcement and resin epoxy as a binder. The size of graphite is 53 μm and carbon black are the combination of 44 μm and 37 μm particle size with the comparation 100:0; 90:10; 80:20; 70:30. Bipolar plate is made with compression moulding method, the pressure is 450 Kg/cm2 and 70°C temperature for four hours. The increasing of 37μm carbon black in the combination of 44μm carbon black and 53μm graphite can increase the conductivity and reduce porosity. The sampel with 30% carbon black 37μ has highest conductivity (15,7 x 10-4 S/cm) and the best porosity (0.71%) is sampel with 20% increasing of 37μm carbon black. But the flexural strength decrease with the increase 37μ carbon black and cannot reach the DOE standard. The increase of 37μm carbon black also raise the density of sample until 1,73 g/cm3 with increasing 30% of 37μm carbon black.