A new b Ti alloy was designed and fabricated by powder metallurgy process using pure metallic powders. The addition of Mo and Cr increased the stability of the b phase. By contrast, O promoted a phase formation upon cooling. The addition of 18%Mo and 10%Cr stabilized the b phase into ambient temperature. O increased the critical cooling rate of formation of a phase due to the prediction of the continuous cooling transformation diagram calculated by the Java-based Material Properties software. Sintering and solution treatment also enhanced the alloying behavior of pure powders to their designated chemical compositions. Hardness of the alloy decreased with increasing Mo and Cr content, which led to the decrease of a phase. The Ti-18%Mo-10%Cr alloy exhibited better corrosion resistance than a commercial Ti-6%Al-4%V alloy, which is used as current biomaterial.

This study aimed to investigate the effects of element diffusion on the alloying behaviour and microstructure of a Ti-10%Mo-10%Cr alloy during sintering and furnace cooling. A theoretical calculation of the average diffusion distance for each element was performed to predict the alloying behaviour during sintering and furnace cooling. The Ti-10%Mo-10%Cr alloy was fabricated using a blended element powder metallurgy approach. Micrograph of the samples after sintering showed bright-circle structures and significantly decreased equiaxed structures. The number of plate-like structures increased with prolonged sintering time. Microstructural changes occurred because of element diffusion resulting from the prolonged sintering time. Moreover, the diffusion distance of each element also increased with prolonged sintering time. Although elements can sufficiently diffuse during both sintering and furnace cooling, the diffusion distance during sintering was considerably higher than that during furnace cooling for all elements. The diffusion distances of Cr and Mo were the highest and lowest, respectively, during sintering and furnace cooling. This study showed that alloying behaviour mostly occurred during sintering and was controlled by the diffusion of Mo atoms.

Organic inhibitors have been widely studying to be an alternative corrosion prevention because of its abundance and non-hazardous effect to the environment. One of organic inhibitors which is obtained from plant extract is banana (Musa Paradisica) peel, because it has gallocatechin which is a strong antioxidant. Otherwise, inhibition effectiveness from organic compound decreases during increasing of temperature. However, the addition of other substance like halide ion has provided multiple effect of corrosion inhibitor effectiveness. The addition of the halide ions can enhanced the inhibition efficiency of the organic inhibitors. This research highlights the effect of additional halide concentration to the inhibition effectiveness of Musa Paradisica (banana) peel on API 5 L steel in 3,5% NaCl at temperature 60 0 C. This inhibition performance is investigated using weight loss measurement and electrochemical measurement. Result shows that the maximum inhibition efficiency was observed with the mixture of 500 ppm banana peel waaste extract and 100 ppm potassium iodide at 60 0 C. Also, The blends behaved as mixed type inhibitor. The effectiveness was found to be in order of KI > KBr due to the larger ionic radius in iodide ion.

Kondisi air yang keruh di kawasan Surabaya utara mengakibatkan masyarakatnya tidak bisa menggunakan air tersebut untuk keperluan sehari-hari. Kondisi ini disebabkan karena Surabaya utara merupakan kawasan dekat pantai, adanya pencemaran dari limbah industri dan limbah rumah tangga. Sehingga diperlukan teknologi pengolahan air bersih untuk mengolah air tanah menjadi air bersih. Metode pelatihan yang digunakan adalah presentasi materi dan demostrasi pengolahan air bersih. Untuk mengetahui kompetensi peserta pelatihan dilakukan ujian pretest dan postest. Hasil pelatihan ini menunjukan adanya peningkatan kompetensi, wawasan dan pemahaman Guru dan Siswa SMA Luqman Al-Hakim mengenai proses pengolahan air bersih, hal ini dibuktikan dengan peningkatan nilai dari ujian Pretest dan Postest.

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