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"Baja dari sponge bijih besi laterite merupakan produk baja yang dihasilkan PT Krakatau Steel. Baja lembaran ini terbuat dari mineral laterite dengan kandungan Fe sekitar 50 %, Mg, dan Si berkisar pada besaran 20-25 %. Baja ini sudah diaplikasikan di roof (atap) Jembatan TekSas pengubung Fakultas Teknik dan Fakultas Sastra UI. Perilaku korosi baja lembaran dari sponge bijih besi laterite dan baja karbon pada larutan dengan penambahan NaCl sebesar 0 ppm, 100 ppm, 200 ppm, 300 ppm, dan 400 ppm serta larutan dengan pH 4, 5, dan 6 selama waktu perendaman 48 jam, 72 jam, 120 jam, dan 168 jam dilakukan dengan menggunakan pengujian weight loss berdasarkan pada standar ASTM G1-03 dan ASTM G31 ? 72. Selain itu, penelitian ini juga menggunakan teknik analitik seperti pengujian Optical Spectroscopy untuk mengetahui komposisi unsur penyusun kedua baja dan Energy Dispersive X-ray Analysis (EDX) untuk memeriksa komposisi unsur dari produk korosi kedua baja tersebut. Dari hasil penelitian terlihat bahwa semakin meningkatnya waktu perendaman (jam) maka laju korosi (mpy) untuk baja karbon dari bijih besi hematite dan bijih laterite masing-masing berkisar dari 3.5 mpy s/d 10 mpy dan 2.6 mpy s/d 4.2 mpy. Sedangkan dengan semakin meningkatnya penambahan NaCl (ppm) maka laju korosi (mpy) untuk masing-masing baja berkisar dari 3.5 s/d 4.1 mpy dan 2.9 mpy s/d 4.2 mpy serta dengan semakin meningkatnya pH larutan maka laju korosi (mpy) untuk masing-masing baja berkisar dari 14 mpy s/d 5 mpy dan 20 mpy s/d 5 mpy. Jadi, dengan semakin meningkatnya waktu perendaman (jam), konsentrasi NaCl (ppm), dan pH larutan maka ketahanan korosi dari baja laterite hampir sama dengan baja karbon biasa. Selain itu dalam penelitian ini juga diamati pengaruh penambahan NaCl (ppm) dan penurunan pH larutan terhadap degradasi kerusakan yang dihasilkan dari baja laterite dan baja karbon. Analisa dengan metode EDX menyatakan bahwa deposit yang terbentuk di permukaan kedua baja utamanya terdiri atas unsur Fe, O, C, Si, serta sedikit Ca pada baja laterite.

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Steel from sponge laterite iron ore is a product from Krakatau Steel Company. This steel extracted from mineral laterite which contained 50 % Fe, Mg, and 20-25 % Si. Laterite steel is used on roof in TekSas Bridge connecting Technique Faculty and Sastra Faculty University of Indonesia.

Corrosion behaviour of steel sheet from sponge laterite iron ore and carbon steel in solutions with addition of 0 ppm, 100 ppm, 200 ppm, 300 ppm, and 400 ppm NaCl with pH 4, 5, and 6 were studied by using weight lost test based on ASTM G1-03 dan ASTM G 31-72 standard. Beside, this study used analytical techniques such as Optical Spectroscopy to obtain chemical composition data from both steels and Energy Dispersive X-ray Analysis (EDX) to examine composition from corrosion product formed in surface steels.

The experiment showed that with increased immersing time (hour) produced corrosion rate (mpy) to carbon steel and laterite steel are about from 3.5 mpy until 10 mpy and 2.6 mpy until 4.2 mpy. The increase of addition NaCl concentration (ppm) produced corrosion rate (mpy) to both steel are about from 3.5 mpy until 4.1 mpy and 2.9 until 4.2 mpy. An increase in pH solution produced corrosion rate (mpy) to both steel are about from 14 mpy until 5 mpy and 20 mpy until 5 mpy. So, an increased immersing time (hour), the increase of addition NaCl concentration (ppm), and an increased in pH solution makes laterite steel and carbon steel have almost same corrosion resistant.

In addition to this research also study the effect of increasing addition of NaCl concentration (ppm) and a decrease in pH solution to damage degradation carbon steel and laterite steel. From EDX analyses, there were some Fe, C, O, Si along with little Ca compounds in the surface deposit laterite steel."

"[Permintaan terhadap munisi kaliber besar untuk kebutuhan bidang HanKam didalam negeri sangat tinggi. Oleh karena itu, produsen harus mengimpor bahanbaku Cu-Zn 70/30 dari luar negeri dengan harga yang tinggi. Hal ini yangmenyebabkan produsen di dalam negeri berlomba untuk menguasai teknologipembuatan selongsong peluru kaliber besar agar dapat meningkatkan kemandiriandi bidang HanKam supaya biaya produksi menjadi lebih rendah. Salah satunyaadalah menggunakan proses thixocasting untuk menghasilkan preform/mangkukCu-Zn 70/30 dari billet yang dilanjutkan dengan ironing. Keberhasilan prosesironing tergantung dari mampu bentuk dingin material Cu-Zn 70/30 yangdigunakan. Oleh karena itu, pada penelitian ini dipelajari bagaimanameningkatkan mampu bentuk dingin dengan metode thermomechanicalcontrolled processed menggunakan teknologi canai hangat. Teknologi canaihangat dilakukan dengan metode double pass reversible sebanyak 25% x 2, 30%x 2, dan 35% x 2 dengan variabel temperatur 300oC, 400oC, dan 500oC. Denganmelakukan pengamatan metalografi baik menggunakan optical microscopemaupun FE-SEM, pengujian mekanik baik uji tarik maupun uji keras mikrovickers, dan pengujian mampu bentuk dengan swift test menghasilkan kesimpulanyaitu derajat deformasi aktual canai hangat yang dilakukan tidak sesuai denganteoritis, namun dari variabel canai hangat yang dilakukan masih bisa dihasilkansifat mampu bentuk terbaik yaitu pada benda uji yang dideformasi canai hangat ditemperatur 500oC dengan derajat deformasi aktual sebesar 38.7%. Sifat mampubentuk yang tinggi berhubungan dengan sifat mekanik dan struktur mikro yangdihasilkan yaitu ukuran butir halus mencapai 29 μm, berbentuk equiaxed dengannilai GAR mencapai 1.2, dan nilai kekerasan mikro yang tinggi mencapai 155HV. Selain itu, kekuatan UTS dan YS tertinggi masing-masing sebesar 533 MPadan 435 MPa juga didapatkan dari benda uji yang dilakukan parameter deformasicanai hangat di temperatur 500oC dengan derajat deformasi aktual 38.7%.Sedangkan apabila dilihat dari sifat mampu bentuknya maka benda uji yangdideformasi canai hangat pada kondisi parameter ini memiliki nilai koefisienpengerasan regang yang tinggi sebesar 0.00228, nilai anisotropi normal rata-ratayang tinggi sebesar 0.5452, nilai anisotropi planar (Δr) yang rendah yaitu Δr<1sebesar -0.42, LDR tinggi sebesar 2.625, dan tinggi mangkuk terbesar yaitu 10.31mm.;The needs of high calibre munition for Indonesian army is very high. Tofulfill this strategic requirement, the government has to import this munition eventhe price is very high. This condition stimulates local industry to obtain the latesttechnology to produce high calibre munition, especially on casing. It is expectedthat the price will be lower by producing high calibre munition in Indonesia. Onof technology which is used to produce high calibre casing munition isthixocasting to produce pre-formed cup of Cu-Zn from billet then followed byironing process. The quality result of ironoing process is mostly dependent oncold formability of Cu-Zn 70/30 material used. Therefore, this research focuses tostudy how to improve cold formability by implemented thermo mechanicalcontrolled processed with warm rolling. Warm rolling is conducted on doublepass reversible method with deformation 25% x 2, 30% x 2, and 35% x 2 atvarious temperatur 300oC, 400oC, and 500oC. The specimens are then examinedand tested by several method such as metallography using optical microscopy andFE SEM, tensile test, vickers hardness test and swift test to observed coldformability. The result indicate that the aktual degree of deformasi of warmrolling can not be achieved as planned due to some problems with the equipment.However, the best formability can be measured, where the best formability isobtained for specimens which were warm rolled at temperatur 500oC with aktualdeformation 38.7%. Formability is strongly related to the mechanical propertiesand its microstructure where the best formability obtained for the specimenswhich has 29 μm grain size in equiaxed form and has GAR value of 1.2, andmaximmum hardness value is 155 HV. This specimen has UTS and YSmaximum are 533 MPa and 435 MPa, maximum strain hardening coefficient0.00228, average anisotropic 0.5452, anisotropic planar Δr<1 at -0.42, LDRmaximum 2.625, and the height of cup is 10.31 mm., The needs of high calibre munition for Indonesian army is very high. Tofulfill this strategic requirement, the government has to import this munition eventhe price is very high. This condition stimulates local industry to obtain the latesttechnology to produce high calibre munition, especially on casing. It is expectedthat the price will be lower by producing high calibre munition in Indonesia. Onof technology which is used to produce high calibre casing munition isthixocasting to produce pre-formed cup of Cu-Zn from billet then followed byironing process. The quality result of ironoing process is mostly dependent oncold formability of Cu-Zn 70/30 material used. Therefore, this research focuses tostudy how to improve cold formability by implemented thermo mechanicalcontrolled processed with warm rolling. Warm rolling is conducted on doublepass reversible method with deformation 25% x 2, 30% x 2, and 35% x 2 atvarious temperatur 300oC, 400oC, and 500oC. The specimens are then examinedand tested by several method such as metallography using optical microscopy andFE SEM, tensile test, vickers hardness test and swift test to observed coldformability. The result indicate that the aktual degree of deformasi of warmrolling can not be achieved as planned due to some problems with the equipment.However, the best formability can be measured, where the best formability isobtained for specimens which were warm rolled at temperatur 500oC with aktualdeformation 38.7%. Formability is strongly related to the mechanical propertiesand its microstructure where the best formability obtained for the specimenswhich has 29 μm grain size in equiaxed form and has GAR value of 1.2, andmaximmum hardness value is 155 HV. This specimen has UTS and YSmaximum are 533 MPa and 435 MPa, maximum strain hardening coefficient0.00228, average anisotropic 0.5452, anisotropic planar Δr<1 at -0.42, LDRmaximum 2.625, and the height of cup is 10.31 mm.]"

"Obesitas menjadi masalah besar dewasa ini terkait dengan lebih dari 3 juta kematian terjadi akibat komplikasinya. Diet seimbang dengan restriksi kalori, sebagai manajemen obesitas, perlu mempertimbangkan produksi makanan sustainable terkait isu perubahan lingkungan, ketahanan pangan, dan keanekaragaman hayati. Aplikasi seluler berpeluang menjadi strategi baru untuk meningkatkan efektivitas dan keberhasilan manajemen obesitas. Penelitian ini bertujuan menilai efek dari diet seimbang dan sustainable berbasis aplikasi dibandingkan dengan diet seimbang berbasis aplikasi terhadap resistensi insulin. Uji klinis acak tersamar ganda dilakukan terhadap 56 wanita obesitas usia 19 ndash;59 tahun dengan indeks massa tubuh ge;25 kg/m2 yang bekerja atau belajar atau tinggal di Jakarta Pusat dan/atau Kota Depok. Subjek dibagi secara randomisasi berstrata berdasarkan kelompok usia 0.05] dan perubahan asupan lemak [ -5.8 23.9 vs -6.4 22 , p >0.05] antar kelompok. Meskipun ada pengurangan nilai HOMA-IR pada kelompok intervensi, perbedaan rerata perubahan HOMA-IR antar kelompok tidak berbeda bermakna setelah dilakukan penyesuaian dengan Indeks Massa Tubuh [ -0.87 1.27 vs -0.29 1.21 , p >0.05]. Kesimpulan : Intervensi diet seimbang dan sustainable berbasis aplikasi selama 8 minggu tidak mengurangi nilai HOMA-IR dibandingkan dengan diet seimbang berbasis aplikasi. Penelitian lebih lanjut diharapkan dapat dilakukan dengan periode yang lebih lama atau lebih banyak subjek dalam menerapkan diet yang seimbang dan sustainable.

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Obesity is a major problem today related to more than 3 million deaths because of its complications. A balanced diet with caloric restriction, is known as obesity management, requires a novel ways of producing nutritious foods in a sustainable manner because of the issues of environment changes, food security, and biodiversity. Mobile application is a new strategy to improve the effectiveness and success of obesity management. We examine the effect of a balanced and sustainable dietary mobile application compared to a balance diet application on the change of insulin resistance as a common attribute for obesity and type 2 diabetes. A double blind randomized clinical trial was conducted involving 56 obese women aged 19 59 years with body mass index ge 25 kg m2 working or studying or residing in Central Jakarta and or Depok City. Subjects were selected randomly and stratified based on age group 0,05 and fat intake changes 5.8 23.9 vs 6.4 22 , p 0,05 were observed between groups. Although there was a significant reduction of HOMA IR within intervention group, the difference in the mean reduction of HOMA IR after intervention 0.87 1.27 vs 0.29 1.21 , p 0.05 between group was not significantly different after adjusted by Body Mass Index.Conclusion An 8 week of balanced and sustainable dietary application intervention did not reduce elevated HOMA IR level compared with a balanced diet application. Further research is expected to be performed with longer periode or more subject in applying a balanced and sustainable diet."