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"ABSTRAKKandungan antioksidan pada teh rosela merah, asam askorbat, dapatdikembangkan sebagai inhibitor untuk menghambat laju korosi untuk baja karbonrendah di lingkungan NaCl 3,5%. Metode yang digunakan adalah metodekehilangan berat dengan variasi waktu perendaman (3, 6, 9, 12 hari). Pada semuawaktu perendaman, konsentrasi teh rosela merah yang digunakan adalah 10 gpl,sedangkan penambahan inhibitor teh rosela merah sebanyak 2 ml. Hasil penelitianini dapat ditunjukkan oleh nilai efisiensi yang diperoleh, efisiensi terendah sebesar8% pada waktu pengujian 3 hari, sedangkan efisiensi optimum sebesar 16% padapengujian 9 hari.

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AbstractThe content of antioxidants in red roselle tea, ascorbic acid, can be developed asan inhibitor to inhibit corrosion rate for low carbon steel in 3.5% sodium chloridesolution. The method that used is a method of weight loss with variation ofimmersion time (3, 6, 9, 12 days). In all the immersion time, concentration of redroselle tea that used was 10 gpl, while the addition of inhibitors of red rosella teaas much as 2 ml. The results could be demonstrated by the efficiency valuesobtained, the lowest efficiency of 8% at 3 days of testing, while the optimumefficiency of 16% at 9 days of testing."

"ABSTRAKTeh rosella merah memiliki kandungan antioksidan yang cukup tinggi berupaasam askorbat. Asam askorbat ini mampu untuk menurunkan laju korosi yangterjadi pada baja karbon rendah di lingkungan HCl 1 Molar. Metode kehilanganberat digunakan untuk menguji keefektifan teh hijau sebagai inhibitor denganvariasi waktu pencelupan (3 hari, 6 hari, 9 hari, dan 12 hari). Hasil yangdidapatkan adalah nilai efisiensi tertinggi didapatkan pada variabel 3 hari yaitusebesar 63% dan nilai efisiensi terendah didapatkan pada variabel 12 hari yaitusebesar 41%.

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AbstractRed roselle tea contains a large amount of antioxidant namely ascorbic acid.Ascorbic acid is able to reduce corrosion rate on low carbon steel in HCl 1 M.Weight loss methode is used to test the effectiveness of red roselle tea as aninhibitors with various immersion time (3 days, 6 days, 9 days, and 12 days). Theresult shows that the maximum value was found in 3-days immersion time with63% of efficiency and the minimum value was found in 12-days immersion timewith 47% of efficiency."

"Pengujian ultrasonik, sebagai bagian dari metode evaluasi tak merusak saat ini menjadi sangat penting karena penerapannya tidak hanya digunakan sebagai metode pendeteksian cacat, tetapi lebih jauh digunakan sebagai metode karakterisasi material, seperti untuk prediksi pengukuran ketebalan lapisan pada baja yang terkarburisasi, sehingga pada aplikasinya dapat mencegah terjadinya degradasi material.Penelitian ini bertujuan untuk memprediksi kedalaman difusi baja rendah karbon yang terkarburisasi dengan menggunakan pengujian ultrasonik.Pada penelitian ini dilakukan karburisasi pada sampel menggunakan metode pack carburizing, dengan variabel temperatur dan waktu tahan yang berbeda. Kemudian dilakukan pengujian ultrasonik menggunakan metode water immersion dengan probe berfrekuensi 10 MHz, untuk mengetahui kedalaman difusi masingmasing sampel.Hasil dari penelitian ini menunjukkan bahwa prediksi untuk kedalaman difusi menggunakan pengujian ultrasonik dapat dilakukan, dengan hasil nilai yang tidak jauh berbeda dengan standar untuk kesesuaian kedalaman difusi. Besar penyimpangan rata-rata dari setiap sampel yang diujikan adalah 19.3 %.

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Ultrasonic testing as a part of Non Destructive Evaluation method become very important nowadays, because it?s not only applicable for flaw detection but also can be used for material characteristization method, such as prediction for diffusion thickness of carburized surface layer. By this prediction, the output is for preventing material degradation.The objective of this experiment is to predict diffusion thickness as a result of carburizing for low carbon steel with longitudinal ultrasonic velocity waves.This experiment is performed using nine samples that carburized using parameters with austenitization temperature and holding time. Ultrasonic testing is done by using water immersion method with frequency 10 MHz.The result of this experiment show that the prediction for diffusion thickness using ultrasonic test can be allowed, in which the result is not significantly different if compared to diffusion thickness standard. The average value of deviation for each sampel is 19.3 %."

"Baja HSLA dan baja karbon rendah merupakan jenis baja yang banyak diaplikasikan pada bidang konstruksi maupun otomotif dimana keuletan dan ketangguhan yang baik sangat dibutuhkan. Adanya penambahan sejumlah kecil (0,15%) unsur paduan tertentu pada baja HSLA yang menghasilkan sifat mekanis yang baik melalui penguatan presipitat dan penghalusan butir menyebabkan baja ini lebih unggul dari baja karbon rendah biasa. Penelitian ini dilakukan untuk mempelajari sejauh mana komposisi kimia mempengaruhi morfologi ferit yang terbentuk pada baja HSLA dibandingkan baja karbon rendah yang akan berpengaruh pada sifat mekanis akhir serta ketahanan korosinya. Benda uji yang digunakan yaitu, baja HSLA 0,029% Nb dan baja karbon rendah yang dipanaskan ulang pada temperatur 1200 °C dengan waktu tahan 1 jam dengan pencelupan air.Perlakuan pemanasan ulang sampai pada temperatur 1200 °C dengan waktu tahan 1 jam dengan pencelupan air akan menyebabkan berubahnya morfologi ferit dari baja HSLA maupun baja karbon rendah. Perubahan morfologi dari ferit ini akan menyebabkan sifat mekanis dan ketahanan korosi dari baja HSLA dan baja karbon rendah mengalami perubahan yang antara lain dipengaruhi oleh adanya transformasi fasa serta bertambah besarnya diameter butir ferit. Pemanasan pada temperatur 1200 °C dengan waktu tahan yang cukup lama (1 jam) menyebabkan meningkatnya migrasi atom pada batas butir melalui proses difusi sehingga ukuran butir akan bertambah besar yang nantinya akan mempengaruhi sifat ketahanan korosinya.Perlakuan pemanasan ulang dengan pendinginan yang cepat menyebabkan terbentuknya lath martensit serta struktur widmanstatten ferit pada mikrostruktur baja HSLA. Berbeda dengan baja karbon rendah yang tetap memiliki struktur ferit namun ukuran butirnya tidak seragam pada mikrostrukturnya. Pemanasan ulang menghasilkan ukuran butir ferit yang lebih besar dari sebelumnya serta meningkatkan ketahanan korosi dari baja dengan baja HSLA memiliki ukuran butir ferit yang lebih besar dan ketahanan korosi yang lebih baik dibandingkan dengan baja karbon rendah biasa.

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HSLA steel and low carbon steel has a good ductility and toughness which is needed in constructional and automotive aplication. Additional small number (0,15%) of certain alloy on HSLA steel increasing it mechanical properties, by precipitation strenghtening and grain refinement, to better than normal low carbon steel. This research is done to study the comparison of influence chemical composition to ferrite morphology that occur after isothermal process on HSLA steel and low carbon steel and their corrosion resistant. Sample is HSLA 0,029% Nb and low carbon steel (0,15% C), reheating at isothermal temperature 1200 °C, with about 1 hour, with water quenching.Reheating at isothermal temperature 1200 °C, with holding time about 1 hour, with direct water quenching cause the transformation of ferrite morphology of both HSLA steel and low carbon steel that influence the change of mechanical and corrosion properties. The change of mechanical and corrosion properties influenced by increasing the ferrite grain size and also the phase transformation of steel. High temperature of reheat (1200 °C) and long holding time (1 hour) enhance the atom migration on grain boundary so that the austenit grain size growing larger and as result the ferrite grain size is larger.High reheating temperature with rapid cooling cause the lath martensite and widmanstatten ferrite formed on microstructure of HSLA steel. On the other hand, there is no phase transformation changing on low carbon steel, it still has ferrite with rough grain size. Reheating process will increase both the ferrite grain size and corrosion resistant of steel with HSLA steel has larger the ferrite grain size and better corrosion resistant than low carbon steel."

"To solve the global climate change problem, countries require more than efforts at locallevel: multilateral cooperation and climate policy integration are essential for realizing awide-area low-carbon society. Realizing a low-carbon society is not a simple action that addresses global warming while ignoring the quality of human life, but is a process to achieveharmonious sustainable development of economy, environment and society while solving theproblem of global warming simultaneously. According to the principle of “Common but Differentiated Responsibilities", China should stick to the consistent pathway towards emission reduction. Energy saving, followed by fuel transformation and renewable energy utilization, is the most efficient technology China will promote to achieve the emission reduction, In addition, Carbon Capture and Storage (CCS) technologies will play an important role after 2050. China's CO2 emissions are likely to peak around 2040 (550pprn) or even earlier in about 2030 (450ppn1) with great efforts. No single energy source is going to be the solution to global warming Development of alternative power sources is the only way towards sustainable development. As a developing country, China's pathway to a lowcarbon economy is absolutely a n0-regret approach with recognizing the uncertainty of climate change Nevertheless, the low-carbon economy is just one of the necessary conditions for achieving sustainable development. In this study, firstly we discussed the future direction and technology strategies for realizing a low-carbon society in the Post-Kyoto climate policy framework. "

"It is well known that the extensive emission of greenhouse gases(GHG) such asCO2 gas and freon gas during a long period up to the present society after the industri-al revolution in the 18th century is a fundamental reason causing the global warmingand the climate change on our globe as reported in a lot of references”. In such a cir-cumstance, the average temperature during an entire year at the surface of the globehas been elevated about ldeg.C comparing the corresponding temperature at the in-dustrial revolution. Thus, mitigation or reduction of the global warming is one of themost important subject to keep the continuous development of human beings.On the other hand, drying up of energy resources as fossil fuels is another seriousproblem to realize the sustainable development of our industrial society and our dailylives. Nuclear power would be a clean energy, since the fossil fuel is not used and CO2gas is not emitted during the generation of the power. "

"In recent years, as a supplement for conventional large-scale power generation system,gas distributed generation has got much comprehensive attention. This study reviews the cur-rent status, incentive policies and barriers of gas distributed generation in Shanghai. Currently,the gas distributed energy development in Shanghai is facing grim situations: on the one hand,most of the prime movers are imported from abroad with relaitvely high initial cost, and thenatural gas price increases gradually, which lead to the poor economic performance; on theother hand, the relevant institution, mechanism and policy frameworks are imperfect, makinggas distributed energy system difficult to fully enjoy its energy saving advantages. However,considering the huge market potential in Shanghai and successful experiences in some foreigncountries, it is believed that gas distributed generation will be paid more and more attention,and support the low-carbon transition of the electric power industry in Shanghai."

"Many emerging economies are on the front line of the devastating impacts of global warming such as desertification and extreme weather events, but, for historical and political reasons, they follow ambitious growth targets with seemingly little concern for climate change and environmental degradation. Focusing on the case of Turkey, this book investigates the economic impacts of possible climate change policies to help meet the required mitigation targets and transition to a low carbon economy. In order to reach net-zero targets by 2050 in compliance with the Paris Agreement, Turkey must introduce policies that promote low carbon investments, green jobs and low carbon employment more broadly. This book explores the empirical evidence on the effectiveness of a carbon pricing mechanism by developing an econometric vector autoregression (VAR) model to analyse key data sets. This time series analysis provides insights on a macro level, dealing with aggregate data in which the role and complexity of micro interferences disappear, allowing for the discovery of patterns and changes over time. Thus, the book contributes to the literature on methodology by arguing that time series analysis is one of the best-fitting approaches to estimate possible impacts of climate change policies on an economy. Additionally, the results of the model are compared and contrasted with similar data from other emerging economies to identify potential common policy solutions between countries at a similar stage of development. This book is vital reading for researchers interested in climate policy, the economics of climate change and environmental economics."

"Cultured sporophytic thalli of Undaria pinnatifida were collected at different periods of the year from Okkirai Bay, northeastern Japan

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