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Abstrak :
Penelitian ini bertujuan untuk menghasilkan rangkaian alat dengan teknik jet bubble yang dapat digunakan untuk proses absorpsi kimiawi gas CO2 dari gas umpan berkandungan CO2 50%mol, mendapatkan kurva penurunan konsentrasi CO2 terhadap waktu untuk kondisi variasi ukuran gelembung 0,62, 1,25, dan 7,09 mm dan juga variasi konsentrasi absorben KOH 10, 15, dan 20%b, serta untuk memperoleh hasil absorpsi kimiawi CO2 dengan metode batch bertahap, dimana larutan absorben hasil absorpsi batch pertama digunakan sebagai absorben untuk absorpsi batch kedua dengan komposisi gas umpan sama yaitu 50%mol. Absorpsi dengan gelembung berdiameter 0,62 mm menurunkan konsentrasi CO2 menjadi 9,4%mol, 1,25 mm menjadi 10,5%mol, dan 7,09 mm menjadi 15,9%mol, sehingga yang terbaik adalah ukuran gelembung paling kecil karena meningkatkan nilai luas kontak dan koefisien transfer massa. Absorpsi dengan KOH 10%b menurunkan konsentrasi CO2 menjadi 9,4%mol, 15%b menjadi 15,6%mol, dan 20%b menjadi 13,9%mol. Sehingga yang terbaik adalah konsentrasi KOH 10%b karena K2CO3, yang dihasilkan dari reaksi kesetimbangan dan berfungsi sebagai senyawa penyerap CO2, hadir pada pH lebih dari 10 serta paling larut dalam KOH konsentrasi rendah. Metode batch bertahap membuktikan bahwa terbentuk K2CO3 pada absorpsi batch 1, yang menjadi absorben CO2 pada absorpsi batch 2, dengan kemampuan menurunkan konsentrasi CO2 dari 50%mol hingga 11,2%mol. ......This study aimed to produce equipment series with jet bubble technique that can be used for CO2 gas chemical absorption from 50%mole CO2 feed gas, obtain a CO2 concentration reduction curve for bubble size variation of 0.62, 1.25, and 7.09 mm, and KOH absorbent concentration variation of 10, 15, and 20%w, and also to obtain CO2 chemical absorption result with serial batch method, in which absorbent solution resulted from first batch absorption was used as absorbent for second batch absorption with the same feed gas composition. Absorption with 0.62 mm diameter bubble reduced CO2 concentration to 9.4%mole, 1.25 mm to 10.5%mole, and 7.09 mm to 15.9%mole, so the best is the smallest bubble size because contact area and mass transfer coefficient was enhanced. Absorption with 10%w KOH reduced CO2 concentration to 9.4%mole, 15%w to 15.6%mole, and 20%w to 13.9%mole. So 10%w KOH is the best because K2CO3, that was produced from equilibrium reaction and functioned as CO2 absorbent, presented in pH above 10 and most soluble in lower KOH concentration. Serial batch method proved that K2CO3 was formed on batch 1 absorption, which became CO2 absorbent in batch 2 with CO2 concentration reduction capability from 50%mole to 11.2%mole.

Abstrak :
This book provides a comprehensive view of the most commonly used photochemical and photophysical techniques and their applications to the study of supramolecular systems. Optical inputs are extremely powerful in the study of nanostructures since they can be used both to “read” the state of the system and to provide it energy to work. After a brief introduction to the realm of photochemistry, electronically excited state formation and the different pathways of excited state deactivation, the book focuses on the theoretical basis and the practical aspects related to the most widely used photophysical and photochemical techniques, from absorption to time-resolved emission techniques with polarized light. Each chapter illustrates an example of the application of that particular technique to the study of a supramolecular system. This book also offers technical and operative details useful in the laboratory.

Abstrak :
Strontium hexaferrite dengan komposisi nominal Sr0.6Fe,-<,..,jMn,TiyO, (x =0, y=; x = 0.4, y= 0.6; x = 0.5, y = 0.5; x = 0.6, y =0.4) disintesa dengan reaksi keadaan padat. Empat komponen serbnk BaCO,, SrCO,, Fe,O,, MnCO,, dan TiO, dicampur menggunakan High Energy Milling selama 10 jam dan disinterring pada 1050'C dalam tekanan atrnosfer selama 15 jam dan pendinginan eli tungku pemanas. X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), vibrating sample magnetometer (VSM) dan network analyzer digunakan untuk analisa struktur, sifat elektomagnetik dan penyerapan gelombang. Hasil memperlihatkan bahwa identifikasi fasa dengan penghalusan pola difrkasi XRD diperoleh fasa tunggal untuk substitusi Mn-Ti terhadap Sr0.6Fe,o, dengan x ~ y dan multi fasa terbentuk untnk x " y. Analsis mikrostrnktur dengan SEM menunjukkan variasi partikel adalah 2 - 5 um. Evaluasi terhadap karakteristik magnetik mengindikasikan bahwa terjadi penurunan koersifitas dengan kenaikan substitusi ion Mn2+ dan Ti4+ tetapi penurunan yang signifikan diperoleh terhadap saturasi magntetisasi pada substitusi Mn dan Ti dengan x :t: y. Penelitian saat ini menunjukkan penyerapan gelombang, reflection dan transmission dan juga reflection loss pada rentang frekuensi 7-16 GHz. Dilaporkan juga performansi penyerapan pada substitusi Mn dan Tipada strontium hexaferrite. ......Strontium hexaferrite with nominal compositions Sr0.6Fe,-{"':Y~xTiy03 (x ~ 0, y o=Q; x ~ 0.4, y ~ 0.6; x ~ 0.5, y ~ 0.5; x ~0.6, y ~ 0.4) have been synthesized by solid state reaction. The four components powder were BaCO,, S!CO,, Fe,O,, MnCO,, and Ti02 mixed with High Energy Milling for 10 hours and sintered at I 050'C in the air at atmosphere pressure for 15 hour and furnace cooling. X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), resonance vibrating sample magnetometer (R· VSM) and vector network analyzer were used to analyze its structure, electromagnetic and microwave absorption properties. The result showed that, phase identification by refinement results ofXRD pattern confirmed single phase was obtained for Mn-Ti substituted Sr0.6Fe20, with x ~ y and multiphase formed for x" y. The microstructure analyses by SEM showed that the varied particle sizes of 2 -- 5 ~-tm. Evaluation on the magnetic characteristic indicated that coercivity decreased as the number ofMn2"~" and Ti +ions increased but significant decrease in saturation magnetization obtained for Mn and Ti substitution with x ::1:- y. Present investigation demonstrates that microwave absorber. reflection and transmission as well as reflection loss in the frequency range 7-16 GHz were derived Absorption performance ofMn and Ti substituted strontium hexaferrite are also reported.