Hasil Pencarian  ::  Simpan CSV :: Kembali

"Kopolimerisasi onggok-polivinil alkohol (PVA)-akrilamida (AAm) dibuat dengan teknik iradiasi sinar gamma. Campuran bahan-bahan tersebut dibuat menjadi suatu kopolimer yang ramah lingkungan bersifat biodegradable sehingga dapat diaplikasikan dalam bidang pertanian sebagai bahan untuk modifikasi pupuk fosfat yang memiliki sifat pelepasan lambat. Kopolimer dibuat dengan jumlah onggok tetap, serta volume PVA 10% w/v dan akrilamida 3% w/v divariasikan. Selain itu, variasi dosis iradiasi (5, 10, 15, dan 20 kGy) dilakukan pada pembuatan kopolimer. Pada penelitian ini diperoleh kopolimer yang paling baik untuk digunakan sebagai bahan modifikasi pupuk fosfat adalah sampel (I). Sampel (I) merupakan kopolimer onggok-polivinil alkohol-akrilamida dengan komposisi 3 gram onggok, 45 mL PVA 10% w/v, dan 105 mL Akrilamida 3% w/v. Terjadinya kopolimerisasi onggok-PVA-akrilamida pada sampel (I) ditunjukan oleh hasil karakterisasi FTIR. Pengaruh penambahan onggok terhadap kestabilan termal dan terbentuknya pori pada kopolimer sampel (I) di tunjukan oleh hasil karakterisasi TGA dan SEM. Pengamatan dan pengujian terhadap nilai persen fraksi gel, rasio swelling, dan persen pelepasan fosfat pada kopolimer sampel (I) diperoleh hasil sebesar 48.71%, 321.63 %, 18.13%. Pengukuran sifat pelepasan lambat dilakukan dengan metode absorbsi-desorbsi. Dalam penelitian ini terlihat bahwa sifat kopolimer dipengaruhi oleh komposisi PVA dan akrilamida dan dosis iradiasi.

---

Copolymerization of tapioca waste-polyvinyl alcohol (PVA)-acrylamide was made with gamma irradiation techniques. Mixtures of these materials made into an copolymer that have environmentally-friendly with biodegradable properties so that it can be applied in agriculture as a material for the modification of phosphate fertilizers that have slow release properties. Copolymer was made with fixed amount of tapioca waste and the volume of PVA 10% w/v and acrylamide 3% w/v was varied. In addition, the variation of irradiation dose (5, 10, 15, and 20 kGy) was done on making of the copolymer. In this study was obtained the best copolymer to be used as material for the modification of phosphate fertilizers was sample (I). Sample (I) was the copolymer of tapioca waste-polyvinyl alcohol-acrylamide with 3 gram tapioca waste, 45 mL PVA 10% w/v, and 105 mL acrylamide 3% w/v as the composition. The occurrence of copolymerization tapioca waste-PVA-acrylamide on sample (I) was shown by the results of FTIR characterization. Effect of tapioca waste on the thermal stability and the formation of pores in the copolymer sample (I) was shown by the results of TGA and SEM characterization. Observation and testing the yield of percent gel fraction, swelling ratio, and percent release of phosphate in the copolymer sample (I) was obtained respectively 48.71%, 321.63 %, 18:13%. Measurement of slow release properties was done by absorption-desorption methode. In this study shows that the properties of copolymer is influenced by the composition of the PVA and acrylamide and irradiation dose."

"Telah dilakukan sintesis hidrogel metilselulosa dari 5 tipe berat molekul menggunakan radiasi berkas elektron pada dosis 10 kGy hingga 100 kGy. Film hidrogel dengan ukuran 16cm x 16 cm x 1,2mm dilakukan pengamatan terhadap sifat fisik dan mekanik yang meliputi, persen pengembangan, fraksi gel, kekuatan tarik dan perpanjangan lurus. Pengukuran dengan viscometer ubbelohde, diperoleh berat molekul (Mv)m metilselulosa berurutan dari rendah ke tinggi adalah sebagai SM-4"

"The process of irradiation with gamma rays on agricultural products can rise to ozone. Ozone is harmful to the environment because the smell is strong. Ozone must be removed from the room by force of radiation, for it required a tool that can suck to be discharged into the atmosphere...."

"Keberadaan limbah antibiotik di berbagai sumber air menimbulkan bahaya lingkungan yang besar, karena limbah tersebut tetap utuh dan tahan terhadap dekomposisi, sehingga menimbulkan tantangan bagi ekosistem. Penelitian ini bertujuan untuk mengatasi masalah ini dengan berfokus pada penetapan muatan optimal g-C3N4 dalam komposit g-C3N4-TiO2. g-C3N4 diproduksi dari beberapa prekursor seperti melamin, disiandiamida, dan urea. Tujuan utama komposit baru ini adalah berfungsi sebagai fotokatalis yang sangat efisien untuk degradasi ciprofloksasin di bawah pengaruh pencahayaan yang berbeda. Fotokatalis yang dihasilkan akan dikarakterisasi secara menyeluruh menggunakan berbagai teknik termasuk XRD, UV-Vis DRS, SEM, dan FTIR. Degradasi ciprofloksasin akan dipantau secara cermat dengan mengumpulkan sampel larutan secara berkala dan melakukan analisis menyeluruh menggunakan spektrofotometri UV-Vis. Uji degradasi akan dilakukan menggunakan reaktor foto yang dibangun secara khusus, yang akan memanfaatkan iradiasi internal dari lampu UV 20 W dan lampu tampak 23 W. Metode yang digunakan untuk percobaan ini adalah kalsinasi untuk sintesis g-C3N4, dan impregnasi untuk pencampuran komposit. Setelah melakukan percobaan, jenis komposit yang paling efektif ditemukan yaitu (5)U-CN- TiO2, dengan laju degradasi 82%, yaitu 29% lebih besar dari TiO2 murni di bawah Iradiasi sinar UV dan laju degradasi 31%, yaitu 15% lebih besar dari TiO2 murni di bawah cahaya tampak. Oleh karena itu, penambahan g-C3N4 ke TiO2 dapat meningkatkan laju degradasi fotokatalitik.

---

The presence of antibiotic waste in different water sources poses a substantial environmental hazard, as it remains intact and resistant to decomposition, hence posing a challenge to the ecosystem. This study aims to address this problem by focusing on establishing the optimal loading of g-C3N4 within g-C3N4-TiO2 composite. The g-C3N4 is produced from several precursors such as melamine, dicyandiamide, and urea. The primary objective of these new composites is to function as exceptionally efficient photocatalysts for the degradation of ciprofloxacin under the influence of different lighting. The generated photocatalysts will be thoroughly characterized using a range of techniques including XRD, UV-Vis DRS, SEM, and FTIR. The degradation of ciprofloxacin will be carefully monitored by periodically collecting samples of the solution and doing thorough analysis using UV-Vis spectrophotometry. The degradation trials will be carried out using a specifically built photo reactor, which will utilize internal irradiation from a 20 W UV light and 23 W visible light. The methods used for this experiment were calcination for the synthesis of g-C3N4, and impregnation for mixing the composite. After conducting the experiment, the most effective type of composite was discovered to be (5)U-CN-TiO2, with a degradation rate of 82%, which is 29% greater than pure TiO2 under UV light Irradiation and 31% degradation rate, which is 15% greater than purê TiO2 under visible light. Therefore, the addition of g-C3N4 to TiO2 can increase the photocatalytic degradation rate."

"Salah satu komponen nutrisi utama pada beras adalah karbohidrat. Karbohidrat pada beras banyak tersimpan dalam bentuk pati. Pati dibagi menjadi dua fraksi, yakni amilosa dan amilopektin. Pati beras dapat dimodifikasi dengan berbagai cara untuk mendapat sifat baru yang lebih dikehendaki. Modifikasi pati beras dapat dilakukan dengan metode fisika salah satunya dengan sinar gama. Sinar gama merupakan isotop radioaktif berupa kobal-60 atau cesium-137 yang akan mengemisikan energi tinggi untuk menginduksi perubahan pada struktur pati dengan memfragmentasi ikatan glikosida pati. Pada penelitian ini sebanyak dua belas varietas beras organik dan nonorganik (Pandan Wangi, IR64, Rojolele, IR42, C4, dan Cisokan) dianalisis kandungan amilosanya setelah diberikan iradiasi sinar gama dengan variasi dosis 2, 5, 10, 20, dan 30 kGy. Pemberian iradiasi sinar gama menaikkan kadar amilosa pada varietas Pandan Wangi nonorganik, IR64 nonorganik, Rojolele nonorganik, IR42 nonorganik, C4 nonorganik, dan Cisokan nonorganik. Pemberian iradiasi sinar gama akan menurunkan kadar amilosa pada varietas Pandan Wangi organik, IR64 organik, Rojolele organik, IR42 organik, C4 organik, dan Cisokan organik. Berdasarkan uji lanjut Tukey ANAVA dua arah, dosis iradiasi sinar gama yang paling berpengaruh untuk mengubah kadar amilosa adalah dosis 10 kGy.

---

One of the main nutrition component in rice is carbohydrate. Carbohydrate in rice is storaged well in the form of starch. Starch itself contains of two fraction, amylose and amylopectin. With certain method, rice's starch could be modified to obtain the desired property. Rice's starch modification could be done with gamma ray irradiation. Gamma ray is the radioactive isotope which could be obtained by the energy emitted by either cobalt-60 or cesium-137 that will induced the starch structural change by the manner of fragmentate the starch’s glycoside bond. The test used the rice from twelve rice variety from organic and non-organic rice (Pandan Wangi, IR64, Rojolele, IR42, C4, and Cisokan), the assay performed after the administration of 2, 5, 10, 20, and 30 kGy doses. The gamma ray irradiation dose that administered to those varieties downgraded the organic Pandan Wangi, IR64, Rojolele, IR42, C4, and Cisokan rice amylose content while upgraded the non-organic Pandan Wangi, IR64, Rojolele, IR42, C4, and Cisokan rice amylose content. According to the post-hoc test from two-way ANAVA, 10 kGy gamma-ray dose was the most affect to altered the amylose content."

"Indonesian Journal of Dentistry 2006; Edisi Khusus KPPIKG XIV: 198-201Radiotherapy plays an important role in the management of head and neck carcinoma therapy. The radiation dose range from 40-70Gy, depends on the severity and location of the malignancy. Many patientsexperience an increased dental caries or sensitivity occurence following radiotherapy. The objective of this study is to analyze the enamel micro-structure changes after irradiation. Nine polished enamel slabs were prepared from impacted 3rd molars. The slabs were flushed in non-ionic distilled water and dried by using air spray and divided into 3 groups, the control, 20Gy and 40Gy irradiation group. lrradiations were performed from Co60 using Gammacell-220E, with duration variables to produce the irradiation doses of 20 and 40Gy. Philips PW370-XRD was used to examine specimen microstructure changes after irradiation. I-way ANOVA was used for statistics analyze. lt was revealed that grain size after 40Gy irradiation was 66.29±2.7 nm, andafter 20 Gy was 51.64±15.8 whilst 43.95±11.1 nm for the control group. The micro-strain deviation of the 40Gy group was 0.594±0.15 N/m, and 0.45±0.26 N/m for the 20Gy group, and 0.378±0.27 N/m for control group. Statistic analysis showed significant grain size differences between 40Gy compared to both 20Gy and control group, but not between 40Gy compared to the control group. Similarly, there were micro-strain differences between 40Gy compared to 20Gy and control groups, but not between 20Gy compare to control group. It was concluded that irradiation with 40Gy caused elevation of the enamel microstrain and apatite grain size. Elevation of the enamel microstrain could lead to enamel crack and gave hypersensitive sensation."

"Telah dilakukan penelitian untuk mempelajari pengaruhiradiasi sinar gamma pada karakteristika kimia dan fisika vitamin D, minyak jagung dan campuran keduanya dengan dosis radiasi 0,10,20 dan 30 kGy dan penyimpanan 0,1,2 dan 3 bulan. Penyimpanan untuk minyak jagung dilaksanakan pada suhu kamar (29 ± 2 0C), sedang untuk vitamin D dan campurannya disimpan ditempat yang sejuk (± 15°C).Parameter yang diuji untuk minyak jagung meliputi bilangan asam, bilangan penyabunan, bilangan iod, bobot jenis, indeks bias, metil ester asam lemak dengan kromatografi Cairan-gas, kadar vitamin D . dengan spektrofotometer, titik lebur vitamin D dengan " Differential Thermal Analyzer " kestabilan vitamin D dan campurannya dengan kromatograf I cairan- cairan tekanan tinggi.Hasil pengujian menunjukkan bahwa bilangan iod, bobotjenis, indeks bias dan metil ester asazu lemak dan minyak jagung tidak dipengaruhi.dosis radiasi dan penyimpanan. Iradiasi sampai 30 kGy memberikan pengaruh terhadap bilangan asam minyak jagung dan menurunkan kestabilan camnpuran. Penyimpanan member ikan pengaruh terhadap b ilangan penyabunan dan bilangan asam minyak jagung. Titik lebur, kadar dan kestabilan vitamin D menurun karena iradiasi sampai 30kGy dan penyimpanan saiapai 3 bulan.

---

Studies on effect of irradiation by gamma rays on

chemical and physical characteristics of vitamine D, corn

oil and their mixture with radiation dose 0,10,20.and 30 kGy

respectively and storage for 0,1,2 and 3 months have been

done. Corn oil was stored at room temperature (29 ± 2°C)

while vitamine D and the mixture were in a cool place

(.± 15°C).

The parameter studied were acid value, saponification

value, iod value, 'density, refraction index, fatty acid metil

ester of corn oil with Gas Liquid Chromatography; vitamine

•D assays with Spectrophotometre; melting 'point of vitamine

D with Differential Thermal Analyzer where stability

of vitamine D and the mixture by High Pressure Liquid Chromatography.

The results obtained, didn't show any influence of

radiation dose and storage periode towards iod value, density,

refraction index and fatty acid meti1 ester of corn oil.

Irradiation dose up to 30 kGy affected the acid value of

corn oil and decreased the mixture stability, while storage

periode changed saponification and acid value of corn oil.

Irradiation dose up to 30 kGy and storage until 3 months reduced

melting point, stability and concentration of vitamine

D."

"Magnesium-Hidroksiapatit (MgHA) disintesis dengan mensubstitusi Magnesium (Mg), yang berperan dalam metabolisme tulang, pada Hidroksiapatit (HA), yaitu salah satu komponen utama dari tulang. Penelitian ini bertujuan untuk mensintesis nano-powder MgHA melalui iradiasi gelombang mikro, dan mengetahui pengaruh dari daya dan waktu iradiasi gelombang mikro terhadap karakteristik MgHA. Sintesis dilakukan dengan mencampurkan larutan diammonium hidrogen fosfat dan larutan magnesium hidroksida ke dalam larutan kalsium hidroksida. Larutan yang telah tercampur diiradiasi dengan gelombang mikro, dengan variasi daya dan waktu iradiasi. Parameter kisi, kristalinitas, ukuran kristalit, gugus fungsi, morfologi, ukuran partikel, dan komposisi MgHA ditentukan dengan menggunakan beberapa metode karakterisasi yaitu; x-ray diffraction (XRD), fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), dan energy dispersive x-ray (EDX). Pola XRD menunjukkan bahwa seiring dengan kenaikan daya dan waktu iradiasi, parameter kisi a dan c, indeks kristalinitas dan ukuran kristalit MgHA tereduksi. Hasil FTIR menunjukkan terdapat ikatan antara Mg2+ dengan gugus hidroksil pada daya dan waktu iradiasi maksimum. Hasil SEM dan EDX menunjukkan substitusi Mg2+ mengakibatkan aglomerasi pada partikel dan Ca/P yang dimiliki oleh MgHA kurang dari 1.67, menunjukkan bahwa sebagian Ca2+ telah lepas dari struktur apatit. Penelitian ini menunjukkan daya yang tinggi dan waktu iradiasi yang lebih lama lebih efektif dalam melakukan sintesis MgHA.

---

Magnesium-Hydroxyapatite (MgHA) is synthesized by substituting magnesium (Mg) into hydroxyapatite (HA). The studys aim was to synthesize MgHA nano-powder via microwave irradiation and determine the effects of the microwave irradiations power and irradiation time variation on the synthesis of the MgHA crystal. The synthesis of MgHA was done by titrating solutions of diammonium hydrogen phosphate and magnesium hydroxide into a solution of calcium hydroxide. The microwave irradiation was done with variations of irradiation power and time. The phase composition, functional groups, morphology, particle size, and the element composition of the MgHA powder was evaluated using the following characterization method; XRD, FTIR, and SEM-EDX.

The XRD patterns show that lattice parameters a and c, crystallinity index, and crystallite size of MgHA decreases as the irradiation time increases. The FTIR results show that a stretching mode is caused by the bonding of Mg2+ and the hydroxyl group. The SEM and EDX results shows that the substitution of Mg2+ causes the particles to agglomerate and the Ca/P value of MgHA was determined to be lesser than 1.67, showing that some Ca2+ was released from the apatite. The results show that higher irradiation power and longer irradiation time is more effective in MgHA synthesis."