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"Bone mineral content at old age is dependent upon the peak bone mass achieved in youth and subsequent adult bone loss (Matkovic, 1992). Adequate calcium consumption during childhood is beneficial for the acquisition of peak bone mass and density. It is therefore, calcium has been considered to play important role in the pathogenesis of osteoporosis (NIH, 1994), and osteoporosis has been described as a pediatric disease that manifests itself in old age (Lysen and Walker, 1997). If children fail to take in enough calcium, they are more likely to develop osteoporosis later in life (Insel et al., 2002). Nevertheless, calcium is one of the nutrients that most likely to be low or deficient in children's diets (Krause's, 2000). Recently, calcium has been suspected to have a positive effect in preventing some disorders, including diarrhea. Bovee et al., (2003) indicated that low calcium intake has been shown to impair host resistance to food-borne intestinal infections. Because of childhood morbidity and mortality due to infectious diarrhea is very high in developing countries, adequate dietary calcium intakes of the children will likely improve their bone as well as intestinal health (Bovee et al., 2003). Dairy products are always regarded as primary source of calcium. It is difficult to meet the RDA for calcium without milk or milk products (Krause, 1992). Unfortunately, the general Indonesian population does not commonly consume milk.

The results of 1997 national survey on households' food consumption pattern across provinces in Indonesia reveal that milk consumption was zero, or milk product was never consumed in the last three months at the time of survey (Sumarno at al., 1997). In line with the 1997 national survey, Ariani et al., (1997) reported that the level of milk consumption was lower than that of other animal products across the provinces in Indonesia, and in general, milk consumption of Indonesian population was below the standard of adequacy of milk consumption according to Widyakarya National Pangan dan Gizi 1998 (4.6 kg/cap/year). The above facts indicate that many Indonesians may consume calcium-deficient diet."

"Gemuk bio overbased kalsium sulfonat kompleks dibuat dari minyak kelapa sawit terepoksidasi yang digunakan sebagai base oil dan overbased kalsium sulfonat kompleks sebagai thickening agent. Thickening agent yang digunakan dalam penelitian ini adalah kalsium sulfonat, kalsium karbonat, dan kalsium hidroksida sebagai sabun utama (overbased kalsium sulfonat) serta kalsium oleat terepoksidasi dan kalsium asetat (kalsium oleat-asetat) sebagai pengompleksnya. Perbandingan campuran kalsium sulfonat-karbonat-hidroksida sebagai overbased kalsium sulfonat dengan kalsium oleat terepoksidasi-asetat sebagai pengompleks yaitu 5% : 95% dan 50% : 50%. Gemuk ini dihasilkan dari proses saponifikasi yang menggunakan reactor batch tertutup, dilanjutkan dengan proses pendinginan, dan terakhir proses homogenisasi. Pengaruh variasi komposisi pengompleks sebagai thickener dapat dilihat dari pengujian karakteristik gemuk bio yang terdiri dari uji sifat fisik dan kimia seperti uji tampilan gemuk, uji mulur, uji penetrasi, dan uji dropping point, serta uji four ball untuk mengetahui performa dari gemuk. Hasil terbaik yang didapat pada perbandingan overbased kalsium sulfonat : kalsium oleat-asetat sebesar 5% : 95% yaitu gemuk dengan komposisi thickening agent 35% dengan rentang penarikan mulur 9.5 cm, tingkat konsistensi NLGI #2, nilai dropping point 250˚C, dan nilai keausan sebesar 0.2 mg. Untuk gemuk dengan perbandingan overbased kalsium sulfonat : kalsium oleat-asetat sebesar 50% : 50% yaitu gemuk dengan komposisi thickening agent 50% dengan rentang penarikan mulur 7 cm, tingkat konsistensi NLGI #2, nilai dropping point 269˚C, dan nilai keausan sebesar 0.3 mg.

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Overbased calcium sulfonate grease bio complex is made from palm oil epoxidized as a base oil and overbased calcium sulfonate complex as a thickening agent. Thickening agent used in this study is calcium sulfonate, calcium carbonate, and calcium hydroxide as a major soap (overbased calcium sulfonate) and epoxidized oleic calcium and acetate calcium (oleic-acetate calcium) as complexing. Comparison of a mixture of calcium sulfonate-carbonate-hydroxide as overbased calcium sulfonate with epoxidized oleic calcium-acetate calcium as complexing is 5% : 95% and 50% : 50%.

This grease is produced from the saponification process which uses a closed batch reactor, followed by a cooling process, and the final homogenization process. Effect of complexing composition variations as a thickener can be seen from the test characteristics of bio grease, consisting of physical and chemical properties test such as a test to see grease, creep testing, penetration testing, dropping point testing, and four ball test to determine the performance of the grease.

The best results were obtained in comparison overbased calcium sulfonate : oleic calcium-acetate at 5% : 95% are grease with thickening agent composition of 35% with a range of 9.5 cm, the level of consistency of NLGI # 2, the value of dropping point 250˚C, and value of wear 0.2 mg. For the grease by comparison overbased calcium sulfonate : oleic calcium-acetate at 50% : 50% are grease with thickening agent composition of 50% with a range of 7 cm, the level of consistency of NLGI # 2, the value of dropping point 269˚C, and anti-wear value is 0.3 mg."

"ABSTRAKPada pembuatan gemuk bio ini digunakan Kalsium karbonat atau CaCO3 berukuran submikro-mikro sebagai aditif padat untuk meningkatkan sifat antiwear dari gemuk bio yang dihasilkan dengan NLGI #2. Penelitian ini diawali dengan pengepoksidasian minyak sawit pada suhu 65 ˚C; sintesis gemuk bio yang meliputi proses pengadukan, pemanasan, dan saponifikasi pada suhu maksimum 165 ˚C; homogenisasi pada suhu 70 ˚C; serta pengujian karakteristik dan performa gemuk bio yang meliputi uji konsistensi, uji dropping point, serta four ball test untuk menguji sifat antiwear gemuk bio dengan kecepatan putaran sebesar 1150 rpm. Adapun variabel yang terdapat pada penelitian ini yaitu waktu dan suhu selama proses sebagai variabel control; komposisi aditif CaCO3 sebagai variabel bebas; ukuran partikel CaCO3, komposisi base oil, thickener agent, dan BHT serta hasil uji karakteristik sebagai variabel terikat. Hasil yang didapat yaitu gemuk bio NLGI #2 dengan dropping point pada suhu 301 ˚- 317 ˚C. Untuk hasil pengujian antiwear terbaik didapat pada gemuk bio dengan penambahan 3,5% CaCO3 submikro-mikro dengan pengurangan massa ball bearing sebesar 0,7 mg, sementara pada gemuk bio dengan 0% CaCO3 pengurangan tersebut sebesar 250 mg.

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ABSTRACTIn the making of this bio grease, calcium carbonate or CaCO3 in submicro-micro size is used as a solid additive to increase its antiwear properties. To start the research, the epoxidation of palm oil in 65 ˚C is done first; and then synthesizing of bio grease which consists of mixing, heating, and saponification with maximum temperature at 165 ˚C; homogenization in 70 ˚C; and characterization tests that includes the concistency test, dropping point test, and four ball test. The variable contained in this research are time and temperature as control variable; composition of CaCO3 as independent variable; CaCO3 particle size, composition of base oil, thickener agent, BHT, and the result of characterization test as dependent variable. To start the research, the epoxidation of palm oil is done first, and then synthesizing of bio grease, and characterization testing that includes the elasticity test, concistency test, dropping point test, and four ball test in 1150 rpm. The results of this research are, the bio grease has NLGI #2 with 301 ˚- 317 ˚C in dropping point test. For the antiwear test, the best result is possessed by bio grease with 3.5% of CaCO3 addition with reduction of mass ball bearing as much as 0.7 mg, meanwhile in bio grease with 0% of CaCO3 gave 250 mg reduction of mass ball bearing."

"ABSTRAKLatar belakang : Penggunaan konsentrasi kalsium dialisat ([Ca-D]) masih kontroversi. Di Indonesia masih digunakan [Ca-D] yang berbeda-beda antara 1,25 mmol/L ? 1,85 mmol/L. Studi DOPPS mendapatkan kegagalan dalam pencapaian kadar kalsium (Ca), fosfat (PO4), produk CaxP dan hormon paratiroid (HPT) sesuai yang ditargetkan K/DOQI dan semua penyebab risiko mortalitas secara signifikan berhubungan dengan tingginya [Ca]-D

Tujuan : Mengetahui perbedaan kadar Ca darah, PO4, HPT dan kalsifikasi vaskular pada penggunaan [Ca]-D tinggi dan rendah. Metode : Penelitian adalah studi potong lintang analitik dilakukan di Unit Hemodialisis Divisi Ginjal-Hipertensi RS Cipto Mangunkusumo, Jumlah subyek 46 orang. Dua puluh tiga pasien menggunakan [Ca]-D rendah (1,25 mmol/L) dan 23 pasien menggunakan [Ca]-D tinggi (1,85 mmol/L). Penelitian dilakukan Oktober 2013 ? Mei 2014. Analisis statistik dengan uji Mann Whitney dan uji Chi square. Menggunakan SPSS 20.0.Hasil : Sebanyak 46 pasien, terdiri dari 25 laki-laki dan 21 perempuan, dengan rerata usia 50,87 + 12,74 tahun. Lama HD 45,50 (6-168 bulan). Subyek penelitian yang mencapai target kontrol metabolisme sesuai panduan K/DOQI 2002 pada [Ca]-D rendah : Ca terkoreksi, PO4, produk Ca xPO4, dan HPT yang mencapai target sebanyak 8(34,8%), 10(43,5%), 15(65,2%) dan 2(8,7%) pasien. Pada [Ca]-D tinggi didapatkan 10(43,5%), 8(34,8%), 15(65,2%), 8(34,8%) pasien. Penelitian kami mendapatkan dengan [Ca]-D tinggi hasil lebih baik, hal ini tidak sama dengan hasil penelitian DOPPS. Berbeda dengan PO4 yang hasilnya lebih baik dengan [Ca]-D rendah, namun hasil kami juga lebih baik dari penelitian DOPPS. Hasil pada HPT lebih buruk pada [Ca]-D rendah dibandingkan DOPPS, hal ini mungkin disebabkan kami tidak menggunakan vitamin D untuk mengatasi hiperparatiroid sekundernya. Kalsifikasi vaskular dengan metode KAA pada [Ca]-D tinggi sebanyak 13(48,1%) sedangakan pada [Ca]-D rendah sebanyak 14(51,9%). Dengan metode KAAb pada [Ca]-D tinggi didapatkan kalsifikasi sebanyak 16(47,1%) dan pada [Ca]-D rendah didapatkan 18(52,9%) kalsifikasi. Simpulan : Terdapat perbedaan kadar Ca, PO4, produk Ca x PO4, HPT dan kalsifikasi vaskular, pada penggunaan [Ca]-D tinggi dan rendah, tetapi yang berbeda bermakna hanya Ca dan HPT.

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ABSTRACTBackground : The use of calcium dialysate is still controversial. In Indonesia, the dose for [Ca-D] still varies between 1,25 mmol/L ? 1,85 mmol/L. DOPPS study shows failure in achieving optimal calcium, phosphate as well as parathyroid hormone level in the blood as targetted by K/DOQI and is related to significantly increased mortality and is closely related with increased [Ca]-D.Aim : Evaluate the difference in Serum Ca, PO4, PTH levels and vascular calcification in concentrations of [Ca]-D high and low.Methods : This is a cross sectional study done in Hemodialysis unit in Nephrology Division of Cipto Mangunkusumo hospital. Total subject recruited was 46 patients, 23 patient using low concentration [Ca]-D (1.25 mmol/L) and 23 patients using high concentration [Ca]-D (1.85mmol/L). Research was conducted in October 2013 until May 2014. Analysis was performed using Mann Whitney test and Chi Square, statistical analysis was done using SPSS 20.0.Result : A total of 46 patients consisting of 25 men and 21 women, with mean age of 50,87 + 12,74 years. Mean length of Dialysis was 45,50 months (6-168 months). Subjects using low concentration [Ca]-D who reached target concentration according to K/DOQI consisted of : corrected Ca in 8 (34,8%) patients while in high concentration [Ca]-D consisted of 10(43,5%) patients, better than DOPPS study. In terms of phosphate levels, low concentration [Ca]-D achieved target PO4 level in 10(43,5%) patients while high concentration [Ca]-D achieved target in 8(34,8%) patients. Corrected Ca x PO4 target levels were obtained equally in both groups which was 15(65,2%) patients. Target PTH level was achieved in low concentrated [Ca]-D up to 2(8,7%) patients, very low may be caused we did not use vitamin D and 8(34,8%) patients in high concentrated [Ca]-D. Vascular calcification using KAA method showed incidence of 13(48,1%) in high concentrated [Ca]-D and 14(51,9%) in low concentrated [Ca]-D group. On the other hand, KAAb methods revealed calcification of 16(47,1%) in high concentrated [Ca]-D and 18(52,9%) calcification in low concentrated [Ca]-D.Conclusion : There is a difference in Ca, PO4, Ca X PO4 product serum level and vascular calcification in high and low [Ca]-D in both group however, statistically significant difference was found only in serum Ca and PTH levels."

"Prevelansi penduduk Indonesia yang tidak mendapatkan angka kebutuhan kalsium yang cukup pada masa tumbuh kembang masih relatif tinggi. Anak usia sekolah dan remaja khususnya adalah yang berisiko tinggi pada keadaan ini. Penyebabnya tidak hanya dikarenakan latar belakang status ekonomi mereka saja, namun juga dikarenakan kekurangan informasi mengenai betapa pentingnya mengkonsumsi kalsium di kehidupan sehari-hari.Penelitian ini dilakukan bertujuan untuk mengetahui pengaruh edukasi nutrisi terhadap pengetahuan kalsium pada murid-murid di sebuah pesantren di Jakarta Timur, tahun 2011. Metode penelitian ini menggunakan pre-post intervention design. Sebanyak 67 murid berusia remaja berpartisipasi di dalam penelitian ini, dibagi menjadi dua kategori yaitu 34 murid laki-laki dan 33 murid perempuan. Data diperoleh dengan mengisi kuesioner yang dibagikan sebelum edukasi dan setelah penyampaian edukasi (pretest dan posttest).Hasil penelitian yang diperoleh menggunakan SPSS version 21 dan data dianalisa menggunakan McNemar test dan Wilcoxon test menunjukan bahwa tidak terdapat hubungan yang signifikan antara edukasi yang telah diberikan dengan nilai posttest. Hasil McNemar test menunjukan tidak signifikan (p = 0.304) dan Wilcoxon test juga menunjukan hasil yang insignifikan (p = 0.379).

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The prevalence of Indonesian population who do not get proper calcium intake during their growth and development period is high, in which school-aged children and adolescence are at greatest risk for this condition. Not only due to their economical background, but also it may be caused by their insufficiency of information regarding the importance of calcium consumption in daily lives.

This research aims to evaluate the effect of nutritional education towards the calcium knowledge among pesantren student located in East Jakarta, in the year of 2011. The research method that is used is the pre-post intervention design. Approximately 67 students were divided into two categories, male and female students (34 male students & 33 female students) were given two questionnaires before the nutritional education (pre-test) and after the education (post-test).

The results from the examination were processed by using SPSS version 21, then the data were analyzed using McNemar study and Wilcoxon test. From the results, we can conclude that there is no significant difference between the score of pre-test and post-test. McNemar study shows no significant relationship (p = 0.304), and Wilcoxon test also shows not significant results (p = 0.379)."

"Latar Belakang: Pekerjaan aktivitas fisik rendah (sedentary work) merupakan salah satu faktor risiko terjadinya kristal kalsium oksalat urin. Pada pekerja dengan aktivitas fisik rendah cenderung terjadi stasis urin dan mengakibatkan pengendapan substansi yang terlarut di dalamnya. Hal ini bila dibiarkan terus menerus akan mengakibatkan terjadinya kristal pada urin, termasuk diantaranya adalah kristal kalsium oksalat. Metode: Tujuan dari penelitian ini adalah mengetahui prevalensi kristal kalsium oksalat urin pada pegawai kantor X serta mengetahui hubungan pekerjaan aktivitas fisik rendah (sedentary work) dengan terjadinya kristal kalsium oksalat urin. Penelitian ini menggunakan metode cross sectional dengan analisa kasus kontrol. Dilakukan pengumpulan data selama bulan Juni 2005 yang meliputi karakteristik responden serta faktor risiko dengan wawancara serta pemeriksaan urinalisa. Juga dilakukan pengisian tabel uraian aktivitas kerja masing-masing satu orang pada pegawai golongan sedentary dan non sedentary untuk mendapatkan gambaran pekerjaan. Hasil: Dari 261 responden, didapatkan prevalensi kristal kalsium oksalat urin sebesar 41%. Faktor aktivitas kerja rendah (sedentary work) meningkatkan risiko terjadinya kristal kalsium oksalat urin dibandingkan dengan non sedentary (OR= 7,06; 95% CI 3,33; 14,99). Kebiasaan makan sedang oksalat meningkatkan risiko terjadinya kristal kalsium oksalat urin (OR 21,41; 95% CI 3,85; 118,95) dibandingkan dengan rendah oksalat. Kebiasaan kurang minum air putih akan meningkatkan risiko terjadinya kristal kalsium oksalat (OR 3,94; 95% CI 1,86;8,36) dibandingkan dengan cukup minum air putih. Kesimpulan: Pekerjaan aktivitas fisik rendah (sedentary work), kebiasaan makan sedang oksalat dan kurang minum air putih meningkatkan risiko terjadinya kristal kalsium oksalat urin, sehingga dianjurkan pada pekerja golongan sedentary worker untuk mengurangi konsumsi makanan yang banyak mengandung oksalat dan minum air putih yang cukup.

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Background: Work with low activity (sedentary work) representing one of the risk factors for calcium oxalate crystals in the urine. At sedentary worker tend to happened urine static and result precipitation of dissolve substance in it. This matter when let continuously will result urine crystal, inclusive calcium oxalate crystals.

Methode: The research intention was to know prevalence of calcium oxalate crystal in the urine among office X’s employees, and also to know the correlation between low activity work with the calcium oxalate crystals in the urine. The research design was cross sectional with case control analysis. Data was collected during June 2005 including responden characteristics and also the risk factors with interview and urinalisa test. Its also done admission filling of work activity table each one employee of sedentary and non sedentary.

Result: From 261 respondens, got prevalence of calcium oxalate crystals in the urine equal to 41%. Low activity work (sedentary work) increased risk of the happening calcium oxalate crystals in the urine compared to non sedentary (OR 7,06; 95% CI 3,33; 14,99). Eat habit with medium oxalate increased risk of the happening calcium oxalate crystals in the urine compared to lower oxalate habit (OR 21,41; 95% CI 3,85; 118,95). Less drink water habit increased risk of the happening calcium oxalate crystals in the urine compared to enough drink water habit (OR 3,94; 95% CI 1,86;8,36).

Conclusion: Sedentary work, eat habit with medium oxalate and less drink water habit have proven increased the risk of calcium oxalate crystals in the urine. Therefore it is recommended for sedentary worker to reduce high oxalate food in diet and drink enough water."

"Osteoporosis adalah penyakit tulang yang ditandai oleh penurunan densisitas massa tulang sehingga tulang menjadi rapuh dan mudah patah, disebabkan oleh kurangnya asupan kalsium pada usia muda. Secara tidak langsung, pengetahuan, sikap dan perilaku seorang individu berperan terhadap kebiasaan dalam mengkonsumsi kalsium.Dalam penelitian ini, peneliti ingin mengetahui hubungan antara pengetahuan, sikap dan perilaku tentang asupan kalsium serta faktor-faktor yang berhubungan. Penelitian dilakukan di Fakultas Kedokteran Universitas Indonesia dengan desain Cross-sectional. Sebanyak 108 subyek telah di pilih secara random. Pada awal penelitian, subyek diminta mengisi identitas umum berupa nama, usia, asal pulau, pendidikan & pekerjaan orangtua, dan dilakukan pengukuran TB, BB, dan lingkar badan, kemudian subyek harus mengisi kuisioner pengetahuan, sikap dan perilaku tentang asupan kalsium.Di akhir penelitian, peneliti menganalisis seluruh data yang didapatkan dan mencari hubungan diantaranya. Sebanyak 76,9% responden memiliki pengetahuan baik, 84,3 % memiliki sikap positif dan 82,4% memiliki perilaku kurang. Tidak terdapat hubungan bermakna antara pengetahuan dengan sikap tentang asupan kalsium (p > 0,05; fisher2 sided), dan antara pengetahuan dengan perilaku tentang asupan kalsium (p > 0,05; fisher2 sided). Namun untuk pengujian kategori sikap terhadap perilaku tentang asupan kalsium didapatkan hubungan bermakna (p < 0,05; fisher2 sided). Tidak terdapat hubungan antara usia, jenis kelamin, dan asal daerah dengan pengetahuan tentang asupan kalsium (p>0,05; Chi Square), dan antara tingkat pendidikan orangtua dengan pengetahuan subyek tentang asupan kalsium (p>0,05; kolmogorov-Smirnov). Pengetahuan tentang asupan kalsium tidak memiliki hubungan bermakna dengan sikap dan perilaku terhadap asupan kalsium, sedangkan sikap tentang asupan kalsium memiliki hubungan bermakna dengan perilaku tentang asupan kalsium.

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Osteoporosis is a bone disease which is characterized by decreasing of bone mass density. It makes bones become brittle and easily broken. The reason behind this disease is because of inadequate calcium intake during adolescence. Indirectly, knowledge, attitude and behavior of an individual also can contribute into the habit of calcium consumption.

In this research, the researcher wanted to know the relationship between knowledge, attitudes and behaviors about calcium intake and other related factors. This research design is cross-sectional and has 108 subjects who were chosen randomly.

Subjects were asked to fill their identity form that consists of name, age, gender, origin, parental education &occupation, body weight and height, then filled the questionnaire of knowledge, attitude and behavior about calcium intake.

At the end, researcher analyzed the data and was looking for the relationship between them.The number of subjects that have good knowledge are 83 people (76,9%), positive attitude are 91 people (84,3%), poor behavior are 89 people (82,4%). There was no significant relationship between knowledge with attitude regard to calcium intake (p>0.05,Fisher test), and knowledge with behavior regard to calcium intake (p>0.05,Fisher test). But, there was a significant relationship between attitudes with behavior about calcium intake (p <0.05, Fisher test). Furthermore, there was no relationship between age, gender, and origin with the knowledge about calcium intake (p>0.05,Chi Square), and between parent’s education level with knowledge about calcium intake (p>0.05,Kolmogorov-Smirnov). Knowledge about calcium intake had no significant relationship with attitude and behavior of taking calcium, while attitude in consuming calsium has a meaningful relationship with consuming calcium’s behaviors."

"Karakteristik lapisan anodik oksida hasil anodisasi sangat dipengaruhi oleh jenis elektrolit dan input tegangan yang digunakan selama proses anodisasi. Pada penelitian ini dilakukan anodisasi paduan Ti-6Al-4V di dalam larutan kalsium hidroksida pada kondisi variasi tegangan 10, 20, dan 30 V. Penelitian ini bertujuan untuk menganalisis perilaku korosi paduan akibat perlakuan anodisasi. Proses anodisasi dilakukan pada suhu 25°C selama 20 detik. Proses anodisasi direkam dengan menggunakan digital multimeter untuk menghasilkan kurva arus terhadap waktu anodisasi. Karakterisasi komposisi fasa dan unsur yang terbentuk setelah anodisasi dilakukan dengan uji XRD and EDS. Uji korosi dilakukan dengan metode elektrokimia menggunakan mode: open circuit potential (OCP), polarisasi potensiodinamik (PDP), dan spektroskopi impedansi (EIS). Dari hasil karakterisasi komposisi unsur menggunakan EDS menunjukkan fasa Oksigen yang tinggi pasca anodisasi menandakan bahwa pembentukan lapisan oksida telah terbentuk. Hasil kekerasan Vickers menunjukkan bahwa nilai kekerasan sampel Ti-6Al-4V berada pada rentang 325-380 HV. Sampel dengan variasi tegangan tertinggi (30V-Ca) memiliki ketahanan korosi tertinggi (Icorr=1,16 x10-6A/cm2; Ecorr=-0,18 V). Dalam uji imersi selama 31 hari pada larutan Ringer yang dimodifikasi belum terlihat fasa apatit dalam hasil XRD, hal ini dikarenakan permukaan paduan logam titanium yang inert baik sebelum dan setelah proses anodisasi.

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The characteristics of the anodized anodic oxide layer are strongly influenced by the type of electrolyte and the input voltage used during the anodization process. In this study, the anodization of Ti-6Al-4V alloy in calcium hydroxide solution was conducted under various stress conditions of 10, 20, and 30 V. This study analyzed the corrosion behavior of the alloy due to anodizing treatment. The anodization process was conducted at a temperature of 25°C for 20 seconds. The anodization process was recorded using a digital multimeter to produce a current versus anodization time curve. The characterization of the phase and elemental compositions formed after anodization was conducted using XRD and EDS tests. Corrosion tests were conducted by electrochemical methods using the following modes: open circuit potential (OCP), potentiodynamic polarization (PDP), and impedance spectroscopy (EIS). The results of the characterization of elemental composition using EDS showed a high oxygen phase after anodization, indicating that the formation of an oxide layer had been formed. The sample with the highest voltage variation (30V-Ca) had the highest corrosion resistance (Icorr=1.16 x10-6A/cm2; Ecorr=-0.18 V). In the immersion test for 31 days in the modified Ringer's solution, the apatite phase was not visible in the XRD results, which was due to the inert surface of the titanium metal alloy both before and after the anodization process"

"Tulang adalah jaringan tubuh yang dapat menyembuhkan dirinya sendiri apabila mengalami kerusakan. Namun pada beberapa kasus cacat tulang, cangkok tulang (bone graft) atau material pengganti tulang dibutuhkan untuk membantu penyembuhan jaringan. Terdapat tiga jenis cangkok tulang yaitu autograf, allograf, dan xenograf. Karena terbatasnya sumber tulang untuk cangkok tulang, peneliti mencari material alternatif sebagai pengganti tulang. Biokeramik telah banyak diteliti karena dinilai sebagai material yang paling menjanjikan sebagai pengganti tulang. Bifasik kalsium fosfat (BCP), tersusun atas hidroksiapatit (HA) dan b-trikalsium fosfat (b-TCP), menunjukkan potensi besar sebagai material pengganti tulang karena sifatnya yang bioaktif, biokompatibel, dan laju degradasi yang cocok dengan laju pertumbuhan tulang. Hidroksiapatit di sintesis dengan metode presipitasi gelombang mikro. Serbuk hidroksiapatit dicampurkan ke dalam larutan polivinil alkohol yang bertujuan untuk menghasilkan hidroksiapatit dengan mikrostruktur berpori. Selanjutnya, serbuk hidroksiapatit dipadatkan dan disintering dengan variasi temperatur sintering mulai dari 800 °C hingga 1300 °C untuk mempelajari perubahan fasa dan mikrostruktur dari hidroksiapatit. Fase kristal, gugus fungsi, morfologi, dan sifat mekanik diuji dengan X-ray Diffraction (XRD), Fourier Transform Infrared FTIR, Scanning Electron Microscope (SEM), dan Mikro Vickers. XRD menunjukkan terjadi perubahan fase HA menjadi b-TCP pada temperatur 1000 – 1300 °C. Hasil FTIR menunjukkan tidak ditemukannya gugus vinil yang berarti PVA telah sepenuhnya terdegradasi akibat sintering dengan temperatur tinggi. Pori yang dihasilkan memiliki bentuk spherical-like dengan ukuran yang semakin besar seiring dengan peningkatan temperatur sintering. Nilai kekerasan maksimal sebesar 4,166 GPa dihasilkan oleh hidroksiapatit yang disintering pada temperatur 1200 °C dan kekerasan menurun pada temperatur diatasnya karena peningkatan dekomposisi HA.

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Bone is a tissue that can heal by itself. However, for some cases of bone defects, a bone graft or bone substitute is needed to help bone tissue to heal. There are three kinds of bone grafting which is autograft, allograft, and xenograft. Due to the limited source of bone for bone grafting, researchers eager to find an alternative material for bone substitution. Bioceramic has been widely studied because they are considered the most promising material for bone tissue substitution. Biphasic calcium phosphate (BCP), composed of hydroxyapatite (HA) and b-tricalcium phosphate (b-TCP), has shown great potential as a bone substitute material due to its bioactive, biocompatible properties and the rate of degradation that corresponds to the growth rate of bone. Hydroxyapatite nanocrystal was synthesized through the microwave-assisted precipitation method. Hydroxyapatite powder was later added into a polyvinyl alcohol solution, which is aimed to produced hydroxyapatite with a porous microstructure. Hydroxyapatite powder was compacted and sintered at various temperatures, from 800 – 1300 °C, to study the transformation of phase and microstructure of hydroxyapatite. The crystal phase, functional groups, morphology, and hardness of biphasic calcium phosphate were determined through X-Ray Diffraction (XRD), Fourier Transform Infrared (FTIR) Spectroscopy, Scanning Electron Microscope (SEM), and Vickers Microhardness Tester. XRD result shows that the b-TCP phase appears due to the decomposition of HA at 1000 – 1300 °C. FTIR result shows there is no sign of a vinyl functional group, which means that PVA has fully degraded due to sintering with high temperature. Produced pores have a spherical-like shape and become larger as the sintering temperature reaches up to 1300 °C. The maximum hardness value of 4,166 GPa obtained from the hydroxyapatite sintered at 1200 °C and slightly decreased at 1300 °C due to increased decomposition of HA"

"Dalam penelitian ini telah dilakukan fabrikasi suatu kamar reaksi baru yang akan ditempatkan pada alat difraksi sinar X (XRD). Penelitian dilanjutkan dengan investigasiex situ dari serbuk kalsium fosfat hasil sintesis kimiawi dengan variasi waktu kontak dengan ammonia selama 0, 3, 4, 5, 15, dan 36 jam yang secara khusus ditujukan untuk menginvestigasi proses mineralisasi kalsium fosfat. Selama transformasi kalsium fosfat menjadi hidroksiapatit, telah terdeteksi adanya pembentukan fase-fase perantara, yaitu brushite dan monetite, melalui karakterisasi XRD. Hasil penelitian juga menunjukkan bahwa meningkatnya waktu kontak ammonia dari 4 hingga 36 jam mampu meningkatkan ukuran kristalit mineral dari 9.3 menjadi 16.1 nm. Hasil-hasil penelitian ini dapat dijadikan acuan untuk investigasi lebih lanjut mengenai mineralisasi kalsium fosfat, khususnya melalui investigasi in situ via XRD.

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In the current research, fabrication of newly-designed reaction chamber for X-Ray Diffraction (XRD) has been conducted, followed by ex situ investigation of chemically synthesized CaPwith various time of 0, 3, 4, 5, 15, and 36 hours in contact with ammonia. This route was specifically aimed at investigating the mineralization of CaP. During the transformation of CaP toHydroxy Apatite(HA), formation of intermediate phases, i.e. brushite (DCPD) and monetite (DCPD) is well detected by XRD characterization. Increasing of contact time with alkali atmosphere from 4 to 36 hours has increased the crystallite size of CaP minerals from 9.3 to 16.1 nm. Those results can be a baseline for further investigation of CaP mineralization, especially in situ XRD investigation."