Judul: The Role of Foreign Public Debt to Foreign Exchange Reserve in Middle Income Countries: Does Governance Affect?
Abstrak: Utang luar negeri dan cadangan devisa memiliki peranan penting dalam pertumbuhan ekonomi. Kedua hal tersebut memiliki hubungan dua arah yaitu utang luar negeri dapat meningkatkan cadangan devisa serta cadangan devisa digunakan sebagai pembayaran kembali utang luar negeri. Untuk menguji utang luar negeri tepatnya utang publik luar negeri terhadap cadangan devisa, penelitian ini menggunakan data panel 22 middle-income countries dengan menginteraksikan tata kelola pemerintah pada periode 2013 hingga 2022. Penelitian ini menggunakan analisis panel statis. Perkembangan utang publik luar negeri serta cadangan devisa cukup berfluktuasi. Tata kelola pemerintah di wilayah tersebut tertinggi pada tahun 2022 yaitu pada indikator Regulatory Quality serta terendah yaitu Rule of Law. Random Effect Model menemukan bahwa utang publik luar negeri meningkatkan cadangan devisa. Namun, utang publik luar negeri belum optimal meningkatkan cadangan devisa karena rendahnya tingkat kepatuhan hukum. Sementara tingkat akuntabilitas pemerintah memperkuat peran utang publik luar negeri terhadap cadangan devisa. Faktor lainnya yang mempengaruhi cadangan devisa yaitu structural transformation, ekspor, labor, financial development serta foreign direct investment., Foreign debt and foreign exchange reserves play an important role in economic growth. Both of these have a two-way relationship, namely foreign debt can increase foreign exchange reserves and foreign exchange reserves are used as repayment of foreign debt. To examine foreign debt, specifically foreign public debt, on foreign exchange reserves, this study uses panel data of 22 middle-income countries by interacting government governance in the period 2013 to 2022. This study uses static panel analysis. The development of foreign public debt and foreign exchange reserves fluctuated. Governance in the region is highest in 2022 in the Regulatory Quality indicator and the lowest is Rule of Law. The Random Effect Model found that foreign public debt increases foreign exchange reserves. However, foreign public debt has not optimally increased foreign exchange reserves due to the low level of legal compliance. Meanwhile, the level of government accountability strengthens the role of foreign public debt on foreign exchange reserves. Other factors that affect foreign exchange reserves are structural transformation, exports, labor, financial development and foreign direct investment.
Keyword: Cadangan devisa, Middle income countries, Utang publik luar negeri, Tata kelola pemerintah

Judul: Effect of Government Debt on Economic Growth in Lower Middle Income Countries
Abstrak: Utang pemerintah negara-negara middle income cenderung meningkat, sedangkan pertumbuhan ekonomi dan total pembayaran utangnya cenderung menurun. Negara middle income dibagi menjadi dua, lower middle dan upper middle. Utang pemerintah negara-negara lower middle income cenderung meningkat lebih signifikan daripada upper middle income. Jika peningkatan utang tersebut terjadi secara terus menerus, dikhawatirkan akan muncul pengaruh negatif utang. Penelitian ini menggunakan metode variabel instrumental untuk menganalisis pengaruh utang pemerintah terhadap pertumbuhan ekonomi di 27 negara lower middle income dari tahun 2000 sampai 2018. Model estimasi yang terpilih adalah Random Effect Model yang menunjukkan bahwa utang pemerintah memiliki hubungan non-linear berbentuk kurva konkaf dan berpengaruh signifikanterhadap pertumbuhan ekonomi. Ketika utang pemerintah belum melebihi 51,7 persen maka dampaknya akan positif terhadap pertumbuhan ekonomi. Lebih dari itu, dampaknya akan menjadi negatif. Variabel lain yang turut berpengaruh terhadap pertumbuhan ekonomi adalah lag PDB per kapita, pertumbuhan populasi, dan pembentukan modal bruto. Sementara itu, variabel keterbukaan perdagangan tidak berpengaruh signifikan terhadap pertumbuhan ekonomi pada taraf nyata 5 persen., Middle income countries' government debt tends to increase, while economic growth and total debt payments tend to decline. Middle income countries are divided into two, lower middle and upper middle. The government debt of lower middle income countries tends to increase more significantly than the upper middle income. If the increase in debt occurs continuously, it is feared that the negative impact of debt will emerge. This study uses the instrumental variable method to analyze the effect of government debt on economic growth in 27 lower middle income countries from 2000 to 2018. The estimation model chosen is the Random Effect Model which shows that government debt has a non-linear relationship in the form of a concave curve and has a significant effect on economic growth. When the government debt does not exceed 51,7 percent, the impact will be positive on economic growth. More than that, the impact will be negative. Other variables that also affect economic growth are lag of GDP per capita, population growth, and gross capital formation. Meanwhile, the trade openness variable has no significant effect on economic growth at the 5 percent real level.
Keyword: defisit, pertumbuhan ekonomi, utang pemerintah, deficit, economic growth, government debt

Judul: Hydrothermal Synthesis of Biphasic Calcium Posphate
Abstrak: Biphasio calsium phosphate (BCP), which was a mixture of hydroxypatite (HA) and tricalcium phosphate (TCP), was synthesized by hydrothermal method followed by sintering process. Hydroxyapatite was produced by using natural calcium source CaO from hen's eggshell and (NH4)2HPO4 as phosphate souce, other hydroxyapatite sample was produce by using synthetic calcium source Ca(OH) and H3PO4 as phosphate source.
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