Judul: Analysis of PM2.5 and Its Precursor Pollutants (NOx) Concentration Fluctuations and Their Relationship with Meteorological Factors in Rural Areas (Case Study: Puncak Bogor)
Abstrak: Wilayah Puncak Bogor merupakan wilayah rural yang didominasi oleh kegiatan pertanian. Salah satu polutan yang dihasilkan oleh aktivitas pertanian adalah ammonia (NH3), yang berkontribusi terhadap pembentukan partikulat sekuder, dengan prekursor NOx. Fluktuasi konsentrasi partikulat dan prekursornya dipengaruhi juga oleh faktor meteorologi. Penelitian ini bertujuan untuk menganalisis hubungan konsentrasi PM2.5 dengan konsentrasi prekursornya (NOx) berdasarkan fluktuasi konsentrasi di wilayah Puncak Bogor serta menganalisis faktor meteorologi yang berkontribusi terhadap fluktuasi konsentrasi PM2.5 dan prekursornya (NOx) di wilayah Puncak Bogor. Data yang digunakan adalah data konsentrasi PM2.5, NOx, NO, NO2, suhu udara, kelembaban relatif, curah hujan, serta arah dan kecepatan angin tahun 2019 dan 2020 yang dianalisis menggunakan korelasi dan regresi linier serta menggunakan package openair di RStudio. Hasil penelitian menunjukkan konsentrasi PM2.5 dengan NOx sebagai prekursornya memiliki korelasi positif yang signifikan baik pada tahun 2019 (r = 0,68) maupun tahun 2020 (r = 0,63). Peningkatan konsentrasi PM2.5 di siang hari serta penurunan konsentrasi di malam hari dikaitkan dengan adanya pengaruh angin lembah dan angin gunung yang berhembus di wilayah Puncak Bogor. Faktor meteorologi (suhu udara, kelembaban relatif, dan kecepatan angin) memiliki nilai korelasi yang kecil terhadap fluktuasi konsentrasi PM2.5, demikian pula terhadap fluktuasi konsentrasi NOx kecuali untuk suhu udara (r = 0,3)., Puncak Bogor is a rural area which is dominated by agricultural activities. One of the pollutants produced by agricultural activities is ammonia (NH3) which contributes to the secondary particulates formation, with the NOx precursor. The fluctuation of particulates and its precursor concentration are also influenced by meteorological factors. This study aims to analyze the relationship between PM2.5 concentration and its precursor (NOx) based on concentration fluctuations in Puncak Bogor and also to analyze the meteorological factors that contribute to the PM2.5 and its precursor (NOx) concentration fluctuations in Puncak Bogor. The data used are concentrations of PM2.5, NOx, NO, NO2, temperature, relative humidity, rainfall, and wind in 2019 and 2020 which were analyzed using correlation and linear regression and also using the openair package in RStudio. The results showed that PM2.5 concentration with NOx as precursors had a significant positive correlation both in 2019 (r = 0,68) and 2020 (r = 0,63). The increased and decreased of PM2.5 concentration during the day and night was influenced by valley and mountain winds that blow to the Puncak Bogor. Meteorological factors (air temperature, relative humidity, and wind speed) had a small correlation value to PM2.5 concentration fluctuations, as well as to NOx concentration fluctuations, except for air temperature (r = 0,3).
Keyword: meteorological factors, NOx, PM2.5, precursors, secondary particulates

Judul: Analysis of the Contribution of SO2 and NOx as Precursors to PM2.5 Concentrations in Puncak and Baranangsiang
Abstrak: Pencemar partikulat halus berupa PM2.5 di atmosfer dikelompokkan menjadi partikel primer dan partikel sekunder. Pembentukan PM2.5 sekunder berasal dari reaksi kimia di atmosfer akibat adanya prekursor seperti SO2, NOx, dan VOC. Penelitian ini bertujuan untuk menganalisis kontribusi SO2 dan NOx sebagai prekursor terhadap konsentrasi PM2.5 di wilayah Puncak dan Baranangsiang, Bogor. Wilayah Puncak dapat dianggap mewakili daerah rural, sedangkan Baranangsiang mewakili karakteristik sub-urban. Data yang digunakan adalah data konsentrasi PM2.5, NOx, NO, NO2, SO2, dan data curah hujan wilayah Puncak Bogor dan Baranangsiang. Data diolah menggunakan package openair pada perangkat lunak RStudio dan dianalisis menggunakan korelasi dan regresi linier. Hasil regresi linear berganda tahunan menunjukkan prekursor yang memiliki kontribusi lebih besar terhadap pembentukan PM2.5 di wilayah Puncak adalah NOx (R2 = 43,4%) sedangkan di Baranangsiang adalah SO2 (R2 = 8,6%). Pengaruh musim menunjukkan pada periode bulan kering konsentrasi PM2.5 beserta prekursornya lebih tinggi dibanding pada periode bulan basah. Berdasarkan nilai koefisien determinasi, kontribusi NOx terhadap pembentukan PM2.5 di wilayah Puncak lebih besar daripada SO2, sedangkan di wilayah Baranangsiang kontribusi SO2 lebih besar dibandingkan dengan NOx. Pengaruh prekursor baik SO2 dan NOx terhadap konsentrasi PM2.5 lebih terlihat di wilayah Puncak Bogor dibandingkan dengan wilayah Baranangsiang. Fluktuasi konsentrasi PM2.5 di wilayah Puncak dan Baranangsiang dipengaruhi oleh sumber emisi primer dan keberadaan prekursor. Perbedaan prekursor di Puncak Bogor dan Baranangsiang dapat disebabkan karena perbedaan kondisi wilayah dan lingkungan, sumber pencemar, serta faktor meteorologi yang berperan penting dalam proses pembentukan PM2.5 dari prekursor., Fine particulate pollutants in the form of PM2.5 in the atmosphere are grouped into primary particles and secondary particles. The formation of secondary PM2.5 comes from chemical reactions in the atmosphere due to the presence of precursors such as SO2, NOx, and VOC. This study aims to analyze the contribution of SO2 and NOx as precursors to PM2.5 concentrations in the Puncak and Baranangsiang areas, Bogor. Puncak area can be considered to represent rural areas, while Baranangsiang represents sub-urban characteristics. The data used are data on concentrations of PM2.5, NOx, NO, NO2, SO2, and rainfall data for the Puncak Bogor and Baranangsiang areas. Data were processed using the openair package on RStudio software and analyzed using correlation and linear regression. The annual multiple linear regression results show that the precursor that has a greater contribution to the formation of PM2.5 in the Puncak area is NOx (R2 = 43.4%) while in Baranangsiang it is SO2 (R2 = 8.6%). The influence of the season shows that in the dry months the concentration of PM2.5 and its precursors is higher than in the wet months. Based on the value of the coefficient of determination, the contribution of NOx to the formation of PM2.5 in the Puncak area is greater than that of SO2, while in the Baranangsiang area the contribution of SO2 is greater than that of NOx. The effect of both SO2 and NOx precursors on PM2.5 concentrations was more visible in the Puncak Bogor area compared to the Baranangsiang area. Fluctuations in PM2.5 concentrations in the Puncak and Baranangsiang areas are influenced by primary emission sources and the presence of precursors. Differences in
Keyword: meteorological factor, NOx, PM2.5, precursors, SO2

Judul: Posisi Filogenetik Kura-Kura Carettochelys Insculpta  (Reptillia: Testudinata)
Abstrak: Carettochelys insculpta is an endemic freshwater turtle of southern Papua and northern Australia. Phylogenetic position of this turtle is remain unresolved until now. Most of the research conducted show close relationships of C. insculpta and members of Trionychidae family. However, some of the research show distance between C. insculpta and members of Trionychidae family. This research is conducted to analyze phylogenetic relationship between C. insculpta and other members of Testudinata using 12S rRNA, 16S rRNA, and both gene as markers. DNA samples were obtained from three different organisms of C. insculpta. Two species used as outgroups were Alligator mississippiensis and Iguana iguana. Phylogenetic analysis was carried out using Neighbor-Joining method with Felsenstein 1981 (F81) modeltest. A polytomy tree of Testudinata was produced by using 12S rRNA gene. However, analysis using 16S rRNA and both genes as markers confirmed that C. insculpta was located between the Chelonidae and the Trionychidae family.
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