Judul: Mapping Distribution of Nitrogen Dioxide (NO2) Pollutants  Due to Forest and Land Fires in Dumai City
Abstrak: Kota Dumai merupakan salah satu daerah di Provinsi Riau yang memiliki kasus kebakaran hutan dan lahan yang tinggi. Kebakaran hutan dan lahan akan berdampak buruk pada kualitas udara apabila tidak dilakukan penanggulan yang baik. Oleh karena itu perlu dilakukannya peninjauan lebih lanjut terkait pencemaran udara terutama yang disebabkan oleh polutan NO2 dengan menggunakan metode yang terukur. Tujuan penelitian ini adalah mengetahui pemetaan sebaran polutan Nitrogen Dioksida (NO2) akibat kebakaran hutan dan lahan di Kota Dumai yang terjadi pada tahun 2019. Metode yang digunakan adalah penginderaan jauh dengan menggunakan data Ozone Monitoring Instrument (OMI) NO2 dan data curah hujan yang didapatkan dari satelit Tropical Rainfall Measuring Mission (TRMM). Prosedur penelitian dimulai dengan pengumpulan dan pengolahan data. Kemudian dilakukan pembagian periode analisis berdasarkan pola curah hujan bulanan, analisis sebaran polutan NO2 menjadi 4 periode, dan visualisasi menggunakan software ArcGis. Konsentrasi NO2 di Kota Dumai pada tahun 2019 berada pada rentang 28 – 39 µg/m3 dan masih berada dibawah baku mutu sebesar 150 µg/m3. Curah hujan dan konsentrasi NO2 memiliki korelasi yang negatif, dimana konsentrasi NO2 akan tinggi pada saat curah hujan rendah., Dumai City is one of the areas in Riau Province that has high cases of forest and land fires. Forest and land fires will have a negative impact on air quality if good management is not carried out. Therefore, it is necessary to conduct a further review related to air pollution, especially those caused by NO2 pollutants using measured methods. The purpose of this study was to find out the mapping of the distribution of Nitrogen Dioxide (NO2) pollutants due to forest and land fires in Dumai City that occurred in 2019. The method used was remote sensing using Ozone Monitoring Instrument (OMI) NO2 data and rainfall data obtained from Tropical Rainfall Measuring Mission (TRMM) satellite. The research procedure begins with data collection and processing. Then the analysis period is divided based on monthly rainfall patterns, analysis of NO2 pollutant distribution into 4 periods, and visualization using ArcGIS software. The concentration of NO2 in Dumai City in 2019 was in the range of 28 – 39 g/m3 and was still below the quality standard of 150 g/m3. Rainfall and NO2 concentration have a negative correlation, where NO2 concentration will be high when rainfall is low.
Keyword: Kota Dumai, nitrogen dioksida, pencemaran udara, penginderaan jauh

Judul: Estimation of Forest, Plantation, and Land Fires Severity Using Remote Sensing in Dumai, Riau
Abstrak: Kebakaran hutan, kebun, dan lahan merupakan peristiwa terbakarnya hutan dan/atau lahan yang menimbulkan kerugian diberbagai sektor seperti bahaya bencana ekologi, ekonomi, sosial budaya, dan politik. Karhutbunla terjadi akibat dua faktor yaitu faktor alami dan aktivitas manusia. Proses alami terjadinya karhutbunla disebabkan oleh aktivitas pembakaran yang tidak sengaja dan tidak terkendali seperti letusan gunung berapi, sambaran petir pada pohon, serta faktor iklim dan cuaca lainnya. Kota Dumai merupakan salah satu areal terbakar terluas pada tahun 2023. Kota Dumai memiliki lahan gambut seluas 163,141 ha (78%) yang mudah terbakar akibat adanya bahan organik pada tanah. Penelitian ini mengestimasi tingkat keparahan kebakaran hutan, kebun, dan lahan di Kota Dumai pada 2023 menggunakan penginderaan jauh. Penelitian ini menggunakan metode ekstraksi indeks Normalized Burn Ratio yang memetakan area terbakar dan tingkat keparahannya. Hasil menunjukkan area terbesar terjadinya karhutbunla yaitu pada tingkat keparahan “rendah” dengan luas 3.909,67 ha (1,72%). Akurasi menunjukkan tingkat baik (86,67%) untuk identifikasi area terbakar dan tingkat cukup (69%) untuk identifikasi tingkat keparahan kebakaran., Forest, plantation, and land fires are the burning land area that cause losses in sectors such as ecological, economic, social culture, and political dangers and catastrophes. Forest, plantation, and land fires come as a result of two factors: natural factors and human activities. The natural process of the burning is caused by involuntary and uncontrolled burning activities such as volcanic eruptions, lightning strikes in trees, and other climate and weather factors. Dumai city was one of the largest cities with the burning area in 2023. Dumai city had a peat land area of 163,141 ha (78%) that has a tendenct to be flammable because of the accumulation of organic matter in the soil. This study will estimate the severity of forest, plantation, and land fires of Dumai city in 2023 by using remote sensing technology. This research method used is the normalized burn ratio that maps the burn area with its severity. The analysis of the extraction index shows the largest burn areas of forest, plantation, and land area on “low severity” class with an area of 3.909,67 ha (1,72%). Accuracy testing results in a level of good accuracy (86,67%) on burnt area identification and edaquate accuracy (69%) on the burnt severity identification.
Keyword: area terbakar, kebakaran hutan dan lahan, penginderaan jauh

Judul: Mathematical model of Hematopoietic Stem Cell in Chronic Myelogenous Leukemia with and without Therapy
Abstrak: Leukemia or blood cancer is a diverse group of neoplastic disease, characterized by the multiplication of abnormal leukocytes or malignant transformation of blood-forming cells in bone marrow and lymphoid tissues. One of the most common types of leukemia is Chronic Myelogenous Leukemia (CML), which is usually diagnosed by the presence of certain chromosomal abnormalities, the so-called Philadelphia chromosome (Ph). One of the treatments of CML is Granulocyte Colony-Stimulating Factor (G-CSF). In this paper, we discuss two Hematopoietic Stem Cell (HSC) models, i.e. HSC without treatment and HSC with G-CSF treatment. The model of HSC without treatment included three equations representing the dynamics of HSC, leukocyte and platelet. Whereas, the model of HSC with G-CSF treatment includes the previous three equations and adds two more equations representing G-CSF injection and G-CSF circulation. The stability behavior of the system approaching the equilibrium points in the simulation study is carried out using Mathematica 7.0. The simulation results show that the G-CSF treatment can successfully decrease the number of HSC, which means reducing the CML.
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