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Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Papua Jalan Gunung Salju Amban, Manokwari 98314
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Jurnal Natural
Published by Universitas Papua
ISSN : 14121328     EISSN : 2746427X     DOI : -
Core Subject : Science, Education, Agriculture,
Agriculture, Biological Sciences & Forestry Chemistry Mathematics Physics
Jurnal Natural merupakan jurnal ilmu-ilmu matematika dan pengetahuan alam (basic science) untuk bidang: matematika, kimia, statistika, biologi, dan fisika termasuk ilmu terapan yang terkait seperti bioteknologi, kimia pangan, keanekaragaman hayati, dan lain-lain.
Arjuna Subject : Umum - Umum
Articles 170 Documents
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the KARAKTERISASI MORFOLOGI DAN BIOKIMIA ISOLAT PGPR DARI RUMPUT GAJAH (Pennisetum purpureum): KARAKTERISASI MORFOLOGI DAN BIOKIMIA ISOLAT PGPR DARI RUMPUT GAJAH (Pennisetum purpureum) Rahmat Lamadi; Maria Massora; Rina A. Mogea; Hermawaty Abubakar; Rinondon Altje R Mogea
Jurnal Natural Vol. 22 No. 1 (2026): Jurnal Natural
Publisher : FMIPA Universitas Papua

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30862/jn.v22i1.308

Abstract

Intensive and prolonged use of inorganic fertilizers in Indonesia remains predominant among farmers; however, it can lead to soil contamination and reduced fertility over time. Biofertilizers provide a sustainable alternative, with Plant Growth-Promoting Rhizobacteria (PGPR) serving as key components naturally associated with plant roots. This study aimed to isolate and characterize PGPR from the roots of elephant grass (Pennisetum purpureum) collected from Amban Pantai Manokwari- West Papua. Isolation procedures involved preparing PGPR starters, purifying colonies, and conducting macroscopic and microscopic observations along with biochemical tests. Macroscopic analysis revealed six isolates with white colonies; shapes were circular (PGPR 1 and 5) or irregular (others); elevations included convex, raised, flat, and umbonate; margins were undulate or rhizoid; and oxygen requirements ranged from aerobic, obligate aerobic, anaerobic, to facultative anaerobic. Microscopically, all isolates were rod-shaped and motile, with Gram-positive (PGPR 2 and 3) or Gram-variable (PGPR 1, 4, 5, and 6) characteristics. Biochemical assays indicated positive sucrose fermentation (all isolates, though partial in some), lactose and dextrose fermentation (mainly PGPR 1 and 3), gelatin hydrolysis (PGPR 1, 3, and 5), citrate utilization (PGPR 5), MR positivity (all isolates), VP positivity (PGPR 2 and 4), H₂S production (only PGPR 4), negative indole, and absence of gas production. These findings demonstrate significant morphological and metabolic diversity among the isolated PGPR, underscoring their potential as biofertilizer candidates for sustainable agriculture in tropical regions such as West Papua. The characterization analysis revealed that the isolates belong to the genera Bacillus (PGPR 1, 2, 3, 5, 6) and Enterobacter (PGPR 4).
Characteristics of Briquettes Produced from Corn Cob and Corn Stalk Charcoal Blends David Mangallo; Thomas Pagasis; Bertha Mangallo
Jurnal Natural Vol. 22 No. 1 (2026): Jurnal Natural
Publisher : FMIPA Universitas Papua

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30862/jn.v22i1.305

Abstract

Corn cobs and corn stalks represent abundant agricultural residues with significant potential for conversion into solid biofuels. This study aimed to evaluate the physicochemical characteristics of briquettes produced from varying proportions of corn cob charcoal and corn stalk charcoal. Carbonization was conducted through pyrolysis using a modified oil-drum reactor. The resulting char was pulverized and sieved to 60 mesh to ensure particle uniformity prior to briquetting. A 5% tapioca starch solution was used as a binding agent, and briquettes were formed using a hydraulic press in a honeycomb configuration (4-inch diameter, 16 central perforations). Five different charcoal composition ratios were prepared and analyzed. Proximate analysis revealed moisture content ranging from 4.68% to 5.71%, ash content from 12.27% to 17.23%, volatile matter from 16.24% to 21.62%, and fixed carbon from 56.47% to 65.78%. The calorific value varied between 5,138 and 5,274 cal/g. The results demonstrate that blended corn cob and corn stalk charcoal briquettes exhibit favorable fuel properties and potential applicability as sustainable alternative energy sources.
Development and Performance Test of Vertical Stirrer Rotary Blade Type of Sago Starch Extraction Machine Powered by Gasoline Engine Darma Darma; Reniana Reniana; Risma Uli Situngkir; Arens T. Solissa
Jurnal Natural Vol. 22 No. 1 (2026): Jurnal Natural
Publisher : FMIPA Universitas Papua

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30862/jn.v22i1.309

Abstract

Sago starch extraction is aimed to separate starch as much as possible from waste or fibre. The efficiency and effectiveness of extraction process depend on several factors i.e. the characteristics of extraction machine and fineness degree of disintegrated sago pith is being processed. In previously study, it had been resulted stirrer rotary blade type of sago starch extraction machine powered by gasoline engine. The purpose of this study was to develop and test the performances of stirrer rotary blade type of sago starch extractor. The developed machine was tested it’s performances under 4 levels of extraction duration time i.e. 10 minutes, 15 minutes, 20 minutes and 25 minutes. The Parameter have been measured to evaluate the machine’s performances were (1) extraction capacity, (2) starch rendement, (3) starch yield and (4) starch losses in sago pith waste. Based on performance test results have shown that the developed machine has higher performance than previously prototype. The results showed that extraction duration time significantly affect extraction capacity, starch rendement, and starch losses in sago pith waste, however the starch yield was not affected significantly. The highest performance was resulted at extraction duration time 15 minutes. The performances of the machine at the condition were (1) extraction capacity 247 kg repos/hour, (2) starch rendemen 37,35%, (3) starch yield 78,81 kg/hour, and (4) starch losses in sago pith waste 2,00%.
Nutritional Profile of Awyu and Yaqai Girls in Mappi Regency, South Papua: Marice Dou, Postgraduate Program, Biology Study Program, University of Papua Marice Dou; Febriza Dwiranti; Elda Irma Jeanne Joice Kawulur
Jurnal Natural Vol. 22 No. 1 (2026): Jurnal Natural
Publisher : FMIPA Universitas Papua

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30862/jn.v22i1.313

Abstract

ABSTRACT Nutritional status is a condition determined by the extent to which the body’s physiological needs for energy and nutrients are met through dietary intake. Primary school age is a critical period for physical growth, cognitive development, and the maturation of organ systems. Nutritional imbalance during this stage may have long-term consequences, including stunting, reduced immune function, and impaired brain development. The aim of this study was to examine the body growth patterns of Awyu and Yaqai girls. This study used a cross-sectional design. Physical growth status was assessed in 163 girls aged 6–12 years at the primary school level, consisting of 84 Awyu girls and 79 Yaqai girls in Mappi Regency, South Papua Province. Nutritional status was determined using the body mass index-for-age (BMI-for-age) index based on anthropometric measurements, including height (cm) and weight (kg), as well as interviews. The results showed that the nutritional profiles of girls from both ethnic groups were not substantially different. Most of the children had a good nutritional status, with 98 children (98.15%) classified as normal, 2 children (1.22%) were classified as overweight, and none were classified as thinness and obese. Keyword : Mappi, girl, cross-sectional, nutritional status
AKTIVITAS ANTIOKSIDAN EKSTRAK HEKSANA, ETIL ASETAT DAN METANOL BIJI KELOR (Moringan oleifera Lamk.) ASAL KABUPATEN MANOKWARI Zaikana Wa Nur Umela Tangadji; Bimo Budi Santoso; Evelina Somar
Jurnal Natural Vol. 21 No. 2 (2025): Jurnal Natural
Publisher : FMIPA Universitas Papua

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30862/jn.v21i2.299

Abstract

ABSTRACT: Antioxidant activity testing of hexane, ethyl acetate (EtOAc), and methanol (MeOH) extracts of M. oleifera seeds was carried out using the DPPH method. The extraction method employed was Soxhlet extraction, which is a type of continuous extraction using an organic solvent at a specific temperature and solvent volume. The yields of each extract were 26.76%, 9.86%, and 39.02%, respectively. The antioxidant activity of the seed extracts was determined based on their IC50 values. Vitamin C was used as a positive control, with an IC50 value of 42.78 ppm. The antioxidant activities of the hexane, EtOAc, and MeOH extracts were 406.09, 399.03, and 135.83 ppm, respectively. The highest antioxidant activity was observed in the MeOH extract, which falls into the category of moderate antioxidant activity. Keywords: Antioxidant, Moringa oleifera seeds, DPPH, hexane extract, ethyl acetate extract, methanol extract
UJI PERFORMA MODUL PELTIER TIPE TEC1-12715 SEBAGAI SISTEM PENDINGIN PADA COOLBOX Lusye Heni Maria Bonggoibo; Tobias T Tukan; Ishak Semuel Erari; Kwasti Kartono Kardiputra; Elohansen Padang
Jurnal Natural Vol. 21 No. 2 (2025): Jurnal Natural
Publisher : FMIPA Universitas Papua

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30862/jn.v21i2.302

Abstract

A Peltier module is a type of Thermoelectric Cooler (TEC) utilized in this study as the cooling system for a coolbox. The objective of this research is to analyze the cooling rate, the lowest achievable temperature, and the performance of the Peltier module by varying the number of modules and the cooling load. The experiment was conducted using variations in the number of Peltier modules (one and two) and variations in the cooling load an empty coolbox and a coolbox containing 1 liter of water. The results indicate that using two Peltier modules accelerates the cooling process and achieves a lower minimum temperature. The lowest temperatures recorded for the empty coolbox were 210C for one module and 19.80C for two modules. For the coolbox containing 1 liter of water, the lowest temperatures achieved were 22.90C for one module and 22.60C for two modules. An increase in the number of modules leads to a greater amount of heat extracted. The heat extracted by one Peltier module in the empty coolbox was 2882.4 J and 3270.1 J for two Peltier modules. In the coolbox containing 1 liter of water, the heat extracted was 22608.55 J for one module and 27418.9 J for two modules. This study also determined the Coefficient of Performance (COP) of the Peltier module system. The COP for the empty coolbox was 4.38% for one module and 3.66% for two modules. Conversely, the COP for the coolbox with 1 liter of water was 2.75% for one module and 2.31% for two modules. The highest COP recorded was 4.38% for one module and 3.66% for two modules, both occurring when the coolbox was empty coolbox (no load).
Perancangan Sistem Pengukuran Suhu dan Kelembapan Ruang Laboratorium Komputer Menggunakan Sensor DHT22 Berbasis Arduino Uno Abdul Muis Muslimin; Aries A Subgan; Sangaji Hasni M. Ipa; Nurul F. Ramadhani Tang; Rosdiana Yoku
Jurnal Natural Vol. 21 No. 2 (2025): Jurnal Natural
Publisher : FMIPA Universitas Papua

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30862/jn.v21i2.306

Abstract

Penelitian ini bertujuan untuk merancang dan mengimplementasikan sistem pengukuran suhu dan kelembapan udara menggunakan sensor DHT22 berbasis mikrokontroler Arduino Uno. Berdasarkan alat pengukuran suhu menggunakan sensor DHT22 berbasis Arduino Uno, data hasil pengukuran suhu dan kelembapan ditampilkan pada layar LCD 16x2. Hasil pengujian menunjukkan bahwa sistem mampu membaca suhu dan kelembapan dengan rata-rata deviasi 0,3°C dan 9,76 % RH dibandingkan alat ukur standar HC520, sehingga layak digunakan untuk aplikasi monitoring suhu ruangan laboratorium berskala kecil, namun untuk pengukuran kelembapan masih perlu dilakukan kalibrasi agar dapat sesuai dengan alat ukur standar.
ANALISIS DINAMIKA MODEL MANGSA-PEMANGSA DENGAN EFEK ALLEE MULTIPLIKATIF PADA MANGSA DAN PEMBAGIAN POPU-LASI PEMANGSA MENJADI KELAS SEHAT DAN TERINFEKSI La Ode Muhlis; Astifan E Matnai; Rium Hilum; Esther Ria Matulessy; Tri Widjajanti Tri Widjajanti; Zulkarnain Zulkarnain; Sabir Sumarna
Jurnal Natural Vol. 22 No. 1 (2026): Jurnal Natural
Publisher : FMIPA Universitas Papua

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30862/jn.v22i1.311

Abstract

This study examines the interaction between prey and predator populations by incorporating a multiplicative Allee effect on the prey and disease infection in the predator. The mathematical model is constructed using a system of differential equations that integrates logistic prey growth, Holling type II functional response, and compartmental dynamics of healthy and infected predators. The analysis was carried out through nondimensionalization, linearization, and equilibrium point determination using the Jacobian matrix to investigate the local stability of the system. The results indicate that the system possesses several equilibrium points representing population extinction, prey-only existence, and coexistence of prey with either healthy or infected predators. The stability of these equilibria is strongly influenced by parameters such as the prey intrinsic growth rate, the Allee threshold, and the disease transmission rate. Numerical simulations demonstrate that the Allee effect can drive the prey population to extinction when its size falls below a critical threshold, while the disease in predators reduces the growth of healthy predators and thus contributes to the persistence of the prey population. This research enriches the field of mathematical ecology by providing new insights into the role of Allee effects and epidemiology in predator-prey dynamics.
Integrasi Penginderaan Jauh dan Sistem Informasi Geografis Untuk Analisis Suhu Permukaan Daratan di Kabupaten Manokwari. Novita Kosamah; Abdul Muis Muslimin; Aries Astradhani Subgan
Jurnal Natural Vol. 22 No. 1 (2026): Jurnal Natural
Publisher : FMIPA Universitas Papua

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30862/jn.v22i1.312

Abstract

The development of urban areas in Manokwari Regency has the potential to reduce the availability of land containing vegetation or Green Open Space (GOS) which may be a contributing factor to increasing land surface temperature that triggers the Urban Heat Island (UHI) phenomenon. This study aims to estimate land surface temperature, analyze its relationship with land cover, and examine the pattern of temperature distribution in the four districts of the study area. The research method integrates remote sensing and Geographic Information Systems, using Landsat 8 OLI/TIRS imagery data, topographic maps, and land cover maps, which were analyzed in GIS through an overlay method and supported by field surveys. The results show that land surface temperatures range from 18.29–30.79°C with an average of 23.23°C and are dominated by the 25–30°C temperature class. Areas with extensive vegetation cover have lower temperatures, whereas residential and built-up areas have higher temperatures. Field surveys at 49 points indicate an average air temperature of 36.25°C with a low correlation to Landsat-derived temperatures (r = 0.34). The areal distribution of high temperatures is, in sequence: West Manokwari District, 2,201.560 ha (28.517%); South Manokwari District, 1,514.092 ha (5.891%); East Manokwari District, 413.156 ha (15.866%); and North Manokwari District, 184.431 ha (0.982%). West Manokwari District is the top priority for mitigating increasing land surface temperature, followed by East Manokwari District and South Manokwari District, through the development of GOS in built-up areas in Manokwari Regency.
ANALISIS MIGRASI KADAR BISFENOL-A (BPA) PADA GALON POLIKARBONAT (PC) KE LARUTAN SIMULAN ETANOL MENGGUNAKAN HPLC DI KABUPATEN MANOKWARI Faizaan Ahmad; Markus Heryanto Langsa; Bertha Mangallo; Aan Sulistiawan Aan Sulistiawan
Jurnal Natural Vol. 21 No. 2 (2025): Jurnal Natural
Publisher : FMIPA Universitas Papua

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30862/jn.v21i2.294

Abstract

Polycarbonate (PC) gallon containers are known to contain Bisphenol-A (BPA), a compound that may migrate into the water and pose health risks, particularly when exposed to high temperatures. This study aims to analyze the migration levels of BPA from No. 7 PC gallon containers into a 20% ethanol simulant solution, reflecting the conditions of products circulated in Manokwari Regency. Samples were incubated at 60°C for two different durations: 2 hours and 10 days. The analysis was performed using High-Performance Liquid Chromatography (HPLC) with a fluorescence detector. The results indicated that incubation time affected BPA migration levels. No BPA migration was detected after 2 hours of incubation; however, after 10 days, BPA was detected at concentrations ranging from 0.007 to 0.017 ppm. Furthermore, an analysis of 18 No. 7 PC gallon samples available in the Manokwari market showed that all samples contained BPA, with concentrations ranging from 0.005 to 0.185 ppm. All detected BPA levels remained below the maximum limit set by the Indonesian National Agency of Drug and Food Control (BPOM Regulation No. 20 of 2019), which is 0.6 ppm.

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