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Jurnal Natural
Published by Universitas Syiah Kuala
ISSN : 14118513     EISSN : 25414062     DOI : https://doi.org/10.24815/jn
Core Subject : Science, Agriculture,
Agriculture, Biological Sciences & Forestry Astronomy Biochemistry, Genetics & Molecular Biology Chemistry Earth & Planetary Sciences Energy Immunology & microbiology Neuroscience Physics
Jurnal Natural (JN) aims to publish original research results and reviews on sciences and mathematics. Jurnal Natural (JN) encompasses a broad range of research topics in chemistry, pharmacy, biology, physics, mathematics, statistics, informatic and electronic.
Arjuna Subject : Matematika - Matematika (Lain-Lain)
Articles 9 Documents
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Search results for , issue "Volume 23 Number 1, February 2023" : 9 Documents clear
Empirical model for the estimation of global solar radiation in the Aceh Besar Regency, Aceh MUHAMMAD IRFAN ISLAMI; NAZLI ISMAIL; ISMAIL ISMAIL; DEA RIMASILANA
Jurnal Natural Volume 23 Number 1, February 2023
Publisher : Universitas Syiah Kuala

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24815/jn.v23i1.28697

Abstract

Solar energy plays an important role in the temperature distribution on the Earth's surface and essential energy that sustains life for human. In the calculation of solar energy, the limitation of solar radiation data is a major obstacle. Solar radiation data is very limited at some observation stations due to the costly procurement of measuring instruments and complicated techniques. Estimation of global solar radiation using empirical models is one way to overcome the limitations of global solar radiation data at various locations. This study built the Angstrom-Prescott model to estimate global solar radiation based on the sunshine duration’s parameter in Aceh Besar Regency. Two years (2019-2020) global solar radiation and sunshine duration data from Aceh Climatological Station were used to estimate global solar radiation in 2021. Data for 2021 was using to evaluated the equation H/H0=0.28+0.22 (n/N), the results showed good model accuracy with an RMSE value of 0.052 and a MAPE of 11% (good forecasting). The model equation has been reliable to calculate solar radiation in four locations in Aceh Besar Regency.
Daily behavior and interaction of cats (Felis catus) with humans at a canteen in IPB University LIZA MAHERA; ASTUTI LATIF; SITI SARI AZYATI; HANNY RAMADHANTI; KANTHI ARUM WIDAYATI
Jurnal Natural Volume 23 Number 1, February 2023
Publisher : Universitas Syiah Kuala

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24815/jn.v23i1.26515

Abstract

Understanding feral cat behavior can be one of the aspects that is necessary for proper management and taking policy action in controlling the cat population. This study aimed to observe the daily activities of feral cats and see the correlation between the number of visitors on cat-to-human interaction at a canteen in IPB University. Observation of cat’s daily behavior was conducted by scan sampling method and cats’ interaction with humans was conducted by ad libitum sampling. Our results showed that self-care (66.27%) dominated the daily behavior of cats followed by negative behavior (20.83%) and affiliative behavior (12.9%). Correlation test showed there was a significant negative correlation between the number of visitors and frequency of affiliative behavior (p = 0.024). The number of visitors also shows a positive correlation to self-care (p = 0.034). No significant correlation between the number of visitors and negative encounters behavior (p = 0.27). The highest frequency value of cat-human interaction was approaching human (A) 28.15%, followed by vocalization (MV) 28.15% and eye contact (KM) 22.71%. Cat-human interaction behavior did not significantly correlate with the number of visitors (p 0.05). Our result implies that the feral cat’s use the canteen as a place to rest, not a place to find food and daily activities and human-cat interactions were specific for each study site. Therefore, in the management of feral cats, it was necessary to pay attention to the conditions of their respective habitats.
Isolation and characterization of polyhydroxyalkanoate (PHA) producing bacteria isolate from landfill land of Kampung Jawa Banda Aceh MAZWAN MAZWAN; FEBRIANI FEBRIANI; NAZARUDDIN NAZARUDDIN
Jurnal Natural Volume 23 Number 1, February 2023
Publisher : Universitas Syiah Kuala

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24815/jn.v23i1.29746

Abstract

The production of biodegradable plastic from microorganisms has great potential as a substitute for conventional plastic. This study aims to isolate bacterial strains capable of polyhydroxyalkanoates (PHAs) production from the Kampung Jawa landfill land (KJLL) and characterize biopolymers. The bacterial strains were able to produce PHA using a mineral salt medium (MSM) with glucose as a carbon source. The qualitative screening of PHA-producing bacteria was conducted by Sudan Black and Nile Red. Of the 64 bacteria strains, only 41 were able to accumulate PHA in Sudan Black and Nile Red. The results showed that one bacteria the Coccobacillus strain had the highest color intensity for further characterization of PHA. The characterization of PHA by Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA) showed a melting temperature (Tm) of 101.54°C. X-ray diffraction (XRD) analysis revealed a crystalline structure with an index crystallinity (ICr) value of 15.82% for PHA. The results of the analysis proved that PHA was produced by bacteria isolate. This study suggests that this is the first report of the bacteria from the Kampung Jawa landfill producing PHA with good characteristics and potential biotechnology applications. 
Application of Poisson and negative binomials models to estimate the frequency of insurance claims RINI OKTAVIA; RAHMA ZUHRA; HAFNANI HAFNANI; NURMAULIDAR NURMAULIDAR; INTAN SYAHRINI
Jurnal Natural Volume 23 Number 1, February 2023
Publisher : Universitas Syiah Kuala

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24815/jn.v23i1.26623

Abstract

Generalized Linear Models (GLMs) are a modeling approach that allows the modeling of nonlinear behaviors and non-Gaussian distributions of residues. This approach is very useful for general insurance analysis, where the frequency of claims and the amount of claims distributions are usually non-Gaussian. In this article, the application of Poisson and Negative Binomial models to estimate the frequency of claims of auto insurance is discussed. The accuracy of the models was compared to choose the best model for determining pure insurance premiums using R software. The data used are a secondary dataset which is the motor vehicle insurance dataset from Sweden named dataOhlsson and the motor vehicle dataset from Australia named ausprivauto0405. The results of the exploration of the GLMs model are that Poisson's GLM and Negative Binomial models both are suitable models for estimating the number of claims for the dataOhlsson dataset. Both models have relatively similar parameter estimates, as well as the AIC and BIC values for the dataOhlsson dataset, however, both models are not suitable for estimating the number of claims for the ausprivauto0405 dataset. More investigation using different models is needed to ensure which model is more appropriate for estimating the frequency of insurance claims.
Thermal and physical properties of CNF/glutaraldehyde-gelatin-based hydrogel ROSLIANA LUBIS; SRI WAHYUNA SARAGIH; WARDATUL HUSNA IRHAM; AJMAIN AJMAIN; SAISA SAISA
Jurnal Natural Volume 23 Number 1, February 2023
Publisher : Universitas Syiah Kuala

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24815/jn.v23i1.29935

Abstract

The use of hydrogel as a wound dressing material is currently being massively developed. In addition to functioning to protect wounds, the use of hydrogel can also provide moisture in a measured manner and can be used as a drug delivery medium. In this study, hydrogel based on CNF and glutaraldehyde crosslinking agent and addition of gelatin were developed with various compositions 0.25; 0.5; 0.75 g to increase the ability of CNF and hydrogel to absorb water so that it is good to be applied as a wound dressing. The composting of the three materials aims to obtain a hydrogel with good thermal and physical properties. Based on physical character for a good ratio of swelling (666,62%) and degree of cross-linking (94%) on the hydrogel with a composition variation of 0.5 g of CNF addition. For the thermal stability of hydrogel var 2, TMax 591oC provides better thermal stability than var 1 and var 3. The morphology of hydrogel shows very small and evenly distributed pores on the surface which can absorb more water.
Isolation of active compound as anti acne from ethanol extract Artocarpus camansi leaves AZALIA IZDHIHAR AZWAR; MUHAMMAD BAHI; ROSNANI NASUTION; NURDIN NURDIN; MARIANNE MARIANNE
Jurnal Natural Volume 23 Number 1, February 2023
Publisher : Universitas Syiah Kuala

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24815/jn.v23i1.27036

Abstract

Acne vulgaris or acne is a chronic inflammatory skin disease in adolescents and adults affecting one self-confidence. The result of the research shows the ethanol extract, subfraction, pure isolate, and gel extract of Artocarpus camansi are active in inhibiting the growth of Propionibacterium acnes. The ethanol extract with the highest inhibition zone was at the concentration of 0.5 and 2% with 9.1±0.62 mm and 8.5±0.7 mm with the activity of 47.07% and 43% respectively (in comparison with the chloramphenicol 30 μg 19.33±0.47mm). The gel extract had the highest activity at 2%, with an inhibition zone of 8±0.50 mm and the activity of 43.97%. Anti-acne activity for all subfractions had an activity of 32.5-33.3% while the pure isolate was at 42.10 - 45.63%. Physical properties of the gel extract were evaluated for four weeks by examining the pH test obtained with a range of 5.8-6.7, viscosity in the range of 18460-19668 cP, spreadability in the range of 5.45-7.20 cm, adhesion observation above 4 seconds, and homogeneity in a concentration of 0.5-7.5%. The pure isolate has a melting point of 147 ℃, presumed to be γ-sitosterol and appropriate with the screening phytochemicals results with the presence of steroid.
Antiseptic activity assay of ethanolic extract of Aceh’s rambutan rind (Nephelium lappaceum L.) against Staphylococcus aureus and its formulation as hand sanitizer gel IRMA SARI; MEUTIA FARADILLA; RISKA ANANDA PUTRI
Jurnal Natural Volume 23 Number 1, February 2023
Publisher : Universitas Syiah Kuala

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24815/jn.v23i1.20412

Abstract

The hands are one of the most susceptible parts of the human body to bacterial infection. One way to maintain health is to maintain hand hygiene. Ethanolic rambutan rind extract from Aceh province has been studied in order to determine if it can inhibit bacterial growth. This research was conducted to determine the antiseptic activity of the ethanol extract of rambutan rind against Stahpylococcus aureus by determining the phenol coefficient and determining whether the ethanolic extract of Aceh’s rambutan rind can be formulated into a hand sanitizer gel. Antiseptic activity testing was performed using the Rideal-Walker method which was carried out in 5 dilutions (1:100, 1:150, 1:200, 1:250 and 1:300). The absorbance measurement showed that the extract could act as an antiseptic, at a concentration of 1% and at a dilution of 1:200 which has phenol coefficient of 1.67. The ethanolic extract of Aceh’s rambutan rind can be formulated in the form of a hand sanitizer gel using 1% Carbopol as gelling agent. The results showed that the gel was brown with a distinctive menthol odor and changed into a dark brown color after a cycling test. The evaluation results of all formulas appropriated the requirements except for adhesion parameter. The results of the irritation test showed that the volunteers did not experience any signs of irritation. The results of the preference test showed that the respondents liked the shape and aroma parameters but not the color parameter.
The effect of brewing time herbal tea from mother-in-law’s tongue leaves (Sansevieria trifasciata Prain) on total phenol, total flavonoid, and antioxidant activity MAYA PRATIWI HUTABARAT; ZULKIFLI LUBIS; JANSEN SILALAHI
Jurnal Natural Volume 23 Number 1, February 2023
Publisher : Universitas Syiah Kuala

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24815/jn.v23i1.28329

Abstract

Indonesia is a tropical country known for its biodiversity, one of which is the mother-in-law’s tongue (Sansevieria trifasciata Prain). Mother-in-law’s tongue leaves extract contains bioactive compounds, such as triterpenoids, steroids, and flavonoids and tradionally used especially as antidiabetics. The phenolic and flavonoid compounds in mother-in-law’s tongue are potential antioxidants, and usually processed into herbal tea. This research aimed to determine the effect of duration brewing time herbal tea from mother-in-law’s tongue leaves (Sansevieria trifasciata Prain) on total phenol, total flavonoid, and antioxidant activity. This study using Completely Randomized Designed (CRD) with 5 treatments (different brewing time that were 1, 3, 6, 9, 12 minutes) and 3 replications. The result showed that brewing time had a significant effect on total phenol, total flavonoid, and antioxidant activity.  The optimum of brewing time herbal tea from mother-in-law’s tongue leaves is 6 minutes.
Study on the performance of Robust LASSO in determining important variables data with outliers ROCHYATI ROCHYATI; KUSMAN SADIK; BAGUS SARTONO; EVITA PURNANINGRUM
Jurnal Natural Volume 23 Number 1, February 2023
Publisher : Universitas Syiah Kuala

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24815/jn.v23i1.26279

Abstract

A variable selection method is required to deal with regression models with many variables, and LASSO has been the most widely used methodology.  However, as several authors have noted, LASSO is sensitive to outliers in the data.  For this reason, the Robust-LASSO approach was introduced by applying some weighting schemes for each sample in the data.  This research presented a comparative study of the three weighting schemes in Robust LASSO, namely Huber-LASSO, Tukey-LASSO, and Welsch-LASSO.  The study did a rich simulation containing many scenarios with various characteristics on the covariance structures of the explanatory variable, the types of outliers, the number of outliers, the location of active variables, and the number of variables.  The study then found that Tukey-LASSO outperformed Huber-LASSO and Welsch-LASSO in identifying significant variables.  The Robust LASSO performance generally decreased as the covariances among explanatory variables increased and the data dimension increased.  Exploration of sembung leaf extract data shows that the data is high dimensional data which contains outliers of about 14,28% on the response variable and about 25,71% on the explanatory variables.  Based on the research, the number of variables selected using the Tukey-LASSO method was nine compounds, Huber-LASSO and Welsch-LASSO were eight compounds, and LASSO 13 compounds.  The Tukey-LASSO prediction accuracy is superior to the other three methods.

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