Sainmatika: Jurnal Ilmiah Matematika dan Ilmu Pengetahuan Alam <p><strong style="text-align: justify; font-size: 0.875rem;"><a href=""><span style="vertical-align: inherit;">Sainmatika</span></a><span style="vertical-align: inherit;"> : Jurnal Ilmiah Matematika dan Ilmu Pengetahuan Alam </span></strong><span style="text-align: justify; font-size: 0.875rem;"><span style="vertical-align: inherit;">with registration number </span><strong style="text-align: justify; font-size: 0.875rem;"><span style="vertical-align: inherit;">ISSN </span><a href=""><span style="vertical-align: inherit;">1829 586X</span></a><span style="vertical-align: inherit;"> (print)</span></strong><span style="vertical-align: inherit;"> dan </span><strong style="text-align: justify; font-size: 0.875rem;"><span style="vertical-align: inherit;">ISSN </span><a href=""><span style="vertical-align: inherit;">2581-0170</span></a></strong><strong style="text-align: justify; font-size: 0.875rem;"><span style="vertical-align: inherit;"> (online)</span></strong><span style="vertical-align: inherit;"> is a scientific journal managed and published by the Faculty of Science and Technology, PGRI University Palembang.</span></span><span style="text-align: justify; font-size: 0.875rem;"><span style="vertical-align: inherit;"> Sainmatika publishes research articles from laboratory or field experiments as well as theoretical and elaborative research in the field of Basic Sciences; Mathematics, Chemistry, Physics and Biology. The journal accepts articles in Indonesian or English. The journal is published twice a year in June and December. Sainmatika has also been accredited by the Indonesian Ministry of Research, Technology, and Higher Education and indexed in SINTA with the S3 category. This journal has also been registered in the Crossreff system with Digital Object Identifier </span></span><a style="text-align: justify; background-color: #ffffff; font-size: 0.875rem;" href=""><span style="vertical-align: inherit;">10.31851/sainmatika </span></a><span style="text-align: justify; font-size: 0.875rem;"><span style="vertical-align: inherit;">starting Vol 15 No 1 June 2018.</span></span></p> <div class="deskripsi"> <table cellpadding="2"> <tbody align="top"> <tr> <td width="100px">Journal Title</td> <td><strong><span style="vertical-align: inherit;">Sainmatika: Jurnal Ilmiah Matematika dan Ilmu Pengetahuan Alam</span></strong></td> </tr> <tr> <td>ISSN</td> <td><strong><strong><a href=""><span style="vertical-align: inherit;">2581-0170</span></a> (online)|<a href=""><span style="vertical-align: inherit;">1829 586X</span></a> (print)</strong></strong></td> </tr> <tr> <td>Frequency</td> <td><strong><span style="vertical-align: inherit;">2 edition per year (June, December)</span></strong><a href=";q=halaman%20olahraga%20nusantara" target="_blank" rel="noopener"><strong><img src="" alt="" /></strong></a></td> </tr> <tr> <td>DOI</td> <td><strong><a id="pub-id::doi" href=""><span style="vertical-align: inherit;">10.31851/sainmatika</span></a></strong></td> </tr> <tr> <td>Publisher</td> <td><strong><span style="vertical-align: inherit;">Universitas PGRI Palembang</span></strong></td> </tr> <tr> <td>Subject Area</td> <td><strong><span style="vertical-align: inherit;">Basic Science; Mathematic, Chemistry, Phisics, Biology</span></strong></td> </tr> <tr> <td valign="top">Indexing</td> <td><strong><span style="vertical-align: inherit;">Google Scholar | Dimension |SINTA | Others</span></strong></td> </tr> </tbody> </table> </div> <div id="content"> <div> </div> </div> Universitas PGRI Palembang en-US Sainmatika: Jurnal Ilmiah Matematika dan Ilmu Pengetahuan Alam 1829-586X <div>Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a <span> </span><a href="" target="_blank">Creative Commons Attribution 4.0 International License</a> that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.</div><div><a href="" rel="license"><img src="" alt="Creative Commons License" /></a></div> Effect of Tomato Juice Volume on Coagulation Time and Latex Weight <p>Natural latex clumping takes longer than using chemicals. Another alternative is needed to coagulate the latex by adding acid from natural ingredients. Tomatoes (<em>Lycopersicum esculentum</em> Mill) have 29.32 mg of ascorbic acid and 0.54 g of citric acid every 100 grams, they have the potential to be used as a natural latex coagulator. The research method add tomato juice to fresh latex to break down the emulsion and form rubber lumps. After mixing, the weight of the latex is weighed. The constant variables are the latex volume of 10 ml, and the tomato juice volume of 5,10,20,30,40,50,60,70,80,90 and 100 ml respectively. The higher the volume of tomato juice, the faster it will clot. The best volume of tomato juice is 100 ml with a clumping time of 52 minutes. Increasing the volume of tomato juice increased the weight of latex to 13.1 grams and reduced the pH of latex to 4.9. Giving tomato juice every 5 ml accelerated clumping up to 360 minutes (6 hours) compared without tomato juice.</p> Dewi Putri Yuniarti Surya Hatina Nidya Afriyani Copyright (c) 2023 2023-10-19 2023-10-19 20 2 96 101 10.31851/sainmatika.v20i2.11322 Reproductive Biology of Striped Snakehead (Channa striata, Bloch, 1793) in Floodplain of Lubuk Lampam, South Sumatra <p>Striped Snakehead (Channa striata) is one of the fish species inhabiting the flooded floodplain. Currently, the striped snakehead fish population in the Lubuk Lampam floodplain is undergoing a significant decline due to continuous and unregulated fishing activities. To prevent this population decline, there is a need for comprehensive efforts in managing their reproduction. The objective of this study was to investigate the reproductive behavior of striped snakehead fish in the floodplain of Lubuk Lampam, South Sumatra. The research spanned five months, from December 2022 to April 2023, and involved the collection of fish samples from four different floodplain types: river, lebung, lebak kumpei, and rawang. A total of 284 striped snakehead fish were examined, and measurements of length- weight and their reproductive biology were observed. The findings revealed that the sex ratio of striped snakehead fish was skewed toward females, with a ratio of 1:1.7 (females to males). The size at which female striped snakehead fish reach maturity was determined to be 28.5 cm, while male striped snakehead fish matured at 29.30 cm. The peak spawning season for striped snakehead fish occurred in December, coinciding with the rainy season. The spawning grounds for striped snakehead fish were predominantly located in the lebung station in the upper reaches of the Lubuk Lampam Floodplain. Striped Snakehead fish exhibited a partial spawning behavior. Furthermore, these fish demonstrated a relatively high reproductive potential, with fecundity ranging from 5,859 to 30,321 eggs.</p> Khoirul Fatah Etty Riani Hurip Pratomo Copyright (c) 2023 2023-10-20 2023-10-20 20 2 102 113 10.31851/sainmatika.v20i2.12828 Antioxidant Activity of Endophytic Fungi Extract Isolated from Peel of Pineapple (Ananas comosus (L.) Merr. ‘Prabumulih’)) <p>Pineapple (<em>Ananas comosus</em> (L.) Merr. 'Prabumulih') is a tropical fruit that is very popular for its unique aroma and sweet taste. It is also commonly believed that this fruit has potential applications in traditional medicine. However, the peel is not fully harnessed, despite its rich and intricate composition. This study presented findings regarding the endophytic fungi discovered within the peel of A comosus (L.) Merr. 'Prabumulih' and their performance as antioxidants. The endophytic fungal species were identified based on their morphological characteristics. The antioxidant assessment was carried out using the DPPH method. According to the findings of morphological identification, <em>Trichoderma harzianum</em>, an endophytic fungus, was found to exhibit the highest potential as an antioxidant source. Antioxidant activity showed a very strong category (IC<sub>50</sub> = 18.74 µg/mL). Through the isolation of its pure constituents and subsequent in vivo testing, there is the potential for this extract from the endophytic fungus to evolve into an innovative source of antioxidants.</p> Rian Oktiansyah Yustina Hapida Sinta Risasti Copyright (c) 2023 2023-11-13 2023-11-13 20 2 114 125 10.31851/sainmatika.v20i2.13270 The Locating Chromatic Number for Pizza Graphs <p>The location chromatic number for a graph is an extension of the concepts of partition dimension and vertex coloring in a graph. The minimum number of colors required to perform location coloring in graph <em>G</em> is referred to as the location chromatic number of graph <em>G</em>. This research is a literature study that discusses the location chromatic number of the Pizza graph<em>.</em> The approach used to calculate the location-chromatic number of these graphs involves determining upper and lower bounds. The results obtained show that the location chromatic number of the pizza graph is 4 for <em>n</em> = 3 and <em>n</em> for ≥ 4.</p> Nurul Maulida Surbakti Dinda Kartika Hamidah Nasution Sri Dewi Copyright (c) 2023 2023-11-25 2023-11-25 20 2 126 131 10.31851/sainmatika.v20i2.13085 Lead Contamination in Driver's Blood and Its Effects on Erythrocytes, Leukocytes, and Platelets as A Biomarker <p>Lead as a component of air pollution has broad toxic effects and can be detrimental to humans, such as causing abnormalities in kidney function, digestive tract, nervous system, and hematopoietic disorders. Many people carry out their activities on the highway, one of which is an Angkot driver. Drivers who work on the road daily get direct exposure to air pollution, especially from lead (Pb). Therefore they are very vulnerable to the negative effects of lead (Pb). This study aimed to measure blood lead levels as a biomarker of lead contamination in a driving group in Palembang City. The subjects were drivers who had been working for more than 20 years (average 28 years) and the average age was 58 years. Testing blood lead levels using the APHA method and examining erythrocytes leukocytes and platelets using the impedance method and correlation test using the Spearman test. Based on the results of this study, there is a relationship between blood lead levels and erythrocyte (significance: 0.0019) and leukocyte (significance: 0.002) values, but there is no relationship between blood lead levels and platelet values (significance: 0.4), while blood lead levels in drivers are still within the threshold limit (average: 14.9804 µg/L).</p> Pra Dian Mariadi Agnes Felicia Lubis Lidwina Septie Ch Copyright (c) 2023 2023-11-25 2023-11-25 20 2 132 139 10.31851/sainmatika.v20i2.13010 The Effect of Carbon on Chitosan-ZnO Composites as Fabric Mask Coating Materials <p>Increasing the effectiveness of cloth masks can reduce the use of disposable medical masks which creates a new waste problem. In this research, the synthesis of zinc oxide nanoparticles was carried out using the precipitation method through the reaction between zinc nitrate and phosphoric acid as one of the ingredients in the chitosan-ZnO/C composite mixture. The carbon source is obtained from activated coconut shell carbon using sodium hydroxide. X-ray diffractometer (XRD) testing was carried out to determine the phase content of the synthesized carbon powder. XRD testing was also carried out on synthesized ZnO particles to determine the occurrence of phase transformations and to determine the quantitative and qualitative characteristics of the material. Fourier Transform Infrared testing was also carried out to observe functional group bonds formed in carbon compounds. Composite materials that have been successfully made will then be tested for hydrophobicity by calculating the contact angle. The results of this study indicate that the synthetic base material has been successfully carried out and the composite has been successfully made. The highest water contact angle is 106<sup>o</sup> was found in the chitosan/ZnO composite sample with a ratio of 2:1 and a mass variation of 0.05 gr active carbon.</p> Metatia Intan Mauliana Yulian Findawati Galuh Ratmana Hanum Copyright (c) 2023 2023-11-27 2023-11-27 20 2 140 146 10.31851/sainmatika.v20i2.12651 Identification and Counting of Bacterial Colonies on Mobile Phones Before and After 70% Alcohol Disinfection <p>Cell phones have become a very important communication tool in everyday life. Considering that many people are in the habit of using their mobile phones while doing other activities, most people even have the habit of taking their phones to the toilet. Cell phones become inanimate objects that play an important role in the transmission of microorganisms. Therefore, we need to maintain hand hygiene by keeping our hands clean after handling the mobile phone before performing activities and disinfecting the mobile phone regularly, considering that this object cannot be washed while the mobile phone is a potential vector for infectious diseases. Mobile phones can effectively eliminate hand hygiene due to their compulsive use despite hand washing. The purpose of this study was to determine the role of 70% alcohol cotton on the surface of mobile phones to reduce the potential spread of bacteria. Based on the results of the research conducted, there is a difference in the number of bacterial colonies on mobile phones before and after disinfection with 70% alcohol cotton, as evidenced by the obtained p-value of 0.0001 (p &lt;0.05).</p> Mustika Sari Hutabarat Hotman Sinaga Copyright (c) 2023 2023-11-29 2023-11-29 20 2 147 156 10.31851/sainmatika.v20i2.13128 Topography Effects on Rainfall Characteristics in Bandung City and Cilacap Regency for the 2016-2020 Period <p>Topography and rainfall correlate with each other. Therefore, this study aims to determine the effect of topography on rainfall characteristicss in the Cilacap and Bandung areas. The research method used is a descriptive statistical analysis of average monthly, seasonal, and annual rainfall. In addition, time series and regression tests were carried out using the SPSS application. The data used is the daily rainfall data period of 2016–2020. The results of the descriptive analysis show that the variability of monthly rainfall in Bandung is higher than in Cilacap, with a value range that is 113.6–643.82 mm/month for Bandung and 92.1-355.56 mm/month for Cilacap. Global climate dynamics for instance apparent sun motion, Monsoon, ITCZ, ENSO, and IOD, as well as local weather systems like valley winds, also affect seasonal and annual rainfall variability in Bandung and Cilacap. The rainfall time series test produces values that are not stationary concerning the variance but stationary concerning the average. A simple linear regression test shows the effect of a topography of 55.2% on rainfall. The purpose of simple linear regression is to understand and model the relationship between two variables: the independent variable (topography) and the dependent variable (rainfall characteristics).</p> Fadhli Aslama Afghani Imawan Mashuri Ramadoni Khirtin Muhammad Adi Cahyo Copyright (c) 2023 2023-11-29 2023-11-29 20 2 157 167 10.31851/sainmatika.v20i2.11898 Exploration of Patellidae from Coastal Waters of Ambon Island, Indonesia <p>Patellidae are gastropods that live in intertidal zones and sublittoral zones of shallow rocky shores because Patellidae are usually attached to boulders. Patellidae belongs to the order Archaeogastropoda and generally only has two genera, namely Cellana and Patella. Patellidae are also found in the waters of Ambon Island, namely in the Hukurila Village and Allang Village. This study aims to determine the type, morphometrics, density, and proximate levels of Patellidae in the waters of Ambon Island. Samples were taken using purposive sampling with cruising methods. The Patellidae are attached to the substrate. Samples from two locations were taken and put into plastic, and then the type and morphometrics were identified at the Basic Biology Laboratory of the Faculty of Teacher Training and Education, Pattimura University. Proximate levels were conducted at the Basic Chemistry Laboratory, Faculty of Mathematics and Natural Sciences, Pattimura University. This research was conducted from October 15, 2022, to November 15, 2022. Based on the results, two species of the Patellidae family were found in Ambon Island, namely <em>C. testudinaria</em> and <em>P. flexuosa</em>. The results of the calculation of morphometric Patellidae in the Waters of Ambon Island showed that the species <em>C. testudinaria</em> in the Waters of Hukurila Village has a larger morphometric characteristic size compared to the species <em>C. testudinaria</em> and <em>P. flexuosa </em>in the Waters of Allang Village. More individuals of <em>P. flexuosa</em> species were found in Alang village than <em>C. testudinaria</em> species, while many <em>C. testudinaria</em> species were found in Hukurila village. Based on the proximate analysis results, Patellidae from the waters of Ambon Island have nutritious and good nutritional content to be used as food ingredients.</p> Dwien E. Pattipeilohy Sintje Liline Sriyanti A.I Salmanu Tri Santi Kurnia Copyright (c) 2023 2023-12-02 2023-12-02 20 2 168 175 10.31851/sainmatika.v20i2.12736 Comparison to the Iron Level on the well water and PDAM water sample using ICP-OES Spectrophotometer <p>Iron (Fe) is one of the elements that can be found in almost every place on earth, in all geological levels, and in all water bodies. In general, the iron in the water can be dissolved. The content of <em>Fe</em> ions in drilled well water can range between 5-7 mg/L. ICP-OES spectrophotometry is a type of ICP that utilizes plasma as a source of atomization and excitation. The purpose of this research is to determine the difference in <em>Fe</em> content between well water samples and PDAM water samples in the Pemulutan sub-district using the ICP-OES spectrophotometer. The type of research used was cross-sectional. The population in this study was well-watered and PDAM-watered in Pemulutan District. The sampling technique in this study was simply random. The place of this research was in the Palembang Health Laboratory Center. The results showed that the average difference in the examination of <em>Fe</em> levels in well water samples and PDAM water using the sda was 0.13198 mg/L for well water and 0.00445 mg/L for PDAM water. The conclusions were that PDAM water is safer to use for sanitation activities or consumption purposes than well water. The iron (Fe) content in well water is higher than the iron (Fe) content in PDAM water.</p> Alya Melanisya Fadhilah Nurhidayanti Denny Juraijin Copyright (c) 2023 2023-12-02 2023-12-02 20 2 176 182 10.31851/sainmatika.v20i2.12991