Arabica coffee, one of Indonesia’s economically important coffee commodities, is commonly subject to fraud due to mislabeling and adulteration. In many studies, spectroscopic techniques combined with chemometric methods have been massively employed in classification issues, such as principal component analysis (PCA) and discriminant analyses, compared to machine learning models. In this study, spectroscopy combined with PCA and a machine learning algorithm (artificial neural network, ANN) were developed to verify the authenticity of Arabica coffee collected from four geographical origins in Indonesia, including Temanggung, Toraja, Gayo, and Kintamani. Spectra from pure green coffee were collected from Vis–NIR and SWNIR spectrometers. Several preprocessing techniques were also applied to attain precise information from spectroscopic data. First, PCA compressed spectroscopic information and generated new variables called PCs scores, which would become inputs for the ANN model. The discrimination of Arabica coffee from different origins was conducted with a multilayer perceptron (MLP)-based ANN model. The accuracy attained ranged from 90% to 100% in the internal cross-validation, training, and testing sets. The error in the classification process did not exceed 10%. The generalization ability of the MLP combined with PCA was superior, suitable, and successful for verifying the origin of Arabica coffee.

Sustainable development is development that aims to improve the quality of life for all people around the world, both current and future generations. The focus and alignment of researchers on the theme of sustainable development is highly expected, as evidenced by publications in reputable journals, included in educational journals such as Eurasia Journal of Mathematics, Science and Technology Education (EJMSTE). The purpose of this Systematic Literature Review (SLR) was to review and compare investigations of researches on articles published by EJMSTE so that they are expected to have significant contributions to the topic of sustainable development. This SLR adopts five-step guidelines. The study standards that meet the requirements are, as follows: (i) the data used are from the 2005-2021 publication year; (ii) articles published in English; (iii) full paper can be accessed; and (iv) related to the theme of “sustainable” theme; and (v) only the type of research report articles. It can be concluded that EJMSTE is a pro-sustainable development journal. EJMSTE publishes 22 articles related to the theme of “sustainable”. The most frequently used keywords are sustainable development and sustainability. Dominant authors were from Taiwan and China. We succeeded in formulating four important contributions made by articles published in EJMSTE related to sustainable themes, namely: (i) the urgency of science education in supporting sustainability, ESD, and SDGs funds; (ii) the need for curriculum reform and strengthening the competence of teachers in educational institutions, which are oriented towards sustainability and environmental literacy; (iii) the urgency of using technology that supports sustainability and ESD; and (iv) the urgency of energy efficiency, green marketing, green life cycle, and sustainable tourism to support sustainability. In addition, there are 22 useful educational resources that can be used as references/best practices, which can be implemented at the primary school to higher education levels.

Peningkatan produksi keripik pisang oleh suatu industri tidak lepas dari permintaan proses. Proses pengirisan pisang merupakan proses penentu untuk meningkatkan kapasitas produksi keripik pisang. Permasalahan terjadi pada stasiun pengirisan yang masih sederhana dan dilakukan secara manual. Penggunaan mesin perajang pisang bermaksud untuk agar proses pengirisan pisang lebih mudah dan dapat mempersingkat waktu kerja dengan hasil yang optimum. Penelitian ini bertujuan untuk merancang bangun dan menguji mesin perajang pisang dengan empat pisau horizontal. Perancangan mesin terdiri atas pembuatan model, pemilihan material, perakitan, dan pengujian. Mesin perajang yang berdimensi 480 x 360 x 600 mm dan berat kosong mesin 12 kg memiliki lima komponen utama yaitu unit pemasukan, unit pemotongan, unit pengeluaran, kerangka mesin, sumber dan transmisi daya. Pengujian pada mesin dengan pisang kepok ditetapkan variasi tegangan input motor penggerak antara 75 – 250 volts. Rata-rata slip putaran yang terjadi adalah 3.7%. Putaran pisau dengan kecepatan rendah meningkatkan terjadinya slip. Kapasitas kerja yang dihasilkan untuk merajang pisang adalah 14.2 kg/jam pada tegangan 220 V. Potongan pisang dengan kualitas baik sebesar 77.6% memiliki bentuk bulat dengan tebal rata-rata 2.2 mm, sisanya merupakan potongan pisang yang rusak, berbentuk tidak beraturan, dan hilang karena lengket di dalam mesin. Mesin yang dikembangkan dapat dimanfaatkan oleh industri rumahan yang memproduksi keripik pisang.

The research aimed to examine droplet distribution using a knapsack sprayer with a water level detector-based patternator. The tests consist of measuring spraying discharge, effective spray wide and height, droplet distribution pattern and area, and traveling speed. The sensor calibration showed that the system read the liquid volume in the container with R2 = 0.99 at a linear curve: y = 2.572 + 2.502x. The spray discharge was 0.033 L/s. The optimal spray was at 60 cm-nozzle height with effective spray wide and height were 0.64 m and 0.344, respectively. The spray distribution pattern illustrated that nozzle height affected droplet areas. The traveling speed due to nozzle height at 40 to 70 cm was 0.29 to 0.58 m/s, and had a line-up tendency, whereas spraying capacity was declined 1298 to 562 L/Ha.Keywords: Spray distribution, patternator, sprayer, water level detector

Bedadung stream, located at Rambipuji, Balung, Wuluhan, and Puger, is downstream where dilution of organic wastes occurred and affects its water quality. Microorganisms decompose organic wastes and lead to depletion of dissolved oxygen in the water. The aim of this research was to analyze the deoxygenation rate of Bedadung downstream. The raw data was obtained by measuring stream flows and its water quality parameters (Temperature, DO and BOD) at 5 observed stations. The laboratory analysis consisted of BOD5 and long-term BOD2,4,6,8,10. Increasing the value of BOD for 10 days had a tendency of polynomial pattern order 3 with a coefficient of determination R 0.8987 – 0.9781. The 10 days BOD reactions were used to determine deoxygenation constant K (using least square method) with the result of ranged value 0.043 – 0.372 /day and Ultimate BOD 1.487 – 8.683mg/L. The values of deoxygenation rate at 5 stations were 0.182, 7.997, 7.236, 2.192, and 1.083 mg/L.day. The deoxygenation values were had a similar tendency with the amount of organic waste in the water column and its reduction rate due to the decomposition process.Keywords: Bedadung, BOD, Deoxygenation Rate, DOABSTRAKSungai Bedadung yang terletak di Kecamatan Rambipuji, Balung, Wuluhan dan Puger, merupakan sungai bagian hilir dimana zat pencemar organik bercampur, sehingga mempengaruhi kualitas perairan. Pencemar organik tersebut didekomposisi oleh mikroorganisme perairan sehingga menurunkan DO perairan. Tujuan penelitian ini adalah untuk mengkaji deoksigenasi Sungai Bedadung hilir. Data primer diperoleh dari pegukuran debit dan kualitas air (Temperatur, DO, dan BOD) di 5 (lima) titik pantau. Pengamatan BOD5 dan BOD2,4,6,8,10 dilakukan secara laboratorium. Peluruhan nilai BOD selama 10 hari cenderung memiliki tren polinomial dengan koefisien determinan berada pada nilai 0,8987 – 0,9781. Nilai peluruhan digunakan untuk menentukan nilai K (menggunakan metode least square) dan BOD ultimat. Nilai K di lima titik pantau menunjukkan rentang nilai 0,043 – 0,372 /hari dan BOD ultimat 1,487 – 8,683 mg/L. Sedangkan laju deoksigenasi di lima titik pantau menunjukkan nilai berturut-turut 0,182; 7,997; 7,236; 2,192; dan 1,083 mg/L./hari. Besar nilai deoksigenasi sangat ditentukan oleh banyaknya kandungan pencemar organik dalam air dan kecepatan reaksinya saat proses dekomposisi.Kata Kunci: Bedadung, BOD, Laju Deoksigenasi, DO

Latar Belakang: Sungai Bedadung hilir berada di Kabupaten Jember dan merupakan bagian sungai utama di DAS Bedadung. Sungai ini berperan penting bagi kehidupan masyarakat Jember. Kegiatan pengunaan lahan mengubah fungsi sungai menjadi saluran pembuang limbah. Limbah organik masuk ke badan air Sungai Bedadung dan menurunkan oksigen terlarut di perairan.Metode: Penelitian ini merupakan penelitian deskriptif. Data primer diperoleh dengan melakukan pengukuran debit dan kualitas air (Temperatur, DO dan BOD) sungai di lima titik pantau. Data tersebut kemudian diolah dan digunakan sebagai input variabel persamaan Streeter-Phelps.Hasil: Berdasarkan penelitian yang dilakukan laju deoksigenasi dan reoksigenasi Sungai Bedadung hilir tertinggi berada pada BDG02 masing-masing 7.997 mg/L.hari dan 19.168 mg/L/hari. Purifikasi alami yang dimodelkan dengan persamaan Streeter-Phelps, pada BDG02 tidak menunjukkan tren penurunan oksigen terlarut, sedangkan empat titik yang lain cenderung turun, mencapai kondisi kritis dan saturai di waktu yang berbeda. Hasil pembuktian model menunjukkan terjadi perbedaan nilai DO model terhadap kondisi lapangan (DO aktual).Simpulan: Aplikasi pemodelan Streeter-Phelps untuk menganalisis purifikasi alami Sungai Bedadung tidak dapat menunjukkan kesesuaian dengan kondisi lapang, karena proses deoksigenasi dan reoksigenasi di sepanjang sungai selalu berbeda dengan model bergantung pada tambahan pencemar dan hidraulik sungai. ABSTRACTTitle :Background: Bedadung Downstream, at Jember Region, is the primary river of Bedadung basin. The river has its meaningful advantages to public activities. Change of land uses the stream functions to a big drainage channel. Organic pollutants entrance to the water body and decrease the concentration of dissolved oxygen.Methods: This research was descriptive. The primary data was obtained by measuring stream flows and water quality (Temperature, DO, and BOD) at five observed stations. The data were processed and used as variable inputs to the Streeter-Phelps equation.Results: Based on the research conducted, BDG02 had the highest values of deoxygenation and reoxygenation rates, which were 7.997 mg/L.day and 19.168 mg/L.day respectively. DOmod at BDG02 tends to line up, whereas DOmod at four stations had a tendency to declined to critical conditions and rise to the saturation condition at different times. DO sag model was different from actual DO, which measured directly in the water body.Conclusions: The use of the Streeter-Phelps equation to analyze the self-purification of Bedadung downstream wasn’t appropriate with the field conditions. Deoxygenation and reoxygenation process in the river body was typically difference with the model applied, which were affected by organic pollutants and stream hydraulics.