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Introduction. All educational institutions have to adjust the learning format, from face-to-face to online learning, due to the COVID-19 outbreak. The sudden shifting of the learning format raised several problems for the students and led to mental health issues.Aim. This study aimed to examine the effect of mental health on students’ learning achievement during online learning in the COVID-19 outbreak.Methodology and research methods. This study used partial least square structural equation modelling (PLS-SEM) to examine the research model on a random sample of 518 respondents.Results. The online learning activities during the COVID-19 outbreak have developed mental health issues, such as anxiety and depression. Furthermore, the results indicated that mental health negatively predicted the students’ learning achievement.Scientific novelty. This study reveals certain situations and conditions that could be affected to the student’s mental health and learning achievement.Practical significance. This study can be useful to the government as policymakers and administrators of the university as current research provides a critical understanding of the online learning influence on mental health and learning achievements of students. The government and administrators of the university should consider the right policy for learning activities during the COVID-19 outbreak. The government and administrators of the university also should provide student services to minimise the mental health issues among college students during online learning activities.

Corona Virus Disease-19 (Covid-19) pandemic is still ongoing until now. The spread of this virus is very dangerous because it can spread through droplets or the particles that come out from the nose and mouth. Based on these sentences, the spread of the virus has become risky, one of the activities is shopping online. Virus transmission can occur through delivery and receive stuff activities. The habit that occurs in public, often the stuff arrived at home indirectly sterilized. The purpose of the research is to develop a product that can sterilize the stuff with disinfectant automatically. This research for product development with Ergonomic Function Deployment (EFD) Method. In this method, the product concept is designed based on customer needs (voice of customer). Data of customer needs is obtained from the result of 100 respondents with an age range of 20-40 years who frequently online shopping. The product designed refers to the method used with the ergonomic principle after data is processed. The recommendation of product development from this research is a mini chamber. This product is a development of the chamber but its function is for spraying stuff from the outside of house. The procedure of this product is works automatically so the application of this product for customer can be easier. © 2021 Karadeniz Technical University. All rights reserved.

Post-disaster recovery of marine ecosystems and species is still poorly understood. The Banggai cardinalfish (Pterapogon kauderni) is an ornamental fish endemic to the Banggai Archipelago and a few nearby islands. Classified as Endangered in the IUCN Red List, this fish has limited protected status under Indonesian law. Introduced to several sites in Palu Bay in the early 2000’s, two populations had become established by 2006. Until the triple disaster (earthquake, tsunami, liquefaction) in September 2018, these populations were used for research and education as well as the aquarium trade. The tsunami devastated habitat and microhabitat at the Mamboro site; a census in 2019 found 10 surviving juvenile Banggai cardinalfish in one sea anemone. Monitoring in June 2021 revealed signs of ecosystem recovery, especially seagrass. Despite limited microhabitat with few corals and a lack of Diadema sea urchins, there was a substantial increase in Banggai cardinalfish abundance with all life stages present. New recruits were observed in sea anemones and upside-down jellyfish (Cassiopea sp.). These sites present a natural laboratory for P. kauderni population and post-tsunami ecosystem recovery. Lessons learned can be used to inform conservation management of depleted P. kauderni populations in the endemic range of this endangered fish.

Coffee processing wastewater has a COD of 3100-14343 mg per liter and a BOD of 5000-35000 mg per liter that will cause water pollution and may contaminate the water ecosystem if it is dumped directly into the environment. The literature shows that coffee processing wastewater requires special treatment to reduce the negative impact on the environment. This study develops a wastewater treatment system model capable of identifying sources of emissions and pollutants to increase the effectiveness of pollutant reduction. This study aims to analyse the coffee processing wastewater treatment system, define the most significant attribute, and develop a coffee processing wastewater treatment design using a K-means clustering method. A relief-feature selection method was used to analyze the most significant attribute of coffee processing wastewater related to certain specific wastewater treatment needed. This study used an unsupervised machine learning technique to develop clustering based on the most significant attribute of coffee processing wastewater using the K-Means method. The K-means clustering result shows five coffee processing wastewater treatment clusters based on BOD and Acidity. For clusters with BOD < 25.000 mg per liter: biological and chemical wastewater treatment will be applied through coagulation, adsorption, filtration, bio-filtration, and anaerobic microbial processes to separate pollutants. For clusters with BOD >25.000 mg/l: physical wastewater treatment will be applied through electro-coagulation.

This manuscript presents the investigation of the power weighting of a 3x1 microstrip antenna. The minimum requirement of the proposed antenna is having 200 MHz impedance bandwidth under −10 dB with a working frequency at 5.5 GHz and gain 6 dB or more and the purpose of making this antenna is for Synthetic Aperture Radar (SAR) application. To ensure the antenna design fulfilling all the minimum requirements, double substrate, and various feed-line width techniques are implemented, for example, the antenna is designed with feed-line width 30-ohm impedance, feed-line 50 ohm impedance, feed-line 70 ohm impedance, and for the T-Junction using feed-line width 100-ohm impedance. The proposed antenna is deployed on a 1.6 mm thickness of the NPC-H220A substrate with a dielectric constant of 4.3. The result can achieve a −10 dB reflection coefficient bandwidth of 200 MHz (5.5 GHz) and gain reached 7.98 dB with linear polarization.

Indonesian beef market is very interesting considering the 250 million people residing in the country. In a year, around 670 million kg of beef are consumed; 440 million kg are supplied by local production and 230 million are imported. The price of beef in the Indonesian market (US$ 9.1) is about double that in Australia (US$ 4.2). The high price and the wide margin becomes an appeal for a deeper inquiry. This raises questions such as how does the supply chain look like, how is the distribution of the wide margin from importers to retailers, does corruption still exist due to the import licensed, and who really enjoys the profit. This study aims to analyze the supply chain of beef industry and the factors affecting meat prices in Indonesia. The data was collected through a survey of 134 respondents in seven districts and cities in Surakarta, Indonesia followed by in-depth interviews with breeders, slaughters, wholesalers, retailers and consumers. The results show that factors affecting meat prices are the bargaining power of several actors in the supply chain and the market structure discussed in this paper.

This paper is concerning how the technical study of the 145 MWac Cirata solar Floating construction was built on the cirata dam. The Cirata floating solar power plant development plan starts with the Renewable Energy Mix target set by the Indonesian government as stipulated in the National Electricity General Planning Document 2018-2037 with a target of 23% renewable energy by 2025. Technical aspects of the study are carried out on several aspects such as availability land which will determine the type of PV Land Base or floating. with some technical considerations while eventually floating technology was chosen since has technical and financial advantages for the construction of solar power plants in this location. Subsequently, an evaluation was carried out to determine the potential for irradiation at the specific locationbju. After obtaining irradiation data and meteorological conditions, a projection of energy production in the location is carried out using the performance ratio parameters on several values to obtain the projection of annual energy production. An evaluation of interconnection was also carried out to find out whether the construction of the 145 MWac floating solar was safe against the reliability of the 150 kV and 500 kV systems in the West Java system.

The following paper presents the first published record of the cryptic Borneo Earless Monitor (Lanthanotus borneensis Steindachner, 1877) from West Kalimantan (Indonesian Borneo). This sole member of the family Lanthanotidae is endemic to Borneo. Since its description in 1877, all locality records of specimens refer to Sarawak (Malaysian Borneo). The recent discovery of this “living fossil” in an oil palm estate under development in Landak District expands its known distribution southward to Kalimantan. This paper (i) describes the circumstances of the discovery, characteristics of the individual and microhabitat structure in which it was found, (ii) provides results from local community interviews about the local distribution of the species, suggesting it is found more broadly in the Landak District and possibly elsewhere, and (iii) places this information in a broader context of current knowledge and high conservation value of L. borneensis.

This is a case study on using a DSP board to construct an encryption/decryption module embedded in a e-commerce Web server. The idea of using DSP is to push beyond the key length limits of encryption/decryption algorithms and computational power in a software environment while avoiding the heavy investment in a dedicated hardware encryptor/encryptor. The low cost, high computational power, high flexibility of DSP and the ubiquitous availability of a PC peripheral component interconnect slot for the DSP can provide any Web browser or Web server an excellent cost-effective option to improve the security level of Internet applications. The paper provides a step-by-step procedure and reveals every detail of a successful implementation of a DSP RSA encryptor/decryptor for an e-commerce Web server by using the latest TMS320C6000/sup TM/ Evaluation Module (EVM) DSP hardware. A strong prime concept and Garner algorithm are introduced to generate more secure keys and compute encryption/decryption more efficiently than that of recent publications. Experiments show that the performance of using DSP hardware encryption can be 300 times faster than that in software environment.