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This research investigates intelligent cooling system design for main ship engines operating in tropical waters, integrating advanced machinery engineering with human factors to address thermal management challenges affecting engine performance, reliability, and crew operational effectiveness. Tropical maritime environments impose severe cooling demands through elevated seawater temperatures (28-32°C), high ambient conditions (28-35°C), and accelerated biofouling, reducing conventional cooling system effectiveness by 15-25% while increasing maintenance burdens and operational risks. Through qualitative analysis involving marine engineers, chief engineers with tropical operational experience, cooling system manufacturers, naval architects, automation specialists, and maritime training institutions, this study examines how intelligent cooling systems incorporating variable-speed pumps, adaptive control algorithms, predictive maintenance, and crew-centered interfaces can optimize thermal management while supporting effective human-machine collaboration. Results demonstrate that intelligent systems can reduce cooling energy consumption by 20-35%, improve temperature stability by 50-65%, extend maintenance intervals by 40-80%, and enhance crew situational awareness through intuitive monitoring interfaces, while requiring comprehensive training programs developing technical understanding and operational competencies. Key implementation challenges include control system complexity, sensor reliability in harsh marine environments, integration with existing engine management platforms, crew competency development requirements, and lifecycle cost justification. Findings reveal that successful intelligent cooling system implementation requires holistic sociotechnical approach addressing machinery engineering optimization, automation technology deployment, and human capability development through coordinated design and training strategies. This research contributes to marine engineering literature by providing integrated frameworks for intelligent system design incorporating machinery performance, automation capabilities, and human factors supporting operational excellence in tropical maritime operations.

Tuna fisheries are a strategic sector in Indonesia's fishing industry, contributing significantly to the national economy. Albacore tuna (Thunnus alalunga) has high economic value and is one of the main commodities in international trade. This study aims to analyze the effect of different longline setting times on albacore tuna catches in the Seas of Benoa Harbor. The setting times compared were morning (08:00–10:00) and afternoon (14:00–16:00), focusing on the quantity and weight of the catch. The research method used was an experimental approach with two setting time treatments and nine replications for each treatment. Data obtained were analyzed using a T-test to determine significant differences between morning and afternoon catches. The results showed that the average catch in the morning was higher than in the afternoon, both in terms of individual count and fish weight. The average fish weight obtained in the morning was 63.78 kg, while in the afternoon, it was only 28.67 kg. Statistical analysis indicated a significant difference between morning and afternoon catches, with a T-Statistic value of 2.38, which exceeded the T-Critical value (2.12) at a 5% significance level (p-value = 0.0366). This suggests that the morning setting time is more optimal for catching albacore tuna than the afternoon setting. Catch variation was also greater in the morning, as indicated by a higher standard deviation compared to the afternoon. This difference may be attributed to the daily migration patterns of albacore tuna, which are more active in feeding during the morning, as well as environmental factors such as water temperature and light intensity. Based on these findings, this study recommends that fishers in the Seas of Benoa Harbor should set their longline fishing gear in the morning to maximize their catch.

One of the problems of cultivating Betta fish (Betta sp.) which can hamper this cultivation effort is the slow weight growth of the fish. The aim of this research is to determine the effect of providing different types of feed on the growth in weight and color of Betta fish (Betta sp.) size 1- 1.5 in the maintenance tank. The research containers used 27 used gallons with a capacity of 15 liters and each research container was filled with fresh water with a volume of 10 liters. The test animals used were Betta fish seeds measuring 1–1.5 cm. This research used an experimental method using an experimental design in the form of a Completely Randomized Design (CRD) with 3 treatments and 9 repetitions to obtain 27 trials. Other parameters that are also studied include water quality including water temperature ranged from 26,1 – 29 ̊C and pH (degree of acidity) ranged from 7 - 8.

The use of probiotics is very important in cultivation activities. Probiotics are live microorganisms that have a beneficial effect on the host by balancing the microflora in their intestines. In increasing the nutritional content of artificial feed (pellets), the bacteria in probiotics have a mechanism for forming several enzymes for digesting feed. This study aims to determine the effect of giving delacto probiotics at different doses in artificial feed on the absolute weight growth of tilapia (Oreochromis niloticus). Probiotics are mixed with feed using a biofloc cultivation system. The method used in this research was an experimental method with a Completely Randomized Design (CRD) with 4 treatments and 6 replications, namely by adding different doses to the treatments. Treatments A (8ml/kg), B (16 ml/kg), C (24 ml/kg) and D (32 ml/kg). The parameter observed was absolute weight growth. Water quality supporting parameters include temperature, pH and DO. Data were analyzed using the ANOVA test. Based on the research results, it shows that giving different doses of delacto probiotics has a significant effect on the absolute weight growth of tilapia (Oreochromis niloticus). Treatment A (8 ml/kg) gave the lowest absolute weight growth of 32.83 grams and treatment D (32 ml/kg) gave the highest absolute weight growth of 40.57 grams. Water quality parameters include water temperature ranging from 25.3 – 26.1֯C, acidity ranging from 7.5 – 8.0. And dissolved oxygen ranges from 4.7 – 5.3 ppm. The results of analysis of variance (ANOVA) for the three water quality parameters showed no differences between treatments (Oreochromis niloticus) fry.

Vannamei shrimp is one of the shrimp species with economic value and is one of the national leading commodities. On the other hand, one of the problems in vannamei shrimp cultivation is its slow growth, slow growth is caused by the less optimal absorption of nutrients in the feed. In dealing with these problems, one of the things that is done is the administration of probiotics. The addition of probiotics such as Biolacto containing Lactobacillus sp bacteria to the feed can increase the appetite of shrimp. This study aims to determine the effect of biolacto probiotics on feed on the growth of the absolute weight of vannamei shrimp. This study used a Complete Random Design (RAL) with four treatments: A (feed without a mixture of probiotics), B (probiotics 2 gr/100 gr feed), C (probiotics 4 gr/100 gr feed), and D (probiotics 6 gr/100 gr feed). Treatment B with a concentration of probiotics 2gr/100g feed gave the highest absolute weight growth of 9.2 gr. Water quality data during the study were obtained with water temperature ranging from 28.5 – 29.2°Celsius, salinity ranging from 36 – 37 ppt, pH ranging from 7.5 – 8.0, and dissolved oxygen ranging from 4.0 to 4.63 mg/l. The results of the ANOVA analysis of the four water quality parameters showed no difference between treatments and were in the optimal range of life of vannamei shrimp (Litopenaeus vannamei).

Giving probiotics such as probiotic boster on feed greatly helps the growth of absolute weight in Catfish seeds because the good bacteria contained in these probiotics help facilitate catfish seeds in digesting the feed so as to increase the efficiency of the feed. This study aims to see how effective the probiotic administration is. The study was conducted in Kramas District, Gianyar regency, Bali Province for 30 days using experimental methods, using a complete randomized design with a total of 4 treatments and 6 repetitions. Treatment A is by giving 3 ml of probiotic boster every 1 kg of feed. Treatment B by giving 5 ml probiotic boster every 1 kg of feed. Treatment C by giving 7 ml probiotic boster every 1 kg of feed. Treatment D by giving 9 ml probiotic boster every 1 kg of feed. In this study showed significantly different results on the addition of probiotic boster with different doses on the growth of absolute weight of catfish fry aged 1 month-2 months. Treatment D gave the highest result with an absolute weight gain of 55.33 grams, and treatment a showed the lowest result with an absolute weight gain of 25.17 grams. Water quality Data during the study obtained water temperature ranges from 27-29 oC, acidity ranges from 7-8, and dissolved oxygen ranges from 3.34 to 4.26 ppm. The results of the analysis of variance (ANOVA) of the three parameters of water quality there is no difference between the treatment and the life range of catfish fry (Clarias sp.)

The addition of probiotics such as Lactobacillus sp to fermented feed is expected to improve nutrient digestibility, suppress the growth of pathogenic microorganisms, and improve feed conversion efficiency, thereby promoting optimal shrimp growth. This study used an experimental method on vannamei shrimp doc 80 using a complete randomized design (RAL) with four treatments: P0 (feed without fermentation as a control), P1 (feed fermentation for 0 hours 10ml/100g with Lactobacillus sp), P2 (feed fermentation for 24 hours with 10ml/100g Lactobacillus sp), P3 (feed fermentation for 48 hours 10ml/100g Lactobacillus sp), P3 (feed fermentation for 72 hours 10ml/100g Lactobacillus sp) by doing 6 repetitions which were carried out for 1 month/30 days in the maintenance tub. The results showed that Treatment A without fermentation gave absolute growth with an average of 1 gr, Treatment B with no fermentation gave absolute growth with an average of 1.89 grams, Treatment C with a fermentation time of 48 hours gave absolute weight growth with an average of 2.15 grams, Treatment D with no fermentation gave absolute growth with an average of 0.74 grams. Meanwhile, the water quality parameters during the study were obtained with water temperature ranging from 28.3-29.6o C, pH ranging from 7.8-8.0, and dissolved oxygen ranging from 4.03-4.66 mg/l. With the anova test, the absolute weight growth showed that with different fermentation time differences, there was a real effect on the growth of vannamei shrimp in C treatment, which was 2.15 gr. And in the results of the anova test, the four water quality parameters were not different between the treatments and were in the optimal range in the life of vannamei shrimp. Based on this study, it can be suggested that the optimal fermented feed is in the time range of 48 hours and there is further research for doc 80 and above.

The objective of this study was to determine the effect of different percentages of natural feed (Tubifex sp.) and artificial feed on the absolute weight gain of striped catfish (Pangasius hypophthalmus) fry. The study was conducted at PBIAT Muntilan for 30 days using an experimental method. A Completely Randomized Design (CRD) was applied with five treatments and five replicates. The treatments were as follows: A (100% pellet), B (75% pellet + 25% Tubifex sp.), C (50% pellet + 50% Tubifex sp.), D (25% pellet + 75% Tubifex sp.), and E (100% Tubifex sp.). ANOVA analysis showed that different proportions of natural feed (Tubifex sp.) and artificial feed significantly affected absolute weight gain. The most optimal feeding ratio for enhancing the absolute weight gain of striped catfish fry was found in treatment E, where 100% Tubifex sp. was provided, resulting in the highest absolute weight gain of 4.876 grams. Water Quality Parameters: During the study, the recorded water temperature ranged from 25.1 to 25.4ºC, pH ranged from 6.7 to 6.8, and dissolved oxygen ranged from 6.6 to 6.7 ppm. ANOVA analysis of these three water quality parameters showed no significant differences among treatments. However, the temperature was below the optimal range for the growth of striped catfish (Pangasius hypophthalmus) fry.

Shipbuilding industrial companies still produce a number of organic waste in the form of twigs, grass and leaves. In line with developments in the current era, organic waste that accumulates will become an issue for the environment if it is not managed properly. This activity was carried out to overcome the problem of organic waste in the shipbuilding industry, by utilizing organic waste for composting. Composting is a simple anaerobic method that can be easily carried out in the shipbuilding industry. This method turns organic waste into compost by carrying out a fermentation process. Organic waste in the form of leaves that are turned into compost can increase the nutrient content in the soil. The composting process is carried out using two different activator materials, namely using Effective Microorganisms 4 (EM 4) and Promoting Microbes (PROMI). The results of the compost research carried out have met the quality standards according to SNI 19-7030-2004. The final results of these two treatments are not too different, the pH resulting from the EM4 activator treatment is 6.9 and the pH from the PROMI activator treatment is 7. The temperature value for both does not exceed the ground water temperature, namely the final temperature of the EM4 activator treatment is 29.9oC and from PROMI activator treatment of 30oC. The observation results show that of the two activators EM4 and PROMI, the one that is more effectively used for composting is the EM4 activator because the microorganism content in EM4 has more classifications compared to the PROMI activator.    

Background: Hypertension or high blood pressure is when the systolic pressure is more than 140 mmHg and the diastolic blood pressure is more than 90 mmHg. WHO data (2015) shows that around 1.13 billion people in the world have hypertension. The number of people with hypertension continues to increase every year, it is estimated that every year 20.44 million people die from hypertension and its complications. Non-pharmacological management to lower blood pressure can be done independently and naturally, namely foot hydrotherapy (warm foot bath). Foot soaks can be combined with other herbal ingredients, one of which is ginger. Objective: To determine the effect of soaking feet with warm ginger water in lowering blood pressure in hypertensive patients. Method: The application was carried out using a descriptive method in the form of a case study to 2 respondents with hypertension in the form of a pretest-posttest. The application is carried out within two days for 15 minutes by sitting on a bed or chair and then soaking the feet in a basin containing warm red ginger water with a water temperature of 37°C. Findings: Based on the results of the application of warm red ginger water foot soak therapy is decrease in blood pressure in elderly patients with hypertension, namely 160/100 mmhg and 150/100 mmhg. Implications: warm red ginger water foot soak therapy can be used as a non-pharmacological technique or independent intervention in elderly patients with hypertension

Main engine merupakan mesin utama pada kapal yang terdiri dari beberapa unit yang berfungsi untuk menggerakkan kapal. Sebelum kapal beroperasi, kondisi main engine harus dipastikan dalam keadaan baik. Untuk memastikan mesin dalam keadaan baik, perlu dilakukan perawatan dan pengujian untuk menjaga keamanan mesin. Pengujian dilakukan menggunakan system safety device yang merupakan salah satu perangkat keamanan yang digunakan untuk mencegah terjadinya kerusakan pada main engine. Pengujian safety device ini dilakukan untuk memastikan pada saat mesin beroperasi, kecepatan dan suhu dari mesin tersebut dalam kondisi sesuai standard yang sudah ditetapkan agar mesin beroperasi dalam keadaan aman. Penelitian ini bertujuan untuk mengetahui keamanan dan keselamatan diesel main engine melalui beberapa tahapan pengujian safety device dengan standard yang sudah ditetapkan oleh perusahaan mesin dan disetujui oleh Biro Klasifikasi Indonesia. Pada penelitian ini menggunakan metode pengamatan secara langsung saat proses pengujian. Adapun hasil dari penelitian ini menunjukkan pengujian safety device melalui tahapan mulai dari pengujian fresh water temperature, pengujian oil pressure, pengujian oil leaking, pengujian over speed. Dari keempat pengujian tersebut maka didapatkan hasil yang optimal dan aman dalam mengoperasikan mesin induk kapal Tug Boat karena memenuhi persyaratan sistem safety device dari standar maker serta di approve oleh Biro Klasifikasi Indonesia.

Water is very important for all aspects of life on earth, agriculture is one of the fields that really need large amounts of water because of the use of water in the process of plant photosynthesis. Water that has good quality is if the water is not excessively polluted by harmful chemicals or minerals. One indicator that water is polluted is a change in temperature and pH (acidity) of the water. Temperatures that are too hot in the water will interfere with the growth of plants and other microorganisms. While the normal pH of water has a pH that ranges from 6.5 to 7.5. The quality of water and soil is very important in agriculture. The level of acidity (pH) and soil temperature are one of the things that affect plant fertility. Therefore, the quality of water and soil on agricultural land is one of the important things that needs special attention in its management. One solution so that water and soil quality can be monitored and managed efficiently is to utilize a Wireless Sensor Network based on the Internet of Things (IoT). The use of the ESP8266 Module as a WIFI module, is widely used by Internet of Things-based applications because the price is cheap so it reduces a lot of costs and has a fairly good speed of 80 MHz. This study aims to develop the concept of a Wireless Sensor Network by utilizing the ESP8266 module to monitor pH values using a pH Meter Analog Kit sensor and temperature from agricultural land using a DS18B20 Waterproof sensor and can be monitored at any time using a smartphone.

Hydroponics are now increasingly in demand, should be checked regularly so that hydroponic plants thrive. Likewise, in Siliwangi Indah Hydroponics Semarang, which still uses manual methods, namely the absence of a device that detects nutrient water temperature and pH automatically and the absence of tools that can normalize nutrients automatically. Arduino Uno R3 can be used to detect temperature automatically with a temperature sensor DS18B20, and detect pH with a pH sensor. Then the sensor readings are sent to the farmer's cellphone with SMS Gateway. The sensor readings are also used to divert the flow of nutrients from the spare reservoir, so that the nutrients remain normal. So this tool can automatically measure the nutrient water temperature and pH and replace the main nutrients to the reserve nutrients. And the assessment obtained from experts on this tool gets a value of 3.6 and from the expert gets a value of 3.7. Hydroponic nutrition in this study is maintained normally and farmers always know the nutritional state. So that the hydroponic plants thrive and have maximum yields.