<p>Indonesia adalah salah satu negara tropis sehingga banyak sumber energi yang dapat dimanfaatkan untuk keperluan pertanian, termasuk sebagai sumber energi alat pengering hasil panen. Dengan demikian, di berbagai negara tropis, banyak dijumpai alat-alat pengering produk pertanian dengan memanfaatkan berbagai sumber energi, salah satunya adalah pengering dengan energi surya sebagai sumber panas. Namun, alat-alat seperti ini sulit untuk digunakan oleh para petani yang berdomisili di beberapa tipe lokasi, seperti lereng pegunungan yang cukup terjal. Sinar matahari yang optimal sulit diperoleh karena tertutup oleh pepohonan dan tebing. Oleh karena itu, makalah ini bertujuan untuk menyampaikan hasil rancangan alat pengering berbahan bakar kayu bakar dengan desain yang efektif dan efisien. Alat pengering ini adalah jenis tak kontak langsung, tipe tray bertingkat yang berputar serta mempunyai kelebihan dari sisi kepraktisan dan meminimalkan energi panas yang terbuang. Produk pertanian yang dikeringkan ditaruh secara merata di atas tray-tray lima tingkat, selanjutnya udara panas mengalir dari bawah memanasi produk pertanian mulai dari tingkat satu sampai dengan tingkat lima. Produk pertanian tersebut dapat direlokasi dengan cara memutar tuas masing-masing tray secara berurutan, sehingga produk pertanian jatuh dengan sendirinya ke tingkat tray dibawahnya. Dengan cara demikian, harapannya produk pertanian memperoleh kalor pengeringan yang sama atau hampir sama dan merata. Alat pengering telah diujicoba untuk mengeringkan biji kakao yang difermentasi dan hasil pengeringannya baik dengan pengurangan kadar air sampai hampir 50%.</p>

Canard configuration on fighter planes is essential for regulating flow and the occurrence of vortex interactions on the main wing, one of which is to delay stall. Stall delays are useful when the aircraft is making maneuvering or short-landing. This study observed the effect of canard configuration on various fighter aircraft models. Fighter models represented the different canard configurations, such as Sukhoi SU-30 MKI, Chengdu J-10, and Eurofighter Typhoon. Water tunnels and computational fluid dynamics (CFD) have made it easier to visualize the flow and aerodynamic forces. The results showed that at a low angle of attack (AoA) < 30°, the Chengdu J-10 and Eurofighter models had the highest lift force coefficient (Cl). When at high AoA, Cl’s highest value occurred on the Sukhoi SU-30 model with a value of 1.45 at AoA 50°. Meanwhile, the highest AoA that still had a high Cl value occurred on the Sukhoi SU-30 and Chengdu J-10 aircraft models, namely at AoA 55° with Cl values more than 1.1. The canard position in the upper of the wing would increase the Cl at low AoA, while the parallel canard position could delay the stall.

Bi-directional turbines that are commonly applied to convert wave energy into motion energy are the types of Impulse turbines and Wells turbines. Both types of turbines each have advantages and disadvantages. In this research, hybrid turbine type is designed and made to bridge the weaknesses in impulse turbine and turbine wells. Hybrid turbines are made by placing impulse turbines on the outside while turbine wells placed on the inside. In this research, the variation of hybrid bi-directional turbine design aims to find out the most optimal design of this turbine type. Six variations were carried out including a hub to tip ratio of 0.5 with 4 and 5 Wells blades, a hub to tip ratio of 0.6 with 4 and 5 Wells blades, and a hub to tip ratio of 0.7 with 4 and 5 Wells blades. From the test results on thermoacoustic engine media, based on the hub to tip ratio, the most optimal hub to tip ratio is in the order of 0.7 then 0.6, and 0.5. Whereas based on the number of Wells blade, obtained the number of Wells blade 5 is more optimal than the number of Wells blade 4.

The food industry has taken advantage of additive manufacturing technology to create food from complex ingredients customized as needed. Research on 3d printing of food, especially chocolate, has been carried out, but it needs further development related to nutritional ingredients and the accuracy of printing results. This research was conducted to design an extruder nozzle from a 3D printer used to print chocolate. The extruder nozzle was manufactured using a stainless-steel tube with a diameter of 30 mm with a heater on the outside. The heating control method used a digital thermostat STC-1000, which controls the minimum and maximum operating temperature. The digital thermostat is connected to the heater and fan, which work alternately to get a chocolate temperature distribution that matches the printing specifications. The results showed that the control temperature in the extruder was between 32.2-32.3 °C and could produce an average chocolate printing temperature of 33.4 °C. This configuration produces a stable and continuous extrusion of chocolate on the chocolate 3d printer machine.