Cooling on electronic objects, especially laptop is something to note. If the cooling system is not good, there will be overheating on the main chip motherboard and other components so that the laptop will be damaged quickly. This research aims to determine the temperature distribution on the heat sink laptop so that overheat can be overcome. This research was carried out numerically, where the specimen was a heat sink component on a laptop unit simulated using Solid works 2011 software in three dimensions with variations carried out in the form of air velocity values passing through the specimens of 5, 10, and 15 m/s. The results obtained in this study showed that the higher the speed of air flow through the heat sink, the higher the transfer of heat transfer.

The availability of electrical energy in Indonesia is a very important factor in encouraging development. Increased development, especially in the industrial sector in the form of factories and home industries, continues to grow rapidly. These developments include economic and population growth, so that the need for electrical energy continues to increase. The Pelton turbine is an electrical energy generator that utilizes water as a propeller or bucket on the rotating wheel of the Pelton turbine. So that, it is expected as an alternative to provide electrical energy needs, especially in the industrial sector. This study aims to determine the effect of variations in the angle of the nozzle spray on the triangular blade on the performance of the Pelton turbine. The variations of the nozzle spray angle include 30º, 45º, and 90º. Each nozzle spray angle is varied to the valve opening angle of 60º, 75º, 90º with lamp loads of 0, 5, 10, 15, 20, 25 Watt. Based on the results of this study, it is proven that the nozzle spray angle of 90º has the best results at a valve opening angle of 90º and a lamp load of 15 Watt which produces a generator power of 6.784 Watt with an efficiency of 54.04%. Keywords— Pelton turbine with triangular blade, nozzle spray angle, valve opening angle, generator power, efficiency.

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ABSTRAKDesa Mentaras Kecamatan Dukun Kabupaten Gresik merupakan salah satu sentral pertanian dan peternakan di kabupaten Gresik. Salah satu mata pencaharian yang ditekuni penduduk adalah beternak sapi dan kambing. Pakan memegang peranan yang sangat penting dalam rantai produksi  peternakan. Masalah yang dialami peternak desa mentaras yakni proses penyajian pakan kepada ternak biasanya dilakukan secara langsung, tanpa perlakuan atau manipulasi sebelumnya. Hal ini dapat mengurangi efisiensi dalam penggunaan pakan hijauan. Penyajian pakan tersebut cenderung menghasilkan sisa  makanan karena tidak habis dimakan maupun jatuh ke tanah. Kegiatan ini bertujuan untuk memberikan solusi pengolahan pakan ternak untuk mengatasi permasalahan yang dihadapi masyarakat Desa Mentaras. Metode pengabdian masyarakat ini adalah membuat mesin cacah rumput yang digunakan untuk mencacah rumput pakan ternak baik rumput basah maupun rumput kering. Setelah mesin tersebut selesai, kemudian dilakukan workshop penggunaan mesin untuk mencapai tujuan yang telah direncanakan. Hasil dari pengabdian ini diwujudkanlah mesin sesuai dengan konsep desain. Mesin ini menggunakan motor listrik berdaya 1 Hp dan mempunyai kecepatan putar motor 1420 RPM. Kapasitas produksi mesin ini yakni 100 kg/jam untuk pencacahan rumput basah dan 70 Kg/jam untuk pencacahan rumput kering. Dengan adanya mesin ini maka rumput ternak telah tercacah dengan ukuran 3-4 cm dan dapat ditambahkan bahan lainnya guna menambah gizi ternak, sehingga lebih sehat dan gemuk. Kata kunci: mesin cacah; pakan ternak; ternak. ABSTRACTMentaras Village, Dukun District, Gresik Regency is one of the centers of agriculture and animal husbandry in Gresik Regency. One of the livelihoods occupied by residents is raising cows and goats. Feed plays a very important role in the livestock production chain. The problem experienced by farmers in Mentaras village is that the process of serving feed to livestock is usually done directly, without any previous treatment or manipulation. This can reduce efficiency in the use of forage feeds. The presentation of the feed tends to produce food residue because it is not eaten or falls to the ground. This activity aims to provide solutions for animal feed processing to overcome the problems faced by the Mentaras Village community. This community service method is to make a grass chopper machine that is used to chop animal feed grass, both wet grass and dry grass. After the machine is finished, then a workshop on the use of the machine is carried out to achieve the planned goals. The result of this service is that the machine is realized according to the design concept. This machine uses an electric motor with a power of 1 HP and has a motor rotation speed of 1420 RPM. The production capacity of this machine is 100 kg/hour for chopping wet grass and 70 kg/hour for chopping dry grass. With this machine, the livestock grass has been chopped with a size of 3-4 cm and other ingredients can be added to increase the nutrition of the livestock, making it healthier and fatter. keywords: chopping machine; animal feed; livestock

Vibration is one of the problems that must be reduced in a vehicle. There are many ways to reduce vibration in vehicles, one of them is by adding Dynamic vibration absorber (DVA). While Dual Dynamic vibration absorber (dDVA) is a DVA period that is able to move in the translational direction given to the system to reduce translation vibration and when there is resonance. Translation DVA is an additional type of time used to reduce the vibration of the translation direction. So far there is not much research related to the use of translational DVA to reduce rotational vibrations as well as translation. In this study, a study was conducted related to the use of independent double translational DVA (dDVA) to reduce translation vibrations as well as rotation of the beam. The research was conducted by modeling the system obtained into mathematical equations and simulations were carried out to determine the characteristics of vibrations that arise. In the simulation, one of the DVA periods is placed at the center of the main system period, while the other DVA period is given a change between the center period and the end of the system. The results of the study show that the maximum reduction in translational vibration is 95.51% and occurs when the absorber is placed at the center of the system, while the maximum rotation vibration reduction is 56.62% and is obtained when the system is given with an arm ratio of 1 and zero.