ANALISA NILAI KEKASARAN PERMUKAAN MAGNESIUM YANG DIFREIS DALAM KONDISI TERSUPLAI UDARA DINGIN

The use of magnesium material, as alternative to iron and steel, is becoming more popular. Besides the fact that it is lighter, magnesium is popular because it is available in a quite large quantity in this world. To make magnesium to be a machine component, there is a process needed to be done, which is known as machining process. The machining process done in several conditions doe to the pharamater or factor in machining process.. The examples of cutting pharameter are feed rate, cutting speed, and deep of cutting. This research used magnesium as the material of research. The purpose of this research is to investigate the influence of cutting pharameter to the surface roughness of magnesium machined with milling process ang supplied with cooling air from vortex tube cooler. Cutting pharameter used in this research are feed rate and cutting speed. Feed rate used was three levels, those are 0,15 mm/rev, 0,20 mm/rev, and 0,25 mm/rev. Cutting speed used also three levels, those are 23,18 m/min, 32,15 m/min and 42,7 m/min. Cooling air is released from vortex tube cooler with 15 oC of temperature. The result of this research is found that feed rate affect the number of magnesium surface roughness very significan. It can makes the number of surface roughness higher. Another pharameter, cutting speed also affect the number of magnesium surface roughness. It can make the number of surface roughness decreased. The number of magnesium surface roughness is also affected by nose radius, vibration, and cutting force.Keywords: magnesium material, surface roughness, milling, cutting pharameter, cooling air

IMPLEMENTASI MODEL EDUPRENEUSHIP SEBAGAI UPAYA INTERNALISASI KARAKTER WIRAUSAHA GURU SMK BANDAR LAMPUNG

Abstrak: Sekolah Menengah Kejuruan (SMK) memiliki peran besar dalam mempersiapkan calon tenaga kerja terampil yang siap agar siap memasuki dunia kerja. Oleh karena itu, SMK harus bertransformasi menjadi lembaga pendidikan unggul yang didukung oleh kurikulum, guru, dan praktik manajemen sekolah yang baik. Terbatasnya sumber pendanaan lembaga pendidikan menyebabkan proses transformasi ini menjadi terhambat. Oleh karena itu, salah satu upaya mengatasi hambatan ini adalah dengan mengimplementasikan Edupreneuship. Tujuan kegiatan ini adalah untuk mengenalkan Edupreneuship pada guru SMK Bani Plus Salim Bandar Lampung.Untuk mengenalkan Edupreneuship pada guru SMK Plus Bani Salim maka metode yang digunakan adalah dengan memberdayakan para guru melalui kegiatan workshop, pelatihan, dan pendampingan. Target kegiatan adalah terimplementasinya Edupreneuship pada SMK Plus Bani Salim Bandar Lampung. Luaran kegiatan adalah terjadinya peningkatan pengetahuan guru SKM Plus Bani Salim dalam mengimplementasikan Edupreneuship. Luaran wajib lainnya adalah sebuah artikel jurnal nasional, publikasi di media massa, dan video kegiatan.Hasil kegiatan workshop mampu meningkatkan pengetahuan guru SMK Plus Bani Salim sebesar rata-rata 40,44%. Capaian ini telah melampaui hasil yang ditargetkan dimana rata-rata nilai post test peserta adalah 80,30. Target kegiatan untuk menghasilkan unit u saha baru bagi sekolah masih dalam proses persiapan dan belum bisa direalisasikan pada tahun 2021 karena terkendala dana. Abstract: Vocational High School is an educational institution that is needed to equip prospective professional workers with practical skills so that they are ready to compete in the labor market. Excellent educational institutions require school management, teachers, and curriculum are good. Unfortunately, not many Vocational School are able to meet these criteria due to the lack of institutional funding sources. Therefore, schools need to implement Edupreneuship. The purpose of this community service activity is to improve the knowledge and skills of teachers in implementing Edupreneuship.The method used is empowering teachers and school management. The empowerment activity is carried out in the form of workshops, training, and mentoring. The target of this activity is the implementation of Edupreneuship at SMK Plus Bani Salim. The output of this activity is an increase in knowledge of teacher and school management in implementing Edupreneuship. Other outputs are a national journal article, publication in mass media, and activity videos.The workshop activities carried out succeeded in increasing participants' knowledge with an average increase of 40.44%. The achievement of the indicators for the success of the workshop has exceeded the target where all participants have a post test score of 75 or more. The target to produce new business units for schools has not been achieved because it is still in the preparation process and cannot be realized this year due to funding constraints

Geometry Optimization of PV/T-TEG Collector under Different Operating Conditions Using CFD Simulation and Taguchi Method

PV panel connected within both fins and TEG that is well known as a PV/T-TEG system. The system increases the electrical efficiency affected by the thermal collector and contributes to additional electricity due to the temperature difference of the TEG sides. However, optimizing the thermal performance of the system involved the geometry parameters and operating conditions, it still requires many combinations of factors and levels. In the present study, Taguchi Method with five factors, three levels, and two responses is then implemented to reduce the number of combinations which are related to fin geometry, air mass flow rate and solar irradiation under different operating conditions. Air as a working fluid is applied with the inlet fluid temperature based on the tropical climate in Indonesia. The two responses are needed to be lower in temperature of the PV panel and higher in temperature difference of TEG sides respectively. Furthermore, Computational Fluid Dynamics (CFD) method is applied as an approach to generate the responses numerically. The results revealed that the combinations of the geometric parameters and operating conditions for achieving the optimal PV temperature are found to be the full fin arrangement, fin height of 75 mm, fin thickness of 3 mm, and air mass flow of 0.08 kg/s and heat absorbed of 400 W/m2. Thus, the combinations to obtain the optimal TEG temperature difference are staggered fin arrangement, fin height of 25 mm, fin thickness of 1 mm, the mass flow of 0.08 kg/s and heat absorbed of 800 W/m2. Additionally, the heat absorbed factor has the biggest impact on PV temperature change with the contribution of 47.57% of the total five factors. Meanwhile, fin arrangement is the factor that has the biggest impact on the temperature difference of TEG sides with a contribution of 33.31%

PENGARUH PUTARAN DAN KECEPATAN TOOL TERHADAP SIFAT MEKANIK PADA PENGELASAN FRICTION STIR WELDING ALUMINIUM 5052

Aluminium is a metal that has a good resistance against corrosion, this is because the occurrence of the phenomenon of pasivasi. In addition to its resistance to corrosion, aluminium also has a lighter weight compared to steel, so aluminium is frequently used as one of the materials used in the manufacture of ships, especially on the upper deck of the building, insulation, fuel tanks and  freshwater tank.Welding is the process of connecting between two or more metal parts by using thermal energy.In general aluminum welding using fusion welding processes such as Metal Inert Gas and Metal Inert Gas, but on both of these methods there is possibility formation of defects are porosity, cracks and prone to occurringdeformationduringcooling processof dan the formation ofmetalwelding. The purpose of this study was to determine the effect of tool rotation and welding speed on the mechanical aspect of Aluminium 5052 with the friction stir welding method.The parameters of the   welding process is done on the research this is is the round tool and welding spee is is the round tool and welding speed.Round tool used there are two namely 1800 rpm and 1100 rpm. The speed of welding is also used there are two variations,namely 11.4 mm/min and 19.8 mm/min. As for the mechanical tests conducted there are three, namely testing the hardness, impact test, and tensile testing.The result of this research was the discovery that the round tool and welding speed greatly affect the mechanical properties of aluminium that has been welded. Because the tool is rotating faster increases the tensile strength of aluminium, while the small welding speed will increase the hardness of aluminum that has been welded. Keywords : aluminium, welding, friction stir welding, mechanical aspect of metal

Analysis of Surface Roughness Value When Drilling Magnesiumaz31 Using Taghuci Method

Magnesium alloy is one of super alloys material which wide used in manufacturing of automotive, biomedic, sport and electronic components. It was due to very light and resistent to corrosion. Surface roughness value has an important role to estabilish the quality of components. To produce a good surface roughness of machined surface, one of the important thing depends on the friction between the cutting tool and workpiece material when cutting process occurred. The aim of this paper is to analyse the surface roughness values of machined surface when drilling of magnesium alloy AZ31 using design of experiment of Taguchi Method. The experimental trials took place at cutting rotation of 635, 970 and 1420 rpm, feed rate of 0.10, 0.18 and 0.24 mm/rev, diameter tool of 10, 12 and 14 mm. The cutting of magnesium alloy was done by using a convensional drilling machine with TCA –35Erlo. Analysis of variance on the data of surface roughness value was done to get which factor is the most significant. The result shows that the feed rate is the most significant factor that contributed on the surface rougness value of machined surface. The minimum surface roughness value was attained at cutting rotation of 970 rpm, feed rate of 0.10 mm/rev and diameter of tool of 14 mm. Therefore, it can be stated that selecting the low feed rate factor produced low surface roughness value. Another hand, using high cutting rotation resulted low surface roughness value.Keywords—drilling, surface roughness, magnesiun AZ31,Taguchi Metho

PENGARUH UKURAN BUTIR SERBUK FLY ASH TERHADAP KEKUATAN IMPACT BAHAN KOMPOSIT BERMATRIKS EPOXY

Mixing types of epoxy polymers with fly ash (fly ash) coal into composite materials is expected to be one of the ways to look for an alternative to metal materials. Mixing two different materials is intended to improve the mechanical properties of composites by utilizing waste coal as a reinforcing material. Making specimens was based on differences in particle size of the fly ash powder. Fly ash sifted with a sieve to obtain a variation of the size of the fly ash particles with a size of 40 mesh, 80 mesh and 120 mesh. While the epoxy resin used was a general purpose type (Bisphenol Aepichlorohydrin) Bakelite EPR 174 with a ratio between the epoxy resin and hardener 1:1. After getting the fly ash according to the desired size, made by mixing epoxy resin through the calculation of the mass fraction. The process of mixing epoxy resin with coal fly ash waste is done with matrix mixing ratio by 60% and 40% fly ash. Then do the impact test for pure epoxy resin and for composites. Fracture area photo by scanning electron microscope (SEM) was used to analyze the causes of failure in composites. Testing was conducted ann accordance with the standard impact test ASTM D 6110. The test results showed the addition of fly ash particles with increasing particle size of 40 mesh, 80 mesh and 120 mesh can improve the impact strength of the composite. Highest impact strength of the composite obtained at 120 mesh particle size of 3.967 x 10-3 J/mm2. With the decrease in the size of particles, extensive contact between the surface of fly ash with resin will be many more. So, to the improve impact strength. In the SEM image results look excellent interface bonding between the matrix with fly ash particles. In the composite looks much voids or porosity.Keywords: epoxy, composites, fly ash, impact test, SEM photos, the mechanical properties

Pembuatan Mesin Cetak Pelet Pakan Ternak Berbahan Baku Onggok Untuk Kelompok Peternak Sapi di Terbanggi Subing Lampung Tengah

Desa Terbanggi Subing merupakan salah satu desa yang di Kecamatan Gunung Sugih, yang mana sebagian besar penduduknya bertani dan berternak sapi dengan beberapa kelompok peternak.  Sementara itu UMKM produksi pakan ternak dan kelompok peternak yang bergerak dibidang penggemukan sapi. Tujuan kegiatan ini adalah membuat mesin pencetak pelet pakan sapi menggunakan bahan baku onggok sehingga memudahkan peternak dalam menjalan usaha ternak sapi dengan pola dikandangkan. Pembuatan mesin cetak pelet menggunakan metode ekstruder menggunakan poros berulir dengan kecepatan tertentu. Pencampuran dilakukan sebelum masuk ke ekstruder. Kemudian poros berulir digerakan menggunakan mesin diesel 10 PK guna menghasilkan daya torsi yang besar.  Daya motor direduksi menggunakan sistem gearbox sehingga mendapatkan kecepatan putaran lebih rendah dengan torsi yang lebih besar. Mesin yang dibuat memiliki kapasitas produk hingga mencapai 100 kg/jam. Dengan demikian produksi mesin cetak pelet mampu memproduksi hingga 800 kg setiap harinya

Optimasi nilai keausan pahat dan kekasaran permukaan benda kerja terhadap parameter pemesinan milling dengan benda kerja magnesium menggunakan kombinasi metode taguchi dan grey relational analysis

The Taguchi method is widely used to determine the optimal quality of a process with a single response. While for multi-response cases, Grey Relational Analysis (GRA) and Principal Component Analysis (PCA) are widely used. With multi-phone GRA, it can be simplified into one single response. Tool wear and surface roughness of the workpiece in the milling machining process is affected by the diameter of the tool, depth of feed, spindle speed, and feeding speed. This study examines the response of tool wear and work surface roughness with three levels and four factors. For tool diameters, using 6.8 mm and 10 mm. The depth of feed used 1; 1,5 mm and 2 mm. Spindle speeds at 910, 1280, and 1700 rpm. While the feeding speed is 75 mm/minute, 145 mm/minute, and 220 mm/minute. Optimal results obtained in conditions of 6 mm tool diameter with 1,5 mm depth of feeding, spindle speed of 1280 rpm, and feeding speed of 75 mm/minute. The optimal response obtained is 0,059 mm for tool wear and 0,364 μm for work surface roughness. The significant factor influencing is the feeding speed which influences 76,14 %.Keywords: Grey Relational Analysis, Principal Component Analysis, Taguchi Method, Milling, Tool Wear, Roughnes