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KAJI EKSPERIMENTAL PENGARUH BAFFLE PADA ALAT PENUKAR PANAS ALIRAN SEARAH DALAM UPAYA OPTIMASI SISTEM PENGERING Azwinur Azwinur; Zulkifli Zulkifli
SINTEK JURNAL: Jurnal Ilmiah Teknik Mesin Vol 13, No 1 (2019): SINTEK JURNAL
Publisher : University of Muhammadiyah Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24853/sintek.13.1.8-14

Abstract

Heat exchangers or heat exchangers are tools used to change the temperature of the fluid or change the fluid phase by exchanging heat with another fluid. In a heat exchanger, the ability to exchange heat is largely determined by the type of fluid flow and fluid passing through the heat exchanger. The use of heat exchangers in the field of drying is now a necessity to overcome the problems of drying productivity. The purpose of this study was carried out to determine the effectiveness of the heat exchanger experimentally based on directional flow by comparing construction using baffle and without using baffle in an effort to optimize the drying system. The research method was carried out by fabricating 2 units of heat exchangers and by field testing. The test data obtained are the input and output temperatures of the heating fluid flow and cooling fluid flow and flow velocity. Based on preliminary research data shows that the use of baffle affects the increase in temperature on the heat exchanger, where at the fresh air outlet that does not use baffle produces a temperature of 72oC while the baffle produces 88oC with the Log Mean Temperature Difference heat exchanger without using a baffle higher than heat exchanger that uses a baffle guide blade. This can illustrate that the smaller heat losses are wasted so that the absorption of heat by the reverse system will be higher.
Isolasi Senyawa Anti Bakteri Geraniol Dari Minyak Sereh Wangi (Citronella Oil) Dengan Menggunakan Distilasi Vakum Uswatun Hasanah; Zulkifli Zulkifli; Teuku Rihayat; Andi Wardana; Cut Nazia N
Jurnal Teknologi Vol 21, No 1 (2021): April 2021
Publisher : Politeknik Negeri Lhokseumawe

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (303.824 KB) | DOI: 10.30811/teknologi.v21i1.2208

Abstract

This study aims to increase geraniol levels in citronella oil, using vacuum distillation. Geraniol is a compound that has been legalized by IFRA (Fragrance International Association) as a scent compound, so geraniol is a reference to be formulated in the form of Anti-bacterial perfume products, but the levels of geraniol in citronella oil are still very low. This encourages the processing of fragrant citronella oil to be processed, by increasing geraniol levels using vacuum distillation, with variations in pressure: 8,6,4,2,1 mbar, during operating times: 20, 40, and 60 minutes up to FBP ( Final Boiling Point). Samples were analyzed using GC-MS (Gas Chromatography-Mass Spectrometry), FT-IR, refractive index, and bacterial testing. The results showed that the use of low pressure affected increasing geraniol levels. The maximum increase in geraniol content was 80.11% at a pressure of 1 mbar at the Final Boiling Point operation, with a refractive index of 1.501, whereas in the FTIR test there was an intense broad peak in the range 2200-3200 cm-1 especially at 3086.98cm-1 according to the OH hydroxyl polymer group at Geraniol. This study increased geraniol levels from 20.32% to 80.11%.
Pembuatan Pestisida Nabati dari Daun (Balakacida, Serai dan Sirsak) dengan Perbandingan Penambahan Surfaktan dan Tanpa Surfaktan Dinda Amalia; Sariadi Sariadi; Zulkifli Zulkifli
Jurnal Teknologi Vol 23, No 2 (2023): Oktober 2023
Publisher : Politeknik Negeri Lhokseumawe

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30811/teknologi.v23i2.4471

Abstract

Production of vegetable pesticides from leaves (lemongrass, balakacida, and soursop) with a ratio of surfactant addition and no surfactant is carried out by liquid-solid extraction. This research aims to influence the effect of the use of leaf types and the use of surfactants and without surfactants with differences in maceration time on the quality of the vegetable pesticides produced. The research method was carried out by maceration extraction which would release flavonoid compounds and a mortality test was carried out on black ants (Dolichoderus thoracicus). The research results obtained from the three raw materials, namely balakacida leaves with the addition of surfactant, were the best results which desired to achieve a lethal dose (LD 100) with all test ants dead, whereas, without the addition of surfactant, it only reached the middle lethal dose (LD 50). As the maceration time increases, the number of ant deaths increases. The characteristics of vegetable pesticides produced from flavonoid levels have a positive correlative relationship to the mortality of black ants (Dolichoderus thoracicus). So what was obtained in the test for flavonoid compounds produced an orange/yellow color and there were functional groups OH, C-H, N-O, N=C=S, and C=C.
Kaji eksperimental perbedaan perpindahan panas peleburan parafin sebagai material penyimpan panas pada alat penukar kalor pipa mulus dan pipa bersirip Zulkifli Zulkifli
Jurnal POLIMESIN Vol 15, No 1 (2017): Februari
Publisher : Politeknik Negeri Lhokseumawe

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30811/jpl.v15i1.371

Abstract

Dalam penelitian ini, kajian eksperimental berkaitan dengan perpindahan panas laten dan penyimpanan energi termal menggunakan tabung pipa mulus. Sebuah unit  eksperimental terdiri dari akuisisi data, heat exchanger jenis shell and tube digunakan untuk meningkatkan perpindahan panas, pipa fluida panas dirancang mulus (tanpa sirip). Lilin parafin digunakan sebagai media penyimpanan termal. Karakteristik perpindahan panas dari fluida ke lilin parafin diselidiki dalam kondisi fluks panas yang berbeda. Hasil percobaan menunjukkan bahwa karakteristik transfer panas menunjukkan kesamaan untuk tabung penukar panas. Pada proses pemanasan awal didominasi oleh konduksi, tetapi pada suhu leleh didominasi oleh perpindahan panas konveksi.Kata kunci: Parafin, perpindahan panas, penyimpanan panas, pipa mulus, pipa bersirip
Analisa kekuatan impak pada penyambungan pengelasan smaw material ASSAB 705 dengan variasi arus pengelasan Saifuddin A.Jalil; Zulkifli Zulkifli; Tri Rahayu
Jurnal POLIMESIN Vol 15, No 2 (2017): Agustus
Publisher : Politeknik Negeri Lhokseumawe

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30811/jpl.v15i2.376

Abstract

Penelitian ini bertujuan untuk mengetahui pengaruh arus pengelasan pada kekuatan dan ketangguhan las SMAW dengan elektroda E7018.Penelitian ini menggunakan bahan baja ASSAB 705, baja ini termasuk baja karbon rendah. Bahan di beri perlakuan pengelasan dengan variasi arus100 Ampere, 125 Ampere, dan 150 Ampere dengan menggunakan las SMAW DC polaritas terbalik dengan elektroda di hubungkan dengan kutub positif dan logam induk di hubungkan dengan kutub negatif, posisi pengelasan dengan menggunakan posisi pengelasan mendatar atau bawah tangan, jenis kampuh yang di gunakan adalah kampuh V dengan sudut 70°.  Spesimen di lakukan pengujian Impak metote Charpy. Hasil pengujian impak pada kelompok specimen base metal dan specimen variasi arus menunjukkan bahwa nilai kekuatan impak yang paling tinggi terdapat pada base metal yaitu sebesar 146 joule dan 1,825 joule/mm2, dibanding dengan kelompok variasi arus 100 Ampere, 125 Ampere dan 150 Ampere. Jenis-jenis perpatahan yang terjadi adalah pada base metal dan kelompok spesimen arus 100 Ampere adalah patah getas, dan kelompok spesimen 125 Ampere dan kelompok spesimen 150 Ampere adalah patah ulet. Kata kunci : Arus, SMAW, ASSAB 705, ketangguhan, E7018