PENGARUH KECEPATAN DAN SIFAT FLUIDA PENDINGIN TERHADAP KOEFISIEN PERPINDAHAN KALOR PADA PENUKAR KALOR SHELL AND TUBE

Penelitian ini dilakukan untuk melihat pengaruh perubahan kecepatan fluida pendingin dan pengaruh sifatfisik fluida pendingin terhadap koefisien perpindahan kalor pada penukar kalor shell and tube. Penelitian dilakukandengan menggunakan tiga macam fluida pendingin, yaitu dengan fluida pendingin air, fluida pendingin air yangditambahan coolant produksi SPC dan fluida pendingin air yang ditambahkan coolant produksi Tiga Berlian.,Penambahan coolant pada air pendingin untuk masing-masing coolant dilakukan dengan dua tahapan, yaitudengan campuran (67 % air + 33 % coolant) dan (50 % air + 50 % coolant). Pada setiap campuran dilakukandengan enam variasi kecepatanAir panas dialirkan melalui tube pada temperatur  60 oC dengan laju aliran 0,1245 kg/s, sedangkanfluida pendingin dialirkan melalui shell (di luar tube) pada temperatur  42 oC dengan 6 variasi laju aliran, yaitu: 0,1012 kg/s; 0,1115 kg/s; 0,1285 kg/s; 0,1390 kg/s; 0,1495 kg/s dan 0,1590 kg/s.Dari hasil penelitian terlihat bahwa alat penukar kalor shell and tube dengan fluida pendingin campuranair dengan coolant pada kondisi yang dipilih mempunyai bilangan Nusselt yang lebih tinggi dari padamenggunakan media pendingin air tanpa campuran coolant. Dan dengan penambahan laju aliran fluida pendinginlaju perpindahan kalor yang terjadi akan meningkat sehingga koefisien perpindahan kalor keseluruhan juga akanmeningkat.Kata Kunci : fluida pendingin, penukar kalor, shell and tub

ANALISIS PERILAKU PERPINDAHAN KONSUMEN TERHADAP PEMAKAIAN AIR MINERAL DALAM KEMASAN DENGAN MENGGUNAKAN MARKOV CHAIN (Studi Kasus : Kecamatan Manyar dan Kecamatan Gresik)

Dewasa ini banyak sekali produk instan yang beredar dipasaran dengan menawarkan berbagai macam keunggulan dan manfaatnya masing-masing. Salah satu produk yang bermain dipasar sekaligus memiliki pasar yang sangat potensial adalah air mineral. Dengan adanya persaingan antar perusahaan air minum dalam kemasan akan membuat konsumen benar-benar selektif dalam mengambil keputusan pembelian. Secara jelas masyarakat cenderung bersikap rasional dan selektif terhadap pembelian barang yang diinginkannya baik kualitas produk maupun harganya. Disisi lain dengan tumbuhnya pesaing-pesaiang baru maka perusahaan dituntut untuk mengambil langkah dan menerapkan strategi yang tepat untuk mempertahankan pelangganny

PERENCANAAN DESAIN ALAT BANTU TEMPORARY CLAMP 8” PADA PIPE LINE INDUSTRI MIGAS

Abstrak: Salah satu bentuk kerusakan pada pipa adalah rusaknya struktur material pipa yang menyebabkan kebocoran akibat kegiatan pihak ketiga / Third Party Damaged. Kegagalan pipa yang menyebabkan kebocoran apabila tidak dengan segera ditanggulangi dapat berakibat pada kerugian Perusahaan hingga pencabutan izin usaha. Berdasarkan rujukan dari Pipeline Research Council International (PRCI) terdapat beberapa metode perbaikan permanen pada pipa yang diakibatkan oleh kebocoran antara lain menggunakan Sleeve Type B, Bolt-On Clamp with Seal dan Hot Tapping (PRCI : Pipeline Repair Manual, 2006). Metode Perbaikan tersebut memiliki beberapa kelebihan dan kelemahan masing-masing dengan tingkat kerumitan pengerjaan dan biaya investasi yang beraneka ragam. Bolt-On Clamp with Seal banyak dipilih di Industri Migas Indonesia sebagai metode perbaikan yang praktis. Beberapa product Bolt-On Clamp telah banyak diperjual belikan dipasaran dengan harga yang mahal dan waktu pengiriman yang sangat lama serta memerlukan beberapa persiapan tekniss ebelum proses pemasangannya seperti pembersihan sisa minyak dipermukaan pipa, pengupasan coatin pipa, surface preparation dan lain-lain.Tidak dilakukannya persiapan teknis yang sesuai standar pabrikan dapat menyebabkan tidak maksimalnya kekuatan Bolt On Clamp sesuai dengan tujuan perbaikanya untuk mengembalikan integritas pipa. Mengingat pentingnya menjaga integritas pipa dan meminimalisir kerugian perusahaan sehingga diperlukan improvement terkait metode-metode perbaikan sementara / termporary repair yang efektif sebelum dilakukan permanent repair. Maka dari pada itu perlu adanya rancang bangun suatu model temporary clamp 8” yang dapat mengatasi kebocoran pipe line efektif dan efisien,dengan melalui serangkaian pembuatan desain temporary clamp 8”, perhitungan rancang bangun alat dan pengujian temporay clamp 8”. Kata kunci: penjepit, proses terminologi piping, pipeline, sistem transportasi pipelin

Experimental and simulation Studies of a Two Seater Light Aircraft

This paper presents the aerodynamic studies carried out on a three-dimensional aircraft model. The test model is a 15% scaled down from a two-seater light aircraft that close to the Malaysian made SME MD3-160 aircraft. The aircraft model is equipped with control surfaces such as flaps, aileron, rudder and elevator and it is designed for pressure measurement testing and direct force measurement using a 6-components balance system. This aircraft model has been tested at two different low speed tunnels, at Universiti Teknologi Malaysia tunnel sized 1.5 x 2.0 meter2 test section, and at Institute Aerodynamic Research, National Research Council of Canada sized 3 x 2 meter2 tunnel. The speed during testing at UTM and IAR/NRC tunnels was up to 70 meter/second, which is corresponds to Reynolds numbers of 1.3 x 106.The longitudinal and lateral directional aerodynamic characteristics of the aircraft such as coefficients of pressure, forces (lift, drag, side) and moments (roll, pitch and yaw) have been experimentally measured either using direct force measurement or pressure measurement method. The data reduction methods include the strut support interference factor using dummy image and the blockage correction have been applied in this project. The results showed that for the undeployed flap configuration, the stalling angle of this aircraft is 160 at CLMax = 1.05 measured by UTM - LST, compared to CLMax =1.09 at stalling angle 150 by IAR- NRC. Beside the experimental study, simulation also be performed by using a commercial Computational Fluid Dynamics (CFD) code, FLUENT Version 5.3. Experimental works at UTM and IAR – NRC tunnel show that the aerodynamic characteristics of this light aircraft are in a good agreement with each other. Simultaneously, the aerodynamic forces obtained from experimental works and CFD simulations have been compared. The results proved that they are agreeable especially at a low angle of attack

Penerapan Model Quantum Teaching Untuk Meningkatkan Hasil Belajar IPS Siswa Kelas V SD Negeri 147 Pekanbaru

This research was conducted because of the result of learning science study class V SD Negeri 147 Pekanbaru. KKM achieved by school was 75. From 32 students who achieve KKM just 14 students (43.75%) while students who did\u27nt achieve KKM is 18 students (56.25%) with a class average of 72.15. The purpose of this research to improve outcomes IPS class V SD Negeri 147 Pekanbaru with the application of learning models Quantum Teaching. The results obtained by the average value of 72.15 basic score increased in the first cycle of 3,30% to 74.53. In the second cycle the average value of students also increased by 10,66% to 79.84. On the basic of classical completeness score IPS student learning outcomes is only 43,75% (not finished). After the professor of applied model Quantum Teaching in the first cycle classical completeness increased to 56,25% (not finished), and the second cycle of classical completeness obtained are increased to increase to 78,12%. Activities of teachers at the first meeting of first cycle acquire a percentage of 70% with good categories. The second meeting increased to 79% in good categories. In the first meeting of second cycle increased to 84% with very good category. At the second meeting increased to 90% with very good category. Activities of students in the first meeting of the first cycle acquire a percentage of 68% with good categories. The second meeting increased to 77% in good categories. In the first meeting of the second cycle increased to 81% with very good category. At the second meeting increased to 86% with very good category

Trainee teachers' perception towards using first language to facilitate the teaching of an ESL classroom / Muhammad Faiz Mat Lazim

This study intends to explore and investigate the perceptions of the trainee teachers' towards using first language to facilitate the teaching of an ESL classroom. This study aimed to discover the trainee teachers 'perception towards using first language to facilitate the teaching of English classes, the most popular approach in using first language to teach ESL classroom and also the limitations of using first language to facilitate the teaching of second language. 70 sets of questionnaires were distributed among the respective Semester 8 TESL students in UiTM Shah Alam Section 17 and all of it were returned back and were analyzed and also summarized. The results of the findings show that most of the trainee teachers' agreed that first language can be used to facilitate the teaching of an ESL classroom but with the proper method and some appropriate boundaries. It is because overuse of first language could bring negative effects to the students as well as to the teachers

Relationship between entrepreneurial orientation, firm resources, SME branding and firm’s performance: is innovation the missing link?

Innovation is regarded as an engine for driving economic growth.Innovation is considered equally important for the large enterprises as well as the Small and Medium Enterprises (SMEs).Role of innovation becomes of even greater importance in the context of the business environment of developing countries such as Pakistan, where most of the SMEs do not embrace rigorous innovation and at the same time there is lack of sufficient external support to encourage innovation.It has been discussed that despite of healthy economic contribution to Pakistan’s Economy, SMEs are facing a low growth trap.Innovation can come up as a potential solution specifically for Pakistani SMEs and generally for SMEs in developing countries in other parts of the world. This paper reviews the literature in a thorough manner in a bid to build a novel conceptual framework proposing that innovation has causal linkages with entrepreneurial orientation, firm resources, branding and firm performance. On the basis of literature review, four thoughtful research propositions have been presented in this paper. The proposed framework can lead to very useful insights as it proposes that branding may lead to innovation as opposed to generally believed concept of innovation leading to branding. This paper is built on the underpinning theories like Resource Based View, Dynamic Capabilities Perspective, and Theory of Economic Development. This paper also provides useful implications for the entrepreneurs as well as external institutions responsible for ensuring higher extent of innovation in SMEs in Pakistan

Bipolar complex fuzzy credibility aggregation operators and their application in decision making problem

A bipolar complex fuzzy credibility set (BCFCS) is a new approach in computational intelligence and decision-making under uncertainty. Bipolar complex fuzzy credibility (BCFC) information has been employed as a strategy for dealing with confusing and unreliable situations that arise in everyday life. In this paper, we used the concept of aggregation operators to diagnose the well-known averaging and geometric aggregation operators, as well as evaluate some properties and related results. Using described operators, an algorithm for multiple criteria group decision making is proposed. Then, a numerical example of a case study of Hospital selection is discussed. Lastly, the comparative analysis of suggested operators with existing operators are also given to discuss the rationality, efficiency and applicability of these operators

Sine hyperbolic fractional orthotriple linear Diophantine fuzzy aggregation operator and its application in decision making

The idea of sine hyperbolic fractional orthotriple linear Diophantine fuzzy sets (sinh-FOLDFSs), which allows more uncertainty than fractional orthotriple fuzzy sets (FOFSs) is noteworthy. The regularity and symmetry of the origin are maintained by the widely recognized sine hyperbolic function, which satisfies the experts' expectations for the properties of the multi-time process. Compared to fractional orthotriple linear Diophantine fuzzy sets, sine hyperbolic fractional orthotriple linear Diophantine fuzzy sets (sinh-FOLDFSs) provide a significant idea for enabling more uncertainty. The objective of this research is to provide some reliable sine hyperbolic operational laws for FOLDFSs in order to sustain these properties and the significance of sinh-FOLDFSs. Both the accuracy and score functions for the sinh-FOLDFSs are defined. We define a group of averaging and geometric aggregation operators on the basis of algebraic t-norm and t-conorm operations. The basic characteristics of the defined operators are studied. Using the specified aggregation operators, a group decision-making method for solving real-life decision-making problem is proposed. To verify the validity of the proposed method, we compare our method with other existing methods