PELATIHAN TARIAN KATAGA DI SANGGAAR PEKAA DAPAT MENINGKATKAN KEBUGARAN AEROBIK DAN KEKUATAN OTOT PADA REMAJA SUMBA DI BALI

Kebugaran fisik adalah kemampuan tubuh untuk melakukan tugas dan pekerjaan sehari-hari dengan giat, tanpa mengalami kelelahan yang berarti serta dengan cadangan energi. Unsur-unsur ini  berkaitan dengan proses latihan yang dilakukan oleh olahragawan atau penari sehingga bisa mempersiapkan kondisi fisik agar selalu prima. Pelatihan tari Kataga merupakan latihan dengan beban berat tubuh dengan cara menjaga keseimbangan serta meningkatkan daya tahan tubuh yang kuat. Bentuk latihan lain adalah pelatihan aerobik, merupakan aktivitas olahraga secara sistematis dengan peningkatan beban secara bertahap dan terus menerus yang menggunakan energi hasil pembakaran dengan menggunakan oksigen. Penelitian ini bertujuan untuk meningkatkan kebugaran fisik remaja Sumba di Sanggar Pekaa Bali. Jenis penelitian menggunakan with control group desain. Subjek penelitian remaja Sumba di Sanggar Pekaa Bali berjumlah 20 orang dan dibagi dalam dua Kelompok perlakuan yang berbeda. Kelompok I diberikan pelatihan tari Kataga dan Kelompok II diberikan latihan aerobik dengan frekuensi latihan 3 kali seminggu selama 6 minggu. Berdasarkan uji statistik parametrik paired-sample t test dengan p-value 0,00 < 0,05. Squat - kekuatan tungkai bawah, Sit Up - kekuatan otot core, Pull Up - kekuatan otot lengan, Lari 1,4 m - kebugaran aerobik. Berdasarkan uji statistik diperoleh peningkatan kemampuan aerobik dan kekuatan otot yang bermakna sebelum dan setelah perlakuan pada kedua kelompok. Jumlah repetisi Squat, Sit Up, Pull Up sebelum latihan pada kelompok 1 sebesar 19,6, 15,9, 15,5, dan setelah latihan sebesar 25,9, 23,2, 19,4 Pada kelompok 2 diperoleh hasil 14,9, 16,7, 17.8, dan setelah latihan sebesar 20,3, 23,6, 21,7.  Untuk kebugaran aerobik diperoleh hasil waktu tempuh lari 1,4 km pada kelompok 1 sebelum perlakuan sebesar 7,83 menit, dan setelah perlakuan sebesar 19,34 menit Pada Kelompok 2 diperoleh hasil 9,73 dan 23,26. Uji statistik antar kelompok menunjukkan bahwa hasil latihan pada kelompok 1 memiliki data bermakna dari kelompok 2. Simpulan Kelompok I dan Kelompok II sama-sama memberi efek peningkatan yang bermakna (p<0,05) dan kelompok I (Kataga) lebih meningkatkan kebugaran fisik dari pada Kelompok II (Latihan Aerobik). Saran untuk penelitian ini diharapkan para penari dapat menjaga kebugaran fisiknya agar tetap seha

Visualization and Simulation of Oil Flow in a Scroll Compressor Plenum

Discharge valves located in the compressor plenum are the gateway for the lubrication oil to leave the compressor to the system. The space of compressor plenum has the potential to separate oil droplets which can decrease the oil circulation ratio. In this paper, video processing method is used to capture the oil droplets distribution near the discharge valve and in the discharge tube in a running system. Discrete phase model in computational fluid dynamics is used as the numerical approach to study the oil flow inside compressor plenum. To validate the CFD simulation, size distribution from video processing at the valve is used as the input of the calculation and the calculation results are compared to size distribution in the discharge tube. Calculation shows how oil droplets are size distribution affect the oil flow in the plenum.

The Performance of an Automotive Carbon Dioxide Heat Pump System in Frosting and Defrosting

This paper presents the performance in frosting and defrosting of an automotive carbon dioxide (CO2) heat pump system, which is composed of a microchannel indoor and outdoor coil, a reciprocating compressor, an electronic expansion valve, and an integrated accumulator and internal heat exchanger. The effects of the criterion for the start of defrosting on the heat pump system performance were investigated experimentally. The defrost-start criterion was determined based on the reduction in the performance of the heat pump system instead of only considering the performance of the outdoor coil. Results show the heat pump system can operate for 64 minutes at 0℃ and 90% RH with a defrost-start criterion of 10 times the initial air-side pressure drop. The accumulator and internal heat exchanger improve system efficiency during frosting conditions. The mass of frost accumulation increases faster in the first 40 minutes and slower in the next 24 minutes for 0℃ and 90% RH. The retained water on the outdoor coil gets saturated after three short frosting/ defrosting cycles or a 64-minute long run. Also, the frosting and defrosting processes are monitored by a web camera to investigate the frost distribution on the two-pass outdoor microchannel heat exchanger. The results are presented for evaluating the frosting distribution and the effects on the overall performance of the heat pump system

Heat Transfer of Condensation in Smooth Round Tube from Superheated Vapor

Heat transfer of R134a condensing in a horizontal smooth round tube with 6.1 mm inner diameter is invested in this study. Experimental results on the heat transfer coefficient (HTC) with mass flux from 50 to 200 kg m-2 s-1 and heat flux from 5 to 15 kW m-2 are provided. Heat transfer behavior is compared between condensing superheated (CSH) region and two-phase (TP) region. Experimental result shows that in TP region, higher mass flux results in higher HTC while heat flux does not affect HTC. In CSH region, however, mass flux does not affect HTC while HTC increases when heat flux increases. Based on the flow characterization, the heat transfer behavior in CSH region is contrary to that suggested by liquid film geometry, where higher mass flux means thinner film whose HTC is higher and heat flux does not alter HTC a lot. In addition, the consistent peak of HTC at quality one cannot be physically explained while the reason for the counterintuitive heat transfer behavior actually lies in the conventional definition of HTC. Therefore, a new definition of heat transfer coefficient, described as “film heat transfer coefficient†is proposed to better represent the physics and serve as a preparation for the new heat transfer model

Design of Capacitive Sensors for Measuring Void Fraction in Headers of Microchannel Heat Exchangers

This paper presents the design and building of capacitive sensors for measuring void fraction in headers of microchannel heat exchangers with R134a. The capacitive sensors utilize different electrical properties (dielectric constant) between the liquid and vapor phases to measure the void fraction of two-phase flow. The test section (a header) is made of 3D printed partitions with a total length of 185.8 mm and an inner diameter of 15.8 mm (D). It has eleven microchannel-tube protrusions with a depth of half inner diameter. All microchannel tubes are capable of being connected to real aluminum tube-like real heat exchangers in the future study. Eleven capacitive sensors locate between protrusions. Each sensor has two concave-plate electrodes with the axial length of the half inner diameter (D/2). With these eleven sensors, void fractions along the header can be measured spontaneously. Preliminary validation of the sensors is also presented in this paper

Experimental and Numerical Study of a Mobile Reversible Air Conditioning-Heat Pump System

Electric vehicles suffer from range anxiety, while traditional resistive heating consumes a lot of electric energy and reduces EV drive range largely. Mobile reversible air conditioning-heat pump system is an energy efficient way of providing heat to EV cabin climate. In this paper, an AC/HP system was built based on the Nissan Leaf system configuration and experimentally studied. This system consists of three heat exchangers, an open-shaft compressor, two expansion valves, and two flow control valves. Heating performance of the system under various operating conditions was extensively investigated. Controlling subcooling was found a beneficial way of obtaining higher energy efficiency. Refrigerant charge imbalance when switching modes was found to be a challenge, and was studied both experimentally and numerically. Careful positioning of expansion valves, and sizing of liquid lines in both modes are essential in avoiding large charge imbalance. Component wise, the outdoor heat exchanger holds much more charge in AC mode than in HP mode. A steady state simulation model of the components and the system was developed and reasonably validated against experimental data. Options for improvement of the system based on modeling prediction were provided and discussed