scholarly journals PERUBAHAN SUHU LINGKUNGAN TERHADAP WAKTU TRIP PADA MINI CIRCUIT BREAKER 6A TIPE C

2020 ◽  
Vol 5 (1) ◽  
pp. 6-13
Author(s):  
Dhelvian Gading Primadhika ◽  
Parjiman ◽  
Djaohar Mochammad ◽  
Himma Firdaus
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Ambient Temperature ◽  
Temperature Effect ◽  
Temperature Change ◽  
Research Result ◽  
Circuit Breaker ◽  
Reference Temperature ◽  
Voltage Source ◽  
Circuit Breakers

ABSTRACT The purpose of this research is to know about the effect of current rate increasing and ambient temperature change on tripping time miniature circuit breakers 6A type C. In this research using an experimental method approach with the quantitative method. The research subject used five samples new miniature circuit breakers produced by Asian and European brand. The research data collection is carried out by testing using PLN voltage source, linier load and temperature change on chamber to know five samples miniature circuit breakers characteristics tripping time refer to SPLN 108:1993. The research result showed that, current rate increasing to ± 2.55 In and ambient temperature change have an effect on five samples miniature circuit breakers characteristics tripping time, where on reference temperature, different characteristics tripping time for each other however were still within the standard limits SPLN 108:1993. Next on low temperature testing, five samples miniature circuit breakers have change tripping time to be slowed rather than reference temperature testing with deviation MCB A 1.75 until 497.90 second, MCB B 3.81 until 114.89 second, MCB C 2.04 second until 637.42 second, MCB D 0.33 until 1647.96 second, dan MCB E 2.89 until 234.49 second. Last on high temperature testing five samples miniature circuit breakers have change tripping time to be faster rather than reference temperature testing with deviation MCB A 2.63 until 396.93 second, MCB B 2.78 until 251.96 second, MCB C 5.79 second until 775.25 second, MCB D 8.27 until 339.49 second, dan MCB E 3.86 until 95.02 second. Based on this research result, each increase current rate flow through miniature circuit breakers, than miniature circuit breakers tripping time to be faster. When miniature circuit breakers was given low temperature effect, than miniature circuit breakers have change tripping time to be slowed rather than reference temperature. While miniature circuit breakers was given high temperature effect, than miniature circuit breakers have change tripping time to be faster rather than reference temperature.   ABSTRAK Tujuan dari penelitian ini adalah untuk mengetahui pengaruh kenaikan besar arus listrik yang disertai dengan perubahan suhu lingkungan terhadap waktu trip pada mini circuit breaker 6A Tipe C. Metode yang digunakan adalah metode eksperimen dengan pendekatan metode kuantitatif. Subjek penelitian yang akan diteliti adalah MCB yang dalam kondisi baru berjumlah 5 sampel produksi asia maupun eropa. Pengumpulan data penelitian dilakukan dengan pengujian menggunakan sumber tegangan PLN, beban linier dan perubahan suhu di chamber pengujian untuk mengetahui karakteristik waktu trip 5 MCB yang mengacu pada SPLN 108:1993. Hasil penelitian menunjukan bahwa, peningkatan besar arus hingga ±2.55 In dan perubahan suhu mempunyai pengaruh terhadap karakteristik waktu trip 5 sampel MCB, dimana pada suhu refrensi masing-masing memiliki perbedaan karakteristik waktu trip namun masih dalam batas standar SPLN 108:1993. Lalu pada pengujian dengan suhu rendah, 5 sampel MCB masing-masing mengalami perubahan waktu trip yang lebih lambat dari pengujian pada suhu refrensi dengan deviasi MCB A 1.75 hingga 497.90 detik, MCB B 3.81 hingga 114.89 detik, MCB C 2.04 detik hingga 637.42 detik, MCB D 0.33 hingga 1647.96 detik, dan MCB E 2.89 hingga 234.49 detik. Sedangkan pada pengujian dengan suhu tinggi 5 sampel MCB masing-masing mengalami perubahan waktu trip yang lebih cepat dari pengujian pada suhu refrensi dengan deviasi MCB A 2.63 hingga 396.93 detik, MCB B 2.78 hingga 251.96 detik, MCB C 5.79 detik hingga 775.25 detik, MCB D 8.27 hingga 339.49 detik, dan MCB E 3.86 hingga 95.02 detik. Dari hasil pengujian yang telah dilakukan di dapatkan hasil semakin besar arus yang melewati MCB maka akan lebih cepat MCB akan trip. Lalu dengan di beri pengaruh suhu rendah, maka MCB akan lebih lambat untuk trip. Sedangkan dengan di beri pengaruh suhu tinggi, maka MCB akan lebih cepat untuk trip.

Temperature Effect of Refining Performance by Al-Ti-B (C) Master Alloys

2011 ◽  
Vol 306-307 ◽  
pp. 475-480
Author(s):  
Cong Juan Gao ◽  
Hai Min Ding ◽  
Xiang Fa Liu
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Temperature Effect ◽  
Master Alloy ◽  
Experimental Results ◽  
Refining Effect ◽  
Master Alloys ◽  
Refining Performance ◽  
Tib2 Particles ◽  
Performance And Mechanism

Refining performance and mechanism of Al-5Ti-1B and Al-5Ti-0.4C master alloys at different temperature were investigated in this paper. The experimental results show that the refining effect of Al-5Ti-0.4C master alloy becomes worse as temperature increasing from 750°C to 1200°C, The refining effect of Al-5Ti-1B master alloy becomes worse as temperature increasing from 750°C to 1000°C. However, when the temperature is above 1000°C, the refining effect of Al-5Ti-1B master alloy recovers gradually as temperature increasing. TiB2 particles with TiAl3 layers are the heterogeneous nucleating cores of α-Al at low temperature. However, TiB2 particles are the heterogeneous nuclei of α-Al at high temperature.

scholarly journals A revised method to predict skin’s thermal resistance

2018 ◽  
Vol 22 (4) ◽  
pp. 1795-1802
Author(s):  
Lijuan Wang ◽  
Ding Chong ◽  
Yuhui Di ◽  
Hui Yi
Keyword(s):  
Heat Flux ◽  
High Temperature ◽  
Low Temperature ◽  
Thermal Resistance ◽  
Ambient Temperature ◽  
Skin Temperature ◽  
Heat Loss ◽  
Human Body ◽  
New Formula ◽  
Sweat Evaporation

Human body can adjust heat loss by vasoconstriction, vasodilatation, and other methods. The purpose of this research is to investigate whether the thermal resistance of skin reflects vasoconstriction and vasodilatation. For this aim, the ambient temperature was controlled as 18.1, 21.6, 24.9, 27, and 30.5?C, respectively. In each temperature, the skin temperature and heat flux in the forearm were recorded. Based on tested data, the thermal resistance was calculated by a common method. The results showed that the thermal resistance at low temperature was less than that at high temperature, which was contrary to the rule of vasoconstriction and vasodilatation. So a new formula for thermal resistance was presented based on skin diffusion, sweat evaporation, and mass transformation. The results showed that the new method could predict vasoconstriction and vasodilatation. The revised equation is a useful index for physiological thermoregulation.

scholarly journals A Hybrid DC Circuit Breaker with Fault-Current-Limiting Capability for VSC-HVDC Transmission System

Energies ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2388 ◽  
Author(s):  
Muhammad Ahmad ◽  
Zhixin Wang
Keyword(s):  
Energy Absorption ◽  
Direct Current ◽  
Circuit Breaker ◽  
Good Alternative ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Fault Current ◽  
Circuit Breakers ◽  
Current Limiting ◽  
Hybrid Circuit

The direct current circuit breakers are considered a promising option to protect the transmission line against commonly appearing line-to-ground fault. However, the challenges of losses in the nonoperational stage, escalation of response against fault current, and large fault current handling capability remain the debatable issues for direct current circuit breakers. This paper introduces a novel topology of the hybrid circuit breaker with fault-current-limiting characteristics, which contains three branches: the main branch, fault-current-limiting branch, and energy absorption branch. The main branch includes a mechanical switch, breaker impedance, and bidirectional power electronics switches. In the fault-current-limiting branch, a fault-current-limiting circuit is introduced which contains n numbers of bidirectional switches and current-limiting inductors, which are connected in series to make the design modular in nature. During the normal working stage, the current flows through the main branch of the breaker. Once a fault in the system is confirmed, the fault current is transferred to the fault-current-limiting branch. At this stage, the intensity of the fault current is reduced significantly using the fault-current-limiting circuit, and finally, the residual current is shifted to the energy absorption branch. The working principle, design considerations, and parametric analysis concerning the design of hybrid circuit breakers are incorporated in this paper. The performance of the proposed breaker is evaluated using a three-terminal voltage-source converter-based high-voltage direct current transmission network; for this purpose, a PSCAD/EMTDC simulation tool is used. The performance of the proposed breaker is also compared with other topologies. The comparative analysis shows that the proposed breaker is a good alternative considering high fault current interruption requirements, response time against fault current, and power losses.

The Ratio of Sunflower Pollens Foraged by Apis mellifera Is More Than That of Apis cerana Does During Sunflower Blooming

Sociobiology ◽  
2020 ◽  
Vol 67 (2) ◽  
pp. 256
Author(s):  
Huipeng Yang ◽  
Jia Sun ◽  
Peng Tang ◽  
Changsheng Ma ◽  
Shudong Luo ◽  
...  
Keyword(s):  
High Temperature ◽  
Apis Mellifera ◽  
Low Temperature ◽  
Ambient Temperature ◽  
Honey Bee ◽  
Apis Cerana ◽  
Pollen Foraging

Bias foraging of pollen is general in different pollinators since various nutrition demanding, co-evolution and interaction of insect-plant. To clarify the preference of pollen foraging during sunflower blooming, the pollen foraging behaviors of Apis mellifera Linnaeus and Apis cerana Fabricius were observed. Our results displayed that two summits of pollen foraging occurred in the morning before the ambient temperature climbed up to thirty-one degree centigrade and in the afternoon after the ambient temperature decreased below thirty-one degree centigrade, respectively. Notably, the first foraging summit of Apis cerana emerged one hour earlier than that of Apis mellifera. These results imply that Apis mellifera is less resistant to low temperature but more resistant to high temperature than Apis cerana does. The colonies were surrounded by sunflowers with sporadic weeds, while only few maize dispersed over two hundred meters away. However, no more than forty percent of total pollens foraged by Apis mellifera was from sunflower, and which was no more than twenty percent in Apis cerana group. These results suggest that sunflower pollens are not the prior choice for both honey bee species, while the ratio of sunflower pollens foraged by Apis mellifera is more than that of Apis cerana does.

Ambient Temperature Operation of a Platinum-Free Direct Formate Fuel Cell

2015 ◽  
Vol 12 (1) ◽  
Author(s):  
Tien Q. Nguyen ◽  
Daniel Minami ◽  
Chau Hua ◽  
Austin Miller ◽  
Kevin Tran ◽  
...  
Keyword(s):  
High Temperature ◽  
Fuel Cell ◽  
Low Temperature ◽  
Ambient Temperature ◽  
Power Density ◽  
Second Generation ◽  
Cathode Catalyst ◽  
Maximum Power Density ◽  
Direct Formate Fuel Cell ◽  
Fuel Stream

Several reports have been made recently of the direct formate fuel cell (DFFC) operating at high-temperature and using Pt cathode catalyst. In the present work, we demonstrate a Pt-free DFFC employing ACTA HypermecTM 4020 Fe–Co second-generation cathode catalyst operating at low-temperature. We report a maximum power density (PD) of 45 mW cm−2 at ambient temperature (20 °C), when the fuel stream was 1 M HCOOK and 2 M KOH with oxygen used at the cathode. When air was used at the cathode, the maximum PD was 35 mW cm−2. When hydroxide was removed from the fuel stream and oxygen used at the cathode, the maximum PD at 20 °C was 18 mW cm−2. This low-temperature, KOH-free operation is important to development of a practical DFFC.

Cycling ambient temperature effect on boar semen

1984 ◽  
Vol 38 (1) ◽  
pp. 129-132 ◽  
Author(s):  
H. Heitman ◽  
J. R. Cockrell ◽  
S. R. Morrison
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Ambient Temperature ◽  
Temperature Stress ◽  
Semen Quality ◽  
High Temperature Stress ◽  
Low Temperature Stress ◽  
Temperature Cycle ◽  
Control Group ◽  
Medium Temperature

ABSTRACTTwenty-four 1-year-old boars of proven fertility were assigned randomly to one of two temperature-controlled trailers. A control group in each trial was held at 17 ± 0·5°C while the other group was exposed to a diurnal ambient temperature cycle. Cycles followed a sine-wave pattern with minimum and maximum temperatures occurring at 04.00 and 16.00 h respectively. Cycling temperature ranges were 17 to 33 ± 0·5°C (low-temperature stress), 19·5 to 35·5 ± 0·5°C (medium-temperature stress), and 22 to 38 ± 0·5°C (high-temperature stress). Semen samples were collected every 3 or 4 days over an experimental period of 42 days.Low-temperature stress and medium-temperature stress boars were not affected significantly in the five parameters of semen quality observed. The difference between controls and high-temperature stress boars was highly significant for motility, abnormal spermatozoa, gel-free volume, and total spermatozoa per ejaculate. Concentration of spermatozoa was not affected by treatment. Significant time effects were observed for motility, abnormal spermatozoa and total spermotozoa per ejaculate. Significant differences began to appear after 2 or 3 weeks and changes still appeared to be occurring at 6 weeks.

scholarly journals The Mortality Risk and Socioeconomic Vulnerability Associated with High and Low Temperature in Hong Kong

2020 ◽  
Vol 17 (19) ◽  
pp. 7326
Author(s):  
Sida Liu ◽  
Emily Yang Ying Chan ◽  
William Bernard Goggins ◽  
Zhe Huang
Keyword(s):  
Socioeconomic Status ◽  
Hong Kong ◽  
High Temperature ◽  
Low Temperature ◽  
Temperature Effect ◽  
Mortality Risk ◽  
Extreme Temperature ◽  
Subtropical Climate ◽  
Socioeconomic Vulnerability ◽  
Death Registry

(1) Background: The adverse health effect associated with extreme temperature has been extensively reported in the current literature. Some also found that temperature effect may vary among the population with different socioeconomic status (SES), but found inconsistent results. Previous studies on the socioeconomic vulnerability of temperature effect were mainly achieved by multi-city or country analysis, but the large heterogeneity between cities may introduce additional bias to the estimation. The linkage between death registry and census in Hong Kong allows us to perform a city-wide analysis in which the study population shares virtually the same cultural, lifestyle and policy environment. This study aims to examine and compare the high and low temperature on morality in Hong Kong, a city with a subtropical climate and address a key research question of whether the extreme high and low temperature disproportionally affects population with lower SES. (2) Methods: Poisson-generalized additive models and distributed-lagged nonlinear models were used to examine the association between daily mortality and daily mean temperature between 2007–2015 with other meteorological and confounding factors controlled. Death registry was linked with small area census and area-level median household income was used as the proxy for socioeconomic status. (3) Results: 362,957 deaths during the study period were included in the analysis. The minimum mortality temperature was found to be 28.9 °C (82nd percentile). With a subtropical climate, the low temperature has a stronger effect than the high temperature on non-accidental, cardiovascular, respiratory and cancer deaths in Hong Kong. The hot effect was more pronounced in the first few days, while cold effect tended to last up to three weeks. Significant heat effect was only observed in the lower SES groups, whilst the extreme low temperature was associated with significantly higher mortality risk across all SES groups. The older population were susceptible to extreme temperature, especially for cold. (4) Conclusions: This study raised the concern of cold-related health impact in the subtropical region. Compared with high temperature, low temperature may be considered a universal hazard to the entire population in Hong Kong rather than only disproportionally affecting people with lower SES. Future public health policy should reconsider the strategy at both individual and community levels to reduce temperature-related mortality.

scholarly journals PENGARUH DISTORSI HARMONISA TERHADAP KINERJA TRIP MINIATURE CIRCUIT BREAKER TIPE C 2A, 4A, DAN 6A DENGAN SUMBER TEGANGAN PLN DAN GENSET

2020 ◽  
Vol 4 (1) ◽  
pp. 28-34
Author(s):  
Unfa Solfiani ◽  
Purwanto Gendroyono ◽  
Imam Arif Raharjo
Keyword(s):  
Power Quality ◽  
Circuit Breaker ◽  
Harmonic Distortion ◽  
Voltage Source ◽  
Harmonic Load ◽  
Research Subjects ◽  
Circuit Breakers ◽  
Quality Analyzer ◽  
Non Linear ◽  
Non Linear Load

The purpose of this study was to determine the effect of harmonic distortion with harmonic load on the performance of trip Type C Flow Miniature circuit breakers 2A, 4A, and 6A The method used is descriptive quantitative method. The research subjects to be examined are miniature circuit breakers. In collecting data, carried out harmonic load population testing and testing with a Power Quality Analyzer with a voltage source PLN and Genset, the results of MCB samples obtained were analyzed for trip characteristics referring to SPLN 108 : 1993 and IEEE. The results showed that from testing trip characteristics using harmonic loads and PLN voltage sources and generators carried out on miniature circuit breakers trip changes occurred which were still within the standard limits of SPLN 108: 1993. Then the results of testing of non-linear load such as a combination of incandescent, spotlight lamps, and fluorescent lamp ballast electronic, with currents flowing at 1.5 x In on the MCB. In the MCB using the PLN voltage source get MCB 2A THD Current 71.45%, MCB 4A THD Current 46.64%, MCB 6A THD Current 34.71% while the MCB using Genset voltage source get MCB 2A THD Current 52.07%, MCB 4A THD Current 31.54%, MCB 6A THD Current 24.62%. From the tests that have been done in getting the results, the greater harmonic distortion (THD Current) can affect the working mechanism of the MCB which results in faster MCB termination time in terminating the circuit. ABSTRAK Tujuan dari penelitian ini adalah untuk mengetahui pengaruh distorsi harmonisa dengan beban harmonik terhadap kinerja trip miniature circuit breaker Tipe C Arus 2A, 4A, dan 6A   Metode yang digunakan adalah metode deskriptif kuantitatif. Subjek penelitian yang akan diteliti adalah miniature circuit breaker Pada pengumpulan data, dilakukan pengambilan populasi beban harmonik dan melakukan pengujian dengan alat ukur Power Quality Analyzer dengan sumber tegangan PLN dan Genset, hasil pengujian sampel MCB yang didapat lalu dianalisis mengenai karakteristik trip yang mengacu pada SPLN 108:1993  dan IEEE Hasil penelitian menunjukkan bahwa dari pengujian karakteristik trip dengan menggunakan beban harmonik dan sumber tegangan PLN dan genset yang dilakukan pada miniature circuit breaker terjadi perubahan trip yang masih dalam batas standar SPLN 108:1993. Kemudian hasil pengujian terhadap beban non linear berupa lampu hemat energi, lampu spotlight, dan kombinasi lampu pijar dengan arus yang di alirkan sebesar 1.5 x In pada MCB. Pada MCB dengan menggunakan sumber tegangan PLN di dapatkan MCB 2A THD Arus 71.45%, MCB 4A THD Arus 46.64%, MCB 6A THD Arus 34.71% sedangkan Pada MCB dengan menggunakan sumber tegangan Genset di dapatkan MCB 2A THD Arus 52.07%, MCB 4A THD Arus 33.35%, MCB 6A THD Arus 24.62%. Dari pengujian yang telah dilakukan di dapatkan hasil semakin besar distorsi harmonik arus (THD Arus) maka dapat mempengaruhi mekanisme kerja pada MCB yang mengakibatkan waktu pemutusan MCB menjadi lebih cepat dalam melakukan pemutusan rangkaian.

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