scholarly journals Analisa Korelasi Nilai Konduktivitas Air Pendingin Terhadap Efisiensi Turbin Uap PLTP Karaha

Jurnal METTEK ◽  
2021 ◽  
Vol 7 (1) ◽  
pp. 19
Author(s):  
Ernanda Ginting ◽  
Aryantono Mortowidjojo ◽  
Priyono Atmadi
Keyword(s):  
Mass Balance ◽  
Pearson Correlation ◽  
Cooling Water ◽  
Scatter Plot ◽  
Water Conductivity ◽  
Two Phase ◽  
Iron Mineral ◽  
Average Value ◽  
Turbine Efficiency ◽  
Phase Production

Uap yang digunakan sebagai penggerak turbin berasal dari sumur produksi dua fasa dengan karakteristik water dominated. Selain water dominated, uap dari sumur mengandung banyak mineral dari perut bumi seperti Silika, Klorida, Sodium, Kalsium, Sulfate, Potasium, Magnesium, Boron dan Iron. Mineral tersebut ikut terlarut bersama uap yang terkondensasi menjadi kondensat, kondensat yang didinginkan untuk dipakai kembali sebagai air pendingin mengandung zat-zat pengotor yang mempengaruhi proses heat mass balance PLTP Karaha 1x30MW.Kondisi tersebut merupakan masalah yang diangkat pada penelitian ini dengan melakukan uji analisa korelasi konduktivitas air pendingin terhadap efisiensi PLTP Karaha 1x30MW dengan menggunakan software orange 3.27.1.Dari hasil analisa pearson correlation, scatter plot dan distributions didapatkan korelasi yang cukup kuat antara konduktivitas air terhadap efisiensi turbin dengan nilai koefisien pearson correlation yang sebesar -0.436. Konduktivitas air pendingin dengan nilai rata-rata 1181 µS/cm memiliki efisiensi turbin diatas 71.5%, sedangkan konduktivitas air pendingin dengan nilai rata-rata 1248 µS/cm memiliki efisiensi turbin dibawah 66.4%. Sehingga dapat disimpulkan kenaikan dan penurunan konduktivitas air pendingin memiliki korelasi dengan efisiensi turbin uap PLTP Karaha 1x30 MW. The steam used to drive the turbine comes from a two-phase production well with the characteristic of being water dominated. Apart from water dominated, steam from the wells contains many minerals from the bowels of the earth, such as Silica, Chloride, Sodium, Calcium, Sulfate, Potassium, Magnesium, Boron and Iron. These minerals are also dissolved with the steam which condenses into condensate, condensate which is cooled to be reused as cooling water contains impurities that affect the heat mass balance process of PLTP Karaha 1x30MW.This condition is a problem that is raised in this research by analyzing the correlation analysis of cooling water conductivity to the efficiency of Karaha 1x30MW PLTP using orange 3.27.1 software.From the analysis of the pearson correlation, scatter plot and distributions, it was found that there was a strong correlation between water conductivity and turbine efficiency with the pearson correlation coefficient value of -0.436. The conductivity of the cooling water with an average value of 1181 µS / cm has a turbine efficiency above 71.5%, while the conductivity of the cooling water with an average value of 1248 µS / cm has a turbine efficiency below 66.4%. So it can be concluded that the increase and decrease in cooling water conductivity has a correlation with the efficiency of the Karaha 1x30 MW PLTP steam turbine.

scholarly journals The effect of ethical leadership on employees’ empowerment: Field study at Al- Azhar University in Assuit - Arab Republic of Egypt: أثر القيادة الأخلاقية على تمكين العاملين: دراسة ميدانية على العاملين في جامعة الأزهر بأسيوط - جمهورية مصر العربية

2020 ◽  
Vol 4 (11) ◽  
Author(s):  
Abeer Mokhtar Sewify
Keyword(s):  
Human Resource Development ◽  
Leadership Style ◽  
Ethical Leadership ◽  
Leadership Behaviors ◽  
Pearson Correlation ◽  
Research Problem ◽  
Average Value ◽  
Effective System ◽  
Simple Regression Analysis ◽  
The Impact

Empowering employees is one of the recent administrative trends in human resource development, which is responsible for increasing productivity and improving quality and profitability in organizations. In order to permit the organization to achieve this, it needs to adopt an ethical leadership style that provides the appropriate climate to support the empowerment of workers. The study aimed to investigate the impact of ethical leadership on employees’ empowerment at Al- Azhar University in Assuit. The research problem of the current study was represented in the following inquiry: Does ethical leadership affects employees’ empowerment at Al- Azhar University in Assuit branch? The study relied on the descriptive-analytical approach. The researcher used Pearson correlation to measure the strength of association between the two variables of this study (ethical leadership and employees’ empowerment) and their dimensions and direction of the association. The researcher used simple regression analysis to test the hypotheses and relationships of the independent and dependent variables. The study sample included (317) people from Al- Azhar University where data was collected using a survey list prepared for the purpose of the study and only 255 questionnaires were received, rates about 80%. And the study reached several results; the most important of which is that the degree of exercise for the two study variables came with an average degree for each of them, where the average value for ethical leadership reached (3.57) and for employee empowerment the average was (3.53). Furthermore, it was found that there was a significant effect of ethical leadership behaviors on employees’ empowerment, as the value of (T) was (1.98), which is significant at the level of (0.01). The study recommended the need to support the values ​​of ethical leadership ​​and their basic dimensions through holding training courses and workshops to spread the tenet ​​of ethical leadership in the organization and its values as well. Last but not least, we recommend the organizations to adopt an effective system that permit them to monitor the application of the concept of employees’ empowerment.

scholarly journals Association between Adenoid-Nasopharyngeal Ratio and Tympanogram Width in Adenoid Hypertrophy Patients

2021 ◽  
Author(s):  
Muhammad Arif Sudianto Utama ◽  
Widodo Ario Kentjono ◽  
Haris Mayagung Ekorini
Keyword(s):  
Risk Factor ◽  
Pearson Correlation ◽  
Radiographic Examination ◽  
Adenoid Hypertrophy ◽  
Significance Level ◽  
Average Value ◽  
Middle Ear Pressure ◽  
Skull Radiography ◽  
Pearson Correlation Test ◽  
Male Patients

Abstract Introduction Adenoid hypertrophy is a change in adenoid size that can lead to obstruction the Eustachian tube and become a risk factor for otitis media effusion (OME) in children. Standard objective examination of adenoid hypertrophy uses adenoid-nasopharyngeal ratio (A-N ratio) based on correct lateral skull radiography. Adenoid hypertrophy is one of the factors causing OME in children. There is still much debate about the association between A-N ratio and tympanogram width (Tw). Determining the association of A-N ratio and Tw in adenoid hypertrophy patients. Methods Participants performed a true lateral radiographic examination using Fujioka method to determine A-N ratio, and Tw to determine middle-ear pressure. The distance between examination of A-N ratio and tympanogram examination was at maximum of ~1 week. The association between A-N ratio and Tw in patients with adenoid hypertrophy used the Pearson correlation test. This research employed significance level p < 0.05. Results Most participants were aged between 6 and 10 years (38.10%), male patients (57.14%), and the symptom most participants complained of was snoring during sleep (38.10%). Most participants had A-N ratio of 0.53 to 0.70 (61.90%) with an average of 0.60 ± 0.05. The average value of Tw measurement was 102.83 ± 50.03 daPa (r = 0.605; p < 0.001). Conclusion There is a significant association between A-N ratio base on true lateral radiographic examination and Tw in adenoid hypertrophy patients.

scholarly journals Determining an Improved Traffic Conflict Indicator for Highway Safety Estimation Based on Vehicle Trajectory Data

2021 ◽  
Vol 13 (16) ◽  
pp. 9278
Author(s):  
Ruoxi Jiang ◽  
Shunying Zhu ◽  
Hongguang Chang ◽  
Jingan Wu ◽  
Naikan Ding ◽  
...  
Keyword(s):  
Correlation Analysis ◽  
Traffic Safety ◽  
Pearson Correlation ◽  
Highway Safety ◽  
Lane Change ◽  
Trajectory Data ◽  
Average Value ◽  
Traffic Conflict ◽  
Vehicle Trajectory ◽  
Safety Estimation

Currently, several traffic conflict indicators are used as surrogate safety measures. Each indicator has its own advantages, limitations, and suitability. There are only a few studies focusing on fixed object conflicts of highway safety estimation using traffic conflict technique. This study investigated which conflict indicator was more suitable for traffic safety estimation based on conflict-accident Pearson correlation analysis. First, a high-altitude unmanned aerial vehicle was used to collect multiple continuous high-precision videos of the Jinan-Qingdao highway. The vehicle trajectory data outputted from recognition of the videos were used to acquire conflict data following the procedure for each conflict indicator. Then, an improved indicator Ti was proposed based on the advantages and limitations of the conventional indicators. This indicator contained definitions and calculation for three types of traffic conflicts (rear-end, lane change and with fixed object). Then the conflict-accident correlation analysis of TTC (Time to Collision)/PET (Post Encroachment Time)/DRAC (Deceleration Rate to Avoid Crash)/Ti indicators were carried out. The results show that the average value of the correlation coefficient for each indicator with different thresholds are 0.670 for TTC, 0.669 for PET, and 0.710 for DRAC, and 0.771 for Ti, which Ti indicator is obviously higher than the other three conventional indicators. The findings of this study suggest TTC often fails to identify lane change conflicts, PET indicator easily misjudges some rear-end conflict when the speed of the following vehicle is slower than the leading vehicle, and PET is less informative than other indicators. At the same time, these conventional indicators do not consider the vehicle-fixed objects conflicts. The improved Ti can overcome these shortcomings; thus, Ti has the highest correlation. More data are needed to verify and support the study.

Application of ADM1 for the simulation of anaerobic digestion of olive pulp under mesophilic and thermophilic conditions

2006 ◽  
Vol 54 (4) ◽  
pp. 149-156 ◽  
Author(s):  
H. Kalfas ◽  
I.V. Skiadas ◽  
H.N. Gavala ◽  
K. Stamatelatou ◽  
G. Lyberatos
Keyword(s):  
Anaerobic Digestion ◽  
Olive Oil ◽  
Volatile Fatty Acids ◽  
Two Phase ◽  
Solids Concentration ◽  
Thermophilic Conditions ◽  
Maximum Uptake Rate ◽  
Standard Values ◽  
Olive Pulp ◽  
Phase Production

The management of the wastewater originating from olive oil producing industries poses a serious environmental problem. Recently, two-phase production of olive oil has been developed, leading to almost complete elimination of the bulk of the generated wastewater and, is thus regarded as an environmentally friendly technology. However, the main waste stream (olive pulp) is a slurry material characterized by high solids concentration (∼30%), requiring stabilisation before its final disposal. The anaerobic digestion of olive pulp is studied in this work under mesophilic and thermophilic conditions in CSTR-type digesters. The digesters were fed with water-diluted (1:4) olive pulp at an HRT of 20 days and an OLR of 3.94 kg COD m−3 d−1. In order to study the process kinetics, the digesters were subjected to impulse disturbances of different substrates. The IWA anaerobic digestion model was used to simulate the reactors' response. Some key process parameters, such as the specific maximum uptake rate constants and the saturation constants for the volatile fatty acids degradation were estimated and compared with the standard values suggested by the ADM1.

scholarly journals Efficiency of cooling the water droplets within Jet-Film unit of cooling tower filler

2018 ◽  
Vol 224 ◽  
pp. 02079 ◽  
Author(s):  
Ilnur N. Madyshev ◽  
Oksana S. Dmitrieva ◽  
Andrey V. Dmitriev
Keyword(s):  
High Performance ◽  
Cooling Water ◽  
Cooling Towers ◽  
Recycled Water ◽  
Two Phase ◽  
Industrial Enterprises ◽  
Contact Stage ◽  
Contact Devices ◽  
Water Drops ◽  
Gas Liquid Flow

Researches of blocks of sprinklers of cooling towers with jet-film devices are presented. The conducted numerical studies allow us to estimate the influence of the design and operating parameters of the proposed contact device on the efficiency of the process of cooling the recycled water. The increase in the average gas velocity leads to a more intense flow of water drops and more efficient cooling. To achieve high performance, it is necessary to create zones of drip interaction of phases with droplet sizes up to 100 µm at relatively low speeds of two-phase gas-liquid flow. Under such conditions, the drop can be cooled by more than 10°C within one contact stage. The proposed sprinkler units with jet-film contact devices will be able to achieve a lower level of cooling water temperatures in the cooling towers of industrial enterprises at relatively low operating costs.

The evaluation of the composition dependence of fracture toughness of Al3Nb alloys by using micro-size fracture testing

MRS Advances ◽  
2017 ◽  
Vol 2 (26) ◽  
pp. 1405-1410
Author(s):  
Nobuhiro Matsuzaki ◽  
Ken-ichi Ikeda ◽  
Seiji Miura ◽  
Nobuaki Sekido ◽  
Takahito Ohmura
Keyword(s):  
Fracture Toughness ◽  
Single Crystal ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Two Phase ◽  
Fracture Testing ◽  
Average Value ◽  
Chevron Notch ◽  
Polycrystalline Alloys ◽  
Oxidation Resistant

ABSTRACTAl3Nb is known as a high oxidation resistant material, while it is quite brittle. As the fracture toughness of Al3Nb single crystal and its dependence on the composition are not obtained, the micro-sized fracture testing proposed by Suzuki et al. was performed. Al3Nb single crystal micron-order size cantilevers with a chevron-notch were fabricated in a grain of two-phase polycrystalline alloys by using FIB (Focused Ion Beam). From the load-displacement curves during the bending by a nanoindenter, the average value of fracture toughness of Nb-rich Al3Nb is evaluated to be 2.90 MPam1/2, while the fracture toughness of Al-rich Al3Nb is also evaluated to be 2.82 MPam1/2. From this result, the fracture toughness of Al3Nb is less dependent on its Al/Nb ratio. Furthermore the fracture toughness of Al3 (Nb, V) was evaluated to be 2.82 MPam1/2.The fracture toughness of Al3Nb is seemingly insensitive to V addition.

Compositional Simulation of Two-Phase Flows for Pipeline Depressurization

SPE Journal ◽  
2017 ◽  
Vol 22 (04) ◽  
pp. 1242-1253 ◽  
Author(s):  
Luigi Raimondi
Keyword(s):  
Numerical Solution ◽  
Mass Balance ◽  
Stokes Equations ◽  
Dynamic Pressure ◽  
Gas Production ◽  
Fluid Composition ◽  
Two Phase ◽  
Compositional Approach ◽  
Liquid Phases ◽  
System Pressure

Summary The simulation of multiphase flow, considered in the case of coexisting vapor and liquid phases, is an important topic in engineering for the design of oil-and-gas production and transportation facilities. This paper presents the development of a compositional approach for the dynamic calculation of multiphase flows in pipelines. This approach can be defined as “full compositional,” because the vapor and liquid phases are described by taking into account the chemical composition, presenting points of interest from both the theoretical and the practical points of view. Physical properties required are calculated at each integration timestep with the actual phase compositions instead of relying on property tables previously generated from a single constant fluid composition. With this approach, in the numerical solution of the conservative two-phase-flow equations, the congruency between the dynamic pressure, calculated by solving the Navier-Stokes equations at constant temperature, and the thermodynamic pressure of the system becomes a critical constraint. In the numerical solution, the overall mass balance defined by means of the vapor- and liquid-phase densities is verified with respect to the mass balance of each chemical component involved, and the system pressure obtained from the solution of the momentum equations is always compared with the thermodynamic value defined by mass balance. Of the numerous test cases created for model validation, three of them (focused on fast depressurizations) are presented and discussed. Similar examples are not available in the literature as solutions of the current “state-of-the-art” commercial pipeline simulators.

Research of Corrosion and Protection on Boiler and Pipelines by Condensing Water

2012 ◽  
Vol 239-240 ◽  
pp. 1589-1595
Author(s):  
Chang Shan Huang ◽  
Jin Ying Wu ◽  
Hui Wu Xu ◽  
Yu Shan Cheng ◽  
Min Zhang
Keyword(s):  
Carbon Dioxide ◽  
Electrochemical Method ◽  
Cooling Water ◽  
Corrosion Process ◽  
Steam Condensation ◽  
Recycling Process ◽  
Water Conductivity ◽  
Circulating Cooling Water ◽  
Management Flow ◽  
Pipeline Corrosion

Boiler and pipeline that using steam condensation water will be eroded when the steam condensation water absorb dissolved oxygen and carbon dioxide in the production and recycling process. In order to solve this problem, a preferably management flow and process were developed to slow down the Boiler and pipeline corrosion process by analyzing the microstructure of corrosive Boiler and pipeline with a Electrochemical method. Firstly, rinse the Boiler and pipeline with 5% citric acid at about 90 oC, after that process adding 4~6mg/L anti-filthy corrosion inhibitor to the steam condensation water and adjusting pH at 8.0~9.5 by 30% sodium hydroxide or 50% sulfuric acid. At the same time maintenance water conductivity below 1200μs/cm by discharging condensation water. This method will play an import part in managing Circulating cooling water.

Experimental Study of Heat Transfer in Horizontal Gas-Liquid Intermittent Flow

2010 ◽  
Author(s):  
Ivan Noville ◽  
Antonio C. Bannwart
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Flow Pattern ◽  
Mechanistic Model ◽  
Cooling Water ◽  
Intermittent Flow ◽  
Production Flow ◽  
Two Phase ◽  
Experimental Apparatus

The present work is aimed at the experimental measurement of the two-phase heat transfer coefficient in the intermittent horizontal gas-liquid flow pattern, as well as its comparison with some existing correlations. The intermittent flow pattern is very common in oil production flow lines. In order to reach this objective an experimental apparatus was built, consisting of a 5 cm i.d., 6.0 m long pipe test section fed up with several air-water mixtures pre-heated at different inlet temperatures. Heat transfer was accomplished by surrounding the pipe with a cooling water jacket under various inlet flow rates and temperatures, flowing co-currently with the central pipe gas-liquid mixture. The heat transfer coefficient was experimentally determined and compared with four published correlations. Among then, a mechanistic model was selected for further improvement, with very satisfactory results.

scholarly journals Hubungan antara tinggi dan panjang mandibula di radiograf panoramik dengan kadar kalsium pada pasien lanjut usia

2021 ◽  
Vol 5 (1) ◽  
pp. 13
Author(s):  
Ichda Nabiela Amiria Asykarie ◽  
Lusi Epsilawati ◽  
Ria Noerianingsih Firman ◽  
Farina Pramanik
Keyword(s):  
Significant Relationship ◽  
Pearson Correlation ◽  
The Elderly ◽  
Cross Sectional ◽  
Test Analysis ◽  
Panoramic Radiographs ◽  
Correlation Test ◽  
Average Value ◽  
Pearson Correlation Test ◽  
Mandibular Body

Objectives: The aim of this research is to know about the correlation between calcium levels and mandibular height and length in elderly patients from panoramic radiographs. Materials and Methods: This study was a cross-sectional observational study, using 15 panoramic radiographs of patients aged 60-80 years, where each subject is taken calcium levels. Radiographs were analyzed to measure the length of the mandibular body and the height of the mandibular ramus. ImageJ software is used as a measuring tool, and the results are then correlated with the Pearson correlation test analysis. Results: This study obtained the average result for mandibular length was ± 10 cm and for mandibular height was ± 7 cm, while the calcium value showed an average value of ± 8.7-10 mg/dl. Pearson correlation test showed no significant relationship between mandibular length and height and calcium levels in the elderly. Conclusion: The conclusion drawn was that there is no significant relationship between mandibular height and length on calcium levels in the elderly as assessed by panoramic radiographs.

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