Exploration of ocean current energy allows for the development of turbines as the primary conversion device. Turbine technologies have been developed in various types, including bio-inspired ...turbines, such as the humpback whale fluke turbine. In this study, the achievement of a humpback whale fluke turbine is investigated by applying various forms of foil, both symmetric and asymmetric, to obtain the appropriate foil profile. Symmetric foils were represented by NACA 0012, NACA 0018, and NACA 0021, while asymmetric foils were represented by NACA 4312, NACA 4512, and NACA 4712 foils. Simulations were performed using QBlade software, which was developed based on the DMST theory. In general, symmetric foils have a more stable performance than asymmetric foils because they produce a better performance at positive and negative angles of attack. This result is also supported by a review of efficiency and self-starting capability where symmetric foils have significantly higher CP values and positive CQ along the azimuth angle than asymmetric foils. Finally, NACA 0021 foil is recommended for a humpback whale fluke turbine based on its efficiency and self-starting capability.
Efficiency and self-starting capability performances are the main problems in vertical axis turbines. By purposing improves its performance, vertical axis turbines have been developed with various ...models. One of the developments of this model is to design the turbine blades into unique shapes. This research aims to determine the performance of some unique blade vertical axis turbines conditioned on the same parameters, especially if applied in a marine environment. Turbines with helical blade (HB), eggbeater-shaped blade (ESB), diamond-shaped blade (DSB), Y-shaped blade (YSB), and arrow-shaped blade (ASB) were investigated based on efficiency and self-starting capability using QBlade software. Good performance symmetrical foils such as NACA 634021 are also applied to each turbine. The simulation results show that from the aspect of efficiency performance, turbine ASB HB ESB DSB YSB. Meanwhile, in the aspect of self-starting capability performance, the sequence is similar to efficiency performance, based on the two approaches applied. The highest efficiency achieved by the ASB turbine is 0.391 at the lowest tip speed ratio of λ = 4. The ASB turbine also achieves the best self-starting performance, which has a minimum static torque coefficient of 0.00155 and can produce the required power at the lowest marine current speed of 0.806 m/s. This performance brings the ASB turbine to produce a rated power of 52.52 kW, or more than twice the power production of the lowest efficiency turbine and has an average power gain of 3.75 kW per 0.2 m/s.
Abstract— Covid -19, a virus strain and a member of family with known member as Severe Acute Respiratory Disease (SARS) or Middle East Respiratory Syndrome (MERS), but having a potentially lethal ...differences in not readily recognized by our immunity. Classified as betacoronavirus, with incubation period up to 14 days, the sign and symptoms can be highly variable, from asymptomatic to mild to criticalin the form of severe pneumonia. Almost half the persons infected did not show any symptoms, but in cases of people with comorbidities such as advanced age, pregnancy, obesity or other certain diseases, could increase the likelihood of morbidity and even potentially fatal. Covid-19 has spread globally, including Indonesia, with a potentially increased number of cases, prevention in covid-19 protocol is a necessity. Keywords: Covid-19, SARS, symptoms, variable, prevention
Abstrak— Covid-19, yang sebelumnya dikenal sebagai virus strain dari kelompok family yang sama dengan Severe Acute Respiratory Disease (SARS) atau Middle East Respiratory Syndrome (MERS), tapi memiliki fatalitas yang secara potensial lebih tinggi, karena bersiafat novel bagi sistem imunitas kita. Termasuk betacoronavirus, dengan masa inkubasi sampai dengan 14 hari, tanda dan gejala penyakit bisa sangat bervariasi, mulai dari asimtomatik, ringan sampai berat, dalam bentuk pneumonia berat. Hamper separuh penderita yang terinfeksi tidak menunjukkan gejala sama sekali, tapi pada penderita dengan komorbiditas seperti usia lanjut, kehamilan, obesitas atau penyakit kronis tertentu, resiko moribiditas dan mortalitas dapat meningkat. Covid-19 saat ini sudah menyebar ke seluruh dunia, termasuk Indonesia, dengan adanya potensi kenaikan kasus lebih banyak, pencegahan dalam bentuk protocol covid-19 bersifat mutlak diperlukan. Kata kunci: Covid-19, SARS, gejala, bervariasi, pencegahan
Salah satu cara memanfaatkan sumber energi terbarukan adalah dengan menggunakan sel surya yang mengubah energi cahaya matahari menjadi energi listrik. Sebuah converter umumnya diperlukan untuk ...menyesuaikan tegangan keluaran sel surya dengan kebutuhan aplikasinya. Salah satu jenis konverter yang dapat digunakan yaitu konverter boost, yang dapat menghasilkan tingkat tegangan pada keluarannya lebih tinggi dari masukannya. Keluaran dari sel surya yang bervariasi tergantung pada perubahan iradiasi cahaya matahari menjadi masukan bagi konverter. Pada penelitian ini metode pengendalian sliding mode control (SMC) dimanfaatkan untuk mengurangi osilasi pada tegangan keluaran konverter boost. Penelitian dilakukan dengan cara simulasi menggunakan MATLAB/Simulink pada kondisi sistem pengendalian loop terbuka dan loop tertutup. Nilai settling time dan selisih tegangan keluaran saat sebelum terjadi gangguan dan setelah terjadi gangguan berupa tegangan masukan yang bervariasi dan beban yang bervariasi dianalisis.
Makalah ini mendiskusikan tentang analisis tegangan sag dalam sistem distribusi. Tegangan sag disebabkan gangguan hubung singkat 1 fasa ke tanah. Tegangan sag memberikan dampak kerusakan pada beban ...Pujon. Tegangan sag diatasi dengan kompensasi tegangan dari salah satu Costum Power Device paling efektif yaitu Dynamic Voltage Restorer (DVR). Metode kontrol ANN ditambahkan dalam Kontrol Hystereisis diusulkan untuk meningkatkan kinerja DVR mengkompensasi tegangan beban. Hasil simulasi menunjukan bahwa DVR mampu mengkompensasi tegangan beban terhadap tegangan sag dari gangguan hubung singkat fasa ke tanah rata-rata sebesar 98.73%, gangguan 2 fasa ke tanah rata-rata sebesar 99.07% dan gangguan 3 fasa ke tanah rata-rata sebesar 99.34%.
Penelitian ini bertujuan untuk mengetahui efek dari kombinasi latihan ladder drill quick feet dan bunny hop dalam meningkatkan kecepatan dan kelincahan. Metode penelitian yang digunakan adalah quasi ...eksperimen dengan desain randomized pre and post test design. Teknik purposive sampling digunakan untuk menentukan subjek penelitian dengan kriteria: 1) siswa SMP Negeri 1 Jogoroto yang mengikuti ekstrakurikuler bola voli, 2) laki-laki, 3) berusia 14-16 tahun. Jumlah seluruh subjek penelitian sebanyak 16 orang yang dibagi menjadi dua kelompok secara acak. Tiap kelompok terdiri dari delapan orang. Kelompok 1 (LD) diberi intervensi melakukan kombinasi latihan ladder drill dan kelompok 2 (Konvensional) melakukan latihan konvensional. Frekuensi latihan dilakukan sebanyak 18 pertemuan dengan rincian seminggu 3 kali, selama 6 minggu. Instrumen penelitian yang digunakan adalah sprint 30 m dan agility t test. Teknik analisis yang digunakan adalah paired sample t-test dan independent t-test. Hasil penelitian menunjukkan masing-masing kelompok dapat meningkatkan kecepatan dan kelincahan yang dibuktikan dengan nilai sig. < 0,05. Selain itu, ada perbedaan yang signifikan antara kelompok LD dengan konvensional dalam meningkatkan kecepatan dan kelincahan dengan nilai sig. < 0,05. Kesimpulannya adalah kombinasi latihan ladder drill quick feet dan bunny hop dapat meningkatkan kecepatan dan kelincahan secara signifikan dibandingkan latihan konvensional.
Penelitian ini bertujuan untuk mengetahui pengaruh pelatihan wall squat dan lungs terhadap kekuatan otot tungkai dan kemampuan dolphin kick saat under water pada renang gaya bebas 50 meter. Desain ...penelitian pada penelitian berikut adalah ekperiment semu (quasi experiment). Rancangan penelitian ini memakai Non-Randomized Control Group Pre Test-Post Test Design. Program latihan wall squat dan lunges dilakukan selama 6 minggu dengan intensitas 40% - 60% dan meningkat sesuai program setiap 2 minggu sekali dengan jumlah set sebanyak 3 set, waktu istirahat selama 1 – 2 menit antar set. Berdasarkan uji LSD menunjukkan bahwa pelatihan wall squat lebih meningkatkan kekuatan otot tungkai dan kemampuan dolphin kick daripada pelatihan lungs dan eklompok kontrol. Pelatihan wall squat adalah pelatihan yang efektif guna meningkatkan kekuatan otot tungkai dan kemampuan dolphin kick saat under water renang 50 meter gaya bebas.Kata kunci: wall squat, lungs, kekuatan otot tungkai, dolphin kick.
Motility of pathogenic protozoa depends on flagella (synonymous with cilia) with axonemes containing nine doublet microtubules (DMTs) and two singlet microtubules. Microtubule inner proteins (MIPs) ...within DMTs influence axoneme stability and motility and provide lineage-specific adaptations, but individual MIP functions and assembly mechanisms are mostly unknown. Here, we show in the sleeping sickness parasite Trypanosoma brucei, that FAP106, a conserved MIP at the DMT inner junction, is required for trypanosome motility and functions as a critical interaction hub, directing assembly of several conserved and lineage-specific MIPs. We use comparative cryogenic electron tomography (cryoET) and quantitative proteomics to identify MIP candidates. Using RNAi knockdown together with fitting of AlphaFold models into cryoET maps, we demonstrate that one of these candidates, MC8, is a trypanosome-specific MIP required for parasite motility. Our work advances understanding of MIP assembly mechanisms and identifies lineage-specific motility proteins that are attractive targets to consider for therapeutic intervention.
This study investigates the relationship between dual-role conflict and job stress among married female nurses working at Hospital X in Magelang. The hospital's policy flexibility in the new normal ...era aims to enhance healthcare quality, but this also leads to job stress among nurses due to heavy workloads. Interviews with ten married nurses revealed various stress-related issues, highlighting the need for further research. The study defines job stress as the body's response to high job demands and dual-role conflict as the interference between job and family roles. A total of 90 female nurses participated in the study, with data collected via questionnaires using Likert scales. Descriptive statistics showed high levels of dual-role conflict and moderate job stress among participants. Validity and reliability tests confirmed the suitability of the measurement tools used. Pearson correlation analysis revealed no significant relationship between dual-role conflict and job stress (r = -0.073, p > 0.05). The findings suggest that while dual-role conflict levels are high, they do not significantly contribute to job stress among the nurses. Factors such as manageable role conflicts and supportive spouses may mitigate the impact. This study aligns with previous research indicating that dual-role conflict does not necessarily increase job stress among working women. Despite limitations, the study underscores the importance of considering various factors influencing job stress and suggests that other elements may play a more critical role in affecting the stress levels of female nurses at Hospital X.
Every company strives to increase efficiency and effectiveness to adapt to competitive developments. One of the efforts made is to prepare employees to compete at work. Career adaptability is ...necessary for employees to support effective performance, especially for early career employees. Therefore, early career employees need good self-efficacy to support career adaptability. This research aims to determine the relationship between self-efficacy and career adaptability in early-career employees at PT. XYZ. The method used is quantitative with a simple correlational design. Data collection used non-probability sampling with a saturated sampling technique, carried out using a Google form distributed to all PT. XYZ. The research scale consists of the General Self-Efficacy Scale (α =0.932) and the Career Adapt-Abilities Scale (α= 0.969). The Spearman Rho correlation test obtained a coefficient value of 0.841 with p(Sig.) = 0.000 (p<0.01) shows that self-efficacy positively relates to career adaptability in early-career employees. Research on self-efficacy and career adaptability in early career employees is expected to provide important information that can be used to improve employee development practices, organizational policies, and future academic literature.Keywords: Self-efficacy; Career Adaptability; Early Career
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