The 3-D viscous flow CFD analysis of the propeller effect on an advanced ducted propeller subsonic inlet

A time marching Navier-Stokes code called PARC3D was used to study the 3-D viscous flow associated with an advanced ducted propeller (ADP) subsonic inlet at take-off operating conditions. At a free stream Mach number of 0.2, experimental data for the inlet-with-propeller test model indicated that the airflow was attached on the cowl windward lip at an angle of attack of 25 degrees became unstable at 29 degrees, and separated at 30 degrees. An experimental study with a similar inlet and with no propeller (through-flow) indicated that flow separation occurred at an angle of attack a few degrees below the value observed when the inlet was tested with the propeller. This tends to indicate that the propeller exerts a favorable effect on the inlet performance. During the through-flow experiment a stationary blockage device was used to successfully simulate the propeller effect on the inlet flow field at angles of attack. In the present numerical study, this flow blockage was modeled via a PARC3D computational boundary condition (BC) called the screen BC. The principle formulation of this BC was based on the one-and-half dimension actuator disk theory. This screen BC was applied at the inlet propeller face station of the computational grid. Numerical results were obtained with and without the screen BC. The application of the screen BC in this numerical study provided results which are similar to the results of past experimental efforts in which either the blockage device or the propeller was used

Analysis of an advanced ducted propeller subsonic inlet

A time marching Navier-Stokes code called PARC (PARC2D for 2-D/axisymmetric and PARC3D for 3-D flow simulations) was validated for an advanced ducted propeller (ADP) subsonic inlet. The code validation for an advanced ducted propeller (ADP) subsonic inlet. The code validation was implemented for a non-separated flow condition associated with the inlet operating at angles-of-attack of 0 and 25 degrees. The inlet test data were obtained in the 9 x 15 ft Low Speed Wind Tunnel at NASA Lewis Research Center as part of a cooperative study with Pratt and Whitney. The experimental study focused on the ADP inlet performance for take-off and approach conditions. The inlet was tested at a free stream Mach number of 0.2, at angles-of-attack between O and 35 degrees, and at a maximum propeller speed of 12,000 RPM which induced a corrected air flow rate of about 46 lb/sec based on standard day conditions. The computational grid and flow boundary conditions (BC) were based on the actual inlet geometry and the funnel flow conditions. At the propeller face, two types of BC's were applied: a mass flow BC and a fixed flow properties BC. The fixed flow properties BC was based on a combination of data obtained from the experiment and calculations using a potential flow code. Comparison of the computational results with the test data indicates that the PARC code with the propeller face fixed flow properties BC provided a better prediction of the inlet surface static pressures than the predictions when the mass flow BC was used. For an angle-of-attack of 0 degrees, the PARC2D code with the propeller face mass flow BC provided a good prediction of inlet static pressures except in the region of high pressure gradient. With the propeller face fixed flow properties BC, the PARC2D code provided a good prediction of the inlet static pressures. For an angle-of-attack of 25 degrees with the mass flow BC, the PARC3D code predicted statis pressures which deviated significantly from the test data; however, with the fixed flow properties BC, a good comparison with the test data was obtained

Analytical and experimental studies of a short compact subsonic diffuser for a two-dimensional supersonic inlet

An experimental study of a two-dimensional supersonic inlet with a short compact subsonic diffuser, length to exit diameter (dl/d) ratio of 1.25, was conducted to investigate the impact of the short diffuser on inlet performance at low speeds and to assess the diffuser subsonic performance for a simulated diffuser flow corresponding to high-speed inlet conditions near the design flight Mach number of 2.2. For the low-speed testing, a drooped lip was employed to improve the inlet performance at a high angle of attack. For the simulated high-speed testing, air was blown through slots or discrete nozzles as an active boundary-layer control. The results from the low-speed performance test were compared with the results from a previous test program on the same inlet with a long subsonic diffuser (dl/d = 4.5). The comparison indicates that inlet recovery was not affected by the use of the short diffuser for either the baseline (no droop) or the drooped cowl lip configuration. However, the inlet baseline distortion for the short diffuser configuration was substantially higher than for the long diffuser. A comparison of the two configurations with a 70 deg drooped lip showed no significant difference in distortion. For the portion of the experimental program in which diffuser conditions for high-speed flight were simulated, diffuser-induced flow separation occurred. This separation was predicted from an analytical study that used the Hess potential flow panel method and the Herring two-dimensional boundary-layer analysis computer codes. The flow separated mainly on the diffuser ramp. Subsequent tests in which boundary-control systems were utilized showed that blowing with either slots or discrete nozzles could suppress the flow separation in the short subsonic diffuser, thereby substantially improving the diffuser performance

The effects of HR strategic partnerships with business on organisational performance : experience of the Cambodian banking sector

Fast changing globalisation, technological advancement, social and demographic changes and increasing international competition require Human Resource practitioners to play a completely new role as strategic partners to the business. HR leaders are required to provide consulting and strategic support by taking a pro-active, long-term, mission-related approach to human resource management initiatives to achieve organisational goals through people with the use of HR strategies and practices. Empirical studies carried out in the field of strategic human resource management suggest that HR strategic partnerships bring positive impacts to the business resulting in an improvement in organisational excellence. This study employs a mixed method of qualitative and quantitative approaches to examine the research question; whether or not the current HR strategic partnerships in the business are effective in the Cambodian banking sector, and, what is the extent of the effectiveness of the partnerships on the organisational performance? Questionnaires and semi-structured interviews were used as data collection techniques. A total of one hundred supervisors, managers and line managers took part in the survey while ten HR Managers and HR Business Partners (HR BPs) participated in the interviews. The findings of the study revealed that effective HR strategic partnering affects organisational performance positively and that HR strategic partners play an increasingly important role in helping the firm to achieve its business objectives. In addition, it was found out that current HR practices in the Cambodian banking sector were up to expectation in terms of being strategic; however, due to a number of challenges in performing their strategic role, current HR leaders could only achieve a moderate extent of HR effectiveness, leaving several areas for improvement. Findings on the skillset required from HR business partners revealed that in order to effectively perform an HR strategic role, HR business partners must possess business understanding and financial acumen, coupled with a wide range of HR competencies and personal qualities. It is strongly recommended that HR business partners must work in partnership with the business to ensure positive outcomes

Hubungan Kualitas Tidur dengan Kesejahteraan Psikologis Lansia di Panti Pelayanan Sosial Lanjut Usia Dewanata Cilacap

Latar belakang: Kesejahteraan psikologis merupakan suatu hal yang penting bagi lansia. Hal tersebut mempengaruhi kondisi kesehatan lain bagi lansia. Salah satu masalah yang mungkin dapat menyebabkan kesejahteraan psikologis lansia menurun yaitu kualitas tidur. Kualitas tidur yang buruk pada lansia menyebabkan berbagai permasalahan kesehatan baik fisik maupun psikologis mereka. Penelitian ini bertujuan untuk mengetahui Hubungan Kualitas Tidur dengan Kesejahteraan Psikologis Lansia di Panti Pelayanan Sosial Lanjut Usia Dewanata Cilacap. Metodologi: Penelitian ini merupakan desain komparasi dengan pendekatan cross sectional yang dilakukan pada lansia di Panti Pelayanan Sosial Lanjut Usia (PPSLU) Dewanata Cilacap. Teknik sampling yang dipakai oleh peneliti adalah total sampling yaitu dengan mengambil keseluruhan jumlah populasi yang terdapat di PPSLU Dewanata Cilacap yaitu 100 lansia. Analisis data penelitian ini menggunakan uji Chi Square. Hasil: Hasil penelitian ini menunjukkan mayoritas 72.1% responden berusia antara 60-74 tahun, 52.5% berjenis kelamin perempuan, dan 39.3% berpendidikan SD (Sekolah Dasar), 45.9% lansia memiliki kualitas tidur yang buruk, 29.5% kualitas tidur sangat baik, dan 24.6% kualitas tidur baik, 55.7% memiliki kesejahteraan psikologis yang tinggi, dan 44.3% kesejahteraan psikologi rendah. Hasil uji Chi Square menunjukkan nilai p=0.00. Kesimpulan: Terdapat hubungan bermakna antara kualitas tidur dengan kesejahteraan psikologis lansia di PPSLU Dewanata Cilacap

Effect of Calcium on the Growth of Melon (Cucumis melo L.)

Melon (Cucumis melon L.) is an important crop for the world economy, and it is one of the most valuable crops in the market. The cultivation of melon in Cambodia is still low due to the unclear use of varieties and the inappropriate cultivation techniques that cannot achieve high yields. This is the reason why this research is conducted. The objectives of this research are: 1. to compare the growth of melon varieties with calcium in Svay Rieng province condition, 2. to study the appropriate level of calcium fertilizer on melon yield in the supplementary stage, and 3. to study the fruit quality of the five melon varieties. This experiment was arranged into Randomized Complete Block Design (RCBD) with 4 replications and 20 treatments equivalent to 80 plots totallyat the Agricultural Station of Svay Rieng University. The results showed that the application of calcium fertilizer and foliar spraying once every 7 days resulted in the highest growth of melon plants. The use of different varieties showed that the melon varieties V4 (Lady Green = 547) and V2 (Lady Gold = 518) received the highest number of seeds. Thus, in summary, comparing the growth of 5 melon cultivars with 4 levels of calcium fertilizer, the results showed that the application of calcium fertilizer and leaf spray every 4 days, every 7 days, made the melon crop. Growth, yield, and fruit quality are excellent. The use of different varieties showed that only the melon varieties V4, V1, and V2 are the best

The potential impact of climate change on 'Nezara viridula' (L.) (Hemiptera: Pentatomidae) and its parasitoid, 'Trichopoda giacomelii' Blanchard (Diptera: Tachinidae) in Cambodia and Australia: Ecological, behavioural and physiological assessments

'Nezara viridula' (L.) (Hemiptera: Pentatomidae) is a cosmopolitan, polyphagous heteropteran insect that causes economic damage to many crop species worldwide. Despite several interventions attempts, 'N. viridula' has remained a significant pest in certain regions of Cambodia and eastern Australia, particularly those where soybean and nut crops are cultivated. Recently, 'Trichopoda giacomelii' Blanchard (Diptera: Tachinidae), a species native to Argentina was established in Australia as an effective biological control agent for 'N. viridula' in one instance. However, with predicted climate change, the range of the pest could expand or change and the relationship between the pest and the parasitoid could also change in response to altered temperature and precipitation regimes. Changed climatic conditions could affect the pest status and geographic range of 'N. viridula' as well as the efficacy of the parasitoid. Climate change will potentially affect the interactions between factors such as temperature, humidity, light, food, and the wellbeing of the pest and the parasitoid and the relationship between the two. The aims of this study were (i) to evaluate the sampling methods of arthropods on soybean crops in Cambodia, in terms of accuracy of the use of the two main sampling methods: sweep netting and beat sheeting; (ii) to measure the effect of changed temperature and moisture regimes on 'N. viridula' and 'T. giacomelii' life cycles in populations from contrasting climatic regimes (Breeza and Grafton); (iii) to measure the effect of changed temperature and moisture regimes on the ability of the parasitoids to parasitize 'N. viridula'; and (iv) to investigate the various physiological variables of 'N. viridula' under the stress of temperature

Pendidikan Kesehatan tentang Sikap Tubuh Ergonomis dan Pola Aktivitas untuk mencegah Muskuloskeletal Disorders pada Remaja

Latar belakang: Pandemi COVID 19 selama kurun waktu dua tahun ini telah menghentikan banyak aktivitas manusia, termasuk remaja yang harus  belajar secara online di rumah. Aktivitas fisik yang kurang adekuat dan juga sikap kerja tubuh selama beraktivitas di rumah yang tidak memperhatikan prinsip ergonomis dalam jangka waktu yang lama, memberikan dampak terhadap kesehatan terutama munculnya gangguan muskuloskeletal mulai dari yang ringan-sedang pada remaja. Tujuan: melakukan pendidikan kesehatan tentang sikap tubuh ergonomis dan pola hidup sehat untuk mencegah terjadinya musculoskeletal disorders (MSDs). Metode: Pengabdian kepada masyarakat berbasis riset dilakukan dengan metode pendidikan kesehatan dengan topik sikap tubuh ergonomis dan pola aktivitas/olahraga dalam rangka mencegah gangguan tulang dan sendi. Peserta yang hadir sebanyak 50 orang. Hasil : Tingkat pengetahuan remaja tentang bagaiman pola aktivitas dan olahraga yang ideal untuk remaja berada pada tingkat sedang yaitu sebanyak 41 anak (82%) dan tingkat pengetahuan tentang sikap ergonomis tubuh dalam aktivitas sehai-hari dalam mencegah musculoskeletal disorder sudah mencapai 96% tingkat pengetahuan yang tinggi. Kesimpulan: Pendidikan kesehatan tentang sikap tubuh ergonomis sangat penting dilakukan pada remaja untuk membekali pengetahuan, sikap dan perilaku sikap tubuh ergonomis yang baik dan benar dalam aktivitas sehari-hari sehingga mencegah terjadinya MSDs. Dengan terjaganya kesehatan otot, tulang, dan sendi maka kualitas hidup dan produktivitas remaja akan terpelihara bahkan meningkat.   Kata kunci: Ergonomi, sikap tubuh, musculoskeletal disorders, remaj

Factors Associated with Negative Direct Sputum Examination in Asian and African HIV-Infected Patients with Tuberculosis (ANRS 1260)

OBJECTIVE: To identify factors associated with negative direct sputum examination among African and Cambodian patients co-infected by Mycobacterium tuberculosis and HIV. DESIGN: Prospective multicenter study (ANRS1260) conducted in Cambodia, Senegal and Central African Republic. METHODS: Univariate and multivariate analyses (logistic regression) were used to identify clinical and radiological features associated with negative direct sputum examination in HIV-infected patients with positive M. tuberculosis culture on Lowenstein-Jensen medium. RESULTS: Between September 2002 and December 2005, 175 co-infected patients were hospitalized with at least one respiratory symptom and pulmonary radiographic anomaly. Acid-fast bacillus (AFB) examination was positive in sputum samples from 110 subjects (63%) and negative in 65 patients (37%). Most patients were at an advanced stage of HIV disease (92% at stage III or IV of the WHO classification) with a median CD4 cell count of 36/mm³. In this context, we found that sputum AFB negativity was more frequent in co-infected subjects with associated respiratory tract infections (OR = 2.8 [95%CI:1.1-7.0]), dyspnea (OR = 2.5 [95%CI:1.1-5.6]), and localized interstitial opacities (OR = 3.1 [95%CI:1.3-7.6]), but was less frequent with CD4 ≤ 50/mm³ (OR = 0.4 [95%CI:0.2-0.90), adenopathies (OR = 0.4 [95%CI:0.2-0.93]) and cavitation (OR = 0.1 [95%CI:0.03-0.6]). CONCLUSIONS: One novel finding of this study is the association between concomitant respiratory tract infection and negative sputum AFB, particularly in Cambodia. This finding suggests that repeating AFB testing in AFB-negative patients should be conducted when broad spectrum antibiotic treatment does not lead to complete recovery from respiratory symptoms. In HIV-infected patients with a CD4 cell count below 50/mm3 without an identified cause of pneumonia, systematic AFB direct sputum examination is justified because of atypical clinical features (without cavitation) and high pulmonary mycobacterial burden