Heat transfer characteristics and entropy generation for wing-shaped-tubes with longitudinal external fins in cross-flow

Sayed Ahmed E. Sayed Ahmed,Osama M. Mesalhy,Mohamed A. Abdelatief 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.6

A numerical study is conducted to clarify heat transfer characteristics, effectiveness and entropy generation for a bundle of wingshaped-tubes attached to Longitudinal fins (LF) at downstream side. The air-side Re a ranged from 1.8 x 10 3 to 9.7 x 10 3 . The fin height (h f ) and fin thickness (δ) have been changed as: (2 mm ≤ h f ≤ 12 mm) and (1.5 mm ≤ δ ≤ 3.5 mm). The analysis of entropy generation is based on the principle of minimizing the rate of total entropy generation that includes the generation of entropy due to heat transfer and friction losses. The temperature field around the wing-shaped-tubes with (LF) is predicted using commercial CFD FLUENT 6.3.26 software package. Correlations of Nu a , St a , and Bejan number (Be), as well as the irreversibility distribution ratio (Φ) in terms of Re a and design parameters for the studied bundle are presented. Results indicated that, installing fins with heights from 2 to 12 mm results in an increase in Nu a from 11 to 36% comparing with that of wing-shaped tubes without fins (NOF). The highest and lowest values of effectiveness (ε) at every value of the considered Re a range are occurred at h f = 6 mm and (NOF), respectively. The wing-shaped-tubes heat exchanger with h f = 6 mm has the highest values of (ε), efficiency index (η) and area goodness factor (G a ) and also the lowest values of Φ and hence the best performance comparing with other arrangements. The minimum values of Φ are occurred at h f = 6 mm. (Be) decreases with increasing Re a for all studied h f . The heat transfer irreversibility predominates for (1800 ≤ Re a ≤ 4200) while the opposite is true for (6950 < Re a ≤ 9700). δ has negligible effect on Nu a and heat transfer irreversibility. Comparisons between the experimental and numerical results of the present study and those, previously, obtained for similar available studies showed good agreements.

Determining Dimensions of Job Satisfaction among Employees: Evidence from Commercial Bank Industries in Bangladesh

Md. Sayed UDDIN(Md. Sayed UDDIN ),Md. Atikur RAHAMAN(Md. Atikur RAHAMAN ),Wasib Bin LATIF(Wasib Bin LATIF ) 한국유통과학회 2023 The Journal of Asian Finance, Economics and Busine Vol.10 No.2

Since the banking industry relies so heavily on strong customer-staff interactions, measuring employee job satisfaction has become a critical problem. To achieve benefits for both individuals and organizations, it is crucial to foster and ensure employee job satisfaction. The main objective of this study is to determine the influencing factors of employees’ job satisfaction in commercial banks in Bangladesh. This study focused on some significant factors such as employee empowerment, job security, management support, and attractive compensation in an organization. In terms of research purpose, non-probability convenience sampling has been used, and the study is quantitative in nature. For data collection purposes, an online survey questionnaire was prepared based on previously published articles. The targeted population was the bank employees of commercial banks in Bangladesh where the final sample size was n = 200. For analyzing the collected data, SPSS 26.0 version has been used to test the study model and the proposed hypotheses. This study also shows that employee empowerment, job security, management support, and attractive compensation have positive and significant effects on employees’ job satisfaction at the workplace. Finally, this study has offered some extraordinary directions and implications for future research on commercial bank authorities in Bangladesh.

Separation axioms in (L,M)-fuzzy topology (L,M)-fuzzy convexity spaces

Osama Rashed Sayed,EL-Sayed EL-Sanousy,Yaser Hassanein Ragheb Sayed 원광대학교 기초자연과학연구소 2021 ANNALS OF FUZZY MATHEMATICS AND INFORMATICS Vol.21 No.1

In this paper, we dene r-L-fuzzy closed convex sets and r-L-fuzzy closed neighbourhoods in an (L, M)-fuzzy topology (L, M)-fuzzy convexity spaces. Also, r-L-fuzzy neighbourhood separation properties r- L-FNSi were studied where i = f0, 1, 2, 3, 4g. In addition, we also study the invariance or otherwise of these separation properties under subspace and product.

Alleviation of salt stress in  Triticum aestivum by biopriming with  Phanerochaete chrysosporium

Hanan El-Sayed Dief,El-Sayed A. Hashem,Salwa Fawzan,Ashraf S. A. El-Sayed 한국작물학회 2021 Journal of crop science and biotechnology Vol.24 No.1

Wheat is one of the most important cereals, vital basic crop in Egypt, covering approximately 32.6% of the total winter land. However, sensitivity to abiotic stress especially salinity is one the major current hurdles that reduce the global yield of this crop. Plant biopriming with fungi is the recent technology that might alleviate the salt stress eff ect. Thus, the objective of this work was to examine the eff ect of Triticum aestivum grains biopriming with Phanerochaete chrysosporium on the response of wheat to salt stress. From the physiological and biochemical parameters, biopriming of wheat grains with P. chrysosporium significantly alleviates the salt stress and markedly increases the growth parameters, photosynthetic pigments and osmolytes (soluble sugars, soluble protein and proline) contents. In addition, it alleviates the oxidative damage, as indicated by the lower accumulation of malondealdehyde and increasing the activity of antioxidant enzymes; superoxide dismutase, catalase, and ascorbate peroxidase in wheat seedlings. Results indicate the potential of using P. chrysosporium biopriming for reducing the deteriorating eff ects of salinity.

Aeroelastic stability analysis of a two-stage axially deploying telescopic wing with rigid-body motion effects

Sayed Hossein Moravej Barzani,Hossein Shahverdi Techno-Press 2023 Advances in aircraft and spacecraft science Vol.10 No.5

This paper presents the study of the effects of rigid-body motion simultaneously with the presence of the effects of temporal variation due to the existence of morphing speed on the aeroelastic stability of the two-stage telescopic wings, and hence this is the main novelty of this study. To this aim, Euler-Bernoulli beam theory is used to model the bending-torsional dynamics of the wing. The aerodynamic loads on the wing in an incompressible flow regime are determined by using Peters' unsteady aerodynamic model. The governing aeroelastic equations are discretized employing a finite element method based on the beam-rod model. The effects of rigid-body motion on the length-based stability of the wing are determined by checking the eigenvalues of system. The obtained results are compared with those available in the literature, and a good agreement is observed. Furthermore, the effects of different parameters of rigid-body such as the mass, radius of gyration, fuselage center of gravity distance from wing elastic axis on the aeroelastic stability are discussed. It is found that some parameters can cause unpredictable changes in the critical length and frequency. Also, paying attention to the fuselage parameters and how they affect stability is very important and will play a significant role in the design.

Enhancement of the anti-microbial activity of Mentha spicata essential oil on storage by glycerosomes

Sayed Latif Taheri,Jaleh Varshosaz 한국식품과학회 2023 Food Science and Biotechnology Vol.32 No.14

Mentha spicata essential oil (EO) is isolated from the aerial parts of Mentha spicata L. with pronounced antibacterial effects as food preservative in food industry. Nevertheless, its application in the clinical industry and food is significantly restricted by its poor water solubility and physicochemical instability. Glycerosomes of this EO were prepared to enhance its anti-microbial stability. The EO was encapsulated in the glycerosomes and characterized for its physical properties. The optimized EO-loaded glycerosomes displayed entrapment efficiency of 93.2 ± 7.5%, release efficiency of 75.4 ± 6.1%, the particle size of 276 nm, and zeta potential of − 30.4 mV. Scanning electron microscopy (SEM) image showed spherical morphology of the glycerosomes. EO release from optimized formulation of glycerosomes best fitted with a first-order kinetic model. Compared with free EO, EO-loaded glycerosomes showed better storage stability. The results indicated that the incorporation of EO in glycerosomes possessed sustained release properties and significantly enhanced antibacterial effects in storage.

The relationship between the development of musculoskeletal disorders, body mass index, and academic stress in Bahraini University students

( Sayed A Tantawy ),( Asma Abdul Rahman ),( Maryam Abdul Ameer ) 대한통증학회 2017 The Korean Journal of Pain Vol.30 No.2

Background: There are many mechanisms in which stress can lead to weight gain thus high a BMI. The endocrine and inflammatory pathway can directly increase abdominal adiposity. Another way in which stress leads to weight gain is through changes in health behaviors. The study aimed to investigate the prevalence of musculoskeletal disorders (MSDs) among healthy students of Ahlia University, and to determine the relationship between the development of MSDs and academic stressors and body mass index. Methods: Self-administered questionnaires were distributed to 94 students aged 18-26 years who were enrolled at various Ahlia University colleges and met other inclusion criteria. The students responded to the standardized Nordic musculoskeletal questionnaire and the modified College Student Stress Inventory regarding musculoskeletal symptoms and academic stressors. Height and weight measurements were also obtained to determine body mass index. Results: A total of 77.66% reported MSDs in one or more body part, with the prevalence being higher among women than among men. The 7-day prevalence of MSDs severe enough to interfere with activities of daily living was 60.64%, and 44.68% by female and male students, respectively. There was a significant relationship between academic stress and MSDs in the neck, shoulders, lower back, and hips, while the relationship between MSDs, and body mass index, academic stress, and grade point average was not significant.Conclusions: The prevalence of MSDs among Ahlia University students was found to be high. Apart from the positive correlation between academic stress and MSDs in certain body parts, other correlations were not significant. (Korean J Pain 2017; 30: 126-33)

The effect of microfinance on women’s empowerment : Evidence from Malaysia

Sayed Samer Ali AL-SHAMI,Muhammad M. RAZALI,Izaidin MAJID,Ahmed ROZELAN,Nurulizwa RASHID 이화여자대학교 아시아여성학센터 2016 Asian Journal of Women's Studies(AJWS) Vol.22 No.3

Microfinance is widely known as a financial development tool for those deprived of access to financial services, especially women. However, the literature provides conflicting evidence and shows that women’s empowerment may not, or may only be partially achieved through microcredit, especially in Muslim societies. This study seeks to scrutinize the effect of Amanah Ikhtiar Malaysia (AIM), a microcredit institution, on Malay Muslim women in an urban area. A quasi-experimental method was used to conduct a cross sectional survey of 500 old and new clients. Informal semi-structured interviews were conducted with 20 current clients who had received microcredit two years earlier. The findings show that AIM microcredit empowered the women and enhanced gender equality. It enabled women to access financial capital, form their micro- and smallbusinesses and obtain an income which helped them to contribute to household expenditure. Even though the effect of microcredit was partial, it provided them bargaining power for decision-making and controlling of resources and enhanced their self-esteem in their households and communities. Pembiayaan mikro secara meluasnya dikenali sebagai kaedah membangunkan mereka yang tidak diberi peluang akses perkhidmatan kewangan lain, khasnya di kalangan golongan wanita. Walau bagaimanapun, literatur kajian lampau telah mengemukakan bukti yang bercanggah di mana pembiayaan mikro kepada golongan wanita terutamanya mereka dalam masyarakat Islam mungkin tidak langsung atau mungkin sebahagiannya sahaja memberi kesan terhadap kejayaan mereka. Kajian ini bertujuan untuk meneliti kesan Amanah Ikhtiar Malaysia (AIM) iaitu sebuah institusi pembiayaan mikro, di kalangan wanita Melayu Islam di kawasan bandar. Satu kaedah kuasieksperimen telah digunakan untuk menjalankan kajian terhadap 500 pelanggan lama dan baru pembiayaan mikro. Temubual informal separa berstruktur telah dijalankan bersama 20 pelanggan yang sedang menerima pembiayaan mikro dalam tempoh dua tahun sebelumnya. Hasil kajian menunjukkan bahawa pembiayaan mikro AIM menjadikan wanita bertambah berjaya dan dapat menyumbang terhadap kesamarataan antara gender. Ia membolehkan mereka memperolehi modal, membentuk perniagaan mikro atau kecil dan seterusnya memperolehi pendapatan yang dapat membantu mereka untuk menyumbang kepada perbelanjaan isi rumah. Walaupun kesan pembiayaan mikro ini menyumbang kepada sebahagian sahaja peningkatan ini, namun ia dapat menyediakan mereka kuasa tawar-menawar untuk membuat keputusan, kawalan ke atas sumber dan meningkatkan keyakinan diri golongan ini.

Foundations forlowcostbuildings

Sayed Abde lSalam,Mahmoud Samir El-kady 한국CDE학회 2017 Journal of computational design and engineering Vol.4 No.2

Attaining aneconomicalandsafedesignofstructuresisregardedasaprerequisiteforthestructuralengineer.Themarketpricesofreinforcingsteels havedramaticallysoaredinrecentyearsinternationally.Therefore,thepurposeofthecurrentpaperisnotjustreducingtheratioofreinforcing steelinthefoundationsforskeletonstructures,butratherminimizingthisratiothroughchoosingthemosteffectivefootingshape(folded stripfootings).Foldedfootingshavebeenusedasanalternativetotheconventionalrectangularstripfootings.Theheightofthestudiedmodel isten floors. Twodifferentfoundationsystemsareusedintheanalysisnamely;rectangularstripfootings,andfoldedstripfootingsrespectively. Bothfootingshapeswillbedesignedascontinuousfootingswithgridshapeunderthebuilding.Comparisonbetweenthetwosystems isalsopresentedregardingtheconcretesectionsandreinforcementratiounderthesameappliedloads.The finite elementanalysissoftware ADINAisusedinmodelingandanalysisofthestructuralandgeotechnicalbehaviorofbothtypesoffootings,withemphasisontheeffect ofchangingthefootingshapeonthestressesinthefootingconcretebodyandtheunderlyingsoils.Researchresultspresentstheinternalstresses withinthefootingandsoildomains,aswellasthecontactpressuredistributionforareinforcedfoldedstripfootingrestingondifferentsoil types.Theinfluence offoldinginclinationangle,andsoiltypeontheresultsarealsostudied.Resultsshowedthatfoldedstripfootingsareefficient inreducingtheamountofneededreinforcements,andsuchefficiency inreducingtherequiredsteelreinforcementinthefootingsisdepending ontheappliedfootingloads,andtosomedegreeonthesoiltypeandproperties.Reductioninthereinforcementratiobetweentherectangular andfoldedfootingtypesisabout26%infavorofthefoldedstripfootings.Acomparativeeconomicalstudyshowsthatthetotalcostof thereinforcedconcretesectionforthefoldedstripfootingsislessthanthetraditionalonebyabout18%.Thisdifferenceincostofbothtypesof footingsismainlyduetotherelativelysmallerinsteelreinforcementrationeededforthefoldedtypeascomparedwiththerectangularones. So, thefoldedstripfootingismoreeconomicalthantherectangularstripfooting.

A systematic review of emotion recognition using cardio-based signals

Sayed Ismail Sharifah Noor Masidayu,Ab. Aziz Nor Azlina,Ibrahim Siti Zainab,Mohamad Mohd Saberi 한국통신학회 2024 ICT Express Vol.10 No.1

There is a growing demand for emotion recognition systems (ERS) to be adopted in everyday life from various fields, particularly automotive, education, and social security. Recently, the use of cardio-based physiological signals, electrocardiogram (ECG), and photoplethysmogram (PPG) in ERS has yielded promising results. Furthermore, the development of wearable devices equipped with cardio-based physiological sensors has significantly aided towards the adoption of ERS in daily life. This paper systematically reviews emotion recognition using cardio-based physiological signals, encompassing emotion models, emotion elicitation methods, and ERS development methods, emphasizing feature extraction, feature selection methods, feature dimension reduction methods, and classifiers. A summary and comparison of recent studies are presented to highlight existing studies’ gaps and suggest future research for better ERS especially using cardio-based signals.