Experimental Investigation of a Walk-in Refrigerator Performance Using R290 as a Retrofit for R22

A. R. El-Sayed,M. El Morsi,N. A. Mahmoud 대한설비공학회 2018 International Journal Of Air-Conditioning and Refr Vol.26 No.4

An experimental performance study is performed on a refrigeration system equipped with a scroll compressor and tested with R22 using an electronic expansion valve (EEV) as an expansion device and controlled by proportional-integral-derivative (PID) control method. The system is tested at −12∘C, −8∘C, −4∘C, 0∘C and 4∘C evaporator air temperature and 20∘C, 25∘C and 30∘C condenser inlet water temperature at 50 Hz compressor driving frequency and 50Hz evaporator fans driving frequency. R22 reached the set point at all temperatures except −12∘C evaporator temperature with 30∘C condenser temperature due to the severe increase in the compressor discharge temperature that could result in the lubricating oil burnout. Then, the system is retrofitted with a reciprocating compressor especially designed to be used with R290 and tested with R290 at the same evaporator and condenser temperatures using EEV as an expansion device. R290 reached all set points at all evaporator and condenser temperatures. Also, R290 was able to reach all evaporator temperatures at higher condenser temperatures, 35∘C and 40∘C, and this will be discussed in future work. The results show that using R290, the pulldown time decreases by 30.3–71.4%, the ON time ratio decreases by 1–23.6%, the compressor discharge temperature decreases by 46.6–81∘C, the refrigerant mass flow rate decreases by 28.8–50.4%, VRC decreases by 15.2–32.5%, the compressor power consumption decreases by 34.4–44.3% and coefficient of performance (COP) increases by 35–115.5%.

Experimental Performance Analysis of R1234yf in an Air-Conditioning System as Substitute of R134a

Medany M. M.,El Morsi M.,El-Sayed A.R. 대한설비공학회 2021 International Journal Of Air-Conditioning and Refr Vol.29 No.4

In this work, R1234yf is tested in an air-conditioning system as a proposed alternative to R134a. The system is tested at 30, 35, 40, 45 and 50[Formula: see text]Hz evaporator fan frequency to cool the air entering into the evaporator section at a fixed temperature of 35 ∘ C. The system is charged with 600, 700, 800, 1000 and 1200[Formula: see text]g of each refrigerant. The charge mass of 800 grams gives the best performance for both refrigerants. Also, R1234yf has higher COP, exergetic efficiency, second law efficiency, and lower compressor power consumption. Both refrigerants operate at a moderate range of compressor discharge temperature of 85 ∘ C.

On Fuzzifying Nearly Compact Spaces

A.M. Zahran,O.R. Sayed,M. Azab Abd-Allah,A.K. Mousa 한국지능시스템학회 2010 INTERNATIONAL JOURNAL of FUZZY LOGIC and INTELLIGE Vol.10 No.4

This paper considers fuzzifying topologies, a special case of I-fuzzy topologies (bifuzzy topologies) introduced by Ying [16, (I)]. It investigates topological notions defined by means of regular open sets when these are planted into the framework of Ying's fuzzifying topological spaces (in Łukasiewwicz fuzzy logic). The concept of fuzzifying nearly compact spaces is introduced and some of its properties are obtained. We use the finite intersection property to give a characterization of fuzzifying nearly compact spaces. Furthermore, we study the image of fuzzifying nearly compact spaces under fuzzifying completely continuous functions, fuzzifying almost continuity and fuzzifying R-map.

On Fuzzifying Nearly Compact Spaces

Zahran, A.M.,Sayed, O.R.,Abd-Allah, M. Azab,Mousa, A.K. Korean Institute of Intelligent Systems 2010 INTERNATIONAL JOURNAL of FUZZY LOGIC and INTELLIGE Vol.10 No.4

This paper considers fuzzifying topologies, a special case of I-fuzzy topologies (bifuzzy topologies) introduced by Ying [16, (I)]. It investigates topological notions defined by means of regular open sets when these are planted into the frame-work of Ying's fuzzifying topological spaces (in ${\L}$ukasiewwicz fuzzy logic). The concept of fuzzifying nearly compact spaces is introduced and some of its properties are obtained. We use the finite intersection property to give a characterization of fuzzifying nearly compact spaces. Furthermore, we study the image of fuzzifying nearly compact spaces under fuzzifying completely continuous functions, fuzzifying almost continuity and fuzzifying R-map.

EFFECT OF DROWSINESS ON DRIVING PERFORMANCE VARIABLES OF COMMERCIAL VEHICLE DRIVERS

A. MORTAZAVI,A. ESKANDARIAN,R. A. SAYED 한국자동차공학회 2009 International journal of automotive technology Vol.10 No.3

Driver drowsiness is a major safety concern, especially among commercial vehicle drivers, and is responsible for thousands of accidents and numerous fatalities every year. The design of a drowsiness detection system is based on identifying suitable driver-related and/or vehicle-related variables that are correlated to the driver’s level of drowsiness. Among different candidates, vehicle control variables seem to be more promising since they are unobtrusive, easy to implement, and cost effective. This paper focuses on in-depth analysis of different driver-vehicle control variables, e.g., steering angle, lane keeping, etc. that are correlated with the level of drowsiness. The goal is to find relationships and to characterize the effect of a driver’s drowsiness on measurable vehicle or driving variables and set up a framework for developing a drowsiness detection system. Several commercial drivers were tested in a simulated environment and different variables were recorded. This study shows that drowsiness has a major impact on lane keeping and steering control behavior. The correlation of the number and type of accidents with the level of drowsiness was also examined. Significant patterns in lateral position variations and steering corrections were observed, and two phases of drowsiness-related degradation in steering control were identified. The two steering degradation phases examined are suitable features for use in drowsiness detection systems. Driver drowsiness is a major safety concern, especially among commercial vehicle drivers, and is responsible for thousands of accidents and numerous fatalities every year. The design of a drowsiness detection system is based on identifying suitable driver-related and/or vehicle-related variables that are correlated to the driver’s level of drowsiness. Among different candidates, vehicle control variables seem to be more promising since they are unobtrusive, easy to implement, and cost effective. This paper focuses on in-depth analysis of different driver-vehicle control variables, e.g., steering angle, lane keeping, etc. that are correlated with the level of drowsiness. The goal is to find relationships and to characterize the effect of a driver’s drowsiness on measurable vehicle or driving variables and set up a framework for developing a drowsiness detection system. Several commercial drivers were tested in a simulated environment and different variables were recorded. This study shows that drowsiness has a major impact on lane keeping and steering control behavior. The correlation of the number and type of accidents with the level of drowsiness was also examined. Significant patterns in lateral position variations and steering corrections were observed, and two phases of drowsiness-related degradation in steering control were identified. The two steering degradation phases examined are suitable features for use in drowsiness detection systems.

Pathogenesis and Bone Resorption in Acquired Cholesteatoma: Current Knowledge and Future Prospectives

Mahmood A. Hamed,Seiichi Nakata,Ramadan H. Sayed,Hiromi Ueda,Badawy S. Badawy,Yoichi Nishimura,Takuro Kojima,Noboru Iwata,Ahmed R. Ahmed,Khalid Dahy,Naoki Kondo,Kenji Suzuki 대한이비인후과학회 2016 Clinical and Experimental Otorhinolaryngology Vol.9 No.4

Cholesteatoma is a cystic non tumorous lesion of the temporal bone that has the ability to destroy nearby structures by its power to cause bone resorption and as a result, fatal complications prevail. We aimed to conduct a comprehensive review for pathogenesis of acquired cholesteatoma, bone resorption mechanisms, and offer a future vision of this serious disease. We have reviewed different theories for pathogenesis of acquired cholesteatoma including the most relevant and updated ones with special emphasis on the mechanisms of bone resorption through Medline/PubMed research using the keywords ‘aetiopathogenesis, bone resorption, acquired cholesteatoma, temporal bone, and cytokines.’ In order to strengthen our study, we searched the reference lists of identified reviews. Cholesteatoma is a subject of debate among otolaryngologists since it was prescribed firstly. Over many decades, several theories were postulated for aetiopathogenesis of cholesteatoma with a tendency to follow more than one theory to explain the proper nature of that disease. Until now, the mechanism of bone resorption has yet to be more clarified. In the last century, a leap has occurred in the field of biomolecular cholesteatoma research which improved our knowledge about its pathophysiology and bone destructive mechanism. However, surgery is still the only available treatment. We conclude that discovery of new therapeutic choices for cholesteatoma other than surgery by the use of anti-growth, anti-proliferative, apoptotic agents as well as medications that antagonize osteoclastogenesis should be the main concern in the future clinical and experimental research work. Also, searching for predictors of the aggressiveness of cholesteatoma can affect the timing of intervention and prevent occurrence of complications.

Amplitude analysis ofe+e−→ϒ(nS)π+π−ats=10.866 GeV

Garmash, A.,Bondar, A.,Kuzmin, A.,Abdesselam, A.,Adachi, I.,Aihara, H.,Al Said, S.,Asner, D. M.,Aulchenko, V.,Aushev, T.,Ayad, R.,Bakich, A. M.,Bala, A.,Bhardwaj, V.,Bobrov, A.,Bonvicini, G.,Bozek, A. American Physical Society 2015 PHYSICAL REVIEW D - Vol.91 No.7

Measurement of the decayB→Dℓνℓin fully reconstructed events and determination of the Cabibbo-Kobayashi-Maskawa matrix element|Vcb|

Glattauer, R.,Schwanda, C.,Abdesselam, A.,Adachi, I.,Adamczyk, K.,Aihara, H.,Al Said, S.,Asner, D. M.,Aushev, T.,Ayad, R.,Aziz, T.,Badhrees, I.,Bakich, A. M.,Bansal, V.,Barberio, E.,Bhuyan, B.,Biswal, American Physical Society 2016 Physical Review D Vol.93 No.3

<P>We present a determination of the magnitude of the Cabibbo-Kobayashi-Maskawa matrix element vertical bar V-cb vertical bar using the decay B -> Dl nu(l) (l = e,mu) based on 711 fb(-1) of e(+)e(-) -> Upsilon(4S) data recorded by the Belle detector and containing 772 x 10(6) B (B) over bar pairs. One B meson in the event is fully reconstructed in a hadronic decay mode, while the other, on the signal side, is partially reconstructed from a charged lepton and either a D+ or D-0 meson in a total of 23 hadronic decay modes. The isospin-averaged branching fraction of the decay B -> Dl nu(l) is found to be B(B-0 -> D(-)l(vertical bar)nu(l)) = (2.31 +/- 0.03(stat) +/- 0.11(syst))%. Analyzing the differential decay rate as a function of the hadronic recoil with the parametrization of Caprini, Lellouch, and Neubert and using the form-factor prediction G(1) = 1.0541 +/- 0.0083 calculated by FNAL/MILC, we obtain eta(EW)vertical bar V-cb vertical bar = (40.12 +/- 1.34) x 10(-3), where eta(EW) is the electroweak correction factor. Alternatively, assuming the model-independent form-factor parametrization of Boyd, Grinstein, and Lebed and using lattice QCD data from the FNAL/MILC and HPQCD collaborations, we find eta(EW)vertical bar V-cb vertical bar = (41.10 +/- 1.14) x 10(-3).</P>

Life Span Extension of Caenorhabditis elegans by Novel Pyridoperimidine Derivative

Ahmed A. R. Sayed,Kamal M. El-Shaieb,Aboul-Fetouh E. Mourad 대한약학회 2012 Archives of Pharmacal Research Vol.35 No.1

Zwitterions formed from the addition of triphenylphosphine to dialky acetylene-dicarboxylates attack the nucleus of both 1H-perimidine (1) and 1H-benzo[d]imidazole (9) to form novel pyrido[1,2,3-cd]perimidine and imidazo[4,5,1-ij]quinoline derivatives in moderate yields (64-72%). The biological activity of the products has been studied. Compound 3a was found to extend life span of wild type Caenorhabditis elegans under standard laboratory conditions. Both heat stress and induced chemical stress resistance of wild type C. elegans were improved in a reverse dose-dependent manner due to 3a treatment. In addition, treatment of worms with compound 3a significantly attenuated the formation of advanced glycation end products in a reverse dose-dependent manner.

Search for a dark vector gauge boson decaying toπ+π−usingη→π+π−γdecays

Won, E.,Adachi, I.,Aihara, H.,Al Said, S.,Asner, D. M.,Aushev, T.,Ayad, R.,Badhrees, I.,Bakich, A. M.,Bansal, V.,Barberio, E.,Behera, P.,Bhuyan, B.,Biswal, J.,Bobrov, A.,Bozek, A.,Brač,ko, M.,&#x American Physical Society 2016 Physical Review D Vol.94 No.9

<P>We report a search for a dark vector gauge boson U' that couples to quarks in the decay chain D*(+) -> D-0 pi(+), D-0 -> K-S(0) eta, eta -> U'gamma, U' -> pi(+)pi- No signal is found and we set a mass-dependent limit on the baryonic fine structure constant of 10(-3)-10(-2) in the U' mass range of 290 to 520 MeV/c(2). This analysis is based on a data sample of 976 fb(-1) collected by the Belle experiment at the KEKB asymmetric-energy e(+)e(-) collider.</P>