http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
3-아미노-1H-피라졸-4-카르복실산 에틸의 디아조화와 결합반응;피라졸로아진의 합성
Youssef, Ayman M.S.,Faty, Rasha A.M.,Youssef, Mohamed M. 대한화학회 2001 대한화학회지 Vol.45 No.5
피라졸로아진은 농업이나 의약품에서 매우 유용한 화합물등이다. 본 논문에서는 몇 가지 새로운 피라졸로아진의 합성을 보고하고자 한다. 표제 화합물인 3-아미노-1H-피라졸-4-카복실산 에틸을 다이아조화한 후 활성화된 메틸렌 화합물들과 반응시키고 고리화하여 피라졸로[5,1-c][1,2,4]트라이아진 유도체들을 합성하였다. 또한 표제 화합물을 $\alpha$-치환된 신남나이트릴과 반응시켜 피라졸로[1,5-a]피리미딘 유도체들을 합성하였다. 새로 합성된 화합물들의 구조는 화학적 방법과 분광학적 방법을 사용하여 확립하였다. Pyrazoloazines are extremely useful in agriculture and medicine. The main objective of this article is to synthesize some new pyrazoloazines. Ethyl 3-amino-1H-pyrazole-4-carboxylate undergoes diazotization, couples with activated methylene compounds and cyclizes to form pyrazolo[5,1-c][1,2,4]tri-azine derivatives. The title compound also reacts with $\alpha$-substituted cinnamonitriles to produce pyrazolo[1,5-a]pyrimidine derivatives. Structures of newly synthesized compounds are established via chemical and spectral methods.
Rochd Sara,Benhoummad Othmane,Salhi Salma,Lakhdar Youssef,Rochdi Youssef,Raji Abdelaziz,Oualhadj Hamza,Kamouni Youssef El,Zouhair Said 대한청각학회 2024 Journal of Audiology & Otology Vol.28 No.1
Lyme neuroborreliosis (LNB) is a rare but potentially serious manifestation of Lyme disease, caused by the spirochete <i>Borrelia burgdorferi</i>. Although LNB can affect various neurological systems, neurosensory hearing loss as the sole presentation is uncommon. We report a case of a 23-year-old woman who presented with a 2-month history of temporal headache, tinnitus, and instability, which was followed by sudden bilateral hearing loss without any other associated symptoms. Pure-tone audiometry revealed profound bilateral hearing loss. Serological testing for various pathogens was negative, except for <i>B. burgdorferi</i> IgM, which was confirmed using Western blot analysis. The patient received doxycycline treatment; unfortunately, no recovery of hearing was observed. This case report highlights the importance of considering LNB as a potential cause of neurosensory hearing loss, particularly in areas where Lyme disease is endemic, as well as the need for timely diagnosis and treatment to prevent potential complications.
Hazard identification and scenario selection of ship grounding accidents
Youssef, Samy Adly Mansour,Paik, Jeom Kee Elsevier 2018 Ocean engineering Vol.153 No.-
<P><B>Abstract</B></P> <P>The objectives of the present paper are to identify the hazard of ship grounding; where a ship runs on a rock with a forward speed, and to select a set of credible scenarios with a limited number that can still represent all possible situations of the accidents. For this purpose, the statistics of ship grounding accidents recorded by authorities for the period of 46 years during 1970–2016 are collated. An extensive analysis is undertaken to examine the statistical characteristics in association with random variables influencing the consequence of grounding. A total of six parameters, namely ship's forward speed, ship's trim angle, rock tip eccentricity, rock length, rock width and rock height are considered as random variables where the displacement or mass of the grounded ship is fixed. Each of the random variables is then formulated with a probability density function. A sampling technique is applied to the probabilistic selection of the grounding scenarios which are to be used for the consequence analysis within the framework of quantitative risk assessment. Important insights developed from the present study are discussed. Details of the analyses are documented.</P> <P><B>Highlights</B></P> <P> <UL> <LI> This article aims to identify the hazard of ship grounding to select a set of scenarios represent all possible situations. </LI> <LI> Statistics of ship grounding accidents recorded by authorities are collated. </LI> <LI> Extensive analyses are performed to examine the statistical characteristics with random variables of grounding. </LI> <LI> A sampling technique is applied to the probabilistic selection of the grounding scenarios. </LI> <LI> Selected credible scenarios are essential within the framework of quantitative grounding risk assessment and management. </LI> </UL> </P>
CFD Simulation Tool for Anode-Supported Flat-Tube Solid Oxide Fuel Cell
Youssef M. Elsayed.,Lim, Tak-Hyoung,Song, Rak-Hyun,Lee, Seung-Bok,Shin, Dong-Ryul The Korean Electrochemical Society 2006 한국전기화학회지 Vol.9 No.4
A two-dimensional numerical model to study the performance of anode-supported flat-tube solid oxide fuel cell (SOFC) far the cross section of the cell in the flow direction of the fuel and air flows is developed. In this model a mass and charge balance, Maxwell-Stefan equation as well as the momentum equation by using, Darcy's law are applied in differential form. The finite element method using FEMLAB commercial software is used for meshing, discritization and solving the system of coupled differential equations. The current density distribution and fuel consumption as well as water production are analyzed. Experimental data is used to verify a predicted voltage-current density and power density versus current density to judge on the model accuracy.
On the Maximal Output Admissible Set for a Class of Bilinear Discrete-time Systems
Youssef Benfatah,Amine El Bhih,Mostafa Rachik,Abdessamad Tridane 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.11
Given a discrete-time controlled bilinear systems with initial state x0 and output function yi, we investigate the maximal output set Θ(Ω) = {x0 ∈ Rn, yi ∈ Ω, ∀ i ≥ 0} where Ω is a given constraint set and is a subset of Rp. Using some stability hypothesis, we show that Θ(Ω) can be determined via a finite number of inequations. Also, we give an algorithmic process to generate the set Θ(Ω). To illustrate our theoretical approach, we present some examples and numerical simulations. Moreover, to demonstrate the effectiveness of our approach in real-life problems, we provide an application to the SI epidemic model and the SIR model.
A variant of Wilson's functional equation on semigroups
Youssef Aserrar,Abdellatif Chahbi,Elhoucien Elqorachi 대한수학회 2023 대한수학회논문집 Vol.38 No.4
Let $S$ be a semigroup. We determine the complex-valued solutions of the following functional equation \[f(xy)+\mu (y)f(\sigma (y)x) = 2f(x)g(y),\ x,y\in S,\] where $\sigma:S\rightarrow S$ is an automorphism, and $\mu :S\rightarrow \mathbb{C}$ is a multiplicative function such that $\mu (x\sigma (x))=1$ for all $x\in S$.
Effect of Electron Accepters on Step-up Photophobic Responses of Blephalisma japonicum
Youssef, Tareq,Angelini, Nicola,Gioffre, Domenico,Sgarbossa, Antonella,Lenci, Francesco Korean Society of Photoscience 2000 Journal of Photosciences Vol.7 No.1
The photosensory ciliates Blepharisma japonicum and Stentor coeruleus use the hypericin-derived pigments blepharismin and stentorin, respectively, as photoreceptor chromophores. Fluorescence quenching studies have shown that the first excited singlet state of hypericin and the purified chromophores blepharismin and stentorin can be deactivated by electron transfer to an acceptor molecule with a suitable reducing potential [1,2]. This paper reports the result of a series of photobehavioral experiments performed with the aim to ascertain if the same electron accepters which quench the photoreceptor pigment fluorescence in vitro may also compete with the native acceptor molecule in its natural physiological environment. Individual cell trajectories were examined before and after light stimulation, in the presence and in the absence of potential "in vivo" electron accepters, with a microvideo-recording apparatus. Our data, on Blepharisma cells, showed that as the negative reduction potential of the electron acceptor increases, a pronounced decrease in cell photoresponsiveness was detected. A dramatic effect on cell photoresponsiveness was noticed in the presence of 1,4-benzoquinone that has the lowest negative reduction potential. Such an effect on the percentage of photoreacting cells was moderate in the case of 1,4-naphthoquinone, with a relatively higher negative reduction potential. In the presence of benzophenone, which has the highest negative reduction potential, no significant effect on photoreacting cells was noticed. Our results can support the hypothesis that in the pigment granules such a light-induced charge transfer from excited blepharismin to a suitable electron acceptor triggers sensory transduction processes in B. japonicum.
SAMT: Shape-aware Multi-task Deep Convolutional Model for Crack Identification
Youssef Oumate(우마트 유셉),Seongmin Kim(김성민),JeanPierre Lomaliza(로말리자 장피에르),Joonhyeok Shin(신준혁),Jiyoung Lee(이지영),Seowoo Han(한서우) 대한전자공학회 2023 대한전자공학회 학술대회 Vol.2023 No.6
In this paper, we present a novel pipeline for crack classification using a multi-task model. Our model consists of two branches: a classification branch that distinguishes between crack and no crack images, and a segmentation branch that locates the crack region in the image. By combining these two tasks, our model can focus more on the crack itself and avoid being distracted by the surrounding regions. We also use the segmentation output to extract shape features from the crack region and combine them with the classification output to obtain a final crack score. This way, we can reduce the false positive rate significantly and achieve stateof-the-art results on various public datasets. We demonstrate that our multi-task model for crack identification is simple yet effective, achieving 87.29% and 90.14% Average Precision on SDNet2018 and Concrete Crack Images for Classification datasets, recursively.
Youssef S. Al Jabbari 대한치과보철학회 2011 The Journal of Advanced Prosthodontics Vol.3 No.4
Maxillary labial and buccal frena are considered as normal anatomic structures in the oral cavity. However, they may exist intraorally as a thick broad fibrous attachment and/or become located near the crest of the residual ridge, thus interfering with proper denture border extension resulting in inferior denture stability, retention and overall patient satisfaction. This case report highlights the importance of clinical examination and treatment planning which may mandate preprosthetic surgery prior to fabrication of a new conventional complete denture. Adequate patient satisfaction with conventional complete dentures can be significantly increased after frenectomy.