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Cadmium Selenide Polymer Microfiber Saturable Absorber for Q-Switched Fiber Laser Applications

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Chinese Physics Letters 2017年第9期34卷 54-57页

作者： A.H.A.Rosol H.A.Rahman e.i.ismail N.irawati Z.Jusoh A.A.Latiff S.W.Harun Faculty of electrical engineering University Teknologi Mara Shah Alam 40450 Malaysia Department of electrical engineering University of Malaya Kuala Lumpur 50603 Malaysia Faculty of electrical engineering University Teknologi Mara (Terengganu) Dungun 23000 Malaysia Photonics Research Centre University of Malaya Kuala Lumpur 50603 Malaysia

We demonstrate the generation of a Q-switching pulse train in an erbium-doped fiber laser （eDFL） cavity using a newly developed cadmium selenide （CdSe） based saturable absorber （SA）. The SA is obtained by embedding CdSe nanomaterials into a polymethyl methacrylate （PMMA） microfiber. it is incorporated into an eDFL cavity to generate a Q-switched laser operating at 1533.6nm. The repetition rates of the produced pulse train are tunable within 37–64kHz as the pump power is varied from 34mW to 74mW. The corresponding pulse width reduces from 7.96μs to 4.84μs, and the maximum pulse energy of 1.16nJ is obtained at the pump power of 74mW.

关键词： Cadmium Selenide Polymer Microfiber Saturable Absorber for Q-Switched Fiber Laser Applications SA

Mode-locked fiber laser with a manganese-doped cadmium selenide saturable absorber

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Chinese Optics Letters 2017年第7期15卷 64-68页

作者： A.H.A.Rosol H.A.Rahman e.i.ismail Z.Jusoh A.A.Latiff S.W.Harun Faculty of electrical engineering University Teknologi Mara Department of electrical engineering Faculty of EngineeringUniversity of Malaya Faculty of electrical engineering University Teknologi Mara (Terengganu) Photonics Research Center University of Malaya

We demonstrate the generation of mode-locked pulses in an erbium-doped fiber laser（eDFL） by using a new manganese-doped cadmium selenide quantum-dots-based saturable absorber. The laser produces a soliton pulse train operating at 1561.1 nm with a repetition rate of 1 MHz, as the pump power is varied from 113 to 250 m *** the maximum pump power, we obtain the pulse duration of 459 ns with a signal-to-noise ratio of 50 dB.

关键词： locked absorber manganese cadmium repetition soliton varied oleic harmonics locking

Availability of seismic vulnerability index(K_g) in the assessment of building damage in Van, eastern Turkey

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earthquake engineering and engineering Vibration 2020年第1期19卷 189-204页

作者： ismail Akkaya Van Yüzüncü Yil University Engineering FacultyDepartment of Geophysical Engineering

The seismic vulnerability index(Kg) is a parameter that depends on the dynamic properties of soil. With this parameter, it is possible to evaluate the vulnerability of a point-based site under strong ground motion. Since it is related to the natural vibration period and amplification factor, the parameter can be calculated for both soil and structure. in this study, HVSR microtremor measurements are recorded at more than 200 points in the Van region to generate a seismic vulnerability index map. After generating the map, it is determined that the hazard potential and seismic vulnerability index is high at the sites close to Van Lake and at the densely populated city center. Damage information of the buildings investigated after the 2011 Van earthquakes(Mw = 7.1) are placed on the seismic vulnerability index map and it is realized that there may be a correlation between the damage and the seismic vulnerability index. There is a high correlation, approximately 80 percent, between the damage rate map based on the damaged building data and the K_g values. in addition, vulnerability indexes of buildings are calculated and the effect of local soil conditions and building properties on the damage levels are determined. From the results of this study and the site observations after the 2011 Van earthquakes, it is found that structural damage is not only structure-dependent but is also related to the dynamic behavior of soil layers and local soil conditions.

关键词： seismic vulnerability index building damage HVSR soil-structure interaction

Arctic sea-ice extent: No record minimum in 2023 or recent years

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Atmospheric and Oceanic Science Letters 2025年第1期18卷 52-55页

作者： Ola M.Johannessen Tor i.Olaussen Nansen Scientific Society BergenNorway Nansen environmental and Remote Sensing Center BergenNorway

Arctic sea-ice extent reaches its minimum each year in September. On 11 September 2023 the minimum was 4.969 million square kilometers(***^(2)). This was not a record low, which occurred in 2012, when the minimum was 4.175 ***^(2), 0.794 ***^(2) less than the minimum in 2023. However, the ice extent had decreased by 0.432 ***^(2) compared with 2022. Nevertheless, the summer melting in 2023 was remarkably less than expected when considering the strong heat waves in the atmosphere and ocean, with record temperatures set around the world. in general, there is a high correlation between the long-term decrease in sea-ice extent and the increasing CO_(2) in the atmosphere, where the increase of CO_(2) in recent decades explains about 80% of the decrease in sea ice in September, while the remainder is caused by natural variability.

关键词： Sea ice Arctic Minimum ice Climate

Coarse to Fine: The Role of Severe Plastic Deformation in Advancing Titanium-Based Medical implants - A Comprehensive Review

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Journal of Wuhan University of Technology(Materials Science) 2025年第1期40卷 295-306页

作者： Dragana R Mihajlović Bojan i Međo ivana Lj Cvijović-Alagić Veljko R Djokić Faculty of Technology and Metallurgy University of BelgradeKarnegijeva 411120 BelgradeSerbia Vinča institute of Nuclear Sci-ences-National institute of the Republic of Serbia University of Belgrade11001BeogradSerbia innovation Centre of the Faculty of Technology and Metallurgy Karnegijeva 411120 BelgradeSerbia

This paper describes severe plastic deformation(SPD)procedures,which are utilized to form an ultrafine-grained structure in metallic *** the SPD process,a solid material sample is subjected to very high loads without a significant change in sample *** the present work,the high-pressure torsion(HPT)process,as one of the SPD techniques,which achieves a high degree of deformation and ensures refinement of the microstructure,will be discussed in more *** that grain size control is accepted as a method to obtain materials with desired characteristics,an overview of the properties of ultrafine-grained titanium-based biomaterials to be used in medicine is ***,particular attention is dedicated to the influences of HPT process parameters,primarily hydrostatic pressure,and number of revolutions during torsion,on the grain size and physical and mechanical characteristics(modulus of elasticity,microhardness,and tensile properties),corrosion resistance,and biocompatibility of the titanium-based biomaterials.A review of the literature indicates that titanium-based materials obtained by the SPD process show improved mechanical and physical properties without losing biocompatibility and corrosion resistance,which suggests that these methods of obtaining implants are something that should be further developed in the future.

关键词： high-pressure torsion process ultrafine-grained titanium-based materials electrochemical anodization physical properties mechanical properties

Fuzzy rough sets in Sostak sense

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Applied Mathematics(A Journal of Chinese Universities) 2022年第4期37卷 563-582页

作者： ismail ibedou S.e.Abbas Department of Mathematics Faculty of ScienceBenha UniversityBenhaEgypt Department of Mathematics Faculty of ScienceSohag UniversitySohagEgypt

in this paper,we defined the fuzzy operator Φ_(λ) in a fuzzy ideal approximation space(X,R,i)associated with a fuzzy rough set λ in Sostak *** with Φ_(λ),there are fuzzy ideal interior and closure operators int_(Φ)^(λ) and cl_(Φ)^(λ),respectively.r-fuzzy separation axioms,r-fuzzy connectedness and r-fuzzy compactness in fuzzy ideal approximation spaces are defined and compared with the relative notions in r-fuzzy approximation *** are many differences when studying these notions related with a fuzzy ideal different from studying these notions in usual fuzzy approximation ***,using a fuzzy grill,we will get the same results given during the context.

关键词： fuzzy rough set fuzzy approximation space fuzzy ideal approximation space r-fuzzy separation axioms r-fuzzy connectedness r-fuzzy compactness

How to repair the Hill cipher

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Journal of Zhejiang University-Science A(Applied Physics & engineering) 2006年第12期7卷 2022-2030页

作者： ismail i.A. AMiN Mohammed DiAB Hossam Faculty of Computers and information Zagazig University Zagazig 44511 Egypt Computer Science Department Faculty of Science Menoufiya University Shebeen El-kom 32511 Egypt

The Hill cipher algorithm is one of the symmetric key algorithms that have several advantages in data encryption. However, a main drawback of this algorithm is that it encrypts identical plaintext blocks to identical ciphertext blocks and cannot encrypt images that contain large areas of a single color. Thus, it does not hide all features of the image which reveals patterns in the plaintext. Moreover, it can be easily broken with a known plaintext attack revealing weak security. This paper presents a variant of the Hill cipher that overcomes these disadvantages. The proposed technique adjusts the encryption key to form a dif- ferent key for each block encryption. Visually and computationally, experimental results demonstrate that the proposed variant yields higher security and significantly superior encryption quality compared to the original one.

关键词： Hill cipher image encryption Modified Hill cipher Quality of encryption

Study of micro-elongated thermoelastic medium loaded with a piezoelectric layer under the influence of gravity using the dual-phase-lag model

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international Journal of Mechanical System Dynamics 2023年第2期3卷 136-145页

作者： Mohamed i.A.Othman ebtesam e.M.eraki Mohamed F.ismail Department of Mathematics Faculty of ScienceZagazig UniversityZagazigEgypt Department of engineering Mathematics and Physics Higher Institute of EngineeringShorouk AcademyAl-Shorouk CityEgypt

This paper aims to examine the influence of gravity on a thermoelastic microelongated layer when a piezoelectric layer is above it,utilizing the theory of Lord–Shulman(L–S)and also the model of dual‐phase‐lag(DPL).A partial differential equation was transformed into an ordinary differential equation using the normal mode *** epoxy numerical computations are carried out,and the results are presented in graphical *** L–S theory and the model of DPL are compared in the presence and absence of gravity and it is found that gravity has quite a massive influence on all the physical quantities.

关键词： piezoelectrics normal mode analysis gravity micro‐elongated thermoelastic DPL model

Multisensory mechanisms of gait and balance in Parkinson’s disease:an integrative review

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Neural Regeneration Research 2025年第1期20卷 82-92页

作者： Stiven Roytman Rebecca Paalanen Giulia Carli Uros Marusic Prabesh Kanel Teus van Laar Nico i.Bohnen Department of Radiology University of MichiganAnn ArborMIUSA Department of Neurology University of MichiganAnn ArborMIUSA Morris K.Udall Center of excellence for Parkinson’s Disease Research University of MichiganAnn ArborMIUSA institute for Kinesiology Research Science and Research Centre KoperKoperSlovenia Department of Health Sciences Alma Mater Europaea–ECMMariborSlovenia Parkinson’s Foundation Research Center of excellence University of MichiganAnn ArborMIUSA Department of Neurology University of GroningenUniversity Medical Center GroningenGroningenThe Netherlands Neurology Service and GReCC VA Ann Arbor Healthcare SystemAnn ArborMIUSA

Understanding the neural underpinning of human gait and balance is one of the most pertinent challenges for 21st-century translational neuroscience due to the profound impact that falls and mobility disturbances have on our aging *** and gait control does not happen automatically,as previously believed,but rather requires continuous involvement of central nervous *** effectively exert control over the body,the brain must integrate multiple streams of sensory information,including visual,vestibular,and somatosensory *** mechanisms which underpin the integration of these multisensory signals are the principal topic of the present *** multisensory integration theories focus on how failure of cognitive processes thought to be involved in multisensory integration leads to falls in older *** emphasis,however,has been placed on specific contributions of individual sensory modalities to multisensory integration processes and cross-modal interactions that occur between the sensory modalities in relation to gait and *** the present work,we review the contributions of somatosensory,visual,and vestibular modalities,along with their multisensory intersections to gait and balance in older adults and patients with Parkinson’s *** also review evidence of vestibular contributions to multisensory temporal binding windows,previously shown to be highly pertinent to fall risk in older ***,we relate multisensory vestibular mechanisms to potential neural substrates,both at the level of neurobiology(concerning positron emission tomography imaging)and at the level of electrophysiology(concerning electroencephalography).We hope that this integrative review,drawing influence across multiple subdisciplines of neuroscience,paves the way for novel research directions and therapeutic neuromodulatory approaches,to improve the lives of older adults and patients with neurodegenerative diseases.

关键词： aging balance encephalography functional magnetic resonance imaging gait multisensory integration Parkinson’s disease positron emission tomography somatosensory vestibular visual