Theory of coupled resonator optical waveguides exhibiting high-order exceptional points of degeneracy

We present an approach and a theoretical framework for generating high-order exceptional points of degeneracy (EPDs) in photonic structures based on periodic coupled resonator optical waveguides (CROWs). Such EPDs involve the coalescence of Floquet-Bloch eigenwaves in CROWs, without the presence of gain and loss, which contrasts with the parity-time symmetry required to develop exceptional points based on gain and loss balance. The EPDs arise here by introducing symmetry breaking in a conventional chain of coupled resonators through periodic coupling to an adjacent uniform optical waveguide, which leads to unique modal characteristics that cannot be realized in conventional CROWs. Such remarkable characteristics include high quality factors (Q factors) and strong field enhancement, even without any mirrors at the two ends of a cavity. We show for the first time the capability of CROWs to exhibit EPDs of various orders, including the degenerate band edge (DBE) and the stationary inflection point. The proposed CROW of finite length shows an enhanced quality factor when operating near the DBE, and the Q factor exhibits an unconventional scaling with the CROW's length. We develop the theory of EPDs in such unconventional CROW using coupled-wave equations, and we derive an analytical expression for the dispersion relation. The proposed unconventional CROW concepts have various potential applications including Q switching, nonlinear devices, lasers, and extremely sensitive sensors

Exceptional Points of Degeneracy Induced by Linear Time-Periodic Variation

We present a general theory of exceptional points of degeneracy (EPD) in periodically time-variant systems. We show that even a single resonator with a time-periodic component is able to develop EPDs, contrary to parity-time- (PT) symmetric systems that require two coupled resonators. An EPD is a special point in a system parameter space at which two or more eigenmodes coalesce in both their eigenvalues and eigenvectors into a single degenerate eigenmode. We demonstrate the conditions for EPDs to exist when they are directly induced by time-periodic variation of a system without loss and gain elements. We also show that a single resonator system with zero time-average loss-gain exhibits EPDs with purely real resonance frequencies, yet the resonator energy grows algebraically in time since energy is injected into the system from the time-variation mechanism. Although the introduced concept and formalism are general for any time-periodic system, here, we focus on the occurrence of EPDs in a single LC resonator with time-periodic modulation. These findings have significant importance in various electromagnetic and photonic systems and pave the way for many applications, such as sensors, amplifiers, and modulators. We show a potential application of this time-varying EPD as a highly sensitive sensor

KARAKTERISASI HASIL DAN PENENTUAN LAJU REAKSI FERMENTASI BONGGOLPISANG (Musa paradisiaca) MENJADI ETANOL DENGAN Saccharomyces cerevisiaeCHARACTERIZATION RESULTS AND DETERMINATION REACTION RATES OF BANANAWEEVIL (Musa paradisiaca) FERMENTATION INTO ETANOL WITH Saccharomyces cerevisiae

Abstrak. Telah dilakukan penelitian dengan tujuan untuk mengetahui karakteristik hasil dan laju reaksifermentasi bonggol pisang (Musa paradisiaca) menjadi Etanol dengan Saccharomyces cerevisiae.Pembuatan etanol bonggol pisang mengacu pada prinsip fermentasi dengan menggunakan Saccharomycescerevisiae. Fermentasi dengan Saccharomyces cerevisiae dilakukan pada variasi waktu 0, 24, 48, 72, 96,dan 120 jam. Etanol yang diperoleh selanjutnya dikarakterisasi kadar etanol berdasarkan Standart NasionalIndonesia SNI 7039:2008. Data karakteristik etanol dianalisis secara deskriptif, sedangkan penentuan lajureaksi hasil fermentasi pati bonggol pisang menjadi etanol dianalisis melalui metode diferensial.Didapatkan karakteristik kadar etanol pada waktu interaksi 0, 24, 48, 72, 96, dan 120 jam berturut-turut,2%, 4%; 5%; 9%; 12%; dan 11%. Sedangkan laju reaksi fermentasi pati bonggol pisang (Musa paradisiaca)menjadi etanol mengikuti persamaan laju reaksi orde satu, , dengan nilai konstanta laju (k)sebesar 0,0121.Kata Kunci: Bonggol pisang (Musa paradisiaca), Fermentasi bonggol pisang, Etanol.Abstract. Research has been conducted in order to determine the characteristics and the results of thereaction rate fermentation banana weevil (Musa paradisiaca) Into etanol with Saccharomyces cerevisiae.Making reference to the principle of etanol by using Saccharomyces cerevisiae. Fermentation withSaccharomyces cerevisiae has been done on the variation of time 0, 24, 48, 72, 96, and 120 hours. Etanolwere then characterized the value of etanol by the Indonesian National Standard 7039:2008. Etanolcharacteristic data were descriptively analyzed, while the determination of the reaction rate of fermentationinto etanol banana weevil analyzed through a diferential method. Characteristics of ethanol contentobtained interaction during 0, 24, 48, 72, 96, and 120 hours, respectively 2%, 4%; 5%; 9%; 12%; and 11%,The reaction rate of banana weevil (Musa paradisiaca) fermentation into etanol followed the first orderreaction rate equation, , with a rate of constant vale (k) is 0,0121.Keywords: Banana weevils (Musa paradisiaca), Banana weevil fermentation, Etanol

Lifestyle factors influencing bone health in young adult women in Saudi Arabia

Aim: To analyze risk factors leading to osteopenia and osteoporosis among young female students.Methods: Quantitative Ultrasonography measurements were performed in the calcaneal region of 101 young Saudi females. Dietary habits, exercising and sun exposure were assessed using questionnaires. The association between the different studied factors was assessed by Pearson test and multiple linear regression model.Results: Participants diagnosed with either osteopenia or osteoporosis (>33%.) showed significant higher soft drinks consumption, reduced exercise, limited intake of milk and dairy products, calcium and vitamin D supplementation compared to the healthy group. Multiple regression analysis showed that T-score and Z-score were negatively associated with soft drink intake and positively associated with exercising, milk and dairy products consumption, and calcium and vitamin D supplementation use (p <0.05)Conclusion: High soft drink intake, lack of exercising and limited calcium and vitamin D supplementation are the combined lifestyle factors leading to osteopenia and osteoporosis among young Saudi females. These findings might serve as a basis of nutrition education intervention to promote healthy bones among this population.Keywords: Lifestyle factors, osteoporosis, osteopenia, young women, Saudi Arab

Food determinants and motivation factors impact on consumer behavior in Lebanon

The current study looks at a variety of factors that affect eating patterns. This is about internal and external aspects that lead to a thorough assessment of consumer behavior, with an emphasis on driving forces and obstacles that significantly affect each consumer’s food preferences. The information is based on questionnaire research of traditional and fiber food consumption as well as specific consumer purchasing behaviors. The results of the questionnaire survey were analyzed using qualitative aspects analysis and other statistical methods (ANOVA, t-test). The study’s goal is to provide comprehensive strategies that encourage and support the intake of nutritious meals, especially in light of how different food motivations and knowledge factors influence Lebanese consumer behavior. Based on the findings, individual eating motivation and its impact on consumers’ behavior in Lebanon when making food purchase decisions were found. Sources of potential influences include information, the social environment, and environmental variables. Processes like social learning influence the interplay between these components as well as food choices and eating habits. As a result, future programs to encourage healthy eating habits might profit by putting more of an emphasis on learning principles and food preferences when programs are implemented.info:eu-repo/semantics/publishedVersio

Evaluation of Biological Control Potential for Different Trichoderma Strains Against Root-Knot Nematode Meloidogyne Javanica

Twenty strains of four Trichoderma species (Trichoderma harzianum, Trichoderma viride, Trichoderma koningii and Trichoderma asperellum) were evaluated for its potential to control the root-knot nematode Meloidogyne javanica. Culture filtrates from Trichoderma strains were tested in 24-well tissue culture plates for effects on Meloidogyne javanica. Chitwood egg hatch and mobility of hatched second-stage juveniles (J2) were evaluated, all the twenty Trichoderma strains showed the ability to colonize M. javanica separated eggs and second-stage juveniles (J2) in sterile in vitro assays. T. asperellum possess the strongest egg-parasitic ability and very effective against 2nd stage larvae of M. javanica. In this investigation, randomly amplified polymorphic DNA (RAPD) markers was used to estimate the genetic variations between four strains of Trichoderma asperellum (KC898190, KC898191, KC898192 and KC898193) which were previously isolated from the rhizospheres of different plants growing in Fayoum Governorate, Egypt as a new strain of T. asperellum in Egypt. RAPD assay using 6 random primers identified T. asperellum strains with 5 specific unique markers

Securing Messages by Using Coverless Steganography : A Survey

In the last few decades, with the digitalization of information, digital data transmitted overinsecure communication can be under attack, so driving steganography to the forefront for securecommunication. Steganography is a method of transmitting hidden data via a suitable multimedia carrier. The fundamental issue of stenographic system design is to strike a reasonable balance between security, robustness, greater bit embedding rate, and imperceptibility. To send hidden communications over the internet, sophisticated steganography techniques are required. However, the object used to hide secret messages within may be exposed by compression or any form of noise, causing the secret message to be extracted erroneously. Therefore, non-traditional basics for information security, such as coverless image steganography, are necessary. Coverless image steganography does not need the usage of a cover image to embed the hidden data; rather it use its own intrinsic properties to do so. This paper includes contributions to provide a comprehensive survey in this field, where the essential frameworks, preprocessing, feature extraction, creation of hash sequences, and its mapping links have all been discussed, as well as a steganography overview of its primary types, categorization, and applications. Existing methodologies are examined, as well as future development opportunities

Graphene — A Platform for Sensor and Biosensor Applications

Graphene, mother of all carbon materials, has opened up new era of exploration due to its unique properties. Graphene, one-atom thick, exhibits a unique chemical structure and outstanding electronic, optical, thermal, and mechanical properties that made it compelling for various engineering applications. Graphene and graphene-based materials are promising candidates for fabricating state-of-the-art nano-scale sensors and biosensors. They featured with good conductivity and large specific surface area thereby; graphene-based sensors/biosensors performed well with good accuracy, rapidness, high sensitivity and selectivity, low detection limits, and long-term stability. They are ideally used as gas sensors, electrochemical sensors for heavy metal ions, immunosensors and dihydronicotinamide dinucleotide NADH, DNA, catecholamine neurotransmitters, paracetamol, glucose, H2O2, hemoglobin, and myoglobin biosensors. This chapter reviews the applications of graphene in nanotechnology since it came to the field particularly in sensing and biosensing applications. It updates the reader with the scientific progress of the current use of graphene as sensors and biosensors. There is still much room for the scientific research and application development of graphene-based theory, materials, and devices. Despite the vast amount of research already conducted on graphene for various applications, the field is still growing and many questions remain to be answered