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A comparison of metabolic engineering strategies applied in Yarrowia lipolytica for ?-carotene production
No full textWith a better understanding of the health benefits of beta-carotene, the precursor of vitamin A, as well as its coloring property, the need for this carotenoid has increased in various sectors. In order to meet the increasing demand efficiently, cheaply, and sustainably, interest in heterologous beta-carotene production through metabolic engineering strategies has increased in recent years. In this context, although it is not a native producer of beta-carotene, Yarrowia lipolytica yeast stands out due to its metabolic, physiological, and genomic properties. Successful results have been obtained by using a series of engineering strategies, including biosynthesis pathway engineering, morphological engineering, and fermentation engineering strategies, in the production of heterologous beta-carotene from Y. lipolytica. However, these strategies have various strengths and weaknesses against each other, and there are also some points open to improvement. In this review, the engineering strategies that have been applied and have the potential to be applied for the production of beta-carotene from Y. lipolytica have been examined in depth, including their advantages and disadvantages, and compared with each other. Moreover, a future perspective has been presented to increase the potential of using Y. lipolytica yeast as a cell factory in beta-carotene production
AI-Based Investigation and Mitigation of Rain Effect on Channel Performance With Aid of a Novel 3D Slot Array Antenna Design for High Throughput Satellite System
No full textRain attenuation poses a significant challenge for high-throughput communication systems. In response, this paper introduces an artificial intelligence (AI) model designed for predicting and mitigating rain-induced impairments in high-throughput satellite (HTS) to land channels. The model is based on three AI algorithms developed using 3D antenna design to characterize, analyze, and mitigate rain-induced attenuation, optimizing channel quality specifically in the United Arab Emirates (UAE). The study evaluates various parameters, including rain-specific attenuation, effective slant path through rain, rain-induced attenuation, signal carrier-to-noise ratio, and symbol error rate, for five conventional modulation schemes: Quadrature Phase-Shift Keying (QPSK), 8-Phase Shift Keying (8-PSK), 16-Quadrature Amplitude Modulation (16-QAM), 32-QAM, and 64-QAM. Additionally, the paper introduces a new database detailing rain-induced attenuation in HTS channels in the UAE at different frequencies using measured rainfall intensities. The paper concludes by proposing a smart antenna design with a frequency diversity technique for fade mitigation. Results indicate that rain-induced attenuation varies significantly based on rainfall rate and frequency. Specifically, at 25 GHz and a rainfall rate of 100 mm/h, the rain-induced attenuation can reach as high as 15 dB, resulting in a significant decline in signal quality and link performance. The proposed AI model demonstrates the ability to intelligently predict rain-induced attenuation and channel quality for various rainfall rates and frequencies. This information can be valuable for optimizing satellite link design and operation, ultimately enhancing the reliability and quality of satellite communications. The proposed two-slot smart antenna design utilizes frequency diversity to effectively mitigate rain attenuation, contributing to the overall improvement of link reliability and quality.Universidad Carlos III de Madrid; European Union [801538]; King Saud University, Riyadh, Saudi Arabia [RSP2024R58]Dr. Mohammad Alibakhshikenari acknowledges the support from the CONEX-Plus programme funded by Universidad Carlos III de Madrid and the European Unions Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 801538. Additionally, the authors sincerely appreciate funding from Researchers Supporting Project number (RSP2024R58), King Saud University, Riyadh, Saudi Arabia
Light quarkonium hybrid mesons
No full textWe investigate the light quarkonium hybrid mesons of various spin parities in QCD. Considering different interpolating currents made of the valence light quarks and single gluon, we calculate the mass and current coupling of the strange and nonstrange members of light hybrid mesons by including into computations the nonperturbative quark and gluon condensates up to ten dimensions in order to increase the accuracy of the results. The obtained results may be useful for future experimental searches of these hypothetical states. They can also be used in the calculations of different parameters related to the decays/ interactions of light hybrid mesons to/with other states.TUBITAK [123F197]; Iran National Science Foundation (INSF) [4025036]The work of H. S. and B. B. was supported in part by the TUBITAK via the Grant No. 123F197. K. A. thanks Iran National Science Foundation (INSF) for the partial financial support provided under the elites Grant No. 4025036
The effect of printing parameters on hardness in the production of Poli lactic acid (PLA)-based samples with a 3D printer
No full textThe fused Deposited Modelling (FDM) technique, one of the additive manufacturing methods, has attracted much attention recently due to its high design flexibility and ability to create complex parts. While a wide variety of parts can be easily manufactured using 3D printers layer by layer according to traditional methods, the printing parameters significantly affect the mechanical properties of the products. This study aims to investigate the effect of printing parameters on the part's hardness. Nozzle diameter, layer height, raster angle, and nozzle temperature were chosen as the printing parameters to be investigated. Three levels were determined for each parameter, and the required high number of experiments was reduced by applying the Taguchi experimental design method. Polylactic acid (PLA) based samples were manufactured and tested according to ASTM standards. Hardness measurements were taken from 5 points on each sample using the Rockwell L method. The highest hardness value was measured as 45 HRL. Although the contribution of nozzle diameter to hardness is 85%, the effect of nozzle temperature is very low and uncertain. The hardness of the manufactured part is directly proportional to the layer thickness and inverse nozzle diameter. Productions made with high -diameter nozzles give better mechanical results and reduce production time. With the increase in the performance of 3D printers and the decrease in costs, the preference rate in manufacturing end -user products is increasing. This study will help to calculate the printing parameters with less uncertainty and variability in determining the surface hardness of the samples
Scalar exotic mesons bbcc
No full textProperties of doubly charged scalar tetraquarks bbcc are investigated in the framework of the Quantum Chromodynamic (QCD) sum rule method. We model them as diquark-antidiquark states X 1 and X 2 built of axial-vector and pseudoscalar diquarks, respectively. The masses and current couplings of these particles are computed using the QCD two-point sum rule method. Results m(1) = (12715 +/- 80) MeV and m(2) = (13370 +/- 95) MeV obtained for the masses of these particles are used to determine their kinematically allowed decay modes. The full width Gamma(1 )of the state X-1 is evaluated by taking into account its strong decays to mesons 2B(c)(-) , and 2B(c)(*-) . The processes X-2 -> 2B(c)(-) , 2B(c)*- and Bc-Bc-(2S) are employed to estimate Gamma(2). Predictions obtained for the full widths Gamma(1) = (63 +/- 12) MeV and Gamma(2) = (79 +/- 14) MeV of these structures and their masses may be utilized in experimental studies of fully heavy resonances.Iran National Science Foundation (INSF); [4025036]K Azizi is thankful to Iran National Science Foundation (INSF) for the financial support provided under the elites Grant No. 4025036
Heavy four-quark mesons bc(b)over-bar(c)over-bar : Scalar particle
No full textParameters of the heavy four-quark scalar meson T(bc ()b() over bar()c() over bar) with content bc (b) over bar(c) over bar are calculated by means of the sum rule method. This structure is considered as a diquark-antidiquark state built of scalar diquark and antidiquark components. The mass and current coupling of T-bc (b) over bar(c) over bar are evaluated in the context of the two-point sum rule approach. The full width of this tetraquark is estimated by taking into account two types of its possible strong decay channels. First class includes dissociation of T-bc (b) over bar(c) over bar to mesons eta(c)eta(b), Bc+Bc-, Bc*+Bc*- and B-c(+)(1(3)P(0))B-c(*-). Another type of processes are generated by annihilations (b) over barb ->(q) over barq of constituent b-quarks which produces the final-state charmed meson pairs D+D-, D-0(D) over bar (0), D*+D*-, and D*(0)(D) over bar*(0). Partial width all of these decays are found using the three-point sum rule method which is required to calculate strong couplings at corresponding meson-meson-tetraquark vertices. Predictions obtained for the mass m = (12697 +/- 90)MeV and width Gamma[T-bc (b) over bar(c) over bar]=(142.4 +/- 16.9)MeV of this state are compared with alternative results, and are useful for further experimental investigations of fully heavy resonances
Enhancing Power Generation in Triboelectric Nanogenerators via Integration of Graphene Nanoplatelets and Polyvinyl Alcohol
No full textTriboelectric nanogenerators (TENGs) provide promising power supply solutions by transforming mechanical energy into electrical energy. However, enhancing electrical performance of TENGs is essential for their widespread practical applications and commercialization. In this study, we fabricated TENGs in vertical contact-separation mode using a tribopositive material-polyvinyl alcohol (PVA) slime-which is biocompatible, flexible, and wearable, decorated with graphene nanoplatelets (GnPs), and paired with tribonegative silicone. We analyzed the correlation between the electrical performance of the TENGs and the inherent triboelectric properties of the constituent material, including the evaluation of surface roughness, the measurement of the contact potential difference (CPD), and the material's dielectric constant. The incorporation of GnPs increased the dielectric constant of the composite material and its electron-donating tendency, thus, increasing the contact potential difference. The GnPs concentration of 1 wt% was identified as the optimal value, resulting in a 42% increase in power density. The 1 wt% GnPs@PVA&Silicone TENG exhibited an open-circuit voltage of 718 V and a peak power density of 15.3 W/m2. This study sheds light on enhancing the energy harvesting efficiency of TENGs through the utilization of biocompatible tribopositive and tribonegative materials.TUBIdot;TAK-2219 International Postdoctoral Research Fellowship Program - Scientific and Technological Research Council of Turkiye [1059B192201266]Abdulkerim Okbaz was supported by the TUB & Idot;TAK-2219 International Postdoctoral Research Fellowship Program, funded by The Scientific and Technological Research Council of Turkiye (Grant No: 1059B192201266)
Investigation of the relationship between childhood traumas, psychological resilience, cognitive flexibility and emotion regulation skills in adults
No full textObjectives: This paper looked into the relation between childhood traumas, resilience, cognitive flexibility, and adult emotion regulation skills in adults. Methods: The sample, which is based on the relational screening model, includes 395 participants (female: 202, male: 193). Sociodemographic Information Form, Childhood Trauma Questionnaire, Connor-Davidson Resilience Scale, Cognitive Flexibility Scale and Cognitive Emotion Regulation Questionnaire were applied to the participants to obtain the research data. Data collection was carried out online (google forms) through convenient sampling. The t-test was used to compare the study's quantitative data, and Pearson Correlation analysis was utilized to test the relationship between the scales. Multiple Linear Regression analysis was used for predictive analysis and finally PROCESS was used for mediator role analysis. Results: The investigation's findings revealed that there is a statistically significant difference between the scores of the two groups compared. Findings showed that there is a moderately positive correlation between acceptance and CTQ scores, a weak positive correlation between acceptance and emotional abuse scores, a weak positive correlation with physical abuse scores, a weak positive correlation with physical neglect scores, a weak positive correlation with emotional neglect scores and weak positive correlation with sexual abuse scores. A weak and negative correlation exists between Putting into Perspective and the CTQ, an even weaker and negative correlation exists between Putting into Perspective and the Emotional Neglect and Sexual Abuse scores. Rumination scores have a weak and negative relationship with emotional abuse scores. Conclusions: In order to prevent them from serving as the foundation for difficulties with adult mental health, it is crucial to understand the relationship between traumatic childhood events and psychological resilience, cognitive flexibility, and cognitive emotion regulation techniques. In order to assist people, analyze their thoughts and feelings, be aware of negative coping mechanisms, rigid, inflexible cognitive styles, and negative thinking patterns, clinical psychology practices will benefit from research on these characteristics
SERMAYE YAPISININ FİRMA KARLILIĞI ÜZERİNDEKİ ETKİSİ: E7 VE G7 ÜLKELERİNİN KARŞILAŞTIRMALI ANALİZİ
No full textSermaye yapısı kısaca firmaların kaynak bileşimi olarak ifade edilmektedir. Kaynaklar genel olarak borç ve özsermaye olmak üzere ikiye ayrılır. Firma değeri ve sermaye maliyeti üzerinde borç ve özsermaye bileşiminde yapılan değişikliklerin etkilerinin incelenmesi, sermaye yapısı kararlarının temelini oluşturur. Ayrıca, sermaye yapısı kararları, firmanın karlılığını ve değerini maksimize edecek optimal sermaye yapısını araştırmak bakımından büyük önem taşır. Bu çalışmanın amacı 2016-2022 yılları arasında E7 ve G7 ülkelerinde ilgili endekslerde finans sektörü haricinde yer alan firmaların sermaye yapılarının karlılıkları üzerinde bir etkisi olup olmadığını araştırmaktır. Panel Veri Regresyon Analizi yönteminin uygulandığı çalışmada karlılık göstergesi olarak aktif, karlılığı ve özsermaye karlılığı oranları kullanılırken sermaye yapısı temsili oranları olarak toplam borç/toplam aktifler ve toplam borç/özsermaye seçilmiştir. Ayrıca aktif büyüklüğü, maddi duran varlık/toplam aktifler oranı, cari oran ve işletme riskliliği kontrol değişkenler olarak kullanılmıştır. Araştırma sonucunda genel olarak E7 ve G7 ülkeleri için ROA ve ROE değişkenleri ile sermaye yapısı oranları arasındaki ilişkinin anlamlı ve zıt yönlü olduğu gözlemlenmiştir
AN EFFICIENT METHOD FOR SOLVING FRACTIONAL INTEGRAL AND DIFFERENTIAL EQUATIONS OF BRATU TYPE
No full textIn this paper, the fractional integral and differential equations of Bratu type, which arise in many important physical phenomena, are investigated by an effective technique, Chebyshev Finite Difference Method with the help of fractional derivative in the concept of Caputo. The effect of the fractional derivative in the outcomes has great agreement with the nonlocality of the problem. The truncation and round off errors and convergence analyzes of the present method are also given. Numerical solutions of illustrative examples of the fractional integral and differential equations of Bratu type are given to highlight the validity and performance of the method. The results of the comparisons are very satisfied and show that the proposed technique is more effective and accurate than the other methods