Kristalna struktura i optička svojstva sustava Bi-Sb-Te-Se

The quaternary systems of Bi-Sb-Te-Se were synthesized by direct fusion technique. Thin films of these compounds were prepared by thermal evaporation under vacuum of 10−4 Pa. The structural properties of these compounds in powder and thin film forms were investigated by X-ray diffraction. The optical constants (absorption coefficient and band gap) of the thin films were determined by measurements of IR absorbance in the region 2.5 – 10 µm. Analysis of the optical absorption spectra revealed the existence of two direct energy gaps.Sintetizirali smo sustave Bi-Sb-Te-Se sa četiri sastavnice izravnom metodom staljivanja. Tanke slojeve tih spojeva pripremali smo isparavanjem u vakuumu (na 10−4 Pa). Primjenom rendgenske difrakcije odredili smo strukturna svojstva praha i tankih slojeva tih spojeva. Optičke konstante tankih slojeva (koeficijent apsorpcije i procijep med–u vrpcama) odredili smo mjerenjem apsorpcije u području 2.5 – 10 µm. Analiza optičkih apsorpcijskih spektara pokazuje dva izravna procijepa

Kristalna struktura i optička svojstva sustava Bi-Sb-Te-Se

The quaternary systems of Bi-Sb-Te-Se were synthesized by direct fusion technique. Thin films of these compounds were prepared by thermal evaporation under vacuum of 10−4 Pa. The structural properties of these compounds in powder and thin film forms were investigated by X-ray diffraction. The optical constants (absorption coefficient and band gap) of the thin films were determined by measurements of IR absorbance in the region 2.5 – 10 µm. Analysis of the optical absorption spectra revealed the existence of two direct energy gaps.Sintetizirali smo sustave Bi-Sb-Te-Se sa četiri sastavnice izravnom metodom staljivanja. Tanke slojeve tih spojeva pripremali smo isparavanjem u vakuumu (na 10−4 Pa). Primjenom rendgenske difrakcije odredili smo strukturna svojstva praha i tankih slojeva tih spojeva. Optičke konstante tankih slojeva (koeficijent apsorpcije i procijep med–u vrpcama) odredili smo mjerenjem apsorpcije u području 2.5 – 10 µm. Analiza optičkih apsorpcijskih spektara pokazuje dva izravna procijepa

A proposal for testing Quantum Gravity in the lab

Attempts to formulate a quantum theory of gravitation are collectively known as {\it quantum gravity}. Various approaches to quantum gravity such as string theory and loop quantum gravity, as well as black hole physics and doubly special relativity theories predict a minimum measurable length, or a maximum observable momentum, and related modifications of the Heisenberg Uncertainty Principle to a so-called generalized uncertainty principle (GUP). We have proposed a GUP consistent with string theory, black hole physics and doubly special relativity theories and have showed that this modifies all quantum mechanical Hamiltonians. When applied to an elementary particle, it suggests that the space that confines it must be quantized, and in fact that all measurable lengths are quantized in units of a fundamental length (which can be the Planck length). On the one hand, this may signal the breakdown of the spacetime continuum picture near that scale, and on the other hand, it can predict an upper bound on the quantum gravity parameter in the GUP, from current observations. Furthermore, such fundamental discreteness of space may have observable consequences at length scales much larger than the Planck scale. Because this influences all the quantum Hamiltonians in an universal way, it predicts quantum gravity corrections to various quantum phenomena. Therefore, in the present work we compute these corrections to the Lamb shift, simple harmonic oscillator, Landau levels, and the tunneling current in a scanning tunneling microscope.Comment: v1: 10 pages, REVTeX 4, no figures; v2: minor typos corrected and a reference added. arXiv admin note: has substantial overlap with arXiv:0906.5396 , published in a different journa

Sustainable development in maritime education and training; trends, challenges and the way forward

As a run-up to the 2030 Sustainable Development Agenda, the International Maritime Organization (IMO), in 2013, adopted the concept of "a sustainable maritime transport system". The concept stresses the role of maritime education and training (MET) in realizing a sustainable maritime transport system. Maritime education and training institutions (METIs), therefore, have to integrate sustainable development (SD) into MET. This paper investigates the concept of an SD-based MET system vs. the business-as-usual STCW-based system. Trends within MET relating to SD are discussed while associated challenges are identified. Means of achieving an SD-based MET system are proposed while shedding light on a number of ongoing initiatives to integrate SD into MET. Finally, the possible contributions of MET institutions to the UN’s forthcoming "Decade of Ocean Science for Sustainable Development (2021-2030)" are considered

Extraction and characterization of Nanocellulose obtained from sugarcane bagasse as agro-waste

This study aimed to characterize nanocellulose extracted from sugarcane bagasse (SCB) by acid hydrolysis 60% (w/w) H2SO4 at 45 â—¦C. The effect of hydrolysis time (20, 30 and 40 min) on the structure and properties of the nanofibers was investigated. Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction (XRD) results indicated that the hemicellulose and lignin were removed extensively in the cellulose whiskers. The morphology and dimensions of the fibers and acid-released cellulose nanowhisker (CNW) were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results showed that SCB could be used as source to obtain cellulose whiskers and they had needle-like structures. Longer hydrolysis time produced a lower yield of nanofibers; whereas the degree of crystallinity increased from 38.22% to 65.37% with increasing hydrolysis time due to removal of amorphous cellulose

Retrospective application of SAFEMODE risk models to maritime investigation reports

The presentation elucidates the methodology employed to validate SAFEMODE Risk Models (RMs) using a robust dataset of 80 maritime accident investigation reports. Conducted between June 2021 and March 2022, the study involved 18 internal workshops with seven maritime partners. Initially, the risk models underwent group analysis sessions, which were followed by individual evaluations and cross-validation. Specifically focusing on the Collision in Congested Water Risk Model (CCW-RM), the study found that 80% of the identified 221 Base Events (BEs) were captured as contributing factors in incident reports. This validates the utility of SAFEMODE RMs to a certain extent. The presentation also delves into a detailed analysis of CCW-RM occurrences and other salient findings. Moreover, the risk models prove instrumental in prioritizing safety measures and yield actionable insights into Human Factors (HFs) and system reliability, thereby contributing to a fortified framework for maritime safety management

Polymorphism of growth hormone gene and its association with wool traits in Egyptian sheep breeds

Growth hormone (GH) gene has been described as a candidate gene for marker-assisted selection in different farm animals. The present study was designed to identify the polymorphism in GH gene and its association with variation of wool traits in Egyptian sheep breeds. Wool and blood samples were collected from 42 animals including two breeds (Barki and Rahmani) and one crossbred (Rahmani x Awase). Measurements of wool traits were analyzed and involved staple strength (Str), staple length (STL), fiber diameter (FD) and clean fleece yield (CFW). DNA was extracted from blood samples and a 365-bp fragment from exon V was amplified by polymerase chain reaction (PCR). Single strand conformation polymorphisim (SSCP) analysis showed two conformational patterns. The pattern I was recorded to be more frequent (83.3, 92.86 and 90%) than pattern II (16.7, 7.14 and 10%) in Barki, Rahmani and crossbred, respectively. The sequence analysis showed one single nucleotide polymorphism (C/T). The pattern I (allele T) has been found to affect CFW and FD than pattern II (allele C). Whereas, C allele was more pronounced for Str and STL. These traits are the most important parameters determining commercial values of wool that are preferred for clothing or carpets industry. The nucleotide sequences of C and T alleles were submitted to GenBank and have the accession numbers: KT250511 and KT250512, respectively. In conclusion, the present results provide evidence that there is a single nucleotide polymorphism within GH gene in Egyptian sheep breeds. This mutation was found to have some effects on wool traits. Therefore our data show interesting prospects in future selection programs for improving wool industry.Key words: Sheep, wool, growth hormone (GH) gene, polymorphism, single strand conformation polymorphism (SSCP)

A novel multivariate STeady-state index during general ANesthesia (STAN)

The assessment of the adequacy of general anesthesia for surgery, namely the nociception/anti-nociception balance, has received wide attention from the scientific community. Monitoring systems based on the frontal EEG/EMG, or autonomic state reactions (e.g. heart rate and blood pressure) have been developed aiming to objectively assess this balance. In this study a new multivariate indicator of patients' steady-state during anesthesia (STAN) is proposed, based on wavelet analysis of signals linked to noxious activation. A clinical protocol was designed to analyze precise noxious stimuli (laryngoscopy/intubation, tetanic, and incision), under three different analgesic doses; patients were randomized to receive either remifentanil 2.0, 3.0 or 4.0 ng/ml. ECG, PPG, BP, BIS, EMG and [Formula: see text] were continuously recorded. ECG, PPG and BP were processed to extract beat-to-beat information, and [Formula: see text] curve used to estimate the respiration rate. A combined steady-state index based on wavelet analysis of these variables, was applied and compared between the three study groups and stimuli (Wilcoxon signed ranks, Kruskal-Wallis and Mann-Whitney tests). Following institutional approval and signing the informed consent thirty four patients were enrolled in this study (3 excluded due to signal loss during data collection). The BIS index of the EEG, frontal EMG, heart rate, BP, and PPG wave amplitude changed in response to different noxious stimuli. Laryngoscopy/intubation was the stimulus with the more pronounced response [Formula: see text]. These variables were used in the construction of the combined index STAN; STAN responded adequately to noxious stimuli, with a more pronounced response to laryngoscopy/intubation (18.5-43.1 %, [Formula: see text]), and the attenuation provided by the analgesic, detecting steady-state periods in the different physiological signals analyzed (approximately 50 % of the total study time). A new multivariate approach for the assessment of the patient steady-state during general anesthesia was developed. The proposed wavelet based multivariate index responds adequately to different noxious stimuli, and attenuation provided by the analgesic in a dose-dependent manner for each stimulus analyzed in this study.The first author was supported by a scholarship from the Portuguese Foundation for Science and Technology (FCT SFRH/BD/35879/2007). The authors would also like to acknowledge the support of UISPA—System Integration and Process Automation Unit—Part of the LAETA (Associated Laboratory of Energy, Transports and Aeronautics) a I&D Unit of the Foundation for Science and Technology (FCT), Portugal. FCT support under project PEst-OE/EME/LA0022/2013.info:eu-repo/semantics/publishedVersio

A proposed protocol for GMP-BoK implementation gap analysis - case study at AASTMT

Purpose: Maritime Education and Training (MET) plays a crucial role in maintaining the safety and sustainability of the maritime industry. However, it remains behind the industry expectations to fulfill the gap regarding the required level of maritime capacities to safely control efficient new technology and keep them sustainable and effective during the industrial revolution era. The International Association of Maritime Universities (IAMU) developed the Global Maritime Professional Body of Knowledge (GMP-BoK) to address the current gap between the maritime industry expectations and the delivered Maritime Education and Training (MET) programs. Design/methodology/approach: This paper briefly introduces the GMP-BoK and proposes a protocol for a new analogous instrument to efficiently implement the GMP-BoK via a user-friendly method developed at the Arab Academy for Science, Technology and Maritime Transport (AASTMT). The developed analogous instrument helps maritime universities and institutes to digitalize and develop an integrated curriculum framework that is based on robust evaluation and data analysis to develop strategic plans to improve seafarer capabilities. Moreover, the paper suggests a protocol for mapping and analysis of maritime programs and courses, enabling educators to reliably perform gap analysis and identify repetitions within delivered courses and programs based on the GMP-BoK recommended practices. As a case study, the proposed protocol was validated utilizing the Maritime Engineering Technology Program (METP). Findings: The findings of this study revealed that the examined METP includes 30% repetition and focuses on the cognitive and psychomotor methods of education, with little focus on the affective technique