Stochastic modelling of intermittent scrape-off layer plasma fluctuations

Single-point measurements of fluctuations in the scrape-off layer of magnetized plasmas are generally found to be dominated by large-amplitude bursts which are associated with radial motion of blob-like structures. A stochastic model for these fluctuations is presented, with the plasma density given by a random sequence of bursts with a fixed wave form. Under very general conditions, this model predicts a parabolic relation between the skewness and kurtosis moments of the plasma fluctuations. In the case of exponentially distributed burst amplitudes and waiting times, the probability density function for the fluctuation amplitudes is shown to be a Gamma distribution with the scale parameter given by the average burst amplitude and the shape parameter given by the ratio of the burst duration and waiting times.Comment: 11 pages, 1 figur

Intention to donate via social network sites (SNSs): A comparison study between Malaysian and South Korean users

Purpose: The purpose of this paper is to explore the differences in the external factors influencing intention to donate via social network sites (SNSs), and the online donation knowledge and awareness effect on the willingness to donate via SNS in the future between Malaysian and South Korean users. Design/methodology/approach: In total, 288 samples’ data obtained from online survey using the snowball technique were analyzed through using cross-tabulation with χ2 tests and multiple regression analysis. Findings: The results show that there is no significant difference between those countries regarding the online donation knowledge and awareness. However, the online donation knowledge and awareness significantly affect the willingness to donate via SNSs for South Korean, but not for Malaysian. As for Malaysian, the results reveal that only SNS features factor does significantly influence the attitude toward online donations. As for South Korean, the charity project and internet technology features factor significantly influence the attitude toward online donations. The attitude toward online donations of both countries influences on their intention to donate via SNS. Research limitations/implications: The sample was gathered from certain regions in Malaysia and South Korea, and had slightly unbalanced characteristics (i.e. age), limiting the generalizability to the general population of both countries. Practical implications: The findings suggest that non-profit organizations should consider the culture context in planning their future SNS donation program and focus on how to deal with the internet issues (e.g. trust, security), SNS features and charity project. As for Malaysian, promoting the internet and online donation awareness should be the priority before engaging in SNS donation program. Originality/value: Whilst research on culture context in donation area is plentiful, the area of SNS donation remains underexplored. This paper offers an in-depth understanding of what influences SNS donation related to the identified culture context

Synthesis and Characterization of Some New Morpholine Derivatives

In this paper a new series of morpholine derivatives was prepared by reacting the morpholine with ethyl chloro acetate in the presence triethylamine as a catalyst in benzene gave morpholin-N-ethyl acetate(1) which reacted with hydrazine hydrate in ethanol, and gave morpholin-N-ethyl acetohydrazide (2) . Morpholin-N-aceto semithiocarbazide (3) were prepared by reacting compound(2) with ammonium thiocyanate , concentrated hydrochloric acid and ethanol as a solvent .Compound (3) reacted with sodium hydroxide and hydrochloric acid to give 5-(morpholin-N-methylene)-1H-1,2,4-triazole-3-thiol (4) .The new series of 1,2,4-triazol derivatives (5-8) was synthesized by reaction of compound(4) with formaldehyde , DMF as a solvent and different secondary amines. Preparation of new 1,2,4-triazoline derivatives (9) by reaction compound (4) with bromo acetic acid . Reaction of compound (9) with different aromatic aldehyde and dimethyl sulfoxide as a solvent obtained compounds (10-13)

Synthesis, Characterization and Study the Biological Activity of New Morpholine Derivative

A new series of morpholine derivative were prepared by reacting the morpholine with ethyl chloro acetate in the presence triethylamine as an catalyst and benzene as a solvent gave the ethyl morpholin-4-ylacetate reaction with hydrazine hydrate and ethanol as a solvent gave the 2-(morpholin-4-yl)acetohydrazide gave series of Schiff base were prepared by reacting 2-(morpholin-4- yl)acetohydrazide with different aromatic aldehydes and ketons . The new series of (3-9 )were synthesis by reaction of Schiff base (10-14) with chloroacetyl chloride, triethyl amine as an catalyst and 1,4dioxane as a solvent .The chemical structures of the synthesis compound were identified by spectral methods their [ IR ,1H-NMR and 13C-NMR ].The synthesised compounds were screened for antibacterial activity and antifungal activity promising by disc diffusion method by measuring the zone of inhibition and the results were compared to standard drugs ciprofloxacin

Staphylococcal infections among leukemic patients

Staphylococcus are cause hospital community acquired infection and they are an important cause of health –care associated infection.The Coagulase positive Staphylococcus are Staphylococcus aureus which can implicated in toxic shock syndrome. Methicillin and Vancomycin Staphylococcus aureus resistant (MRSA, VRSA) become major cause of hospital- acquired infection and community acquired infection.Coagulase negative staphylococcus emerged as major cause of infection in immunocompromised patients.The main objective of this study was to evaluate the distribution of Staphylococci among leukemic patients since it is well known that leukemic patients are prone to be infected easily due to their immunosuppressed status.This study was undertaken between oct. 2009 and Jun 2010 at Iraqi center of hematology and medical genetics. 140 clinical specimen(aspirated wound,superficial wound,urine, blood) have deen collected carefully from leukemic patients and subjected to well known established microbiological methods for diagnosis and identification of the isolates .All isolates were tested for their susceptibility to antimicrobials according to Kirby –Bauer technique.Out of 140 clinical specimen collected from leukemic patients, it was possible to obtain( 63) bacterial isolates form which(43) of Coagulase negative staphylococci (CONS) and (20) of Coagulase positive staphylococci. Out of 43(CONS) isolates has been found that S.epidermidis constitutes (28)the highest of all isolates. Antimicrobial susceptibility reveald that S.aureus is highly sensitive to Gentamycin (85%), Erythromycin (80%), while it is resistant to the drugs Cefotaxim (45%), Choramphenicol(40%),and Tetracycline(20%). S.epidermidis show highly sensitive to Erythromycin(100%),Vancomycin (100%), and Cefotaxim(70%) and highly resistant to the drugs Chloromphenicol(45%), Augmentin(45%),Gentamycin (10%), and Tetracycline(10%).It is concluded that S.epidemidis rankes the first( 28)among the isolates and S.aureus ranke the 2nd .All isolates were highly resistant to Chloramphenicol and highly sensitive to Erythromycine

Cancer care in Singapore

Singapore is a small country, but it is ideally and centrally located to conveniently serve not only its population but also patients from the surrounding regions. It’s economy is sufficiently strong to maintain highly sophisticated and expensive equipment to manage a high level of healthcare, including oncology services

Acinetobacter baumannii producing ESBLs and carbapenemases in the Intensive Care Units developing fosfomycin and colistin resistance

Acinetobacter baumannii is responsible for causing difficult-to-treat healthcare-associated infections globally, owing to its resistance to antibiotics. The intensive care unit (ICU) settings mediate spread of multidrug resistance (MDR) strains. This research aimed to evaluate non-susceptible colistin and fosfomycin A. baumannii, harboring extended-spectrum beta-lactamases (ESBLs) and carbapenemases in ICU setting. During the period of 2019-2021, this study obtained 200 A. baumanni isolates out of 1410 burns samples from an ICU setting. The antibiotic sensitivity, ESBLs and carbapenemase production were determined using clinical and laboratory standards institute (CLSI) 2020. The colistin (mcr-1 and mcr-2) and fosfomycin (fosA3) resistance genes was amplified. The highest resistance was to ceftazidime (98%), cefepime (86%), tetracycline (84%), levofloxacin (78%) and piperacillin-tazobactam (76%), while the highest sensitivity was to meropenem (63%) and tigecycline (62%). ESBL production was determined in 94% and carbapenemases were observed in 54% of A. baumannii. Four isolates (2%) were found to carry the mcr-1 gene, and three isolates (1.5%) were found to carry the mcr-2 gene. Moreover, the fosA3 was not detected in the isolates. This study showed that MDR A. baumannii was high in ICU settings. The spread of antibiotics considered the last line of defense against infections is a concern that necessitates surveillance and control measures

DESIGN AND OPTIMIZATION OF HIGH-SPEED MOTORIZED SPINDLE

In today's booming industrial development, with multi-product design and production cycle reduction, high-speed manufacturing technology has been widely adopted by manufacturers. With the development of science and technology, the high frequency spindle became more and more the place of ordinary mechanical spindle, and the numerical control machine was used very much. The engineering quality of the high-precision parts depends heavily on the dynamic performance of the entire operating system, which is determined by the interrelated dynamics of the mechanical structure of the machine tool and the cutting process. This performance is of great importance in advanced manufacturing processes and high precision. The most modern in the main circulation units of the machine tools is the focus on the automatic rotary units with high speed motors and high performance. In this letter, high-speed spindle analysis is designed and tested in specific load conditions. The spindle used in this letter is used in the milling machine. 3D modelling is designed in Pro / Engineer. Materials used in steel spindle. In this message, different spindle materials are analyzed. The aluminum alloy is replaced by 6061 and 7075 steel. When replacing steel with aluminium alloys, the weight of the spindle decreases. Structural and dynamic analyzes are performed using Ansys. A conditional analysis is also performed to determine frequencies

Frequency Dependent Rheology of Vesicular Rhyolite

Frequency dependent rheology of magmas may result from the presence of inclusions (bubbles, crystals) in the melt and/or from viscoelastic behavior of the melt itself. With the addition of deformable inclusions to a melt possessing viscoelastic properties one might expect changes in the relaxation spectrum of the shear stresses of the material (e.g., broadening of the relaxation spectrum) resulting from the viscously deformable geometry of the second phase. We have begun to investigate the effect of bubbles on the frequency dependent rheology of rhyolite melt. The present study deals with the rheology of bubble-free and vesicular rhyolite melts containing spherical voids of 10 and 30 vol %. We used a sinusoidal torsion deformation device. Vesicular rhyolite melts were generated by the melting (at 1 bar) of an Armenian obsidian (Dry Fountain, Erevan, Armenia) and Little Glass Mountain obsidian (California). The real and imaginary parts of shear viscosity and shear modulus have been determined in a frequency range of 0.005–10 Hz and temperature range of 600°–900°C. The relaxed shear viscosities of samples obtained at low frequencies and high temperatures compare well with data previously obtained by parallel plate viscometry. The relaxed shear viscosity of vesicular rhyolites decreases progressively with increasing bubble content. The relaxation spectrum for rhyolite melt without bubbles has an asymmetric form and fits an extended exponent relaxation. The presence of deformable bubbles results in an imaginary component of the shear modulus that becomes more symmetrical and extends into the low-frequency/high-temperature range. The internal friction Q −1 is unaffected in the high-frequency/low-temperature range by the presence of bubbles and depends on the bubble content in the high-temperature/low-frequency range. The present work, in combination with the previous study of Stein and Spera (1992), illustrates that magma viscosity can either increase or decrease with bubble content, depending upon the rate of style of strain during magmatic flow

Design Low Complexity SCMA Codebook Using Arnold’s Cat Map, Journal of Telecommunications and Information Technology, 2022, nr 4

In 5G wireless communications, sparse code multiple access (SCMA) – a multi-dimensional codebook based on a specific category of the non-orthogonal multiple access (NOMA) technique - enables many users to share non-orthogonal resource components with a low level of detection complexity. The multi-dimensional SCMA (MD-SCMA) codebook design presented in this study is based on the constellation rotation and interleaving method. Initially, a subset of the lattice Z 2 is used to form the mother constellation’s initial dimension. The first dimension is then rotated to produce other dimensions. Additionally, interleaving is employed for even dimensions to enhance fading channel performance. Arnold’s chaotic cat map is proposed as the interleaving method to reduce computational complexity. Performance of the SCMA codebook based on interleaving is evaluated by comparing it with selected codebooks for SCMA multiplexing. The metrics used for performance evaluation purposes include bit error rate (BER), peak to average power ratio (PAPR), and minimum Euclidean distance (MED), as well as complexity. The results demonstrate that the suggested codebook with chaotic interleaving offers performance that is equivalent to that of the conventional codebook based on interleaving. It is characterized by lower MED and higher BER compared to computer-generated and 16-star QAM codebook design approaches, but its complexity is lower than that of the conventional codebook based on interleaving