347 research outputs found
Experimental and numerical investigation of the reflection coefficient and the distributions of Wigner's reaction matrix for irregular graphs with absorption
We present the results of experimental and numerical study of the
distribution of the reflection coefficient P(R) and the distributions of the
imaginary P(v) and the real P(u) parts of the Wigner's reaction K matrix for
irregular fully connected hexagon networks (graphs) in the presence of strong
absorption. In the experiment we used microwave networks, which were built of
coaxial cables and attenuators connected by joints. In the numerical
calculations experimental networks were described by quantum fully connected
hexagon graphs. The presence of absorption introduced by attenuators was
modelled by optical potentials. The distribution of the reflection coefficient
P(R) and the distributions of the reaction K matrix were obtained from the
measurements and numerical calculations of the scattering matrix S of the
networks and graphs, respectively. We show that the experimental and numerical
results are in good agreement with the exact analytic ones obtained within the
framework of random matrix theory (RMT).Comment: 15 pages, 8 figure
PENGALAMAN REMAJA TENTANG PEMBERIAN VAKSINASI COVID -19 DI SMA TUNAS LUHUR KECAMATAN PAITON KABUPATEN PROBOLINGGO
Pengalaman dapat diartikan sebagai sesuatu yang pernah dialami, dijalani maupun dirasakan, baik sudah lama maupun yang baru saja terjadi. Imunisasi menggunakan vaksin adalah relatif aman tetapi bukan tanpa efek samping, karena sebagian orang dapat mengalami reaksi setelah imunisasi yang bersifat ringan sampai berat. Gejala KIPI disebabkan karena induksi vaksin seperti reaksi lokal (nyeri, bengkak didaerah suntikan) dan reaksi sistemik seperti demam sudah dapat perkirakan terlebih dahulu karena merupakan reaksi efek samping dan dilihat dari klinis biasanya ringan. Metode penelitian : Penelitian kualitatif dengan menggunakan metode purposive sampling dengan pendekatan fenomonologi ini bertujuan untuk mengeksplorasi pengalaman remaja tentang pemberian vaksin covid-19 di SMA Tunas Luhur Kecamatan Paiton. Sepuluh partisipan dipilih berdasarkan kriteria penelitian dan telah tersaturasi. Data dikumpulkan dengan wawancara mendalam dan observasi. Analisa Interpretative Phenomenological Analysis (IPA) di pergunakan dalam analisa data. Dua tema teridentifikasi dalam penelitian ini : (1) Respon Fisiologis setelah di vaksin (2) Respon psikologis setelah di vaksin. Respon fisiologis setelah di vaksin terdapat 3 sub tema : (1) Reaksi lokal : Nyeri, kemerahan, bengkak pada tempat suntikan (2) Reaksi Sistemik : Demam, Nyeri otot seluruh tubuh, nyeri sendi, badan lemes sakit kepala. (3) Reaksi Lain. Respon psikologis terdapat 3 subtema yaitu : (1) Gejala reaksi stress akut: peningkatan detak jantung, nafas cepat, mulut kering, berkeringat, kesemutan. (2) Nasovagal : penurunan laju jantung, masalah penglihatan singkop. (3) Gejala disosiatif neurologis : kelemahan otot. Hasil penelitian di dukung dengan fakta bahwa klien mengalami reaksi setelah di vaksin. Diperoleh kesimpulan bahwa terdapat pengalaman remaja tentang pemberian vaksin di SMA Tunas Luhur Paiton
Experimental simulation of quantum graphs by microwave networks
We present the results of experimental and theoretical study of irregular,
tetrahedral microwave networks consisting of coaxial cables (annular
waveguides) connected by T-joints. The spectra of the networks were measured in
the frequency range 0.0001-16 GHz in order to obtain their statistical
properties such as the integrated nearest neighbor spacing distribution and the
spectral rigidity. The comparison of our experimental and theoretical results
shows that microwave networks can simulate quantum graphs with time reversal
symmetry. In particular, we use the spectra of the microwave networks to study
the periodic orbits of the simulated quantum graphs. We also present
experimental study of directional microwave networks consisting of coaxial
cables and Faraday isolators for which the time reversal symmetry is broken. In
this case our experimental results indicate that spectral statistics of
directional microwave networks deviate from predictions of Gaussian orthogonal
ensembles (GOE) in random matrix theory approaching, especially for small
eigenfrequency spacing s, results for Gaussian unitary ensembles (GUE).
Experimental results are supported by the theoretical analysis of directional
graphs.Comment: 16 pages, 7 figures, to be published in Phys. Rev.
Photopolymer Resins with Biobased Methacrylates Based on Soybean Oil for Stereolithography
The accessibility of renewable materials that are both sustainable and competitive is essential to accommodate the rapid growth in consumption of 3D printing materials. We have developed biobased photopolymer resins based on modified soybean oil for application in commercial stereolithography printers. First, soybean oil methacrylates with various functionalities were successfully synthesized from epoxidized soybean oil as an alternative to commercially available soybean oil acrylate. A library of photoresins was created by mixing up to 80% of the biobased (meth)acrylate oligomers with biobased diluents and a photoinitiator. The resin composition was optimized to achieve a maximum biobased content and a low viscosity. The manufactured parts demonstrated complete layer fusion and accurate print quality. Stiffness and toughness can be tuned by altering the chemical composition or the number of functional groups per oligomer. These biobased materials can be employed to reduce the environmental impact of additive manufacturing while being competitive with current fossil-based resins from commercial manufacturers
Chaotic scattering with direct processes: A generalization of Poisson's kernel for non-unitary scattering matrices
The problem of chaotic scattering in presence of direct processes or prompt
responses is mapped via a transformation to the case of scattering in absence
of such processes for non-unitary scattering matrices, \tilde S. In the absence
of prompt responses, \tilde S is uniformly distributed according to its
invariant measure in the space of \tilde S matrices with zero average, < \tilde
S > =0. In the presence of direct processes, the distribution of \tilde S is
non-uniform and it is characterized by the average (\neq 0). In
contrast to the case of unitary matrices S, where the invariant measures of S
for chaotic scattering with and without direct processes are related through
the well known Poisson kernel, here we show that for non-unitary scattering
matrices the invariant measures are related by the Poisson kernel squared. Our
results are relevant to situations where flux conservation is not satisfied.
For example, transport experiments in chaotic systems, where gains or losses
are present, like microwave chaotic cavities or graphs, and acoustic or elastic
resonators.Comment: Added two appendices and references. Corrected typo
Acute effect of L-796568, a novel beta 3-adrenergic receptor agonist, on energy expenditure in obese men
Acute effect of L-796568, a novel beta 3-adrenergic receptor agonist, on energy expenditure in obese men. van Baak MA, Hul GB, Toubro S, Astrup A, Gottesdiener KM, DeSmet M, Saris WH. Nutrition and Toxicology Research Institute (NUTRIM), Department of Human Biology, Maastricht University, The Netherlands. [email protected] OBJECTIVE: Our objective was to investigate the thermogenic efficacy of single oral doses of the novel beta(3)-adrenergic receptor agonist L-796568 [(R )-N -[4-[2-[[2-hydroxy-2-(3-pyridinyl)ethyl]amino]ethyl]-phenyl]-4-[4-[4-(trifluoromethyl)phenyl]thiazol-2-yl]-benzenesulfonamide, dihydrochloride] in humans. METHODS: Twelve healthy overweight to obese men participated in this 2-center, 3-period, randomized, placebo-controlled, crossover trial. In each period subjects received 250 mg L-796568, 1000 mg L-796568, or placebo. Energy expenditure and respiratory quotient were determined by indirect calorimetry; blood samples were taken; and ear temperature, heart rate, and blood pressure were measured at baseline and during the 4-hour period after administration. RESULTS: Energy expenditure increased significantly after the 1000-mg dose (about 8%) and this was accompanied by an increase in plasma glycerol and free fatty acid concentrations. Systolic blood pressure also increased significantly. No changes in heart rate, diastolic blood pressure, ear temperature, plasma catecholamine, potassium, or leptin were found. CONCLUSIONS: Single-dose administration of 1000 mg of the novel beta(3)-adrenergic receptor agonist L-796568 increased lipolysis and energy expenditure in overweight men. This is the first study to show such an effect of beta(3)-adrenergic receptor agonists in humans without significant evidence for beta(2)-adrenergic receptor involvement
Classical wave experiments on chaotic scattering
We review recent research on the transport properties of classical waves
through chaotic systems with special emphasis on microwaves and sound waves.
Inasmuch as these experiments use antennas or transducers to couple waves into
or out of the systems, scattering theory has to be applied for a quantitative
interpretation of the measurements. Most experiments concentrate on tests of
predictions from random matrix theory and the random plane wave approximation.
In all studied examples a quantitative agreement between experiment and theory
is achieved. To this end it is necessary, however, to take absorption and
imperfect coupling into account, concepts that were ignored in most previous
theoretical investigations. Classical phase space signatures of scattering are
being examined in a small number of experiments.Comment: 33 pages, 13 figures; invited review for the Special Issue of J.
Phys. A: Math. Gen. on "Trends in Quantum Chaotic Scattering
A novel deletion mutation of the EXT2 gene in a large Chinese pedigree with hereditary multiple exostosis
Hereditary multiple exostoses (EXT) is an autosomal dominant disease characterized by the formation of cartilage-capped prominences (exostoses) that develop from the juxta-epiphyseal regions of the long bones. 3 genes are known to be involved in the formation of exostoses. Among them, EXT1 and EXT2, which encode enzymes that catalyse the biosynthesis of heparan sulfate, an important component of the extracellular matrix, are responsible for over 70% of the EXT cases. A large Chinese family with hereditary multiple exostoses has been analysed and the disease-causing mutation has been found. Blood samples were obtained from 69 family members, including 23 affected individuals. The EXT phenotype was shown to be linked to the EXT2 gene by using 2-point linkage analysis. After polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) analysis and DNA sequencing, a previously unreported deletion of a G in exon 3 of EXT2 gene was observed. This deletion co-segregated with the disease phenotype, suggesting that it is the disease-causing mutation in this family. Furthermore, in at least 4 members chondrosarcoma occurred after either an operation or injury of the exostosis and 3 of them died of the malignance in the family. Whether the operation or injury was responsible for the malignant transformation still needs further study. © 2001 Cancer Research Campaign http://www.bjcancer.co
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