548 research outputs found
Compact Triple-Mode Microwave Dielectric Resonator Filters
This paper presents a novel and compact triple-mode dielectric resonator (DR) band- pass filter (BPF) based on a single waveguide cavity. A triple-mode resonator can be achieved by pairing the degenerate EH₁₁ modes with a TM01δ mode. The DR structure is composed of two slitted pieces of dielectric pucks that are placed in the middle of a cylindrical metallic cavity. The resonator offers a size reduction ratio of about 15.6% compared with equivalent air-filled coaxial filters. A coaxial probe is used to excite the degenerate EH₁₁ modes while the TM01 mode is excited using a vertical hole etched in the ceramic pucks. Finally, a 3rd order generalised Chebyshev BPF is simulated using HFSS software. The filter has finite transmission zeros(TZ) on the high or low side of the passband
Design and Characterisation of HE11 Dual-Mode Dielectric-Loaded Filter for Cellular Base Station Applications
This paper presents a HE11 dual-mode dielectric-loaded bandpass filter for cellular base station applications. The filter consists of a ceramic puck that is placed centrally on the base of a metallic housing. The resonator offers a size reduction ratio of approximately 7:1 compared with equivalent air-filled coaxial filters. The filter is designed at a resonant frequency of 2.05 GHz and bandwidth of 50 MHz. The spurious-free window (SFW) was 500 MHz from the fundamental frequency. A fourth order dual-mode bandpass filter is designed, fabricated, and tested to validate the proposed approach. A good agreement between the measurement and simulation results is demonstrated
Lattice dynamical signature of charge density wave formation in underdoped YBa2Cu3O6+x
We report a detailed Raman scattering study of the lattice dynamics in
detwinned single crystals of the underdoped high temperature superconductor
YBa2Cu3O6+x (x=0.75, 0.6, 0.55 and 0.45). Whereas at room temperature the
phonon spectra of these compounds are similar to that of optimally doped
YBa2Cu3O6.99, additional Raman-active modes appear upon cooling below ~170-200
K in underdoped crystals. The temperature dependence of these new features
indicates that they are associated with the incommensurate charge density wave
state recently discovered using synchrotron x-ray scattering techniques on the
same single crystals. Raman scattering has thus the potential to explore the
evolution of this state under extreme conditions.Comment: 12 pages, 11 figure
Laser ablation loading of a surface-electrode ion trap
We demonstrate loading by laser ablation of Sr ions into a
mm-scale surface-electrode ion trap. The laser used for ablation is a pulsed,
frequency-tripled Nd:YAG with pulse energies of 1-10 mJ and durations of 3-5
ns. An additional laser is not required to photoionize the ablated material.
The efficiency and lifetime of several candidate materials for the laser
ablation target are characterized by measuring the trapped ion fluorescence
signal for a number of consecutive loads. Additionally, laser ablation is used
to load traps with a trap depth (40 meV) below where electron impact ionization
loading is typically successful ( 500 meV).Comment: 4 pages, 4 figure
Uticaj dodatka Saccharomyces cerevisiae u ishrani na zdravlje i proizvodnju krava tokom perioda tranzicije i početka laktacije
Data concerning the effect of probiotics supplementation on many parameters concurrently at the same cows are lacking. Therefore, the objective of this experiment was to investigate the effects of Saccharomyces cerevisiae feeding on rumen, blood and milk parameters together in high- producing dairy cattle during the transition and early lactation period. Sixteen clinically healthy Holstein cows were divided into 2 groups: a control group of 6 cows and a probiotics-fed group of 10 cows. Rumen fluid and blood samples were collected 21 days before the expected calving as well as 7, 15, 30, 45 and 60 days- in-milk (DIM). Milk yield for each animal was recorded every 2 weeks. Individual milk samples were collected 15, 30, 45 and 60 DIM. Ruminal pH and rumen ammonia nitrogen were significantly lower, whereas total volatile fatty acids were significantly higher in yeast-fed animals compared with controls throughout the study. Serum concentrations of total proteins and globulins were higher, while albumins were lower in the yeast-treated group. Serum glucose levels were significantly higher in yeast-supplemented animals. Serum triglycerides, high density lipoproteins, and low density lipoproteins concentrations were lower, with cholesterol being significantly lower in the treated group. Milk production and milk fat percentage were higher, whereas milk protein percentage and somatic cell count were decreased in yeast-supplemented cows throughout the study. These results suggest that supplementation of S. cerevisiae to dairy cows rations during transition and early lactation period improve their health and milk production parameters.Podaci koji bi se odnosili na uticaj suplementacije probiotika na više parametara istovremeno na istim grlima nedostaju u literaturi. Stoga je cilj ovog eksperimenta bio da se ispita uticaj Saccharomices cerevisiae u obroku/hrani na parametre rumena, krvi i mleka zajedno u visoko-proizvodnim mlečnim govedima tokom tranzicije i početkom laktacije. Šesnaest klinički zdravih holštajn krava je podeljeno u 2 grupe: kontrolna grupa od 6 krava i grupa od 10 krava hranjenih probiotikom u obroku. Buražna tečnost i uzorci krvi su sakupljeni 21 dan pre očekivanog teljenja, kao i 7, 15, 30, 45 i 60 dana tokom laktacije (days in milk - DIM). Prinos mleka za svaku životinju zabeležen je svake 2 nedelje. Pojedinačni uzorci mleka su prikupljeni 15, 30, 45 i 60 DIM. pH buraga i buražni amonijačni azot su bili značajno niži, dok su ukupne isparljive masne kiseline bile značajno veće kod životinja hranjenih kvascem u poređenju sa kontrolama kroz celu studiju. Serumske koncentracije ukupnih proteina i globulina bile su više, dok su koncentracije albumina bile niže u grupi sa kvascem. Serumski nivoi glukoze bili su značajno viši kod životinja sa dodatkom kvasca. Trigliceridi u serumu, koncentracije lipoproteina visoke i niske gustine bile su niže, sa holesterolom koji je bio znatno niži u tretiranoj grupi. Proizvodnja mleka i procent mlečne masti bili su viši, dok je sadržaj proteina mleka i somatskih ćelija bio niži u krava hranjenih sa dodatkom kvasca kroz celu studiju. Ovi rezultati ukazuju na to da dodatak S. cerevisiae u obrocima muznih krava tokom tranzicije i rane laktacije poboljšava njihovo zdravlje i parametre proizvodnje mleka
Prevalence of unmet contraceptive need among Egyptian women: a community-based study
Introduction. An estimated 17% of married women in the devel- oping world still have an unmet need for contraception. This study aimed to measure the prevalence and reasons for unmet contraceptive need among married women in the childbearing period in an underprivileged district in Eastern Cairo.
Methods. A cluster survey of 2340 women in the Marg district of Eastern Cairo was performed. Socio-demographic data and data on both past and present contraceptive use were obtained by interview questionnaire. Results. The prevalence of unmet need was 7.4%; 53.4% for limiting and 46.6% for spacing. Experience of side effects from contraceptive use, and fear of side effects, was highly prevalent among women with unmet need. In addition, a large proportion of women with unmet need perceived themselves not to be at risk for conceiving.
Conclusions. A substantial proportion of women in Cairo have unmet contraceptive need. Efficient counseling of women about contraception may help reduce this high prevalence
Uticaj dodatka Saccharomyces cerevisiae u ishrani na zdravlje i proizvodnju krava tokom perioda tranzicije i početka laktacije
Data concerning the effect of probiotics supplementation on many parameters concurrently at the same cows are lacking. Therefore, the objective of this experiment was to investigate the effects of Saccharomyces cerevisiae feeding on rumen, blood and milk parameters together in high- producing dairy cattle during the transition and early lactation period. Sixteen clinically healthy Holstein cows were divided into 2 groups: a control group of 6 cows and a probiotics-fed group of 10 cows. Rumen fluid and blood samples were collected 21 days before the expected calving as well as 7, 15, 30, 45 and 60 days- in-milk (DIM). Milk yield for each animal was recorded every 2 weeks. Individual milk samples were collected 15, 30, 45 and 60 DIM. Ruminal pH and rumen ammonia nitrogen were significantly lower, whereas total volatile fatty acids were significantly higher in yeast-fed animals compared with controls throughout the study. Serum concentrations of total proteins and globulins were higher, while albumins were lower in the yeast-treated group. Serum glucose levels were significantly higher in yeast-supplemented animals. Serum triglycerides, high density lipoproteins, and low density lipoproteins concentrations were lower, with cholesterol being significantly lower in the treated group. Milk production and milk fat percentage were higher, whereas milk protein percentage and somatic cell count were decreased in yeast-supplemented cows throughout the study. These results suggest that supplementation of S. cerevisiae to dairy cows rations during transition and early lactation period improve their health and milk production parameters.Podaci koji bi se odnosili na uticaj suplementacije probiotika na više parametara istovremeno na istim grlima nedostaju u literaturi. Stoga je cilj ovog eksperimenta bio da se ispita uticaj Saccharomices cerevisiae u obroku/hrani na parametre rumena, krvi i mleka zajedno u visoko-proizvodnim mlečnim govedima tokom tranzicije i početkom laktacije. Šesnaest klinički zdravih holštajn krava je podeljeno u 2 grupe: kontrolna grupa od 6 krava i grupa od 10 krava hranjenih probiotikom u obroku. Buražna tečnost i uzorci krvi su sakupljeni 21 dan pre očekivanog teljenja, kao i 7, 15, 30, 45 i 60 dana tokom laktacije (days in milk - DIM). Prinos mleka za svaku životinju zabeležen je svake 2 nedelje. Pojedinačni uzorci mleka su prikupljeni 15, 30, 45 i 60 DIM. pH buraga i buražni amonijačni azot su bili značajno niži, dok su ukupne isparljive masne kiseline bile značajno veće kod životinja hranjenih kvascem u poređenju sa kontrolama kroz celu studiju. Serumske koncentracije ukupnih proteina i globulina bile su više, dok su koncentracije albumina bile niže u grupi sa kvascem. Serumski nivoi glukoze bili su značajno viši kod životinja sa dodatkom kvasca. Trigliceridi u serumu, koncentracije lipoproteina visoke i niske gustine bile su niže, sa holesterolom koji je bio znatno niži u tretiranoj grupi. Proizvodnja mleka i procent mlečne masti bili su viši, dok je sadržaj proteina mleka i somatskih ćelija bio niži u krava hranjenih sa dodatkom kvasca kroz celu studiju. Ovi rezultati ukazuju na to da dodatak S. cerevisiae u obrocima muznih krava tokom tranzicije i rane laktacije poboljšava njihovo zdravlje i parametre proizvodnje mleka
Single-Atom Resolved Fluorescence Imaging of an Atomic Mott Insulator
The reliable detection of single quantum particles has revolutionized the
field of quantum optics and quantum information processing. For several years,
researchers have aspired to extend such detection possibilities to larger scale
strongly correlated quantum systems, in order to record in-situ images of a
quantum fluid in which each underlying quantum particle is detected. Here we
report on fluorescence imaging of strongly interacting bosonic Mott insulators
in an optical lattice with single-atom and single-site resolution. From our
images, we fully reconstruct the atom distribution on the lattice and identify
individual excitations with high fidelity. A comparison of the radial density
and variance distributions with theory provides a precise in-situ temperature
and entropy measurement from single images. We observe Mott-insulating plateaus
with near zero entropy and clearly resolve the high entropy rings separating
them although their width is of the order of only a single lattice site.
Furthermore, we show how a Mott insulator melts for increasing temperatures due
to a proliferation of local defects. Our experiments open a new avenue for the
manipulation and analysis of strongly interacting quantum gases on a lattice,
as well as for quantum information processing with ultracold atoms. Using the
high spatial resolution, it is now possible to directly address individual
lattice sites. One could, e.g., introduce local perturbations or access regions
of high entropy, a crucial requirement for the implementation of novel cooling
schemes for atoms on a lattice
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