1,250 research outputs found
Efficient all-optical production of large Li quantum gases using D gray-molasses cooling
We use a gray molasses operating on the D atomic transition to produce
degenerate quantum gases of Li with a large number of atoms. This
sub-Doppler cooling phase allows us to lower the initial temperature of 10
atoms from 500 to 40 K in 2 ms. We observe that D cooling remains
effective into a high-intensity infrared dipole trap where two-state mixtures
are evaporated to reach the degenerate regime. We produce molecular
Bose-Einstein condensates of up to 510 molecules and
weakly-interacting degenerate Fermi gases of 10 atoms at
with a typical experimental duty cycle of 11 seconds.Comment: 5 pages, 3 figure
EVALUASI IMPLEMENTASI KEBIJAKAN OTONOMI PENDIDIKAN DARI DINAS PENDIDIKAN KABUPATEN/KOTA KE DINAS PENDIDIKAN PROPINSI KALIMANTAN TIMUR
The objectives of the research are to: (1) find out the effectiveness of the implementation of education autonomy policy from regency / city to province; (2) to know the effectiveness of the realization of education budget; (3) to know the effectiveness of quality improvement of education quality; (4) to know politicization; And (5) finding new strategies for implementing education autonomy policies. The study used the Tyler model evaluation study. Level of effectiveness using percentages. Qualitative data were analyzed with McMilland model. The validity of qualitative data uses credibility, dependability, transferability, and confirmability.The study concluded: (1) the implementation of education policy autonomy is about 50% (quite effective), qualitatively ineffective; (2) the realization of the education budget is 25% (not effective) and also qualitatively ineffective; (3) teacher quality improvement 65.30% (effective), qualitatively ineffective; (4) teacher politicization hampers the professionalism and career development of teachers, shifts the politicization of teachers from districts / municipalities to the politics of what, when, and how to get something, no true friend of true interest, art of possibility, way; (5) the new strategy for streamlining the implementation of education autonomy policy is 8K in bebay
Connecting dissipation and phase slips in a Josephson junction between fermionic superfluids
We study the emergence of dissipation in an atomic Josephson junction between
weakly-coupled superfluid Fermi gases. We find that vortex-induced phase
slippage is the dominant microscopic source of dissipation across the BEC-BCS
crossover. We explore different dynamical regimes by tuning the bias chemical
potential between the two superfluid reservoirs. For small excitations, we
observe dissipation and phase coherence to coexist, with a resistive current
followed by well-defined Josephson oscillations. We link the junction transport
properties to the phase-slippage mechanism, finding that vortex nucleation is
primarily responsible for the observed trends of conductance and critical
current. For large excitations, we observe the irreversible loss of coherence
between the two superfluids, and transport cannot be described only within an
uncorrelated phase-slip picture. Our findings open new directions for
investigating the interplay between dissipative and superfluid transport in
strongly correlated Fermi systems, and general concepts in out-of-equlibrium
quantum systems.Comment: 6 pages, 4 figures + Supplemental Materia
Emergence of turbulence in an oscillating Bose-Einstein condensate
We report on the experimental observation of vortices tangle in an atomic BEC
of Rb-87 atoms when an external oscillatory perturbation is introduced in the
trap. The vortices tangle configuration is a signature of the presence of a
turbulent regime in the cloud. We also show that this turbulent cloud has
suppression of the aspect ratio inversion typically observed in quantum
degenerate bosonic gases during free expansion. Instead, the cloud expands
keeping the ratio between their axis constant. Turbulence in atomic superfluids
may constitute an alternative system to investigate decay mechanisms as well as
to test fundamental theoretical aspects in this field.Comment: accepted for Phys. Rev. Let
Green Application: Electric Charge Generated From Any High Temperature Heat Source
The prime objective of the environmental friendly project ECO Electro Green device is to decrease the amount of carbon monoxide in the air and thereby to bring down the air pollution and save the environment. The proposed system will use natural gas (propane burner) as an alternate conversion energy source to generate electrical charges, particularly in forest and coastal areas. The demonstration shows that the system, when functioning under optimum conditions, has the potential to generate significant amount of electrical charges. For the project, dynamo, heater, cooler, piping systems and flywheel were designed, constructed and then analyzed. The current system was then set up using an external heat source as it can run on any source that makes heat as natural gas. To conclude, this system is the new methodology for generating electric charges that reduce pollution and save electrical cost
Current implementation of advance encryption standard (AES) S-Box
Although the attack on cryptosystem is still not severe, the development of the scheme is stillongoing especially for the design of S-Box. Two main approach has beenused, which areheuristic method and algebraic method. Algebraic method as in current AES implementationhas been proven to be the most secure S-Box design to date. This review paper willconcentrate on two kinds of method of constructing AES S-Box, which are algebraic approachand heuristic approach. The objective is to review a method of constructing S-Box, which arecomparable or close to the original construction of AES S-Box especially for the heuristicapproach. Finally, all the listed S-Boxes from these two methods will be compared in terms oftheir security performance which is nonlinearity and differential uniformity of the S-Box. Thefinding may offer the potential approach to develop a new S-Box that is better than theoriginal one.Keywords: block cipher; AES; S-Bo
Wideband jean antenna with bending structure for microwave imaging applications
In this paper, a wideband jean antenna with bending structure for flexible microwave imaging applications is presented. Coplanar waveguide (CPW) feeding structure with Koch shape ground slotted technique has been implemented for widening the bandwidth. The design evolution process of the proposed antenna is started from a simple CPW-fed monopole antenna to bending circumstance. The proposed antennas under normal condition, bending circumstance and as well as on-arm bending effect are simulated and optimized using CST microwave studio software and fabricated; also tested so as to validate the results. Under normal condition, the antenna provides measured bandwidth of 4500 MHz (1.5-6 GHz) in the case of |S11|≤−10 dB while 4360 MHz (1.44-5.8 GHz) for the measured bandwidth under bending circumstance is obtained. Also, there is a slight degradation on the reflection coefficient of the antenna under on-arm bending so that measured bandwidth became narrower with operating frequency of 3800 MHz (2.2-6 GHz). The measured gain of the antenna fluctuates between 2.5-5.6 dBi and 1.5-2.8 dBi with quasi-omnidirectional pattern within the expected frequency band for normal and bending condition, respectively. The proposed antenna provides a good performance in terms of its reflection coefficient and radiation characteristics. Therefore, due to insensitiveness to bending and body effect, the proposed antenna has become good candidate for microwave imaging applications
Regression Analysis for the Adsorption Isotherms of Betacyanin Extracts from the Dragon Fruit Peel onto the Spun Silk Yarn
The betacyanin pigment extracted from the dragon fruit peel has a potential to be a natural dye as an alternative to replace the synthetic dyes. To investigate the dyeability of spun silk with betacyanin pigment, the adsorption isotherm models were performed. The equilibrium adsorption data were analyzed using the Langmuir, Freundlich, and Temkin isotherm models. In order to determine the best-fit isotherm for each system, three error analysis methods were used to evaluate the data, namely the sum of the squares of the errors, residual root mean square error and chi-square test. On the basis of low three error analysis and high correlation of determination, it was found that the Langmuir isotherm model fitted well with the experimental data. Therefore, it can be concluded that the adsorption process of betacyanin pigment onto the spun silk followed the Langmuir isotherm model. Moreover, the adsorption features of the experimental system might be caused by the monolayer adsorption
An Improved Optimization Model of Internet Charging Scheme in Multi Service Networks
This article will analyze new improved charging scheme with base price, quality premium and QoS networks involved. Sain and Herpers [5] already attempted to obtain revenue maximization by creating charging scheme of internet. The plan is attempted to solve multi service networks scheme as an optimization model to obtain revenue maximization using our improved model based on Byun and Chatterjee [2] and Sain and Herpers [5]. The results show that improved model can be solved optimally using optimization tool LINGO to achieve better revenue maximization. Better results are obtained in all cases rather than in [5]. The advantage of our new model is that ISP also can set up their base price and quality premium based on ISP preferences. For some cases for getting revenue maximization, we do not offer one service and just utilize some of the services
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