Cooling a quantum circuit via coupling to a multiqubit system

The cooling effects of a quantum LC circuit coupled inductively with an ensemble of artificial qubits are investigated. The particles may decay independently or collectively through their interaction with the environmental vacuum electromagnetic field reservoir. For appropriate bath temperatures and the resonator's quality factors, we demonstrate an effective cooling well below the thermal background. In particular, we found that for larger samples the cooling efficiency is better for independent qubits. However, the cooling process can be faster for collectively interacting particles.Comment: 5 pages, 3 figure

Quantum tunneling through vacuum-multiparticle induced potentials

The vacuum cavity mode induces a potential barrier and a well when an ultra-slow excited atom enters the interaction region so that it can be reflected or transmitted with a certain probability. We demonstrate here that a slow-velocity excited particle tunnels freely through a vacuum electromagnetic field mode filled with $N-1$ ground state atoms. The reason for this is the trapping of the moving atom into its upper state due to multiparticle influences and the corresponding decoupling from the interaction with the environment such that the emitter does not {\it see} the induced potentials.Comment: Multiparticle samples, quantum tunneling, vacuum induced potential

APPLIED MARKETING RESEARCH REGARDING THE BUYING BEHAVIOR OF CUSTOMERS IN TRANSYLVANIA TOWARDS DAIRY PRODUCTS

The paper centers around an applied marketing research regarding the buying behavior of customers in Transylvania towards dairy products. The method used was the survey and the instrument used was the questionnaire. The research was done on a swatch of 300 subjects, all target customers from Transylvania, selected by a nonrandom method - accessibility. The objective of the survey is to identify the customers knowledge and attitudes towards dairy products, establish the power of the brands and the impact of marketing. Furthermore, the study conducted reveals that in the near future there is a tendency for growth in the bio segment of dairy products. This is due to a change in mentality, while in the past customers were favoring low price over product quality; nowadays more customers from Transylvania are willing and able to spend more in order to buy a better dairy product

Liquid chromatographic method for the determination of beta-carotene from milk and cheese

The beta-carotene content in milk and cheese is an accurate indicator for the feeding method used for cows. It can also be sued as an indicator of adulteration of goat and other types of milk with cow milk. A high accuracy HPLC-UV method for the determination of beta-carotene from milk and cheese has been developed. After saponification with an alcoholic solution of potassium hydroxide the samples where extracted with a mixture of hexane: ethyl acetate (70:30) was used. The concentrated extract was analyzed using Perkin Elmer 200 Series High Performance Liquid Chromatograph (HPLC) with UV detector for the determination of beta-carotene content. The calibration was done in 4 points from 1-20 ng/ml. The recovery yield was between 73,8-89,7 %. The method was tested on 3 milk samples and 5 cheese samples. The highest concentration of beta-carotene was found in cheddar cheese produced with milk from pasture raised cows. 

Flexible generation of correlated photon pairs in different frequency ranges

The feasibility to generate correlated photon pairs at variable frequencies is investigated. For this purpose, we consider the interaction of an off-resonant laser field with a two-level system possessing broken inversion symmetry. We show that the system generates non-classical photon pairs exhibiting strong intensity-intensity correlations. The intensity of the applied laser tunes the degree of correlation while the detuning controls the frequency of one of the photons which can be in the THz-domain. Furthermore, we observe the violation of a Cauchy-Schwarz inequality characterizing these photons.Comment: 5 pages, 4 figure

STUDY ON FACTORS THAT INFLUENCE WATER EROSION ON AGRICULTURAL LAND - REVIEW

Soil erosion is a global threat to the natural resources and is particularly responsible for reduction in crop yield due to reduction in land productivity and storage capacity of multipurpose reservoirs due to continuous siltation (Rupesh Jayaram Patil, 2018). Soil erosion is process of soil loss. Particularly from the surface, but sometimes a large mass of soil may be lost, as in landslides and riverbank erosion. Soil erosion processes are mainly caused by two mechanisms: raindrop impact and surfacewash resulting fromwater in excess of infiltration (Ellison, 1947). Soil erosion is determined by a number of factors such as: relief, climate, soil and solidification rock, vegetation. Soil erosion is a natural process, occurring over geological time, and most concerns about erosion are related to accelerated erosion, where the natural rate has been significantly increased by human activity. Soil erosion poses severe limitations to sustainable agricultural land use, as it reduces on-farm soil productivity and causes the accumulation of sediments and agro-chemicals in waterways

On reducing uncertainty on the Elliptical Plane modal identification method

The Elliptical Plane has been recently introduced as a modal identification method that uses an alternative plot of the receptance. The method uses the dissipated energy per cycle of vibration as a starting point. For lightly damped systems with conveniently spaced modes, it produces quite accurate results, especially when compared to the well-known method of the inverse. When represented in the Elliptical Plane, the shape of the receptance is elliptical near resonant frequencies. The modal damping factor can be determined from the angle of the ellipse’s major axis with the horizontal axis, whereas the real and imaginary parts of the modal constants can be determined from numerical curve-fitting (as in the method of the circle - Nyquist plot). However, the lack of points that can be used near the resonance (due to limitations in the frequency resolution, and effects from other modes near each resonance) and the fact that measurements are polluted by noise, bring uncertainty to the numerical curve-fitting. This paper aims at providing the first steps on the improvement of the quality of the modal identification of the receptance in the Elliptical Plane. The method and results are discussed with a multiple degree-of-freedom numerical example

On the electromagnetic shielding properties of carbon fiber materials

Introduction. Due to the good electrical and thermal properties of carbon, carbon-based materials represent a major trend is various applications, including electromagnetic compatibility. Among carbon-based materials, graphite-impregnated woven fabrics represent a new trend in the field of electromagnetic shielding, with the perspective of being used for protective clothing. The novelty of the proposed work consists in the exhaustive comparative analysis of various carbon-based sample shields by employing both simulation and experimental methods. The selected configurations included a simple graphite plate, a graphite powder strip network, and a graphite-impregnated fabric with 2´2 twill weave. Purpose. The main scope of the analysis is to prove the efficiency of the graphite-impregnated twill woven fabric in the field of electromagnetic shielding. Methods. Two main research methods were employed: simulation and experiment, both following the same protocol: the shield placed in the middle, with the excitation (transmitting antenna) on one side and the measurement / receiving antenna on the other. The experimental stage was thorough, being performed in two different laboratories and by applying the double transverse electromagnetic (TEM) cell method and the shielded box method. Results. A significant difference yielded from the comparison of the simulation and experimental results for the shielding effectiveness, probably due to the fact that the virtual model is an idealized version of the physical one, not taking into account its imperfections. The virtual analysis yielded the graphite plate shield as the most efficient, followed closely by the twill fabric. The graphite strip network had significantly poorer performance compared to the other two shields, probably due to the electrical contact imperfections between the graphite strips and the optical transparency of the shield. The main focus of the analysis was the twill woven graphite-impregnated fabric; therefore, its shielding effectiveness was determined through simulation and experiment. The experimental analysis was performed in two stages in two different electromagnetic compatibility laboratories, by employing the double TEM cell method and the shielded box method, respectively, both methods providing similar results and classifying the shielding performance as good. Practical value. The paper provides an accurate analysis of the graphite-impregnated 2´2 twill woven fabric in terms of electromagnetic shielding effectiveness, by employing both simulation and experimental methods, and comparing its performance to the one other graphite-based shields.Вступ. Завдяки хорошим електричним і тепловим властивостям вуглецю, вуглецевмісні матеріали являють собою основні напрямки у різних застосуваннях, у тому числі в області електромагнітної сумісності, завдяки хорошим екрануючим властивостям. Серед матеріалів на основі вуглецю просочені графітом тканини є новою тенденцією в області електромагнітного екранування з перспективою використання для захисного одягу. Новизна запропонованої роботи полягає у вичерпному порівняльному аналізі різних зразків екранів на основі вуглецю з використанням як моделювання, так і експериментального методів. Вибрані конфігурації включали просту графітову пластину, сітку зі смуг з графітового порошку і просочену графітом тканину з переплетенням саржею 2´2. Ціль. Основною метою аналізу є доказ ефективності саржевого полотна, просоченого графітом, у галузі електромагнітного екранування. Методи. Використовувалися два основних методи дослідження: моделювання та експеримент, обидва слідували одному й тому ж протоколу: екран розташовувався посередині, з збуджуванням (передаючою антеною) з одного боку і вимірювальною/приймальною антеною з іншого. Експериментальний етап був ретельним і проводився у двох різних лабораторіях із застосуванням методу подвійної поперечної електромагнітної (ПЕМ) комірки та методу екранованої скриньки. Результати. Порівняння результатів моделювання та експериментів стосовно ефективності екранування демонструє суттєву відмінність, ймовірно, через те, що віртуальна модель є ідеалізованою версією фізичної, не враховуючи її недосконалості. Віртуальний аналіз показав, що екран із графітових пластин є найбільш ефективним, за ним близько слідує саржева тканина. Мережа з графітових смуг мала значно гірші характеристики порівняно з двома іншими екранами, ймовірно, через недосконалість електричного контакту між графітовими смужками та оптичною прозорістю екрана. Основним предметом аналізу була тканина саржевого переплетення, просочена графітом; тому її ефективність екранування визначалася шляхом моделювання та експерименту. Експериментальний аналіз був виконаний у два етапи у двох різних лабораторіях електромагнітної сумісності з використанням методу подвійної ПЕМ комірки та методу екранованої скриньки, відповідно, обидва методи дали аналогічні результати та визначили характеристики екранування як хороші. Практична цінність. У статті наведено точний аналіз просоченої графітом саржевої тканини 2´2 з точки зору ефективності електромагнітного екранування з використанням як моделювання, так і експериментальних методів, а також порівняння її характеристик з іншими екранами на основі графіту

Post-bariatric contour deformity correction: an endeavour to establish objective criteria nationally.

BACKGROUND A marked increase in bariatric surgery has led to higher numbers of patients with contour deformities after massive weight loss seeking plastic surgical correction. Insurance coverage for these post-bariatric interventions is highly subjective and a common set of objective criteria has not yet been established. AIM The aim was to evaluate the factors influencing insurance coverage for post-bariatric surgery, focusing on finding objective, reproducible criteria. METHODS This was a retrospective single centre chart review of all post-bariatric patients with redundant skin requesting body contouring surgery from 2013 to 2018. Demographic, bariatric and surgical, as well as insurance information were collected. A logistic regression model was used to identify predictors of successful insurance coverage. RESULTS 116 Patients were included in the study. Insurance approval for post-bariatric body contouring surgery was obtained for only 47 patients (41%). Mentioning the term "medical indication" in the application letter was associated with a 15.2 times higher rate of receiving a positive answer (p <0.001), whereas mentioning "mental suffering" was associated with 82.3% lower chance of getting a positive response (p <0.001). A high body mass index (BMI) (p <0.009) before the bariatric operation as well as a high BMI reduction (p <0.021) were associated with a higher approval rate by insurance companies . An additional application letter to the insurance company (p <0.024) as well as mentioning mechanical restriction (p <0.022) were associated with a positive response from the insurance companies. CONCLUSIONS We were able to establish certain objective predictive criteria for insurance coverage of post-bariatric surgery. However, it appears that the decisions of insurance companies for this condition are still rather randomly taken. Therefore, the establishment of objective criteria for insurance coverage may allow fairer treatment for this growing patient population

Spatial analysis of locational conflicts: case study: locational conflicts generated by the expansion of built up surfaces in the northern area of Bucharest, Romania

The aim of this paper is to identify and analyze land use conflicts existing in the northern area of Bucharest and to spatially model their impact on the expandint residential areas. The main objectives are: 1) to analyze the dynamics of built up surfaces between 1975-2010; 2) to analyze the spatial and temporal dynamic of locational conflicts and 3) to spatially model the impact of locational conflicts on residential areas.Peer Reviewe