10 research outputs found
Neutrino emission due to Cooper pairing of protons in cooling neutron stars: Collective effects
The process of neutrino-pair radiation due to formation and breaking of
Cooper pairs of protons in superconducting cores of neutron stars is considered
with taking into account of the electromagnetic coupling of protons to ambient
electrons. It is shown that plasma polarization strongly modifies the effective
vector weak current of protons. Collective response of ambient electrons to the
proton quantum transition contributes coherently to the complete interaction
with the neutrino field and enhances the rate of neutrino-pair production by
two orders of magnitude.Comment: 11 pages, 2 figure
Collective neutrino-pair emission due to Cooper pairing of protons in superconducting neutron stars
The neutrino emission due to formation and breaking of Cooper pairs of
protons in superconducting cores of neutron stars is considered with taking
into account the electromagnetic coupling of protons to ambient electrons. It
is shown that collective response of electrons to the proton quantum transition
contributes coherently to the complete interaction with a neutrino field and
enhances the neutrino-pair production. Our calculation shows that the
contribution of the vector weak current to the emissivity of
protons is much larger than that calculated by different authors without taking
into account the plasma effects. Partial contribution of the pairing protons to
the total neutrino radiation from the neutron star core is very sensitive to
the critical temperatures for the proton and neutron pairing. We show domains
of these parameters where the neutrino radiation, caused by a singlet-state
pairing of protons is dominating.Comment: 34 pages, including 9 figure
Vector current conservation and neutrino emission from singlet-paired baryons in neutron stars
Neutrino emission caused by singlet Cooper pairing of baryons in neutron
stars is recalculated by accurately taking into account for conservation of the
vector weak currents. The neutrino emissivity via the vector weak currents is
found to be several orders of magnitude smaller than that obtained before by
different authors. This makes unimportant the neutrino radiation from singlet
pairing of protons or hyperons.Comment: 5 pages, 1 figur
Comparative Techno-Economic Analysis of Carbon Capture Processes: Pre-Combustion, Post-Combustion, and Oxy-Fuel Combustion Operations
YesEvaluation of economic aspects is one of the main milestones that affect taking rapid actions in dealing with GHGs mitigation; in particular, avoiding CO2 emissions from large source points, such as power plants. In the present study, three kinds of capturing solutions for coal power plants as the most common source of electricity generation have been studied from technical and economic standpoints. Aspen HYSYS (ver.11) has been used to simulate the overall processes, calculate the battery limit, and assess required equipment. The Taylor scoring method has been utilized to calculate the costliness indexes, assessing the capital and investment costs of a 230 MW power plant using anthracite coal with and without post-combustion, pre-combustion, and oxy-fuel combustion CO2 capture technologies. Comparing the costs and the levelized cost of electricity, it was found that pre-combustion is more costly, to the extent that the total investment for it is approximately 1.6 times higher than the oxy-fuel process. Finally, post-combustion, in terms of maturity and cost-effectiveness, seems to be more attractive, since the capital cost and indirect costs are less. Most importantly, this can be applied to the existing plants without major disruption to the current operation of the plants
Aerobic Training, Resistance Training, or Their Combination as a Means to Fight against Excess Weight and Metabolic Syndrome in Obese StudentsâWhich Is the Most Effective Modality? A Randomized Controlled Trial
This study aimed to determine the effects of either aerobic training (AT) or resistance training (RT) or both (A+RT) on obesity and its comorbidities in young adults. A total of 61 participants, aged 21.74 1.42 years and with a body mass (BM) index (BMI) of 36.21 2.43 kg/m2, were randomized for 12 weeks into control (CONT, n = 14), AT (n =13), RT (n = 16), and A+RT (n = 14) groups. BM, body composition, and cardiovascular disease risk (CVR) factors were assessed before and after intervention. BM did not change in the CONT and RT groups but decreased significantly by 7.5 kg in the AT (p †0.05) and 8.82 kg in the A+RT (p †0.05) groups, respectively. Significant reductions were also noted in waist circumference, BMI, and body fat percentage in the exercising groups. The most significant variations were in the A+RT group. HDL-C concentrations were increased after A+RT by 2.39 mg/dL. Significant reductions were also noted in VLDL-C concentrations (â2.84 mg/dL) in the A+RT group. AT alone is effective in improving BM and body composition, while RT alone improves the body composition and A+RT ensures better outcomes concerning BM, body composition, HDL-C, and VLDL-C.
Novelty bullets:
âAerobic training alone is effective in improving body mass and body composition.
âResistance training alone improves the body composition.
âThe combination of aerobic and resistance exercises ensures better outcomes for body mass, body composition, HDL-C, and VLD-C.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author
Applying lean thinking concepts to new product development
Lean Thinking can be introduced in the enterprise to ensure an optimal transformation to a lean environment. There is a need in European manufacturing companies of a new model that implies a further stage of lean manufacturing. This paper outlines the first results of a current European project (LeanPPD-Lean Product and Process Development) which aims to develop a new paradigm with its associate methodology and tools based on applying lean thinking concepts in Product Design and Development field. To tackle this objective, a new model will be developed which consider entire product life cycle, providing knowledge based user-centric design and
development environment to support value creation to the customers in terms of innovation and customisation, quality as well as sustainable and affordable products. Several of the scientific and technical objectives settled have already met. This paper constitutes a whole explanation of the LeanPPD model proposed by the project consortium and outlines its four main building blocks providing better understanding on how the project addresses these objectives
Substantiation of 25Â kGy radiation sterilization dose for banked air dried amniotic membrane and evaluation of personnel skill in influencing finished product bioburden
Preparation of amniotic membrane (AM) by air drying method followed by radiation sterilization is simple and valuable approach; sterility and quality of the final AM product are depending on the quality management system at the tissue bank. Validation and substantiation of radiation sterilization dose (RSD) for tissue allografts is an essential step for the development and validation of the standard operating procedures (SOP). Application of SOP is perfectly relying on trained staff. Skills differences among personnel involved in AM preparation could have an effect on microbiological quality of the finished product and subsequently on the RSD required. AM were processed by four different couples of the tissue bank technicians. The AM grafts were randomly selected and subjected to bioburden test to validate and substantiate the 25 kGy RSD. Bioburden test for AM grafts were also useful to evaluate the skill of the tissue bank technicians and thus, to validate the current SOP for air dried AM. Moreover, the effect of placental source on bioburden counts on AM grafts was assessed. Substantiation of the 25 kGy RSD at a sterility assurance level of 10(â1), and sample item portion = 1, was carried out using Method VD(max)(25) of the International Organization for Standardization, document no. 11137-2 (ISO in Sterilization of healthcare productsâradiationâpart 2: establishing the sterilization dose, Method VDmaxâsubstantiation of 25 kGy or 15 kGy as the sterilization dose, International Standard Organization, 2006). The results showed that there were no significant differences in the bioburdens of the four batches (α = 1 %), this means no significant differences in the skill of the four couples of the tissue bank technicians in terms of their ability to process AM according to the air dried AM SOP. The 25 kGy RSD was validated and substantiated as a valid sterilization dose for the AM prepared with the current established SOP at the Biotechnology Research Center experimental tissue bank. The donorâs type of delivery, normal or caesarean, showed no significant effect on the levels of microbial counts on the tested AMs (α = 1 %)