2,010 research outputs found
A review on thermo-physical properties of bio, non-bio and hybrid nanofluids
The pressure drop and thermal performance of various nanofluids can be affected by their thermo-physical properties. However, there are many different parameters that need to be considered when determining the thermo-physical properties of nanofluids. This paper highlights a detail reviews on the thermo-physical properties of nanofluids with different material type and effect of some process parameters (such as material type, temperature and concentration) on the thermo-physical properties of nanofluids. Four thermo-physical properties mainly density, viscosity, thermal conductivity and specific heat capacity from different literatures were summarized, discussed and presented. The lowest viscosity value of nanofluids in literature was mango bark water-based nanofluid (0.81cP). On the other hand, the maximum thermal conductivity value of nanofluids in the literature was GNP-Ag water-based nanofluid (0.69W/mK). The density and specific heat capacity are strongly dependent on the material type. Meanwhile, the viscosity and thermal conductivity are greatly affected by temperature and concentration. The most influential parameters on thermo-physical properties of nanofluids are material type followed by temperature. Most of the literatures confirmed bio nanofluids have low viscosity value and hybrid have high thermal conductivity values
Decoherence and dephasing errors caused by D.C. Stark effect in rapid ion transport
We investigate the error due to D.C. Stark effect for quantum information
processing for trapped ion quantum computers using the scalable architecture
proposed in J. Res. Natl. Inst. Stan. 103, 259 (1998) and Nature 417, 709
(2002). As the operation speed increases, dephasing and decoherence due to the
D.C. Stark effect becomes prominent as a large electric field is applied for
transporting ions rapidly. We estimate the relative significance of the
decoherence and dephasing effects and find that the latter is dominant. We find
that the minimum possible of dephasing is quadratic in the time of flight, and
an inverse cubic in the operational time scale. From these relations, we obtain
the operational speed-range at which the shifts caused by D.C. Stark effect, no
matter follow which trajectory the ion is transported, are no longer
negligible. Without phase correction, the maximum speed a qubit can be
transferred across a 100 micron-long trap, without excessive error, in about 10
ns for Calcium ion and 50 ps for Beryllium ion. In practice, the accumulated
error is difficult to be tracked and calculated, our work gives an estimation
to the range of speed limit imposed by D.C. Stark effect.Comment: 7 pages, 1 figure. v2: Title is changed in this version to make our
argument more focused. Introduction is rewritten. A new section IV is added
to make our point more prominent. v3: Title is changed to make our argument
more specific. Abstract, introduction, and summary are revise
How general practitioners and patients discuss type 2 diabetes mellitus and cardiovascular diseases concerns during consultations: Implications for digital health
Objective: To analyse general practitionerâpatient consultations about type 2 diabetes mellitus or cardiovascular diseases and describe (i) the nature of self-management discussions; (ii) actions required from patients during and after consultation regarding self-management; and (iii) implications for digital health to support patients during (and after) consultation. Method: This study screened 281 general practitioner consultations conducted in 2017 within the UK general practice setting from an existing dataset containing videos and transcripts of consultations between GPs and patients. Secondary analysis was conducted using a multi-method approach, including descriptive, content, and visualisation analysis, to inform the nature of self-management discussions, what actions are required from patients, and whether digital technology was mentioned during the consultation to support self-management. Results: Analysis of eligible 19 consultations revealed a discord between what self-management actions are required of patients during and after consultations. Lifestyle discussions are often discussed in depth, but these discussions rely heavily on subjective inquiry and recall. Some patients in these cohorts are overwhelmed by self-management, to the detriment of their personal health. Digital support for self-management was not a major topic of discussion, however, we identified a number of emergent gaps where digital technology can support self-management concerns. Conclusion: There is potential for digital technology to reconcile what actions are required of patients during and after consultations. Furthermore, a number of emergent themes around self-management have implications for digitalisation
An alternative model for assessing mortality risk in Stevens Johnson syndrome/toxic epidermal necrolysis using a random forests classifier: A pilot study
IntroductionMortality risk prediction is an important part of the clinical assessment in the Stevens-Johnson syndrome and toxic epidermal necrolysis (SJS/TEN) patient. The SCORTEN and ABCD-10 scoring systems have been used as predictive clinical tools for assessing this risk. However, some of the metrics required in calculating these scores, such as the total body surface area (TBSA) involvement, are difficult to calculate. In addition, TBSA involvement is calculated in a variety of ways and is observer dependent and subjective. The goal of this study was to develop an alternative method to predict mortality in patients with SJS/TEN.MethodsData was split into training and test datasets and preprocessed. Models were trained using five-fold cross validation. Out of several possible candidates, a random forests model was evaluated as being the most robust in predictive power for this dataset. Upon feature selection, a final random forests model was developed which was used for comparison against SCORTEN.ResultsThe differences in both accuracy (p = 0.324) and area under the receiver operating characteristic curve (AUROC) (p = 0.318) between the final random forests model and the SCORTEN and ABCD-10 models were not statistically significant. As such, this alternative method performs similarly to SCORTEN while only requiring simple laboratory tests from the day of admission.DiscussionThis new alternative can make the mortality prediction process more efficient, along with providing a seamless implementation of the patient laboratory tests directly into the model from existing electronic health record (EHR) systems. Once the model was developed, a web application was built to deploy the model which integrates with the Epic EHR system on the Fast Healthcare Interoperability Resources (FHIR) Application Programming Interface (API); this only requires the patient medical record number and a date of the lab tests as parameters. This model ultimately allows clinicians to calculate patient mortality risk with only a few clicks. Further studies are needed for validation of this tool
Energy of Isolated Systems at Retarded Times as the Null Limit of Quasilocal Energy
We define the energy of a perfectly isolated system at a given retarded time
as the suitable null limit of the quasilocal energy . The result coincides
with the Bondi-Sachs mass. Our is the lapse-unity shift-zero boundary value
of the gravitational Hamiltonian appropriate for the partial system
contained within a finite topologically spherical boundary . Moreover, we show that with an arbitrary lapse and zero shift the same
null limit of the Hamiltonian defines a physically meaningful element in the
space dual to supertranslations. This result is specialized to yield an
expression for the full Bondi-Sachs four-momentum in terms of Hamiltonian
values.Comment: REVTEX, 16 pages, 1 figur
Size- and charge-dependent non-specific uptake of PEGylated nanoparticles by macrophages
The assessment of macrophage response to nanoparticles is a central component in the evaluation of new nanoparticle designs for future in vivo application. This work investigates which feature, nanoparticle size or charge, is more predictive of non-specific uptake of nanoparticles by macrophages. This was investigated by synthesizing a library of polymer-coated iron oxide micelles, spanning a range of 30â100 nm in diameter and â23 mV to +9 mV, and measuring internalization into macrophages in vitro. Nanoparticle size and charge both contributed towards non-specific uptake, but within the ranges investigated, size appears to be a more dominant predictor of uptake. Based on these results, a protease-responsive nanoparticle was synthesized, displaying a matrix metalloproteinase-9 (MMP-9)-cleavable polymeric corona. These nanoparticles are able to respond to MMP-9 activity through the shedding of 10â20 nm of hydrodynamic diameter. This MMP-9-triggered decrease in nanoparticle size also led to up to a six-fold decrease in nanoparticle internalization by macrophages and is observable by T2-weighted magnetic resonance imaging. These findings guide the design of imaging or therapeutic nanoparticles for in vivo targeting of macrophage activity in pathologic states
Energy efficiency analysis in office building through thermal modelling
Malaysia is hot and humid country with high temperature and humidity. The air conditioning systems that have huge energy consumption are an essential component in daily life. The aims of this research are to build a building thermal HVAC model, which could predict the amount of energy consumption required to get the comfort level using eQUEST and purpose energy saving methods. In the model the different physical properties of the building, weather, and internal load, HVAC system, operating strategies and schedules taken to account. From the result, huge energy used for space cooling resulting low room temperature outside the range of Malaysian Standard MS1525. Among the purposed method, packaged VAV DX coil air conditioning system has the most energy saving on the buildingâs overall energy consumption following by roof and wall insulation (24°C) indoor temperature, standard VAV CW coil air conditioning system, and daylight control with low e glass. The energy reduction range from 6.0% to 21.2%. This study are significant to study and improve the building energy efficiency
The effects of changes in the order of verbal labels and numerical values on children's scores on attitude and rating scales
Research with adults has shown that variations in verbal labels and numerical scale values on rating scales can affect the responses given. However, few studies have been conducted with children. The study aimed to examine potential differences in childrenâs responses to Likert-type rating scales according to their anchor points and scale direction, and to see whether or not such differences were stable over time. 130 British children, aged 9 to 11, completed six sets of Likert-type rating scales, presented in four different ways varying the position of positive labels and numerical values. The results showed, both initially and 8-12 weeks later, that presenting a positive label or a high score on the left of a scale led to significantly higher mean scores than did the other variations. These findings indicate that different arrangements of rating scales can produce different results which has clear implications for the administration of scales with children
Pseudotensors and quasilocal energy-momentum
Early energy-momentum investigations for gravitating systems gave reference
frame dependent pseudotensors; later the quasilocal idea was developed.
Quasilocal energy-momentum can be determined by the Hamiltonian boundary term,
which also identifies the variables to be held fixed on the boundary. We show
that a pseudotensor corresponds to a Hamiltonian boundary term. Hence they are
quasilocal and acceptable; each is the energy-momentum density for a definite
physical situation with certain boundary conditions. These conditions are
identified for well-known pseudotensors.Comment: LaTeX (REVTex), 4 pages, no figures, revised Title, abstract,
introduction and conclusio
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