3,557 research outputs found
Acoustic determination of thermophysical properties and critical parameters for R404A and critical line of x CO2+(1− x) R404A
The thermophysical properties and critical parameters for the alternative refrigerant R404A (52 wt % of 1,1,1-
trifluoroethane (R143a) + 44 wt % of pentafluoroethane (R125) + 4 wt % of 1,1,1,2-tetrafluoroethane (R134a))
were investigated using two different acoustic techniques. The critical behavior of the system xCO2 +
(1 - x)R404A was also investigated. Experimental data of speed of sound in liquid R404A from 258 K to
338 K and pressures up to 65 MPa were measured using a pulse-echo method. Derived thermodynamic properties
are calculated, combining our experimental data with density and isobaric heat capacity values published by
other authors. Measurements of the critical temperature Tc and pressure pc on (R404A) and mixtures of xCO2 +
(1 - x)R404A were performed using another simple ultrasonic time-delay technique. The binary critical line was
determined over the whole composition range showing that this system deviates only slightly from ideality since
the critical line is a continuous line. The Peng-Robinson equation of state with conventional mixing and combining
rules was used to correlate the binary experimental data.info:eu-repo/semantics/publishedVersio
Acoustic determination of thermophysical properties and critical parameters for R410A and critical line of x CO2+(1− x) R410A
The thermophysical properties and critical parameters for the alternative refrigerant R410A (a near azeotropic
refrigerant mixture containing difluoromethane (R32) and pentafluoroethane (R125) (50 wt % of each)) were
investigated using two different acoustic techniques. The critical behavior of the system xCO2 + (1 - x)R410A
was also investigated. Experimental data of speed of sound in liquid R410A from (253 to 338) K and pressures
up to 65 MPa were measured using a pulse-echo method. Derived thermodynamic properties were calculated,
combining our experimental data with density and isobaric heat capacity values published by other authors.
Measurements of the critical temperature Tc and pressure pc on (R410A) and mixtures of xCO2 + (1 - x)R410A
were performed using another simple ultrasonic time-delay technique. The binary critical line was determined
over the whole composition range, showing that this system deviates only slightly from ideality since the critical
line is a continuous line. The Peng-Robinson equation of state with conventional mixing and combining rules
was used to correlate the binary experimental data.info:eu-repo/semantics/publishedVersio
Analysis Of Requirements And Solutions
Several companies have been developing domotic Stds. for building automation, enabling users to locally
and remotely control several home devices, like: lights, power sockets, heating, ventilation, and air conditioning
systems, among others. Besides contributing to improve the building comfort, these Stds. may also
be adopted for other purposes, namely in weblabs used in sciences and engineering remote experiments. To
increase the sense of immersion in weblabs, we identify domotic Stds. as a standard solution for turning
on/off the power infrastructure and controlling the light and temperature conditions of the physical space
where a specific experiment may run, thus approaching the sense of being in the lab facilities while accessing
them through the corresponding weblab interface. After identifying the added value to weblabs in terms
of power savings and in the control of the environmental conditions, we used our knowledge and the WWW
to conduct an extensive search on domotic Stds., and after analysing the results obtained, we choose the
most appropriated one to be implemented in a Weblab. Regarding the adopted Std., a proof-of-concept is
also described, enabling the control of an halogen lamp and a power socket, using a specific Web interface.info:eu-repo/semantics/publishedVersio
Silk fibroin based magnetic nanocomposites for actuator applications
The need for technologies based environmentally friendlier materials, able to minimize the global dependence on fossil fuel derivatives, promotes the development of new hybrid materials based on natural polymers, such as silk derivatives. This work reports on a new generation of magnetically active materials based on silk fibroin (SF) from Bombyx mori silkworm. Magnetic cobalt ferrite (CFO) nanoparticles are introduced in an SF polymer matrix to develop CFO/SF nanocomposites with filler contents of up to 20 wt%. It is shown that the inclusion of CFO nanoparticles affects the β‐sheet conformation of SF polymer having relevant effect on mechanical and thermal properties. The incorporation of conductive nanoparticles into nonconductive matrix, induces an increase in electric conductivity and also in dielectric constant. The primitive magnetic behavior of CFO nanoparticles is successfully maintained after their incorporation into SF, which has made possible the processing of magnetic SF. These results enable the design and fabrication of a fully functional magnetic actuator based on SF, proving the suitable natural polymer‐based magnetic materials for a new generation of environmental‐friendlier smart and multifunctional materialsFundação para a Ciência e Tecnologia. Grant Numbers: UID/FIS/04650/2019, UID/EEA/04436/2019, UID/QUI/0686/2019, PTDC/FIS-MAC/28157/2017, PTDC/BTM-MAT/28237/2017, SFRH/BD/131729/2017, SFRH/BPD/112547/2015 Spanish Ministry of Economy and Competitiveness. Grant Number: MAT2016-76039- C4-3-R
Basque Government Industry and Education Departments. Grant Number: PIBA- 2018-0
Telemedicina: Situação em Portugal
Introdução: A telemedicina é hoje
reconhecida pela OMS como uma ferramenta
para melhorar o acesso e a qualidade
dos cuidados de saúde. Apesar das vantagens aparentes é uma tecnologia recente e está longe de constituir uma prática de rotina na vida clínica diária.
Objectivo: Conhecer a situação actual em Portugal relativamente à telemedicina,
nomeadamente: quais as Unidades de Saúde com instalações de telemedicina e áreas em que se desenvolve esta actividade; número de serviços anuais e evolução; dificuldades e obstáculos dos profissionais e Instituições;
perspectivas futuras Metodologia: A recolha dos dados foi efectuado através de: inquérito enviados às ARS do Norte, Centro, Lisboa e Vale do Tejo, Alentejo, Algarve e IGIF; entrevista com algumas instituições relativa aos serviços em funcionamento;
pesquisa bibliográfica e na Internet
Resultados: Dos 6 inquéritos enviados foram recebidos 5, provenientes da ARS Norte, Centro, Lisboa e Vale do Tejo, Algarve e Alentejo. Foram efectuadas entrevistas: H S. João, CHVila Nova de Gaia, CHVale do Sousa e H Pediátrico de Coimbra. Obtivemos informações relativas aos equipamentos
instalados e serviços actualmente em
funcionamento, em todo o país, destacando-
se o funcionamento nas áreas da cardiologia, imagiologia e dermatologia.
Não havia registo do número de teleconsultas e transmissão de exames excepto no que se refere à ARS Alentejo.
Das dificuldades e obstáculos encontrados
salientamos a falta de adesão dos
profissionais e instituições; custos do
funcionamento do sistema; ausência de
definição funcional dos profissionais
envolvidos (falta de remuneração dos
actos médicos e acumulação de funções); ausência de uma estratégia nacional. Quanto às perspectivas futuras, de um modo geral, os objectivos das ARS incluem: a ligação dos centros de saúde e hospitais, e petrechamento
com um equipamento básico de Telemedicina
em conformidade com as actividades e tipos de consulta a realizar; o desenvolvimento de projectos no âmbito do INTERREG III.
Comentários: O desafio que as organizações tem que enfrentar é a mudança estrutural provocada pela modernização dos processos e métodos de trabalho, «o hospital virtual», e a diluição das barreiras entre os Cuidados
Primários e os Diferenciados. A telemedicina
exige novas formas de gestão e de medição de desempenho das instituições; esta actividade deve ser equiparada às outras normalmente
desenvolvidas nas unidades de saúde. Introduction: Telemedicine is recognized
by the WHO as a tool for improvement
of access and the quality of health
care. However it is not yet a routine
procedure in health services.
Objective: to assess the utilization
of telemedicine in Portugal, namely:
health care services equipped with
telemedicine, and services provided;
annual services and evolution; difficulties
and obstacles from professionals and
institutions; future trends
Methodology: data was obtained
through a questionnaire sent to the five
Regional Administrations of Health and
the Financial Department of Health, interviews
with some of the professionals
practising Telemedicine and research in
the web
Results: We received five questionnaires
from the Regional Administrations
of Health, and collected data
from the following Hospitals: S. João,
Vila Nova de Gaia, Vale do Sousa e
Coimbra Children’s Hospital.
We obtained information of the
institutions practising telemedicine, and
the type of services. Cardiology, radiology
and dermatology were the services more
frequently provided. The number of teleconsultations
or transmitted studies was
not registered, except in Alentejo. The
more common difficulties to implement
this technology were: clinical and providers
acceptance; lack of integration into
the health care mainstream (the costs of
teleconsultations are not reimbursed);
equipment and operational costs; absence
of a national strategy. Future trends
include the equipment of telemedicine
stations in Primary and Hospital care and
the development of projects in cooperation
with Spain (INTERREG III).
Comments: Organizations face the
challenge of a structural change due to
the new technologies (telemedicine and
health informatics) and the disappearance
of barriers between primary and
hospital care. Institutional, organizational
and national policies must face new
realities to introduce telemedicine into
the mainstream of health, including
assessment of health outcomes
Telemedicina: Situação em Portugal
Introdução: A telemedicina é hoje
reconhecida pela OMS como uma ferramenta
para melhorar o acesso e a qualidade
dos cuidados de saúde. Apesar das vantagens aparentes é uma tecnologia recente e está longe de constituir uma prática de rotina na vida clínica diária.
Objectivo: Conhecer a situação actual em Portugal relativamente à telemedicina,
nomeadamente: quais as Unidades de Saúde com instalações de telemedicina e áreas em que se desenvolve esta actividade; número de serviços anuais e evolução; dificuldades e obstáculos dos profissionais e Instituições;
perspectivas futuras Metodologia: A recolha dos dados foi efectuado através de: inquérito enviados às ARS do Norte, Centro, Lisboa e Vale do Tejo, Alentejo, Algarve e IGIF; entrevista com algumas instituições relativa aos serviços em funcionamento;
pesquisa bibliográfica e na Internet
Resultados: Dos 6 inquéritos enviados foram recebidos 5, provenientes da ARS Norte, Centro, Lisboa e Vale do Tejo, Algarve e Alentejo. Foram efectuadas entrevistas: H S. João, CHVila Nova de Gaia, CHVale do Sousa e H Pediátrico de Coimbra. Obtivemos informações relativas aos equipamentos
instalados e serviços actualmente em
funcionamento, em todo o país, destacando-
se o funcionamento nas áreas da cardiologia, imagiologia e dermatologia.
Não havia registo do número de teleconsultas e transmissão de exames excepto no que se refere à ARS Alentejo.
Das dificuldades e obstáculos encontrados
salientamos a falta de adesão dos
profissionais e instituições; custos do
funcionamento do sistema; ausência de
definição funcional dos profissionais
envolvidos (falta de remuneração dos
actos médicos e acumulação de funções); ausência de uma estratégia nacional. Quanto às perspectivas futuras, de um modo geral, os objectivos das ARS incluem: a ligação dos centros de saúde e hospitais, e petrechamento
com um equipamento básico de Telemedicina
em conformidade com as actividades e tipos de consulta a realizar; o desenvolvimento de projectos no âmbito do INTERREG III.
Comentários: O desafio que as organizações tem que enfrentar é a mudança estrutural provocada pela modernização dos processos e métodos de trabalho, «o hospital virtual», e a diluição das barreiras entre os Cuidados
Primários e os Diferenciados. A telemedicina
exige novas formas de gestão e de medição de desempenho das instituições; esta actividade deve ser equiparada às outras normalmente
desenvolvidas nas unidades de saúde. Introduction: Telemedicine is recognized
by the WHO as a tool for improvement
of access and the quality of health
care. However it is not yet a routine
procedure in health services.
Objective: to assess the utilization
of telemedicine in Portugal, namely:
health care services equipped with
telemedicine, and services provided;
annual services and evolution; difficulties
and obstacles from professionals and
institutions; future trends
Methodology: data was obtained
through a questionnaire sent to the five
Regional Administrations of Health and
the Financial Department of Health, interviews
with some of the professionals
practising Telemedicine and research in
the web
Results: We received five questionnaires
from the Regional Administrations
of Health, and collected data
from the following Hospitals: S. João,
Vila Nova de Gaia, Vale do Sousa e
Coimbra Children’s Hospital.
We obtained information of the
institutions practising telemedicine, and
the type of services. Cardiology, radiology
and dermatology were the services more
frequently provided. The number of teleconsultations
or transmitted studies was
not registered, except in Alentejo. The
more common difficulties to implement
this technology were: clinical and providers
acceptance; lack of integration into
the health care mainstream (the costs of
teleconsultations are not reimbursed);
equipment and operational costs; absence
of a national strategy. Future trends
include the equipment of telemedicine
stations in Primary and Hospital care and
the development of projects in cooperation
with Spain (INTERREG III).
Comments: Organizations face the
challenge of a structural change due to
the new technologies (telemedicine and
health informatics) and the disappearance
of barriers between primary and
hospital care. Institutional, organizational
and national policies must face new
realities to introduce telemedicine into
the mainstream of health, including
assessment of health outcomes
Carbohydrate knowledge, beliefs, and intended practices, of endurance athletes who report exercise-associated gastrointestinal symptoms
This study aimed to explore carbohydrate (CHO) knowledge, beliefs, and intended practices of endurance athletes who experience exercise-associated gastrointestinal symptoms (Ex-GIS) compared to those without Ex-GIS. A validated online questionnaire was completed by endurance athletes (n = 201) participating in >60 min of exercise that present with Ex-GIS (n = 137) or without (n = 64). Descriptive statistics were used for parametric and non-parametric data with appropriate significance tests. Associations between categorical data were assessed by Chi-square analysis, and post-hoc Bonferroni tests were applied when significant. A content analysis of open-ended responses was grouped into themes, and quantitative statistics were applied. Participants included runners (n = 114, 57%), triathletes (n = 43, 21%) and non-running sports (n = 44, 21%) who participate in recreational competitive (n = 74, 37%), recreational non-competitive (n = 64, 32%), or competitive regional, national, or international levels (n = 63, 31%). Athletes correctly categorized CHO (x̄ = 92–95%) and non-CHO (x̄ = 88–90%) food and drink sources. On a Likert scale of 1 (strongly disagree) to 5 (strongly agree) athletes typically agree or strongly agree that consuming CHO around key training sessions and competitions enhances athletic performance [median = 4 (IQR, 4–5)], and they intend to consume more CHO around exercise [median = 3 (IQR, 2–3)]. No differences in beliefs and intentions were found among athletes with or without Ex-GIS. To enhance athletic performance, most endurance athletes intend to consume more CHO around exercise. Adequate knowledge of CHO-containing food sources was apparent; however, specific CHO ingestion practices remain to be verified
Do observed metallicity gradients of early-type galaxies support a hybrid formation scenario?
We measure radial gradients of the Mg2 index in 15 E-E/S0 and 14 S0 galaxies.
Our homogeneous data set covers a large range of internal stellar velocity
dispersions (2.0<logsigma<2.5) and Mg2 gradients (dMg2/dlogr/re* up to
-0.14mag/dex). We find for the first time, a noticeable lower boundary in the
relation between Mg2 gradient and sigma along the full range of sigma, which
may be populated by galaxies predominantly formed by monolithic collapse. At
high sigma, galaxies showing flatter gradients could represent objects which
suffered either important merging episodes or later gas accretion. These
processes contribute to the flattening of the metallicity gradients and their
increasing importance could define the distribution of the objects above the
boundary expected by the ``classical'' monolithic process. This result is in
marked contrast with previous works which found a correlation between
dMg2/dlogr/re* and sigma confined to the low mass galaxies, suggesting that
only galaxies below some limiting sigma were formed by collapse whereas the
massive ones by mergers. We show observational evidence that a hybrid scenario
could arise also among massive galaxies. Finally, we estimated d[Z/H] from Mg2
and Hbeta measurements and single stellar population models. The conclusions
remain the same, indicating that the results cannot be ascribed to age effects
on Mg2.Comment: 11 pages, 2 figures, to appear in ApJLetter
A new antitumoral Heteroarylaminothieno[3,2-b]pyridine derivative : its incorporation into liposomes and interaction with proteins monitored by fluorescence
Advance Article. 2014 Oct 16 [Epub ahead of print]The fluorescence properties of the new potent antitumoral methyl 3-amino-6-(benzo[d]thiazol-2-ylamino)thieno[3,2-b]pyridine-2-carboxylate in solution and when encapsulated in several different nanoliposome formulations were investigated. The compound exhibits very reasonable fluorescence quantum yields and a solvent sensitive emission in several polar and non-polar media, despite not being fluorescent in protic solvents.
Fluorescence anisotropy measurements of the compound incorporated in liposomes revealed that this thienopyridine derivative can be carried in the hydrophobic region of the lipid membrane. Liposome formulations including this antitumor compound are nanometric in size, with a diameter lower than 130 nm and generally low polydispersity, being promising for future drug delivery developments.
The interaction of the compound with bovine serum albumin (BSA) and the multidrug resistance protein MDR1 was monitored by FRET, the compound acting as energy acceptor. It was observed a lower interaction with MDR1 protein than with the native form of BSA, which is an important result regarding applications of this antitumoral drug.Foundation for the Science and Technology (FCT, Portugal),
FEDER/COMPETE and QREN for financial support to the
Research Centres, CFUM [Strategic Project PEst-
C/FIS/UI0607/2013 (FCOMP-01-0124-FEDER-022711) and
CQ/UM [Strategic Project PEst-C/QUI/UI0686/2013
(FCOMP-01-0124-FEDER-022716)] and n-STeP Project
NORTE-07-0124-FEDER-000039 supported by the
Operational Regional Programme of North of Portugal (ON.2).
FCT and POPH/QREN/FSE are acknowledged for the Post-
Doc. grant of R.C.C. (SFRH/BPD/68344/2010)
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