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1.
Data Brief ; 53: 110082, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38317725

RESUMO

A test station was designed and built to measure the thermal stratification (vertical thermal gradients) in a horizontal 150 L electric water heater storage device for different external environmental and user-emulating inputs, ambient temperature, inlet water temperature, water draw flow rate, thermostat temperature and heating coil active time. Stratification measurement consists of 66 temperature sensors that coarsely map three-dimensional temperature gradients within the horizontally configured heating device, under different operational conditions. Other significant temperatures such as inlet, outlet, ambient, thermostat feedback, and wall temperatures were also recorded. An ambient temperature control (climatic) chamber was built to emulate the environmental conditions. A custom-built controller was used to control thermal actuators, the power to the thermostat and the state of the outlet valve. In addition, it also acted as a data acquisition system, responsible for recording all relevant sensor data that was present in the system as well as the test station operating states. The dataset includes heating and thermostat control data and the corresponding thermal stratification profiles under static operating conditions (no water draw) at different ambient temperatures (20 °C, 30 °C, and 40 °C). Additionally, dynamic operating conditions (with water draw) are recorded, maintaining inlet water temperatures at approximately 10 °C and 30 °C. The dataset highlights thermal profiles with and without thermostat control and ambient cooling data without thermostat control. Existing research primarily focuses on vertically oriented water heaters, with limited attention to thermal modelling and data acquisition in horizontal configurations. This work provides valuable insights into the internal thermal dynamics of horizontally configured electric water heater storage devices, widely used worldwide.

2.
Rev Sci Instrum ; 89(10): 10F113, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30399895

RESUMO

The Aerogel Cherenkov Detector for Cygnus (ACD/C) is a time-dependent, x-ray spectral detector that uses SiO2 aerogels spanning an index of refraction (n = 1.02-1.07) corresponding to a 1.1-2.3 MeV x-ray energy threshold. The ACD/C was developed for pulsed power x-ray sources like Cygnus located at the Nevada National Site and Mercury located at the Naval Research Laboratory (NRL). Aerogels sit between the measurement capabilities of gas (>2 MeV) and solids such as fused silica (>0.3 MeV). The detector uses an aluminum converter to Compton scatter incoming x-rays and create relativistic electrons, which produce Cherenkov light in an aerogel or a fused silica medium. The ACD/C was fielded at the NRL when Mercury was tuned to produce up to 4.8 MeV endpoint bremsstrahlung. Despite a high radiation and electromagnetic interference background, the ACD/C was able to achieve high signal over noise across five aerogel densities and fused silica, including a signal to noise for a 1.1 MeV aerogel threshold. Previous experiments at Cygnus observed a signal that was comparable to the noise (1×) at the same threshold. The ACD/C observed time-resolved rise and fall times for different energy thresholds of the photon spectrum. Monte Carlo simulations of the ACD/C's aerogel response curves were folded with a simulation of Mercury's photon energy spectrum and agree within the error to the observed result.

3.
Sci Rep ; 7(1): 17631, 2017 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-29247246

RESUMO

Phytophthora cinnamomi is the causal agent of root rot, canker and dieback of thousands of plant species around the globe. This oomycete not only causes severe economic losses but also threatens natural ecosystems. In South Africa, P. cinnamomi affects eucalyptus, avocado, macadamia and indigenous fynbos. Despite being one of the most important plant pathogens with a global distribution, little information is available regarding origin, invasion history and population biology. This is partly due to the limited number of molecular markers available for studying P. cinnamomi. Using available genome sequences for three isolates of P. cinnamomi, sixteen polymorphic microsatellite markers were developed as a set of multiplexable markers for both PCR and Gene Scan assays. The application of these markers on P. cinnamomi populations from avocado production areas in South Africa revealed that they were all polymorphic in these populations. The markers developed in this study represent a valuable resource for studying the population biology and movement of P. cinnamomi and will aid in the understanding of the origin and invasion history of this important species.


Assuntos
Repetições de Microssatélites/genética , Persea/parasitologia , Phytophthora/genética , Doenças das Plantas/parasitologia , Raízes de Plantas/parasitologia , Marcadores Genéticos/genética , Genótipo , Phytophthora/isolamento & purificação , África do Sul
4.
Rev Sci Instrum ; 87(11): 11D407, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27910685

RESUMO

We have shown that Zeeman splitting of the sodium (Na) D-lines at 5890 and 5896 Å can be used to measure the magnetic field (B-field) produced in high current pulsed power experiments. We have measured the B-field next to a return current conductor in a hybrid X-pinch experiment near a peak current of about 500 kA. Na is deposited on the conductor and then is desorbed and excited by radiation from the hybrid X-pinch. The D-line emission spectrum implies B-fields of about 20 T with a return current post of 4 mm diameter or up to 120 T with a return current wire of 0.455 mm diameter. These measurements were consistent or lower than the expected B-field, thereby showing that basic Zeeman splitting can be used to measure the B-field in a pulsed-power-driven high-energy-density (HED) plasma experiment. We hope to extend these measurement techniques using suitable ionized species to measurements within HED plasmas.

5.
Rev Sci Instrum ; 87(10): 103506, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27802687

RESUMO

We have shown that the Zeeman splitting of the sodium (Na) D-lines at 5890 Å and 5896 Å can be used to measure the magnetic field produced by the current flowing in an exploding wire prior to wire explosion. After wire explosion, the lines in question are either not visible in the strong continuum from the exploding wire plasma, or too broad to measure the magnetic field by methods discussed in this paper. We have determined magnetic fields in the range 10-20 T, which lies between the small field and Paschen-Back regimes for the Na D-lines, over a period of about 70 ns on a 10 kA peak current machine. The Na source is evaporated drops of water with a 0.171 M NaCl solution deposited on the wire. The Na desorbs from the wire as it heats up, and the excited vapor atoms are seen in emission lines. The measured magnetic field, determined by the Zeeman splitting of these emission lines, estimates the average radial location of the emitting Na vapor as a function of time under the assumption the current flows only in the wire during the time of the measurement.

6.
Plant Dis ; 97(8): 1012-1017, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30722481

RESUMO

Phytophthora cinnamomi causes Phytophthora root rot (PRR) in avocado (Persea americana), an important disease that causes severe economic losses to the avocado industry globally. To date, no PRR-resistant avocado rootstock variety has been discovered, although certain rootstock varieties have been shown to be more tolerant than others. In this study, we developed an accurate, low cost assay for in planta quantification of P. cinnamomi to evaluate disease tolerance. A nested real-time polymerase chain reaction assay was developed to sensitively detect pathogen DNA in plant tissues. Root samples from a highly tolerant (Dusa) and less tolerant (R0.12) rootstock were collected at 0, 3, 7, 14, and 21 days after inoculation with P. cinnamomi and used for pathogen quantification. Nested primers developed in this study were specific and sensitive and could detect P. cinnamomi in root tissues. The amount of P. cinnamomi quantified in roots was significantly higher in the less-tolerant R0.12 plants when compared with the highly tolerant Dusa plants at all time points. This study has confirmed the known status of disease tolerance of Dusa and R0.12 avocado rootstocks in a quantitative manner and provides a reliable molecular tool to assist with industry breeding programs for the selection of PRR-resistant avocado rootstock varieties.

7.
Phys Rev Lett ; 92(13): 137002, 2004 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-15089639

RESUMO

The bulk-representative low-energy spectrum of Sr2RuO4 can be directly measured by angle-resolved photoemission. We find that the quasiparticle spectral line shape of Sr2RuO4 is sensitive to both temperature and momentum. Along the (0,0)-(pi,0) direction, both gamma and beta bands develop a sharp quasiparticle peak near k(F) at low temperatures, but as the temperature increases the spectra quickly lose coherent weight and become broad backgrounds above approximately 130 K, which is the metal-nonmetal crossover temperature, T(M), in the c-axis resistivity. However, spectra along the (0,0)-(pi,pi) direction evolve smoothly across T(M). A simple transport model can describe both in-plane and c-axis resistivity in terms of the quasiparticle line shape. Comparisons are also made to the cuprates, with implications for two dimensionality, magnetic fluctuations, and superconductivity.

10.
Phys Rev Lett ; 88(22): 226803, 2002 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-12059443

RESUMO

We show theoretically that in quantum wells subjected to a strong magnetic field the intersubband current peaks at magnetic field values, which reveal the underlying specific intersubband scattering mechanism. We have designed and grown a superlattice structure in which such current oscillations are clearly visible, and in which the transition from the purely single-electron to the mixed single- and two-electron scattering regimes can be observed by tuning the applied voltage bias. The measurements were conducted in ultrahigh magnetic fields (up to 45 T) to obtain the full spectrum of the current oscillations.

11.
Phys Rev Lett ; 87(22): 227001, 2001 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-11736418

RESUMO

We study the doping and temperature dependence of the single-particle coherent weight, z(A), for high- T(c) superconductors Bi(2)Sr(2)CaCu(2)O(8+x) using angle-resolved photoemission. We find that at low temperatures the coherent weight z(A) at (pi,0) is proportional to the carrier concentration x and that the temperature dependence of z(A) is similar to that of the c-axis superfluid density. We show that, for a wide range of carrier concentration, the superconducting transition temperature scales with the product of the low-temperature coherent weight and the maximum superconducting gap.

12.
Z Arztl Fortbild Qualitatssich ; 95(8): 531-3, 2001 Aug.
Artigo em Alemão | MEDLINE | ID: mdl-11575135

RESUMO

New ways of cooperation between doctors and representatives of patients are followed with the help of the patients' forum which was founded on the initiative of the German Medical Association. Members of the German Association 'Help for the Handicapped People', the 'Forum of the Chronic Ill and Handicapped People' of the 'Equal Charitable Organisation' (Paritätischer Wohlfahrtsverband), the 'German Association of Self-Help Groups' as well as representatives of the committees and the management of the German Medical Association and the National Association of Statutory Health Insurance Physicians form the patients' forum. The major aim of this cooperation is to discuss the possibilities and the ways to improve the quality in health care. A direct participation of patients' representatives is for the moment planned in the evaluation of the quality of medical information for the lay public. In cooperation with the Agency for Quality in Medicine--a joint institution of the German Medical Association and the National Association of Statutory Health Insurance Physicians--the quality of information on health care that is published in the internet should be examined. The patients' information service which was developed by the Agency for Quality in Medicine and is found under www.patienten-information.de is the basis for this examination.


Assuntos
Atenção à Saúde/normas , Pessoas com Deficiência , Educação em Saúde/normas , Relações Interinstitucionais , Defesa do Paciente , Poder Psicológico , Grupos de Autoajuda , Sociedades Médicas , Instituições Filantrópicas de Saúde , Doença Crônica , Alemanha , Humanos , Garantia da Qualidade dos Cuidados de Saúde
13.
Nature ; 413(6853): 282-5, 2001 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-11565024

RESUMO

The parent compounds of the copper oxide high-transition-temperature (high-Tc) superconductors are unusual insulators (so-called Mott insulators). Superconductivity arises when they are 'doped' away from stoichiometry. For the compound Bi2Sr2CaCu2O8+x, doping is achieved by adding extra oxygen atoms, which introduce positive charge carriers ('holes') into the CuO2 planes where the superconductivity is believed to originate. Aside from providing the charge carriers, the role of the oxygen dopants is not well understood, nor is it clear how the charge carriers are distributed on the planes. Many models of high-Tc superconductivity accordingly assume that the introduced carriers are distributed uniformly, leading to an electronically homogeneous system as in ordinary metals. Here we report the presence of an electronic inhomogeneity in Bi2Sr2CaCu2O8+x, on the basis of observations using scanning tunnelling microscopy and spectroscopy. The inhomogeneity is manifested as spatial variations in both the local density of states spectrum and the superconducting energy gap. These variations are correlated spatially and vary on the surprisingly short length scale of approximately 14 A. Our analysis suggests that this inhomogeneity is a consequence of proximity to a Mott insulator resulting in poor screening of the charge potentials associated with the oxygen ions left in the BiO plane after doping, and is indicative of the local nature of the superconducting state.

14.
Environ Monit Assess ; 69(1): 1-15, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11393541

RESUMO

This article presents results from the particulate monitoring campaign conducted at Qalabotjha in South Africa during the winter of 1997. Combustion of D-grade domestic coal and low-smoke fuels were compared in a residential neighborhood to evaluate the extent of air quality improvement by switching household cooking and heating fuels. Comparisons are drawn between the gravimetric results from the two types of filter substrates (Teflon-membrane and quartz-fiber) as well as between the integrated and continuous samplers. It is demonstrated that the quartz-fiber filters reported 5 to 10% greater particulate mass than the Teflon-membrane filters, mainly due to the adsorption of organic gases onto the quartz-fiber filters. Due to heating of sampling stream to 50 degrees C in the TEOM continuous sampler and the high volatile content of the samples, approximately 15% of the particulate mass was lost during sampling. The USEPA 24-hr PM2.5 and PM10 National Ambient Air Quality Standards (NAAQS) of 65 microg m(-3) and 150 microg m(-3), respectively, were exceeded on several occasions during the 30-day field campaign. Average PM concentrations are highest when D-grade domestic coal was used, and lowest between day 11 and day 20 of the experiment when a majority of the low-smoke fuels were phased in. Source impacts from residential coal combustion are also found to be influenced by changes in meteorology, especially wind velocity. PM2.5 and PM10 mass, elements, water-soluble cations (sodium, potassium, and ammonium), anions (chloride, nitrate, and sulfate), as well as organic and elemental carbon were measured on 15 selected days during the field campaign. PM2.5 constituted more than 85% of PM10 at three Qalabotjha residential sites, and more than 70% of PM10 at the gradient site in the adjacent community of Villiers. Carbonaceous aerosol is by far the most abundant component, accounting for more than half of PM mass at the three Qalabotjha sites, and for more than a third of PM mass at the gradient site. Secondary aerosols such as sulfate, nitrate, and ammonium are also significant, constituting 8 to 12% of PM mass at the three Qalabotjha sites and 15 to 20% at the Villiers gradient site.


Assuntos
Poluição do Ar/análise , Poluição do Ar/prevenção & controle , Carvão Mineral , Monitoramento Ambiental , Aerossóis , Culinária , Habitação , Humanos , Incineração , Tamanho da Partícula
15.
Ann Biomed Eng ; 28(6): 629-40, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10983709

RESUMO

The aim of this work is to reproduce the experimentally measured linear dependence of cardiac muscle oxygen consumption on stress-strain area using a model, composed of a three-state Huxley-type model for cross-bridge interaction and a phenomenological model of Ca2+-induced activation. By selecting particular cross-bridge cycling rate constants and modifying the cross-bridge activation model, we replicated the linear dependence between oxygen consumption and stress-strain area together with other important mechanical properties of cardiac muscle such as developed stress dependence on the sarcomere length and force-velocity relationship. The model predicts that (1) the amount of the "passenger" cross bridges, i.e., cross bridges that detach without hydrolyzing ATP molecule, is relatively small and (2) ATP consumption rate profile within a beat and the amount of the passenger cross bridges depend on the contraction protocol.


Assuntos
Metabolismo Energético/fisiologia , Modelos Lineares , Modelos Cardiovasculares , Contração Miocárdica/fisiologia , Miocárdio/metabolismo , Análise Numérica Assistida por Computador , Consumo de Oxigênio/fisiologia , Actomiosina/fisiologia , Trifosfato de Adenosina/metabolismo , Metabolismo Basal , Cálcio/metabolismo , Elasticidade , Análise de Elementos Finitos , Hidrólise , Contração Isotônica/fisiologia , Valor Preditivo dos Testes , Sarcômeros/fisiologia , Estresse Mecânico , Ciclização de Substratos , Termodinâmica
16.
Brief Bioinform ; 1(1): 93-9, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11466977

RESUMO

The availability of large expressed sequence tag (EST) databases has led to a revolution in the way new genes are identified. Mining of these databases using known protein sequences as queries is a powerful technique for discovering orthologous and paralogous genes. The scientist is often confronted, however, by an enormous amount of search output owing to the inherent redundancy of EST data. In addition, high search sensitivity often cannot be achieved using only a single member of a protein superfamily as a query. In this paper a technique for addressing both of these issues is described. Assembled EST databases are queried with every member of a protein superfamily, the results are integrated and false positives are pruned from the set. The result is a set of assemblies enriched in members of the protein superfamily under consideration. The technique is applied to the G protein-coupled receptor (GPCR) superfamily in the construction of a GPCR Resource. A novel full-length human GPCR identified from the GPCR Resource is presented, illustrating the utility of the method.


Assuntos
Etiquetas de Sequências Expressas , Proteínas/química , Proteínas/genética , Receptores de Superfície Celular/química , Receptores de Superfície Celular/genética , Sequência de Aminoácidos , Animais , Bases de Dados Factuais , Proteínas de Ligação ao GTP/metabolismo , Humanos , Dados de Sequência Molecular , Sensibilidade e Especificidade
17.
Z Gerontol Geriatr ; 30(2): 85-8, 1997.
Artigo em Alemão | MEDLINE | ID: mdl-9229538

RESUMO

Due to the importance of geriatrics which has been generally accepted in the inpatient medical care for many years, geriatrics has now been included into the amended Model Regulations of Postgraduate Medical Training (novellierte Muster-Weiter-bildungsordnung) in the form of the optional postgraduate training "clinical geriatrics". Thus geriatrics has the chance of being broadly accepted and standing the test in clinic and practice where our colleagues are working.


Assuntos
Educação Médica Continuada/tendências , Educação de Pós-Graduação em Medicina/tendências , Geriatria/educação , Idoso , Currículo/tendências , Previsões , Alemanha , Humanos , Equipe de Assistência ao Paciente/tendências
18.
Protein Eng ; 10(1): 1-6, 1997 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9051728

RESUMO

We have developed a new method for the identification of signal peptides and their cleavage sites based on neural networks trained on separate sets of prokaryotic and eukaryotic sequence. The method performs significantly better than previous prediction schemes and can easily be applied on genome-wide data sets. Discrimination between cleaved signal peptides and uncleaved N-terminal signal-anchor sequences is also possible, though with lower precision. Predictions can be made on a publicly available WWW server.


Assuntos
Sequência de Aminoácidos/fisiologia , Células Eucarióticas/química , Redes Neurais de Computação , Células Procarióticas/química , Sinais Direcionadores de Proteínas/química , Algoritmos , Receptores ErbB/química , Humanos , Dados de Sequência Molecular , Processamento de Proteína Pós-Traducional/fisiologia , Relação Estrutura-Atividade
19.
Int J Neural Syst ; 8(5-6): 581-99, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-10065837

RESUMO

We have developed a new method for the identification of signal peptides and their cleavage sites based on neural networks trained on separate sets of prokaryotic and eukaryotic sequences. The method performs significantly better than previous prediction schemes, and can easily be applied to genome-wide data sets. Discrimination between cleaved signal peptides and uncleaved N-terminal signal-anchor sequences is also possible, though with lower precision. Predictions can be made on a publicly available WWW server: http://www.cbs.dtu.dk/services/SignalP/.


Assuntos
Células Eucarióticas/fisiologia , Redes Neurais de Computação , Células Procarióticas/fisiologia , Sinais Direcionadores de Proteínas/química , Algoritmos , Sequência de Aminoácidos , Sistemas Computacionais , Citoplasma/química , Bases de Dados Factuais , Genoma , Haemophilus/genética , Humanos , Dados de Sequência Molecular , Proteínas Nucleares/química
20.
S Afr J Surg ; 34(4): 194-6, 1996 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9015946

RESUMO

The management of soft-tissue defects of the hand with exposed bone and tendons may be difficult. The posterior interosseous flap is a fasciocutaneous island from the dorsal forearm, based on the posterior interosseous vessels. We have used this flap as a one-stage procedure to cover soft-tissue defects of the hand in 6 patients. It provides excellent cover without sacrificing a major blood vessel such as the radial artery. Although the vascular anatomy of the flap is normally consistent, variations exist. This prevented elevation of 1 of the flaps in our series.


Assuntos
Traumatismos da Mão/cirurgia , Retalhos Cirúrgicos , Antebraço/irrigação sanguínea , Antebraço/cirurgia , Humanos , Retalhos Cirúrgicos/métodos , Fatores de Tempo , Cicatrização
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