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1.
Phys Rev Lett ; 118(7): 073601, 2017 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-28256845

RESUMO

We present a transportable optical clock (TOC) with ^{87}Sr. Its complete characterization against a stationary lattice clock resulted in a systematic uncertainty of 7.4×10^{-17}, which is currently limited by the statistics of the determination of the residual lattice light shift, and an instability of 1.3×10^{-15}/sqrt[τ] with an averaging time τ in seconds. Measurements confirm that the systematic uncertainty can be reduced to below the design goal of 1×10^{-17}. To our knowledge, these are the best uncertainties and instabilities reported for any transportable clock to date. For autonomous operation, the TOC has been installed in an air-conditioned car trailer. It is suitable for chronometric leveling with submeter resolution as well as for intercontinental cross-linking of optical clocks, which is essential for a redefinition of the International System of Units (SI) second. In addition, the TOC will be used for high precision experiments for fundamental science that are commonly tied to precise frequency measurements and its development is an important step to space-borne optical clocks.

2.
Phys Rev Lett ; 118(26): 263202, 2017 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-28707932

RESUMO

We report on two ultrastable lasers each stabilized to independent silicon Fabry-Pérot cavities operated at 124 K. The fractional frequency instability of each laser is completely determined by the fundamental thermal Brownian noise of the mirror coatings with a flicker noise floor of 4×10^{-17} for integration times between 0.8 s and a few tens of seconds. We rigorously treat the notorious divergences encountered with the associated flicker frequency noise and derive methods to relate this noise to observable and practically relevant linewidths and coherence times. The individual laser linewidth obtained from the phase noise spectrum or the direct beat note between the two lasers can be as small as 5 mHz at 194 THz. From the measured phase evolution between the two laser fields we derive usable phase coherence times for different applications of 11 to 55 s.

3.
Nervenarzt ; 88(7): 802-810, 2017 Jul.
Artigo em Alemão | MEDLINE | ID: mdl-27981375

RESUMO

STUDY OBJECTIVE: A simple instrument to record case-related coercive measures was tested as part of a pilot project of the German Association for Psychiatry, Psychotherapy and Psychosomatics (DGPPN). METHODS: To assess coercive measures data were collected for 3 months in 8 German hospitals for psychiatry and psychotherapy. The type of measures used, the main diagnosis and the legal basis for the coercive measures were documented. RESULTS: In the sample studied, coercive measures were applied in 8% of cases. Coercive measures were most commonly used in patients with a schizophrenic disorder. The principle of justifiable necessity according to § 34 of the German Penal Code was used particularly often as the legal basis for justifying the coercive measures. CONCLUSION: Suitable measurement instruments and reliable data that enable the learning of best practices represent the basis for a reduction of coercive measures.


Assuntos
Coerção , Hospitais Psiquiátricos , Transtornos Mentais/psicologia , Transtornos Mentais/terapia , Psicometria/estatística & dados numéricos , Psicoterapia , Garantia da Qualidade dos Cuidados de Saúde/estatística & dados numéricos , Estudos Transversais , Alemanha , Hospitais Psiquiátricos/legislação & jurisprudência , Humanos , Transtornos Mentais/epidemiologia , Isolamento de Pacientes/legislação & jurisprudência , Projetos Piloto , Psicoterapia/legislação & jurisprudência , Garantia da Qualidade dos Cuidados de Saúde/legislação & jurisprudência , Restrição Física/legislação & jurisprudência , Esquizofrenia/epidemiologia , Esquizofrenia/terapia , Psicologia do Esquizofrênico , Sociedades Médicas , Transtornos Relacionados ao Uso de Substâncias/epidemiologia , Transtornos Relacionados ao Uso de Substâncias/terapia
4.
Nervenarzt ; 87(7): 753-9, 2016 Jul.
Artigo em Alemão | MEDLINE | ID: mdl-26556095

RESUMO

BACKGROUND: The legislation requires all scientific societies in the field of inpatient psychiatric and psychosomatic healthcare to survey and assess the effects and financial incentives of the new flat rate day-based remuneration system in psychiatric and psychosomatic facilities (PEPP system). As day-based remuneration systems may be an incentive to extend treatment, it is necessary to measure and analyze the future development of the number of cases and the duration of treatment. OBJECTIVES: This article surveys admission and discharge decisions of psychiatric and psychosomatic facilities. The distribution of admissions and discharges throughout the days of the week were analyzed to search for evidence of a systematic extension of treatment over the weekend. MATERIAL AND METHODS: The analysis is based on data from the Versorgungsrelevante Indikatoren in der Psychiatrie und Psychosomatik (VIPP, treatment-relevant indicators in psychiatry and psychosomatics) project database, which contains routine data from psychiatric and psychosomatic facilities. On this basis the distributions of admissions and discharges throughout the days of the week were analyzed on aggregate and diagnosis-specific levels. RESULTS: Patients were mostly admitted to hospitals within the first 3 weekdays. The discharge mostly took place on Fridays and not as a financial incentive on Mondays. Regarding the patient length of stay a 7-day cycle can be observed, which may indicate the importance of medical and organizational factors in discharge decisions. CONCLUSION: The results do not show evidence for a systematic extension of treatment over the weekend. Over the next years it will be important to observe the development of the duration of treatment and the number of cases to assess the influence of the economic incentives of the PEPP system on the utilization of psychiatric and psychosomatic healthcare.


Assuntos
Hospitais Psiquiátricos/estatística & dados numéricos , Tempo de Internação/estatística & dados numéricos , Admissão do Paciente/estatística & dados numéricos , Alta do Paciente/estatística & dados numéricos , Revisão da Utilização de Recursos de Saúde , Carga de Trabalho/estatística & dados numéricos , Tomada de Decisão Clínica , Bases de Dados Factuais , Alemanha/epidemiologia , Humanos
5.
Eur Cell Mater ; 29: 70-80; discujssion 80-1, 2015 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-25579755

RESUMO

Degeneration of the intervertebral disc (IVD) is a progressive and chronic process, and the high incidence of discogenic disorders calls for new therapeutic approaches, such as cell-based therapies using three dimensional cultures and mesenchymal stem cells (MSC), which can differentiate to chondrogenic- and IVD-lineages. Here, we investigated the growth and differentiation of human MSC culture on biodegradable collagen scaffolds in order to obtain an injectable suspension. Commercially available wound dressings were downsized to dimensions between 100 and 1500 µm and seeded with freshly isolated or early passages MSC. Proliferation rate and chondrogenic differentiation potential was tested at oxygenation levels of 2%, 5%, 10% and 21% in static and dynamic cultures. Evaluation methods included cell viability test, disc marker genes expression (aggrecan, collagen type I and type II), histological detection of proteoglycans and immunohistochemical analysis. On microcarriers, freshly isolated MSC had lower proliferation rate and chondrogenic differentiation potential compared with early passages MSC. Proliferation of MSC was significantly increased 1.7-fold at 5% oxygen level and in combination with dynamic culture was further increased to 2.3-fold, with respect to normoxia. Chondrogenesis was positively affected by 2% and 5% hypoxia, as shown by increased transcription levels and protein expression of collagen type II and proteoglycan accumulation in static cultures, while it was inhibited in dynamic cultures. Collagen type I and aggrecan expression were not affected by hypoxia. In conclusion, collagen based microcarriers are a suitable support for in vitro MSC growth and chondrogenesis especially when cultured at 5% oxygen level.


Assuntos
Cartilagem/citologia , Degeneração do Disco Intervertebral/terapia , Células-Tronco Mesenquimais/citologia , Engenharia Tecidual/métodos , Adulto , Agrecanas/genética , Agrecanas/metabolismo , Cartilagem/metabolismo , Técnicas de Cultura de Células/instrumentação , Técnicas de Cultura de Células/métodos , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Condrócitos/citologia , Condrócitos/metabolismo , Condrogênese/efeitos dos fármacos , Colágeno Tipo I/química , Colágeno Tipo I/genética , Colágeno Tipo I/metabolismo , Colágeno Tipo II/genética , Colágeno Tipo II/metabolismo , Relação Dose-Resposta a Droga , Expressão Gênica/efeitos dos fármacos , Humanos , Imuno-Histoquímica , Injeções , Transplante de Células-Tronco Mesenquimais/instrumentação , Transplante de Células-Tronco Mesenquimais/métodos , Células-Tronco Mesenquimais/metabolismo , Pessoa de Meia-Idade , Oxigênio/farmacologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Alicerces Teciduais/química
6.
Emerg Med J ; 32(5): 409-11, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25714107

RESUMO

OBJECTIVE: The increasing prevalence of multidrug resistant bacteria is a problem in the inpatient care setting, and in the emergency care system. The aim of this observational, cross-sectional study was to evaluate the prevalence of pathogens on well-defined surfaces in German ambulances that have been designated as 'ready for service'. METHODS: After informed consent was obtained, ambulance surfaces were sampled with agar plates for microbiological examination during an unannounced visit. A standardised questionnaire was used to obtain information regarding the disinfection protocols used at each rescue station. RESULTS: Methicillin resistant staphylococcus aureus contamination was present in 18 sampling surfaces from 11 out of 150 ambulance vehicles (7%) that were designated as ready for service. Contact surfaces directly surrounding patients or staff were most frequently contaminated with pathogens. However, bacterial contamination was not related to annual missions, methods or frequency of disinfection. CONCLUSIONS: In accordance with previous studies, disinfection and cleaning of areas with direct contact to patients or staff seem to be the most challenging. This should also be reflected in disinfection guidelines and the related continuing education.


Assuntos
Ambulâncias , Bactérias/isolamento & purificação , Fungos/isolamento & purificação , Ágar , Infecção Hospitalar/prevenção & controle , Estudos Transversais , Meios de Cultura , Contaminação de Equipamentos , Humanos , Prevalência
7.
Nervenarzt ; 86(7): 866-71, 2015 Jul.
Artigo em Alemão | MEDLINE | ID: mdl-25591753

RESUMO

People with severe mental disorders have a reduction in life expectancy of 13-30 % compared with the general population. This severe disadvantage is primarily due to an increased prevalence of cardiac and metabolic disorders, especially coronary heart disease (CHD) and type 2 diabetes mellitus and are the result of untoward health behavior characterized by smoking, low levels of physical activity and unhealthy dietary habits. Obesity, arterial hypertension and lipid disorders are also associated with this behavior and further increase the risk of CHD and type 2 diabetes. Thus, people with mental disorders constitute a population with a high risk of cardiovascular events. Appropriate measures for prevention and therapy are urgently indicated but rarely applied. This article presents new organizational structures to overcome this deficit with a prevention manager playing a central role in organizing and applying preventive and therapeutic care. Results from cardiology and diabetic medicine have shown the effectiveness of pooling this responsibility. The measure has the potential to reduce the increased mortality of people with severe mental disorders.


Assuntos
Cardiopatias/prevenção & controle , Transtornos Mentais/terapia , Doenças Metabólicas/prevenção & controle , Administração dos Cuidados ao Paciente/organização & administração , Prevenção Primária/organização & administração , Gestão de Riscos/organização & administração , Alemanha , Cardiopatias/complicações , Cardiopatias/diagnóstico , Humanos , Transtornos Mentais/complicações , Transtornos Mentais/diagnóstico , Doenças Metabólicas/complicações , Doenças Metabólicas/diagnóstico , Modelos Organizacionais , Taxa de Sobrevida
8.
Phys Rev Lett ; 112(25): 250404, 2014 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-25014797

RESUMO

We observe two consecutive heteronuclear Efimov resonances in an ultracold Li-Cs mixture by measuring three-body loss coefficients as a function of magnetic field near a Feshbach resonance. The first resonance is detected at a scattering length of a_((0))=-320(10)a_((0)), corresponding to ∼7(∼3) times the Li-Cs (Cs-Cs) van der Waals range. The second resonance appears at 5.8(1.0)a_((0)), close to the unitarity-limited regime at the sample temperature of 450 nK. Indication of a third resonance is found in the atom loss spectra. The scaling of the resonance positions is close to the predicted universal scaling value of 4.9 for zero temperature. Deviations from universality might be caused by finite-range and temperature effects, as well as magnetic field-dependent Cs-Cs interactions.

9.
Int J Geriatr Psychiatry ; 29(3): 245-52, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23804458

RESUMO

OBJECTIVE: Loneliness has a deep impact on quality of life in older people. Findings on sex-specific differences on the experience of loneliness remain sparse. This study compared the intensity of and factors associated with loneliness between men and women. METHODS: Analyses are based on the 2008/2009 data of the KORA-Age Study, comprising 4127 participants in the age range of 64-94 years. An age-stratified random subsample of 1079 subjects participated in a face-to-face interview. Loneliness was measured by using a short German version of the UCLA-Loneliness-Scale (12 items, Likert scaled, ranging from 0 to 36 points). Multiple logistic regression analysis was conducted to analyze the associations of socio-demographic, physical, and psychological factors with loneliness. RESULTS: The mean level of loneliness did not significantly differ between men (17.0 ± 4.5) and women (17.5 ± 5.1). However, among the oldest old (≥85 years), loneliness was higher in women (p value = 0.047). Depression, low satisfaction with life, and low resilience were associated significantly with loneliness, which was more pronounced in men. Living alone was not associated with loneliness, whereas lower social network was associated with a three time higher risk for feeling lonely in both men and women. CONCLUSIONS: The extent of loneliness was equally distributed between men and women, although women were more disadvantaged regarding living arrangements as well as physical and mental health. However, loneliness was stronger associated with adverse mental health conditions in men. These findings should be considered when developing intervention strategies to reduce loneliness.


Assuntos
Solidão/psicologia , Idoso , Idoso de 80 Anos ou mais , Transtornos Cognitivos/psicologia , Depressão/psicologia , Pessoas com Deficiência/psicologia , Feminino , Alemanha , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Qualidade de Vida/psicologia , Fatores Sexuais , Rede Social , Inquéritos e Questionários
10.
Fortschr Neurol Psychiatr ; 82(2): 84-92, 2014 Feb.
Artigo em Alemão | MEDLINE | ID: mdl-24519191

RESUMO

RESEARCH QUESTION: The aim of this study is to show that Friedrich Schiller (1759 - 1805) was very early in life inclined towards psychosomatic interactions. MATERIAL AND METHODS: An analysis of the secondary literature since the death of Friedrich Schiller for the subjects "Friedrich Schiller" and "psychosomatics" was undertaken. RESULTS: Already during his medical studies at the "Hohe Karlsschule" in Stuttgart (Germany) Schiller studied very intensively psychosomatic issues on account of the disease of another student, Joseph Frédéric Grammont, and included the topic in his three theses. Not inclined to practical work as a physician, there are many psychosomatic thoughts and medical concepts in his writings, especially in the play "Die Räuber" (1781) and in "Don Carlos, Infant von Spanien" (1787). Towards the then upcoming topic mesmerism he remained very sceptic. In coping with his own illness there are many psychosomatic aspects, too. Despite his own severe somatic illness he could cope with pain and emphasised in his writings the importance of the freedom of anxiety before death.


Assuntos
Medicina Psicossomática/história , Ansiedade/psicologia , Alemanha , História do Século XVIII , História do Século XIX , Hipnose , Dor/psicologia
11.
Vet Pathol ; 50(2): 256-9, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22688588

RESUMO

Peritonitis due to infections with green algae was diagnosed at slaughter (in Texas and South Dakota) in 2 cows. One cow also had a generalized lymphadenitis. The intralesional green algae were histologically similar to those previously associated with bovine lymphadenitis. Amplified and sequenced algal ITS2 genes had higher homology with the genus Scenedesmus than with Chlorella.


Assuntos
Doenças dos Bovinos/microbiologia , Doenças dos Bovinos/patologia , Clorófitas/genética , Linfadenite/veterinária , Peritonite/veterinária , Proteínas de Algas/genética , Animais , Sequência de Bases , Bovinos , Eletroforese em Gel de Ágar/veterinária , Feminino , Linfadenite/microbiologia , Linfadenite/patologia , Microscopia Eletrônica de Transmissão/veterinária , Técnicas de Diagnóstico Molecular/veterinária , Dados de Sequência Molecular , Peritonite/microbiologia , Peritonite/patologia , Reação em Cadeia da Polimerase/veterinária , Análise de Sequência de DNA , Homologia de Sequência , South Dakota , Texas
12.
Vet Pathol ; 49(2): 288-91, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21825310

RESUMO

Four young broiler chickens affected by multiple melanotic tumors are described. Grossly, there were multiple tumors composed of melanocytes within the skin, skeletal muscle, and multiple visceral organs. Tumors ranged from flattened macules to masses that extensively replaced viscera. Microscopically, melanocytes were often well pigmented, and while there was moderate nuclear anisokaryosis, mitotic rates were low. Immunohistochemical staining of some melanomas with antibodies to S100 proteins, Melan-A, vimentin, or neuron-specific enolase after bleaching of tumor cells with potassium permanganate revealed lack of immunostaining of tumor cells with antibodies to S100, strong positive staining of tumor cells for neuron-specific enolase, moderate staining with antibodies to vimentin, and faint staining for Melan-A. Only neuron-specific enolase staining was evident in unbleached tumor cells. Attempts to identify exogenous avian leukosis viruses in these tumors were unsuccessful.


Assuntos
Galinhas , Melanoma/veterinária , Doenças das Aves Domésticas/patologia , Neoplasias Cutâneas/veterinária , Animais , Vírus da Leucose Aviária/isolamento & purificação , Imuno-Histoquímica/veterinária , Antígeno MART-1/análise , Antígeno MART-1/imunologia , Melanócitos/patologia , Melanoma/metabolismo , Melanoma/patologia , Melanossomas/patologia , Índice Mitótico/veterinária , Fosfopiruvato Hidratase/análise , Fosfopiruvato Hidratase/imunologia , Pigmentação , Doenças das Aves Domésticas/metabolismo , Proteínas S100/análise , Proteínas S100/imunologia , Pele/patologia , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/patologia , Vimentina/análise , Vimentina/imunologia
13.
Nat Commun ; 13(1): 212, 2022 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-35017500

RESUMO

Ultrastable lasers are essential tools in optical frequency metrology enabling unprecedented measurement precision that impacts on fields such as atomic timekeeping, tests of fundamental physics, and geodesy. To characterise an ultrastable laser it needs to be compared with a laser of similar performance, but a suitable system may not be available locally. Here, we report a comparison of two geographically separated lasers, over the longest ever reported metrological optical fibre link network, measuring 2220 km in length, at a state-of-the-art fractional-frequency instability of 7 × 10-17 for averaging times between 30 s and 200 s. The measurements also allow the short-term instability of the complete optical fibre link network to be directly observed without using a loop-back fibre. Based on the characterisation of the noise in the lasers and optical fibre link network over different timescales, we investigate the potential for disseminating ultrastable light to improve the performance of remote optical clocks.

14.
Brain Behav Immun ; 25(8): 1701-7, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21756997

RESUMO

INTRODUCTION: Depressed individuals not only suffer from chronic low grade inflammation, but also exhibit an inflammatory hyper-responsiveness to acute stress. We investigate whether chronic stress also induces an exaggerated inflammatory response in individuals with increased depression features. As model for chronic stress, social isolation was chosen. METHODS: Interleukin (IL)-6 and hs-CRP levels were assessed in 1547 subjects (847 men and 700 women), derived from the population-based MONICA/KORA study. Standardized questionnaires were used to assess depressed mood (depression and exhaustion subscale) and social isolation (social network index). The relationship between the two inflammatory markers, social isolation and depressed mood was examined taking into account interactions social isolation × depressed mood using multivariable linear regression models, adjusted for age, BMI, smoking, alcohol, and physical activity. Analyses were performed in men and women separately. RESULTS: We observed a significant interaction between depressed mood and social isolation regarding IL-6 and hs-CRP, respectively in men (p-value=0.02 for IL-6 and <0.01 for hs-CRP), evidencing a substantial synergistic effect of social isolation, and depressed mood on inflammatory responses. Furthermore, depressed and socially isolated men had highly significantly elevated IL-6 levels (geometric mean: 3.76 vs. 1.92 pg/ml, p-value <0.01) and heightened hs-CRP levels (geometric mean: 2.01 vs. 1.39 mg/l, p=0.08) in comparison with non-depressed and socially integrated men. In women, no significant associations were seen. CONCLUSION: The interaction of depressed mood and social isolation elicits a substantial synergistic impact on inflammatory markers in men, but not in depressed women.


Assuntos
Biomarcadores/metabolismo , Depressão/metabolismo , Inflamação/metabolismo , Isolamento Social/psicologia , Afeto , Idoso , Proteína C-Reativa/metabolismo , Doença Crônica , Feminino , Humanos , Interleucina-6/metabolismo , Modelos Lineares , Masculino , Pessoa de Meia-Idade , População , Caracteres Sexuais , Meio Social , Estresse Psicológico/metabolismo , Estresse Psicológico/psicologia
15.
Artigo em Alemão | MEDLINE | ID: mdl-21246330

RESUMO

The aim of this article is to provide an overview on depression as a risk factor for the onset and follow-up of cardiovascular disease (CVD). In brief, the current state of psychobiological mechanisms bridging the gap between affective states and somatic consequences are presented. Four meta-analyses dealing with depression as a CVD risk factor in apparently healthy populations with >100,000 participants included, extracted an adjusted effect estimator of 1.60-1.90. Depressed subjects present with an unhealthier lifestyle (nutrition, smoking, physical activity). Three major psychobiological pathways directly acting on the circulatory system are under discussion: (1) hyperregulation of the autonomic nervous system (e.g., increased mean heart rate, increased heart rate responses, impaired heart rate variability), (2) overshooting stress responses of the endocrine system with impaired feedback mechanisms (e.g., for cortisol release), and (3) the immune system with dysregulated release of acute phase proteins and proinflammatory cytokines, all involved in a bidirectional crosstalk with the patient's affective state and leading to platelet activation and flow mediated endothelial (dys-)function. Nonadherence and adverse side effects of medications also contribute to the lethal properties of depression in CVD.


Assuntos
Doença das Coronárias/diagnóstico , Doença das Coronárias/mortalidade , Transtornos Mentais/diagnóstico , Transtornos Mentais/mortalidade , Psicoterapia/métodos , Psicoterapia/tendências , Doença Crônica , Alemanha/epidemiologia , Humanos , Incidência , Medição de Risco , Fatores de Risco , Análise de Sobrevida , Taxa de Sobrevida
16.
Int J Oral Maxillofac Surg ; 49(4): 522-528, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31570288

RESUMO

Infective endocarditis (IE) is a devastating disease with high mortality. Most guidelines recommend routine use of antibiotic prophylaxis during oral surgery to prevent IE in patients with specific predisposing cardiac conditions, but this is not the case in the UK. The conflicting opinions and guidance are confusing and may affect IE prophylaxis implementation. We investigated how IE prophylaxis standards are defined in hospitals and outpatient clinics of oral and maxillofacial surgery. A survey was sent to 80 surgeons heading departments of oral and maxillofacial surgery in Germany. We observed significant heterogeneity in IE prophylaxis implementation among the clinics. This diversity was in relation to the definition of predisposing cardiac conditions, the type of dental and surgical procedures performed that require IE prophylaxis, the spectrum of compounds used, and the timing of antibiotic prophylaxis. We observed under-prescription of IE prophylaxis in high-risk patients, the overuse of antibiotic prophylaxis in patients not at high risk of IE, and the use of inappropriate drugs. These findings suggest that educational strategies and guideline implementation advice are needed to improve standards of IE prophylaxis in oral and maxillofacial surgery clinics.


Assuntos
Endocardite Bacteriana , Endocardite , Cirurgia Bucal , Antibioticoprofilaxia , Alemanha , Humanos , Guias de Prática Clínica como Assunto
17.
Bioresour Technol ; 296: 122264, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31706135

RESUMO

A thermal balance modeling framework is developed, based on heat transfer-resistance networks. The heat transfer model accounts for effects of digester- design, location and operation, including effects of solar irradiance, external heating and ambient climate. We demonstrate extendibility of the framework by using the model in dynamic simulations of substrate temperature for digesters comprising two very different designs. Digester designs modeled include fixed-dome, buried, uninsulated and unheated household digesters in Hanoi, Vietnam, and an industrial-scale anaerobic digester located at a wastewater treatment plant in Esbjerg, Denmark. The modeled temperature profiles were evaluated against measured substrate temperatures over long periods, from 7 months and up. For the two Hanoi digesters, root-mean-square-error were 1.43 °C and 0.92 °C, with Nash-Sutcliffe model efficiency coefficients (NS-C) of 0.87 and 0.93 respectively. For the industrial digester in Esbjerg root-mean-square-error was 0.48 °C with an NS-C of 0.94. The model was not calibrated prior simulation, suggesting good predictive performance.


Assuntos
Biocombustíveis , Temperatura Alta , Anaerobiose , Reatores Biológicos , Dinamarca , Metano , Vietnã
18.
Science ; 165(3890): 285-7, 1969 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-17814829

RESUMO

Order-disorder transitions between ferrous iron and magnesium in orthopyroxenes [minerals close to the composition (Fe, Mg) SiO(3)] occur rapidly between approximately 480 degrees and 1000 degrees C. Disordering and ordering have been studied experimentally. The determination of the metastable ferrous iron site occupancy in orthopyroxenes from rapidly cooled volcanic rocks provides information on the cooling rates, especially from 600 degrees to 480 degrees C.

19.
Science ; 174(4009): 581-3, 1971 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-17831301

RESUMO

The distribution of magnesium and iron over the M1 and M2 positions in Bamle enstatite shocked at 1 megabar is highly disordered. It corresponds to an equilibrium distribution of at least 1000 degrees C. The distribution in samples shocked at 450 kilobars or less is undisturbed.

20.
Science ; 167(3918): 686-8, 1970 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-17781546

RESUMO

Site occupancy numbers for ferrous iron, magnesium, and calcium at the Ml and M2 sites in lunar clinopyroxenes are estimated from nuclear gamma-ray resonant absorption spectra of (57)Fe. The cation distribution is ordered; calcium and magnesium prefer M2 and Ml, respectively. The distribution corresponds to an equilibrium at a temperature lower than 680 degrees C. Crystals cleaved and sectioned by diamond-knife ultramicrotomy were examined by high-voltage (200 kv) electron microscopy and diffraction. Uniform 300-to 600-A-wide bands that correspond to single crystal domains were found. Correlation of the bands with magnetic ordering at low temperatures is considered.

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