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INTRODUCTION: This study investigates patients' experience of selected imaging examinations and how human experiences are transformed through technological mediation. METHOD: A qualitative study of patients' experiences during selected imaging examinations, centering on human-technology relations, was conducted. Data was gathered in two Danish hospitals, through semi-structured interviews and participant observations. The study included fifteen diagnostic imaging examination cases, distributed over three Computed Tomography (CT)-guided lung biopsy interventions, seven conventional CT examinations, and five Positron Emission Tomography CT examinations. The participating patients were undergoing investigation for cancer within Fast Track Cancer Referral Programs (FTCRP). The study has a philosophical approach to practice grounded in Postphenomenology and draws on anthropological studies of healthcare practice as its theoretical and analytical framework. RESULTS: Diagnostic imaging technologies were found to have existential implications creating hope and trust in patients. Patients demonstrated technological readiness, in their willingness to comply with examination criteria and the professional's instructions. The patient's primary concern was achieving a good examination result, for which they were prepared to push themselves beyond their usual limits. Participating in diagnostic imaging examinations may be viewed as a life crisis ritual, wherein patients are constituted as liminal beings, existing between healthy and sick. CONCLUSIONS: The existential implications of an imaging examination were clear in terms of hope and trust. Hope is related to life and death in two temporal perspectives: A future hope of surviving cancer and a present hope of being cancer-free. Hope was linked to avoiding despair and rested on trusting oneself to technology, thus, forming a circle of interrelated concepts. IMPLICATIONS FOR PRACTICE: Professionals need to recognize the patients' liminal passings yet, unnoticed transformative and existential implications, to perform better patient-centered care.
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Esperança , Pesquisa Qualitativa , Confiança , Humanos , Feminino , Masculino , Dinamarca , Tomografia Computadorizada por Raios X , Pessoa de Meia-Idade , Idoso , Entrevistas como Assunto , AdultoRESUMO
INTRODUCTION: Social media (SoMe) is widely used as a communication platform in everyday life. Also, healthcare professionals have embraced SoMe as a communication tool for both peers and patients. It is becoming an interactive tool for discussing professionals' issues and a place where learning and education occur. This study explores the specific patterns of SoMe use for radiographers' in the Nordic countries. The aim of this survey was to investigate radiographers use of social platforms in a professional setting. METHODS: A 29-item survey was prepared, and pilot-tested. The survey was produced in Danish a language that all Nordic countries master. In general, most Nordic languages are very similar. The survey was distributed by online platforms such as Facebook, LinkedIn, Twitter/X, and also distributed by newsletters by the Norwegian and Danish national radiographers societies. All data was collected anonymously. An Ethical Research approval was obtained from the University of Southern Denmark. RESULTS: A total of 242 respondents completed the survey (Denmark n = 183, Norway n = 48, Sweden n = 8, and n = 3 from other Scandinavian countries). The respondents included 186 females, 52 males and four were undisclosed. On average, the respondents spent approximately 2 h and 23 min daily on SoMe, with 27 min specifically dedicated to content relevant to radiographers. Facebook was the preferred platform with 93 % (n = 226). A total of 5.4 % (n = 13) respondents had experienced contact from patients and/or next of kin, while 92 % (n = 222) reported no such interactions and 2.9 % (n = 7) were undisclosed. A total of 52.8 % (n = 128) used SoMe in relation to courses, conferences, or online meetings. This shows that time spent on content relevant to radiographers imply that SoMe can be a relevant tool for reaching radiographers. CONCLUSION: The survey demonstrates radiographers' use of SoMe for personal and professional interest, with Facebook as the preferred social media platform. SoMe were mostly used during courses, conferences, or online meetings with half of the respondent reported using SoMe platforms during working hours. These results underscore the untapped potential of SoMe in professional healthcare settings. Additionally, the study offers insight into current practices, facilitating comparisons to identify trends in SoMe usage within the radiographer community. IMPLICATIONS FOR PRACTICE: The findings advocate for the strategic use of SoMe by radiographers', emphasizing professional networking and knowledge sharing. However, clear guidelines are necessary to ensure patient confidentiality and data security in these digital interactions.
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Mídias Sociais , Masculino , Feminino , Humanos , Pessoal Técnico de Saúde , Pessoal de Saúde , Noruega , SuéciaRESUMO
INTRODUCTION: This study investigated how patients expected and experienced to be put first and cared for in diagnostic imaging settings and how putting the patient first was operationalized in practice. METHODS: A qualitative field study was conducted in two Danish hospitals to investigate patients' expectations and experiences of care and involvement during CT examinations. Data collection methods included semi-structured interviews and participant observations of five examination cases. Three Computed Tomography (CT) guided lung biopsy intervention studies and two conventional CT studies of the chest of patients being investigated for lung cancer in Fast Track Cancer Referral Programs (FTCRP) were included. RESULTS: Patients reported low expectations of receiving care and being involved during examinations. Perceptions of receiving care predominantly consisted of being received in a kind, personalized manner. Expectations of involvement in the procedure were reported in terms of readiness to do as they were told, complying with requests put to each patient. Concepts of care and involvement were challenged in their formal meanings and found to be entangled in complex interactions within sociotechnical boundaries. CONCLUSION: Patient's expectations of receiving care and being involved in the diagnostic imaging procedures, were expressed in noncommittal terms, and were overshadowed by patients' focus on getting through the examination, in order to get an answer to their tentative diagnose. The concepts of care and patient involvement were negotiated and reconceptualized within the sociotechnical framework of the diagnostic imaging situation of the individual patient. The concept of "tinkering" is suggested as a means of understanding how patientcare is performed during diagnostic imaging procedures. IMPLICATIONS FOR PRACTICE: Issues were identified that may help professionals to put "the patient first", thus, improving patient centered care.
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Motivação , Participação do Paciente , Humanos , Pacientes , Pesquisa Qualitativa , Tomografia Computadorizada por Raios XRESUMO
BACKGROUND: Lower socioeconomic status (SES) is associated with higher mortality rates and the likelihood of receiving less evidence-based treatment after stroke. In contrast, little is known about the impact of SES on recovery after discharge from inpatient rehabilitation. The aim of this study was to investigate the influence of SES on long-term recovery after stroke. PATIENTS AND METHODS: In a prospective, observational, multicentre study, inpatients were recruited towards the end of rehabilitation. The 12-month follow-up focussed on upper limb motor recovery, measured by the Fugl-Meyer score. A clinically relevant improvement of ≥5.25 points was considered recovery. Patient-centric measures such as the Patient-reported Outcomes Measurement Information System-Physical Health (PROMIS-10 PH) provided secondary outcomes. Information on schooling, vocational training, income and occupational status pre-stroke entered a multidimensional SES index. Multivariate logistic regression models calculating odds ratios (ORs) and corresponding confidence intervals (CIs) were applied. SES was added to an initial model including age, sex and baseline neurological deficit. Additional exploratory analyses examined the association between SES and outpatient treatment. RESULTS: One hundred and seventy-six patients were enrolled of whom 98 had SES and long-term recovery data. Model comparisons showed the SES-model superior to the initial model (Akaike information criterion (AIC): 123 vs. 120, Pseudo R2: 0.09 vs. 0.13). The likelihood of motor recovery (OR = 17.12, 95%CI = 1.31; 224.18) and PROMIS-10 PH improvement (OR = 20.76, 95%CI = 1.28; 337.11) were significantly increased with higher SES, along with more frequent use of outpatient therapy (p = .02). CONCLUSIONS: Higher pre-stroke SES is associated with better long-term recovery after discharge from rehabilitation. Understanding these factors can improve outpatient long-term stroke care and lead to better recovery.KEY MESSAGEHigher pre-stroke socioeconomic status (SES) is associated with better long-term recovery after discharge from rehabilitation both in terms of motor function and self-reported health status.Higher SES is associated with significantly higher utilization of outpatient therapies.Discharge management of rehabilitation clinics should identify and address socioeconomic factors in order to detect individual needs and to improve outpatient recovery. Article registration: clinicaltrials.gov NCT04119479.
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Reabilitação Neurológica , Reabilitação do Acidente Vascular Cerebral , Acidente Vascular Cerebral , Humanos , Pacientes Internados , Estudos Prospectivos , Recuperação de Função Fisiológica , Classe Social , Reabilitação do Acidente Vascular Cerebral/métodos , Resultado do Tratamento , Extremidade SuperiorRESUMO
INTRODUCTION: The prevalence of acetabular retroversion is sparsely investigated. It may be associated with increased anterior pelvic tilt. The purpose of this study was to investigate whether patients with symptomatic and radiographically verified acetabular retroversion demonstrated increased anterior pelvic tilt compared to a control group, and furthermore to evaluate the prevalence of acetabular retroversion in the general population. METHODS: Anteroposterior pelvic radiographs in standing position of 111 patients with acetabular retroversion prior to anteverting periacetabular osteotomy (PAO) and 132 matched controls from the general Danish population were assessed. Pelvic tilt was assessed by the sacrococcygeal joint-symphysis distance and pelvic-tilt-ratio. Acetabular retroversion was defined as positive cross-over sign and posterior wall sign. Prior to assessments, interrater reliability analysis was performed. Measurements were agreed by two independent assessors. A nonparametric regression model was used to test between-group differences in median pelvic tilt. The prevalence was calculated as the ratio of subjects and hips with acetabular retroversion, respectively. RESULTS: The patient group had significantly larger median anterior pelvic tilt of 14.3 mm in sacrococcygeal joint-symphysis distance and -0.08 in pelvic-tilt-ratio, compared to controls. The prevalence of subjects in the general population with either unilateral or bilateral acetabular retroversion was 24% and 18% for all hips. CONCLUSION: Our data demonstrated that patients with symptomatic acetabular retroversion have increased anterior pelvic tilt compared to the general population. Radiographic sign of acetabular retroversion was highly prevalent in the general population. IMPLICATION FOR PRACTICE: Increased anterior pelvic tilt should be considered when diagnosing and treating patients with hip pain, as symptoms may be related to the functional position of the pelvis and not necessarily solely come from the radiographic verified acetabular retroversion.
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Acetábulo , Osteotomia , Acetábulo/diagnóstico por imagem , Estudos Transversais , Humanos , Reprodutibilidade dos Testes , Estudos RetrospectivosRESUMO
A rising wave of technologies and instruments are enabling more labs and clinics to make a variety of measurements related to tissue viscoelastic properties. These instruments include elastography imaging scanners, rheological shear viscometers, and a variety of calibrated stress-strain analyzers. From these many sources of disparate data, a common step in analyzing results is to fit the measurements of tissue response to some viscoelastic model. In the best scenario, this places the measurements within a theoretical framework and enables meaningful comparisons of the parameters against other types of tissues. However, there is a large set of established rheological models, even within the class of linear, causal, viscoelastic solid models, so which of these should be chosen? Is it simply a matter of best fit to a minimum mean squared error of the model to several data points? We argue that the long history of biomechanics, including the concept of the extended relaxation spectrum, along with data collected from viscoelastic soft tissues over an extended range of times and frequencies, and the theoretical framework of multiple relaxation models which model the multi-scale nature of physical tissues, all lead to the conclusion that fractional derivative models represent the most succinct and meaningful models of soft tissue viscoelastic behavior. These arguments are presented with the goal of clarifying some distinctions between, and consequences of, some of the most commonly used models, and with the longer term goal of reaching a consensus among different sub-fields in acoustics, biomechanics, and elastography that have common interests in comparing tissue measurements.
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Técnicas de Imagem por Elasticidade/métodos , Fígado/diagnóstico por imagem , Modelos Teóricos , Imagens de Fantasmas , Reologia , Animais , Bovinos , Consenso , Humanos , Interpretação de Imagem Assistida por Computador , ViscosidadeRESUMO
The Neutron Camera Upgrade (NCU) is a neutron flux monitor consisting of six lines of sight (LoSs) under installation on Mega Ampere Spherical Tokamak (MAST) Upgrade. The NCU is expected to contribute to the study of the confinement of fast ions and on the efficiency of non-inductive current drive in the presence of on-axis and off-axis neutral beam injection by measuring the neutron emissivity profile along the equatorial plane. This paper discusses the NCU main design criteria, the engineering and interfacing issues, and the solutions adopted. In addition, the results from the characterization and performance studies of the neutron detectors using standard γ-rays sources and a 252Cf source are discussed. The proposed design has a time resolution of 1 ms with a statistical uncertainty of less than 10% for all MAST Upgrade scenarios with a spatial resolution of 10 cm: higher spatial resolution is possible by moving the LoSs in-between plasma discharges. The energy resolution of the neutron detector is better than 10% for a light output of 0.8 MeVee, and the measured pulse shape discrimination is satisfactory.
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In this Letter, we report a resonant x-ray scattering measurement of stripelike charge order in the 1/8th doped component of electronically phase-separated, orthorhombic La_{2}CuO_{4+y}. This observation is coupled to the absence of any resonant (001) peak, which at different resonant energies has been identified with the presence of low-temperature-tetragonal-like structural tilt patterns or nematicity in the CuO planes. Thus, we provide evidence that structural pinning is not necessary for the formation of static charge stripes and that the relationship between charge nematicity and stripes may not be simple.
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We present detailed neutron scattering studies of the static and dynamic stripes in an optimally doped high-temperature superconductor, La_{2}CuO_{4+y}. We observe that the dynamic stripes do not disperse towards the static stripes in the limit of vanishing energy transfer. Therefore, the dynamic stripes observed in neutron scattering experiments are not the Goldstone modes associated with the broken symmetry of the simultaneously observed static stripes, and the signals originate from different domains in the sample. These observations support real-space electronic phase separation in the crystal, where the static stripes in one phase are pinned versions of the dynamic stripes in the other, having slightly different periods. Our results explain earlier observations of unusual dispersions in underdoped La_{2-x}Sr_{x}CuO_{4} (x=0.07) and La_{2-x}Ba_{x}CuO_{4} (x=0.095).
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Both physiologically and ecologically based explanations have been proposed to account for among-species differences in lifespan, but they remain poorly tested. Phylogenetically explicit comparative analyses are still scarce and those that exist are biased towards homoeothermic vertebrates. Insect studies can significantly contribute as lifespan can feasibly be measured in a high number of species, and the selective forces that have shaped it may differ largely between species and from those acting on larger animals. We recorded adult lifespan in 98 species of geometrid moths. Phylogenetic comparative analyses were applied to study variation in species-specific values of lifespan and to reveal its ecological and life-history correlates. Among-species and between-gender differences in lifespan were found to be notably limited; there was also no evidence of phylogenetic signal in this trait. Larger moth species were found to live longer, with this result supporting a physiological rather than ecological explanation of this relationship. Species-specific lifespan values could not be explained by traits such as reproductive season and larval diet breadth, strengthening the evidence for the dominance of physiological determinants of longevity over ecological ones.
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Tamanho Corporal , Longevidade , Mariposas , Animais , Ecologia , Larva , FilogeniaRESUMO
Development of safe and efficient radiotherapy routines requires quantification of the delivered absorbed dose to the cancer tissue in individual patients. In vivo dosimetry can provide accurate information about the absorbed dose delivered during treatment. In the current study, a novel silver-nanosensor formulation based on poly(vinylpyrrolidinone)-coated silver nanoparticles formulated in a gelation matrix composed of sucrose acetate isobutyrate has been developed for use as an in vivo dosimeter for external beam radiotherapy. In situ photonuclear reactions trigger the formation of radioactive (106)Ag, which enables post treatment verification of the delivered dose using positron emission tomography imaging. The silver-nanosensor was investigated in a tissue equivalent thorax phantom using clinical settings and workflow for both standard fractionated radiotherapy (2 Gy) and stereotactic radiotherapy (10- and 22 Gy) in a high-energy beam setting (18 MV). The developed silver-nanosensor provided high radiopacity on the planning CT-scans sufficient for patient positioning in image-guided radiotherapy and provided dosimetric information about the absorbed dose with a 10% and 8% standard deviation for the stereotactic regimens, 10 and 22 Gy, respectively.
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Dosimetria in Vivo , Nanopartículas Metálicas , Tomografia por Emissão de Pósitrons , Radioterapia , Prata , Humanos , Posicionamento do Paciente , Imagens de FantasmasRESUMO
OBJECTIVES: To study the efficacy of tailored behavioural medicine treatment within a physical therapy framework. METHODS: The study was a randomized controlled study (RCT): tailored behavioural medicine treatment (EXT) delivered by physical therapists (PTs) was compared with exercise-based treatment (CT). Thirty-two adolescents (mean age 14.3 years) with persistent pain participated. Data on pain-related disability and school attendance (primary outcomes), pain intensity, catastrophizing, fear of movement and self-efficacy were collected. RESULTS: The pain-related disability measured by the Functional Disability Inventory (FDI) resulted in mean score change of EXT = -18 and CT = -11, respectively. A significant change within both groups was found (EXT p = 0.003, CT p = 0.001), and a large effect size for FDI between the conditions was demonstrated (AUC of 0.77). For school attendance post-treatment, no difference was found between conditions. For secondary outcomes, a significant improvement in pain intensity and pain catastrophizing was found for the EXT and self-efficacy for the CT groups but no statistically significant difference between the two conditions was detected. Caution should be given to the small sample size, as it may affect the interpretation and generalizability of the results. CONCLUSION: In this study, differences between tailored behavioural medicine treatment delivered by PTs and exercise-based treatment could not be demonstrated, although the effect size was large. Patients who received either treatment demonstrated significant changes over time in pain-related disability. The low number of participants and suboptimal tailoring of the psychological components may partly explain the failure to demonstrate differences between groups, and future studies are warranted.
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Medicina do Comportamento , Exercício Físico , Manejo da Dor/métodos , Dor/psicologia , Modalidades de Fisioterapia , Atenção Primária à Saúde , Adolescente , Fatores Etários , Medo/psicologia , Feminino , Humanos , Masculino , Movimento , AutoeficáciaRESUMO
INTRODUCTION: Intra-articular knee fractures in children are rare. The Patient Compensation Association (PCA) receives claims for financial compensation from patients who believe they have sustained damage from their treatment in the health care system. We used relevant cases of closed claims to identify causality and co-factors contributing to these apparent malpractices. MATERIALS AND METHODS: A partial root core analysis was performed on closed claims from the PCA database concerning proximal tibial fractures in children aged ≤15 years. RESULTS: We identified 13 cases. The main complaint was missed diagnosis (6 cases)-fractures of the tibial eminence were the main culprit, with damage to the popliteal artery caused by a medial condyle fracture being the most serious. All cases were missed by junior doctors. Secondary complaints were problems with casting, dissatisfaction with correct treatment, and insufficient surgery or complications relating to surgery. Eight of the complaints were acknowledged, with six receiving financial compensation ranging from EUR 9,600 to EUR 70,000. Five out of the six cases of missed diagnosis were acknowledged. CONCLUSIONS: This study indicates that recognizing the degree of injury to the knee in children, which should include an X-ray examination, is key to preventing missed diagnosis and delayed and potentially more difficult surgery with long-lasting sequelae for the child. The PCA database seems to be a useful way to highlight systematic problems in the Danish health care system and could potentially be an important means to improving patient safety and preventing treatment-related injuries.
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Physical exercise increases peripheral insulin sensitivity, but regional differences are poorly elucidated in humans. We investigated the effect of aerobic exercise training on insulin-stimulated glucose uptake in five individual femoral muscle groups and four different adipose tissue regions, using dynamic (femoral region) and static (abdominal region) 2-deoxy-2-[¹8F]fluoro-d-glucose (FDG) PET/CT methodology during steady-state insulin infusion (40 mU·m⻲·min⻹). Body composition was measured by dual X-ray absorptiometry and MRI. Sixty-one healthy, sedentary [V(O2max) 36(5) ml·kg⻹·min⻹; mean(SD)], moderately overweight [BMI 28.1(1.8) kg/m²], young [age: 30(6) yr] men were randomized to sedentary living (CON; n = 17 completers) or moderate (MOD; 300 kcal/day, n = 18) or high (HIGH; 600 kcal/day, n = 18) dose physical exercise for 11 wk. At baseline, insulin-stimulated glucose uptake was highest in femoral skeletal muscle followed by intraperitoneal visceral adipose tissue (VAT), retroperitoneal VAT, abdominal (anterior + posterior) subcutaneous adipose tissue (SAT), and femoral SAT (P < 0.0001 between tissues). Metabolic rate of glucose increased similarly (~30%) in the two exercise groups in femoral skeletal muscle (MOD 24[9, 39] µmol·kg⻹·min⻹, P = 0.004; HIGH 22[9, 35] µmol·kg⻹·min⻹, P = 0.003) (mean[95% CI]) and in five individual femoral muscle groups but not in femoral SAT. Standardized uptake value of FDG decreased ~24% in anterior abdominal SAT and ~20% in posterior abdominal SAT compared with CON but not in either intra- or retroperitoneal VAT. Total adipose tissue mass decreased in both exercise groups, and the decrease was distributed equally among subcutaneous and intra-abdominal depots. In conclusion, aerobic exercise training increases insulin-stimulated glucose uptake in skeletal muscle but not in adipose tissue, which demonstrates some interregional differences.
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Tecido Adiposo Branco/metabolismo , Exercício Físico , Transportador de Glucose Tipo 4/metabolismo , Glucose/metabolismo , Resistência à Insulina , Músculo Esquelético/metabolismo , Sobrepeso/terapia , Tecido Adiposo Branco/diagnóstico por imagem , Tecido Adiposo Branco/efeitos dos fármacos , Adiposidade , Adulto , Transporte Biológico/efeitos dos fármacos , Índice de Massa Corporal , Meios de Contraste/metabolismo , Fluordesoxiglucose F18/metabolismo , Técnica Clamp de Glucose , Transportador de Glucose Tipo 4/biossíntese , Humanos , Hipoglicemiantes/metabolismo , Hipoglicemiantes/farmacologia , Insulina/metabolismo , Insulina/farmacologia , Estudos Longitudinais , Masculino , Imagem Multimodal , Músculo Esquelético/diagnóstico por imagem , Músculo Esquelético/efeitos dos fármacos , Sobrepeso/metabolismo , Tomografia por Emissão de Pósitrons , Tomografia Computadorizada por Raios X , Regulação para Cima , Adulto JovemRESUMO
The potential for fiber exposure during historical use of chrysotile-containing joint compounds (JCC) has been documented, but the published data are of limited use for reconstructing exposures and assessing worker risk. Consequently, fiber concentration distributions for workers sanding JCC were independently derived by applying a recently developed model based on published dust measurements from sanding modern-day (asbestos-free) joint compound and compared to fiber concentration distributions based on limited historical measurements. This new procedure relies on factors that account for (i) differences in emission rates between modern-day and JCC and (ii) the number of fibers (quantified by phase contrast microscopy [PCM]) per mass of dust generated by sanding JCC, as determined in a bench-scale chamber study using a recreated JCC, that convert respirable dust concentrations to fiber concentrations. Airborne respirable PCM-fiber concentration medians (and 95% confidence intervals) derived for output variables using the new procedure were 0.26 (0.039, 1.7) f/cm(3) and 0.078 (0.013, 0.47) f/cm(3) , and corresponding total fiber concentrations were 1.2 (0.17, 9.2) f/cm(3) and 0.37 (0.056, 2.5) f/cm(3) , in enclosed and nonenclosed environments, respectively. Corresponding estimates of respirable and total PCM fiber concentrations measured historically during sanding of asbestos-containing joint compound-adjusted for differences between peak and time-weighted average (TWA) concentrations and documented analytical preparation and sampling artifacts-were 0.15 (0.019, 0.95) f/cm(3) and 0.86 (0.11, 5.4) f/cm(3) , respectively. The PCM-fiber concentration distributions estimated using the new procedure bound the distribution estimated from adjusted TWA historical fiber measurements, suggesting reasonable consistency of these estimates taking into account uncertainties addressed in this study.
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Asbestos Serpentinas/intoxicação , Fibras Minerais/intoxicação , Modelos Estatísticos , Doenças Profissionais/etiologia , Exposição Ocupacional/efeitos adversos , Medição de Risco/métodos , Poeira , Humanos , Microscopia de Contraste de Fase , Tamanho da PartículaRESUMO
Simulation studies for a full-scale anaerobic unit of a wastewater treatment plant (WWTP) were performed using the anaerobic digestion model no. 1 (ADM1). The anaerobic full-scale plant consists of one mesophilic and one thermophilic digester, operated in an anaerobic sequential batch reactor (ASBR) mode, and sludge enrichment reactors (SER) for each digester. The digesters are fed with a mixture of vegetable waste and process wastewater from the food factory. Characteristics such as COD(total), N(total) and NH(4)-N concentrations in the influent and effluent of the digester and SERs were measured and used for input fractionation. Parameters such as level, pH, biogas amount and composition in the digester were measured online and used for calibration. For simulation studies, different temperatures and operation modes with varying chemical oxygen demand (COD) input loads corresponding to feedstocks such as fruits, vegetables and grain were analysed and compared. Higher gas production and digestion efficiency in the thermophilic reactor and in shorter cycles were found and confirmed at full scale. Serial operation mode increased the gas production, but pH inhibition occurred earlier. Feeding only biosolids into digester I and the effluent of digester I together with process water into digester II further improved gas production in serial operation mode.
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Reatores Biológicos , Simulação por Computador , Eliminação de Resíduos Líquidos/métodos , Água/química , Anaerobiose , Arquitetura de Instituições de Saúde , Esgotos , TemperaturaRESUMO
Models for engineering design of nitrifying systems use one ammonia oxidizer biomass (AOB) state variable. A simple extension using two AOB populations allows a more accurate prediction of nitrification systems at switching process environments. These two AOB subpopulations are characterized by two different sets of kinetic parameters. Selection pressure and competition between the two functional AOB populations are determined by process conditions as demonstrated by three case studies: Case study I describes dynamics of two AOB populations showing different temperature sensitivities (modified Arrhenius term on growth and decay) when bioaugmented from the warm sidestream treatment environment to the cold mainstream and vice-versa. Case study II investigates competition between fast growing micro-strategists and k-strategists adjusted to low ammonia levels depending on the internal mixed liquor recycle rate (IMLR). Case study III shows that AOB transferred from the waste activated sludge of an SBR to the parallel continuous flow system with different decay kinetics can overgrow or coexist with the original population.