Vaihejakomallista iteratiiviseen kehittämiseen: Prosessimallin muutosten vaikutukset järjestelmäkehityksen laatuun

Siirretty Doriast

Assessment of decarbonization potential for circular economy value chains using simplified lifecycle assessment approach : Methodological development and case studies in the Turku region

The study aimed to develop and test a simplified life cycle assessment (SLCA) based tool for evaluating decarbonization potential in circular economy value chains. Climate change mitigation is one of the sustainable development goals. Creating carbon sinks, where the once-emitted CO2 can be stored or absorbed, is one way to slow down the accumulation of CO2 in the atmosphere. Being able to quantify a company’s potential to create carbon sinks is crucial to meeting the EU and regional emission goals. There was no suitable tool available for the presented issue. The study was executed in two parts: first, the SLCA-based tool was developed and then the tool was tested with three circular economy value chains and their improvement scenarios in the Turku region. The development of the calculator started with a literature review of the value chain in question, then the most impactful flows were determined and after that, the data collection was done. Finally, the method was applied to a spreadsheet calculator, and the global warming potential and decarbonization potential results were analyzed and interpreted. The assessment system boundary was set to gate-to-gate and only the parts of the process that would be changing were assessed in the comparison study. Three case studies were assessed: municipal solid waste incineration (MSWI) with a monoethanolamine (MEA) carbon capture unit, a biogas plant with carbon capture from membrane separation, and a comparison of natural and recycled aggregate production. The recycled aggregate raw material was demolished concrete. For the MSWI and biogas case, the decarbonization potential scenarios were identified in collaboration with industry experts and for the aggregate case, both scenarios were already in use. The annual decarbonization potentials of the MSWI, biogas, and aggregate cases were 19.6 kt CO2-eq/a, 5.7 kt CO2-eq/a, and 9.97 kt CO2-eq/a respectively. When compared to Turku’s annual emissions the studied value chains would decrease the emissions by 3%, 0.8%, and 1.5% respectively. The analysis showed that the MSWI case had the greatest decarbonization potential, but the operational emission from the MEA unit was 171 kg CO2-eq/t CO2 captured. The biogas case resulted in less decarbonization potential but the operational emissions of only compressing the already very concentrated CO2 stream were only 8.4 kg CO2-eq/t CO2 captured. The aggregate case was more affected by the choice of renewable fuel than the replacing natural aggregate with recycled aggregate. The SLCA approach could be used in a circular economy context and the performance of different improvement scenarios could be compared. The method was sensitive to assumptions due to its simple functionality. For future studies, the simplified method should be compared to full LCA, and the captured CO2 management should be investigated in environmental assessment. The presented method was intended to be used in case-by-case comparison studies for a simple first calculation step to quantify the decarbonization potential. Applying the method requires still expertise to avoid misleading assumptions, but the method can present valuable knowledge when comparing different improvement scenarios. The decarbonization potential assessment showed, that the CE improvement scenarios can create a 5% decrease in the area’s emissions.Tutkimuksen tavoitteena oli kehittää ja testata yksinkertaistettuun elinkaariarviointiin (SLCA) perustuva työkalu, jolla voidaan tutkia potentiaalisia hiilinieluja kiertotalouden arvoketjuissa. Ilmastonmuutoksen hillitseminen on yksi kestävän kehityksen tavoitteista ja hiilinielujen lisääminen on yksi tapa hidastaa hiilidioksidin kerääntymistä ilmakehään. Hiilinielu adsorboi tai pidättää hiilidioksidia, joka muuten päätyisi ilmakehään. Jotta yritykset voivat saavuttaa alueelliset ja EU:n hiilineutraaliustavoitteet, pitää potentiaalisten hiilinielujen laajuus määrittää. Määritykseen sopivaa työkalua ei ollut käytettävissä. Työ suoritettiin kahdessa vaiheessa: ensin kehitettiin SLCA metodiin perustuva työkalu ja toisessa vaiheessa työkalua pilotoitiin määrittämällä kolmen kiertotalouden arvoketjun hiilinielupotentiaali Turun alueella. Työkalun kehitys aloitettiin kirjallisuuskatsauksella tutkittavista arvoketjuista, seuraavaksi tunnistettiin vaikuttavimmat materiaalivirrat ja suoritettiin tutkimusaineiston kokoaminen. Aineiston avulla muodostettiin Excel-laskuri. Viimeiseksi ilmastovaiku-tus (GWP) ja hiilinielupotentiaali analysoitiin ja tulkittiin. Ilmastovaikutuksen arviointi rajattiin koskemaan vain tuotantoprosessia ja laskentaan otettiin mukaan vain yksikköprosessit, jotka muuttuivat kehitysskenaarion lisäämisen myötä. Työssä tutkittiin kolme arvoketjua: hiilidioksidin talteenotto hyötyvoimalaitoksen savukaa-suista monoetanoliamiinilla (MEA), hiilidioksidin talteenotto biokaasun membraaniprosessista kompressoimalla ja luonnonkivimurskeen sekä betonimurskeen tuotantoprosessien vertailu. Arvoketjujen mahdollisia parannuskohteita kehitettiin yhteistyössä alan ammattilaisten kanssa. Hyötyvoimalaitoksen tapauksessa vuotuinen hiilinielupotentiaali oli 19,6 kt CO2-ekv/a. Biokaasulaitoksen tapauksessa vuotuinen hiilinielupotentiaali oli 5,7 kt CO2-ekv/a. Murskeiden tapauksessa varsinaista hiilinielua ei syntynyt, mutta vuotuinen päästövähennys oli 9,97 kt CO2-ekv/a. Tutkimuksesta kävi ilmi, että hyötyvoimalaitos voisi tuottaa suurimman nielun, mutta MEA prosessin operoinnin päästöt olivat suuret, 171 kg CO2-ekv/t CO2 talteenotettu. Biokaasulaitoksen tapauksessa hiilidioksidi saatiin helpommin talteen pelkästään kompressoimalla membraaniprosessin CO2-rikas poistokaasu ja talteenoton päästöt olivat vain 8,4 kg CO2-ekv/t CO2. Murskeiden tapauksessa huomattiin, että käyttämällä uusiutuvaa polttoainetta, saataisiin suurempi päästövähennys aikaan kuin vaihtamalla luonnonkivimurske betonimurskeeseen. Yksinkertaistettua elinkaariarviointia voitiin hyödyntää kiertotalouden prosessien arvioimisessa ja kehitysskenaarioiden tehokkuutta voitiin vertailla keskenään. Koska metodi oli hyvin yksinkertainen, tehdyt oletukset vaikuttivat helposti tuloksiin. Tulevissa tutkimuksissa yksinkertaistettua metodia tulisi verrata perusteelliseen elinkaariarviointiin ja talteen otetun hiilidioksidin vaatimien prosessien ympäristövaikutus tulisi ottaa mukaan tutkimukseen. Työssä esitetty metodi oli tarkoitettu käytettäväksi tapauskohtaisesti yksinkertaiseksi ensimmäiseksi askeleeksi hiilinielupotentiaalin määritykseen. Metodin käyttäminen vaatii silti ammattitaitoa, jotta harhaanjohtavilta oletuksilta vältytään. Kaiken kaikkiaan metodi tarjoaa arvokasta tietoa vaihtoehtoisista kehitysskenaarioista ja tutkituilla kiertotalouden prosessien kehittämisellä saataisiin 5 % vähennys Turun päästöihin

Measurement of splanchnic photoplethysmographic signals using a new reflectance fiber optic sensor

Splanchnic organs are particularly vulnerable to hypoperfusion. Currently, there is no technique that allows for the continuous estimation of splanchnic blood oxygen saturation (SpO(2)). As a preliminary to developing a suitable splanchnic SpO(2) sensor, a new reflectance fiber optic photoplethysmographic (PPG) sensor and processing system are developed. An experimental procedure to examine the effect of fiber source detector separation distance on acquired PPG signals is carried out before finalizing the sensor design. PPG signals are acquired from four volunteers for separation distances of 1 to 8 mm. The separation range of 3 to 6 mm provides the best quality PPG signals with large amplitudes and the highest signal-to-noise ratios (SNRs). Preliminary calculation of SpO(2) shows that distances of 3 and 4 mm provide the most realistic values. Therefore, it is suggested that the separation distance in the design of a fiber optic reflectance pulse oximeter be in the range of 3 to 4 mm. Preliminary PPG signals from various splanchnic organs and the periphery are obtained from six anaesthetized patients. The normalized amplitudes of the splanchnic PPGs are, on average, approximately the same as those obtained simultaneously from the periphery. These observations suggest that fiber optic pulse oximetry may be a valid monitoring technique for splanchnic organs

Cerebral glucose metabolism on positron emission tomography of children

Establishing the normative range of age-dependent fluorodeoxyglucose (FDG) uptake in the developing brain is necessary for understanding regional quantitative analysis of positron emission tomography (PET) brain images in children and also to provide functional information on brain development. We analyzed head sections of FDG PET/computed tomography (CT) images for 115 patients (5 months to 23 years) without central nervous system disease before treatment, as PET studies are not performed on healthy children owing to ethical considerations and the risk of radiation exposure. We investigated the changes in FDG uptake and established age-associated normative ranges of cerebral FDG. Head sections of FDG PET/CT images were registered to a population-based probabilistic atlas of human cortical structures. Gray matter of 56 brain structures was defined on normalized PET images according to the atlas. To avoid individual and experimental confounding factors, the relative standardized uptake value (SUV) over the cerebellum of each structure was calculated. Relative SUVs were analyzed by ANOVA and modeled using generalized estimating equalization analysis with false discovery rate control. Age and structure were significant factors affecting SUVs. Anatomic proximity had little effect on FDG uptake. Linear and quadratic developmental trajectories were observed on absolute and relative SUVs, respectively. An increase from posterior-to-anterior and superior-to-inferior pattern was observed in both absolute SUV increase rate and relative SUV peak age. The SUV of each structure was modeled with respect to age, and these models can serve as baselines for the quantitative analysis of cerebral FDG-PET images of children

Investigation of photoplethysmographic signals and blood oxygen saturation values obtained from human splanchnic organs using a fiber optic sensor

Objective A reliable, continuous method of monitoring splanchnic organ oxygen saturation could allow for the early detection of malperfusion, and may prevent the onset of multiple organ failure. Current monitoring techniques have not been widely accepted in critical care monitoring. As a preliminary to developing a continuous indwelling device, this study evaluates a new handheld fiber optic photoplethysmographic (PPG) sensor for estimating the blood oxygen saturation (SpO2) of splanchnic organs during surgery. Methods A fiber optic splanchnic PPG sensor, instrumentation system and virtual instrument were developed to facilitate PPG and SpO2 measurement from splanchnic organs. Following Local Research Ethics Committee approval, the sensor was evaluated on seventeen ASA 1 and 2 patients undergoing open laparotomy. PPG signals were obtained from the large bowel, small bowel, liver and stomach. Simultaneous PPG signals from the finger were also obtained using an identical fiber optic sensor. Results Good quality PPG signals with high signal-to-noise (SNR) ratios were obtained from all splanchnic sites under investigation. Analysis of the ac and dc amplitudes of the red and infrared PPG signals showed there to be a statistically significant difference between PPG signals obtained from splanchnic organs with those obtained from the finger (using fiber optic sensors). Estimated SpO2 values from the splanchnic organs show good agreement with those obtained from the finger using both a fiber optic sensor and a commercial device. Furthermore, the results of a Bland and Altman analysis indicate that fiber optic splanchnic pulse oximetry, particularly of the bowel, may provide a suitable method for monitoring splanchnic organ perfusion. Conclusion The evaluation of a new fiber optic sensor on anaesthetized patients undergoing laparotomy demonstrated that good quality PPG signals and SpO2 estimates can be obtained from splanchnic organs. Such a sensor may provide a useful tool for the intraoperative assessment of splanchnic perfusion

Age-dependent electroencephalogram (EEG) patterns during sevoflurane general anesthesia in infants

Electroencephalogram (EEG) approaches may provide important information about developmental changes in brain-state dynamics during general anesthesia. We used multi-electrode EEG, analyzed with multitaper spectral methods and video recording of body movement to characterize the spatio-temporal dynamics of brain activity in 36 infants 0–6 months old when awake, and during maintenance of and emergence from sevoflurane general anesthesia. During maintenance: (1) slow-delta oscillations were present in all ages; (2) theta and alpha oscillations emerged around 4 months; (3) unlike adults, all infants lacked frontal alpha predominance and coherence. Alpha power was greatest during maintenance, compared to awake and emergence in infants at 4–6 months. During emergence, theta and alpha power decreased with decreasing sevoflurane concentration in infants at 4–6 months. These EEG dynamic differences are likely due to developmental factors including regional differences in synaptogenesis, glucose metabolism, and myelination across the cortex. We demonstrate the need to apply age-adjusted analytic approaches to develop neurophysiologic-based strategies for pediatric anesthetic state monitoring.National Institutes of Health (U.S.) (R01-GM104948)National Institutes of Health (U.S.) (DP2-OD006454)Massachusetts General Hospita

Early blood glucose profile and neurodevelopmental outcome at two years in neonatal hypoxic-ischaemic encephalopathy

Background: To examine the blood glucose profile and the relationship between blood glucose levels and neurodevelopmental outcome in term infants with hypoxic-ischaemic encephalopathy. Methods: Blood glucose values within 72 hours of birth were collected from 52 term infants with hypoxic-ischaemic encephalopathy. Hypoglycaemia [ 150 mg/dL (8.3 mmol/L)] were correlated to neurodevelopmental outcome at 24 months of age. Results: Four fifths of the 468 blood samples were in the normoglycaemic range (392/468:83.8%). Of the remaining 76 samples, 51.3% were in the hypoglycaemic range and (48.7%) were hyperglycaemic. A quarter of the hypoglycaemic samples (28.2%:11/39) and a third of the hyperglycaemic samples (32.4%:12/37) were recorded within the first 30 minutes of life. Mean (SD) blood glucose values did not differ between infants with normal and abnormal outcomes [4.89(2.28) mmol/L and 5.02(2.35) mmol/L, p value = 0.15] respectively. In term infants with hypoxic-ischaemic encephalopathy, early hypoglycaemia (between 0-6 hours of life) was associated with adverse outcome at 24 months of age [OR = 5.8, CI = 1.04-32)]. On multivariate analysis to adjust for grade of HIE this association was not statistically significant. Late hypoglycaemia (6-72 hours of life) was not associated with abnormal outcome [OR = 0.22, CI (0.04-1.14)]. The occurrence of hyperglycaemia was not associated with adverse outcome. Conclusion: During the first 72 hours of life, blood glucose profile in infants with hypoxic-ischaemic encephalopathy varies widely despite a management protocol. Early hypoglycaemia (0-6 hours of life) was associated with severe HIE, and thereby; adverse outcome

Positron emission tomography methods with potential for increased understanding of mental retardation and developmental disabilities

Positron emission tomography (PET) is a technique that enables imaging of the distribution of radiolabeled tracers designed to track biochemical and molecular processes in the body after intravenous injection or inhalation. New strategies for the use of radiolabeled tracers hold potential for imaging gene expression in the brain during development and following interventions. In addition, PET may be key in identifying the physiological consequences of gene mutations associated with mental retardation. The development of high spatial resolution microPET scanners for imaging of rodents provides a means for longitudinal study of transgenic mouse models of genetic disorders associated with mental retardation. In this review, we describe PET methodology, illustrate how PET can be used to delineate biochemical changes during brain development, and provide examples of how PET has been applied to study brain glucose metabolism in Rett syndrome, serotonin synthesis in autism, and GABA A receptors in Angelman's syndrome and Prader–Willi syndrome. Future application of PET scanning in the study of mental retardation might include measurements of brain protein synthesis in fragile X syndrome and tuberous sclerosis complex, two common conditions associated with mental retardation in which cellular mechanisms involve dysregulation of protein synthesis. Mental retardation results in life-long disability, and application of new PET technologies holds promise for a better understanding of the biological underpinnings of mental retardation, with the potential to uncover new treatment options. © 2005 Wiley-Liss, Inc. MRDD Research Reviews 2005;11:325–330.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/48773/1/20086_ftp.pd