466 research outputs found
Instrument Development - Cloud Condensation Nuclei Counter
A cloud condensation nuclei counter (CCNC) is used to study the ability of aerosol particles to serve as cloud condensation nuclei (CCN) depending on their size, chemical composition and the ambient water super saturation. In this study, the new operation mode Scanning Flow CCN Analysis (SFCA) was evaluated for the Continuous-Flow Streamwise Thermal-Graident Cloud Condensation Nuclei Counter from Droplet Measurement Technologies (CCNC DMT-100). By continuously changing the flow rate through the instrument, while keeping the streamwise temperature gradient and pressure constant, the SFCA enables measurements of entire super saturation spectra with high temporal resolution. The SFCA was evaluated for three magnitudes of the streamwise thermal gradient (4, 10 and 18 K) using three types of calibration particles (sodium chloride, ammonium sulfate and sucrose). By examining the flow rates at which the particles activated into cloud droplets, the critical flow rates could be related to the critical super saturations found from Köhler theory. In this way, calibrations between the flow rates and super saturations of the CCNC were obtained. Nine calibration curves were obtained in total, one for each substance and streamwise temperature gradient. To verify the validity of the curves, 95% confidence intervals were calculated. The calibration curves were then compared with each other to evaluate the reability of the operation mode. The SFCA was found to be reliable for streamwise temperature gradients of 4 and 10 K, but somewhat less reliable for a temperature gradient of 18 K. The calibration curves were also found to be the least reliable at the ends
Accessible forest bathing : increased availability of nature
Med dagens teknikfokuserade och urbaniserade samhÀlle följer mycket stress och psykisk ohÀlsa. Personer med olika former av funktionsnedsÀttning mÄr dÄligt i högre grad Àn resterande befolkning. Dessutom ökar antalet personer med funktionsnedsÀttning bland annat pÄ grund av stigande Älder pÄ befolkningen.
Skogsbad Àr en lÀttillgÀnglig form av naturterapi som innebÀr en rekreativ vistelse i skog dÀr omgivningen uppmÀrksammas genom sinnena. HÀlsoeffekterna Àr mÄnga, bÄde psykiska och fysiska och handlar till stor del om stressreducering och ÄterhÀmtning. Sverige har stora arealer skog och allemansrÀtten ger mÄnga möjlighet att vistas i den. Naturen kan dock innehÄlla Ätskilliga hinder för personer med fysisk funktionsnedsÀttning som mÄnga gÄnger inte kan ta del av dess rekreerande effekter.
Syftet med detta arbete Àr att undersöka vilka platskvalitéer som Àr fördelaktiga vid utövande av skogsbad samt hur skogsbad kan tillgÀngliggöras för personer med fysisk funktionsnedsÀttning. För att undersöka platskvalitéer för skogsbad och hur skogsbad kan tillgÀngliggöras utfördes litteratur- och dokumentinsamling samt kvalitativa intervjuer med skogsbadsguider och tillgÀnglighetskonsulter.
I detta arbete behandlas aspekter gÀllande utformningen av tillgÀnglighetsanpassade anlÀggningar med syfte att underlÀtta skogsbad. Resultatet Àr indelat i Skogsbadsutövande, Upplevelse och estetik och TillgÀngligt skogsbad.
Under sjÀlva skogsbadsutövandet utforskas omgivningen intuitivt och uppmÀrksamt genom sinnena hörsel, syn, smak, doft och kÀnsel. Effekten av skogsbad skiljer sig inte markant mellan olika skogstyper, det finns dock vissa företeelser som mÄnga mÀnniskor uppskattar och som kan stÀrka upplevelsen, sÄsom ljudet av tystnad och vattenfunktioner.
Att utforma och anpassa en miljö för skogsbad innebÀr att ta hÀnsyn och hitta en balans mellan byggda element och bevarande av naturkÀnslan.
TillgÀnglighetsanpassning ökar möjligheten för fler mÀnniskor att ta del av naturen pÄ lika villkor utifrÄn deras olika förutsÀttningar. I skogsbadsmiljöer kan detta bland annat innebÀra att möjliggöra framkomlighet och ÄterhÀmtning för personer med nedsatt rörelse- eller orienteringsförmÄga samt att information, faciliteter och olika hjÀlpmedel utformas pÄ ett sÀtt som kan underlÀtta för personer med fysiska funktionsnedsÀttningar.
Att uppfylla alla personers individuella krav pÄ tillgÀnglighet kan vara mycket svÄrt, speciellt nÀr balansen mellan tillrÀttalagd och vild natur Àr hÄrfin. Vi menar dock att tillgÀnglighetsanpassning
kan öka tillgÄngen till naturen för mÄnga och om det görs pÄ ett eftertÀnksamt och omsorgsfullt vis finns stor potential för skogsbad för fler
Syrgasburars arbetsluckor
Patienter i behov av syrgas Àr frekvent förekommande pÄ intensivvÄrdsavdelningar pÄ svenska
djursjukhus. Det finns flera metoder för administrering av syrgas till djur, varav en Àr syrgasburar.
Metoderna för syrgasadministrering har olika för- och nackdelar. De kan bland annat medföra olika
grader av stress hos patienten samt variera i uppnÄdd syrgaskoncentration. Böcker inom
djursjukvÄrd och syrgasterapi anger att en nackdel hos syrgasburar Àr att syrgaskoncentrationen
sjunker avsevÀrt vid anvÀndandet av arbetsluckor, vilket försvÄrar vÄrd av patienten. Effektiv
syrgasadministrering beror till stor del pÄ personalens kunskap om utrustningen och dess funktioner.
Denna studie Àmnar dÀrför att i en praktisk studie undersöka pÄverkan pÄ syrgaskoncentration vid
anvÀndandet av arbetsluckor, samt genom en enkÀt undersöka personalens uppfattning kring
anvÀndandet av arbetsluckor. Syrgaskoncentrationen mÀttes i fyra burar av tvÄ olika mÀrken, dÀr de
tvÄ burarna av samma mÀrke var placerade ovanpÄ varandra. Syrgaskoncentrationen mÀttes efter 0s,
30s, 45s, 60s, 1:45 min, 3:30 min, 5 min och 10 min anvÀndning av arbetsluckor. Resultatet
jÀmfördes mellan höger och vÀnster burhalva, övre och nedre buren, och de tvÄ mÀrkena av
syrgasbur. Studien fann en statistisk signifikant skillnad mellan mÀrke och dÀrför utformning av de
fyra syrgasburarna, dÀr Syrgasbur 1 behöll minst 30% syrgas i strax under 10 min anvÀndning av
arbetsluckor och Syrgasbur 2 mellan 1:45 min och 3:30 min. I Syrgasbur 1 fanns en statistisk
signifikant skillnad mellan den övre och nedre buren vid alla tidpunkter. EnkÀtstudien tilldelades
personal pÄ den intensivvÄrdsavdelning dÀr den praktiska studien utfördes. Genom enkÀtens frÄgor
skattades anvÀndnadet av arbetsluckor utifrÄn pÄverkan pÄ tidsÄtgÄng, anvÀndarvÀnlighet, ergonomi
och hur ofta de anvÀndes. Dessa skattningar samt fritextsvar, angav att personalen generellt anser
att kliniska moment kompliceras vid utförande genom arbetsluckor pÄ syrgasburar. EnkÀten visade
att vissa kliniska moment utfördes i lÀgre grad genom arbetsluckor i jÀmförelse med att öppna dörr
till syrgasbur. Utformning och hur arbetsluckorna anvÀnds pÄverkar förlusten av syrgas i
syrgasburar.Patients in need of oxygen therapy are frequently seen in the intensive care unit at Swedish animal
hospitals. There are several methods for administrating oxygen to animals, including oxygen cages.
The methods of oxygen administration have different pros and cons, including variation in inducing
stress and achieved oxygen concentration. Books about animal health care and oxygen therapy
claims that a disadvantage of oxygen cages is the rapid loss of oxygen when using the portholes,
which complicates the care of the patient. Effective oxygen administration depends on the
knowledge of the personnel concerning the equipment and its functions. Therefore, this study aims
to examine the effects of the use of portholes on the oxygen concentration. Additionally, a survey
will examine the personnelâs view of the use of portholes. The oxygen concentration was measured
in four cages of two different brands, where the two cages of the same brand was placed on top of
each other. The oxygen concentration was measured after 0s, 30s, 45s, 60s, 1:45 min, 3:30 min, 5
min and 10 min usage of portholes. The result was compared between right and left cage half, upper
and lower cage, and between the two brands of cages. The study found a statistical significance
between brands and therefore cage design of the four oxygen cages, where Oxygen Cage 1 kept at
least 30% oxygen for just below 10 min usage of port holes and Oxygen Cage 2 between 1:45 min
and 3:30 min. In Oxygen Cage 1 there was a statistical significance between the upper and the lower
cage at every time period. The survey was distributed to personnel at the intensive care unit where
the practical study was performed. The portholes effect on time, user-friendliness, ergonomics, as
well as frequency of use, was rated through the questions in the survey. Through these ratings, as
well as open questions, the personnel answered that the portholes complicated performance of
certain tasks in care of the patient. According to the survey, the portholes were used at a lower
frequency compared to opening the door of the oxygen cage during these tasks. The design and how
the portholes are used affects the loss of oxygen in oxygen cages
BottomâUp Assessment Framework for Electrification Options in Energy-Intensive Process Industries
Electrification of industrial processes is one of the frequently discussed options to reduce greenhouse gas emissions from energy-intensive industries. This paper presents a bottomâup framework to assess process electrification options for energy-intensive industrial process plants in terms of greenhouse gas emissions and energy costs. The framework is based upon pinch analysis energy targetting methods, and accounts for site-specific conditions, including the effects on heat recovery potential and overall mass and energy balances. Furthermore, interactions between the process site and the background energy system are considered and scenarios are introduced in order to assess the impact of electrification options under different possible future energy market conditions. The framework is illustrated by a case study for an existing chemical plant for which there is a broad variety of electrification options that affect the process in different ways. The option of replacing the natural gas based syngas production unit with electrified syngas and steam production is analysed in detail. The results indicate natural gas savings of 173 MW whereas the electricity demand increases by 267 MW, leading to a strong increase in energy costs but also avoided greenhouse gas emissions of 333 kt/a. For two selected energy market scenarios for 2030 and 2040, the energy costs increase by 59 and 50 MâŹ/a, respectively. The framework can be used to compare electrification with other process greenhouse gas emission reduction measures and to support policy and industrial decision making
Characterization and visualization of industrial excess heat for different levels of on-site process heat recovery
Increased utilization of industrial excess heat (or waste heat) can reduce primary energy use and thereby contribute to reaching energy and climate targets. To estimate the potential availability of industrial excess heat, it is necessary to capture the significant heterogeneity of the industrial sector. This requires the development of methodologies based on case study assessments of individual plants, adopting a systematic approach and consistent assumptions. Since the recovery of excess heat for power generation or off-site delivery competes with internal recovery for on-site fuel savings, a well-founded approach should enable a comparison of the excess heat availability at different levels of internal process heat recovery. To determine the best solution for excess heat utilization for a given process, there is a need for easy screening of various options, while considering that some techniques require heat at a constant temperature while others can exploit a nonisothermal heat supply. This paper presents a new tool, the excess heat temperature (XHT) signature, for exploring the potential heat availability and trade-offs for excess heat utilization by weighting the heat according to predefined temperature levels and ranges. A set of reference conditions are defined, and an energy targeting approach is proposed that can be used for characterizing the Theoretical XHT signature, which represents the unavoidable excess heat that can be recovered after maximized internal process heat recovery and ideal integration of a power generation steam cycle. The Theoretical XHT signature is contrasted with the Process Cooling XHT signature, which represents the excess heat that can be recovered given the current design and operation of the process and its utility system. The XHT signature curves provide a consistent representation of the excess heat, enabling comparison between sites and aggregation of results from different case studies
Resolving issues of scaling for gramian-based inputâoutput pairing methods
A key problem in process control is to decide which inputs should control which outputs. There are multiple ways to solve this problem, among them using gramian-based measures, which include the Hankel interaction index array, the participation matrix and the (Formula presented.) method. The gramian-based measures, however, have issues with input and output scaling. Generally, this is resolved by scaling all inputs and outputs to have equal range. However, we demonstrate how this can result in an incorrect pairing and examine alternative methods of scaling the gramian-based measures, using either row or column sums or by utilising the Sinkhorn-Knopp algorithm. To systematically analyse the benefits of the scaling schemes, a multiple-input multiple-output model generator is used to test the different schemes on a large number of systems. This assessment shows considerable benefits to be gained from the alternative scaling of the gramian-based measures, especially when using the Sinkhorn-Knopp algorithm
A framework for flexible and cost-efficient retrofit measures of heat exchanger networks
Retrofitting of industrial heat recovery systems can contribute significantly to meeting energy efficiency targets for industrial plants. One issue to consider when screening retrofit design proposals is that industrial heat recovery systems must be able to handle variations, e.g., in inlet temperatures or heat capacity flow rates, in such a way that operational targets are reached. Consequently, there is a need for systematic retrofitting methodologies that are applicable to multiperiod heat exchanger networks (HENs). In this study, a framework was developed to achieve flexible and cost-efficient retrofit measures of (industrial) HENs. The main idea is to split the retrofitting processes into several sub-steps. This splitting allows well-proven (single period) retrofit methodologies to be used to generate different design proposals, which are collected in a superstructure. By means of structural feasibility assessment, structurally infeasible design proposals can be discarded from further analysis, yielding a reduced superstructure. Additionally, critical point analysis is applied to identify those operating points within the uncertainty span that determine necessary overdesign of heat exchangers. In the final step, the most cost-efficient design proposal within the reduced superstructure is identified. The proposed framework was applied to a HEN retrofit case study to illustrate the proposed framework
Potential for Negative Emissions by Carbon Capture and Storage From a Novel Electric Plasma Calcination Process for Pulp and Paper Mills
The pulp and paper industry has a high potential to contribute to negative emissions through carbon capture and storage (CCS) applied to existing processes. However, there is a need to investigate how CCS solutions also can be combined with implementation of other emerging technologies in pulp and paper mills. This paper investigates the integration of a novel calcination process in two kraft mills and evaluates its potential combination with capture and storage of CO2\ua0from the calcination plant. The alternative calcination process uses electric gas-plasma technology combined with steam slaking and allows replacing the conventional fuel-driven lime kilns with a process driven by electricity. The novel calcination process generates a pure, biogenic, CO2\ua0stream, which provides an opportunity to achieve negative emissions at relatively lower costs. The potential reduction of greenhouse gas emissions when replacing the lime kiln with the plasma calcination concept depends strongly on the emissions intensity of grid electricity, and on whether fossil fuel or biomass was used as a fuel in the lime kiln. If fossil fuel is replaced and electricity is associated with very low emissions, avoided CO2\ua0emissions reach ~50 kt/a for the smaller mill investigated in the paper (ca 400 kt pulp per year) and almost 100 kt/a for the larger mill (ca 700 kt pulp per year). Further emission reductions could then be achieved through CCS from the electrified calcination process, with capture potentials for the two mills of 95 and 164 kt/a, respectively, and capture and storage costs estimated to 36â60 EUR/tCO2
Medborgarforskning
Denna litteraturstudie handlar om begreppet citizen science, pÄ svenska kallat medborgarforskning. Genom att involvera medborgare i forskningsprojekt finns flera positiva effekter att uppnÄ. Det har visat sig att forskningens resultat sÀllan kommer till allmÀnhetens kÀnnedom och fÄr en praktisk förankring. Det har Àven framkommit att lokala kunskaper och engagemang inte blir dokumenterade eller bekrÀftade. Med hjÀlp av medborgarforskning ska fler kunna skapa sig mer kÀnnedom inom forskningsprojekt och vara delaktiga i att samla vetenskaplig information över lÀngre tidsperioder.
I denna litteraturstudie kopplas medborgarforskning till urbana trÀd och det strÀvsamma arbetet att kartlÀgga dem i stÀder. Inventeringar Àr en stÀndigt pÄgÄende process som ligger till grund för beslutsfattande, prioriteringar, ekonomisk- och ekologisk vÀrdering samt planering hos förvaltningarna som sköter dem. Genom att ta hjÀlp av allmÀnheten kan ett vakande öga över stadens vegetation skapas.
Tack vare dagens teknik finns praktiska hjÀlpmedel som applikationer och hemsidor. Dessa kan lokalisera trÀden och skapa spÀnnande mötesplatser för personer med samma intresse för miljön. Detta kan vara en lösning pÄ en allt mer segregerad urbanisering med följder sÄsom psykisk ohÀlsa och miljöförstöring. Möten och informationsspridning mellan mÀnniskor i nÀromrÄdet och över landsgrÀnser kan skapas med hjÀlp av den virtuella vÀrlden
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