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This study proposes the experimental evaluation of alternative refrigerants with low global warming potentials (GWPs) such as R1234ze(E), R513A, and the mixture R516A as a drop-in replacement for R134a in a domestic refrigerator with a volumetric capacity of 513 L. Initially, the optimal charge for each refrigerant was defined based on the minimum energy consumption of the refrigerator, then the thermal and energy performance of the refrigerator was evaluated. Finally, a total equivalent warming impact analysis (TEWI) was performed. The main results indicated that the optimal charge of the alternative refrigerants was below that corresponding to R134a (105 g), of which R516A (86 g) presented the greatest charge reduction. Regarding the average temperature of the refrigerator compartments, very adequate thermal conditions were observed; thus, the alternative refrigerants showed very similar conditions to R134a. For the coefficient of performance (COP) and considering R134a as a reference, it was observed that R513A presented the greatest reduction of around 28%, while R1234ze(E) showed an increase of 13% in relation to R134a. Finally, the TEWI analysis showed R1234ze(E) as the refrigerant with the least impact. [ABSTRACT FROM AUTHOR]

• R513A showed a 9% reduction in energy consumption compared to R134a. • The TEWI for R513A presented a reduction of 8.85% with respect to R134a. • The optimal charge of R513A presented a reduction of 16.7% with respect to R134a. Today, hydrofluorocarbons continue to be used as part of a long transition towards the use of fluids with less impact on the environment. In this sense, the present work provides more information on the thermal and energetic performance of a domestic refrigerator using the R513A refrigerant as a direct replacement for R134a. Initially, the effect of the variation of the R513A charge on certain parameters such as operating pressures and temperatures, the superheating degree and subcooling, as well as the cooling capacity, is evaluated. The charge variations were made in increments of 10 g, until the optimal charge was defined for R513A concerning the minimum energy consumption, which was 100 g, representing a reduction of 16.7% compared to R134a (120 g). Once the optimal charge was defined, comparisons were made between both refrigerants under the same test conditions, resulting in a very similar average temperature of the refrigerator compartments; and for a test period of 24 h, R513A showed a 9% reduction in energy consumption compared to R134a. Finally, the analysis of the total equivalent warming impact presented R513A as a fluid with a lesser impact, around 8.85%, relative to R134a. [ABSTRACT FROM AUTHOR]

Abstract This experimental study evaluates the energy performance and climatic changes of a cascade cooling system operating with the R134a/R744 pairs (cooling capacity of 4.5‐6 kW) and R438A/R744. In both cases, the low‐temperature refrigerant, R744, operated under subcritical conditions. The experimental apparatus basically consists of two vapor‐compression cycles coupled by a plate cascade condenser. Two operational variables, from R744 cycle, were controlled: the degree‐of‐superheat and the compressor frequency. The experiment was initially assembled to pair R134a/R744. Subsequently, the R134a refrigerant charge in the high‐temperature cycle was replaced by R438A, on a drop‐in basis. The two systems, R134a/R744 and R438A/R744, were compared for similar cooling capacities and cold chamber air temperatures. Results showed that the energy consumption of the high‐temperature compressor, operating with R438A, was higher than R134a for all tests. As a result, the COP values for R438A/R744 were 30% lower than those for R134a/R744. The greenhouse gases emissions of the two systems were evaluated using the total equivalent warming impact factor, TEWI, whose value for the R438A/R744 pair was approximately 29.5% higher, compared with R134a/R744. Since R438A was originally designed to substitute R22, a few comparative tests were carried out with the latter, always with R744 as the low‐temperature cycle working fluid.

This study proposes the experimental evaluation of alternative refrigerants with low global warming potentials (GWPs) such as R1234ze(E), R513A, and the mixture R516A as a drop-in replacement for R134a in a domestic refrigerator with a volumetric capacity of 513 L. Initially, the optimal charge for each refrigerant was defined based on the minimum energy consumption of the refrigerator, then the thermal and energy performance of the refrigerator was evaluated. Finally, a total equivalent warming impact analysis (TEWI) was performed. The main results indicated that the optimal charge of the alternative refrigerants was below that corresponding to R134a (105 g), of which R516A (86 g) presented the greatest charge reduction. Regarding the average temperature of the refrigerator compartments, very adequate thermal conditions were observed; thus, the alternative refrigerants showed very similar conditions to R134a. For the coefficient of performance (COP) and considering R134a as a reference, it was observed that R513A presented the greatest reduction of around 28%, while R1234ze(E) showed an increase of 13% in relation to R134a. Finally, the TEWI analysis showed R1234ze(E) as the refrigerant with the least impact.

The aviation sector seeks to reduce greenhouse gas (GHG) emissions, with manufacturers and airlines announcing “zero-emission” goals and plans. Reduced carbon aviation fuels are central to meeting these goals. However, current and near-term aircraft, which will remain flying for decades, are designed around the combustion of petroleum-based aviation kerosene (e.g., Jet A/A-1). Therefore, the industry has focused on the qualification and approval of synthesized (e.g., non-petroleum-based) aviation fuel components with maximum blend limit percentages to avoid the blended fuel having properties outside the accepted ranges for Jet A/A-1. The synthesized components approved for blending are not necessarily interchangeable with Jet A/A-1. They may lack certain required chemical components, such as aromatics, or may have other characteristics outside the allowable ranges. To ensure safety, these synthesized aviation fuel components are only qualified to be used in commercial aviation when blended up to approved limits. The sector seeks to move toward the capability of using 100% synthesized aviation fuels that also meet sustainability criteria, known as sustainable aviation fuels, or SAF. However, these fuels must be developed, assessed, and deployed appropriately. This paper explores key questions relating to the introduction of 100% SAF, concluding that:• Near-term unblended synthesized aviation fuels must be “drop-in,” meaning they are compatible with existing aircraft and infrastructure.• Stand-alone complete fuels could be qualified within 1–2 years, with blends of blending components to reach 100% synthesized fuels to follow.• Sustainability criteria, while critical to sector acceptance, will continue to be assessed separately from technical performance.

This experimental study evaluates the energy performance and climatic changes of a cascade cooling system operating with the R134a/R744 pairs (cooling capacity of 4.5‐6 kW) and R438A/R744. In both cases, the low‐temperature refrigerant, R744, operated under subcritical conditions. The experimental apparatus basically consists of two vapor‐compression cycles coupled by a plate cascade condenser. Two operational variables, from R744 cycle, were controlled: the degree‐of‐superheat and the compressor frequency. The experiment was initially assembled to pair R134a/R744. Subsequently, the R134a refrigerant charge in the high‐temperature cycle was replaced by R438A, on a drop‐in basis. The two systems, R134a/R744 and R438A/R744, were compared for similar cooling capacities and cold chamber air temperatures. Results showed that the energy consumption of the high‐temperature compressor, operating with R438A, was higher than R134a for all tests. As a result, the COP values for R438A/R744 were 30% lower than those for R134a/R744. The greenhouse gases emissions of the two systems were evaluated using the total equivalent warming impact factor, TEWI, whose value for the R438A/R744 pair was approximately 29.5% higher, compared with R134a/R744. Since R438A was originally designed to substitute R22, a few comparative tests were carried out with the latter, always with R744 as the low‐temperature cycle working fluid. [ABSTRACT FROM AUTHOR]

According to the EU F-gas Regulation, the phase-out of the high global warming potential (GWP) refrigerants (with higher than 150 GWP value) had been established. The most currently existing household and commercial refrigerators and automobile air conditioners applications based on single-stage vapour compression systems operate with R134a as working fluid. The present paper aims, to review and evaluate the performance of a set of eco-friendly alternatives refrigerants to replace R134a, without change or with minor modifications in refrigeration equipment. The theoretical and experimental studies performed in this field of research were reviewed for this objective. These alternative refrigerants are some of HFCs, HFOs and HCs and their mixtures, which are expected to be an excellent candidates in many refrigeration applications. There are Many replacement possibilities had been proposed viz. drop-in replacement, retrofit refrigerant, and new systems. The results exhibited that the most suitable refrigerants as R134a drop-in substitutes are R1234yf, R152a, R450A, and R513A. The pure R1234ze and its mixtures are not suitable drop-in replacements of R134a but can be a good alternative to R134a only in new refrigeration systems. In terms of hydrocarbon refrigerants R290, R600, and R600a could replace R134a with some modifications to existing refrigeration systems to overcome the flammability issue. We should be using certain HFC and HC mixtures with the lowest TEWI index. [ABSTRACT FROM AUTHOR]

Abstract Background Children with chronic health conditions and their parents are at greater risk of developing emotional and behavioural problems compared to their physically healthy peers. The psychological impact on parents is crucial to understand given the relationship between parental mental health and child emotional and behavioural difficulties. This study was part of a broader research project examining the acceptability, feasibility and impact of a ‘Mental Health and Psychological Wellbeing Drop‐in Centre’ in a paediatric hospital providing access to support and intervention for children and their families. This paper aimed to investigate the impact of the centre on parents (n = 148). Methods Parental anxiety and depression were assessed using the GAD‐7 and PHQ‐9 at baseline and 6‐month post‐baseline. Child mental health was assessed using the parent‐report Strengths and Difficulties Questionnaire (SDQ). If parents had significant mental health needs, a brief intervention/signposting to relevant services was provided. Results At baseline, 48% of parents scored above clinical threshold for anxiety and 41% for depression, and parent reported child SDQ scores were correlated with parental anxiety and parental low mood. Self‐reported parental anxiety and low mood decreased at 6‐months post‐baseline (parental anxiety: mean decrease = 2.29 [1.22–3.36], d = 0.38; parental low mood: mean decrease = 1.81 [0.64–3.00], d = 0.28). There were no significant correlations between change in parent reported child wellbeing and changes in parental low mood and anxiety between baseline and 6‐month post‐baseline. Conclusions Assessing and providing a brief treatment to address the mental health needs of parents of children with comorbidity may bring important benefits. It is recommended that children's mental health services consider assessment of parental mental health as part of routine care.

• First experimental work using R468A in a vapour compression cycle, mounting a low temperature freezing cabinet. • Energy consumption is similar using R404A or R468A • R468A is a proper energy alternative to R404A. • No technical problems arise. • IHX is useful to improve energy consumption when R468A is used as working fluid. This work analyses experimentally the energy behaviour of a centralized commercial refrigeration plant designed to be used with R404A (GWP 100 = 3,943) at low temperatures, when it is replaced with the new low-GWP refrigerant blend R468A (GPW 100 = 148). The tests have been done at a selected product temperature of -20°C, Class III indoor conditions according to ISO 23953-2:2015 and 20, 30 and 40°C of heat sink temperature. The product has been kept at the requested temperature in whichever conditions tested. Respect to R404A, running with R468A presents an increase in compressor discharge temperature, greater compressión operation time, and a reduction in compressor electric comssumption that yields in a very similar total energy consumption of the refrigeration plant. So it has been proved that, from an operational point of view, R468A can be a R404A drop in replacement fluid. Also, it has been measured energy savings when an internal heat exchanger is placed. [ABSTRACT FROM AUTHOR]

• A drop-in replacement of R-134a with R-152a in a domestic refrigerator was performed. • The energy performance of the system was improved with R-152a. • An environmental impact assessment was carried out by TEWI and LCCP approaches. • Both environmental metrics showed great environmental benefits with R-152a. • The effect of carbon intensity variation on LCCP was investigated. In the European Union F-gas Regulation limited the use of some refrigerants in several applications. Regarding the domestic refrigeration sector, the F-gas Regulation banned the use of refrigerants with GWP values higher than 150. This fact led the scientific community to search for a replacement of R-134a, that is the most common refrigerant used in domestic refrigerators in USA. In this work, a comprehensive environmental analysis of the drop-in substitution of R-134 with a low GWP refrigerant (R-152a) in a no-frost domestic refrigerator was performed. The comparison, based on experimental data, between the environmental performance of the refrigeration system with the two refrigerants was carried out developing two different evaluation methods, which led to the evaluation of TEWI and LCCP, respectively. Both these metrics consider both direct and indirect contributions to global warming. Historical data of different countries were used to forecast the carbon intensity values for the next 15 years, which were then used to evaluate indirect emissions of the system during its lifetime. Considering the Italian case study, the results showed that the refrigerator working with an optimal charge of R-152a, identified as the mass charge that minimises TEWI and/or LCCP index, has better environmental performance than the system working with R-134a, with a reduction of TEWI and LCCP values of 10.3% and 9.4%, respectively. The same comparison, in terms of LCCP, was also performed for other European countries, showing a strong dependence of the LCCP index on carbon intensity values. [ABSTRACT FROM AUTHOR]

We previously reported a CRISPR-mediated knock-in strategy into introns of Drosophila genes, generating an attP-FRT-SA-T2A-GAL4-polyA-3XP3-EGFP-FRT-attP transgenic library for multiple uses (Lee et al., 2018a). The method relied on double stranded DNA (dsDNA) homology donors with ~1 kb homology arms. Here, we describe three new simpler ways to edit genes in flies. We create single stranded DNA (ssDNA) donors using PCR and add 100 nt of homology on each side of an integration cassette, followed by enzymatic removal of one strand. Using this method, we generated GFP-tagged proteins that mark organelles in S2 cells. We then describe two dsDNA methods using cheap synthesized donors flanked by 100 nt homology arms and gRNA target sites cloned into a plasmid. Upon injection, donor DNA (1 to 5 kb) is released from the plasmid by Cas9. The cassette integrates efficiently and precisely in vivo. The approach is fast, cheap, and scalable.

Background: The COVID-19 pandemic exerted extraordinary pressure on health care workers (HCWs), imperiling their well-being and mental health. In response to the urgent demand to provide barrier-free support for the health care workforce, Pause-4-Providers implemented 30-minute live web-based drop-in mindfulness sessions for HCWs., Objective: This study aims to evaluate the use, feasibility, satisfaction, and acceptability of a novel mindfulness program aimed at enhancing the well-being of HCWs during the COVID-19 pandemic., Methods: Accrual for the study continued throughout the first 3 pandemic waves, and attendees of ≥1 session were invited to participate. The evaluation framework included descriptive characteristics, including participant demographics, resilience at work, and single-item burnout scores; feedback questionnaires on reasons attended, benefits, and satisfaction; qualitative interviews to further understand participant experience, satisfaction, benefits, enablers, and barriers; and the number of participants in each session summarized according to the pandemic wave., Results: We collected descriptive statistics from 50 consenting HCWs. Approximately half of the participants (24/50, 48%) attended >1 session. The study participants were predominantly female individuals (40/50, 80%) and comprised physicians (17/50, 34%), nurses (9/50, 18%), and other HCWs (24/50, 48%), who were largely from Ontario (41/50, 82%). Of 50 attendees, 26 (52%) endorsed feeling burned out. The highest attendance was in May 2020 and January 2021, corresponding to the first and second pandemic waves. The participants endorsed high levels of satisfaction (43/47, 92%). The most cited reasons for attending the program were to relax (38/48, 79%), manage stress or anxiety (36/48, 75%), wish for loving kindness or self-compassion (30/48, 64%), learn mindfulness (30/48, 64%), and seek help with emotional reactivity (25/48, 53%). Qualitative interviews with 15 out of 50 (30%) participants identified positive personal and professional impacts. Personal impacts revealed that participation helped HCWs to relax, manage stress, care for themselves, sleep better, reduce isolation, and feel recognized. Professional impacts included having a toolbox of mindfulness techniques, using mindfulness moments, and being calmer at work. Some participants noted that they shared techniques with their colleagues. The reported barriers included participants' needing time to prioritize themselves, fatigue, forgetting to apply skills on the job, and finding a private place to participate., Conclusions: The Pause-4-Providers participants reported that the web-based groups were accessible; appreciated the format, content, and faculty; and had high levels of satisfaction with the program. Both novel format (eg, drop-in, live, web-based, anonymous, brief, and shared activity with other HCWs) and content (eg, themed mindfulness practices including micropractices, with workplace applications) were enablers to participation. This study of HCW support sessions was limited by the low number of consenting participants and the rolling enrollment project design; however, the findings suggest that a drop-in web-based mindfulness program has the potential to support the well-being of HCWs., (©Mary Elliott, Camille Khallouf, Jennifer Hirsch, Diane de Camps Meschino, Orit Zamir, Paula Ravitz. Originally published in JMIR Formative Research (https://formative.jmir.org), 14.03.2024.)

Targeting faculties and external mentors in the teacher-training unit, The Norwegian University of Science and Technology in Trondheim, Norway opened up a Massive Open Online Course (MOOC) pilot on digital learning in the fall of 2014. A main objective was to encourage these to use digital media more actively and hence, also to become role models for their own students' future digital practice. However, research has shown that a main concern with MOOC programs is attrition. In line with those findings, and according to the course platform data, none of the MOOC participants completed the course material. As the course progressed, less and less pages were opened and obligatory assignments were only rarely submitted. The participants may thus be described as dropouts. Five of these participants were then interviewed about their MOOC experiences and activities. The interviews were transcribed and analyzed according to Grounded theory procedures. A general finding was that the informants would in fact put some of the material and ideas from the MOOC to use. Even if they dropped out, this indicates a gain from the course. In fact, some of the material that was introduced significantly changed these informants' digital practices when they tested out new ideas in their own teaching. Frame-factors, such as lack of financial compensation or a nonstop flow of competing tasks, however, led the informants to down-prioritize the formal demands in the MOOC pilot. The informants selectively picked the material that suited their own purpose and therefore qualified as "drop-ins" rather than "drop-outs". Rather than quitters who could not keep up with the pace in the MOOC we met media literate participants who remixed and redefined the MOOC content into a Web 2.0 resource and a stepping stone for self-directed online learning. [ABSTRACT FROM AUTHOR]

Abstract In this work, the use of R1234yf as a drop-in replacement for R134a in an air to water refrigeration system used to produce cool water at 7 °C is studied. This equipment was constructed in our laboratory with a minichannel heat exchanger working as condenser and a plate heat exchanger working as evaporator resulting in a 2.5 kW water chiller, which initially was working with R134a as refrigerant. A brief description of the refrigeration system and the installation used to test its behaviour as well as the uncertainty analysis is presented. Then, the test matrix defined in order to evaluate the effect of the different variables of interest on the performance of the refrigeration cycle is also presented. Air inlet temperature in the condenser was varied in order to analyse the influence of a variation in the ambient temperature. Other variables were varied in order to analyse the influence of different operating conditions as a variation in the compressor frequency or in the condenser fan velocity (by varying air inlet velocity). Finally, the subcooling degree was varied in order to compare a system with refrigerant receiver (no subcooling) and a system without refrigerant receiver and different refrigerant charge (different subcooling). According to the results obtained, R1234yf performs worse than R134a, presenting lower cooling capacity and higher compressor consumption in all tests, with a global efficiency around 25% lower. This can be explained by its lower isentropic and volumetric efficiency, which could be related to the type of lubricant used. [ABSTRACT FROM AUTHOR]

In this work, the alternative refrigerants were evaluated as a drop-in of an R-22-based refrigeration system. The tested system comprises a variable-speed scroll compressor, an electronic expansion valve, a hot-and-cold water circuit and their respective heat exchangers. To make a fair comparison among fluids, only the lubricant type and refrigerant charge were varied to ensure good system functionality. The system performance was evaluated, varying the expansion valve opening to achieve evaporation temperatures of −5 °C, −10 °C and −15 °C. The same methodology was applied for various frequencies using an inverter drive. It was carried out in more than 200 experiments, and the response surface method was used to analyze the results. For all tested conditions, the R-438A was the most flexible alternative among the tested refrigerants as a drop-in of R-22 operating with a scroll compressor since the system operated in a wider range of values. Meanwhile, the R-1270 had the highest cooling capacity value and the lowest TEWI. [ABSTRACT FROM AUTHOR]

This paper presents an experimental study for three identical domestic refrigerators using R1234yf as a drop-in replacement for R134a. An alternative methodology was proposed to estimate the optimal mass charge for R1234yf; with the use of such methodology, new evidences were sought on the thermal behavior of the refrigerator compartments as well as at the heat exchangers. Additionally, energy performance for both refrigerants was measured, and, finally, a TEWI analysis was conducted. For the type of refrigerator evaluated, results showed that R1234yf presented an average (for the 3 refrigerators) of 0.4 °C for the fresh food compartment, and 1.2 °C for the freezer, among different charges with respect to R134a. The optimal charge for R1234yf was 92.2 g, which is about 7.8% lower than the one for R134a, which represents a small increase of 4% in energy consumption in comparison to R134a. Finally, the TEWI analysis for the R1234yf was 1.07% higher than the R134a. [ABSTRACT FROM AUTHOR]

There is a need to understand the occurrence of drop-in and their peak height distributions to further improve existing models to interpret complex DNA results. The necessary data is usually very time-consuming to collect. Here we present a practical approach for simultaneous characterisation of reproducible artefacts and drop-in contamination from negative controls. As an alternative to the traditional approach we demonstrate the use of the DEPArray system as a source of single molecules for amplification to infer the peak height distribution of drop-in events. Though signal detection is often confounded by noise and artefact, single molecule contamination, or allele drop-in, is also regularly detected as demonstrated by the overlap in signal intensities between suspected drop-in events and signal obtained from single-cells. [ABSTRACT FROM AUTHOR]

This work analyses experimentally the possibility of using the reduced GWP refrigerant R-407H (HFC family, GWP = 1378) as drop-in substitute of R-404A (HFC family, GWP = 3945) in low temperature centralized direct expansion refrigeration system. The experimental plant and the test methodology are described. It covered top up or partial drop-in and energy consumption tests at −20 °C of product temperature and 25, 35 and 45 °C of condensing temperature using a small-scale supermarket under laboratory conditions. It has been measured that the use of R-407H instead of R-404A is favourable from the point of view of energy efficiency. Reductions in the energy consumption of up to 7.7% (compressor) and 4.0% (whole system) have been measured. However, there is an increment in the compressor's discharge temperature of up to 13.8 K. In addition, the operation of the system with both refrigerants was correct. [ABSTRACT FROM AUTHOR]

We present a general method for analysing DNA mixtures involving relatives that accounts for dropout and drop-in, mutations, silent alleles and population substructure. Whether the aim is to identify the contributors to a mixture who may be related, or to determine the relationship between individuals based on a DNA mixture, both types of problems can be handled by the method and software presented here. We focus on the latter scenario, motivated by non-invasive prenatal paternity testing where the profile of the child is available only in the form of a mixture with the mother's profile. Relationships are represented by pedigrees and can include kinship between more than two individuals. The software is freely available as a graphical user interface in the R package relMix. [ABSTRACT FROM AUTHOR]

Day shelter programs are an important resource for people experiencing homelessness, offering respite from inclement weather, social stigma, victimization, and access to essential services and resources. Creating functional day shelter spaces requires that staff, services, and facilities support the needs of this vulnerable and marginalized population. Little guidance, however, is available regarding the design of day shelter spaces that support service engagement and positive service outcomes. This systematic review was conducted to support the development of a new day shelter in Fort Worth, Texas, identifying and reviewing interdisciplinary resources relevant to the design of these facilities. Based on the review, a preliminary taxonomy emphasizing day shelter client safety, security, dignity and health and well-being is proposed. Additional discussion identifies practical considerations affecting the implementation of the taxonomy, design priorities, and how the taxonomy was applied to the design of the Fort Worth day shelter. [ABSTRACT FROM PUBLISHER]

In this paper are reported the results of an experimental comparative analysis between R134a and HFO1234ze, when they are employed as refrigerants in a domestic refrigerator. Under sub-tropical conditions, it have been measured the energy consumptions in accordance with the UNI-EN-ISO15502. For each experiment it have been estimated both the TEWI and the Life Cycle Climate Performance indexes to assess the environmental impact due to HFO1234ze when used in place of R134a. [ABSTRACT FROM AUTHOR]

This paper presents an experimental investigation of the drop-in process for HCFC-22 in a 5-ton refrigeration system. The original refrigerant was replaced by alternative halogenated refrigerants such as HFC-438A, HFC-404A, HFC-410A and HFC-32, as well as hydrocarbons HC-290 and HC-1270. The experimental facility was composed basically of a semi-hermetic reciprocating compressor, tube in tube heat exchangers and an electronic expansion valve. The tests were performed by just replacing the refrigerant, without changing any components, typically as in a drop-in process. The main parameters were varied to verify the range and performance of each refrigerant and then compared to the HCFC-22. Results showed that the natural refrigerants presented the best coefficient of performance and that results for HFCs, excepting the HFC-32, remained below those of HCFC-22. Regarding the environmental impact, using the parameter TEWI, the best results were reached with hydrocarbons; meanwhile, the refrigerant HFC-404A presented the highest environmental impact. [ABSTRACT FROM AUTHOR]

The R22 refrigerant widely used in refrigerating and air conditioning devices is invariably released to the atmosphere due to reasons such as breakdown and/or translocation. As the sales of new devices operating with R22 are decreasing gradually, refrigerants of such available devices should be changed with the ones that are not depleting the ozone layer. In this paper, the amount of consumed energy, cooling capacity and COP values of R417A, R422A, R422D and R424A, which can be used as alternatives to R22, were determined experimentally for a split type air conditioning device at the ambient temperatures of 35, 38 and 41 °C. Basically, COP values of all HFC refrigerants were found to be smaller than that of R22. It was noted that the most suitable refrigerating fluid was R424A, which can be used instead of R22, since the COP of R424A was smaller than that of R22 by 2.5% only at an ambient temperature of 41 °C. [ABSTRACT FROM AUTHOR]

[Display omitted] • Biofuels are necessary to mitigate the climate impacts in the EU maritime transport. • Impacts of biofuels are heavily dependent on countries' electricity mixes. • Without carbon capture, synthetic natural gas has the highest mitigation potential. • Among carbon-free biofuels, bio-ammonia has the highest mitigation potential. • By 2050, bio-hydrogen can provide the lowest emissions per unit of energy. Alternative fuels are crucial to decarbonize the European maritime transport, but their net climate benefits vary with the type of fuel and production country. In this study, we assess the energy potential and climate change mitigation benefits of using agricultural and forest residues in different European countries for drop-in (Fast Pyrolysis, Hydrothermal Liquefaction, and Gasification to Fischer-Tropsch fuels or Bio-Synthetic Natural Gas) and hydrogen-based biofuels (hydrogen, ammonia, and methanol) with or without carbon capture and storage (CCS). Our results show the combinations of countries and biofuel options that successfully achieve the decarbonization targets set by the FuelEU Maritime initiative for the next years, including a prospective analysis that include technological changes projected for the biofuel supply chains until 2050. With the current technologies, the largest greenhouse gas (GHG) mitigation potential per year at a European scale is obtained with bio-synthetic natural gas and hydrothermal liquefaction. Among carbon-free biofuels, ammonia currently has higher mitigation, but hydrogen can achieve a lower GHG intensity per unit of energy with the projected decarbonization of the electricity mixes until 2050. The full deployment of CCS can further accelerate the decarbonization of the maritime sector. Choosing the most suitable renewable fuels requires a regional perspective and a transition roadmap where countries coordinate actions to meet ambitious climate targets. [ABSTRACT FROM AUTHOR]

To Prof. Jürgen Köhler to his 60th birthday. ORCs (Organic Rankine Cycle) experience growing interest for the generation of electricity from industrial waste heat. However, the widely used working fluid R-245fa does not seem to be sustainable due to its relative high GWP (Global Warming Potential) of almost 900 [1]. In this work, we have evaluated the low GWP working fluid R-1234ze(Z) as drop-in replacement for R-245fa in low-grade ORC processes. Our studies thereby comprise a comparison of the thermophysical properties of R-1234ze(Z) and R-245fa and resulting differences in the performance of the ORC cycle. Information on the thermophysical properties of R-1234ze(Z) from experiment is complemented by molecular simulation results. Our system simulation studies on the ORC process covers a heat source temperature range from 100 °C to 250 °C, which represents relevant operating conditions for industrial applications. A stationary cycle model of a typical ORC configuration was set up in order to optimize operation points and to evaluate characteristic system values for both working fluids. Our simulation results indicate that R-1234ze(Z) is a promising replacement fluid for R-245fa in ORC applications, though noticeable performance losses for heat source temperatures between 183 and 224 °C are observed. [ABSTRACT FROM AUTHOR]

Due to the adoption of EU Regulation No 517/2014, R404A is going to be banned in Europe in most of refrigeration applications, in which is typically used, due to its very high GWP value, 3943. In this paper an experimental comparison between R404A and R448A, a non-flammable alternative with GWP of 1390, is presented. The experimental tests are intended to simulate typical freezing and conservation temperatures and different condensing conditions. Despite cooling capacity of R448A is slightly below that of R404A, R448A energy consumption is even smaller; and R448A COP is higher than that obtained using R404A. Hence, it can be concluded that R448A could be an energy efficient alternative to R404A with a GWP reduction of 70%. Compressor discharge temperature remains at non-dangerous levels. [ABSTRACT FROM AUTHOR]

The interpretation of mixed DNA profiles obtained from low template DNA samples has proven to be a particularly difficult task in forensic casework. Newly developed likelihood ratio (LR) models that account for PCR-related stochastic effects, such as allelic drop-out, drop-in and stutters, have enabled the analysis of complex cases that would otherwise have been reported as inconclusive. In such samples, there are uncertainties about the number of contributors, and the correct sets of propositions to consider. Using experimental samples, where the genotypes of the donors are known, we evaluated the feasibility and the relevance of the interpretation of high order mixtures, of three, four and five donors. The relative risks of analyzing high order mixtures of three, four, and five donors, were established by comparison of a ‘gold standard’ LR, to the LR that would be obtained in casework. The ‘gold standard’ LR is the ideal LR: since the genotypes and number of contributors are known, it follows that the parameters needed to compute the LR can be determined per contributor. The ‘casework LR’ was calculated as used in standard practice, where unknown donors are assumed; the parameters were estimated from the available data. Both LRs were calculated using the basic standard model, also termed the drop-out/drop-in model, implemented in the LRmix module of the R package Forensim . We show how our results furthered the understanding of the relevance of analyzing high order mixtures in a forensic context. Limitations are highlighted, and it is illustrated how our study serves as a guide to implement likelihood ratio interpretation of complex DNA profiles in forensic casework. [ABSTRACT FROM AUTHOR]

This work presents an experimental analysis of a non-flammable R1234ze(E)/R134a mixture (R450A) as R134a drop-in replacement. While R134a has a high GWP value (1430), the R450A GWP is only 547. The experimental tests are carried out in a vapour compression plant equipped with a variable-speed compressor. The replacement suitability has been studied combining different operating conditions: evaporation temperature, condensation temperature and the use of an internal heat exchanger (IHX). The drop-in cooling capacity of R450A compared with R134a is 6% lower as average. R450A COP is even higher to those resulting with R134a (approximately 1%). The discharge temperature of R450A is lower than that of R134a, 2K as average. The IHX has a similar positive influence on the energy performance of both fluids. In conclusion, R450A can be considered as a good candidate to replace R134a. [ABSTRACT FROM AUTHOR]

Abstract: There has been very little work published on the variation of reporting practices of mixtures between laboratories, but it has been previously demonstrated that there is little consistency. This is because there is no current uniformity of practice, so different laboratories will operate using different rules. The interpretation of mixtures is not solely a matter of using some software to provide ‘an answer’. An assessment of a case will usually begin with a consideration of the circumstances of a crime. Assumptions made about the numbers of contributors follow from an examination of the electropherogram(s) – and these may differ between the prosecution and the defence hypotheses. There may be a necessity to evaluate several sets of hypotheses for any given case if the circumstances are uncertain. Once the hypotheses are formulated, the mathematical analysis is complex and can only be accomplished by the use of specialist software. In order to obtain meaningful results, it is essential that scientists are trained, not only in the use of the software, but also in the methodology to understand the likelihood ratio concept that is used. The Euroforgen-NoE initiative has developed a training course that utilizes the LRmix program to carry out the calculations. This software encompasses the recommendations of the ISFG DNA commissions on mixture interpretation and is able to interpret samples that may come from two or more contributors and may also be partial profiles. Recently, eighteen different laboratories were trained in the methodology. Afterwards they were asked to independently analyze two different cases with partial mixture DNA evidence and to write a statement court-report. We show that by introducing a structured training programme, it is possible to demonstrate, for the first time, that a high degree of standardization, leading to uniformity of results can be achieved by participating laboratories. [Copyright &y& Elsevier]

Abstract: This paper presents an experimental analysis of a vapor compression system using R1234yf as a drop-in replacement for R134a. In this work, we compare the energy performance of both refrigerants, R134a and R1234yf, in a monitored vapor compression system under a wide range of working conditions. So, the experimental tests are carried out varying the condensing temperature, the evaporating temperature, the superheating degree, the compressor speed, and the internal heat exchanger use. Comparisons are made taking refrigerant R134a as baseline, and the results show that the cooling capacity obtained with R1234yf in a R134a vapor compression system is about 9% lower than that obtained with R134a in the studied range. Also, when using R1234yf, the system shows values of COP about 19% lower than those obtained using R134a, being the minor difference for higher condensing temperatures. Finally, using an internal heat exchanger these differences in the energy performance are significantly reduced. [Copyright &y& Elsevier]

Abstract: The interpretation of DNA mixtures has proven to be a complex problem in forensic genetics. In particular, low template DNA samples, where alleles can be missing (allele drop-out), or where alleles unrelated to the crime-sample are amplified (allele drop-in), cannot be analysed with classical approaches such as random man not excluded or random match probability. Drop-out, drop-in, stutters and other PCR-related stochastic effects, create uncertainty about the composition of the crime-sample, making it difficult to attach a weight of evidence when (a) reference sample(s) is (are) compared to the crime-sample. In this paper, we use a probabilistic model to calculate likelihood ratios when there is uncertainty about the composition of the crime-sample. This model is essentially exploratory in the sense that it allows the exploration of LRs when two key-parameters, drop-out and drop-in are varied within their plausible ranges of variation. We build on the work of Curran et al. [8], and improve their probabilistic model to allow more flexibility in the way the model parameters are applied. Two new main modifications are brought to their model: (i) different drop-out probabilities can be applied to different contributors, and (ii) different parameters can be used under the prosecution and the defence hypotheses. We illustrate how the LRs can be explored when the drop-out and drop-in parameters are varied, and suggest the use of Monte Carlo simulations to derive plausible ranges for the probability of drop-out. Although the model is suited for both high and low template samples, we illustrate the advantages of the exploratory approach through two DNA mixtures (involving two and at least three individuals) with low template components. [Copyright &y& Elsevier]

Abstract: DNA typing protocols have been improved over the last few years and even mixtures from minute and low grade DNA stains do not necessarily preclude typing. Nevertheless, in those cases stochastic phenomena tend to hamper interpretation. In order to supplement the current discussion about the interpretation of such challenging data, we focused on different combinations of analyses as an attempt to overcome stochastic problems. We analyzed mixtures of two types of degraded DNA in low template amounts (50 and 100pg DNA per contributor) using four types of multiplex STR typing kits: PowerPlex® ESX 17, PowerPlex® ESI 17, Investigator® ESSplex SE Kit and P11, a non-commercial kit. We employed the results of double or triple analyses for a comparison of different types of interpretation rules based on reporting either only reproducible alleles (consensus interpretation) or all alleles, even if they are only observed once (composite interpretation). The interpreted and composed profiles were compared to the known alleles of the contributors and a “degree of validity” was calculated. When only two single amplifications were taken into account, we observed a higher degree of validity for composite profiles. The difference for consensus interpretation could be compensated when a minimum of three amplifications were carried out. Using the same kit for repeat analyses increases the chances to yield reproducible results required for consensus interpretation. Combining different kits in a complementing approach, on the other hand, offers the opportunity to reduce the number of drop-out alleles: differences in amplicon lengths for specific markers between kits can increase the resulting information. In the case of a few amplifications available this effect might only be visible with the composite method. Several markers like SE33 are particularly affected by this. Based on our observations the consensus interpretation method may not reflect the original profile in an optimal way in some special cases like low template, degraded mixture stains. In those cases the composite interpretation could yield more complete results. However, such a composite profile should be used with caution and only for limited purposes. Generally recommending the consensus interpretation thus seems not to be justified: a more differentiated approach appears to be worthwhile, e.g. the amount of drop-outs, the number of replicates, choice and combination of kits and even a marker specific procedure might be taken into account. [Copyright &y& Elsevier]

Abstract: Theoretical cycle data and heat transfer of HFO-1234yf were calculated and compared with those of R134a. Drop-in tests for R134a and HFO-1234yf were carried out using refrigeration unit of a hermetic rotary compressor of 550 W nominal output power and plate heat exchangers. Results of the evaporator cooling effect and heat transfer, COP, and compressor efficiency at a defined condensation temperature and similar evaporation temperatures for the two refrigerants were calculated and compared. [Copyright &y& Elsevier]