Optimisation of a high-efficiency solar-driven organic Rankine cycle for applications in the built environment

Recent years have seen a strong increase in the uptake of solar technologies in the built environment. In combined heat and power (CHP) or cogeneration systems, the thermodynamic and economic ‘value’ of the electrical output is usually considered to be greater than that of (an equivalent) thermal output, and therefore the prioritisation of the electrical output in terms of system-level optimisation has been driving much of the research, innovation and technology development in this area. In this work, the potential of a solar CHP technology based on an organic Rankine cycle (ORC) engine is investigated. We present thermodynamic models developed for different collectors, including flat-plate collectors (FPC) and evacuated-tube collectors (ETC) coupled with a non-recuperative sub-critical ORC architecture to deliver power and hot water by using thermal energy rejected from the engine. Results from dynamic 3-D simulations of the solar collectors together with a thermal energy storage (TES) tank are presented. TES offers an important buffering capability during periods of intermittent solar radiation, as well as the potential for demand-side management (DSM). Results are presented of an optimisation analysis to identify the most suitable working fluids for the ORC unit, in which the configuration and operational constraints of the collector array are taken into account. The most suitable working fluids (R245fa and R1233zd) are then chosen for a whole-system optimisation performed in a southern European climate. The system configuration with an ETC array is found to be best-suited for electricity prioritisation, delivering an electrical output of 3,605 kWh/yr from a 60 m2 array. In addition, the system supplies 13,175 kWh/yr in the form of domestic hot water, which is equivalent to more than 6 times the average annual household demand. A brief cost analysis and comparison with photovoltaic (PV) systems are also performed

Computer-aided working-fluid design, thermodynamic optimisation and technoeconomic assessment of ORC systems for waste-heat recovery

The wider adoption of organic Rankine cycle (ORC) technology can be facilitated by improved thermodynamic performance and reduced costs. In this context the power system should be evaluated based on a thermeconomic assessment with the aim of improving economic viability. This paper couples the computer- aided molecular design (CAMD) of the working-fluid with thermodynamic modelling and optimisation, in addition to heat-exchanger sizing models, component cost correlations, and a thermoeconomic assessment. The proposed CAMD-ORC framework, based on the SAFT-γ Mie equation of state, allows the thermodynamic optimisation of the cycle and working-fluid in a single stage, thus removing subjective and pre-emptive screening criteria that would otherwise exist in conventional studies. Following validation, the framework is used to identify optimal working-fluids for three different heat sources (150, 250 and 350 °C), corresponding to small- to medium-scale applications. In each case, the optimal combination of working-fluid and ORC system is identified, and investment costs are evaluated. It is observed that fluids with low specific-investment costs (SIC) are different to those that maximise power output. The fluids with the lowest SIC are isoheptane, 2-pentene and 2-heptene, with SICs of 5,620, 2,760 and 2,070 £/kW respectively, and corresponding power outputs of 32.9, 136.6 and 213.9 kW

Chemical analysis and antimicrobial activities of the essential oils of Satureja thymbra L. and Thymbra spicata L. and their main components

This work covers the chemical composition and antimicrobial activities of the essential oils isolated from Satureja thymbra and Thymbra spicata analyzed using GC/MS. The main components of S. thymbra oil were thymol (33.8 %), γ-terpinene (30.8 %) and p-cymene (11.8 %). The main components in T. spicata oil were carvacrol (74.5 %) and γ-terpinene (11.2 %). The oils and their main components, thymol and carvacrol, were assayed by applying the microdilution method for antibacterial and antifungal activity against food poisoning, plant, animal and human pathogenic microorganisms. The oil of T. spicata and carvacrol showed the highest antimicrobial activity.Projekat ministarstva br. 17303

First steps towards pre-breeding of Sideritis scardica: a phenotypic, agronomic, and phytochemical profiling approach

Sideritis scardica (S. scardica) Griseb., also known as mountain tea, is an important medicinal and aromatic plant species. Due to the high cross-pollination ability of the species, diverse genotypes and phenotypes occur naturally. Considering that superior uniform genotypes are necessary for highly qualitative and sustainable production, this study aimed to conduct a pre-breeding evaluation of three clones (SID1, SID2, and SID3) originating from a selected S. scardica population growing in Greece. According to a phenotypic and agronomic evaluation, SID2 seemed to be superior among the three clones, expressing a good profile with desirable traits (i.e., desired inflorescence length and leaf surface, high length of stems, and high fresh and dry plant biomass). Furthermore, SID3 presented some remarkable measurements regarding morphological (upright growth habit) and agronomic (high number of stems and plant dry weight, desired plant surface) traits. The phytochemical profile of the three clones was assessed with regard to their volatile and polyphenolic compounds. Forty-four constituents were identified in S. scardica essential oil, including hydrocarbon monoterpenes, sesquiterpenoids, oxygenated monoterpenes, and other groups (monoterpene ketones, saturated fatty alcohols, benzoic esters). Liquid chromatographic analysis revealed SID2 as the clone most abundant in the major polyphenolic metabolites: verbascoside (2234.3 mg 100 g−1), isoscutellarein-7-O [6′′-O-acetyl]-allosyl(1 → 2) glucoside (1456.5 mg 100 g−1), and 4-methyl hypolaetin-7-O [6′′-O-acetyl]-allosyl(1 → 2) glucoside (861.8 mg 100 g−1). The results indicate the ability to combine morphological, agronomic, and phytochemical traits, in order to identify superior S. scardica genotypes for further evaluation and utilization in breeding programs, aiming to create cultivars or varieties for farming purposes with desired performance and high quantitative and qualitative yield

Consumers' willingness to pay for an animal welfare food label

Consumers increasingly rate the ethical dimensions of food production, including animal welfare, as important to them but how these concerns influence their food choices remains unclear. To address this, a Discrete Choice Experiment assesses consumers' willingness to pay for chicken meat. The study aims to understand the effects of food labels (RSPCA Assured and Red Tractor), cause-related marketing campaigns, and price on consumers' willingness to pay. Drawing on a representative sample of 401 British consumers, we estimate a mixed logit model using the hierarchical Bayesian estimation method. The results for the full sample reveal a substantial price premium associated with the animal welfare label (RSPCA Assured); however, this is less pronounced than one of the cause-related marketing campaigns. A latent class analysis identifies two distinct market segments, price sensitive and concerned consumers, which differ on socio-economic and behavioural characteristics. Amongst price sensitive consumers, willingness to pay extra for an animal welfare label is negligible. Complementary, qualitative interviews reveal consumers' difficulties in comparing the varying standards that underpin quality assurance schemes

The Dimroth rearrangement as a probable cause for structural misassignments in imidazo[1,2-a]pyrimidines: A 15N-labelling study and an easy method for the determination of regiochemistry

Structural misassignments are often seen for complex natural products, but this can also be an issue with seemingly simpler structures. In this paper, we describe how, using a15N-labelled analogue, we established that the Dimroth rearrangement can occur in imidazo[1,2-a]pyrimidines and result in an incorrect regiochemical assignment of such compounds. These studies supported a rearrangement mechanism involving addition of hydroxide ion followed by ring opening. It was also observed that C(2) and C(3) substituted regioisomers could be readily distinguished using1H NMR spectroscopy

Oral Condition and Incident Coronary Heart Disease: A Clustering Analysis

Poor oral health has been linked to coronary heart disease (CHD). Clustering clinical oral conditions routinely recorded in adults may identify their CHD risk profile. Participants from the Paris Prospective Study 3 received, between 2008 and 2012, a baseline routine full-mouth clinical examination and an extensive physical examination and were thereafter followed up every 2 y until September 2020. Three axes defined oral health conditions: 1) healthy, missing, filled, and decayed teeth; 2) masticatory capacity denoted by functional masticatory units; and 3) gingival inflammation and dental plaque. Hierarchical cluster analysis was performed with multivariate Cox proportional hazards regression models and adjusted for age, sex, smoking, body mass index, education, deprivation (EPICES score; Evaluation of Deprivation and Inequalities in Health Examination Centres), hypertension, type 2 diabetes, LDL and HDL serum cholesterol (low- and high-density lipoprotein), triglycerides, lipid-lowering medications, NT-proBNP and IL-6 serum level. A sample of 5,294 participants (age, 50 to 75 y; 37.10% women) were included in the study. Cluster analysis identified 3,688 (69.66%) participants with optimal oral health and preserved masticatory capacity (cluster 1), 1,356 (25.61%) with moderate oral health and moderately impaired masticatory capacity (cluster 2), and 250 (4.72%) with poor oral health and severely impaired masticatory capacity (cluster 3). After a median follow-up of 8.32 y (interquartile range, 8.00 to 10.05), 128 nonfatal incident CHD events occurred. As compared with cluster 1, the risk of CHD progressively increased from cluster 2 (hazard ratio, 1.45; 95% CI, 0.98 to 2.15) to cluster 3 (hazard ratio, 2.47; 95% CI, 1.34 to 4.57; P < 0.05 for trend). To conclude, middle-aged individuals with poor oral health and severely impaired masticatory capacity have more than twice the risk of incident CHD than those with optimal oral health and preserved masticatory capacity (ClinicalTrials.gov NCT00741728)

Chemical analysis and antimicrobial activities of the essential oils of Satureja thymbra L. and Thymbra spicata L. and their main components

This work covers the chemical composition and antimicrobial activities of the essential oils isolated from Satureja thymbra and Thymbra spicata analyzed using GC/MS. The main components of S. thymbra oil were thymol (33.8 %), γ-terpinene (30.8 %) and p-cymene (11.8 %). The main components in T. spicata oil were carvacrol (74.5 %) and γ-terpinene (11.2 %). The oils and their main components, thymol and carvacrol, were assayed by applying the microdilution method for antibacterial and antifungal activity against food poisoning, plant, animal and human pathogenic microorganisms. The oil of T. spicata and carvacrol showed the highest antimicrobial activity.Projekat ministarstva br. 17303

Towards elucidating carnosic acid biosynthesis in Lamiaceae: Functional characterization of the three first steps of the pathway in Salvia fruticosa and Rosmarinus officinalis

Carnosic acid (CA) is a phenolic diterpene with anti-tumour, anti-diabetic, antibacterial and neuroprotective properties that is produced by a number of species from several genera of the Lamiaceae family, including Salvia fruticosa (Cretan sage) and Rosmarinus officinalis (Rosemary). To elucidate CA biosynthesis, glandular trichome transcriptome data of S. fruticosa were mined for terpene synthase genes. Two putative diterpene synthase genes, namely SfCPSand SfKSL, showing similarities to copalyl diphosphate synthase and kaurene synthase-like genes, respectively, were isolated and functionally characterized. Recombinant expression in Escherichia coli followed by in vitro enzyme activity assays confirmed that SfCPS is a copalyl diphosphate synthase. Coupling of SfCPS with SfKSL, both in vitro and in yeast, resulted in the synthesis miltiradiene, as confirmed by 1D and 2D NMR analyses (1H, 13C, DEPT, COSY H-H, HMQC and HMBC). Coupled transient in vivo assays of SfCPS and SfKSL in Nicotiana benthamiana further confirmed production of miltiradiene in planta. To elucidate the subsequent biosynthetic step, RNA-Seq data of S. fruticosa and R. officinalis were searched for cytochrome P450 (CYP) encoding genes potentially involved in the synthesis of the first phenolic compound in the CA pathway, ferruginol. Three candidate genes were selected, SfFS, RoFS1 and RoFS2. Using yeast and N. benthamiana expression systems, all three where confirmed to be coding for ferruginol synthases, thus revealing the enzymatic activities responsible for the first three steps leading to CA in two Lamiaceae genera

Integrated genomics and proteomics define huntingtin CAG length-dependent networks in mice.

To gain insight into how mutant huntingtin (mHtt) CAG repeat length modifies Huntington's disease (HD) pathogenesis, we profiled mRNA in over 600 brain and peripheral tissue samples from HD knock-in mice with increasing CAG repeat lengths. We found repeat length-dependent transcriptional signatures to be prominent in the striatum, less so in cortex, and minimal in the liver. Coexpression network analyses revealed 13 striatal and 5 cortical modules that correlated highly with CAG length and age, and that were preserved in HD models and sometimes in patients. Top striatal modules implicated mHtt CAG length and age in graded impairment in the expression of identity genes for striatal medium spiny neurons and in dysregulation of cyclic AMP signaling, cell death and protocadherin genes. We used proteomics to confirm 790 genes and 5 striatal modules with CAG length-dependent dysregulation at the protein level, and validated 22 striatal module genes as modifiers of mHtt toxicities in vivo