Energy impact evaluation of different low-GWP alternatives to replace R134a in a beverage cooler. Experimental analysis and optimization for the pure refrigerants R152a, R1234yf, R290, R1270, R600a and R744

Due to the entry into force in 2014 of the European F-Gas Regulation n° 517/2014 and the subsequent Kigali amendment, the phase-out of the medium and high-GWP refrigerants has speeded up in all refrigeration fields. The effect on the plug-in or stand-alone systems has meant that other environmentally friendly refrigerants must replace the R134a with low or ultra-low GWP maintaining the same operating conditions and reducing the energy consumption. Extended examples of these fluids are the hydrocarbons R600a and R290 and the inorganic fluid R744 (CO2). However, there are other alternatives to the HFCs R152a and R1234yf or the hydrocarbon R1270 that have hardly been analysed and can make a positive contribution to this sector. Accordingly, this work aims to evaluate the behaviour of a commercial beverage cooler experimentally when it is optimised with six alternatives to the HFC R134a: R152a, R1234yf, R290, R1270, R600a and R744. Results demonstrated that fluids R290, R1270, R152a, R744 and R600a reduce the energy of R134a in 27.5%, 26.3%, 13.7%, 3.9% and 1.2%, respectively, while the use of R1234yf increases the energy usage to 4.1%.Funding for open access charge: CRUE-Universitat Jaume

Energy impact of the Internal Heat Exchanger in a horizontal freezing cabinet. Experimental evaluation with the R404A low-GWP alternatives R454C, R455A, R468A, R290 and R1270

This work analyses the influence of the Internal Heat Exchan ger (IHX) on the energy performance of a vapor compression cycle associated with a freezing cabinet using different R404A low-GWP alternatives. Among them, the refrigerants R454C (GPW100=146), R455A (GPW100=146), R468A (GPW100=146), R290 (GPW100=5) and R1270 (GPW100=1.8) have been tested in a horizontal freezing cabinet maintaining a product target temperature of -20°C at the heat rejection temperatures of 20, 30 and 40°C. The results from tests show that the use of the IHX reduces energy consumption in all scenarios without significantly increasing the compressor's discharge temperature. For a test period of 16 hours, the refrigerants that offer better reductions are R404A and R1270, followed by R455A, R290, R454C and R468A. The maximum energy saving is rated to 9.2% at the heat rejection temperature of 40°C, demonstrating that the enhancement of the IHX is better as higher the heat rejection conditions are.Funding for open access charge: CRUE-Universitat Jaume

Visualització 3D i docència en ciències experimentals: Aplicació sobre els ensenyaments de la Facultat de Geologia de la UB

Aquest projecte va ser plantejat considerant útils per al treball docent i la seva millora les noves eines de visualització tridimensional (tant en 2D, en pantalla convencional, com en 3D en monitors adaptats per la visualització amb ulleres estereoscòpiques). La Facultat de Geologia de la UB acumulava a l’inici del projecte (2012), i ha seguit incrementant en aquests dos darrers anys (2013-2015), un important potencial en visualització tridimensional, que es pot transferir a la docència. Es volia contrastar la capacitat tècnica en aquest camp de diversos grups de recerca i departaments de la Facultat de Geologia. També analitzar com obrir noves formes en els ensenyaments de grau (Geologia, Enginyeria Geològica) i postgrau (Geologia i Geofísica de Reservoris, Oceanografia i Gestió del Medi Marí). La naturalesa del projecte va dur a plantejar dues etapes: 1) 2013: Inventari i coordinació de recursos medis i coneixement disponibles des dels diversos grups de recerca i docents per poder-los aplicar a la millora i al disseny de noves eines docents. Inici del disseny, concepció, preparació i desenvolupament de les primeres pràctiques a desenvolupar. Primeres aplicacions experimentals de les pràctiques en les assignatures de graus i màsters. 2) 2014: Finalització del disseny de noves pràctiques i contrastació de les avantatges (millora de les exposicions de conceptes i dades, grau d’assimilació dels estudiants) i dificultats plantejades (tècniques, de falta de mitjans materials i humans). Anàlisi de quines solucions tècniques foren les millors per l’ ús el més generalitzat possible dels materials docents desenvolupables. Establiment de conclusions particulars i generals. Dins de l’àmbit del projecte s’ha concretat que un disseny adient per a una aula d'informàtica i/o una sala laboratori a on aplicar la metodologia de la visualització 3D a la docència pràctica seria una sala amb no més de 15 a 25 ordinadors, de mobiliari modular de posició modificable, però tenint present la necessitat d’una connexió en xarxa; amb pantalla-es frontal i/o lateral visibles per als estudiants i situades a una alçada per sobre dels monitors; i un ordinador de professor en el que mostrar als estudiants els procediments i la marxa de les pràctiques. La diversitat de programari disponible pels diferents grups, a partir del qual es poden generar documents tractables com a material 3D pot implicar un problema ja que aquesta diversitat implica una certa dispersió d’esforços per part del professorat i dificultat d’aprenentatge per als estudiants. Com a resultat de l’experiència es suggereix que el material docent amb possibilitats de rebre tractament 3D en visió normal o estereoscòpica podria ser transferit des dels formats originals en el que són generats a un altre únic estàndard, que facilités el seu ús sense haver de conèixer en profunditat el software d’origen ni que calgués tenir-lo instal·lat. L’experiència d’aquests dos anys suggereix que perquè el professorat pugui fer una explotació intensiva dels recursos disponibles s’ha de comptar amb: 1) Una disciplina de programació amb prou anticipació de les activitats. 2) Un mínim de personal de suport que tingui capacitat de mantenir el programari i el maquinari a punt La utilització de dades derivades de models geològics experimentals analògics per preparar bases de dades digitals amb les que construir models 3D és una novetat docent dins de l’àmbit estatal i poc freqüent a universitats europees i de la resta del món

The influence of a badminton competition with two matches in a day on muscle damage and physical performance in elite junior badminton players

[EN] To investigate the effects of a badminton competition with 2 matches in a day on hip strength and range of motion (ROM) and exercise-induced muscle damage in elite junior badminton players. Twenty players (age: 17±0.8 years; body mass: 62.9±6.5 kg, height: 173.8±8.9 cm) participated in this study. Passive hip internal (IR) and external rotation (ER), abduction (ABD) and adduction (ADD) hip ROM, isometric hip ADD and ABD muscle strength, countermovement vertical jump (CMJ) height and blood creatine kinase concentration (CK) were measured before and after a badminton competition during an international tournament. Blood samples were collected 24 h after the end of the last match. Compared to baseline values, hip IR and ER ROM were significantly decreased at post-competition in the dominant (IR=-9.0%; p=0.007 and ER=-15.2%; p=0.002) and non-dominant limbs (IR=-9.08%; p=0.004 and ER=-19.4%; p<0.001). In contrast, hip ADD (13.5%; p<0.001) and ABD (14.6%; p<0.001) strength increased significantly after the competition in the dominant limb and ABD strength increased significantly in the non-dominant limb (9.2%; p=0.001). From baseline values, CK increased after the competition (430.1%) and values remained elevated over baseline values 24 h later (160.4%). Although hip muscle strength increased, a badminton competition with two consecutive matches reduced hip ROM and increased blood CK concentration. This study suggests the necessity of investigating recovery strategies after a badminton competition to return hip ROM to basal values before the next day of the competition.SIThe authors would like to express their gratitude to badminton play- ers who participated in the study.Funding received from Badminton World Federation (BWF), Kuala Lumpur (Malaysia

Reduced glutathione and Trolox (vitamin E) as extender supplements in cryopreservation of red deer epididymal spermatozoa

P. 37-46The use of assisted reproductive techniques in cervids is increasing as the commercial use of these species increase. We have tested the suitability of the antioxidants Trolox and reduced glutathione (GSH) for freezing red deer epididymal spermatozoa, aiming at improving post-thawing quality. Samples from 19 stags were frozen in a TES-Tris-fructose extender (20% egg yolk, 8% glycerol), with 1 or 5 mM of antioxidant. Motility (CASA), lipoperoxidation (malondialdehyde –MDA– production), membrane status, mitochondrial activity, acrosomal status (flow cytometry) and chromatin status (SCSA: %DFI and %HDS; flow cytometry) were assessed after thawing and after 6 h at 39 °C. There were few differences between treatments after thawing, with Trolox reducing MDA production in a dose–response manner. After the incubation, sperm quality decreased and %DFI increased moderately, with no change for MDA. GSH improved motility, kinematic parameters and mitochondrial status, with a slight increase in %HDS. GSH 5 mM also increased moderately MDA production and %DFI, possibly due to enhanced metabolic activity and reducing power. Trolox maintained MDA low, but was detrimental to sperm quality. Trolox might not be appropriate for the cryopreservation of red deer epididymal spermatozoa, at least at the millimolar range. GSH results are promising, especially regarding motility improvement after the post-thawing incubation, and should be selected for future fertility trials.S

Cryopreservation of Iberian red deer (Cervus elaphus hispanicus) spermatozoa obtained by electroejaculation

P. 628-638We tested extenders and freezing protocols for Iberian red deer semen. Samples were obtained by electroejaculation (10 stags), and analyzed for motility (CASA), viability (propidium ioide), acrosomal (PNA-FITC) and mitochondrial status (JC-1). Samples were diluted in extender, cooled and adjusted for glycerol (extender with higher glycerol concentration), brought to mL−1 and frozen. Four experiments were carried out, repeating sperm analysis after thawing to compare treatments. In a first experiment, seven samples were frozen using Triladyl® (20% egg yolk) and UL extender (Tes–Tris–fructose, 15% egg yolk, 4% glycerol). Triladyl® yielded higher motility after thawing. In a second trial, 17 samples were frozen using Triladyl®, Andromed®, Bioxcell®, and UL with 8% LDL (low-density lipoproteins). Triladyl® and Andromed® performed better than Bioxcell® on motility, and than UL-LDL on viability and acrosomal status. In a third experiment, the performance of freezing the sperm-rich ejaculate fraction versus the whole ejaculate was tested on nine samples. The sperm-rich ejaculate fraction not only rendered more motile and viable spermatozoa but also showed higher freezability (higher motile spermatozoa recovery). In a fourth experiment, we tried three modifications of the freezing protocol, for improving the freezability of low concentration samples: prior removal of seminal plasma; replacing extender (second fraction) for pure glycerol to reduce dilution; and performing only the dilution, not the second dilution. No differences were found, although only three samples could be used. Both Triladyl® and Andromed® were deemed appropriate for freezing Iberian red deer semen, and the rich fraction should be selected for freezing.S

Impacts of the volcanic eruption in La Palma (Canary Islands) on the nearby marine bacterioplankton communities

Trabajo presentado en ASLO Aquatic Sciences Meeting 2023, celebrado en Palma de Mallorca (España), entre el 4 y el 9 de mayo de 2023.The volcanic eruption that occurred in La Palma Island (Canary Islands, Spain) in 2021 resulted in molten lava flowing into the ocean and forming a delta in the coastline, besides the emission of large amounts of ashes being deposited in a vast area around the Canary Islands. In order to assess the effects of the eruption on seawater, two oceanographic cruises were carried out, one at the beginning of the eruption and a second one a month later. We used an oceanographic CTD rosette sampler for collecting seawater in different areas of La Palma coastline together with Unmanned Aerial Vehicles (UAVs) equipped with a sampling device to collect surface samples near the delta newly formed on the coastal fringe. We sequenced the 16S rRNA gene in order to assess the response of bacterioplankton to such natural disturbance. The results show that the abundance of Thiomicrospirales, Gammaproteobacteria capable of oxidizing poly-metal sulfides, increased significantly in UAV samples collected near the lava delta. Moreover, in stations where the largest physical-chemical anomalies were recorded with the CTD, sequence data showed drastic changes in the prokaryotic community structure; cyanobacterial abundance decreased while the ammonia-oxidizing archeon Nitrosopelagicus and the bacterial SAR324 clade, with potential sulfur-based chemolithoautotrophic lifestyle, dominated the communities. The combined used of shipboard operations and UAVs provided a unique opportunity to study the prokaryotic response to a massive lava input, an event that is rarely observed and sampled in real time

Establishment of reference intervals for complete blood count in times of COVID-19 and vaccination

IntroductionCOVID-19 and vaccination may affect some parameters of the complete blood count (CBC). The aim of this study was to determine reference intervals (RI) of CBC in healthy population with different COVID-19 and vaccination backgrounds and compare them with those established previously. Materials and methodsA cross-sectional study was conducted in donors who attended the Traumatology Hospital “Dr. Victorio de la Fuente Narváez” (HTVFN) from June to September 2021. Reference intervals were established using the non-parametric method on Sysmex XN-1000. For differences between groups with different COVID-19 and vaccination backgrounds, non-parametric tests were used. ResultsThe RI were established in 156 men and 128 women. Haemoglobin (Hb), haematocrit (Hct), red blood cells (RBC), platelets (Plt), mean platelets volume (MPV), monocytes and relative neutrophils were higher in men than women (P < 0.001). The percentiles of Hb, Hct, RBC, MPV and relative monocytes showed higher values; Plt, white blood cells (WBC), lymphocytes, monocytes, neutrophils, eosinophils and absolute basophils, the 2.5th was higher and the 97.5th was lower; for lymphocytes and relative neutrophils, both percentiles had a trend toward lower values, compared to previous RI. Differences between groups with different COVID-19 and vaccination backgrounds, in lymphocytes (P = 0.038), neutrophils (P = 0.017) and eosinophils (P = 0.018) in men; Hct (P = 0.014), RDW (P = 0.023) in women and MPV (P = 0.001) in both, were not considered pathological. ConclusionsThe RI for the CBC were established in a Mestizo-Mexican population with different COVID-19 and vaccination backgrounds, so should be updated and validated in different hospitals close to the HTVFN that use the same analyser

Metabolismo óseo en niños y adolescentes deportistas: revisión sistemática

BACKGROUND: Physical exercise is beneficial for the prevention of osteoporosis. Bone metabolism markers are the main indicators of metabolic balance and may indicate early risk in bone tissue. AIM: This systematic review aims to summarize and update present knowledge about bone metabolism markers in child and adolescent athletes. METHOD: Literature search was conducted up to March 2017 in PubMed and Sport Discus. A total of 19 studies (case-control, longitudinal and randomized control trials) met the inclusion criteria and were included in the review. RESULTS: In females, bone remodeling decreases with age independently of sport practiced. Athletes with amenorrhea had lower levels of both markers of bone turnover than control subjects. High-impact sports present higher biomarkers in females. A brief period of training have positive effects in bone formation markers in adolescent males. CONCLUSIONS: The age, sex type of exercise and sport, and performance level of the subjects can deeply affect bone metabolism markers during adolescence. More studies are needed to establish common criteria for metabolic response to physical exercise in these stages

Modelling and experimental validation of a CO2 concentric tube evaporator using heat transfer correlations and flow pattern maps

Las regulaciones en materia de medio ambiente adoptan medidas cada vez más restrictas en aras de reducir la contaminación medioambiental, principalmente regulan dos aspectos en el mundo de la refrigeración, la carga máxima admisible de refrigerante en la instalación y el empleo de refrigerantes de bajo GWP. Por este motivo es importante disponer de una herramienta capaz de predecir el funcionamiento de los evaporadores de los sistemas de refrigeración dentro de las regulaciones estipuladas. En este artículo se presenta el modelo matemático generado para simular el funcionamiento de un evaporador de CO2 de tubos concéntricos y su validación experimental. La validación del modelo se realiza con el fin de generar una herramienta de cálculo capaz de optimizar el proceso de dimensionamiento de los evaporadores que se montan en los muebles frigoríficos en Frost-trol. Para realizar los cálculos de transferencia de calor se han introducido en el modelo correlaciones empíricas y correlaciones pseudoempíricas (patrones de flujo). Para la validación de los resultados del modelo se ha procedido al dimensionamiento y montaje de una instalación experimental. En este trabajo se realiza una comparación entre los resultados obtenidos para cada una de las diversas correlaciones y los datos medidos experimentales. El modelo final contendrá la correlación que más se ajuste a los datos experimentales