Obesity prevalence, nutritional status, and physical activity levels in Turkish adults during the COVID-19 pandemic.

Background: Although nutritional status is influenced by multidimensional aspects encompassing physical factors, there is limited research on this complex relationship. Objectives: This study aimed to examine the interaction between physical activity level indicators and the nutritional status of adults in Türkiye. Methods: A total of 3,970 individuals aged 18 years or older, residing in Afyonkarahisar (Türkiye), participated in this study. Data were obtained through face-to-face interviews with a questionnaire, using simple random sampling among adults. One-day food consumption was recorded using a 24-h dietary recall (24HDR). Physical activity levels were assessed using the International Physical Activity Questionnaire (IPAQ). Results: This study comprised 3,970 participants: 2,087 (52.57%) men and 1,883 (47.42%) women. Among them, 32.64% smoked cigarettes, and 8.72% consumed alcohol. About 40% of adults were overweight, and 16.33% were obese. All participants had inadequate intake levels of potassium, calcium, and iron when compared to the recommended amounts. Physical activity levels showed a weak positive correlation with dietary energy, carbohydrates, protein, fat, and cholesterol, and a weak negative correlation with age, waist-to-hip ratio, and BMI of participants. Conclusion: This study provides insights into the importance of addressing both physical activity and nutritional status. It was found that the weekly duration of physical activity for women was lower than for men. As a result of the nutritional status evaluation, it was found that the daily energy intake of men was higher than that of women.

Psychometric validation of an instrument to assess undergraduate nursing student's knowledge of the aetiology, prevention and treatment of venous leg ulcers.

BACKGROUND: In the management of individuals with venous leg ulcers, education serves as a pivotal tool for acquiring knowledge, fostering appropriate attitudes, and promoting best practices. Consequently, assessing knowledge, skills, attitudes, confidence, and commitment becomes essential, necessitating the development of suitable evaluation instruments. Pre- and post-test assessments align with Level 2 of Kirkpatrick's model. Moreover, nurse educators should integrate assessment into the teaching-learning sequences. AIM: To psychometrically validate an instrument designed to assess undergraduate nursing students' knowledge of the aetiology, prevention, and treatment of venous leg ulcers. DESIGN: A multi-phase study was designed to develop the tool and subsequently validate its psychometric properties. SETTING(S): The study was conducted at three sites within the University of the Basque Country and one site within the University of Alicante. PARTICIPANTS: A total of 516 students from all four years of the nursing degree program participated. METHODS: The construct definition and instrument development were previously published. This article presents the psychometric evaluation, which involved classical item analysis, analysis of psychometric properties according to the Rasch model, differential item functioning analysis, construct validity analysis through hypothesis testing in known groups, and reliability analysis via internal consistency. RESULTS: The results validated the Knowledge on Venous Leg Ulcer Questionnaire, reducing it from 72 initial items to 36 definitive items. It was found to be a valid and reliable instrument, capable of detecting statistically significant differences between known groups. Knowledge scores on a 0-100 scale were found to be 33.1 (SD = 19.5) for the first-second year groups, and 48.3 (SD = 17.5) for the third-fourth year groups, demonstrating a progressive and logical increase in knowledge each year. CONCLUSIONS: The Knowledge on Venous Leg Ulcer Questionnaire appears to be a valid and reliable instrument for measuring nursing students' knowledge of venous leg ulcers. However, further research in different contexts is required to confirm these results.

CastelLact Project: Exploring the Nutritional Status and Dietary Patterns of Pregnant and Lactating Women-A Comprehensive Evaluation of Dietary Adequacy.

Promoting optimal nutrition in pregnant and lactating women is crucial for maternal and infant health. This study evaluated their nutritional status and dietary habits, assessing macro and micronutrient intake based on recommendations. A descriptive study with Spanish participants examined social, obstetric, dietary, and anthropometric data using quantitative and qualitative methods. The analysis of fatty acids by gas chromatography revealed significant variability, with notable deviations in specific fatty acids like C:10:0 and C:12:0. Despite some differences, the overall composition aligns with standards. During pregnancy, 53.8% consumed five meals/day. Grilling (92.3%) and baking (76.9%) were common. Food consumption frequency differed from recommendations. Lactating mothers' mean energy intake was 2575.88 kcal/day ± 730.59 standard deviation (SD), with 45% from carbohydrates and 40% from lipids, including 37.16 g ± 10.43 of saturated fatty acids. Diets during pregnancy lacked fruits, vegetables, legumes, nuts, and cereals. Lactating mothers partially met nutritional objectives, with an energy distribution skewed towards lipids and deficiencies in calcium, iodine, vitamin D, E, and folic acid. Promoting proper nutrition during pregnancy and lactation is essential to safeguard health and prevent chronic diseases.

Food-Intolerance Genetic Testing: A Useful Tool for the Dietary Management of Chronic Gastrointestinal Disorders.

The rise in food intolerances and celiac disease, along with advanced diagnostic techniques, has prompted health professionals to seek effective and economical testing methods. This study evaluates combining genetic tests with routine carbohydrate-absorption breath tests to classify patients with chronic gastrointestinal disorders into therapeutic groups, enhancing dietary management and improving gut health and quality of life. Forty-nine patients with suspected carbohydrate intolerance underwent genetic testing for lactase non-persistence, hereditary fructose intolerance, and celiac disease risk. Simultaneously, breath tests assessed lactose and fructose absorption. The lactase non-persistence genotype appeared in 36.7% of cases, with one hereditary fructose-intolerance case in a heterozygous condition. Celiac disease risk markers (HLA-DQ2/8 haplotypes) were found in 49.0% of the population. Secondary lactose and/or fructose malabsorption was present in 67.3% of patients, with 66.1% of lactase non-persistence individuals showing secondary lactose malabsorption. Fructose malabsorption was prevalent in 45.8% of patients at risk for celiac disease. Two main treatment groups were defined based on genetic results, indicating primary and irreversible gastrointestinal disorder causes, followed by a sub-classification using breath test results. Genetic testing is a valuable tool for designing dietary management plans, avoiding unnecessary diet restrictions, and reducing recovery times.

Randomized Controlled Trial of Interventions Used by Midwives to Treat Fear of Childbirth.

BACKGROUND: Fear of childbirth affects women worldwide and can have adverse consequences. Midwives have implemented a number of interventions, autonomously or as part of a professional team. However, midwives have been unable to identify the most appropriate intervention for ensuring the reduction or alleviation of this fear to provide the best perinatal outcomes. OBJECTIVE: This study aimed to evaluate the effectiveness of a prenatal educational intervention followed by specific support during childbirth, designed and delivered exclusively by midwives for women with a high fear of childbirth. METHOD: This randomized controlled trial was performed with two arms in two phases: an online prenatal education phase followed by a support phase during childbirth. Participating women with a high fear of childbirth, which was determined using the Wijma Delivery Expectancy Questionnaire-A-Spanish version, were assigned to the experimental group or the usual care control group at a 1:1 ratio. RESULTS: Women showed a reduction in fear of childbirth in both phases of the study. According to the intention to treat analysis, a significant mean difference was observed in the prenatal stage in favor of the intervention group, as well as a nonsignificant difference in favor of this same group after delivery. DISCUSSION: The effectiveness of continuous specific prenatal education with preferential support during childbirth by midwives was indicated by improvements in the level of fear of childbirth.

Construct validity and reliability of the BARRIERS scale in the Spanish context.

OBJECTIVE: To establish the construct validity of the Spanish version of the BARRIERS scale. METHOD: Methodological study of validation of a measurement instrument based on data from previously published studies. The study population consisted of nurses from the Basque Health Service and the Canary Health Service. The following variables were extracted and unified: Years of professional experience, possession of a specialist nursing degree, possession of a doctorate, type of activity performed by the professional and field of work. For construct validation, a confirmatory factor analysis (CFA) was performed based on the initial model proposed for the scale and RASCH analysis. A polychoric correlation matrix, factor extraction by unweighted least squares and PROMIN oblique rotation were used. For the RASCH analysis, the Joint Maximun Likelihood estimation (JMLE) method was used; the fit of the items and persons were estimated by means of outfit - Unweighted Mean Square fit statistic (UMS) and infit -Weighted Mean Square Fit Statistic (WMS), as well as the reliability and separation of items and persons. RESULTS: A total of 1200 nurses and midwives made up the final validation sample (n = 1200), with a mean professional experience of 21.22 ± 9.26 years. The CFA presented a good fit to the data (KMO = 0.935 [95% CI: 0.921-0.945]), changing the factorial assignment in 6 items, while 5 items received factorial scores in more than one factor. The fit values for the 4-factor solution were RMSEA = 0.026 [95% CI: 0.026-0.027] and GFI = 0.991 [95% CI: 0.986-0.991]. In the RASCH analysis most items presented infit-WMS and outfit-UMS values with a good fit. CONCLUSIONS: The Spanish version of the BARRIERS scale has adequate construct validity although there are changes in the assignment of items to the dimensions compared to the original model. The RASCH analysis indicates adequate fit for both persons and items.

Overvaluation of weight and shape in obesity: a comparative study between people with and without binge eating disorder.

Introduction: The overvaluation of weight and shape is a diagnostic criterion in eating disorders, except in binge eating disorder (BED), where it has received less attention. This aspect is also not usually analyzed in people with overweight or obesity without an eating disorder. This research aims to identify the indicators of symptomatology, as well as those of self-construction and cognitive structure, that are associated with overvaluation in obesity, either alone or in conjunction with BED. Method: A sample of 102 overweight or obese participants was accessed. The sample was divided into four groups: one without overvaluation or BED (n = 33); a second with overvaluation and without BED (n = 21); a third with BED, but without overvaluation (n = 15), and a fourth with BED and overvaluation (n = 33). The groups completed instruments regarding eating symptomatology, anxiety, depression, and stress. In addition, they were administered the Repertory Grid Technique, a semi-structured interview to evaluate the cognitive structure involved in the construal of the self and others. Results: The factors of overvaluation and the presence of BED independently explained eating symptomatology, and the latter also showed a tendency to influence anxiety, depression, and stress. In terms of cognitive structure, weight polarization was explained by overvaluation, while BED was associated with a high presence of cognitive conflicts. In self-construction, BED was the factor that explained the differences, particularly in Self-Ideal discrepancy. Discussion: The results highlight the importance of overvaluation in obesity, even in the absence of BED. Its evaluation and treatment are recommended. Furthermore, in the case of BED, it is also advisable to evaluate the overvaluation of weight and shape since it can be a severity specifier.

Effectiveness of "Escape Room" Educational Technology in Nurses' Education: A Systematic Review.

Escape room games are educational gamification technologies that consist of introducing a team of players into a physical or digital space in search of clues to answer puzzles, riddles or enigmas and solve a mystery or problem. This study aims to determine the effectiveness of escape room games on the training of nursing students in an international context. A systematic review was carried out in MEDLINE, WOS, SCOPUS, CINAHL and LILACS databases using the MeSH terms "Education, Nursing" and "Educational Technology", and the free term "Escape room", combined with Boolean operators AND/OR. Intervention studies in Spanish, English and Portuguese were included, without limitation for the year of publication. Selection and critical appraisal were conducted by two independent reviewers. A total of n = 13 interventional studies were included (n = 2 Randomized Clinical Trials and n = 11 quasi-experimental design). Escape rooms are a recent and growing educational methodology, increasingly used in academia and in the training of nurses and nursing students. However, it is necessary to expand their use and the quality of the studies in a greater number of contexts. Furthermore, it is necessary to homogenize and standardize validated instruments to evaluate the effectiveness of escape rooms in the nursing education area.

Evaluation of nutritional status using the minimum dietary diversity for women of reproductive age (MDD-W) tool in breastfeeding mothers in Madagascar.

OBJECTIVES: Women of reproductive age in low-income countries are especially nutritionally vulnerable given the strain that pregnancy and lactation places on the body. The aim of this study was to identify dietary diversity and its associated factors among mothers with young children. METHODS: It is a cross-sectional study conducted in Ampefy, Madagascar from 1 November 2022 to 31 March 2023. Dietary diversity was determined using the minimum dietary diversity for women of reproductive age tool. Data were collected through face-to-face interviews using validated structured questionnaires, and anthropometric status was examined. Frequencies and percentages were calculated, and the comparison of variables was performed between mothers with acceptable and unacceptable dietary diversity using the chi-square test for qualitative variables. A logistic regression analysis was also conducted. RESULTS: A total of 437 mothers with young children participated in the study, resulting in a response rate of 95.0%. The mean age of the participants was 25.84 years (SD = 6.30). The study revealed that 32.95% of participants had unacceptable dietary diversity scores and the associated profile included low education, no transport, homebirth not by personal choice, not breastfeeding within the first hour of birth, not breastfeed exclusively for 6 months, no dietary changes during pregnancy or lactation, and no use of folic acid supplements. CONCLUSION: This study's findings underscore the importance of providing nutrition information to women, in order to improve dietary diversity and overall maternal and child health.

Long-lasting symptoms in borderline personality disorder: Defining an emergent population with differential clinical and therapeutic features.

Although the clinical symptoms of borderline personality disorder (BPD) tend to remit over time, a substantial proportion continues to present "long-lasting symptoms" (LLS). This term refers to individuals who present some degree of clinical improvement, but low mood, feelings of emptiness, and poor psychosocial adjustment typically persist. The aim of this study was to compare the sociodemographic, clinical, and therapeutic variables in individuals with BPD with and without LLS. A total of 620 participants with BPD were included and subdivided into two groups: non-LLS group (n = 549, mean age = 28.02 [6.1] and range, 18-40 years) and LLS group (n = 71, mean age = 44.69 [3.6] and range, 41-56 years). The groups were compared in sociodemographic, clinical, and drug treatment characteristics. We also evaluated the impact of dialectical behavioral therapy-skills training (DBT-ST) on polypharmacy. The prevalence of individuals with long-lasting BPD symptoms increased significantly over a 20-year period (from <1% to 16%). The LLS group was characterized by less clinical severity, higher comorbidity with affective disorders but lower comorbidity with eating disorders, more disability, and more medication taking. Patients with LLS who received DBT-ST experienced a significant decrease in the use of benzodiazepines and the number of medications prescribed compared with those who did not receive DBT-ST. Clinicians should be aware of the specific features of older patients with BPD in order to better identify and address their specific therapeutic needs.

Analysis of Fluid Balance and Urine Values in Elite Soccer Players: Impact of Different Environments, Playing Positions, Sexes, and Competitive Levels.

Exercise can disrupt the fluid balance, hindering performance and athlete health. Limited data exist on fluid balance responses in varying climates, sexes, and ages. This study aimed to measure and compare fluid balance and urine values among elite soccer players during training at high and low temperatures, examining the differences between sexes, playing positions, and competitive levels within men's soccer. During the 2022-2023 competitive season, a descriptive observational study was conducted on 87 soccer players from an elite Spanish soccer team. The study found that none of the groups exceeded weight loss values of 1.5% of their body mass. Additionally, the soccer players studied experienced higher weight loss, fluid intake, and a higher sweat rate (SR) during summer training compared to winter training. During the summer, male U23-21 soccer players exhibited higher levels of weight loss, fluid intake, and a higher SR compared to female soccer players or the U19-17 male category. No significant differences were found between playing positions. In conclusion, differences in the fluid balance were observed based on the climatic conditions, competitive level, and sex.

Supplement Consumption by Elite Soccer Players: Differences by Competitive Level, Playing Position, and Sex.

Soccer is a sport practiced all over the world and whose practice begins in young athletes. Currently, the consumption of nutritional supplements is essential to achieve the maximum performance of players. The aim of this study was to describe the consumption of sports supplements (CSS) by elite soccer players and its association with their competitive level, playing position, and sex. A comparative descriptive and non-experimental study was performed during the 2021-2022 competitive season. A total of 70 elite players completed one online questionnaire about their CSS. We found that sports drinks (55.7%), sports bars (50.0%), whey protein (48.6%), caffeine (47.1%), and creatine (60.0%) were the most consumed supplements by the total sample. Relative to the categories, the CSS was higher in the senior teams for both men and women. Regarding playing positions, caffeine was more consumed by midfielders and forwards (p = 0.013). Finally, in relation to sex, significant differences were found in the consumption of sports confectionery (p = 0.036), whey protein (p = 0.002), ß-alanine (p = 0.013), and melatonin (p = 0.016). Soccer club SS questionnaires gather data to understand patterns, assess effectiveness and risks, and aid research. In conclusion, differences were found in the CSS according to competitive level, sex, and playing position.

Assessment and Solutions to Food Waste at Congress Events: A Perspective of the MagNuS Project.

Addressing global food waste is a formidable challenge, requiring comprehensive efforts across the food supply chain, particularly in sectors prone to waste like HoReCa (Hotel, Restaurant, and Catering). In MICE (Meetings, Incentives, Conventions, and Exhibitions) tourism, where gastronomy is a major attraction, overlooked meal services during working meetings contribute significantly to food waste. The MagNuS (Magnitude, Nutritional value, and Sustainability) project aims to assess and address food waste during conference events at the Valencia Conference Center in Spain. This study quantifies waste, categorizes it by food groups, estimates the potential number of individuals that could be fed with discarded food, and assesses energy and nutritional values. Across three events, 104.4 kg of food waste was documented, with cereals having the highest wastage, followed by legumes, fish, and others. Acknowledging potential underestimation due to reliance on cooked values, this study suggests using residues for vermicomposting or composting as sustainable waste management alternatives. These findings have implications for future initiatives, advocating diverse strategies to minimize food waste during congress events, aligning with the Sustainable Development Goals. The MagNuS project contributes valuable insights to sustainable practices in MICE tourism, informing policies and operational decisions to reduce the environmental impact of food waste.

Termografía infrarroja como método de diagnóstico en quemaduras: una revisión exploratoria de la literatura / Infrared thermography as a method of diagnosis in burns: an exploratory review of the literature

Objetivos: Revisar el uso y eficacia de la termografía infrarroja como instrumento diagnóstico y de medida de las quemaduras. Metodología: Se realizan 2 búsquedas, una general y otra específica, utilizando estrategia de búsqueda mediante un lenguaje controlado con términos MESH. Para seleccionar los artículos se filtra por título, resumen y palabras clave, además de aplicarse los criterios de inclusión y exclusión. Resultados: Durante la búsqueda general, se encontraron 165 artículos en PubMed, de los cuales 7 han sido seleccionados y 6 han sido incluidos. Mientras que con la búsqueda específica se obtienen 28 artículos, de los cuales se seleccionan 7 que no aparecían en la búsqueda general y se incluyen finalmente 6 de ellos. Conclusiones: La termografía infrarroja es un instrumento con mucho potencial y que ha mostrado buenos resultados, pero en ocasiones mucha variabilidad e inconsistencia, por lo que es necesaria la estandarización de una serie de medidas que nos permitan contrarrestar las dificultades a las que se expone y minimizar los sesgos, hecho que podrá mejorar más los resultados. Además, es necesaria una mayor investigación aplicando las variables térmicas encontradas para identificar el grado de influencia e importancia que tienen y comparar las diferentes modalidades de termografía infrarroja, estática y dinámica.(AU)

Objectives: To review the use and efficacy of infrared thermography as a diagnostic instrument and measurement of burns. Methodology: Two searches were carried out, one general and the other specific, using a controlled language search strategy with MESH terms. To select the articles we filtered them by title, abstract and key words, besides applying the inclusion and exclusion criteria. Results: During the general search, 165 articles were found in PubMed, of which 7 were selected and 6 were included. The specific search yielded 28 articles, of which 7 were selected that did not appear in the general search and 6 were finally included. Conclusions: Infrared thermography is an instrument with great potential that has shown good results but much variability and inconsistency at times, so it is necessary to standardize a series of measures that allow us to counteract the difficulties to which it is exposed and minimize biases, a fact that could further improve the results. In addition, further research is needed by applying the thermal variables found to identify the degree of influence and importance that they have and by comparing the different infrared thermography modalities, static and dynamic.(AU)

Impact of weight loss after treatment on survival outcomes of overweight and obese patients with early­stage endometrial cancer.

Despite the fact that obesity is the main risk factor for endometrial cancer, there is limited evidence regarding the effects of body weight change on overweight and obese women treated for early-stage endometrial can its impact on cancer outcomes. A retrospective cohort study was performed including all overweight and obese patients with early-stage type-I endometrial cancer that were treated at the Insular University Hospital of Las Palmas (Las Palmas de Gran Canaria, Spain) between January 2007 and December 2019. Body weight change at 12 months of treatment was evaluated, as well as its impact on cancer outcomes. Weight loss ≥5% was independently evaluated regarding its impact on survival. A total of 526 women were studied, of which 152 (28.90%) were overweight (BMI ≥25 and <30) and 374 (71.10%) were obese (BMI ≥30). The median follow-up was 76.17 months, during which time 77 (14.64%) women died. In the survivor group, body weight at initial diagnosis was 86.4±17.9 kg compared with 84.6±16.4 kg 1 year after treatment, which corresponded to a significant mean weight loss of 1.47 kg (P<0.001). However, in the group of non-survivors, body weight at initial diagnosis was 84.7±15.7 kg compared with 84.7±14.6 kg 1 year after treatment, which demonstrated a non-significant mean weight loss of 0.63 kg (P=0.180). When comparing between the patients who maintained or gained ≥5% weight and those who lost ≥5% weight, there were no significant differences taking into account the whole cohort and follow-up time; however, when adjusting for the period between 32 and 98 months, survival was significantly higher in those patients that lost ≥5% of their initial body weight (P=0.025; log-rank test). Based on the final univariate and cer and multivariate analyses, body weight change at 12 months was not indicated to be a factor significantly affecting overall survival; adjusted hazard ratio was 1.01 (95% CI 0.97-1.05, P=0.723). In conclusion, even if greater weight loss is observed in patients with endometrial cancer that survive the disease, no significant impact on survival outcomes is observed based on multivariate analysis.

Sarcopenic Obesity in Community-Dwelling Spanish Adults Older than 65 Years.

Sarcopenic obesity (SO) is diagnosed when sarcopenia and obesity coexist in patients. The objective of this study was to determine the prevalence of SO under different diagnostic criteria in community-dwelling Spanish adults aged over 65 years residing in Valencia (Spain). The research was conducted as an observational and cross-sectional study with a sample size of 202 subjects. To diagnose sarcopenia, we used the tests proposed by the European Working Group on Sarcopenia in Older People in 2019 (EWGSOP2): SARC-F, grip strength, sit-to-stand, gait speed, Appendicular Skeletal Muscle Mass (ASMM), and Short Physical Performance Battery (SPPB). For obesity diagnosis, we used body mass index (BMI), waist circumference (WC), total body fat percentage (%TBF), and tricipital skinfold (TS). The prevalence of SO was 16.5% in women and 29% in men, according to any of the diagnostic criteria used to determine obesity. A higher proportion of SO was observed as age increased in both groups, although no significant differences were found. Most values obtained in tests related to SO diagnosis were worse in the group affected by the disease; however, there were two exceptions related to the amount of ASMM. In total, 18.8% of the participants presented SO according to any diagnostic criteria related to obesity. Our results suggest significant differences in the number of SO cases depending on diagnostic criteria used to determine the participants' obesity. BMI, WC, and TBF% were shown as principal variables to be included in obesity diagnosis within the SO construct. These findings underscore the need to unify criteria to standardize the diagnosis of SO in the global population.

Hard-to-Heal Wound Healing: Superiority of Hydrogel EHO-85 (Containing Olea europaea Leaf Extract) vs. a Standard Hydrogel. A Randomized Controlled Trial.

Chronic wounds, especially those that are hard-to-heal, constitute a serious public-health problem. Although progress has been made in the development of wound dressings for healing, there is little high-quality evidence of their efficacy, with no evidence of superiority in the use of one hydrogel over another. To evaluate the superiority of a hydrogel (EHO-85), containing Olea europaea leaf extract (OELE), over a standard hydrogel (SH), the promotion and/or improvement of healing of difficult-to-heal wounds was compared in a prospective, parallel-group multicenter, randomized, observer-blinded, controlled trial ("MACAON"). Non-hospitalized patients with pressure, venous or diabetic foot-ulcers difficult-to-heal were recruited and treated with standard care, and EHO-85 (n = 35) or VariHesive (n = 34) as SH. Wound-area reduction (WAR; percentage) and healing rate (HR; mm2/day) were measured. EHO-85 showed a statistically significant superior effect over VariHesive. At the end of the follow-up period, the relative WAR decreased by 51.6% vs. 18.9% (p < 0.001), with a HR mean of 10.5 ± 5.7 vs. 1.0 ± 7.5 mm2/day (p = 0.036). EHO-85 superiority is probably based on its optimal ability to balance the ulcer bed, by modulating pH and oxidative stress. That complements the wetting and barrier functions, characteristics of conventional hydrogels. These results support the use of EHO-85 dressing, for treatment of hard-to-heal ulcers. Trial Registration AEMPS:PS/CR623/17/CE.

Spray Momentum Flux Novel Estimation Procedure through the Fuel Rate of Injection Using Hydrogenated Fuels with Single Hole Nozzle Diesel Injector.

Sustainable means of transport require the innovation or development of propulsive systems more respectful of the environment. Despite current criticism, modern compression-ignition engines are efficient alternatives also in light aviation and surveillance drones (such as small helicopters), as means of air transport. Currently, the improvement of the injection, air-fuel mixture formation, and combustion processes using sustainable synthetic fuels, produced from renewable raw materials or by carbon dioxide capture, is a reality. For improving the air-fuel mixture formation inside the combustion chamber, one of the key parameters is knowledge of the spray momentum flux because of its effect on the air entrainement. To measure this parameter is complex. However, the experimental determination of the fuel mass flow rate is a common procedure. The objective of this work is the proposal of a novel but robust methodology for the momentum flux estimation of fuel sprays from measurement of the rate of injection. In this work, single-hole nozzles of 115, 130, and 150 µm in diameter are studied. The implemented methodology is applied to three fuels: a diesel fuel without biodiesel, used as reference, and two sustainable synthetic fuels: a gas to liquid fuel and a hydrotreated vegetable oil. With the fuel injection rates and the simple model proposed, the spray momentum flux is estimated under different operating conditions of a common-rail injection system. The results of the spray momentum flux show a very good precision compared with those experimentally and previously obtained with similar fuels but with multihole nozzle. With the method proposed in this work, an adequate forecast of spray momentum flux is obtained in the case of not having an experimental setup that allows direct measurement of the momentum flux. This study can help investigators for fuel spray modeling with novel and renewable fuels in modern propulsive systems.