Optimized Energy Management Strategy for Wind Plants with Storage in Energy and Reserve Markets

This paper addresses the joint operation of wind plants with energy storage systemsin multiple markets to increase the value of wind energy from an economic and technical point of view. The development of an optimized energy management allows scheduling the wind generation in energymarkets, as well as contributing to the system stability through the joint participation in frequency ancillary services. The market optimization maximizes market revenuesconsidering overallstoragecosts, while avoidingenergy imbalancesand market penalties. Moreover, wind power fluctuations, forecast errors and real-time reserverequirementsare controlledby the energy storagesystem and managed afterward through the participation in continuous intraday market. Furthermore, model predictive control approach enables a high compliance of reserve requirementsand a hugereduction of energy imbalancesin real-time operation. Different energy storagecapacities are selected in order to evaluate theircost-effectiveness enhancing the wind plant operation underthe considered study case.This work was partially supported by the Basque Government under Project Road2DC (ELKARTEK Research Program KK-2018/00083)

Učinci šest tjedana treninga dubinskih skokova i skokova s pripremom na pijesku na mišićni zamor i izvedbu

The purpose of this study was to examine the effects of six weeks of depth jump (DJ) vs countermovement jump (CMJ) training on sand on muscle soreness, jump, sprint, agility and leg press strength. Thirty healthy men (age 20.4±1.1 years; height 177.4±5.1 cm; and mass 72.8±9.7 kg) volunteered to participate and were randomly assigned to one of three groups: DJ training group (n=10), CMJ training group (n=10) or control group (n=10). The experimental groups performed either DJ or CMJ training two days a week for six weeks. The training program included five sets of 20 repetitions DJ (from the height of a 45-cm box) or CMJ exercise onto 20 cm of dry sand. Assessments of Vertical Jump Test (VJT), Standing Long Jump Test (SLJT), 20 and 40 m sprints, T-Test (TT), Illinois Agility Test (IAT), and one-repetition maximum Leg Press (1RMLP) were performed a week before and following the 6-week training period. Muscle soreness was also measured pre, immediately post, 24 and 48 hours after the first and last training sessions. Significant increases were observed in both the DJ and CMJ groups in VJT (16.2 vs. 13.5%), and SLJT (13.9 vs. 14.4%) (p.05). These observations may have considerable practical relevance for the optimal design of plyometric training programs, given that DJ and CMJ training on sand is effective for improving muscular performance.Cilj je ovog istraživanja bio utvrditi učinke šestotjednog treninga dubinskih skokova u odnosu na skokove s pripremom na pijesku na mišićni zamor, izvedbu skokova, sprinta, agilnost i snagu nožnog potiska. Za sudjelovanje u istraživanju volontiralo je 30 ispitanika (dob: 20,4±1,1 godina; tjelesna visina: 177,4±5,1 cm; tjelesna težina: 72,8±9,7 kg) koji su slučajnim odabirom raspoređeni u jednu od tri grupe: grupu koja je trenirala dubinske skokove (n=10), grupu koja je trenirala skokove s pripremom (n=10) ili kontrolnu grupu (n=10). Ispitanici u eksperimentalnim grupama provodili su trening dubinskih skokova ili trening skokova s pripremom dva puta tjedno tijekom šest tjedana. Program treninga uključivao je pet serija po 20 ponavljanja dubinskih skokova (saskok sa sanduka visine 45 cm) ili skokova s pripremom na suhom pijesku dubine 20 cm. Tjedan dana prije treninga te nakon šest tjedana treninga provedena su mjerenja visine vertikalnog skoka, skoka udalj s mjesta, sprinta na 20 i 40 metara, razine agilnosti pomoću T-testa i Illinois Agility Testa te 1RM u testu nožni potisak. Razina mišićnog zamora također je bila mjerena prije, odmah nakon, 24 i 48 sati nakon prvog i posljednjeg treninga. Značajna povećanja u visini vertikalnog skoka (16,2 vs. 13,5%) i skoku udalj s mjesta (13,9 vs. 14,4%) (p<0,05) zabilježena su u grupi koja je trenirala dubinske skokove, odnosno skokove s pripremom. Značajna smanjenja vremena sprinta na 20 (8,5 vs. 7,4%) i 40 (6,1 vs. 3,8%) metara, T-testu (9,3 vs. 12%) i Illinos Agility Testu (9,2 vs. 10,6%) zabilježena su u obje eksperimentalne grupe. Značajno povećanje 1RM u testu nožni potisak zabilježeno je samo u grupi koja je provodila trening skokova s pripremom. Ista grupa zabilježila je i statistički značajno veći osjećaj mišićnog zamora u mišiću rectus femoris 48 sati nakon prvog treninga nego grupa koja je provodila trening dubinskih skokova i kontrolna grupa. Nisu zabilježene statistički značajne razlike u osjećaju zamora između grupa nakon posljednjeg treninga. Rezultati ovog istraživanja mogu pridonijeti dizajniranju optimalnih programa pliometrijskog treninga, s obzirom na činjenicu da su oba eksperimentalna tipa treninga na pijesku pokazala učinkovitost u poboljšanju mišićnih performansi

Comparison of two 8-week training interventions on the athletic performance of padel players

Padel is an intermittent racket sport played in pairs (2 vs. 2) on a small-sized grass court (20 x 10 m), involving high physical fitness demands for the players. Therefore, this study aims to compare the effect of two 8-week in-season training programs on the athletic performance of male padel players. Participants (age, 22.1±0.8 yr; body height, 182.0±1.0 cm ; body mass, 74.7±0.7 kg) were randomly assigned to the integrated training group (IG, n=12) and non-integrated training group (NIG, n=12). The IG trained inside the padel court, integrating neuromuscular exercises with sport-specific (i.e., use of the racket) technical actions. The NIG trained outside the padel court, performing the same neuromuscular exercises and sport-specific technical actions as the IG, although not simultaneously. Before and after the intervention, athletes were assessed for their hand-grip strength, two legged and one-legged Abalakov jump, bench press performance, padel stroke velocity, cardiorespiratory endurance (30-15IFT), 5-m and 10-m linear sprint time and change of direction ability at 90º and 180º using left and right leg. Both groups improved their scores on Abalakov jump tests, bench press performance, stroke velocity, cardiorespiratory endurance (30-15IFT), and change of direction ability at 90º and 180º (all changes p<.05; effect size = 0.22-2.58). The IG improved stroke velocity compared to NIG (p<.05), and only the IG showed pre-post improvements (p<.05; effect size = 0.30-0.76) in change of direction ability at 90º and 180º involving the non-dominant leg (i.e., turn to the right). An 8-week in-season integrated training approach and a non-integrated training approach may induce similar improvements in athletic performance among highly trained male padel players. However, the neuromuscular training program involving an integration of padel-specific and non-specific training exercises may induce greater improvements in padel-specific performance (i.e., stroke velocity) and change of direction speed ability, particularly in movements involving the non-dominant leg

Effects of Maturation on Physical Fitness Adaptations to Plyometric Drop Jump Training in Male Youth Soccer Players

The objective of this study was to compare the effects of maturation on physical fitness adaptations to a twice weekly, 7-week plyometric drop jump training program. Seventy-six young male soccer players (aged 10–16 years) participated in this randomized controlled trial. Before and after the intervention, a physical fitness test battery was applied (countermovement jump; drop jump from 20 to 40 cm; 5 multiple bounds test; 20-m sprint time; change of direction speed; 2.4-km running time-trial; 5 repetition maximum [RM] squat; and maximal kicking distance). Participants were randomly divided into an active soccer-control group (CG) with Tanner stage maturation of 1–3 (CG-early; n = 16) or Tanner stage 4–5 (CG-late; n = 22), and to plyometric drop jump training groups with Tanner stage 1–3 (plyometric jump training [PJT]-early; n = 16) or 4–5 (PJT-late; n = 22). The analysis of variance and effect size (ES) measures revealed that when compared with their age-matched controls, the PJT-early (ES = 0.39–1.58) and PJT-late (ES = 0.21–0.65) groups showed greater improvements (p < 0.05) in sprint time, 2.4-km running time-trial, change of direction speed, 5RM squat, jumping, and kicking distance. The PJT-early exceeded the PJT-late group with greater (p < 0.05) improvements in drop jump from 20 cm (ES = 1.58 vs. 0.51) and 40 cm (ES = 0.71 vs. 0.4) and kicking distance (ES = 0.95 vs. 0.65). Therefore, a 7-week plyometric drop jump training program was effective in improving physical fitness traits in both younger and older male youth soccer players, with greater jumping and kicking adaptations in the less-mature athletes

The effects of combined balance and complex training versus complex training only on measures of physical fitness in young female handball players

To examine the effects of balance exercises conducted prior to complex training (bCT) versus complex training (CT) only on measures of physical fitness in young female elite handball players. Methods: Participants aged 17 years were randomly assigned to bCT (n = 11) or CT (n = 12). The 2 training interventions lasted 8 weeks with 2 sessions per week in replacement of some technical/tactical handball exercises and were matched for total training volume. Before and after training, tests were performed for the evaluation of proxies of muscle power (countermovement jump height, standing long-jump distance, and reactive strength index), muscle strength (back half-squat 1-repetition maximum), dynamic balance (Y-balance test), linear sprint speed (20-m sprint test), and change-of-direction speed (T test). Results: Two-factor repeated-measures analysis of variance revealed significant group × time interactions for the reactive strength index (d = 0.99, P = .03) and Y-balance test score (d = 1.32, P < .01). Post hoc analysis indicated significant pre–post reactive strength index improvements in CT (d = 0.69, P = .04) only. For the Y-balance test, significant pre–post increases were found in bCT (d = 0.71, P = .04) with no significant changes in CT (d = 0.61, P = .07). In addition, significant main effects of time were observed for half-squat 1-repetition maximum, countermovement jump, standing long jump, and T test performance (d = 1.50 to 3.10, P < .05). Conclusions: Both bCT and CT interventions were effective in improving specific measures of physical fitness in young elite female handball players. If the training goal is to improve balance in addition, balance exercises can be conducted within a CT training session and prior to CT exercises

A comparison of catch phase force-time characteristics during clean derivatives from the knee

The aim of this study was to compare load-absorption force-time characteristics of the clean from the knee (CK), power clean from the knee (PCK) and clean pull from the knee (CPK). Ten collegiate athletes (age 27.5 ± 4.2 years; height 180.4 ± 6.7 cm; mass 84.4 ± 7.8 kg), performed three repetitions each of the CK, PCK and CPK with 90% of their 1RM power clean on a force platform. The CK load-absorption duration (0.95 ± 0.35 s) was significantly longer compared to the CPK (0.44 ± 0.15 s; p 0.05, d = 1.08), with no differences between PCK and CPK (p > 0.05, d = 0.91). The CPK demonstrated the greatest mean force (2039 ± 394 N), which was significantly greater than the PCK (1771 ± 325 N; p = 0.012, d = 0.83), but not significantly different to the CK (1830 ± 331 N; p > 0.05, d = 0.60); CK and PCK were not different (p > 0.05, d = 0.18). Significantly more load-absorption work was performed during the CK (655 ± 276 J) compared to the PCK (288 ± 109 J; d = 1.75, p 0.05). Additionally, more load-absorption work was performed during the CPK compared to the PCK (d = 1.90, p = 0.032). Inclusion of the catch phase during the CK does not provide any additional stimulus in terms of mean force or work during the load-absorption phase compared to the CPK, while the CPK may be beneficial in training rapid force absorption due to high force and a short duration

Trends and outcome of neoadjuvant treatment for rectal cancer: A retrospective analysis and critical assessment of a 10-year prospective national registry on behalf of the Spanish Rectal Cancer Project

Introduction: Preoperative treatment and adequate surgery increase local control in rectal cancer. However, modalities and indications for neoadjuvant treatment may be controversial. Aim of this study was to assess the trends of preoperative treatment and outcomes in patients with rectal cancer included in the Rectal Cancer Registry of the Spanish Associations of Surgeons. Method: This is a STROBE-compliant retrospective analysis of a prospective database. All patients operated on with curative intention included in the Rectal Cancer Registry were included. Analyses were performed to compare the use of neoadjuvant/adjuvant treatment in three timeframes: I)2006–2009; II)2010–2013; III)2014–2017. Survival analyses were run for 3-year survival in timeframes I-II. Results: Out of 14, 391 patients, 8871 (61.6%) received neoadjuvant treatment. Long-course chemo/radiotherapy was the most used approach (79.9%), followed by short-course radiotherapy ± chemotherapy (7.6%). The use of neoadjuvant treatment for cancer of the upper third (15-11 cm) increased over time (31.5%vs 34.5%vs 38.6%, p = 0.0018). The complete regression rate slightly increased over time (15.6% vs 16% vs 18.5%; p = 0.0093); the proportion of patients with involved circumferential resection margins (CRM) went down from 8.2% to 7.3%and 5.5% (p = 0.0004). Neoadjuvant treatment significantly decreased positive CRM in lower third tumors (OR 0.71, 0.59–0.87, Cochrane-Mantel-Haenszel P = 0.0008). Most ypN0 patients also received adjuvant therapy. In MR-defined stage III patients, preoperative treatment was associated with significantly longer local-recurrence-free survival (p < 0.0001), and cancer-specific survival (p < 0.0001). The survival benefit was smaller in upper third cancers. Conclusion: There was an increasing trend and a potential overuse of neoadjuvant treatment in cancer of the upper rectum. Most ypN0 patients received postoperative treatment. Involvement of CRM in lower third tumors was reduced after neoadjuvant treatment. Stage III and MRcN + benefited the most

Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).

Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and ≥1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (n = 5069) or prospectively (n = 5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (≤6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; p = 0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)