2,512 research outputs found
Analysis of environmental conditions in two different Compost Bedded Pack Barn systems for dairy cattle
Received: February 1st, 2023 ; Accepted: April 27th, 2023 ; Published: May 10th, 2023 ; Correspondence: [email protected], [email protected] objective of this study was to analyse and compare the thermal environment of
dairy cattle facilities in an open compost bedded pack barn (CBP) with natural ventilation and
closed CBP (without thermal insulation) and climate control system. The research was conducted
in a property located in Zona da Mata, Minas Gerais, Brazil. During the summer and for different
periods of the day, the following average environmental variables observed inside the facilities
were measured: dry bulb temperature, relative humidity and Temperature and Humidity Index
(THI). The results were submitted to an analysis of variance to determine the significance of the
variables in the different treatments. It was found that the closed and climate control system CBP
promoted greater control of the facility's internal microclimate, registering smaller thermal
amplitudes and a greater reduction in the animals' exposure time to stressful thermal conditions,
compared to the CBP with natural ventilation. However, during summer afternoons, comfort
indices indicated moderate stress. It is concluded that the closed CBP, regarding the analysed
variables, indicated potential use, provided that a careful study of the climate of the region is
carried out before implementation, the factors related to the ambient conditioning and better
insulation of the construction are adjusted. The climatic variables inside the open CBP indicated
a high stress condition for the animals, suggesting the placement of positive pressure fans and
sprinklers properly distributed in the feed alley, to guarantee benefits to the entire area of the
animal housing
Profile of female swimmers competing in the 50 m events at the 2021 LEN European Championships
This study aimed to understand whether there are significant differ-
ences in stroke kinematics between tiers in female swimmers com-
peting in the four 50 m events of the 2021 European Championships
and to understand the speed-time relationship in the four race events
per tier. Participants were all female swimmers (backstroke: 78 swim-
mers; breaststroke: 75 swimmers; butterfly: 74 swimmers; freestyle:
87 swimmers) who participated in the 50 m events at the 2021 LEN
European Championships held in Budapest (i.e. heats, semi-finals,
and final). For each swimming stroke, swimmers were divided into
three tiers (best-performing swimmers, intermedium-performing
swimmers, and poorest-performing swimmers). Swimming speed
revealed a significant tier effect (p < 0.05) in all race sections for all
swimming strokes. The other stroke kinematic variables revealed
divergent findings, but the stroke frequency presented an overall
tier effect (p < 0.05) across all four swimming strokes. Curve fitting for
all swimming strokes and tiers revealed a cubic relationship. Thus, it
should be considered that female swimmers who compete in 50 m
events in major competitions adopt an all-out strategy. The present
data provide coaches with insightful information about the main
trend in 50 m sprint events, specifically in each section of the race.The work was supported by the Fundação para a Ciência e a Tecnologia [UIDB/DTP/04045/2020].info:eu-repo/semantics/publishedVersio
Using lean thinking principles to reduce wastes in reconfiguration of car radio final assembly lines
Assembly lines are production systems designed to be oriented to the product and well known to be highly productive. Nevertheless, during this time-frame the product volumes could decrease and the assembly lines, previously very productive and efficient, becomes unproductive and inefficient. This happens in the car electronics components company where this study took place that due to customer's demand decrease, produced volumes also decreased and provoked the appearance of wastes related with too much occupied space, unbalanced workstations, more capacity than needed, outdated standard work sheets, bottlenecks, to conclude, too many non-added value activities. This paper presents a reconfiguration proposal for two final assembly lines with the goal of adapt physically the lines to the actual production volumes and eliminate the existing wastes. The proposed reconfiguration translates into very positive gains for the company, namely, the release of 22% of the space occupied by the production lines, a reduction in the number of operators, a 50% increase in productivity for each of the lines and an increase in the utilization rate (23% for line 1 and 13% for line 2). In total, the monetary gains associated with these improvements were, approximately, of 125,600 m.u. per year.Special thanks to engineer Hugo Moreira for all the advice given for the development of this project. Also, thanks to the company for all the cooperation and opportunity to apply knowledge acquired during the academic years. This work has been supported by FCT – Fundação para a Ciência e Tecnologia within the Project Scope: UID/CEC/00319/2019
Relationships between head-out aquatic exercise kinematics and musical cadence: analysis of the side kick
Background: Head-out aquatic exercises became one of the most popular physical activities within the health primarily and thirdly prevention system. Music is seen as one of the most important aspects when conducting head-out aquatic exercise sessions. Research question: Is there any relationship between musical cadence and the kinematic behaviour when performing aerobic head-out aquatic exercises? It was hypothesized that an increase in music cadence will would impose a decrease of the segment range of motion. Type of study: Experimental, prospective. Methods: Six young and clinically healthy women with at least one year of experience conducting head-out aquatic classes were videotaped in the frontal plane, with a pair of cameras providing a double projection (above and below the water surface). Subjects performed an incremental protocol of five bouts (120b.min-1, 135b.min-1, 150b.min-1, 165b.min-1 and 180b.min-1) with 16 full cycles of the “side kick” exercise. Data processing and calculation of segmental (i.e. hands and feet) and anatomical landmark (i.e. centre of mass) were performed using the software Ariel Performance Analysis System and applying the DLT algorithm. Results: There was a decrease in the cycle period during the incremental protocol. The relationships between the segmental lateral and vertical displacements with the musical cadence were not significant. The segmental velocities on the lateral and vertical components showed significant increases throughout the incremental protocol. Conclusions: The data suggest that segmental velocity increases with increasing cadence, reducing the cycle period and maintaining the segmental displacements
Head-out aquatic exercise “sailor’s jigs” kinematics at increasing musical cadence
The aim of this study was to analyze the relationships between “Sailor’s jigs” kinematic and increasing music cadence. Six young women with at least one year of experience conducting this type of head-out aquatic programs, with no kind of skeletal muscle injury reported on the last six months and non-pregnant were evaluated. The exercise was recorded on video, in the frontal plane, using a pair of cameras, enabling a double projection, from above and underwater body motions, at five increasing cadences (120 b.min-1, 135 b.min-1, 150 b.min-1, 165 b.min-1 and 180 b.min-1). Images were thereafter digitized in specific software (Ariel Performance Analysis Systems). The cycle period decreased through the incremental protocol. Cycle period decrease is done decreasing joints range of motion and increasing the limbs segmental velocity as well. Although these combined kinematical strategy, a deeper analysis reveals that subjects decrease the cycle period mainly decreasing the range of motions
Head-out aquatic exercise “sailer’s jigs” kinematics at increasing musical cadence
The aim of this study was to analyze the relationships between
“Sailor’s jigs” kinematics and increasing music cadence. Six young
women, non-pregnant, with at least one year of experience conducting
this type of head-out aquatic program, with no kind of skeletal
muscle injury reported in the last six months were evaluated. The
exercise was recorded on video, in the frontal plane, using a pair of
cameras, enabling a double projection, from above and underwater
body motions, at five increasing cadences (120 b.min-1, 135 b.min-1,
150 b.min-1, 165 b.min-1 and 180 b.min-1). Images were thereafter
digitized in specific software (Ariel Performance Analysis Systems).
The cycle period decreased through the incremental protocol. Cycle
period decrease is done decreasing joint range of motion and increasing
the limbs segmental velocity as well. Although these combined
kinematical strategy, a deeper analysis reveals that subjects decrease
the cycle period mainly decreasing the range of motion
Normative data of the start in the 50 m events at the 2021 LEN European Championships and understanding its relationship with the final race
This study aimed to: (i) present normative data of the variables related to the start in
the four swim strokes by tier and sex, and; (ii) understand the relationship between the 15th
meter mark time and the final race time of the male and female swimmers competing in the four
50 m events at the 2021 European Championships. Participants were all male and female
swimmers who competed in the 50 m events at the 2021 LEN European Championships held in
Budapest. The official race times and block times were retrieved from the official competition
website. All starting variables were analyzed in a dedicated software for race analysis. The 15th
meter mark time was used as the start main outcome. For all events by sex, the 15th meter mark
time was the variable presenting the highest and largest tier effect (p < 0.001) besides the final
race time. Overall, despite the swim stroke, the variables related to the underwater phase were
also responsible for the significant tier effect (p < 0.001). The 15th meter mark time presented a
high to very-high relationship with the final race time in all four swim strokes. This relationship
was stronger in freestyle (both sexes). That is, swimmers who achieve the 15th meter mark sooner
are more likely to deliver better performances. Coaches must be aware that the underwater
phase plays a key-role on the swimmers’ (both sexes) start performance. Nonetheless, different
strategies can be used based on the swimmers’ strength and weaknesses. Moreover, the start
performance in all four swim strokes and in both sexes can strongly predict the final race time.This research was supported by national funds (FCT - Portuguese Foundation for Science
and Technology) under the project UIDB/DTP/04045/2020info:eu-repo/semantics/publishedVersio
Kinematical characterisation of a basic head-out aquatic Exercise during an incremental protocol
The aim of this study was to analyze the relationships between musical cadence and kinematical characteristics of a basic head-out aquatic exercise. Six young women with at least one year of experience conducting head-out aquatic classes were videotaped in the sagital plane with a pair of cameras providing a dual projection from both above and underwater performing 5 incremental bouts (120, 135, 150, 165 and 180 b.min-1) of the basic head-out aquatic exercise “rocking horse”. There was a decrease of the cycle period throughout the protocol. Relationships between horizontal or vertical displacements with music cadence were not significant. Increased cadence imposed increased segmental and centre of mass’ velocities. As a conclusion expert and fit subjects seem to increase segmental velocity with increasing musical cadence
Kinematical characterization of the basic head-out aquatic exercise “Sailor’s Jigs”
Massive research has been produced
throughout the last decades in order to
be@er understand the role of head-out
aquatic exercises in populations’ health
(Barbosa et al, 2009). Indeed, such studies
aimed to characterize the physiological
acute and/or chronic response of subjects
performing head-out aquatic exercises.
Moreover, the comprehensive knowledge
about the biomechanical (i.e. kinematical)
behavior performing this aquatic actvity is
quite reduced.info:eu-repo/semantics/publishedVersio
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