scholarly journals Detection of the stroboscopic effect by young adults varying in sensitivity

2020 ◽  
Vol 52 (6) ◽  
pp. 790-810
Author(s):  
JA Veitch ◽  
C Martinsons
Keyword(s):  
Luminous Flux ◽  
Published Data ◽  
Light Modulation ◽  
Lighting System ◽  
Visual Stress ◽  
Cyclic Variations ◽  
Modulation Signal ◽  
And Performance ◽  
Population Sensitivity ◽  
Glare Sensitivity

The advent of LED lighting has renewed concern about the possible visual, neurobiological, and performance and cognition effects of cyclic variations in lighting system luminous flux (temporal light modulation). The stroboscopic visibility measure (SVM) characterises the temporal light modulation signal to predict the visibility of the stroboscopic effect, one of the visual perception effects of temporal light modulation. A SVM of 1 means that the average person would detect the phenomenon 50% of the time. There is little published data describing the population sensitivity to the stroboscopic effect in relation to the SVM, and none focusing on people subject to visual stress. This experiment, conducted in parallel in Canada and France, examined stroboscopic detection for horizontal and vertical moving targets when viewed under commercially available lamps varying in SVM conditions (SVM: ∼0; ∼0.4; ∼0.9; ∼1.4; ∼3.0). As expected, stroboscopic detection scores increased with increasing SVM. For the horizontal task, average scores were lower than the expected 4/8 at ∼0.90, but increased non-linearly with higher SVMs. Stroboscopic detection scores did not differ between people low and high in pattern glare sensitivity, but people in the high-pattern glare sensitivity group reported greater annoyance in the SVM ∼1.4 and ∼3.0 conditions.

Surgical Drilling: Design and Performance of an Improved Drill

1982 ◽  
Vol 104 (3) ◽  
pp. 245-252 ◽  
Author(s):  
S. Saha ◽  
S. Pal ◽  
J. A. Albright
Keyword(s):  
Compact Bone ◽  
Helix Angle ◽  
Rake Angle ◽  
Peak Temperature ◽  
Published Data ◽  
Drill Bit ◽  
Effective Removal ◽  
Split Point ◽  
And Performance ◽  
Twist Drills

The majority of twist drills used in orthopaedics are very similar to chisel pointed metal drilling bits. Modifications usually observed are reduction of the point angle to 90 deg and sometimes grinding of the entire cutting lip at 0 deg rake angle, which appeared to have been made arbitrarily without any advantage. We have attempted to design a surgical drill bit with the objective of minimization of the drilling thrust and temperature and effective removal of bone chips. Our results showed that the presence of the chisel edge was mainly responsible for increasing the thrust force and the temperature developed. The effects of a constant feed rate and thrust on the peak temperature were also examined. The combined effect of the helix and the point angles on the rake angle which in turn determines the cutting efficiency was analyzed for various types of surgical bits. Based on our results and previously published data from the literature an optimized drill bit was designed with a split point, a point angle of 118 deg, a parabolic flute, and a helix angle of 36 deg and its performance was compared with other existing surgical drill bits. For drilling in compact bone, the new design decreased the thrust load by 45 percent and the peak temperature rise by 41 percent. Simlar improvements were also recorded for drilling bone cement. The time of drilling a bone cortex was also significantly reduced and “walking” on the curved bone surface was eliminated and dimensional tolerance on hole sizes was improved. The new design is likely to reduce the time of surgery and also minimize the tissue damage.

Handball concussion case series in a Brazilian Team

Neurology ◽  
2020 ◽  
Vol 95 (20 Supplement 1) ◽  
pp. S13.1-S13
Author(s):  
Carlos Pinheiro ◽  
Mariana Maciel Fejio
Keyword(s):  
Motor Coordination ◽  
Case Series ◽  
Head Impact ◽  
Published Data ◽  
Symptom Scale ◽  
Cervical Injury ◽  
Brain Concussion ◽  
Single Task ◽  
Falling Asleep ◽  
And Performance

ObjectiveTo analyze the history of self-reported head impacts, prevalence of post-concussion symptoms and performance in motor coordination tests in amateur handball athletes.BackgroundHandball is a contact sport where athletes can suffer collisions through different mechanisms and there are few published data about brain concussion in handball, mainly in Brazilian athletes.Design/MethodsAmateur male athletes aged between 18 and 35 years, with 4–6 hours of training per week and an average of 12.5 games in the last 6 months were evaluated regarding to the head impact history during handball games and practices. The athletes were also evaluated regarding of the most common kind of impact mechanism, loss of consciousness (LOC), reported cervical injury (pain and decreased range of motion), symptoms prevalence and their severity using the Post Concussion Symptom Scale (PCSS), time to execution of single-task tandem gait (TG) and performance in the Finger-to-Nose test (>4 seconds to perform five successive finger to nose repetitions was considered abnormal).ResultsSix athletes reported direct impacts on the head while playing handball. Falls, elbow to the head, trunk to the head and hit by the ball were the most reported mechanisms of head impact in handball athletes. Two athletes reported LOC and all of them denied cervical injury after trauma. Regarding the PCSS score, three athletes had a score between 6-21 and five athletes had a 22–84 score. The most reported symptoms were sleeping more than usual, drowsiness, fatigue, changes in behavior (nervousness, feeling more emotional and irritability), trouble falling asleep and dizziness. However, athletes shown a normal performance in the single task TG (14.6–17.2 seconds) compared to normative data and three athletes shown altered performance on the Finger-to-Nose test.ConclusionsAmateur handball athletes had significant scores of PCSS mainly related to sleep, emotional and possibly to the vestibular function.

Design and Construction of an Automated Hybrid Lighting System

2011 ◽  
Author(s):  
Maria M. Pe´rez Sa´nchez ◽  
Josue´ A. Alonzo Chavarria ◽  
Eduardo E. Ordon˜ez Lo´pez
Keyword(s):  
Luminous Flux ◽  
Natural Light ◽  
Artificial Light ◽  
Lighting System ◽  
Light Emitting ◽  
System Components ◽  
Lighting Systems ◽  
Signal Conditioning Circuit ◽  
Conditioning Circuit ◽  
Design And Construction

The lighting systems of homes and workplaces today must be constantly redesigned to be environmentally friendly, sustainable, healthy and ergonomic. This requires maximizing the flow of daylight into indoors, minimizing the amount of pollutants used in their manufacture, long durability materials considered in the design, maximizing energy efficiency of the lighting system components, mimicking the spectrum of natural light and providing some control of lighting modes by the user. Taking into account all these considerations, it is proposed the design and construction of an intelligent lighting system that regulates the use of natural and artificial light, prioritizing the availability of the former over the latter in order to be implemented in housing in the region of the Yucata´n peninsula. To achieve this goal, it is designed and built a light sensor with its own signal conditioning circuit, a light tube of stainless steel with luminous flux control, a dimming circuit for a lamp that uses light-emitting diodes (LEDs) and a control system with a PIC18f4550 micro controller.

scholarly journals EMPLOYEE PERCEPTION AND PERFORMANCE APPRAISAL: AN EVALUATION OF SELECTED DEPOSIT MONEY BANKS IN PORT HARCOURT

2020 ◽  
pp. 80-95
Author(s):  
Bienwi-Patrick, Ledum ◽  
B. Chima Onuoha ◽  
Best C. Eke
Keyword(s):  
Procedural Justice ◽  
Performance Appraisal ◽  
Pay For Performance ◽  
High Rate ◽  
Published Data ◽  
Employee Perception ◽  
Appraisal System ◽  
Port Harcourt ◽  
Performance Appraisal System ◽  
And Performance

Performance Appraisal system represents a major tool for most of the organizations to evaluate various aspects of their employees. Despite the prominence of the organizational phenomenon, very limited research is done in Nigerian organization in this area .To analyses the perception of employees regarding the performance appraisal system implementation, the Deposit Money Banks in Port Harcourt, Rivers state are selected due to the reported high rate of staff turnover. In order to analyze the perception of employees regarding the new system and its implementation, 33 item questionnaires consist of 4 independent and one dependent variables was distributed among 150 employees who were acquainted with the Performance appraisal procedure. The study employed four measures of performance appraisal which are Procedural justice, Goal setting, feedback and Pay for performance and one criterion variable, the employee perception towards these performance appraisal process. The instrument used was a 5 point Likert scale questionnaire. Factor analysis and regression analysis was done through the Statistical Package for Social Sciences version 25.The result shows the process was implemented as per organization guidelines to the overall satisfaction of employees. There are however some areas of improvement which have been noted in the conclusion. The results and outcome are in line with international published data. KEYWORDS: Employee Perception, Performance Appraisal, Procedural Justice.

Detrimental or beneficial? Untangling the literature on developmental stress studies in birds

2021 ◽  
Vol 224 (19) ◽  
Author(s):  
Haruka Wada ◽  
Victoria Coutts
Keyword(s):  
Developmental Plasticity ◽  
Published Data ◽  
Developmental Stress ◽  
Physiological Functions ◽  
Thrifty Phenotype ◽  
Physiological Variables ◽  
Stress Studies ◽  
Organ Systems ◽  
And Performance ◽  
The Individual

ABSTRACT Developing animals display a tremendous ability to change the course of their developmental path in response to the environment they experience, a concept referred to as developmental plasticity. This change in behavior, physiology or cellular processes is primarily thought to allow animals to better accommodate themselves to the surrounding environment. However, existing data on developmental stress and whether it brings about beneficial or detrimental outcomes show conflicting results. There are several well-referred hypotheses related to developmental stress in the current literature, such as the environmental matching, silver spoon and thrifty phenotype hypotheses. These hypotheses speculate that the early-life environment defines the capacity of the physiological functions and behavioral tendencies and that this change is permanent and impacts the fitness of the individual. These hypotheses also postulate there is a trade-off among organ systems and physiological functions when resources are insufficient. Published data on avian taxa show that some effects of developmental nutritional and thermal stressors are long lasting, such as the effects on body mass and birdsong. Although hypotheses on developmental stress are based on fitness components, data on reproduction and survival are scarce, making it difficult to determine which hypothesis these data support. Furthermore, most physiological and performance measures are collected only once; thus, the physiological mechanisms remain undertested. Here, we offer potential avenues of research to identify reasons behind the contrasting results in developmental stress research and possible ways to determine whether developmental programming due to stressors is beneficial or detrimental, including quantifying reproduction and survival in multiple environments, measuring temporal changes in physiological variables and testing for stress resistance later in life.

scholarly journals Outdoor testing of photovoltaic modules during summer in Taxila, Pakistan

2016 ◽  
Vol 20 (1) ◽  
pp. 165-173 ◽  
Author(s):  
Hafiz Ali ◽  
Mubashar Mahmood ◽  
Muhammad Bashir ◽  
Muzaffar Ali ◽  
Aysha Siddiqui
Keyword(s):  
Amorphous Silicon ◽  
Operating Conditions ◽  
Performance Ratio ◽  
Published Data ◽  
Photovoltaic Modules ◽  
Efficiency Performance ◽  
Higher Temperature ◽  
Low Efficiency ◽  
And Performance ◽  
Module Efficiency

An experimental study has been carried out to measure the performance of commercially available photovoltaic modules during summer months in the climate of Taxila, near the capital of Pakistan. The modules used in the study are monocrystalline silicon (c-Si), polycrystalline silicon (p-Si) and single junction amorphous silicon (a-Si). The analysis has been focused on the measurement of module efficiency, performance ratio and temperature of each module at actual operating conditions using outdoor monitoring facility. The measured results are compared with the already published data of peak winter month at the same site. Overall, the monocrystalline module showed high average module efficiency while amorphous silicon module was better in term of average performance ratio. Furthermore, the module efficiency and performance ratio has shown decreasing trend with increase of module temperature. It was found that modules have much higher temperature in summer months (about 20?C higher) and showed low efficiency and performance ratio than peak winter month. The average ambient temperature varied from 18.1?C to 38.6?C from winter to summer.

Noise-Modulated Correlation Measuring and Performance Analysis

2014 ◽  
Vol 1030-1032 ◽  
pp. 1741-1744
Author(s):  
Cheng Hong Zhou ◽  
Wei Ping Qian ◽  
Hua Zhao ◽  
Jun Hai Guo
Keyword(s):  
Performance Analysis ◽  
Electromagnetic Waves ◽  
Estimation Methods ◽  
Motion Information ◽  
Process Noise ◽  
Signal Noise ◽  
Noise Radar ◽  
Continuous Waves ◽  
Modulation Signal ◽  
And Performance

Radar obtains motion information of target from received modulated electromagnetic waves, which is usually periodical pulses or continuous waves. In this process, noise will affect the detection performance. However, as a modulated transmitting signal, noise has incomparable advantages over traditional radar. In this article, the mechanism of noise as modulation signal is introduced, and subsequently focused on the principles of distance ranging the corresponding estimation methods are proposed. Besides, the interference resistance characters of noise radar is verified by simulation.

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