Acrylate oligomers in ultraviolet cured PSA's glass transition, molecular weight versus peel strength

International Nuclear Information System (INIS)

Miller, H.C.

1999-01-01

Typically those not skilled in the art relate Glass Transition Temperature to Pressure Sensitive Adhesives. You need a low Tg material to prepare good pressure sensitive adhesives. This report deals with a wide range acrylate terminated oligomers in a standard formulation. Molecular weight, chemical structure variations are examined versus the Glass Transition of the oligomers and final peel strength. Each formulated adhesive will require unique oligomer properties to reach one hundred newtons per 100 millimeters (5.71 pounds per square inch) peel strength. Excellent peel strengths may be obtained with oligomer molecular weight ranging from six thousand to one thousand molecular weight and glass transition temperatures ranging from minus seventy four degrees centigrade up to thirteen degrees centigrade

Light Weight Deflectometer (LWD)

OpenAIRE

Siddiki, Nayyar Zia

2012-01-01

Light weight deflectometer (LWD) has been widely used for quality assurance in road construction, in particular compaction of both chemically treated subgrade soil and aggregate subbase. However, it has been recognized that LWD measurements vary with many factors. Based on LWD tests in actual road construction, this presentation provides updated information on the LWD deflection measurements for both chemically treated subgrade soil and aggregate subbase.

Impact strength on fiber-reinforced hybrid composite

International Nuclear Information System (INIS)

Firdaus, S M; Nurdina; Ariff, M Azmil

2013-01-01

Acrylonitrile-Butadiene-Styrene (ABS) has been well known composite in automotive players to have light weight with high impact strength material compared to sheet metal material which has high impact strength but heavy in weight. In this project, the impact strength properties of fabricated pure ABS were compared to the eight samples of hybrid ABS composite with different weight percentages of short fibers and particle sizes of ground rubber. The objective was to improve the impact strength in addition of short fibers and ground rubber particles. These samples were then characterized using an un-notched Izod impact test. Results show that the increasing of filler percentage yielded an adverse effect on the impact strength of the hybrid composite. The effect of the ground rubber particulate sizes however are deemed to be marginal than the effect of varying filler percentage based on the collected impact strength data from all physically tested hybrid composites

Changes in muscle strength after diet-induced weight reduction in adult men with obesity: a prospective study

Directory of Open Access Journals (Sweden)

Kim B

2017-05-01

Full Text Available Bokun Kim,1 Takehiko Tsujimoto,2,3 Rina So,4 Xiaoguang Zhao,5 Sechang Oh,6,7 Kiyoji Tanaka2 1Faculty of Sports Health Care, Inje University, Gyeongsangnamdo, Republic of Korea; 2Faculty of Health and Sport Sciences, University of Tsukuba, Ibaraki, 3Faculty of Human Sciences, Shimane University, Shimane, 4Research Center for Overwork-Related Disorders, National Institute of Occupational Safety and Health, Kawasaki, Kanagawa, 5Doctoral Program in Sports Medicine, Graduate School of Comprehensive Human Sciences, 6Faculty of Medicine, University of Tsukuba, 7The Center of Sports Medicine and Health Sciences, University of Tsukuba Hospital, Tsukuba, Ibaraki, Japan Background and objective: The benefits of weight reduction for musculoskeletal disorders are well understood. Steep declines in muscle mass following considerable weight reduction can decrease muscle strength and, consequently, physical performance. However, only a limited number of studies have examined the changes in muscle mass and strength in the context of interventional weight reduction programs. Thus, we investigated the influence of muscle mass decrease caused by diet-induced weight reduction on muscle strength in obese men.Methods: A total of 24 men with obesity (body mass index [BMI]: 29.2 ± 2.6 kg/m2; age: 52.4 ± 10.0 years attended a 12-week weight reduction program that implemented dietary restrictions. Each participant underwent assessments of body weight (by a digital scale, body composition (by whole-body dual-energy X-ray absorptiometry [DEXA], and upper and lower extremity muscle strength (by a hand-held dynamometer and a Biodex System 3 dynamometer, respectively before and after the program.Results: The program led to significant reductions of 10.5% of weight and 6.1% of lower extremity muscle mass. Similarly, lower extremity muscle strength (measured using a Biodex System 3 dynamometer was significantly decreased (isometric 60° peak torque decreased by 10% and

Bright Light for Weight Loss: Results of a Controlled Crossover Trial

Directory of Open Access Journals (Sweden)

Konstantin V. Danilenko

2013-02-01

Full Text Available Objective: To investigate whether bright light treatment can reduce body mass in overweight subjects irrespective of their seasonal (= light dependence. Methods: A crossover, placebo-controlled, randomized clinical trial was performed between November and April in Novosibirsk, Russia (55° N. The trial comprised a 3-week in-home session of morning bright light treatment using a device of light-emitting diodes and a 3-week placebo session by means of a deactivated ion generator, separated by an off-protocol period of at least 23 days. The number of placebo and light sessions was matched with respect to season. Data were obtained from 34 overweight women, aged 20-54 years, 10 were seasonal-dependent according to the Seasonal Pattern Assessment Questionnaire. Weekly measures included body weight, percentage body fat by bioimpedancemetry, and subjective scores (appetite, mood, energy levels. Results: Motivation and expectation towards weight loss were similar for the two intervention sessions. With light, compared to the placebo session, weight did not reduce significantly, but percentage fat, fat mass, and appetite were significantly lower (average fat reduction 0.35 kg. The latter two results remained significant after excluding seasonal-dependent subjects from the analysis. Irrespective of the type of intervention, seasonal-dependent subjects had greater weight and fat mass changes during treatment (decline p 0.036 or between sessions (regain p 0.003. Photoperiod (p = 0.0041, air temperature to a lesser extent (p = 0.012, but not sunshine (p = 0.29 was associated with the weight change (greater weight reduction if the second session was in spring. Conclusion: Morning bright light treatment reduces body fat and appetite in overweight women and may be included in weight control programs.

HOKES/POKES : Light-weight resource sharing

NARCIS (Netherlands)

Bos, Herbert; Samwel, Bart

2003-01-01

In this paper, we explain mechanisms for providing embedded network processors and other low-level programming environments with light-weight support for safe resource sharing. The solution consists of a host part, known as HOKES, and a network processor part, known as POKES. As common operating

Weight, body composition and handgrip strength among pulmonary tuberculosis patients

DEFF Research Database (Denmark)

Praygod, George; Range, Nyagosya; Faurholt-Jepsen, Daniel

2011-01-01

This study aimed to estimate deficits in weight, arm fat area (AFA), arm muscle area (AMA) and handgrip strength among smear-positive pulmonary TB (PTB+) patients starting treatment. We conducted a cross-sectional study among PTB+ patients and age- and sex-matched neighborhood controls. HIV statu...

Literature Review of Shear Performance of Light-weight Steel Framing Wall Panels

Science.gov (United States)

Zhang, Zhuangnan; Liu, Shen; Liu, Hong

2018-03-01

In this paper, a comprehensive review of light-weight steel framing wall panels was carried out. The structure and force characteristics of light-weight steel framing wall panels were introduced. The testing and theoretical research results on the shear behaviour of light-weight steel framing wall panels were summarized in the domestic and foreign. And combined with the existing standards in China, the author's views and ideas are put forward to the problems in the research field of this kind of structural system.

A comparative evaluation of the shear bond strength of five different orthodontic bonding agents polymerized using halogen and light-emitting diode curing lights: An in vitro investigation

Directory of Open Access Journals (Sweden)

Sujoy Banerjee

2011-01-01

Full Text Available Purpose: With the introduction of photosensitive (light-activated restorative materials in orthodontics, various methods have been suggested to enhance the polymerization of the materials used, including use of more powerful light curing devices. Bond strength is an important property and determines the amount of force delivered and the treatment duration. Many light-cured bonding materials have become popular but it is the need of the hour to determine the bonding agent that is the most efficient and has the desired bond strength. Aim: To evaluate and compare the shear bond strengths of five different orthodontic light cure bonding materials cured with traditional halogen light and low-intensity light-emitting diode (LED light curing unit. Materials and Methods: 100 human maxillary premolar teeth, extracted for orthodontic purpose, were used to prepare the samples. 100 maxillary stainless steel bicuspid brackets of 0.018 slot of Roth prescription, manufactured by D-tech Company, were bonded to the prepared tooth surfaces of the mounted samples using five different orthodontic bracket bonding light-cured materials, namely, Enlight, Fuji Ortho LC (resin-modified glass ionomer cement, Orthobond LC, Relybond, and Transbond XT. The bond strength was tested on an Instron Universal testing machine (model no. 5582. Results: In Group 1 (halogen group, Enlight showed the highest shear bond strength (16.4 MPa and Fuji Ortho LC showed the least bond strength (6.59 MPa (P value 0.000. In Group 2 (LED group, Transbond showed the highest mean shear bond strength (14.6 MPa and Orthobond LC showed the least mean shear bond strength (6.27 MPa (P value 0.000. There was no statistically significant difference in the shear bond strength values of all samples cured using either halogen (mean 11.49 MPa or LED (mean 11.20 MPa, as the P value was 0.713. Conclusion: Polymerization with both halogen and LED resulted in shear bond strength values which were above the

A Light-Weight Instrumentation System Design

International Nuclear Information System (INIS)

Kidner, Ronald

1999-01-01

To meet challenging constraints on telemetry system weight and volume, a custom Light-Weight Instrumentation System was developed to collect vehicle environment and dynamics on a short-duration exo-atmospheric flight test vehicle. The total telemetry system, including electronics, sensors, batteries, and a 1 watt transmitter weighs about 1 kg. Over 80 channels of measurement, housekeeping, and telemetry system diagnostic data are transmitted at 128 kbps. The microcontroller-based design uses the automotive industry standard Controller Area Network to interface with and support in-flight control fimctions. Operational parameters are downloaded via a standard asynchronous serial communications intefiace. The basic design philosophy and functionality is described here

Effect of light aging on silicone-resin bond strength in maxillofacial prostheses.

Science.gov (United States)

Polyzois, Gregory; Pantopoulos, Antonis; Papadopoulos, Triantafillos; Hatamleh, Muhanad

2015-04-01

The aim of this study was to investigate the effect of accelerated light aging on bond strength of a silicone elastomer to three types of denture resin. A total of 60 single lap joint specimens were fabricated with auto-, heat-, and photopolymerized (n = 20) resins. An addition-type silicone elastomer (Episil-E) was bonded to resins treated with the same primer (A330-G). Thirty specimens served as controls and were tested after 24 hours, and the remaining were aged under accelerated exposure to daylight for 546 hours (irradiance 765 W/m(2) ). Lap shear joint tests were performed to evaluate bond strength at 50 mm/min crosshead speed. Two-way ANOVA and Tukey's test were carried out to detect statistical significance (p Accelerated light aging for 546 hours affects the bond strength of an addition-type silicone elastomer to three different denture resins. The bond strength significantly increased after aging for photo- and autopolymerized resins. All the bonds failed adhesively. © 2014 by the American College of Prosthodontists.

A Comparison of the Shear Bond Strength of Orthodontic Brackets Bonded With Light-Emitting Diode and Halogen Light-Curing Units

Directory of Open Access Journals (Sweden)

SM. Abtahi

2006-09-01

Full Text Available Statement of the problem: Various methods such as light emitting diode (LED have been used to enhance the polymerization of resin-based orthodontic adhesives. There is a lack of information on the advantages and disadvantages of different light curing systems.Purpose: The aim of this study was to compare the effect of LED and halogen light curing systems on the shear bond strength of orthodontic brackets.Materials and Methods: Forty extracted human premolars were etched with 37% phosphoric acid and cleansed with water spray and air dried. The sealant was applied on the tooth surface and the brackets were bonded using Transbond adhesive (3M Unitek,Monrovia, Calif. Adhesives were cured for 40 and 20 seconds with halogen (Blue Light, APOZA, Taiwan and LED (Blue dent, Smart, Yugoslavia light-curing systems,respectively. Specimens were thermocycled 2500 times (from 5 to 55 °C and the shear bond strength of the adhesive system was evaluated with an Universal testing machine (Zwick GmbH, Ulm, Germany at a crosshead speed of 1 mm/min until the bracketswere detached from the tooth. Adhesive remnant index (ARI scores were determined after bracket failure. The data were submitted to statistical analysis, using Mann-Whitney analysis and t-test.Results: No significant difference was found in bond strength between the LED and halogen groups (P=0.12. A significant difference was not observed in the adhesive remnant index scores between the two groups (P=0.97.Conclusion: Within the limitations of this in vitro study, the shear bond strength of resin-based orthodontic adhesives cured with a LED was statistically equivalent to those cured with a conventional halogen-based unit. LED light-curing units can be suggested for the polymerization of orthodontic bonding adhesives.

Influence of refraction index strength on the light propagation in dielectrics material with periodic refraction index

International Nuclear Information System (INIS)

Hidayat, Arif; Latifah, Eny; Kurniati, Diana; Wisodo, Hari

2016-01-01

This study investigated the influence of refraction index strength on the light propagation in refraction index-varied dielectric material. This dielectric material served as photonic lattice. The behavior of light propagation influenced by variation of refraction index in photonic lattice was investigated. Modes of the guiding light were determined numerically using squared-operator iteration method. It was found that the greater the strength of refraction index, the smaller the guiding modes.

Development of low weight self-levelling mortars

International Nuclear Information System (INIS)

Padilla, A; Panama, I; Toledo, A; Flores, A

2015-01-01

This work shows the development of self levelling mortars, using micro bubbles based on aluminium silicate with a density of 0.25 g/cm 3 . Mortars formulations are composed by 8 different components in order to achieve properties balance between fresh and solid state. The mean objective is development light weight mortars with high fluidity and compression strength using micro bubbles and some additives. Formulations were designed employing Taguchi DOE of 8 variables and 3 states. Result analysis according to Taguchi method lets indentify the preponderant effect of each variable on the cited properties. Several formulations reached fluidity higher than 250%, with compression strength around 100 kg/cm 2 and a low volumetric weigh. Obtained volumetric weights are 20% less than commercial self levelling mortars weight. Finally some relations are presented such: as relation water/cement with fluidity, and micro bubble content versus mortars volumetric weight, and finally compression strength versus the volumetric weight of mortars

Thermal performance of heavy-weight and light-weight steel frame construction approaches in the central Pretoria climate

CSIR Research Space (South Africa)

Kumirai, T

2013-01-01

Full Text Available -1 Journal for New Generation Sciences Thermal performance of heavy-weight and light-weight steel frame construction approaches in the central Pretoria climate T Kumirai and DCU Conradie Built Environment, Council for Scientific and Industrial...

The contribution of prenatal environment and genetic factors to the association between birth weight and adult grip strength.

Directory of Open Access Journals (Sweden)

Charlotte L Ridgway

2011-03-01

Full Text Available Low birth weight has been associated with reduced hand grip strength, which is a marker of future physical function and disease risk. The aim of this study was to apply a twin pair approach, using both 'individual' data and 'within-pair' differences, to investigate the influence of birth weight on hand grip strength and whether this association may be mediated through fat free mass (FFM. Participants from the East Flanders Prospective Twin Survey were included if born without congenital abnormalities, birth weight >500 g and ≥22 weeks of gestation. Follow up in adulthood (age: 18-34 year, included anthropometric measures and hand grip (n = 783 individuals, n = 326 same-sex twin pairs. Birth weight was positively associated with hand grip strength (β = 2.60 kg, 95% CI 1.52, 3.67, p<0.001 and FFM (β = 4.2, 95% CI 3.16, 5.24, p<0.001, adjusted for gestational age, sex and adult age. Using 'within-pair' analyses, the birth weight hand grip association was significant in DZ men only (β = 5.82, 95% CI 0.67, 10.97, p = 0.028, which was attenuated following adjustment for FFM. Within-pair birth weight FFM associations were most pronounced in DZ men (β = 11.20, 95% CI 7.18, 15.22, p<0.001. Our 'individual' analyses show that higher birth weight is associated with greater adult hand grip strength, which is mediated through greater adult FFM. The 'within-pair' analyses confirm this observation and furthermore show that, particularly in men, genetic factors may in part explain this association, as birth weight differences in DZ men result in greater differences in adult strength and FFM.

Elastic Bands in Combination With Free Weights in Strength Training: Neuromuscular Effects.

Science.gov (United States)

Andersen, Vidar; Fimland, Marius S; Kolnes, Maria K; Saeterbakken, Atle H

2015-10-01

This study compared the effects of a variable vs. a constant lower limb resistance training program on muscle strength, muscle activation, and ballistic muscle performance at different knee angles. Thirty-two females were randomized to a constant resistance training free-weight group (FWG) or a variable resistance training group using free weights in combination with elastic bands (EBG). Two variations of the squat exercise (back squat and split) were performed 2 days per week for 10 weeks. Knee extensor maximal voluntary isometric contraction (MVC) and countermovement jump were assessed at knee angles of 60, 90, and 120° before and after the intervention. During the MVCs, muscle activation of the superficial knee extensor muscles was measured using surface electromyography. The FWG increased their MVCs at 60 and 90° (24 and 15%, respectively), whereas the EBG only increased significantly at 60° (15%). The FWG increased their jump height significantly at all angles (12-16%), whereas the EBG only improved significantly at 60 and 90° (15 and 10%, respectively). Both groups improved their 6-repetition maximum free-weight squat performance (EBG: 25% and FWG: 23%). There were no significant changes in muscle activation. In conclusion, constant and variable resistance training provided similar increases in dynamic and isometric strength, and ballistic muscle performance, albeit most consistently for the group training only with free weights.

Advanced high strength steels for automotive industry

Energy Technology Data Exchange (ETDEWEB)

Galan, J.; Samek, L.; Verleysen, P.; Verbeken, K.; Houbert, Y.

2012-11-01

The car industry is facing pressure because of the growing demand for more fuel-efficient passenger cars. In order to limit energy consumption and air pollution the weight of the car body has to be reduced. At the same time, high levels of safety have to be guaranteed. In this situation, the choice of material becomes a key decision in car design. As a response to the requirements of the automotive sector, high strength steels and advanced high strength steels have been developed by the steel industry. These modern steel grades offer an excellent balance of low cost, light weight and mechanical properties. (Author) 48 refs.

The Development of light-weight 2-link robot arm for high radiation area

Energy Technology Data Exchange (ETDEWEB)

Shin, Ho Cheol; Seo, Yong Chil; Jung, Kyung Min; Choi, Young Soo

2009-10-15

A light-weight 2-link robot arm which weight is less than 8kg was developed for treating the small radio-active material in the high radiation area such as nuclear power plants and NDT area. The light-weight 2-link robot arm can be attached on a small mobile robot and carry out tasks. It is a 5 DOF robot arm including a gripper

Comparison of Strength Gains in Untrained College-Age Females Using Free Weights and Freemotion Machines

Science.gov (United States)

Milton, Katherine; Wojcik, Janet R.; Boyd, Joni M.; Bowers, Charles J.

2018-01-01

Resistance training has become a preferred method for developing muscular strength among various populations. A variety of resistance training modes are available, but there are mixed outcomes regarding strength development among barbells, dumbbells, and weight machines. The purpose of this study was to investigate the differences in strength…

Knee extensor strength and body weight in adolescent men and the risk of knee osteoarthritis by middle age.

Science.gov (United States)

Turkiewicz, Aleksandra; Timpka, Simon; Thorlund, Jonas Bloch; Ageberg, Eva; Englund, Martin

2017-10-01

To assess the extent to which knee extensor strength and weight in adolescence are associated with knee osteoarthritis (OA) by middle age. We studied a cohort of 40 121 men who at age 18 years in 1969/1970 underwent mandatory conscription in Sweden. We retrieved data on isometric knee extensor strength, weight, height, smoking, alcohol consumption, parental education and adult occupation from Swedish registries. We identified participants diagnosed with knee OA or knee injury from 1987 to 2010 through the National Patient Register. We estimated the HR of knee OA using multivariable-adjusted Cox proportional regression model. To assess the influence of adult knee injury and occupation, we performed a formal mediation analysis. The mean (SD) knee extensor strength was 234 (47) Nm, the mean (SD) weight was 66 (9.3) kg. During 24 years (median) of follow-up starting at the age of 35 years, 2049 persons were diagnosed with knee OA. The adjusted HR (95% CI) of incident knee OA was 1.12 (1.06 to 1.18) for each SD of knee extensor strength and 1.18 (1.15 to 1.21) per 5 kg of body weight. Fifteen per cent of the increase in OA risk due to higher knee extensor strength could be attributed to knee injury and adult occupation. Higher knee extensor strength in adolescent men was associated with increased risk of knee OA by middle age, challenging the current tenet of low muscle strength being a risk factor for OA. We confirmed higher weight to be a strong risk factor for knee OA. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Effect of 8 weeks of free-weight and machine-based strength training on strength and power performance.

Science.gov (United States)

Wirth, Klaus; Keiner, Michael; Hartmann, Hagen; Sander, Andre; Mickel, Christoph

2016-12-01

The aim of this study was to evaluate the effectiveness of free-weight and machine-based exercises to increase different strength and speed-strength variables. One hundred twenty male participants (age: 23.8 ± 2.5 years; body height: 181.0 ± 6.8 cm; body mass: 80.2 ± 8.9 kg) joined the study. The 2 experimental groups completed an 8 week periodized strength training program that included 2 training sessions per week. The exercises that were used in the strength training programs were the parallel barbell squat and the leg press. Before and after the training period, the 1-repetition-maximum in the barbell squat and the leg press, the squat jump, the countermovement jump and unilateral isometric force (maximal isometric force and the rate of force development) were evaluated. To compare each group pre vs. post-intervention, analysis of variance with repeated measures and Scheffé post-hoc tests were used. The leg press group increased their 1-repetition-maximum significantly (p squat group such variables as 1-repetition-maximum, the squat jump and the countermovement jump increased significantly (p squat group even showed a statistically significant decrease. Differences between the 2 experimental groups were detected for the squat jump and the countermovement jump. In comparison with the leg press, the squat might be a better strength training exercise for the development of jump performance.

Thermal properties of light-weight concrete with waste polypropylene aggregate

Science.gov (United States)

Záleská, Martina; Pokorný, Jaroslav; Pavlíková, Milena; Pavlík, Zbyšek

2017-07-01

Thermal properties of a sustainable light-weight concrete incorporating high volume of waste polypropylene as partial substitution of natural aggregate were studied in the paper. Glass fiber reinforced polypropylene (GFPP), a by-product of PP tubes production, partially substituted fine natural silica aggregate in 10, 20, 30, 40, and 50 mass%. In order to quantify the effect of GFPP use on concrete properties, a reference concrete mix without plastic waste was studied as well. For the applied GFPP, bulk density, matrix density, and particle size distribution were measured. Specific attention was paid to thermal transport and storage properties of GFPP that were examined in dependence on compaction time. For the developed light-weight concrete, thermal properties were accessed using transient impulse technique, whereas the measurement was done in dependence on moisture content, from the dry state to fully water saturated state. Additionally, the investigated thermal properties were plotted as function of porosity. The tested light-weight concrete was found to be prospective construction material possessing improved thermal insulation function. Moreover, the reuse of waste plastics in concrete composition was beneficial both from the environmental and financial point of view considering plastics low biodegradability and safe disposal.

The effect of different light-curing units on tensile strength and microhardness of a composite resin

Directory of Open Access Journals (Sweden)

Eduardo Batista Franco

2007-12-01

Full Text Available The aim of this study was to evaluate the influence of different light-curing units on the tensile bond strength and microhardness of a composite resin (Filtek Z250 - 3M/ESPE. Conventional halogen (Curing Light 2500 - 3M/ESPE; CL and two blue light emitting diode curing units (Ultraled - Dabi/Atlante; UL; Ultrablue IS - DMC; UB3 and UB6 were selected for this study. Different light intensities (670, 130, 300, and 600 mW/cm², respectively and different curing times (20s, 40s and 60s were evaluated. Knoop microhardness test was performed in the area corresponding to the fractured region of the specimen. A total of 12 groups (n=10 were established and the specimens were prepared using a stainless steel mold composed by two similar parts that contained a cone-shaped hole with two diameters (8.0 mm and 5.0 mm and thickness of 1.0 mm. Next, the specimens were loaded in tensile strength until fracture in a universal testing machine at a crosshead speed of 0.5 mm/min and a 50 kg load cell. For the microhardness test, the same matrix was used to fabricate the specimens (12 groups; n=5. Microhardness was determined on the surfaces that were not exposed to the light source, using a Shimadzu HMV-2 Microhardness Tester at a static load of 50 g for 30 seconds. Data were analyzed statistically by two-way ANOVA and Tukey's test (p<0.05. Regarding the individual performance of the light-curing units, there was similarity in tensile strength with 20-s and 40-s exposure times and higher tensile strength when a 60-s light-activation time was used. Regarding microhardness, the halogen lamp had higher results when compared to the LED units. For all light-curing units, the variation of light-exposure time did not affect composite microhardness. However, lower irradiances needed longer light-activation times to produce similar effect as that obtained with high-irradiance light-curing sources.

data sets Simulations in articulating light-weight PRS

NARCIS (Netherlands)

Van den Berg, Bert

2008-01-01

The data sets are output of 3 different steps in the development a simulations of a PRS as described in chapter 3.3: Simulations in articulating light-weight PRS A case for Pedagogy-oriented and Rating-based Hybrid Recommendation Strategies Rob Nadolski, Bert van den Berg, Adriana Berlanga, Hans

Knee extensor strength and body weight in adolescent men and the risk of knee osteoarthritis by middle age

DEFF Research Database (Denmark)

Turkiewicz, Aleksandra; Timpka, Simon; Thorlund, Jonas Bloch

2017-01-01

be attributed to knee injury and adult occupation. CONCLUSION: Higher knee extensor strength in adolescent men was associated with increased risk of knee OA by middle age, challenging the current tenet of low muscle strength being a risk factor for OA. We confirmed higher weight to be a strong risk factor......OBJECTIVES: To assess the extent to which knee extensor strength and weight in adolescence are associated with knee osteoarthritis (OA) by middle age. METHODS: We studied a cohort of 40 121 men who at age 18 years in 1969/1970 underwent mandatory conscription in Sweden. We retrieved data...

Weighted oscillator strengths and lifetimes for the S VII spectrum

International Nuclear Information System (INIS)

Borges, F.O.; Cavalcanti, G.H.; Trigueiros, A.G.; Jupen, C.

2004-01-01

The weighted oscillator strengths (gf) and the lifetimes presented in this work were carried out in a multiconfiguration Hartree-Fock relativistic approach. In this calculation, the electrostatic parameters were optimized by a least-squares procedure, in order to improve the adjustment to experimental energy levels. This method produces gf-values that are in better agreement with intensity observations and lifetime values that are closer to the experimental ones. In this work, we presented all the experimentally known electric dipole S VII spectral lines

Acute short-term dim light exposure can lower muscle strength endurance

OpenAIRE

Arnold G. Nelson; Joke Kokkonen; Megan Mickenberg

2015-01-01

Background: Since it has been shown that spending 18 h under dim light conditions can result in reduced handgrip endurance, it was questioned whether or not a shorter exposure to dim light (i.e., 1 h) would have similar influence upon muscular endurance. Therefore this study compared the number of weighted knee extension lifts that could be done after spending 1 h in either dim or bright light. Methods: Participants (5 women, 11 men, college students 19–26 years) performed knee extension l...

Light-weight analyzer for odor recognition

Energy Technology Data Exchange (ETDEWEB)

Vass, Arpad A; Wise, Marcus B

2014-05-20

The invention provides a light weight analyzer, e.g., detector, capable of locating clandestine graves. The detector utilizes the very specific and unique chemicals identified in the database of human decompositional odor. This detector, based on specific chemical compounds found relevant to human decomposition, is the next step forward in clandestine grave detection and will take the guess-work out of current methods using canines and ground-penetrating radar, which have historically been unreliable. The detector is self contained, portable and built for field use. Both visual and auditory cues are provided to the operator.

The effects of combined elastic- and free-weight tension vs. free-weight tension on one-repetition maximum strength in the bench press.

Science.gov (United States)

Bellar, David M; Muller, Matthew D; Barkley, Jacob E; Kim, Chul-Ho; Ida, Keisuke; Ryan, Edward J; Bliss, Mathew V; Glickman, Ellen L

2011-02-01

The present study investigated the effects of training combining elastic tension, free weights, and the bench press. Eleven college-aged men (untrained) in the bench press participated in the 13-week study. The participants were first given instructions and then practiced the bench press, followed by a one-repetition maximum (1RM) test of baseline strength. Subjects were then trained in the bench press for 3 weeks to allow for the beginning of neural adaptation. After another 1RM test, participants were assigned to 1 of 2 conditions for the next 3 weeks of training: 85% Free-Weight Tension, 15% Elastic Tension (BAND), or 100% Free-Weight Tension (STAND). After 3 weeks of training and a third 1RM max test, participants switched treatments, under which they completed the final 3 weeks of training and the fourth 1RM test. Analysis via analysis of covariance revealed a significant (p ≤ 0.05) main effect for time and interaction effect for Treatment (BAND vs. STAND). Subsequent analysis via paired-samples t-test revealed the BAND condition was significantly better (p = 0.05) at producing raw gains in 1RM strength. (BAND 9.95 ± 3.7 kg vs. STAND 7.56 ± 2.8 kg). These results suggest that the addition of elastic tension to the bench press may be an effective method of increasing strength.

Influence of adhesion promoters and curing-light sources on the shear bond strength of orthodontic brackets

Directory of Open Access Journals (Sweden)

Claudia Tavares Machado

2012-01-01

Conclusions: The conventional orthodontic adhesive presented higher bond strength than the nanofilled composite, although both materials interacted similarly to the teeth. The curing-light devices tested did not influence on bond strength of orthodontic brackets.

Evaluation of Impact Strength of Epoxy Based Hybrid Composites Reinforced with E-Glass/Kevlar 49

OpenAIRE

Jogi , Subhan Ali; Moazam Baloch , Muhammad; Chandio , Ali ,; Memon , Iftikhar Ahmed; Chandio , Ghulaqm Sarwar

2017-01-01

International audience; In hybridization different fibers are stacked layer by layer to produce laminates have specific strength and stiffness and employed in light weight high strength applications. Physically mean fabricated hybrid composites used in aerospace, under water, body armors and armed forces establishment. In present work drop-weight impact response of hybrid composites were investigated by making laminates of hybrid composites. In Hybridization layers of E-glass (roving) and Kev...

A New Light Weight Structural Material for Nuclear Structures

Energy Technology Data Exchange (ETDEWEB)

Rabiei, Afsaneh [North Carolina State Univ., Raleigh, NC (United States)

2016-01-14

Radiation shielding materials are commonly used in nuclear facilities to attenuate the background ionization radiations to a minimum level for creating a safer workplace, meeting regulatory requirements and maintaining high quality performance. The conventional radiation shielding materials have a number of drawbacks: heavy concrete contains a high amount of elements that are not desirable for an effective shielding such as oxygen, silicon, and calcium; a well known limitation of lead is its low machinability and toxicity, which is causing a major environmental concern. Therefore, an effective and environmentally friendly shielding material with increased attenuation and low mass density is desirable. Close-cell composite metal foams (CMFs) and open-cell Al foam with fillers are light-weight candidate materials that we have studied in this project. Close-cell CMFs possess several suitable properties that are unattainable by conventional radiation shielding materials such as low density and high strength for structural applications, high surface area to volume ratio for excellent thermal isolation with an extraordinary energy absorption capability. Open-cell foam is made up of a network of interconnected solid struts, which allows gas or fluid media to pass through it. This unique structure provided a further motive to investigate its application as radiation shields by infiltrating original empty pores with high hydrogen or boron compounds, which are well known for their excellent neutron shielding capability. The resulting open-cell foam with fillers will not only exhibit light weight and high specific surface area, but also possess excellent radiation shielding capability and good processability. In this study, all the foams were investigated for their radiation shielding efficiency in terms of X-ray, gamma ray and neutron. X-ray transmission measurements were carried out on a high-resolution microcomputed tomography (microCT) system. Gamma-emitting sources: 3.0m

A New Light Weight Structural Material for Nuclear Structures

International Nuclear Information System (INIS)

Rabiei, Afsaneh

2016-01-01

Radiation shielding materials are commonly used in nuclear facilities to attenuate the background ionization radiations to a minimum level for creating a safer workplace, meeting regulatory requirements and maintaining high quality performance. The conventional radiation shielding materials have a number of drawbacks: heavy concrete contains a high amount of elements that are not desirable for an effective shielding such as oxygen, silicon, and calcium; a well known limitation of lead is its low machinability and toxicity, which is causing a major environmental concern. Therefore, an effective and environmentally friendly shielding material with increased attenuation and low mass density is desirable. Close-cell composite metal foams (CMFs) and open-cell Al foam with fillers are light-weight candidate materials that we have studied in this project. Close-cell CMFs possess several suitable properties that are unattainable by conventional radiation shielding materials such as low density and high strength for structural applications, high surface area to volume ratio for excellent thermal isolation with an extraordinary energy absorption capability. Open-cell foam is made up of a network of interconnected solid struts, which allows gas or fluid media to pass through it. This unique structure provided a further motive to investigate its application as radiation shields by infiltrating original empty pores with high hydrogen or boron compounds, which are well known for their excellent neutron shielding capability. The resulting open-cell foam with fillers will not only exhibit light weight and high specific surface area, but also possess excellent radiation shielding capability and good processability. In this study, all the foams were investigated for their radiation shielding efficiency in terms of X-ray, gamma ray and neutron. X-ray transmission measurements were carried out on a high-resolution microcomputed tomography (microCT) system. Gamma-emitting sources: 3.0m

The Effects of Rapid Weight Loss and Attempted Rehydration on Strength and Endurance of the Handgripping Muscles in College Wrestlers.

Science.gov (United States)

Serfass, Robert C.; And Others

1984-01-01

Because of the continued prevalence of rapid weight reduction by wrestlers, this study attempted to determine if college wrestlers' strength and muscular endurance were affected by either rehydration or dehydration. Results showed that a loss of five percent of body weight over three days did not affect strength or endurance levels. (JMK)

Effect of 8 weeks of free-weight and machine-based strength training on strength and power performance

Directory of Open Access Journals (Sweden)

Wirth Klaus

2016-12-01

Full Text Available The aim of this study was to evaluate the effectiveness of free-weight and machine-based exercises to increase different strength and speed-strength variables. One hundred twenty male participants (age: 23.8 ± 2.5 years; body height: 181.0 ± 6.8 cm; body mass: 80.2 ± 8.9 kg joined the study. The 2 experimental groups completed an 8 week periodized strength training program that included 2 training sessions per week. The exercises that were used in the strength training programs were the parallel barbell squat and the leg press. Before and after the training period, the 1-repetition-maximum in the barbell squat and the leg press, the squat jump, the countermovement jump and unilateral isometric force (maximal isometric force and the rate of force development were evaluated. To compare each group pre vs. post-intervention, analysis of variance with repeated measures and Scheffé post-hoc tests were used. The leg press group increased their 1-repetition-maximum significantly (p < 0.001, while in the squat group such variables as 1-repetition-maximum, the squat jump and the countermovement jump increased significantly (p < 0.001. The maximal isometric force showed no statistically significant result for the repeated measures factor, while the rate of force development of the squat group even showed a statistically significant decrease. Differences between the 2 experimental groups were detected for the squat jump and the countermovement jump. In comparison with the leg press, the squat might be a better strength training exercise for the development of jump performance.

Strength characteristics of lightly solidified dredged marine clay admixed with bentonite

Science.gov (United States)

Ariffin, Syazwana Tajul; Chan, Chee-Ming

2017-11-01

Strength characteristic is a significant parameter in measuring the effect of soil improvement and effective composition of solidification. In this study, the dredged marine sediment (DMS) collected from Kuala Perlis (Malaysia) was examined to determine its strength characteristics under light cement solidification with bentonite. Dredged marine clay generally has the low shear strength and high void ratio, and consists mainly of soil particles of the fine-grained type. As a discarded geo-waste, it can be potentially treated to for reuse as a backfill material instead of being disposed of, hence reducing the negative impact on the environment. Physico-chemical parameters of the dredged sample were first determined, then solidification was carried out to improve the engineering properties by admixing ordinary Portland cement (OPC) as the binder and bentonite as a volume enhancer to the soil. The DMS was treated with the addition of 3 % and 6 % cement and bentonite within the range of 0-30 %. The specimens were cured at room temperature for 3, 7 and 14 days. The strength gain was measured by unconfined compression test and vane shear test. The laboratory test results were analyzed to establish the relationship between strength properties and solidification specifications. In summary, the strength of specimens increased with the increase of the quantity of bentonite and cement to get the effective composition of the specimen.

Level densities and γ strength functions in light Sc and Ti isotopes

International Nuclear Information System (INIS)

Burger, A.; Larsen, A.C.; Syed, N.U.H.; Guttormsen, M.; Nyhus, H.; Siem, S.; Harissopulos, S.; Konstantinopoulos, T.; Lagoyannis, A.; Perdidakis, G.; Spyrou, A.; Kmiecik, M.; Mazurek, K.; Krticka, M.; Loennroth, T.; Norby, M.; Voinov, A.

2010-01-01

We present preliminary results from a measurement of nuclear level densities and the γ-ray strength of light Sc (Sc 43 , Sc 45 ) and Ti (Ti 44 , Ti 45 and Ti 46 ) isotopes using the Oslo Method. The article begins with a presentation of the experimental setup. (authors)

Comparison of shear bond strength of stainless steel brackets bonded with three light- cured adhesives

Directory of Open Access Journals (Sweden)

Zahra Minaei Basharik

2015-09-01

Full Text Available Introduction: The bonding process of the brackets to enamel has been a critical issue in orthodontic research. The purpose of this study was to evaluate the shear bond strength of 3 light-cured adhesives (transbond XT, Z250, light bond. Materials &Methods: In this study sixty extracted human premolars were collected and randomly divided into 3 test groups. All teeth were etched by 37% phosphoric acid. In first group brackets were bonded by Transbond XT adhesive, in group two brackets were bonded by Light bond adhesive and in third group were bonded by filtek Z250 composite. All of them were cured with Ortholux xt for 40 seconds.24 hours after thermocycling, Shear Bond Strength (SBS values of these brackets were recorded using a Universal Testing Machine. Adhesive Remnant Index (ARI scores were determined after the failure of the brackets, using Stereo Microscope the data were analyzed using ANOVA and Chi-square tests. Results: Mean shear bond strength of Transbond XT, light bond and Z250 were 28.9±2.25 MPa, 25.06±1.98 MPa and 26.8±2.57 MPa, respectively. No significant difference was observed in the SBS among the groups and a clinically acceptable SBS was found for the three adhesives. ARI scores were not significantly different between the various groups (P>0.05. Conclusion: This study showed that the Z250 can be used as light bond and transbond xt to bond orthodontic brackets and ARI and SBS scores were not significantly different.

A low cost, light weight cenosphere–aluminium composite for brake ...

Indian Academy of Sciences (India)

. Home; Journals; Bulletin of Materials Science; Volume 39; Issue 1. A low cost, light weight cenosphere–aluminium composite for brake disc application. V Saravanan P R Thyla S R Balakrishnan. Volume 39 Issue 1 February 2016 pp 299-305 ...

Light-weight extension tubes for compressed-air garden sprayers

Science.gov (United States)

Thomas W. McConkey; Charles E. Swett

1967-01-01

To hand-spray taller trees safely and efficiently, 8-, 12-, and 16-foot extension tubes for compressed-air garden sprayers were designed and built. These light-weight tubes have been used successfully for spraying white pine leaders for weevil control on the Massabesic Experimental Forest in Maine. Bill of materials and assembly instructions are included.

Light-weight Mutual Authentication with Non-repudiation

Directory of Open Access Journals (Sweden)

V. Clupek

2018-04-01

Full Text Available In this paper, we focused on a problem of authentication on low-cost devices. We have proposed a new light-weight protocol for mutual authentication of communication entities with non-repudiation of realized events. The protocol is simple and suitable for implementation on low-cost devices. Non-repudiation of realized events is achieved by involving a Trusted Third Party (TTP to the communication. The proposed protocol uses only an appropriate lightweight hash function and pre-shared secret data. Security of the proposed protocol was verified by the BAN (Burrows-Abadi-Needham logic.

Acute Effects of the Elevation Training Mask on Strength Performance in Recreational Weight lifters.

Science.gov (United States)

Jagim, Andrew R; Dominy, Trevor A; Camic, Clayton L; Wright, Glenn; Doberstein, Scott; Jones, Margaret T; Oliver, Jonathan M

2018-02-01

Jagim, AR, Dominy, TA, Camic, CL, Wright, G, Doberstein, S, Jones, MT, and Oliver, JM. Acute effects of the elevation training mask on strength performance in recreational weightlifters. J Strength Cond Res 32(2): 482-489, 2018-The Elevation Training Mask 2.0 (ETM) is a novel device that purportedly simulates altitude training. The purpose of this study was to investigate the acute effects of the ETM on resistance exercise performance, metabolic stress markers, and ratings of mental fatigue. Twenty male recreational weight lifters completed 2 training sessions of back squat and bench press (6 sets of 10 repetitions at 85% of 5-repetition maximum and seventh set to failure) as well as a maximal effort sprint test (18% body mass) with the mask (ETM) and without the mask (NM). Training evaluation included baseline and postexercise blood lactate and oxygen saturation measures. Performance evaluation included peak and average velocity bar velocity, total volume load, total work, total repetitions completed, and sprint performance. Adverse side effects were reported in 12% (n = 3) of participants, which included feelings of light headedness, anxiety, and discomfort. No differences were found in repetitions or total workload in back squat (p = 0.07) or bench press (p = 0.08) between conditions. A lower peak velocity was identified during the back squat, bench press, and sprint test in the ETM condition (p = 0.04). Blood lactate values were lower after bench press and sprint during the ETM condition (p bench press, and sprint test in the ETM condition compared with the NM condition (p velocity during training bouts and negatively influence ratings of alertness and focus for task.

Influence of increment thickness on dentin bond strength and light transmission of composite base materials.

Science.gov (United States)

Omran, Tarek A; Garoushi, Sufyan; Abdulmajeed, Aous A; Lassila, Lippo V; Vallittu, Pekka K

2017-06-01

Bulk-fill resin composites (BFCs) are gaining popularity in restorative dentistry due to the reduced chair time and ease of application. This study aimed to evaluate the influence of increment thickness on dentin bond strength and light transmission of different BFCs and a new discontinuous fiber-reinforced composite. One hundred eighty extracted sound human molars were prepared for a shear bond strength (SBS) test. The teeth were divided into four groups (n = 45) according to the resin composite used: regular particulate filler resin composite: (1) G-ænial Anterior [GA] (control); bulk-fill resin composites: (2) Tetric EvoCeram Bulk Fill [TEBF] and (3) SDR; and discontinuous fiber-reinforced composite: (4) everX Posterior [EXP]. Each group was subdivided according to increment thickness (2, 4, and 6 mm). The irradiance power through the material of all groups/subgroups was quantified (MARC® Resin Calibrator; BlueLight Analytics Inc.). Data were analyzed using two-way ANOVA followed by Tukey's post hoc test. SBS and light irradiance decreased as the increment's height increased (p composite used. EXP presented the highest SBS in 2- and 4-mm-thick increments when compared to other composites, although the differences were not statistically significant (p > 0.05). Light irradiance mean values arranged in descending order were (p composites. Discontinuous fiber-reinforced composite showed the highest value of curing light transmission, which was also seen in improved bonding strength to the underlying dentin surface. Discontinuous fiber-reinforced composite can be applied safely in bulks of 4-mm increments same as other bulk-fill composites, although, in 2-mm thickness, the investigated composites showed better performance.

Acute effects of various weighted bat warm-up protocols on bat velocity.

Science.gov (United States)

Reyes, G Francis; Dolny, Dennis

2009-10-01

Although research has provided evidence of increased muscular performance following a facilitation set of resistance exercise, this has not been established for use prior to measuring baseball bat velocity. The purpose of this study was to determine the effectiveness of selected weighted bat warm-up protocols to enhance bat velocity in collegiate baseball players. Nineteen collegiate baseball players (age = 20.15 +/- 1.46 years) were tested for upper-body strength by a 3-repetition maximum (RM) bench press (mean = 97.98 +/- 14.54 kg) and mean bat velocity. Nine weighted bat warm-up protocols, utilizing 3 weighted bats (light = 794 g; standard = 850 g; heavy = 1,531 g) were swung in 3 sets of 6 repetitions in different orders. A control trial involved the warm-up protocol utilizing only the standard bat. Pearson product correlation revealed a significant relationship between 3RM strength and pretest bat velocity (r = 0.51, p = 0.01). Repeated measures analysis of variance (ANOVA) revealed no significant treatment effects of warm-up protocol on bat velocity. However, the order of standard, light, heavy bat sequence resulted in the greatest increase in bat velocity (+6.03%). These results suggest that upper-body muscle strength influences bat velocity. It appears that the standard, light, heavy warm-up order may provide the greatest benefit to increase subsequent bat velocity and may warrant use in game situations.

Moderate Versus Light Pressure Massage Therapy Leads to Greater Weight Gain in Preterm Infants

Science.gov (United States)

Field, Tiffany; Diego, Miguel A.; Hernandez-Reif, Maria; Deeds, Osvelia; Figuereido, Barbara

2007-01-01

Sixty-eight preterm infants (M GA=3Owks.) were randomly assigned to a moderate or to a light pressure massage therapy group to receive 15 massages 3 times per day for 5 days. Behavior state, stress behaviors and heart rate were recorded for 15 minutes before and during the first 15-minute therapy session. Weight gain was recorded over the 5 day therapy period. The moderate versus light pressure massage group gained significantly more weight per day. During the behavior observations the moderate versus light pressure massage group showed significantly lower increases from the pre-session to the session recording on: 1) active sleep; 2) fussing; 3) crying; 4) movement; and 5) stress behavior (hiccupping). They also showed a smaller decrease in deep sleep, a greater decrease in heart rate and a greater increase in vagal tone. Thus, the moderate pressure massage therapy group appeared to be more relaxed and less aroused than the light pressure massage group which may have contributed to the greater weight gain of the moderate pressure massage therapy group. PMID:17138310

Protein timing and its effects on muscular hypertrophy and strength in individuals engaged in weight-training

Directory of Open Access Journals (Sweden)

Stark Matthew

2012-12-01

Full Text Available Abstract The purpose of this review was to determine whether past research provides conclusive evidence about the effects of type and timing of ingestion of specific sources of protein by those engaged in resistance weight training. Two essential, nutrition-related, tenets need to be followed by weightlifters to maximize muscle hypertrophy: the consumption of 1.2-2.0 g protein.kg -1 of body weight, and ≥44-50 kcal.kg-1 of body weight. Researchers have tested the effects of timing of protein supplement ingestion on various physical changes in weightlifters. In general, protein supplementation pre- and post-workout increases physical performance, training session recovery, lean body mass, muscle hypertrophy, and strength. Specific gains, differ however based on protein type and amounts. Studies on timing of consumption of milk have indicated that fat-free milk post-workout was effective in promoting increases in lean body mass, strength, muscle hypertrophy and decreases in body fat. The leucine content of a protein source has an impact on protein synthesis, and affects muscle hypertrophy. Consumption of 3–4 g of leucine is needed to promote maximum protein synthesis. An ideal supplement following resistance exercise should contain whey protein that provides at least 3 g of leucine per serving. A combination of a fast-acting carbohydrate source such as maltodextrin or glucose should be consumed with the protein source, as leucine cannot modulate protein synthesis as effectively without the presence of insulin. Such a supplement post-workout would be most effective in increasing muscle protein synthesis, resulting in greater muscle hypertrophy and strength. In contrast, the consumption of essential amino acids and dextrose appears to be most effective at evoking protein synthesis prior to rather than following resistance exercise. To further enhance muscle hypertrophy and strength, a resistance weight- training program of at least 10–12 weeks

Protein timing and its effects on muscular hypertrophy and strength in individuals engaged in weight-training

Science.gov (United States)

2012-01-01

The purpose of this review was to determine whether past research provides conclusive evidence about the effects of type and timing of ingestion of specific sources of protein by those engaged in resistance weight training. Two essential, nutrition-related, tenets need to be followed by weightlifters to maximize muscle hypertrophy: the consumption of 1.2-2.0 g protein.kg -1 of body weight, and ≥44-50 kcal.kg-1 of body weight. Researchers have tested the effects of timing of protein supplement ingestion on various physical changes in weightlifters. In general, protein supplementation pre- and post-workout increases physical performance, training session recovery, lean body mass, muscle hypertrophy, and strength. Specific gains, differ however based on protein type and amounts. Studies on timing of consumption of milk have indicated that fat-free milk post-workout was effective in promoting increases in lean body mass, strength, muscle hypertrophy and decreases in body fat. The leucine content of a protein source has an impact on protein synthesis, and affects muscle hypertrophy. Consumption of 3–4 g of leucine is needed to promote maximum protein synthesis. An ideal supplement following resistance exercise should contain whey protein that provides at least 3 g of leucine per serving. A combination of a fast-acting carbohydrate source such as maltodextrin or glucose should be consumed with the protein source, as leucine cannot modulate protein synthesis as effectively without the presence of insulin. Such a supplement post-workout would be most effective in increasing muscle protein synthesis, resulting in greater muscle hypertrophy and strength. In contrast, the consumption of essential amino acids and dextrose appears to be most effective at evoking protein synthesis prior to rather than following resistance exercise. To further enhance muscle hypertrophy and strength, a resistance weight- training program of at least 10–12 weeks with compound movements for

Comprehensive Evaluation of Car-Body Light-Weighting Scheme Based on LCC Theory

Directory of Open Access Journals (Sweden)

Han Qing-lan

2016-01-01

Full Text Available In this paper, a comprehensive evaluation model of light-weighting scheme is established, which is based on three dimensions, including the life cycle costs of the resource consumed by the designed objects (LCC, willingness to pay for the environmental effect of resource consumption (WTP and performance (P. Firstly, cost of each stage is determined. Then, based on the resource classification, which is based on cost elements, determine the material list needed, and apply WTP weight coefficient to monetize life cycle environmental impact and obtain the life cycle comprehensive cost of designed scheme (TCC. In the next step Performance (P index is calculated to measure the value of the life cycle costs by applying AHP and SAW method, integrated (TCC and (P to achieve comprehensive evaluation of light-weighting scheme. Finally, the effectiveness of the evaluation model is verified by the example of car engine hood.

A light-weight hyperspectral mapping system for unmanned aerial vehicles - The first results

NARCIS (Netherlands)

Suomalainen, Juha; Anders, Niels; Iqbal, Shahzad; Franke, Jappe; Wenting, Philip; Bartholomeus, Harm; Becker, Rolf; Kooistra, Lammert

2017-01-01

Research opportunities using UAV remote sensing techniques are limited by the payload of the platform. Therefore small UAV's are typically not suitable for hyperspectral imaging due to the weight of the mapping system. In this research, we are developing a light-weight hyperspectral mapping system

Integrated Design Optimization of a 5-DOF Assistive Light-weight Anthropomorphic Arm

DEFF Research Database (Denmark)

Zhou, Lelai; Bai, Shaoping; Hansen, Michael Rygaard

2011-01-01

An integrated dimensional and drive train optimization method was developed for light-weight robotic arm design. The method deals with the determination of optimal link lengths and the optimal selection of motors and gearboxes from commercially available components. Constraints are formulated...... on the basis of kinematic performance and dynamic requirements, whereas the main objective is to minimize the weight. The design of a human-like arm, which is 10 kg in weight with a load capacity of 5 kg, is described....

Ultra light weight jet engine JR100; Chokeiryo jet engine JR100

Energy Technology Data Exchange (ETDEWEB)

Matsuki, M. [Nippon Institute of Technology, Saitama (Japan)

1999-03-20

As a part of the jet lift V/STOL research by National Aerospace Laboratory, a study of trial manufacture of ultra light weight jet engine JR 100 started in FY 1964. The study was aimed at obtaining a lift engine for VTOL and founding the base for the future jet lift VTOL, and at taking in the results of the jet engine element study accumulated so far and manufacturing an advanced engine. Decided on the use of domestic materials for JR 100, the materials to be used are almost iron-based ones. Through the efforts for weight reduction in structure and processing, a thrust/weight ratio of 10 was realized. At the same time, the production/processing of light weight materials such as titanium alloys was proceeded with, and by adopting the materials to JR 200 system, a thrust/weight ratio of 15 was realized. Together with these, for the purpose of reducing the fuel consumption rate, studies started on fan for lift fan engine and high temperature turbine (an inlet temperature of 1250 degrees C was achieved), to get low noise/high efficiency fan. By the research results, the basis for jet lift VTOL was established, and it became the basis for the development of turbo fan engine FJR 710. (NEDO)

Splitting of ISGMR strength in the light-mass nucleus 24Mg due to ground-state deformation

Directory of Open Access Journals (Sweden)

Y.K. Gupta

2015-09-01

Full Text Available The isoscalar giant monopole resonance (ISGMR strength distribution in 24Mg has been determined from background-free inelastic scattering of 386-MeV α particles at extreme forward angles, including 0∘. The ISGMR strength distribution has been observed for the first time to have a two-peak structure in a light-mass nucleus. This splitting of ISGMR strength is explained well by microscopic theory in terms of the prolate deformation of the ground state of 24Mg.

Light-weight spherical mirrors for Cherenkov detectors

CERN Document Server

Cisbani, E; Colilli, S; Crateri, R; Cusanno, F; De Leo, R; Fratoni, R; Frullani, S; Garibaldi, F; Giuliani, F; Gricia, M; Iodice, M; Iommi, R; Lagamba, L; Lucentini, M; Mostarda, A; Nappi, E; Pierangeli, L; Santavenere, F; Urciuoli, G M; Vernin, P

2003-01-01

Light-weight spherical mirrors have been appositely designed and built for the gas threshold Cherenkov detectors of the two Hall A spectrometers. The mirrors are made of a 1 mm thick aluminized plexiglass sheet, reinforced by a rigid backing consisting of a phenolic honeycomb sandwiched between two carbon fiber mats epoxy glued. The produced mirrors have a thickness equivalent to 0.55% of radiation length, and an optical slope error of about 5.5 mrad. These characteristics make these mirrors suitable for the implementation in Cherenkov threshold detectors. Ways to improve the mirror features are also discussed in view of their possible employment in RICH detectors.

High Folic Acid Intake during Pregnancy Lowers Body Weight and Reduces Femoral Area and Strength in Female Rat Offspring

Directory of Open Access Journals (Sweden)

Pedro S. P. Huot

2013-01-01

Full Text Available Rats fed gestational diets high in multivitamin or folate produce offspring of altered phenotypes. We hypothesized that female rat offspring born to dams fed a gestational diet high in folic acid (HFol have compromised bone health and that feeding the offspring the same HFol diet attenuates these effects. Pregnant rats were fed diets with either recommended folic acid (RFol or 10-fold higher folic acid (HFol amounts. Female offspring were weaned to either the RFol or HFol diet for 17 weeks. HFol maternal diet resulted in lower offspring body weights (6%, P=0.03 and, after adjusting for body weight and femoral length, smaller femoral area (2%, P=0.03, compared to control diet. After adjustments, HFol pup diet resulted in lower mineral content (7%, P=0.01 and density (4%, P=0.002 of lumbar vertebra 4 without differences in strength. An interaction between folate content of the dam and pup diets revealed that a mismatch resulted in lower femoral peak load strength (P=0.01 and stiffness (P=0.002. However, the match in folate content failed to prevent lower weight gain. In conclusion, HFol diets fed to rat dams and their offspring affect area and strength of femurs and mineral quantity but not strength of lumbar vertebrae in the offspring.

Light-weight reference-based compression of FASTQ data.

Science.gov (United States)

Zhang, Yongpeng; Li, Linsen; Yang, Yanli; Yang, Xiao; He, Shan; Zhu, Zexuan

2015-06-09

The exponential growth of next generation sequencing (NGS) data has posed big challenges to data storage, management and archive. Data compression is one of the effective solutions, where reference-based compression strategies can typically achieve superior compression ratios compared to the ones not relying on any reference. This paper presents a lossless light-weight reference-based compression algorithm namely LW-FQZip to compress FASTQ data. The three components of any given input, i.e., metadata, short reads and quality score strings, are first parsed into three data streams in which the redundancy information are identified and eliminated independently. Particularly, well-designed incremental and run-length-limited encoding schemes are utilized to compress the metadata and quality score streams, respectively. To handle the short reads, LW-FQZip uses a novel light-weight mapping model to fast map them against external reference sequence(s) and produce concise alignment results for storage. The three processed data streams are then packed together with some general purpose compression algorithms like LZMA. LW-FQZip was evaluated on eight real-world NGS data sets and achieved compression ratios in the range of 0.111-0.201. This is comparable or superior to other state-of-the-art lossless NGS data compression algorithms. LW-FQZip is a program that enables efficient lossless FASTQ data compression. It contributes to the state of art applications for NGS data storage and transmission. LW-FQZip is freely available online at: http://csse.szu.edu.cn/staff/zhuzx/LWFQZip.

Laser beam welding of new ultra-high strength and supra-ductile steels

OpenAIRE

Dahmen, M.

2015-01-01

Ultra-high strength and supra-ductile are entering fields of new applications. Those materials are excellent candidates for modern light-weight construction and functional integration. As ultra-high strength steels the stainless martensitic grade 1.4034 and the bainitic steel UNS 53835 are investigated. For the supra-ductile steels stand two high austenitic steels with 18 and 28 % manganese. As there are no processing windows an approach from the metallurgical base on is required. Adjusting t...

General and smoking cessation weight concern in a Hispanic sample of light and intermittent smokers.

Science.gov (United States)

Landrau-Cribbs, Erica; Cabriales, José Alonso; Cooper, Theodore V

2015-02-01

This study assessed general and cessation related weight concerns in a Hispanic sample of light (≤10 cigarettes per day) and intermittent (non-daily smoking) smokers (LITS) participating in a brief smoking cessation intervention. Three hundred and fifty-four Hispanic LITS (Mage=34.2, SD=14; 51.1% male; 57.9% Mexican American; 59.0% daily light, 41.0% intermittent) completed baseline measures assessing demographics, tobacco use/history, stage of change (SOC), general weight concern, and cessation related weight concern. Three multiple logistic regression models examined potential predictors (i.e., age, gender, SOC, cigarettes per month, smoking status [daily vs non-daily], weight, cessation related weight concern, general weight concern) of general weight concern, cessation related weight concern, and past 30day abstinence (controlling for the intervention). Study results indicated that a majority of participants reported general weight concern (59.6%), and slightly more than a third (35.6%) reported post cessation weight gain concern (mean and median weight tolerated before relapse were within the 10-12lb range). Lower weight and endorsing general weight concern were associated with cessation related weight concern. Female gender, higher weight, and endorsing cessation related weight concern were associated with general weight concern. Monthly cigarette use was associated with smoking cessation at the three-month follow-up. The results indicate a substantial prevalence of general weight concern and non-trivial rates of cessation related weight concern in Hispanic LITS attempting to quit, and greater success in quitting among those who reported lower rates of cigarettes smoked per month. Copyright © 2014 Elsevier Ltd. All rights reserved.

Influence of aggregate characteristics on the compressive strength of normal weight concrete

International Nuclear Information System (INIS)

Qureshi, M.A.; Aslam, M.

2015-01-01

Experimental investigations on the properties of concrete have been performed around the globe and their correlation is interpreted in relevant design codes. The structural behavior of cement concrete significantly relies on the material resources, properties of the aggregates constituting the concrete and the local construction practice. These factors vary from place to place. Therefore, the compressive strength of concrete prepared from the aggregates available in one locality may not be directly applicable to the other areas. The purpose of this study is to evaluate the Influence of locally available coarse aggregates on the compressive strength of normal weight concrete (NWC) prepared under local environmental conditions of district Khairpur Mir's, Sindh, Pakistan. The coarse aggregates were collected from five different quarries in the vicinity of Khairpur Mir's, Pakistan. In total; 180 cubes were tested. 10 different batches were formed in order to arrange individual characterization of concrete. Each batch was contained of 18 cubes and each quarry contains 2 batches making a total of 36 cube with four different ratios for each quarry. Dry density and compressive strength of concrete was calculated and a comparison is provided as a guideline for the future construction work in the local community. (author)

Compressive strength measurements of hybrid dental composites treated with dry heat and light emitting diodes (LED post cure treatment

Directory of Open Access Journals (Sweden)

Jenny Krisnawaty

2014-11-01

Full Text Available Hybrid composites are mostly used on large cavities as restorative dental materials, whether it is used directly or indirectly. The mechanical properties of composite resin shall increase if it is treated with post cure treatment. The aim of this study is to evaluate compressive strength differences between dry heat and Light Emitting Diodes (LED treatment on the hybrid dental composite. A quasi-experimental was applied on this research with a total of 30 samples that were divided into two groups. Each sample was tested using LLOYD Universal Testing Machine with 1 mm/min speed to evaluate the compressive strength. The compressive strength results were marked when the sample was broken. The results of two groups were then analyzed using t-test statistical calculation. The results of this study show that post cure treatment on hybrid composite using LED light box (194.138 MPa was lower than dry heat treatment (227.339 MPa, which was also significantly different from statistical analysis. It can be concluded that compressive strength of LED light box was lower than dry heat post-cure treatment on the hybrid composite resin.

Tailored Buckling Microlattices as Reusable Light-Weight Shock Absorbers.

Science.gov (United States)

Frenzel, Tobias; Findeisen, Claudio; Kadic, Muamer; Gumbsch, Peter; Wegener, Martin

2016-07-01

Structures and materials absorbing mechanical (shock) energy commonly exploit either viscoelasticity or destructive modifications. Based on a class of uniaxial light-weight geometrically nonlinear mechanical microlattices and using buckling of inner elements, either a sequence of snap-ins followed by irreversible hysteretic - yet repeatable - self-recovery or multistability is achieved, enabling programmable behavior. Proof-of-principle experiments on three-dimensional polymer microstructures are presented. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Strength of "Light" Ferritic and Austenitic Steels Based on the Fe - Mn - Al - C System

Science.gov (United States)

Kaputkina, L. M.; Svyazhin, A. G.; Smarygina, I. V.; Kindop, V. E.

2017-01-01

The phase composition, the hardness, the mechanical properties at room temperature, and the resistance to hot (950 - 1000°C) and warm (550°C) deformation are studied for cast deformable "light" ferritic and austenitic steels of the Fe - (12 - 25)% Mn - (0 - 15)% Al - (0 - 2)% C system alloyed additionally with about 5% Ni. The high-aluminum high-manganese low-carbon and carbonless ferritic steels at a temperature of about 0.5 T melt have a specific strength close to that of the austenitic steels and may be used as weldable scale-resistant and wear-resistant materials. The high-carbon Fe - (20 - 24)% Mn - (5 - 9)% Al - 5% Ni - 1.5% C austenitic steels may be applied as light high-strength materials operating at cryogenic temperatures after a solution treatment and as scale- and heat-resistant materials in an aged condition.

Wind induced fatigue of slender light weight structures in structural dynamics

NARCIS (Netherlands)

Staalduinen, P.C. van; Courage, W.M.G.

1996-01-01

The paper presents a simplified analytical method for calculating the stress ranges in light weight slender structures due to wind loading. The background and assumptions of the method have been explained as well as the derivation of the relevant formula. The application of the simplified method on

The use of light weight deflectometer for in situ evaluation of sand degree of compaction

Directory of Open Access Journals (Sweden)

Amr F. Elhakim

2014-12-01

Full Text Available The light weight deflectometer (LWD, also known as the light falling weight deflectometer, light drop weight tester, and dynamic plate load test, is a hand portable device that was developed in Germany to measure the soil in situ LWD dynamic modulus. Typically, this modulus is used to evaluate the subsoil degree of compaction. Thus it is suitable for compaction quality control of soil-surfaced roads, embankments and replacement fill. As a dynamic test, the device is suited, in particular, for coarse and mixed grained soils with a maximum grain size of 63 mm. The response of poorly graded calcareous and siliceous sands is the focus of this research. First, the index soil properties of the tested soils including grain size distribution; maximum and minimum void ratios and specific gravity were obtained. Petrographic analyses of the tested sands were also performed to determine their mineralogical composition. A 1-m3 chamber was built for performing the LWD testing in the laboratory. The study was performed for relative densities of 20%, 40%, 60% and 80% to represent the behavior of very loose, loose, medium dense and dense sands. The effect of the existence of a rigid boundary beneath the tested soil on test results was also investigated to determine the zone of influence of the light weight deflectometer.

Influence of muscle strength, physical activity and weight on bone mass in a population-based sample of 1004 elderly women.

Science.gov (United States)

Gerdhem, P; Ringsberg, K A M; Akesson, K; Obrant, K J

2003-09-01

High physical activity level has been associated with high bone mass and low fracture risk and is therefore recommended to reduce fractures in old age. The aim of this study was to estimate the effect of potentially modifiable variables, such as physical activity, muscle strength, muscle mass and weight, on bone mass in elderly women. The influence of isometric thigh muscle strength, self-estimated activity level, body composition and weight on bone mineral density (dual energy X-ray absorptiometry; DXA) in total body, hip and spine was investigated. Subjects were 1004 women, all 75 years old, taking part in the Malmö Osteoporosis Prospective Risk Assessment (OPRA) study. Physical activity and muscle strength accounted for 1-6% of the variability in bone mass, whereas weight, and its closely associated variables lean mass and fat mass, to a much greater extent explained the bone mass variability. We found current body weight to be the variable with the most substantial influence on the total variability in bone mass (15-32% depending on skeletal site) in a forward stepwise regression model. Our findings suggest that in elderly women, the major fracture-preventive effect of physical activity is unlikely to be mediated through increased bone mass. Retaining or even increasing body weight is likely to be beneficial to the skeleton, but an excess body weight increase may have negative effects on health. Nevertheless, training in elderly women may have advantages by improving balance, co-ordination and mobility and therefore decreasing the risk of fractures.

Light weight hollow maxillary complete denture: A case series

Directory of Open Access Journals (Sweden)

Laxman Singh Kaira

2012-01-01

Full Text Available Retention, stability and support are the basic principles on which the success of a complete denture relies on. The skill lies in applying these principles efficiently in critical situations. Residual ridge resorption occurs at a three times faster rate in mandibular arch than in the maxillary arch. The severely resorbed maxillary and mandibular edentulous arches that are narrow and constricted with increased interarch space provide decreased support, retention and stability. The consequent weight of the processed complete denture only compromises them further. The severely resorbed jaw can have various treatment options. Extreme resorption of the maxillary denture-bearing area may lead to problems with prosthetic rehabilitation. The advantage of a hollow maxillary or mandibular denture is the reduction of excessive weight of acrylic resin, which normally replaces lost alveolar ridge in the interridge space of the denture wearer. This clinical report describes two case reports of edentulous patients with resorbed ridges where a simplified technique of fabricating a light weight hollow maxillary complete denture was used for the preservation of denture bearing areas.

Strength and Deformability of Light-toned Layered Deposits Observed by MER Opportunity: Eagle to Erebus Craters

Science.gov (United States)

Okubo, C. H.; Schultz, R. A.; Nahm, A. L.

2007-07-01

The strength and deformability of light-toned layered deposits are estimated based on measurements of porosity from Microscopic Imager data acquired by MER Opportunity during its traverse from Eagle Crater to Erebus Crater.

Strength and deformability of light-toned layered deposits observed by MER Opportunity: Eagle to Erebus craters, Mars

Science.gov (United States)

Okubo, Chris H.

2007-10-01

Quantifying host rock deformation is vital to understanding the geologic evolution and productivity of subsurface fluid reservoirs. In support of on-going characterization of fracture controlled fluid flow through the light-toned layered deposits on Mars, key parameters of strength and deformability are derived from Microscopic Imager and Rock Abrasion Tool data collected by the Mars Exploration Rover Opportunity in Meridiani Planum. Analysis of 21 targets of light-toned layered deposits yields a median apparent porosity of 0.25. Additional physical parameters for each target are derived from these porosity measurements. The median value of unconfined compressive strength is 11.23 MPa, Young's modulus is 1.86 GPa, and the brittle-ductile transition pressure is 8.77 MPa.

Effect of ultraviolet light irradiation and sandblasting treatment on bond strengths between polyamide and chemical-cured resin.

Science.gov (United States)

Asakawa, Yuya; Takahashi, Hidekazu; Iwasaki, Naohiko; Kobayashi, Masahiro

2014-01-01

The aim of this study was to evaluate the effects of ultraviolet light (UV) irradiation and sandblasting treatment on the shear bond strength between polyamide and chemical-cured resin. Three types of commercial polyamides were treated using UV irradiation, sandblasting treatment, and a combining sandblasting and UV irradiation. The shear bond strength was measured and analyzed using the Kruskal-Wallis test (α=0.05). Comparing shear bond strengths without surface treatment, from 4.1 to 5.7 MPa, the UV irradiation significantly increased the shear bond strengths except for Valplast, whose shear bond strengths ranged from 5.2 to 9.3 MPa. The sandblasting treatment also significantly increased the shear bond strengths (8.0 to 11.4 MPa). The combining sandblasting and UV irradiation significantly increased the shear bond strengths (15.2 to 18.3 MPa) comparing without surface treatment. This combined treatment was considered the most effective at improving the shear bond strength between polyamide and chemical-cured resin.

Ni Nanobuffer Layer Provides Light-Weight CNT/Cu Fibers with Superior Robustness, Conductivity, and Ampacity.

Science.gov (United States)

Zou, Jingyun; Liu, Dandan; Zhao, Jingna; Hou, Ligan; Liu, Tong; Zhang, Xiaohua; Zhao, Yonghao; Zhu, Yuntian T; Li, Qingwen

2018-03-07

Carbon nanotube (CNT) fiber has not shown its advantage as next-generation light-weight conductor due to the large contact resistance between CNTs, as reflected by its low conductivity and ampacity. Coating CNT fiber with a metal layer like Cu has become an effective solution to this problem. However, the weak CNT-Cu interfacial bonding significantly limits the mechanical and electrical performances. Here, we report that a strong CNT-Cu interface can be formed by introducing a Ni nanobuffer layer before depositing the Cu layer. The Ni nanobuffer layer remarkably promotes the load and heat transfer efficiencies between the CNT fiber and Cu layer and improves the quality of the deposited Cu layer. As a result, the new composite fiber with a 2 μm thick Cu layer can exhibit a superhigh effective strength >800 MPa, electrical conductivity >2 × 10 7 S/m, and ampacity >1 × 10 5 A/cm 2 . The composite fiber can also sustain 10 000 times of bending and continuously work for 100 h at 90% ampacity.

Design and fabrication of light weight current collectors for direct methanol fuel cells using the micro-electro mechanical system technique

Science.gov (United States)

Sung, Min-Feng; Kuan, Yean-Der; Chen, Bing-Xian; Lee, Shi-Min

The direct methanol fuel cell (DMFC) is suitable for portable applications. Therefore, a light weight and small size is desirable. The main objective of this paper is to design and fabricate a light weight current collector for DMFC usage. The light weight current collector mainly consists of a substrate with two thin film metal layers. The substrate of the current collector is an FR4 epoxy plate. The thin film metal layers are accomplished by the thermo coater technique to coat metal powders onto the substrate surfaces. The developed light weight current collectors are further assembled to a single cell DMFC test fixture to measure the cell performance. The results show that the proposed current collectors could even be applied to DMFCs because they are light, thin and low cost and have potential for mass production.

Evaluation of the light weight Juggling system

Directory of Open Access Journals (Sweden)

Erev-Yehene Vered

2011-12-01

Full Text Available This paper presents the training of juggling skills, a highly complex problem of coordination, under tight time and space constraints. This training is achieved with a simple training platform, a light weight juggling platform (LWJ, and is compared to training with real balls. The principle directing the design of the platform is to obtain a simple tool. The simplification, in comparison to real world juggling, is based on the identification of invariant properties in the spatiotemporal coordination of intermediate and expert jugglers. Two classes training solutions were added to the LWJ: An audio-tactile pacing or augmented multimodal environment, and the manipulation of cognitive components of the juggling skills. The transfer to juggling with real balls was evaluated in four different experiments.

Noise and light exposures for extremely low birth weight newborns during their stay in the neonatal intensive care unit.

Science.gov (United States)

Lasky, Robert E; Williams, Amber L

2009-02-01

The objectives of this study were to characterize noise and light levels for extremely low birth weight newborns throughout their stay in the NICU, evaluate factors influencing noise and light levels, and determine whether exposures meet recommendations from the American Academy of Pediatrics. Sound and light were measured inside the beds of extremely low birth weight newborns (n = 22) from birth to discharge. Measurements were recorded for 20 consecutive hours weekly from birth until 36 weeks' postmenstrual age, biweekly until 40 weeks, and every 4 weeks thereafter. Clinical variables including bed type and method of respiratory support were recorded at each session. Age-related changes in respiratory support and bed type explained the weekly increase of 0.22 dB in sound level and 3.67 lux in light level. Old incubators were the noisiest bed types, and new incubators were the quietest. Light levels were significantly higher in open beds than in incubators. The variations in noise and light levels over time were greatest for open beds. Noise and light levels were much less affected by respiratory support in incubators compared with open beds. A typical extremely low birth weight neonate was exposed to noise levels averaging 56.44 dB(A) and light levels averaging 70.56 lux during their stay from 26 to 42 weeks' postmenstrual age in the NICU. Noise levels were rarely within American Academy of Pediatrics recommendations (5.51% of the time), whereas light levels almost always met recommendations (99.37% of the time). Bed type and respiratory support explained differences in noise and light levels that extremely low birth weight newborns experience during their hospital stay. Noise levels exceeded recommendations, although evidence supporting those recommendations is lacking. Well-designed intervention studies are needed to determine the effects of noise reduction on the development of extremely low birth weight newborns.

An investigation into UV light exposure as an experimental model for artificial aging on tensile strength and force delivery of elastomeric chain.

Science.gov (United States)

Wahab, Siti Waznah; Bister, Dirk; Sherriff, Martyn

2014-02-01

This study investigated the effect of ultraviolet type A light (UVA) exposure on the tensile properties of elastomeric chain. UVA light exposure was used as model for artificial aging, simulating prolonged storage of elastomeric chain. Tensile strength (n = 60) was measured after exposing Ormco, Forestadent and 3M chains to UVA light for 0, 2, 3, and 4 weeks. Force decay was measured (n = 60) using chain exposed for 5, 10, and 14 days. The chains were subsequently stretched at a constant distance and the resulting forces measured at 0, 1, 24 hours and 7, 14, 21, and 28 days. This test simulated a clinical scenario of pre-stretching and subsequent shortening of elastomeric chain. Tensile strength had statistically significant difference and was directly related to the duration of ultraviolet (UV) light exposure. Forestadent chain, which had the second highest value for the 'as received' product, showed the most consistent values over time with the lowest degradation. Ormco showed the lowest values for 'as received' as well as after UV exposure; 3M chain had the highest loss of tensile strength. Force decay was also significantly different. UV light exposure of 10 days or more appears to mark a 'watershed' between products: 3M had most survivors, Forestadent chain had some survivors, depending on the time the chain was stretched for. None of the Ormco product survived UV light exposure for more than 5 days. UVA light exposure may be used as a model for artificial aging as it reduces force delivery and tensile strength of exposed chains.

Weighted oscillator strengths and lifetimes for the S IX and S X spectra

International Nuclear Information System (INIS)

Borges, F.O.; Cavalcanti, G.H.; Trigueiros, A.G.

2003-01-01

The weighted oscillator strengths (gf) and the lifetimes presented in this work were carried out in a multi configuration Hartree-Fock relativistic (HFR) approach. In this calculation, the electrostatic parameters were optimized by a least-squares procedure, in order to improve the adjustment to experimental energy levels. This method produces gf-values that are in better agreement with intensity observations and lifetime values that are closer to the experimental ones. In this work, we presented all the experimentally known electric dipole S IX and S X spectral lines

High power light emitting diode (LED) arrays versus halogen light polymerization of oral biomaterials: Barcol hardness, compressive strength and radiometric properties.

Science.gov (United States)

Mills, Robin W; Uhl, Alexander; Blackwell, Gordon B; Jandt, Klaus D

2002-07-01

The clinical performance of light polymerized dental composites is greatly influenced by the quality of the light curing unit (LCU) used. Commonly used halogen LCUs have some specific drawbacks such as decreasing light output with time. This may result in a low degree of monomer conversion of the composites with negative clinical implications. Previous studies have shown that blue light emitting diode (LED) LCUs have the potential to polymerize dental composites without having the drawbacks of halogen LCUs. Since these studies were carried out LED technology has advanced significantly and commercial LED LCUs are now becoming available. This study investigates the Barcol hardness as a function of depth, and the compressive strength of dental composites that had been polymerized for 40 or 20s with two high power LED LCU prototypes, a commercial LED LCU, and a commercial halogen LCU. In addition the radiometric properties of the LCUs were characterized. The two high power prototype LED LCUs and the halogen LCU showed a satisfactory and similar hardness-depth performance whereas the hardness of the materials polymerized with the commercial LED LCU rapidly decreased with sample depth and reduced polymerization time (20 s). There were statistically significant differences in the overall compressive strengths of composites polymerized with different LCUs at the 95% significance level (p = 0.0016) with the two high power LED LCU prototypes and the halogen LCU forming a statistically homogenous group. In conclusion, LED LCU polymerization technology can reach the performance level of halogen LCUs. One of the first commercial LED LCUs however lacked the power reserves of the high power LED LCU prototypes.

Data Base for Light-Weight Automotive Diesel Power Plants: Volume 1. Executive Summary.

Science.gov (United States)

1979-12-01

The effects on fuel economy, emissions, passenger car safety and other variables due to the installation of light-weight Diesel powerplants were studied. Experimental data was obtained on naturally aspirated and turbocharged Diesel engines installed ...

Data Base for Light-Weight Automotive Diesel Power Plants : Volume 3. Miscellaneous Data.

Science.gov (United States)

1979-12-01

The effects of fuel economy, emissions, passenger car safety and other variables due to the installation of light-weight Diesel powerplants were studied. Experimental data was obtained on naturally aspirated and turbocharged Diesel engines installed ...

Orthodontic brackets removal under shear and tensile bond strength resistance tests - a comparative test between light sources

Science.gov (United States)

Silva, P. C. G.; Porto-Neto, S. T.; Lizarelli, R. F. Z.; Bagnato, V. S.

2008-03-01

We have investigated if a new LEDs system has enough efficient energy to promote efficient shear and tensile bonding strength resistance under standardized tests. LEDs 470 ± 10 nm can be used to photocure composite during bracket fixation. Advantages considering resistance to tensile and shear bonding strength when these systems were used are necessary to justify their clinical use. Forty eight human extracted premolars teeth and two light sources were selected, one halogen lamp and a LEDs system. Brackets for premolar were bonded through composite resin. Samples were submitted to standardized tests. A comparison between used sources under shear bonding strength test, obtained similar results; however, tensile bonding test showed distinct results: a statistical difference at a level of 1% between exposure times (40 and 60 seconds) and even to an interaction between light source and exposure time. The best result was obtained with halogen lamp use by 60 seconds, even during re-bonding; however LEDs system can be used for bonding and re-bonding brackets if power density could be increased.

Light-weight aluminium bridges and bridge decks. An overview of recent applications

NARCIS (Netherlands)

Maljaars, J.; Soetens, F.; Kluyver, D. de

2008-01-01

The last decades have shown a large increase in the application of aluminium alloys for light-weight bridges. For bridge construction, aluminium alloys have some specific advantages, but also some points of attention. This paper deals with some recent projects of aluminium bridges, and for these

Do light nuclei display a universal γ-ray strength function?

Directory of Open Access Journals (Sweden)

Voinov A.

2012-02-01

Full Text Available In this work we focus on properties in the quasi-continuum of light nuclei. Generally, both level density and γ-ray strength function (γ-SF differ from nucleus to nucleus. In order to investigate this closer, we have performed particle-γ coincidences using the reactions (p, p', (p, d and (p, t on a 46Ti target. In particular, the very rich data set of the 46Ti(p, p'46Ti inelastic scattering reaction allows analysis of the coincidence data for many independent data sets. Using the Oslo method, we find one common level density for all data sets. If transitions to well-separated low-energy levels are included, the deduced γ-SF may change by a factor of 2 – 3, due strong to Porter-Thomas fluctuations. However, a universal γ-SF with small fluctuations is found provided that only excitation energies above 3 MeV are taken into account. The nuclear structure of the titaniums is discussed within a combinatorial quasi-particle model, showing that only few Nilsson orbitals participate in building up the level density for these light nuclei.

Evaluation of shear bond strength of orthodontic brackets using trans-illumination technique with different curing profiles of LED light-curing unit in posterior teeth.

Science.gov (United States)

Heravi, Farzin; Moazzami, Saied Mostafa; Ghaffari, Negin; Jalayer, Javad; Bozorgnia, Yasaman

2013-11-21

Although using light-cured composites for bonding orthodontic brackets has become increasingly popular, curing light cannot penetrate the metallic bulk of brackets and polymerization of composites is limited to the edges. Limited access and poor direct sight may be a problem in the posterior teeth. Meanwhile, effectiveness of the trans-illumination technique is questionable due to increased bucco-lingual thickness of the posterior teeth. Light-emitting diode (LED) light-curing units cause less temperature rise and lower risk to the pulpal tissue. The purpose of this study was to evaluate the clinical effectiveness of trans-illumination technique in bonding metallic brackets to premolars, using different light intensities and curing times of an LED light-curing unit. Sixty premolars were randomly divided into six groups. Bonding of brackets was done with 40- and 80-s light curing from the buccal or lingual aspect with different intensities. Shear bond strengths of brackets were measured using a universal testing machine. Data were analyzed by one-way analysis of variance test and Duncan's post hoc test. The highest shear bond belonged to group 2 (high intensity, 40 s, buccal) and the lowest belonged to group 3 (low intensity, 40 s, lingual). Bond strength means in control groups were significantly higher than those in experimental groups. In all experimental groups except group 6 (80 s, high intensity, lingual), shear bond strength was below the clinically accepted values. In clinical limitations where light curing from the same side of the bracket is not possible, doubling the curing time and increasing the light intensity during trans-illumination are recommended for achieving acceptable bond strengths.

Daily multi-micronutrient supplementation during tuberculosis treatment increases weight and grip strength among HIV-uninfected but not HIV-infected patients in Mwanza, Tanzania

DEFF Research Database (Denmark)

PrayGod, George; Range, Nyagosya; Faurholt-Jepsen, Daniel

2011-01-01

Undernutrition is common among tuberculosis (TB) patients. The objective of this study was to assess the effect of multi-micronutrient supplementation during TB treatment on weight, body composition, and handgrip strength. A total of 865 patients with smear-positive (PTB+) or -negative (PTB......-) pulmonary TB were randomly allocated to receive a daily biscuit with or without multi-micronutrients for 60 d during the intensive phase of TB treatment. Weight, arm fat area, arm muscle area, and handgrip strength were assessed at baseline and after 2 and 5 mo. At 2 mo, the multi...

Orthodontic brackets removal under shear and tensile bond strength resistance tests – a comparative test between light sources

International Nuclear Information System (INIS)

Silva, P C G; Porto-Neto, S T; Lizarelli, R F Z; Bagnato, V S

2008-01-01

We have investigated if a new LEDs system has enough efficient energy to promote efficient shear and tensile bonding strength resistance under standardized tests. LEDs 470 ± 10 nm can be used to photocure composite during bracket fixation. Advantages considering resistance to tensile and shear bonding strength when these systems were used are necessary to justify their clinical use. Forty eight human extracted premolars teeth and two light sources were selected, one halogen lamp and a LEDs system. Brackets for premolar were bonded through composite resin. Samples were submitted to standardized tests. A comparison between used sources under shear bonding strength test, obtained similar results; however, tensile bonding test showed distinct results: a statistical difference at a level of 1% between exposure times (40 and 60 seconds) and even to an interaction between light source and exposure time. The best result was obtained with halogen lamp use by 60 seconds, even during re-bonding; however LEDs system can be used for bonding and re-bonding brackets if power density could be increased

Data Base for Light-Weight Automotive Diesel Power Plants. Volume 2: Discussion and Results.

Science.gov (United States)

1979-12-01

The effects on fuel economy, emissions, passenger car safety and other variables due to the installation of light-weight Diesel powerplants were studied. Experimental data was obtained on naturally aspirated and turbocharged Diesel engines installed ...

Grip strength is strongly associated with height, weight and gender in childhood : a cross sectional study of 2241 children and adolescents providing reference values

NARCIS (Netherlands)

Ploegmakers, Joris J. W.; Hepping, Ann M.; Geertzen, Jan H. B.; Bulstra, Sjoerd K.; Stevens, Martin

2013-01-01

Question: What are reference values for grip strength in children and adolescents based on a large and heterogeneous study population? What is the association of grip strength with age, gender, weight, and height in this population? Design: Cross-sectional study. Participants: Participants were

Weighted Least Squares Techniques for Improved Received Signal Strength Based Localization

Directory of Open Access Journals (Sweden)

José R. Casar

2011-09-01

Full Text Available The practical deployment of wireless positioning systems requires minimizing the calibration procedures while improving the location estimation accuracy. Received Signal Strength localization techniques using propagation channel models are the simplest alternative, but they are usually designed under the assumption that the radio propagation model is to be perfectly characterized a priori. In practice, this assumption does not hold and the localization results are affected by the inaccuracies of the theoretical, roughly calibrated or just imperfect channel models used to compute location. In this paper, we propose the use of weighted multilateration techniques to gain robustness with respect to these inaccuracies, reducing the dependency of having an optimal channel model. In particular, we propose two weighted least squares techniques based on the standard hyperbolic and circular positioning algorithms that specifically consider the accuracies of the different measurements to obtain a better estimation of the position. These techniques are compared to the standard hyperbolic and circular positioning techniques through both numerical simulations and an exhaustive set of real experiments on different types of wireless networks (a wireless sensor network, a WiFi network and a Bluetooth network. The algorithms not only produce better localization results with a very limited overhead in terms of computational cost but also achieve a greater robustness to inaccuracies in channel modeling.

Effect of different light curing methods on the push-out bond strength of glass fiber post to different root canal regions

Directory of Open Access Journals (Sweden)

Ali Eskandarizadeh

2016-07-01

Full Text Available Background and Aims: Slow polymerization rate in early stage of light curing process leads to higher monomers movement and entering in polymer network that cause higher mechanical properties.The aim of this study was to evaluate the effect of light activation methodes (immediate, 5 and 10 minutes delay on the push-out bond strength of cemented fiber posts in different regions of root canal with two types of resin cements. Materials and Methods: In sixty extracted human single canal, the teeth were decoronated from cement enamel junction and after root canal therapy, FRC postec plus were cemented with two resin cements, Duolink and Variolink 2, in three curing methods; immediate, 5 and 10 minutes of delay. After storing in a dark place for 24 hours, they were cut into three sections: coronal, middle and apical. The push-out bond strength test was performed using a universal testing machine. The failure modes were observed using a stereomicroscope. Data were analyzed using ANOVA and Tukey post hoc test (P0.05. In immediate light curing method, regardless of root region, Duolink had higher push-out bond strength than that of Variolink 2 (P=0.02. In all subgroups, there were reductions in the bond strengths from coronal to apical. Mixed failure at the cement-fiber post interface was predominent in all groups. Conclusion: 5 and 10 minutes delay caused reduction in the push-out bond strength for Variolink 2 but did not have significant effect for Duolink resin cement.

Dim light at night disrupts molecular circadian rhythms and increases body weight.

Science.gov (United States)

Fonken, Laura K; Aubrecht, Taryn G; Meléndez-Fernández, O Hecmarie; Weil, Zachary M; Nelson, Randy J

2013-08-01

With the exception of high latitudes, life has evolved under bright days and dark nights. Most organisms have developed endogenously driven circadian rhythms that are synchronized to this daily light/dark cycle. In recent years, humans have shifted away from the naturally occurring solar light cycle in favor of artificial and sometimes irregular light schedules produced by electric lighting. Exposure to unnatural light cycles is increasingly associated with obesity and metabolic syndrome; however, the means by which environmental lighting alters metabolism are poorly understood. Thus, we exposed mice to dim light at night and investigated changes in the circadian system and metabolism. Here we report that exposure to ecologically relevant levels of dim (5 lux) light at night altered core circadian clock rhythms in the hypothalamus at both the gene and protein level. Circadian rhythms in clock expression persisted during light at night; however, the amplitude of Per1 and Per2 rhythms was attenuated in the hypothalamus. Circadian oscillations were also altered in peripheral tissues critical for metabolic regulation. Exposure to dimly illuminated, as compared to dark, nights decreased the rhythmic expression in all but one of the core circadian clock genes assessed in the liver. Additionally, mice exposed to dim light at night attenuated Rev-Erb expression in the liver and adipose tissue. Changes in the circadian clock were associated with temporal alterations in feeding behavior and increased weight gain. These results are significant because they provide evidence that mild changes in environmental lighting can alter circadian and metabolic function. Detailed analysis of temporal changes induced by nighttime light exposure may provide insight into the onset and progression of obesity and metabolic syndrome, as well as other disorders involving sleep and circadian rhythm disruption.

Metrology and Alignment of Light Weight Grazing Incidence X-Ray Mirrors

Science.gov (United States)

Zhang, William; Content, David; Petre, Robert; Saha, Timo

2000-01-01

Metrology and alignment of light weight X-ray optics have been a challenge for two reasons: (1) that the intrinsic mirror quality and distortions caused by handling can not be easily separated, and (2) the diffraction limits of the visible light become a severe problem at the order of one arc-minute. Traditional methods of using a normal incident pencil or small parallel beam which monitors a tiny fraction of the mirror in question at a given time can not adequately monitor those distortions. We are developing a normal incidence setup that monitors a large fraction, if not the whole, of the mirror at any given time. It will allow us to align thin X-ray mirrors to-an accuracy of a few arc seconds or to a limit dominated by the mirror intrinsic quality.

Objectively measured physical activity and bone strength in 9-year-old boys and girls.

Science.gov (United States)

Sardinha, Luís B; Baptista, Fátima; Ekelund, Ulf

2008-09-01

The purpose of this work was to analyze the relationship between intensity and duration of physical activity and composite indices of femoral neck strength and bone-mineral content of the femoral neck, lumbar spine, and total body. Physical activity was assessed by accelerometry in 143 girls and 150 boys (mean age: 9.7 years). Measurement of bone-mineral content, femoral neck bone-mineral density, femoral neck width, hip axis length, and total body fat-free mass was performed with dual-energy radiograph absorptiometry. Compressive [(bone-mineral density x femoral neck width/weight)] and bending strength [(bone-mineral density x femoral neck width(2))/(hip axis length x weight)] express the forces that the femoral neck has to withstand in weight bearing, whereas impact strength [(bone-mineral density x femoral neck width x hip axis length)/(height x weight)] expresses the energy that the femoral neck has to absorb in an impact from standing height. Analysis of covariance (fat-free mass and age adjusted) showed differences between boys and girls of approximately 9% for compressive, 10% for bending, and 9% for impact strength. Stepwise regression analysis using time spent at sedentary, light, moderate, and vigorous physical activity as predictors revealed that vigorous physical activity explained 5% to 9% of femoral neck strength variable variance in both genders, except for bending strength in boys, and approximately 1% to 3% of total body and femoral neck bone-mineral content variance. Vigorous physical activity was then used to categorize boys and girls into quartiles. Pairwise comparison indicated that boys in the third and fourth quartiles (accumulation of >26 minutes/day) demonstrated higher compressive (11%-12%), bending (10%), and impact (14%) strength than boys in the first quartile. In girls, comparison revealed a difference between the fourth (accumulation of >25 minutes/day) and first quartiles for bending strength (11%). We did not observe any

Finite element simulation of a novel composite light-weight microporous cladding panel

Science.gov (United States)

Tian, Lida; Wang, Dongyan

2018-04-01

A novel composite light-weight microporous cladding panel with matched connection detailing is developed. Numerical simulation on the experiment is conducted by ABAQUS. The accuracy and rationality of the finite element model is verified by comparison between the simulation and the experiment results. It is also indicated that the novel composite cladding panel is of desirable bearing capacity, stiffness and deformability under out-of-plane load.

Study on design of light-weight super-abrasive wheel

Science.gov (United States)

Nohara, K.; Yanagihara, K.; Ogawa, M.

2018-01-01

Fixed-abrasive tool, also called a grinding wheel, is produced by furnacing abrasive compound which contains abrasive grains and binding powder such as vitrified materials or resins. Fixed-abrasive tool is installed on spindle of grinding machine. And it is given 1,800-2,000 min-1 of spindle rotation for the usage. The centrifugal fracture of the compound of fixed- abrasive tool is one of the careful respects in designing. In recent years, however, super-abrasive wheel as a fixed-abrasive tool has been developed and applied widely. One of the most characteristic respects is that metal is applied for the body of grinding-wheel. The strength to hold abrasive grain and the rigidity of wheel become stronger than those of general grinding wheel, also the lifespan of fixed-abrasive tool becomes longer. The weight of fixed-abrasive tool, however, becomes heavier. Therefore, when the super-abrasive wheel is used, the power consumption of spindle motor becomes larger. It also becomes difficult for the grinding-wheel to respond to sudden acceleration or deceleration. Thus, in order to reduce power consumption in grinding and to obtain quicker frequency response of super-abrasive wheel, the new wheel design is proposed. The design accomplishes 46% weight reduction. Acceleration that is one second quicker than that of conventional grinding wheel is obtained.

Optimization of light source parameters in the photodynamic therapy of heterogeneous prostate

International Nuclear Information System (INIS)

Li Jun; Altschuler, Martin D; Hahn, Stephen M; Zhu, Timothy C

2008-01-01

The three-dimensional (3D) heterogeneous distributions of optical properties in a patient prostate can now be measured in vivo. Such data can be used to obtain a more accurate light-fluence kernel. (For specified sources and points, the kernel gives the fluence delivered to a point by a source of unit strength.) In turn, the kernel can be used to solve the inverse problem that determines the source strengths needed to deliver a prescribed photodynamic therapy (PDT) dose (or light-fluence) distribution within the prostate (assuming uniform drug concentration). We have developed and tested computational procedures to use the new heterogeneous data to optimize delivered light-fluence. New problems arise, however, in quickly obtaining an accurate kernel following the insertion of interstitial light sources and data acquisition. (1) The light-fluence kernel must be calculated in 3D and separately for each light source, which increases kernel size. (2) An accurate kernel for light scattering in a heterogeneous medium requires ray tracing and volume partitioning, thus significant calculation time. To address these problems, two different kernels were examined and compared for speed of creation and accuracy of dose. Kernels derived more quickly involve simpler algorithms. Our goal is to achieve optimal dose planning with patient-specific heterogeneous optical data applied through accurate kernels, all within clinical times. The optimization process is restricted to accepting the given (interstitially inserted) sources, and determining the best source strengths with which to obtain a prescribed dose. The Cimmino feasibility algorithm is used for this purpose. The dose distribution and source weights obtained for each kernel are analyzed. In clinical use, optimization will also be performed prior to source insertion to obtain initial source positions, source lengths and source weights, but with the assumption of homogeneous optical properties. For this reason, we compare the

Towards a Light-weight Bag-of-tasks Grid Architecture

Directory of Open Access Journals (Sweden)

I. Bašičević

2015-06-01

Full Text Available The paper presents the application of SIP protocol in the context of bag-of-tasks grid architecture. The SIP protocol has been used in the realization of the execution management service. The main idea is the use of stateful SIP proxy as a request broker. The paper provides a description of the concept, and the prototype system that has been built, as well as the calculation of estimated performance level and its relation to maximum RTT of grid system. The main advantage of this light-weight grid architecture is the reuse of a mature infrastructure. A short overview of some approaches to the mathematical modeling of computer grids is included.

Light Weight Ceramic Ablators for Mars Follow-on Mission Vehicle Thermal Protection System

Science.gov (United States)

Tran, Huy K.; Rasky, Daniel J.; Hsu, Ming-Ta; Turan, Ryan

1994-01-01

New Light Weight Ceramic Ablators (LCA) were produced by using ceramic and carbon fibrous substrates, impregnated with silicone and phenolic resins. The special infiltration techniques (patent pending) were developed to control the amount of organic resins in the highly porous fiber matrices so that the final densities of LCA's range from 0.22 to 0.24 g/cc. This paper presents the thermal and ablative performance of the Silicone Impregnated Reusable Ceramic Ablators (SIRCA) in simulated entry conditions for Mars-Pathfinder in the Ames 60 MW Interaction Heating Facility (I HF). Arc jet test results yielded no evidence of char erosion and mass loss at high stagnation pressures to 0.25 atm. Minimal silica melt was detected on surface char at a stagnation pressure of 0.31 atm. Four ceramic substrates were used in the production of SIRCA's to obtain the effective of boron oxide present in substrate so the thermal performance of SIRCA's. A sample of SIRCA was also exposed to the same heating condition for five cycles and no significant mass loss or recession was observed. Tensile testing established that the SIRCA tensile strength is about a factor of two higher than that of the virgin substrates. Thermogravimetric Analysis (TGA) of the char in nitrogen and air showed no evidence of free carbon in the char. Scanning Electron Microscopy of the post test sample showed that the char surface consists of a fibrous structure that was sealed with a thin layer of silicon oxide melt.

Is handgrip strength normalized to body weight a useful tool to identify dynapenia and functional incapacity in post-menopausal women?

Science.gov (United States)

Dulac, Maude; Boutros, Guy El Hajj; Pion, Charlotte; Barbat-Artigas, Sébastien; Gouspillou, Gilles; Aubertin-Leheudre, Mylène

2016-01-01

To investigate whether handgrip strength normalized to body weight could be a useful clinical tool to identify dynapenia and assess functional capacity in post-menopausal women. A total of 136 postmenopausal women were recruited. Body composition (Dual Energy X-ray Absorptiometry [DEXA], Bio-electrical Impedence Analysis [BIA]), grip strength (dynamometer) and functional capacity (senior fitness tests) were evaluated. Dynapenia was established according to a handgrip strength index (handgrip strength divided by body weight (BW) in Kg/KgBW) obtained from a reference population of young women: Type I dynapenic (<0.44 kg/KgBW) and type II dynapenic (<0.35 kg/KgBW). The results show a positive correlation between handgrip strength index (in kg/KgBW) and alternate-step test (r=0.30, p<0.001), chair-stand test (r=0.25, p<0.005) and one-leg stance test (r=0.335, p<0.001). The results also showed a significant difference in non-dynapenic compared to type I dynapenic and type II dynapenic for the chair-stand test (Non-dynapenic: 12.0±3.0; Type I: 11.7±2.5; Type II: 10.3±3.0) (p=0.037 and p=0.005, respectively) and the one-leg stance test (Non-dynapenic: 54.2±14.2; Type I: 43.8±21.4; Type II: 35.0±21.8) (p=0.030 and p=0.004, respectively). Finally, a significant difference was observed between type II dynapenic and non-dynapenic for the chair-stand test (p=0.032), but not with type I dynapenic. The results showed that handgrip strength was positively correlated with functional capacity. In addition, non-dynapenic women displayed a better functional status when compared to type I and type II dynapenic women. Thus, the determination of the handgrip strength thresholds could be an accessible and affordable clinical tool to identify people at risk of autonomy loss.

Is handgrip strength normalized to body weight a useful tool to identify dynapenia and functional incapacity in post-menopausal women?

Directory of Open Access Journals (Sweden)

Maude Dulac

Full Text Available ABSTRACT Objective To investigate whether handgrip strength normalized to body weight could be a useful clinical tool to identify dynapenia and assess functional capacity in post-menopausal women. Method A total of 136 postmenopausal women were recruited. Body composition (Dual Energy X-ray Absorptiometry [DEXA], Bio-electrical Impedence Analysis [BIA], grip strength (dynamometer and functional capacity (senior fitness tests were evaluated. Dynapenia was established according to a handgrip strength index (handgrip strength divided by body weight (BW in Kg/KgBW obtained from a reference population of young women: Type I dynapenic (<0.44 kg/KgBW and type II dynapenic (<0.35 kg/KgBW. Results The results show a positive correlation between handgrip strength index (in kg/KgBW and alternate-step test (r=0.30, p<0.001, chair-stand test (r=0.25, p<0.005 and one-leg stance test (r=0.335, p<0.001. The results also showed a significant difference in non-dynapenic compared to type I dynapenic and type II dynapenic for the chair-stand test (Non-dynapenic: 12.0±3.0; Type I: 11.7±2.5; Type II: 10.3±3.0 (p=0.037 and p=0.005, respectively and the one-leg stance test (Non-dynapenic: 54.2±14.2; Type I: 43.8±21.4; Type II: 35.0±21.8 (p=0.030 and p=0.004, respectively. Finally, a significant difference was observed between type II dynapenic and non-dynapenic for the chair-stand test (p=0.032, but not with type I dynapenic. Conclusion The results showed that handgrip strength was positively correlated with functional capacity. In addition, non-dynapenic women displayed a better functional status when compared to type I and type II dynapenic women. Thus, the determination of the handgrip strength thresholds could be an accessible and affordable clinical tool to identify people at risk of autonomy loss.

Influence of silica fume on the strength of high strength concrete

International Nuclear Information System (INIS)

Akram, T.; Memon, S.A.; Khan, S.A.

2007-01-01

HSC (High Strength Concrete) does not become evident by a sudden change in the behavior of 'ordinary strength' concrete. There is a gradual effect that becomes more noticeable when the strength level exceeds about 40-45 MPa. There cannot be a precise level of strength which defines this change in effect. The effects are on strength and workability, requiring us to take into account in our mix proportioning, the ramifications of fineness of cement on workability and of type of aggregate and aggregate/cement ratio on strength. In fact, the selection of materials becomes more critical as the concrete strength increases and that if very high strength is required (100 MPa and higher), relatively few materials may be suitable. An experimental investigation is carried out to evaluate the feasibility of producing HSC using locally available materials and to study the influence of silica fume on the strength of HSC. The main variables in this research is amount of silica fume. The parameters that are kept constant are the amount of cement equal to 580 kg/m3, dosage of HRWRA (High Range Water Reducing Admictures) equal to 4 % by weight of cementitious materials and the ratio of fine aggregate to coarse aggregate (1:2.3). Test results revealed that it is feasible to produce HSC using locally available materials. The optimum percentage of silica fume was found to be 15 % by weight of cement. (author)

The interfacial strength of carbon nanofiber epoxy composite using single fiber pullout experiments.

Science.gov (United States)

Manoharan, M P; Sharma, A; Desai, A V; Haque, M A; Bakis, C E; Wang, K W

2009-07-22

Carbon nanotubes and nanofibers are extensively researched as reinforcing agents in nanocomposites for their multifunctionality, light weight and high strength. However, it is the interface between the nanofiber and the matrix that dictates the overall properties of the nanocomposite. The current trend is to measure elastic properties of the bulk nanocomposite and then compare them with theoretical models to extract the information on the interfacial strength. The ideal experiment is single fiber pullout from the matrix because it directly measures the interfacial strength. However, the technique is difficult to apply to nanocomposites because of the small size of the fibers and the requirement for high resolution force and displacement sensing. We present an experimental technique for measuring the interfacial strength of nanofiber-reinforced composites using the single fiber pullout technique and demonstrate the technique for a carbon nanofiber-reinforced epoxy composite. The experiment is performed in situ in a scanning electron microscope and the interfacial strength for the epoxy composite was measured to be 170 MPa.

Reliability of Strength Testing using the Advanced Resistive Exercise Device and Free Weights

Science.gov (United States)

English, Kirk L.; Loehr, James A.; Laughlin, Mitzi A.; Lee, Stuart M. C.; Hagan, R. Donald

2008-01-01

The Advanced Resistive Exercise Device (ARED) was developed for use on the International Space Station as a countermeasure against muscle atrophy and decreased strength. This investigation examined the reliability of one-repetition maximum (1RM) strength testing using ARED and traditional free weight (FW) exercise. Methods: Six males (180.8 +/- 4.3 cm, 83.6 +/- 6.4 kg, 36 +/- 8 y, mean +/- SD) who had not engaged in resistive exercise for at least six months volunteered to participate in this project. Subjects completed four 1RM testing sessions each for FW and ARED (eight total sessions) using a balanced, randomized, crossover design. All testing using one device was completed before progressing to the other. During each session, 1RM was measured for the squat, heel raise, and deadlift exercises. Generalizability (G) and intraclass correlation coefficients (ICC) were calculated for each exercise on each device and were used to predict the number of sessions needed to obtain a reliable 1RM measurement (G . 0.90). Interclass reliability coefficients and Pearson's correlation coefficients (R) also were calculated for the highest 1RM value (1RM9sub peak)) obtained for each exercise on each device to quantify 1RM relationships between devices.

Impact of Weight Loss on Physical Function with Changes in Strength, Muscle Mass, and Muscle Fat Infiltration in Overweight to Moderately Obese Older Adults: A Randomized Clinical Trial

Directory of Open Access Journals (Sweden)

Adam J. Santanasto

2011-01-01

Full Text Available Purpose. Evaluate the effects of weight loss on muscle mass and area, muscle fat infiltration, strength, and their association with physical function. Methods. Thirty-six overweight to moderately obese, sedentary older adults were randomized into either a physical activity plus weight loss (PA+WL or physical activity plus successful aging health education (PA+SA program. Measurements included body composition by dual-energy X-ray absorptiometry, computerized tomography, knee extensor strength, and short physical performance battery (SPPB. Results. At 6 months, PA+WL lost greater thigh fat and muscle area compared to PA+SA. PA+WL lost 12.4% strength; PA+SA lost 1.0%. Muscle fat infiltration decreased significantly in PA+WL and PA+SA. Thigh fat area decreased 6-fold in comparison to lean area in PA+WL. Change in total SPPB score was strongly inversely correlated with change in fat but not with change in lean or strength. Conclusion. Weight loss resulted in additional improvements in function over exercise alone, primarily due to loss of body fat.

A light/dark cycle in the NICU accelerates body weight gain and shortens time to discharge in preterm infants.

Science.gov (United States)

Vásquez-Ruiz, Samuel; Maya-Barrios, José Alfonso; Torres-Narváez, Patricia; Vega-Martínez, Benito Rubén; Rojas-Granados, Adelina; Escobar, Carolina; Angeles-Castellanos, Manuel

2014-09-01

Bright constant light levels in the NICU may have negative effects on the growth and development of preterm infants The aim of this study is to evaluate the benefits of an alternating light/dark cycle in the NICU on weight gain and early discharge from the therapy in premature infants. A randomized interventional study was designed comparing infants in the NICU of Hospital Juarez de México, exposed from birth either to an LD environment (LD, n=19) or to the traditional continuous light (LL, n=19). The LD condition was achieved by placing individual removable helmets over the infant's heads. Body weight gain was analyzed, as the main indicator of stability and the main criteria for discharge in preterm infants born at 31.73±0.31week gestational age. Infants maintained in an LD cycle gained weight faster than infants in LL and therefore attained a shorter hospital stay, (34.37±3.12 vs 51.11±5.29days; P>0.01). Also, LD infants exhibited improved oxygen saturation and developed a daily melatonin rhythm. These findings provide a convenient alternative for establishing an LD environment for preterm healthy newborns in the NICU and confirm the beneficial effects of an alternating LD cycle for growth and weight gain and for earlier discharge time. Here we provide an easy and practical alternative to implement light/dark conditions in the NICU. Copyright © 2014 Elsevier Ltd. All rights reserved.

The effect of energy-protein supplementation on weight, body composition and handgrip strength among pulmonary tuberculosis HIV-co-infected patients

DEFF Research Database (Denmark)

PrayGod, George; Range, Nyagosya; Faurholt-Jepsen, Daniel

2012-01-01

Undernutrition is common among smear-positive pulmonary tuberculosis (PTB+) patients. Micronutrient supplementation may improve treatment outcomes, but it is unclear whether additional energy-protein would be beneficial. The present study aimed to assess the effect of energy-protein supplementation...... on weight, body composition and handgrip strength against a background of high micronutrient intake during tuberculosis (TB) treatment. A total of 377 PTB+ patients co-infected with HIV were randomly allocated one or six biscuits daily for 60 d during TB treatment. Weight, arm fat area, arm muscle area...

Effect of ultraviolet light irradiation period on bond strengths between fiber-reinforced composite post and core build-up composite resin.

Science.gov (United States)

Asakawa, Yuya; Takahashi, Hidekazu; Iwasaki, Naohiko; Kobayashi, Masahiro

2014-01-01

The aim of the present study was to characterize the effects of the ultraviolet light (UV) irradiation period on the bond strength of fiber-reinforced composite (FRC) posts to core build-up resin. Three types of FRC posts were prepared using polymethyl methacrylate, urethane dimethacrylate, and epoxy resin. The surfaces of these posts were treated using UV irradiation at a distance of 15 mm for 0 to 600 s. The pull-out bond strength was measured and analyzed with the Dunnett's comparison test (α=0.05). The bond strengths of the post surfaces without irradiation were 6.9 to 7.4 MPa; those after irradiation were 4.2 to 26.1 MPa. The bond strengths significantly increased after 15 to 120-s irradiation. UV irradiation on the FRC posts improved the bond strengths between the FRC posts and core build-up resin regardless of the type of matrix resin.

Light-weight radioisotope heater impact tests

International Nuclear Information System (INIS)

Reimus, M.A.H.; Rinehart, G.H.; Herrera, A.

1998-01-01

The light-weight radioisotope heater unit (LWRHU) is a 238 PuO 2 -fueled heat source designed to provide one thermal watt in each of various locations on a spacecraft. Los Alamos National Laboratory designed, fabricated, and safety tested the LWRHU. The heat source consists of a hot-pressed 238 PuO 2 fuel pellet, a Pt-30Rh vented capsule, a pyrolytic graphite insulator, and a fineweave-pierced fabric graphite aeroshell assembly. To compare the performance of the LWRHUs fabricated for the Cassini mission with the performance of those fabricated for the Galileo mission, and to determine a failure threshold, two types of impact tests were conducted. A post-reentry impact test was performed on one of 180 flight-quality units produced for the Cassini mission and a series of sequential impact tests using simulant-fueled LWRHU capsules were conducted respectively. The results showed that deformation and fuel containment of the impacted Cassini LWRHU was similar to that of a previously tested Galileo LWRHU. Both units sustained minimal deformation of the aeroshell and fueled capsule; the fuel was entirely contained by the platinum capsule. Sequential impacting, in both end-on and side-on orientations, resulted in increased damage with each subsequent impact. Sequential impacting of the LWRHU appears to result in slightly greater damage than a single impact at the final impact velocity of 50 m/s

Relationship between the tensile strengths and diameters of human umbilical cords.

Science.gov (United States)

Fernando, D M G; Gamage, S M K; Ranmohottige, S; Weerakkody, I; Abeyruwan, H; Parakrama, H

2018-05-01

Mothers of alleged infanticides might claim that umbilical cord broke during precipitate delivery causing injuries detected on baby at autopsy. There is paucity of evidence regarding this possibility. The objective of the study was to determine relationship between tensile strength and diameter or weight per unit length of cord. Diameters and weights per unit length of fresh umbilical cords were determined. Tensile strengths were measured by Hounsfield Testing Machine. Relationship between tensile strength versus cord diameter and weight per unit length were analyzed. Of 122 cords, average tensile strength, diameter and weight per centimeter were 50.4 N, 7.73 mm and 6.87 g respectively. The tensile strengths were directly proportional to diameter. There was no association between tensile strength and weight per centimeter. Measurement of the diameter of cord is important during autopsy to predict tensile strength and thereby to presume whether cord could have broken by the weight of the baby. Copyright © 2018 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Ultra-light-weight high torque density brushless PM machine design: considering driving-cycle of a four-wheel drive race car (EVER15-138)

NARCIS (Netherlands)

Paulides, J.J.H.; Encica, L.; Beernaert, T.F.; Velden, van der H.H.F.; Parfant, A.G.P.; Lomonova, E.A.

2015-01-01

This paper explores the design of an ultra-light-weight power and torque dense motor to enhance the performance of a light-weight electric racing vehicle. Such a racing vehicle is to compete in formula student racing events. The state-of-the-art powertrain in these vehicles are axial-field machines

Influence of Post Weld Heat Treatment on Strength of Three Aluminum Alloys Used in Light Poles

Directory of Open Access Journals (Sweden)

Craig C. Menzemer

2016-03-01

Full Text Available The conjoint influence of welding and artificial aging on mechanical properties were investigated for extrusions of aluminum alloy 6063, 6061, and 6005A. Uniaxial tensile tests were conducted on the aluminum alloys 6063-T4, 6061-T4, and 6005A-T1 in both the as-received (AR and as-welded (AW conditions. Tensile tests were also conducted on the AR and AW alloys, subsequent to artificial aging. The welding process used was gas metal arc (GMAW with spray transfer using 120–220 A of current at 22 V. The artificial aging used was a precipitation heat treatment for 6 h at 182 °C (360 °F. Tensile tests revealed the welded aluminum alloys to have lower strength, both for yield and ultimate tensile strength, when compared to the as-received un-welded counterpart. The beneficial influence of post weld heat treatment (PWHT on strength and ductility is presented and discussed in terms of current design provisions for welded aluminum light pole structures.

NRL Hyperspectral Imagery Trafficability Tool (HITT): Software andSpectral-Geotechnical Look-up Tables for Estimation and Mapping of Soil Bearing Strength from Hyperspectral Imagery

Science.gov (United States)

2012-09-28

light weight deflectometer ( LWD )) for recording bearing strength (dynamic deflection modulus). (Middle row) Waimanalo Bay, HI: (left) ASD spectrometer...recording reflectance from backpack configuration; (right) view of the LWD and the data recording unit. (Bottom row, middle) core sample used for...grain size profiles and moisture analysis, flanked by (left) LWD with weight prepared for drop test, and (right) shear measurements with a dynamic

Experimental study on p-wave neutron strength functions for light nuclei

International Nuclear Information System (INIS)

Koester, L.; Waschkowski, W.; Meier, J.; Rau, G.; Salehi, M.

1988-01-01

Broad energy distributions in fast neutron beams have been achieved by appropriate filtering of the 236 U fission radiation provided from the RENT converter facility at the FRM research reactor. Transmission measurements in such beams result in average cross sections to which resonance reactions and shape elastic scattering contribute. We used a silicon (124.5 cm) filtered beam with a median energy of 143 keV (width 20 keV) and beams with 1.3 MeV (0.55 to 3 MeV) and 2.1 MeV (1 to 5.5 MeV) obtained through different filter combinations of lead and polyethylene. The relative high energies and the broad spectra made it possible to determine experimentally the contributions of s- and p-wave resonance reactions to the average cross section even for light nuclei. Using the three different beams we determined the average cross sections for the elements in the mass region A = 9 to 65. Analysing the measured cross sections by means of the R matrix formalism provided a complete set of p-wave strength functions and distant level parameters. Moreover, single particle shell effects in the cross sections were observed. In conclusion we obtained information on the 2P and the 3S size resonances and about the validity of the optical model for neutron reactions with light nuclei. (orig.)

Managing Knee Osteoarthritis: The Effects of Body Weight Supported Physical Activity on Joint Pain, Function, and Thigh Muscle Strength.

Science.gov (United States)

Peeler, Jason; Christian, Mathew; Cooper, Juliette; Leiter, Jeffrey; MacDonald, Peter

2015-11-01

To determine the effect of a 12-week lower body positive pressure (LBPP)-supported low-load treadmill walking program on knee joint pain, function, and thigh muscle strength in overweight patients with knee osteoarthritis (OA). Prospective, observational, repeated measures investigation. Community-based, multidisciplinary sports medicine clinic. Thirty-one patients aged between 55 and 75 years, with a body mass index ≥25 kg/m and mild-to-moderate knee OA. Twelve-week LBPP-supported low-load treadmill walking regimen. Acute knee joint pain (visual analog scale) during full weight bearing treadmill walking, chronic knee pain, and joint function [Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire] during normal activities of daily living, and thigh muscle strength (isokinetic testing). Appropriate methods of statistical analysis were used to compare data from baseline and follow-up evaluation. Participants reported significant improvements in knee joint pain and function and demonstrated significant increases in thigh muscle strength about the degenerative knee. Participants also experienced significant reductions in acute knee pain during full weight bearing treadmill walking and required dramatically less LBPP support to walk pain free on the treadmill. Data suggest that an LBPP-supported low-load exercise regimen can be used to significantly diminish knee pain, enhance joint function, and increase thigh muscle strength, while safely promoting pain-free walking exercise in overweight patients with knee OA. These findings have important implications for the development of nonoperative treatment strategies that can be used in the management of joint symptoms associated with progressive knee OA in at-risk patient populations. This research suggests that LBPP-supported low-load walking is a safe user-friendly mode of exercise that can be successfully used in the management of day-to-day joint symptoms associated with knee OA, helping to improve the

Influence of light-weight organic matters on strontium sorption to bentonite

International Nuclear Information System (INIS)

Wang, Tsing-Hai; Wu, Ding-Chiang; Teng, Shi-Ping

2010-01-01

Document available in extended abstract form only. Light-weight organic matters were frequently observed in groundwater. Their existence had significant influence on the transport of radionuclides. In this study, light-weight organic acid species including oxalic (MW 90), succinic (MW 118), adipic (MW 146), azelaic (MW 188), eicosanedioic (MW 306), benzoic (MW 122), salicylic (MW 138), and gallic (MW 170) were selected as the surrogate of natural organic matters. Their effects on strontium sorption to bentonite were evaluated by using a surface complexation model MINEQL+. Under this framework, three sorption mechanisms were considered: 1. structure sorption sites, 2. edge sorption sites, 3. further hydration of adsorbed Sr 2+ . The presence of organic species had no influence on Sr cation sorption to structure sorption sites. However, Sr cation sorption to edge sorption was affected by the organics to certain extent. For example, sorption capability of edge sites toward Sr was increased by the gallic species. Furthermore, hydration of adsorbed Sr was significantly affected by the presence of organic species. This might relate to that adsorbed Sr would become the bridge associating organic species on bentonite surfaces, but this argument required more solid spectral evidences to support. Some preliminary observations on Sr sorption to bentonite were obtained in this work; however, further experiments are still required by conducting experiments with more variety of organic species. By doing a comprehensive study, it would be much beneficial to make a more accurate evaluation of the influence of organic matters on Sr sorption

Evaluation of physical property of light-weight soil with air foam using X-ray CT method

International Nuclear Information System (INIS)

Otani, Jun; Mukunoki, Toshifumi; Kikuchi, Yoshiaki

2000-01-01

The objective of this paper is to investigate the physical property of light-weight soil made of dredged slurry mixed with air foam and cement using X-ray CT method. In this study, not only the specimen made in laboratory but also the one sampled at the in-situ construction site were used and the property in the soil was visualized and the distributions of the density an air porosity were evaluated quantitatively using the results of CT scanning. Here, the method of image processing analysis was also used for this evaluation study. Based on the results obtained in this study, it is concluded that the X-ray CT method is a powerful tool even for geotechnical engineering and this makes not only the visualization but also the quantitative ion discussion possible for the light-weight soil with air foam. (author)

Improvement of the adhesion strength between copper plated layer and resin substrate using a chemically adsorbed monolayer

Directory of Open Access Journals (Sweden)

Tsuchiya K.

2013-08-01

Full Text Available With reducing the size and weight of electric devices, high-tensile, light and fine copper wire is demanded. So the production technique of a copper wire plated on a super fiber resin (Vectran film was researched for improving the adhesion strength between the copper and the resin. In this study, we used the Cu2+ or Pd2+ complex prepared with a chemically adsorbed monolayer (CAM to improve the adhesion strength between the copper plated layer and the Vectran film. As the result of scotch tape test, it was observed that the adhesion strength between the copper plated layer and Vectran film was improved by the Cu2+ or Pd2+ complex CAM.

The influence of aggregates type on W/C ratio on the strength and other properties of concrete

Science.gov (United States)

Malaiskiene, J.; Skripkiunas, G.; Vaiciene, M.; Karpova, E.

2017-10-01

The influence of different types of aggregates and W/C ratio on concrete properties is analysed. In order to achieve this aim, lightweight (with expanded clay aggregate) and normal concrete (with gravel aggregate) mixtures are prepared with different W/C ratios. Different W/C ratios are selected by reducing the amount of cement when the amount of water is constant. The following properties of concrete have been determined: density, compressive strength and water absorption. Additionally, the statistical data analysis is performed and influence of aggregate type and W/C ratio on concrete properties is determined. The empirical equations indicating dependence between concrete strength and W/C and strength of aggregate are obtained for normal concrete and light-weight concrete.

Light weight radioisotope heater unit (LWRHU) production for the Cassini mission

International Nuclear Information System (INIS)

Rinehart, G.H.

1997-01-01

The Light-Weight Radioisotope Heater Unit (LWRHU) is a [sup 238]PuO[sub 2] fueled heat source designed to provide one thermal watt in each of various locations on a spacecraft. The heat sources are required to maintain the temperature of specific components within normal operating ranges. The heat source consists of a hot- pressed [sup 238]PuO[sub 2] fuel pellet, a Pt-3ORh vented capsule, a pyrolytic graphite insulator, and a woven graphite aeroshell assembly. Los Alamos National Laboratory has fabricated 180 heat sources, 157 of which will be used on the Cassini mission

Effects of lighting and air-conditioning systems on growth weight and functional composition of frill-lettuce produced in plant factory

Science.gov (United States)

Yoshida, Atsumasa; Okamura, Nobuya; Furukawa, Hajime; Myojin, Chiho; Moriuchi, Koji; Kinoshita, Shinichi

2017-06-01

The aim of the present study was to develop optimal air-conditioning systems for plant factories. To verify the effect of particular air-conditioning and lighting systems, cultivation experiments were performed with frill-lettuce for two weeks. In the present study, the relationship between the cultivation condition, the yield (i.e., increase in edible portion weight), and the functional components were discussed. Based on the measured data, increased photosynthetic photon flux density increased antioxidative activity and edible portion weight, possibly because high light intensities are stressful for frill lettuce. Antioxidative activity also increased under conditions of low CO2 concentration, weak and strong winds, and high air temperature because these conditions became stresses for the plants. However, a decrease in edible portion weight was observed under these conditions, implying there is a negative correlation between antioxidative activity and edible portion weight.

Laser beam welding of new ultra-high strength and supra-ductile steels

Science.gov (United States)

Dahmen, Martin

2015-03-01

Ultra-high strength and supra-ductile are entering fields of new applications. Those materials are excellent candidates for modern light-weight construction and functional integration. As ultra-high strength steels the stainless martensitic grade 1.4034 and the bainitic steel UNS 53835 are investigated. For the supra-ductile steels stand two high austenitic steels with 18 and 28 % manganese. As there are no processing windows an approach from the metallurgical base on is required. Adjusting the weld microstructure the Q+P and the QT steels require weld heat treatment. The HSD steel is weldable without. Due to their applications the ultra-high strength steels are welded in as-rolled and strengthened condition. Also the reaction of the weld on hot stamping is reflected for the martensitic grades. The supra-ductile steels are welded as solution annealed and work hardened by 50%. The results show the general suitability for laser beam welding.

Weight reduction of automobile parts using light metals. Keikinzoku shiyo ni yoru jidosha buhin no keiryoka

Energy Technology Data Exchange (ETDEWEB)

Hayashi, S [Toyota Motor Corp., Aichi (Japan)

1992-12-25

Weight reduction of automobiles is required from the viewpoint of reduction of CO2 emission and energy conservation. Comparing a car with another one of almost the same size and performance with 1% reduced weight, combustion efficiency of the latter can be improved by 0.5-0.8%. This report introduces several examples, in which steel parts are replaced with light alloy parts to reduce car weight, and describes the future perspective. Concerning a cylinder block which is the heaviest part among engine parts, a block made of aluminum alloy with no cast liner has been developed. There is also an example of an oil pan adopting aluminum die-cast for a part of it. A valve lifter made of aluminum alloy has been developed for valve system parts and has contributed to friction loss, noise reduction, and improvement of fuel consumption. As for steering system parts, a steering bracket made of Mg alloy die-cast has been developed. The use of light alloy parts, in general, increases material cost. Therefore it is now required to build up closer connection between designs and production techniques and to improve reliability of casting and forging technologies. 5 refs., 20 figs.

Design optimization on the drive train of a light-weight robotic arm

DEFF Research Database (Denmark)

Zhou, Lelai; Bai, Shaoping; Hansen, Michael Rygaard

2011-01-01

A drive train optimization method for design of light-weight robots is proposed. Optimal selections of motors and gearboxes from a limited catalog of commercially available components are done simultaneously for all joints of a robotic arm. Characteristics of the motor and gearbox, including gear...... ratio, gear inertia, motor inertia, and gear efficiency, are considered in the drive train modeling. A co-simulation method is developed for dynamic simulation of the arm. A design example is included to demonstrate the proposed design optimization method....

Ultra High Temperature and Multifunctional Ceramic Matrix Composite – Coating Systems for Light-Weight Space and Aero Systems

Data.gov (United States)

National Aeronautics and Space Administration — Revolutionary ultra-high temperature, high mechanical loading capable, oxidation resistant, durable ceramic coatings and light-weight fiber-reinforced Ceramic Matrix...

Atmospheric profiles of Black Carbon at remote locations using light-weight airborne Aethalometers

Science.gov (United States)

Hansen, A. D.; Močnik, G.; Drinovec, L.; Lenarcic, M.

2012-12-01

While measurements of atmospheric aerosols are routinely performed at ground-level around the world, there is far less knowledge of their concentrations at altitude: yet this data is a crucial requirement for our understanding of the dispersion of pollutants of anthropogenic origin, with their associated effects on radiative forcing, cloud condensation, and other adverse phenomena. Black Carbon (BC) is a unique tracer for combustion emissions, and can be detected rapidly and with great sensitivity by filter-based optical methods. It has no non-combustion sources and is not transformed by atmospheric processes. Recent technical advances have developed light-weight miniaturized instruments which can be operated on light aircraft or carried aboard commercial passenger flights. From January to April 2012, a single-seat ultra-light aircraft flew around the world on a scientific, photographic and environmental-awareness mission. The flight track crossed all seven continents and all major oceans, with altitudes up to 8.9 km ASL. The aircraft carried a custom-developed high-sensitivity dual-wavelength light-weight Aethalometer, operating at 370 and 880 nm with special provision to compensate for the effects of changing pressure, temperature and humidity. The instrument recorded BC concentrations with high temporal resolution and sensitivity better than 5 ng/m3. We present examples of data from flight tracks over remote oceans, uninhabited land masses, and densely populated areas, analyzing the spectral dependence of absorption to infer the contributions to BC from fossil fuel vs. biomass combustion, and aggregating the data into vertical profiles. The regional and long range transport of BC may be investigated using back-trajectories. We have also operated miniature instruments in the passenger cabins of long-distance commercial aircraft. Since there are no combustion sources within the cabin, any BC in the ventilation air must necessarily have originated from the outside

Compact, Light-weight and Cost-effective Microscope based on Lensless Incoherent Holography for Telemedicine Applications

Science.gov (United States)

Mudanyali, Onur; Tseng, Derek; Oh, Chulwoo; Isikman, Serhan O.; Sencan, Ikbal; Bishara, Waheb; Oztoprak, Cetin; Seo, Sungkyu; Khademhosseini, Bahar; Ozcan, Aydogan

2010-01-01

Despite the rapid progress in optical imaging, most of the advanced microscopy modalities still require complex and costly set-ups that unfortunately limit their use beyond well equipped laboratories. In the meantime, microscopy in resource-limited settings has requirements significantly different from those encountered in advanced laboratories, and such imaging devices should be cost-effective, compact, light-weight and appropriately accurate and simple to be usable by minimally trained personnel. Furthermore, these portable microscopes should ideally be digitally integrated as part of a telemedicine network that connects various mobile health-care providers to a central laboratory or hospital. Toward this end, here we demonstrate a lensless on-chip microscope weighing ~46 grams with dimensions smaller than 4.2cm × 4.2cm × 5.8cm that achieves sub-cellular resolution over a large field of view of ~24 mm2. This compact and light-weight microscope is based on digital in-line holography and does not need any lenses, bulky optical/mechanical components or coherent sources such as lasers. Instead, it utilizes a simple light-emitting-diode (LED) and a compact opto-electronic sensor-array to record lensless holograms of the objects, which then permits rapid digital reconstruction of regular transmission or differential interference contrast (DIC) images of the objects. Because this lensless incoherent holographic microscope has orders-of-magnitude improved light collection efficiency and is very robust to mechanical misalignments it may offer a cost-effective tool especially for telemedicine applications involving various global health problems in resource limited settings. PMID:20401422

Association of light-to-moderate alcohol drinking in pregnancy with preterm birth and birth weight

DEFF Research Database (Denmark)

Strandberg-Larsen, Katrine; Poulsen, Gry; Bech, Bodil Hammer

2017-01-01

Women who drink light-to-moderately during pregnancy have been observed to have lower risk of unfavourable pregnancy outcomes than abstainers. This has been suggested to be a result of bias. In a pooled sample, including 193 747 live-born singletons from nine European cohorts, we examined...... alcohol. This decreased to 39% in 2000–2004, and 14% in 2005–2011. Before 2000, every additional drink was associated with reduced mean birth weight, whereas in 2005–2011, the mean birth weight increased with increasing intake. The period-specific associations between low-to-moderate drinking and birth...

Efficacy of manual versus free-weight training to improve maximal strength and performance for microgravity conditions.

Science.gov (United States)

Behringer, Michael; Schüren, Thomas; McCourt, Molly; Mester, Joachim

2016-01-01

We tested a simple and compact device designed for manual resistance training in conditions of microgravity (Self-Powered Rope Trainer Duo (SPoRT Duo)) to increase muscle performance. Twenty-four participants (20.8 ± 2.1 years) were randomly assigned to a manual resistance group (n = 12) and a free-weight group (n = 12). Participants performed eight exercises (three sets; 8-12 efforts) either with free weights or the SPoRT Duo twice a week for 6 weeks. Maximal isometric force of trunk flexion, back extension and chest press increased (P at least 0.01, d at least 0.52) both in the manual resistance group (18.4% ± 15.0%; 32.7% ± 22.7%; 15.3% ± 9.7%) and free-weight group (18.0% ± 13.9%; 26.6% ± 28.9%; 13.3% ± 7.6%). The change in maximal isometric force of wide grip row in both groups (d at best 0.38) did not reach statistical significance (P at best 0.08). The squat one-repetition-maximum increased in the manual resistance group (29.8% ± 22.1%) and the free-weight group (32.4% ± 26.6%). Jump height, determined by a jump-and-reach test, increased in the free-weight group (9.8% ± 13.2%) but not in the manual resistance group (2.0% ± 8.5%). Manual resistance training was equally effective in increasing strength as traditional resistance training with free weights. This apparatus is a useful addition to current in-flight exercise systems.

Ultra light weight refractory material for high temperature applications

Energy Technology Data Exchange (ETDEWEB)

Finke, V.; Kern, H. [Rath GmbH, Meissen (Germany); Springer, M. [Aug. Rath jun. GmbH, Vienna (Austria)

2007-07-01

The requirements on companies running high temperature processes, i.e. at temperatures about 1000 C and above, have increased dramatically within the last few years. For technological, economical and ecological purposes each application has to be checked carefully. As well the political discussion regarding environmental pollution, greenhouse effect and emission trading and the guidelines for climate and environmental protection exert massive influence on thermal process technology and pose an appropriate challenge for the companies. Next to costs of labour and raw materials the costs for energy and environmental costs play a decisive role more and more. The pressure on the management thereby incurred may have a lasting effect on innovations regarding increase of energy efficiency, decrease of CO{sub 2}-emission and often on non negligible increase of productivity. Mainly against the background of the highly scheduled European aims for emission reduction and also in consideration of the still proceeding globalisation the usage of state-of-the-art refractory technics in thermal process technology is of particular importance for business success, for reducing of environmental impact and last but not least for conservation and safeguarding of jobs in Europe and Germany. The applications for products made from high-temperature insulation wool in high temperature applications have strongly increased during the last five years. Especially the production capacities of polycrystalline wool (aluminium oxide wool e.g. Altra B72) have been doubled within the last three years. Primarily ultra light weight products made from HTIW are used in industrial furnaces with application temperatures above 1000 C and / or with high thermo-mechanical (thermal shock) and chemical exposure. The outstanding and essential advantages of these materials are obviously: Ultra light weight material with high resilience and flexibility, Optimised energy consumption (energy saving up to 50% compared

Predicting tensile strength of friction stir welded AA6061 aluminium alloy joints by a mathematical model

International Nuclear Information System (INIS)

Elangovan, K.; Balasubramanian, V.; Babu, S.

2009-01-01

AA6061 aluminium alloy (Al-Mg-Si alloy) has gathered wide acceptance in the fabrication of light weight structures requiring a high strength-to weight ratio and good corrosion resistance. Compared to the fusion welding processes that are routinely used for joining structural aluminium alloys, friction stir welding (FSW) process is an emerging solid state joining process in which the material that is being welded does not melt and recast. This process uses a non-consumable tool to generate frictional heat in the abutting surfaces. The welding parameters such as tool rotational speed, welding speed, axial force etc., and tool pin profile play a major role in deciding the joint strength. An attempt has been made to develop a mathematical model to predict tensile strength of the friction stir welded AA6061 aluminium alloy by incorporating FSW process parameters. Four factors, five levels central composite design has been used to minimize number of experimental conditions. Response surface method (RSM) has been used to develop the model. Statistical tools such as analysis of variance (ANOVA), student's t-test, correlation co-efficient etc. have been used to validate the developed model. The developed mathematical model can be effectively used to predict the tensile strength of FSW joints at 95% confidence level

PERFORMANCE EVALUATION OF A LIGHT-WEIGHT MULTI-ECHO LIDAR FOR UNMANNED ROTORCRAFT APPLICATIONS

Directory of Open Access Journals (Sweden)

G. Conte

2013-08-01

Full Text Available The paper presents a light-weight and low-cost airborne terrain mapping system. The developed Airborne LiDAR Scanner (ALS system consists of a high-precision GNSS receiver, an inertial measurement unit and a magnetic compass which are used to complement a LiDAR sensor in order to compute a digital surface model. Evaluation of the accuracy of the generated surface model is presented. Additionally, a comparison is provided between the surface model generated from the developed ALS system and a model generated using a commercial photogrammetric software. Finally, the multi-echo capability of the used LiDAR sensor is evaluated in areas covered with dense vegetation. The ALS system and camera systems were mounted on-board an industrial unmanned helicopter of around 100 kilograms maximum take-off weight. Presented results are based on real flight-test data.

Light weight radioisotope heater unit (LWRHU): a technical description of the reference design

International Nuclear Information System (INIS)

Tate, R.E.

1982-01-01

The Light Weight Radioisotope Heater Unit (LWRHU), a new radioisotope heater unit for use in space missions, is a 238 PuO 2 -fueled unit designed to provide a thermal watt in dispersed locations on a spacecraft. The LWRHU is required to maintain the temperature of a component at a level where the component will function reliably in space. Two major constraints are placed on the unit's design; it must be as light as possible and must provide enough protection to immobilize the plutonium fuel to the maximum extent in all phases of the unit's lifetime. The four components are pelletized fuel, platinum-alloy encapsulation, pyrolytic graphite thermal insulation, and high-technology graphite ablation shell. The LWRHU is a cylinder 32 mm (1.26 in.) high and 26 mm (1.02 in.) in diameter. It weighs slightly less than 40 g

Advanced high strength steels for automotive industry

Directory of Open Access Journals (Sweden)

Galán, J.

2012-04-01

Full Text Available The car industry is facing pressure because of the growing demand for more fuel-efficient passenger cars. In order to limit energy consumption and air pollution the weight of the carbody has to be reduced. At the same time, high levels of safety have to be guaranteed. In this situation, the choice of material becomes a key decision in car design. As a response to the requirements of the automotive sector, high strength steels and advanced high strength steels have been developed by the steel industry. These modern steel grades offer an excellent balance of low cost, light weight and mechanical properties.

La industria del automóvil se enfrenta a una creciente demanda de vehículos de pasajeros más eficientes. Con el fin de disminuir el consumo de energía y la contaminación ambiental, el peso del vehículo tiene que ser reducido, al mismo tiempo que se garantizan altos niveles de seguridad. Ante esta situación, la elección de material se convierte en una decisión crucial en el diseño del vehículo. Como respuesta a las necesidades del sector automovilístico, nuevos aceros avanzados y de alta resistencia, han sido desarrollados por la industria siderúrgica. Dichos tipos de acero ofrecen un excelente equilibrio de precio, peso y propiedades mecánicas.

А new factor effecting gel strength of pectin polysaccharides

Directory of Open Access Journals (Sweden)

S. E. Kholov

2016-01-01

Full Text Available Pectin polysaccharides obtained from various raw materials have a different component composition and form gels with water, sugar and acid or calcium. In this study, an experimental approach the gelation properties of different pectin samples, varied from different sources, using new methods of hydrolysis and purification. Samples were obtained by hydrolysis of accelerated extraction of pectin and purified by diaultrfiltration, have a high gel strength. The highest gel strength have been found in series of high methoxyl (HM- pectin samples of apple, peach, orange and low methoxyl (LM- pectin samples of commercial citrus pectin and apple pectin obtained by new method. It is shown that in addition to the basic parameters (the content of galacturonic acid, degree of esterification, molecular weight and hidrodinamic radius macromolecule to affect gel strength pectins aggregation of macromolecules, which is determined by the z-average molecular weight. There were observed a clear pattern of the influence of the molecular weight on hydrodynamic parameters for both HM- and LM- pectin samples on the gel strength. It were shown that a high values of molecular weight, intrinsic viscosity, and radius of gyration of pectin samples can significantly increase gel strength, while the value of Mz oppositely influenced the gel strength. As a result, a systematic analysis of this parameter and its relationship to the average molecular weight found that indeed the ratio Mz/Mw for pectin’s is an crucial to assess the quality of pectin at the study of gel strength for pectin polysaccharides.

A High Resolution, Light-Weight, Synthetic Aperture Radar for UAV Application

International Nuclear Information System (INIS)

Doerry, A.W.; Hensley, W.H.; Stence, J.; Tsunoda, S.I.; Pace, F.; Walker, B.C.; Woodring, M.

1999-06-01

(U) Sandia National Laboratories in collaboration with General Atomics (GA) has designed and built a high resolution, light-weight, Ku-band Synthetic Aperture Radar (SAR) known as ''Lynx''. Although Lynx can be operated on a wide variety of manned and unmanned platforms, its design is optimized for use on medium altitude Unmanned Aerial Vehicles (UAVS). In particular, it can be operated on the Predator, I-GNAT, and Prowler II platforms manufactured by GA. (U) The radar production weight is less than 120 lb and operates within a 3 GHz band from 15.2 GHz to 18.2 GHz with a peak output power of 320 W. Operating range is resolution and mode dependent but can exceed 45 km in adverse weather (4 mm/hr rain). Lynx has operator selectable resolution and is capable of 0.1 m resolution in spotlight mode and 0.3 m resolution in strip map mode, over substantial depression angles (5 to 60 deg) and squint angles (broadside and ±45 deg). Real-time Motion Compensation is implemented to allow high-quality image formation even during vehicle turns and other maneuvers

Application of the weighted total field-scattering field technique to 3D-PSTD light scattering model

Science.gov (United States)

Hu, Shuai; Gao, Taichang; Liu, Lei; Li, Hao; Chen, Ming; Yang, Bo

2018-04-01

PSTD (Pseudo Spectral Time Domain) is an excellent model for the light scattering simulation of nonspherical aerosol particles. However, due to the particularity of its discretization form of the Maxwell's equations, the traditional Total Field/Scattering Field (TF/SF) technique for FDTD (Finite Differential Time Domain) is not applicable to PSTD, and the time-consuming pure scattering field technique is mainly applied to introduce the incident wave. To this end, the weighted TF/SF technique proposed by X. Gao is generalized and applied to the 3D-PSTD scattering model. Using this technique, the incident light can be effectively introduced by modifying the electromagnetic components in an inserted connecting region between the total field and the scattering field region with incident terms, where the incident terms are obtained by weighting the incident field by a window function. To optimally determine the thickness of connection region and the window function type for PSTD calculations, their influence on the modeling accuracy is firstly analyzed. To further verify the effectiveness and advantages of the weighted TF/SF technique, the improved PSTD model is validated against the PSTD model equipped with pure scattering field technique in both calculation accuracy and efficiency. The results show that, the performance of PSTD seems to be not sensitive to variation of window functions. The number of the connection layer required decreases with the increasing of spatial resolution, where for spatial resolution of 24 grids per wavelength, a 6-layer region is thick enough. The scattering phase matrices and integral scattering parameters obtained by the improved PSTD show an excellent consistency with those well-tested models for spherical and nonspherical particles, illustrating that the weighted TF/SF technique can introduce the incident precisely. The weighted TF/SF technique shows higher computational efficiency than pure scattering technique.

Relationship between hamstring length and gluteus maximus strength with and without normalization.

Science.gov (United States)

Lee, Dong-Kyu; Oh, Jae-Seop

2018-01-01

[Purpose] This study assessed the relationship between hamstring length and gluteus maximus (GM) strength with and without normalization by body weight and height. [Subjects and Methods] In total, 34 healthy male subjects volunteered for this study. To measure GM strength, subjects performed maximal hip joint extension with the knee joints flexed to 90° in the prone position. GM strength was normalized for body weight and height. [Results] GM strength with normalization was positively correlated with hamstring length, whereas GM strength without normalization was negatively correlated with hamstring length. [Conclusion] The normalization of GM strength by body weight and height has the potential to lead to more appropriate conclusions and interpretations about its correlation with hamstring length. Hamstring length may be related to GM strength.

Strength resistance test of superior members for elderly people: comparison between dumbbells with different weights

Directory of Open Access Journals (Sweden)

Lucélia Justino Borges

2008-07-01

Full Text Available http://dx.doi.org/10.5007/1980-0037.2008v10n3p261 The aim of the study was to compare the performance of elderly people in the strength resistance test of superior members (SRTSM with dumbbells of different weights (1,8 kg and 2 kg for women and 3,6 kg and 4 kg for men. The sample consisted of 407 elderly (349 feminine and 58 masculine, with age of 60 to 88 years, practitioners of physical exercise for at least six months. The used instrument was the SRTSM of the battery of tests American Alliance for Health, Physical Education, Recreation and Dance (AAHPERD. Two executions of the test were carried through with dumbbells of different weights, SRTSM (1,8 kg and 3,6 kg and “adjusted” SRTSM (2 kg and 4 kg. For the analysis of the data, it was proceeded descriptive analysis, test t of Student for independent samples, paired t test for dependent samples and ANOVA with post-hoc of Tukey, adopting itself the 5% level significance. The results demonstrated that the use of dumbbells with 4 weights of 2 and kg, seem not to affect the performance of the elderly ones, mainly of the masculine sex. For the feminine sex significant difference in the averages of the second comparison carried through for the sort was detected. However, this difference can have been resulting from external factors to the test, since, the greater average obtained was for “the adjusted” SRTSM. Nevertheless, one tries to facilitate even more the evaluation of the functional capacity of the elderly population, being recommended for SRTSM the use of dumbbells with weight of 2 kg for women and 4kg for men that they are of low cost, easy acquisition and access in the Brazilian market.

The Effect of Lithium Disilicate Ceramic Thickness and Translucency on Shear Bond Strength of Light-cured Resin Cement

Directory of Open Access Journals (Sweden)

Mohammad Javad Moghaddas

2017-09-01

Full Text Available Introduction: To achieve acceptable clinical performance, a ceramic veneer must be bonded to enamel by well-polymerized resin cement. Among different factors, thickness and translucency of the ceramic may affect the resin cement polymerization. Thus, the current study evaluated the effect of the thickness and translucency of lithium disilicate ceramic on light-cured resin cement bond strength to enamel. Methods: In this laboratory study, 208 sound bovine incisors were equally divided into 16 groups (n = 13. The lithium disilicate ceramic cubes in four thicknesses (0.4, 0.6, 0.8 and 1 mm with four translucencies (high and medium opaque, high and low translucent were fabricated and bonded to prepared enamel surfaces using a light-cured translucent resin cement according to manufacturer recommendations. After 5000 cycles of thermocycling, the bonded specimens were placed in a universal testing machine and loaded to the point of fracture. To determine the mode of failure, each sample was observed under a stereomicroscope. Data were recorded and analyzed by Shapiro-Wilk test and two-way analysis of variance (ANOVA. Results: The ceramic thickness and translucency could not significantly affect shear bond strength (SBS of resin cement to enamel (p = 0.17 and p = 0.097, respectively.  The Adhesive and ceramic cohesive failures were reported as the maximum and minimum mode of failure, respectively. Conclusion: The SBS of the light-cured resin cement bonding to enamel and lithium disilicate ceramic was not affected by the translucency of ceramics having a thickness of less than 1 mm.

Grip Strength Survey Based on Hand Tool Usage

Directory of Open Access Journals (Sweden)

Erman ÇAKIT

2016-12-01

Full Text Available Hand grip strength is broadly used for performing tasks involving equipment in production and processing activities. Most professionals in this field rely on grip strength to perform their tasks. There were three main aims of this study: i determining various hand grip strength measurements for the group of hand tool users, ii investigating the effects of height, weight, age, hand dominance, body mass index, previous Cumulative Trauma Disorder (CTD diagnosis, and hand tool usage experience on hand grip strength, and iii comparing the obtained results with existing data for other populations. The study groups comprised 71 healthy male facility workers. The values of subjects’ ages was observed between 26 and 74 years. The data were statistically analyzed to assess the normality of data and the percentile values of grip strength. The results of this study demonstrate that there were no significance differences noted between dominant and non-dominant hands. However, there were highly significant differences between the CTD group and the other group. Hand grip strength for the dominant hand was positively correlated to height, weight, and body mass index, and negatively correlated to age and tool usage experience. Hand dominance, height, weight, body mass index, age and tool usage experience should be considered when establishing normal values for grip strength.

Effect of Annealing Temperature on the Microstructure, Tensile Properties, and Fracture Behavior of Cold-Rolled High-Mn Light-Weight Steels

Energy Technology Data Exchange (ETDEWEB)

Lee, Jae-Hyun; Cho, Kyung Mox [Pusan National University, Busan (Korea, Republic of); Park, Seong-Jun; Moon, Joonoh; Kang, Jun-Yun; Park, Jun-Young; Lee, Tae-Ho [Korea Institute of Materials Science, Changwon (Korea, Republic of)

2017-05-15

The effects of the annealing temperature on the microstructure and tensile properties of cold-rolled light-weight steels are investigated using two Fe-30Mn-xAl-0.9C alloys that contain different Al content. The initial alloy microstructure is composed of a single austenite or a mixture of austenite and ferrite depending on the nominal aluminum content. For the alloy with 9 wt%Al content, the recrystallization and grain growth of austenite occurrs depending on the annealing temperature. However, for the alloy with 11 wt%Al content, the β-Mn phase is observed after annealing for 10 min at 550~800 ℃. The β-Mn transformation kinetics is the fastest at 700 ℃. The formation of the β-Mn phase has a detrimental effect on the ductility, and this leads to significant decreases in the total elongation. The same alloy also forms κ-carbide and DO3 ordering at 550~900 ℃. The investigated alloys exhibit a fully recrystallized microstructure after annealing at 900 ℃ for 10 min, which results in a high total elongation of 25~55%with a high tensile strength of 900~1170 MPa.

Preserving Healthy Muscle during Weight Loss123

Science.gov (United States)

Cava, Edda; Yeat, Nai Chien; Mittendorfer, Bettina

2017-01-01

Weight loss is the cornerstone of therapy for people with obesity because it can ameliorate or completely resolve the metabolic risk factors for diabetes, coronary artery disease, and obesity-associated cancers. The potential health benefits of diet-induced weight loss are thought to be compromised by the weight-loss–associated loss of lean body mass, which could increase the risk of sarcopenia (low muscle mass and impaired muscle function). The objective of this review is to provide an overview of what is known about weight-loss–induced muscle loss and its implications for overall physical function (e.g., ability to lift items, walk, and climb stairs). The currently available data in the literature show the following: 1) compared with persons with normal weight, those with obesity have more muscle mass but poor muscle quality; 2) diet-induced weight loss reduces muscle mass without adversely affecting muscle strength; 3) weight loss improves global physical function, most likely because of reduced fat mass; 4) high protein intake helps preserve lean body and muscle mass during weight loss but does not improve muscle strength and could have adverse effects on metabolic function; 5) both endurance- and resistance-type exercise help preserve muscle mass during weight loss, and resistance-type exercise also improves muscle strength. We therefore conclude that weight-loss therapy, including a hypocaloric diet with adequate (but not excessive) protein intake and increased physical activity (particularly resistance-type exercise), should be promoted to maintain muscle mass and improve muscle strength and physical function in persons with obesity. PMID:28507015

A Conceptual Design of Light-weighted Mobile Robot for the Integrity of SG Tubes in NPP

Energy Technology Data Exchange (ETDEWEB)

Seo, Yong Chil; Jeong, Kyung Min; Shin, Ho Chul; Lee, Sung Uk; Cho, Jae Wan; Choi, Young Soo; Kim, Seung Ho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Shin, Chun Sup; Park, Ki Tae [Korea Plant Serviceand Engineering, Busan (Korea, Republic of)

2010-10-15

Steam generators (SG) are among the most critical components of pressurized water Nuclear Power Plants (NPP). SG tubes must provide a reliable pressure boundary between the primary and secondary cooling water. It is because that any leakage from tube defects could result in the release of radioactivity to the environment. Thus degradations of steam generators tubes should be monitored and inspected periodically under nuclear regulatory. In-service inspections of SG tubes are carried out using eddy current test (ECT) and the defected tubes are usually plugged. Because the radioactivity in the internal of SG chambers limits free access of human worker, remote manipulators are required. In South Korea, Manipulators such as the Zetec SM series and the Westinghouse ROSA series have been used. Such manipulators are rigidly mounted to manways or tube sheets of SG. Confusions for the inspected tubes may occur from deflection of the manipulators. To reduce the deflections of the manipulators for covering the large working areas of tube sheets, sufficient rigidity is required and it leads to the increase of the weight. Such weight increase results in some difficulties for handling and more radiation exposure of human workers. Recently light-weighed mobile robots have been introduced by Westinghouse and Zetec. The robots can move keeping in contact with the tube sheets using devices which are commonly called cam-locks. They are easier to handle and provide no confusion for the position of the inspected tubes. But when the clamping forces are loosed accidently, they can be fall down and light repair works can be performed. This paper provides the design results for a light weighted mobile robot which is recently being developed in cooperation of our institutes

A Conceptual Design of Light-weighted Mobile Robot for the Integrity of SG Tubes in NPP

International Nuclear Information System (INIS)

Seo, Yong Chil; Jeong, Kyung Min; Shin, Ho Chul; Lee, Sung Uk; Cho, Jae Wan; Choi, Young Soo; Kim, Seung Ho; Shin, Chun Sup; Park, Ki Tae

2010-01-01

Steam generators (SG) are among the most critical components of pressurized water Nuclear Power Plants (NPP). SG tubes must provide a reliable pressure boundary between the primary and secondary cooling water. It is because that any leakage from tube defects could result in the release of radioactivity to the environment. Thus degradations of steam generators tubes should be monitored and inspected periodically under nuclear regulatory. In-service inspections of SG tubes are carried out using eddy current test (ECT) and the defected tubes are usually plugged. Because the radioactivity in the internal of SG chambers limits free access of human worker, remote manipulators are required. In South Korea, Manipulators such as the Zetec SM series and the Westinghouse ROSA series have been used. Such manipulators are rigidly mounted to manways or tube sheets of SG. Confusions for the inspected tubes may occur from deflection of the manipulators. To reduce the deflections of the manipulators for covering the large working areas of tube sheets, sufficient rigidity is required and it leads to the increase of the weight. Such weight increase results in some difficulties for handling and more radiation exposure of human workers. Recently light-weighed mobile robots have been introduced by Westinghouse and Zetec. The robots can move keeping in contact with the tube sheets using devices which are commonly called cam-locks. They are easier to handle and provide no confusion for the position of the inspected tubes. But when the clamping forces are loosed accidently, they can be fall down and light repair works can be performed. This paper provides the design results for a light weighted mobile robot which is recently being developed in cooperation of our institutes

40 CFR 86.1772-99 - Road load power, test weight, and inertia weight class determination.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 19 2010-07-01 2010-07-01 false Road load power, test weight, and inertia weight class determination. 86.1772-99 Section 86.1772-99 Protection of Environment ENVIRONMENTAL... for Light-Duty Vehicles and Light-Duty Trucks § 86.1772-99 Road load power, test weight, and inertia...

Process Simulation of Resistance Weld Bonding and Automotive Light-weight Materials

DEFF Research Database (Denmark)

Zhang, Wenqi; Chergui, Azeddine; Nielsen, Chris Valentin

of mechanical, electrical, thermal and metallurgical processes, which are essential for simulation of resistance welding process to predict the welding results and evaluate the weldability of materials. These functions have been further extended with new functions for optimization of welding process parameters...... and predicting welding process window, for weld planning with optimal welding parameter settings, and for modeling microstructures and hardness distribution after welding. Latest developments have been made on simulation of resistance welding with nonconductive materials for applications in weld bonding......This paper presents the latest developments in numerical simulation of resistance welding especially with the new functions for simulation of microstructures, weld bonding and spot welding of new light-weight materials. The fundamental functions in SORPAS® are built on coupled modeling...

EOSCOR: a light weight, microprocessor controlled solar neutron detector

International Nuclear Information System (INIS)

Koga, R.; Albats, P.; Frye, G.M. Jr.; Schindler, S.M.; Denehy, B.V.; Hopper, V.D.; Mace, O.B.

1979-01-01

A light weight high energy neutron detector with vertical detection efficiency of 0.005 at 40 MeV and 1.4 m 2 sensitive area has been developed for long duration super-pressure balloon flight observations of solar neutrons and gamma rays. It consists of two sets of four plastic scintillator hodoscopes separated by a 1 m time-of-flight path to observe n-p, C(n,p), and C(n,d) interactions. The neutron interactions are separated from gamma ray events through TOF measurements. For a large flare, the signal from solar neutrons is expected to be an order of magnitude greater than that of the atmospheric background. The microprocessor controls the data acquisition, accumulation of histograms, and the encoding of data for the telemetry systems. A test flight of the detector was made with a zero-pressure balloon. The expected many-week duration of a super-pressure balloon flight would significantly increase the probability of observing 20-150 MeV neutrons from a medium or large flare. (Auth.)

Ergonomic Evaluation of Space Shuttle Light-Weight Seat Lever Position and Operation

Science.gov (United States)

Maida, J.; Rajulu, Sudhakar L.; Bond, Robert L. (Technical Monitor)

2000-01-01

During a Shuttle flight in the early part of 1999, one of the crewmembers was unable to operate the backrest lever for the light-weight seat in microgravity. It is essential that the crewmembers are able to adjust this back-rest lever, which is titled forward 2 degrees from vertical during launch and then moved backwards to 10 degrees aft of vertical upon reaching orbit. This adjustment is needed to cushion the crewmembers during an inadvertent crash landing situation. The original Shuttle seats, which had seat controls located on the front left and right sides of the seat, were replaced recently with the new light-weight seats. The controls for these new, seats were moved to the night side with one control at the front and the other at the back. While it was uncertain whether the problem encountered was unique to that crewmember or not it was clear to the personnel responsible for maintaining the Shuttle seats that not knowing the cause of the problem posed a safety concern for NASA. Hence the Anthropometry and Biomechanics Facility (ABF) of the Johnson Space Center was requested to perform an evaluation of the seat controls and provide NASA with appropriate recommendations on whether the seat lever positions and operations should be modified. The ABF designed an experiment to investigate the amount of pull force exerted by subjects, wearing an unpressurized or pressurized crew launch escape suit, when controls were placed in the front and back (on the right side) of the light-weight seat. Single-axis load cells were attached to the seat levers, which measured the maximum static pull forces that were exerted by the subjects. Twelve subjects, six male and six female, participated in this study. Each subject was asked to perform the pull test at least three times for each combination of lever position and suit pressure conditions. The results from this study showed that as a whole (or in general), the subjects were able to pull on the lever at the back position with

The influence of poly(acrylic) acid number average molecular weight and concentration in solution on the compressive fracture strength and modulus of a glass-ionomer restorative.

LENUS (Irish Health Repository)

Dowling, Adam H

2011-06-01

The aim was to investigate the influence of number average molecular weight and concentration of the poly(acrylic) acid (PAA) liquid constituent of a GI restorative on the compressive fracture strength (σ) and modulus (E).

Structural behaviour of super-light structures

DEFF Research Database (Denmark)

Bagger, Anne; Hertz, Kristian Dahl

2010-01-01

structural functions: it leads load to the skeleton, it stabilizes the compression members of the skeleton, and it redistributes loads that are not optimal for the skeleton shape. In this paper, FE analysis is used to investigated the behaviour of a series of SLS beams of concrete, under varying stiffness......A new structural concept, called Super-light Structures (SLS), has recently been invented and patented at the Technical University of Denmark. The basic concept of SLS is to construct a skeleton of a stiff and strong material, such as ordinary or high strength concrete, and stabilize this skeleton...... with a lighter and softer material, such as lightweight concrete. The combined use of stiff and light material in SLS results in structures of high stiffness and low weight. The applied technology and the advantages of SLS are elaborated upon in [1] in these proceedings. The present paper focuses...

High-strength uranium-0.8 weight percent titanium alloy penetrators

International Nuclear Information System (INIS)

Northcutt, W.G.

1978-09-01

Long-rod kinetic-energy penetrators, produced from a uranium-0.8 titanium (U-0.8 Ti) alloy, are normally water quenched from the gamma phase (approximately 800 0 C) and aged to the desired hardness and strength levels. High cooling rates from 800 0 C in U-0.8 Ti alloy cylindrical bodies larger than about 13 mm in diameter cause internal voids, while slower rates of cooling can produce material that is unresponsive to aging. For the present study, elimination of quenching voids was of paramount importance; therefore, a process including the quenching of plate was explored. Vacuum-induction-cast ingots were forged and rolled into plate and cut into blanks from which the penetrators were obtained. Quenched U-0.8 Ti alloy blanks were aged at 350 to 500 0 C to determine the treatment that would provide maximum tensile and impact strengths. Both tensile and impact strengths were maximized by aging in vacuum for six hours at 450 0 C

Vertically-aligned carbon nanotubes on aluminum as a light-weight positive electrode for lithium-polysulfide batteries.

Science.gov (United States)

Liatard, S; Benhamouda, K; Fournier, A; Ramos, R; Barchasz, C; Dijon, J

2015-05-04

A light-weight, high specific surface current collector made of vertically-aligned carbon nanotubes grown on an aluminum substrate was fabricated and studied as a positive electrode in a semi-liquid lithium/polysulfide battery. This simple system delivered stable capacities over 1000 mA h gS(-1) and 2 mA h cm(-2) with almost no capacity loss over 50 cycles.

Lightweight self-compacting concrete with light expanded clay aggregate (LECA

Directory of Open Access Journals (Sweden)

Heiza Khaled

2018-01-01

Full Text Available Lightweight concretes have been successfully applied in building constructions for many years due to their favorable material properties, particularly their low specific weight in connection with a high strength, a high capability of thermal insulation and a high durability. The development leading to lightweight self-compacting concrete (LWSCC represents an important advanced step within the recent years. This concrete combines the favorable properties of a lightweight concrete with those of a self-compacting concrete. Research work is aimed on development of (LWSCC with the use of light aggregates “Light expanded clay aggregate (LECA”. In this research, first by specific gravity factor method, twenty different mix designs of (LWSCC were cast and tested to find out the values of slump flow, J-ring , V-funnel and 28 day compressive strength. Based on the results obtained, the best mix design was selected for further investigation. This paper also focuses on studying the effect of changing the reinforcement ratio on reinforced two way slabs when the dimensions were kept constant.

Study on reactor building structure using ultrahigh strength materials - Part 9: Summary of the study

International Nuclear Information System (INIS)

Tanaka, H.; Odajima, M.; Irino, K.; Hashiba, T.

1993-01-01

Considerations for longevity of nuclear facilities and ease of decommissioning are of great importance for future nuclear power plants. To this end, a concept of an optimal structural concept for nuclear reactor buildings has been studied: the main feature of this concept is to utilize large-sized, light weight prefabricated members with ultrahigh strength materials. The following two items have been selected to study the prospective structure: (1) Applicability of ultrahigh strength materials for reinforced concrete shear walls (2) Construction using large sized prefabricated members As the first step (1), material and structural tests using ultrahigh strength materials, and the subsequent analysis of those tests for reinforced concrete shear walls, has been conducted. The positive results of this study show a bright future for the use of ultrahigh strength materials for the reinforced concrete shear walls of nuclear reactor buildings. As the second step (2), tests on a mixed structure with precasted members have been conducted. Our results positively suggest the use of these materials and methods to improve prospective nuclear power plants. (author)

Design and strength evaluation of structural joint made by electro-magnetic forming (EMF)

International Nuclear Information System (INIS)

Park, Young-Bae; Oh, Soo-Ik; Kim, Heon-Young

2004-01-01

Recently, weight reduction of vehicles has been of great interest, and consequently, the use of low-density materials in the automotive industry is increasing every year. Materials should not be substituted such a way that material of component parts is simply changed because there is a problem in achieving stiffness and strength. To achieve these requirements, the automobile should be redesigned totally. Aluminum spaceframe is rapidly being adopted as a body structure for accommodating lightness, stiffness and strength requirement. In aluminum spaceframe manufacturing, it is often required to join aluminum tube. But there are few suitable methods for joining aluminum tube, so that much interest has been focused on testing suitable joining methods. Joining by electromagnetic forming(EMF) can be useful method in joining aluminum tube, which offers some advantages compared with the conventional joining method. In this paper, joining by EMF was investigated as a pre-study for applying an automotive spaceframe. Finite element simulations and strength tests were performed to analyze the influence of geometric parameters on joint strength. Based on these results, configurations of axial joint and torque joint were suggested and guidelines for designing EMF joint were established

Effects of supplementary lighting by natural light for growth of Brassica chinensis

Science.gov (United States)

Yeh, Shih-Chuan; Lee, Hui-Ping; Kao, Shih-Tse; Lu, Ju-Lin

2016-04-01

This paper present a model of cultivated chamber with supplementary natural colour light. We investigate the effects of supplementary natural red light and natural blue light on growth of Brassica chinensis under natural white light illumination. After 4 weeks of supplementary colour light treatment, the experiment results shown that the weight of fresh leaf were not affected by supplementary natural blue light. However, those Brassica chinensis were cultivated in the chambers with supplementary natural red light obtained a significant increasing of fresh weight of leaf under both white light illuminate models. The combination of natural white light with supplementary natural red light illumination will be benefits in growth for cultivation and energy saving.

Evaluation of Impact Strength of Epoxy Based Hybrid Composites Reinforced with E-Glass/Kevlar 49

Directory of Open Access Journals (Sweden)

SUBHAN ALIJOGI

2017-10-01

Full Text Available In hybridization different fibers are stacked layer by layer to produce laminates have specific strength and stiffness and employed in light weight high strength applications. Physically mean fabricated hybrid composites used in aerospace, under water, body armors and armed forces establishment. In present work drop-weight impact response of hybrid composites were investigated by making laminates of hybrid composites. In Hybridization layers of E-glass (roving and Kevlar 49 fabrics stacked with epoxy resin. The layers formulation was set up by hand layup method. Impregnationsof epoxy resin of commercial grade (601A in fabrics were accomplished by VRTM (Vacuum Bagging Resin Transfer Molding technique. Layup placementof Glass fibers/ Kevlar at 0°/90°, 45°/45° and 30°/60° were set for this work. Mechanical properties such as impact strength, bear resistance and break resistance were analyzed by usingASTM D-256 and D-3763 standard.Experimental investigation was conducted using instrumented Dart impact and Izod Impact test. E-glass/Kevlar 49 at layup 0°/90°and 30°/60°exhibited improvedimpact strength than 45°/45°. The surface morphology and fractography were also investigated by capturing different images of Specimens by using the SEM (Scanning Electron Microscopy. The fiberreinforcement and matrix fracture were also observed by using SEM.The SEM images suggest that epoxy resin tightly bonded with Kevlar fibers whereas Glass fibers were pulled out from laminations.

Evaluation of impact strength of epoxy based hybrid composites reinforced with e-glass/kevlar 49

International Nuclear Information System (INIS)

Jogi, S.A.; Memon, I.A.; Baloch, M.; Chandio, A.D.

2017-01-01

In hybridization different fibers are stacked layer by layer to produce laminates have specific strength and stiffness and employed in light weight high strength applications. Physically mean fabricated hybrid composites used in aerospace, under water, body armors and armed forces establishment. In present work drop-weight impact response of hybrid composites were investigated by making laminates of hybrid composites. In Hybridization layers of E-glass (roving) and Kevlar 49 fabrics stacked with epoxy resin. The layers formulation was set up by hand layup method. Impregnations of epoxy resin of commercial grade (601A) in fabrics were accomplished by VRTM (Vacuum Bagging Resin Transfer Molding) technique. Layup placementof Glass fibers/ Kevlar at 0 degree/90 degree, 45 degree/45 degree and 30 degree/60 degree were set for this work. Mechanical properties such as impact strength, bear resistance and break resistance were analyzed by using ASTM D-256 and D-3763 standard. Experimental investigation was conducted using instrumented Dart impact and Izod Impact test. E-glass/Kevlar 49 at layup 0 degree/90 degree and 30 degree/60 degree exhibited improvedimpact strength than 45 degree/45 degree. The surface morphology and fractography were also investigated by capturing different images of Specimens by using the SEM (Scanning Electron Microscopy). The fiberreinforcement and matrix fracture were also observed by using SEM.The SEM images suggest that epoxy resin tightly bonded with Kevlar fibers whereas Glass fibers were pulled out from laminations. (author)

Water and saliva contamination effect on shear bond strength of brackets bonded with a moisture-tolerant light cure system.

Science.gov (United States)

Vicente, Ascensión; Mena, Ana; Ortiz, Antonio José; Bravo, Luis Alberto

2009-01-01

To evaluate the effects of water and saliva contamination on shear bond strength of brackets bonded with a moisture-tolerant light cure system. Brackets were bonded to 240 bovine lower incisors divided into 12 groups. Four bonding procedures were evaluated, including (1) TSEP/Transbond XT, (2) TMIP/ Transbond XT, (3) TSEP/Transbond PLUS, and (4) TMIP/Transbond PLUS, each under three different bonding conditions: without contamination, with water contamination, and with saliva contamination. Shear bond strength was measured with a universal testing machine. The adhesive remnant on the teeth was quantified with the use of image analyzing equipment. Without contamination, bond strengths for the four procedures were similar (P > .05). TSEP/Tranbond PLUS and TMIP/Transbond PLUS left significantly less adhesive on the teeth after debonding than TSEP/Transbond XT and TMIP/Transbond XT (P .017), although for TMIP/ Transbond XT, both variables showed significant reductions after contamination (P < .017). TSEP/Transbond PLUS, TMIP/Transbond PLUS, and TSEP/Transbond XT showed greater tolerance to wet conditions than was shown by TMIP/Transbond XT.

Report on achievements in fiscal 1999 on the project for development of an energy use rationalizing technology. Development of a basic technology to design and fabricate an innovative light-weight structure; 1999 nendo kakushinteki keiryo kozo sekkei seizo kiban gijutsu kaihatsu seika hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

This paper describes the achievements in fiscal 1999 on development of a basic technology to design and fabricate an innovative light-weight structure. Taking CFRP and aluminum alloy having excellent specific strength as the main object materials, weight reduction and reliability enhancement in aircraft structure are intended, while reducing largely the number of parts. In particular, the wings, the nose and the leading edge construction of civilian aircraft are of the structure assembled with a large number of parts, and are suitable as the research objects. A new conception will be introduced that structural members are fabricated by utilizing the characteristics of integrally formed CFRP, which will be assembled into a whole structure. Large structural metallic members currently used have such drawbacks as the use of great number of parts, complexity in manufacturing processes, low reliability, weight increase and corrosion due to rivet jointing. In order to solve these problems, development will be made on technologies for thin-wall large-size precision casting, and high-accuracy high-quality welding. To combine different kinds of members, and optimize strength, weight and economic performance of the entire structure, high-efficiency integration technologies will be discussed, and prototype full-size structure will be fabricated. The current fiscal year has started up the technology committee and its operation, analyzed technological problems in the entire structure, and established the action programs. An investigation was performed on the technological trends in overseas countries. (NEDO)

Development of a light weighted mobile robot for SG tube inspection in NPP

International Nuclear Information System (INIS)

Seo, Yong Chil; Jeong, Kyung Min; Shin, Hochul; Gweng, Jung Ju; Lee, Sung Uk; Jeong, Seung Ho; Choi, Young Soo; Kim, Seung Ho; Shin, Chun Sup; Park, Ki Tae

2012-01-01

Steam generators (SG) are among the most critical components of pressurized water Nuclear Power Plants (NPP). SG tubes must provide a reliable pressure boundary between the primary and secondary cooling water, because any leakage from tube defects could result in the release of radioactivity to the environment. Thus degradations of steam generators tubes should be monitored and inspected periodically under nuclear regulation. In service inspections of SG tubes are carried out using eddy current test (ECT) and the defected tubes are usually plugged. Because the radioactivity in the internal SG chambers limits free access of human workers, remote manipulators are required. In South Korea, Manipulators such as the Zet ec SM series and the Westinghouse ROSA series have bee used. Such manipulators are rigidly mounted to man ways or tube sheets of SG. Confusions of the inspected tubes may occur from deflection of the manipulators. To reduce the deflections of the manipulators for covering the large working areas of tube sheets, sufficient rigidity is required and that leads to an increase of the weight. Such weight increase results in some difficulties for handling and more radiation exposure of human workers. Recently light weighed mobile robots have been introduced by Westinghouse and Zet ec. The robots can move keeping in contact with the tube sheets using devices which are commonly called cam locks. They are easier to handle and provide no confusion for the position of the inspected tubes. But when the clamping forces are loosed accidentally, they can be fall down and light repair works can be performed. This paper provides the design results for a lightweight mobile robot which is being developed in cooperation of our institutes

Development of a light weighted mobile robot for SG tube inspection in NPP

Energy Technology Data Exchange (ETDEWEB)

Seo, Yong Chil; Jeong, Kyung Min; Shin, Hochul; Gweng, Jung Ju; Lee, Sung Uk; Jeong, Seung Ho; Choi, Young Soo; Kim, Seung Ho [KAERI, Daejeon (Korea, Republic of); Shin, Chun Sup; Park, Ki Tae [Korea Plant Service and Engineering, Busan (Korea, Republic of)

2012-10-15

Steam generators (SG) are among the most critical components of pressurized water Nuclear Power Plants (NPP). SG tubes must provide a reliable pressure boundary between the primary and secondary cooling water, because any leakage from tube defects could result in the release of radioactivity to the environment. Thus degradations of steam generators tubes should be monitored and inspected periodically under nuclear regulation. In service inspections of SG tubes are carried out using eddy current test (ECT) and the defected tubes are usually plugged. Because the radioactivity in the internal SG chambers limits free access of human workers, remote manipulators are required. In South Korea, Manipulators such as the Zet ec SM series and the Westinghouse ROSA series have bee used. Such manipulators are rigidly mounted to man ways or tube sheets of SG. Confusions of the inspected tubes may occur from deflection of the manipulators. To reduce the deflections of the manipulators for covering the large working areas of tube sheets, sufficient rigidity is required and that leads to an increase of the weight. Such weight increase results in some difficulties for handling and more radiation exposure of human workers. Recently light weighed mobile robots have been introduced by Westinghouse and Zet ec. The robots can move keeping in contact with the tube sheets using devices which are commonly called cam locks. They are easier to handle and provide no confusion for the position of the inspected tubes. But when the clamping forces are loosed accidentally, they can be fall down and light repair works can be performed. This paper provides the design results for a lightweight mobile robot which is being developed in cooperation of our institutes.

Setting Mechanical Properties of High Strength Steels for Rapid Hot Forming Processes

Science.gov (United States)

Löbbe, Christian; Hering, Oliver; Hiegemann, Lars; Tekkaya, A. Erman

2016-01-01

Hot stamping of sheet metal is an established method for the manufacturing of light weight products with tailored properties. However, the generally-applied continuous roller furnace manifests two crucial disadvantages: the overall process time is long and a local setting of mechanical properties is only feasible through special cooling techniques. Hot forming with rapid heating directly before shaping is a new approach, which not only reduces the thermal intervention in the zones of critical formability and requested properties, but also allows the processing of an advantageous microstructure characterized by less grain growth, additional fractions (e.g., retained austenite), and undissolved carbides. Since the austenitization and homogenization process is strongly dependent on the microstructure constitution, the general applicability for the process relevant parameters is unknown. Thus, different austenitization parameters are analyzed for the conventional high strength steels 22MnB5, Docol 1400M, and DP1000 in respect of the mechanical properties. In order to characterize the resulting microstructure, the light optical and scanning electron microscopy, micro and macro hardness measurements, and the X-ray diffraction are conducted subsequent to tensile tests. The investigation proves not only the feasibility to adjust the strength and ductility flexibly, unique microstructures are also observed and the governing mechanisms are clarified. PMID:28773354

Impact of low alcohol verbal descriptors on perceived strength: An experimental study.

Science.gov (United States)

Vasiljevic, Milica; Couturier, Dominique-Laurent; Marteau, Theresa M

2018-02-01

Low alcohol labels are a set of labels that carry descriptors such as 'low' or 'lighter' to denote alcohol content in beverages. There is growing interest from policymakers and producers in lower strength alcohol products. However, there is a lack of evidence on how the general population perceives verbal descriptors of strength. The present research examines consumers' perceptions of strength (% ABV) and appeal of alcohol products using low or high alcohol verbal descriptors. A within-subjects experimental study in which participants rated the strength and appeal of 18 terms denoting low (nine terms), high (eight terms) and regular (one term) strengths for either (1) wine or (2) beer according to drinking preference. Thousand six hundred adults (796 wine and 804 beer drinkers) sampled from a nationally representative UK panel. Low, Lower, Light, Lighter, and Reduced formed a cluster and were rated as denoting lower strength products than Regular, but higher strength than the cluster with intensifiers consisting of Extra Low, Super Low, Extra Light, and Super Light. Similar clustering in perceived strength was observed amongst the high verbal descriptors. Regular was the most appealing strength descriptor, with the low and high verbal descriptors using intensifiers rated least appealing. The perceived strength and appeal of alcohol products diminished the more the verbal descriptors implied a deviation from Regular. The implications of these findings are discussed in terms of policy implications for lower strength alcohol labelling and associated public health outcomes. Statement of contribution What is already known about this subject? Current UK and EU legislation limits the number of low strength verbal descriptors and the associated alcohol by volume (ABV) to 1.2% ABV and lower. There is growing interest from policymakers and producers to extend the range of lower strength alcohol products above the current cap of 1.2% ABV set out in national legislation. There

Weight reduction of vehicles and light metals; Jidosya no keryoka to keikinzoku zairyo

Energy Technology Data Exchange (ETDEWEB)

Manabe, Akira. [Toyota Motor Corp., Aichi (Japan). Component and System Development Center

1999-08-15

Weight reduction of vehicles (WRV) is a continuous challenge from the beginning of the vehicle history, however the purpose of WRV has been changing by social requirements. Recently automotive industry is facing is facing with the global warmin and the other environmental issues, so we are vast amount of R and D resources to improve the fuel economy. In this paper, the changes of the purpose of WRV and, the relation between fuel economy and WRV, are summarized. And also the current status of light metals usage and the future work for the related material issues, in particuar the corrosion resistance, are brifly mentioned. (author)

Comparison of the effects of weight loss from a high-protein versus standard-protein energy-restricted diet on strength and aerobic capacity in overweight and obese men.

Science.gov (United States)

Wycherley, Thomas P; Buckley, Jonathan D; Noakes, Manny; Clifton, Peter M; Brinkworth, Grant D

2013-02-01

To compare the effects of two low-fat, hypoenergetic diets differing in carbohydrate-to-protein ratio, on strength and aerobic capacity measures in overweight and obese men. In a parallel design, 56 men (age, 45.5 ± 8.7 years; BMI, 33.6 ± 3.9 kg/m(2)) were randomly assigned to a low-fat, energy-restricted diet (7,000 kJ/day) with either high protein (HP: protein/carbohydrate/fat % energy, 35:40:25) or standard protein (SP, 17:58:25). Body weight, body composition, muscle strength and aerobic capacity were assessed at baseline and after 12 weeks. Forty-two participants completed the study (HP, n = 21; SP, n = 21). Both groups experienced similar reductions in body weight (HP, -10.7 ± 5.3 kg [-9.8%]; SP, -8.7 ± 3.5 kg [-8.4%]) and fat-free mass (HP, -2.8 ± 3.6 kg; SP, -3.2 ± 2.7 kg; P 0.14 time × group interaction). There was a trend for a greater reduction in fat mass in the HP diet group, (-7.7 ± 4.3 kg [-21.2%] vs. -5.4 ± 3.3 kg [-15.1%]; P diet effect (P ≤ 0.23 time × group interaction). In overweight and obese men, both a HP and SP diet reduced body weight and improved body composition with similar effects on strength and aerobic capacity.

Maximal Strength Testing in Healthy Children.

Science.gov (United States)

Faigenbaum, Avery D.; Milliken, Laurie A.; Westcott, Wayne L.

2003-01-01

Evaluated the safety and efficacy of 1 repetition maximum (1RM) strength testing in healthy children age 6-12 years. Data were collected on 96 children who performed a 1RM test on one upper body and one lower body exercise using child-sized weight machines. Findings indicated that children could safely perform 1RM strength tests provided…

Obesity and the labor market: A fresh look at the weight penalty.

Science.gov (United States)

Caliendo, Marco; Gehrsitz, Markus

2016-12-01

This paper applies semiparametric regression models to shed light on the relationship between body weight and labor market outcomes in Germany. We find conclusive evidence that these relationships are poorly described by linear or quadratic OLS specifications. Women's wages and employment probabilities do not follow a linear relationship and are highest at a body weight far below the clinical threshold of obesity. This indicates that looks, rather than health, is the driving force behind the adverse labor market outcomes to which overweight women are subject. Further support is lent to this notion by the fact that wage penalties for overweight and obese women are only observable in white-collar occupations. On the other hand, bigger appears to be better in the case of men, for whom employment prospects increase with weight, albeit with diminishing returns. However, underweight men in blue-collar jobs earn lower wages because they lack the muscular strength required in such occupations. Copyright © 2016 Elsevier B.V. All rights reserved.

Weighted Evolving Networks with Self-organized Communities

International Nuclear Information System (INIS)

Xie Zhou; Wang Xiaofan; Li Xiang

2008-01-01

In order to describe the self-organization of communities in the evolution of weighted networks, we propose a new evolving model for weighted community-structured networks with the preferential mechanisms functioned in different levels according to community sizes and node strengths, respectively. Theoretical analyses and numerical simulations show that our model captures power-law distributions of community sizes, node strengths, and link weights, with tunable exponents of ν ≥ 1, γ > 2, and α > 2, respectively, sharing large clustering coefficients and scaling clustering spectra, and covering the range from disassortative networks to assortative networks. Finally, we apply our new model to the scientific co-authorship networks with both their weighted and unweighted datasets to verify its effectiveness

Extra Heat Loss Through Light Weight Roofs Due to Latent Heat

DEFF Research Database (Denmark)

Rode, Carsten

1996-01-01

that changes phase at the terminals of its passage.Note however, that convection of air most often will have an important effect on the overall heat flow - but that is a different topic.Macroscopic latent heat transferConsider the following scenario: Initially, moisture is present in its condensed or frozen......This report is one in a series of papers in Task 5 of IEA Annex 24 on how moisture and air movements affect the energy performance of building constructions. The effect of latent heat flow will be demonstrated by means of an example: a light weight flat roof.Latent heat flow is one of three...... processes by which moisture affects energy performance:Higher thermal conductivityMoist materials have higher thermal con-ductivity than when they are dry. This is because thermally conducting moisture replaces the better insulating air in the pores of the materials. Moisture also enhan-ces the thermal...

An Innovative Approach To Making Ultra Light Weight Wind Turbine Blades

Directory of Open Access Journals (Sweden)

Suhail Zaki Farooqui

2012-04-01

Full Text Available An innovative mould free method for the fabrication of ultimate light weight small wind turbine blades made out of composites has been suggested in this paper. The method has been practically applied with very satisfactory results. The method is low cost and is specifically suitable for individual small wind turbine makers. The airfoils used are simple to shape and possess good Cl/Cd characteristics. The blades are crafted using galvanized iron sheets, aluminum pipes, hard paper and fiberglass. A computer program is included with tip correction features to design the blades at the required power rating, wind speed, tip speed ratio and the chosen constant angle of attack. Results of the program run for designing 250 and 500 watt wind turbine blades at 8 m/s wind speed and tip speed ratios of 5.5 are tabulated. Performance results of the blades thus produced are also discussed.

Energy Saving Melting and Revert Reduction Technology (Energy-SMARRT): Light Metals Permanent Mold Casting

Energy Technology Data Exchange (ETDEWEB)

Fasoyinu, Yemi [CanmetMATERIALS

2014-03-31

Current vehicles use mostly ferrous components for structural applications. It is possible to reduce the weight of the vehicle by substituting these parts with those made from light metals such as aluminum and magnesium. Many alloys and manufacturing processes can be used to produce these light metal components and casting is known to be most economical. One of the high integrity casting processes is permanent mold casting which is the focus of this research report. Many aluminum alloy castings used in automotive applications are produced by the sand casting process. Also, aluminum-silicon (Al-Si) alloys are the most widely used alloy systems for automotive applications. It is possible that by using high strength aluminum alloys based on an aluminum-copper (Al-Cu) system and permanent mold casting, the performance of these components can be enhanced significantly. This will also help to further reduce the weight. However, many technological obstacles need to be overcome before using these alloys in automotive applications in an economical way. There is very limited information in the open literature on gravity and low-pressure permanent mold casting of high strength aluminum alloys. This report summarizes the results and issues encountered during the casting trials of high strength aluminum alloy 206.0 (Al-Cu alloy) and moderate strength alloy 535.0 (Al-Mg alloy). Five engineering components were cast by gravity tilt-pour or low pressure permanent mold casting processes at CanmetMATERIALS (CMAT) and two production foundries. The results of the casting trials show that high integrity engineering components can be produced successfully from both alloys if specific processing parameters are used. It was shown that a combination of melt processing and mold temperature is necessary for the elimination of hot tears in both alloys.

Effect of Curing Direction on Microtensile Bond Strength of Fifth and Sixth Generation Dental Adhesives

Directory of Open Access Journals (Sweden)

Ali Nadaf

2012-09-01

Full Text Available Background and Aims: Composite restorative materials and dental adhesives are usually cured with light sources. The light direction may influence the bond strength of dental adhesives. The aim of this study was to evaluate the effect of light direction on the microtensile bond strength of fifth and sixth generation dental adhesives.Materials and Methods: Prime & Bond NT and Clearfil SE bond were used with different light directions.Sixty human incisor teeth were divided into 4 groups (n=15. In groups A and C, Clearfil SE bond with light curing direction from buccal was used for bonding a composite resin to dentin. In groups B and D, Prime & Bond NT with light curing direction from composite was used. After thermocycling the specimens were subjected to tensile force until debonding occurred and values for microtensile bond strength were recorded. The data were analyzed using two-way ANOVA and Tukey post hoc test.Results: The findings showed that the bond strength of Clearfil SE bond was significantly higher than that of Prime&Bond NT (P<0.001. There was no significant difference between light curing directions (P=0.132.Conclusion: Light curing direction did not have significant effect on the bond strength. Sixth generation adhesives was more successful than fifth generation in terms of bond strength to dentin.

Shear strength characteristics of mechanically biologically treated municipal solid waste (MBT-MSW) from Bangalore

International Nuclear Information System (INIS)

Sivakumar Babu, G.L.; Lakshmikanthan, P.; Santhosh, L.G.

2015-01-01

Highlights: • Shear strength properties of mechanically biologically treated municipal solid waste. • Effect of unit weight and particle size on the shear strength of waste. • Effect of particle size on the strength properties. • Stiffness ratio and the strength ratio of MSW. - Abstract: Strength and stiffness properties of municipal solid waste (MSW) are important in landfill design. This paper presents the results of comprehensive testing of shear strength properties of mechanically biologically treated municipal solid waste (MBT-MSW) in laboratory. Changes in shear strength of MSW as a function of unit weight and particle size were investigated by performing laboratory studies on the MSW collected from Mavallipura landfill site in Bangalore. Direct shear tests, small scale and large scale consolidated undrained and drained triaxial tests were conducted on reconstituted compost reject MSW samples. The triaxial test results showed that the MSW samples exhibited a strain-hardening behaviour and the strength of MSW increased with increase in unit weight. Consolidated drained tests showed that the mobilized shear strength of the MSW increased by 40% for a unit weight increase from 7.3 kN/m 3 to 10.3 kN/m 3 at 20% strain levels. The mobilized cohesion and friction angle ranged from 5 to 9 kPa and 8° to 33° corresponding to a strain level of 20%. The consolidated undrained tests exhibited reduced friction angle values compared to the consolidated drained tests. The friction angle increased with increase in the unit weight from 8° to 55° in the consolidated undrained tests. Minor variations were found in the cohesion values. Relationships for strength and stiffness of MSW in terms of strength and stiffness ratios are developed and discussed. The stiffness ratio and the strength ratio of MSW were found to be 10 and 0.43

Shear strength characteristics of mechanically biologically treated municipal solid waste (MBT-MSW) from Bangalore

Energy Technology Data Exchange (ETDEWEB)

Sivakumar Babu, G.L., E-mail: gls@civil.iisc.ernet.in [Department of Civil Engineering, Indian Institute of Science, Bangalore 560012 (India); Lakshmikanthan, P., E-mail: lakshmikanthancp@gmail.com [Centre for Sustainable Technologies (CST), Indian Institute of Science, Bangalore 560012 (India); Santhosh, L.G., E-mail: lgsanthu2006@gmail.com [Centre for Sustainable Technologies (CST), Indian Institute of Science, Bangalore 560012 (India)

2015-05-15

Highlights: • Shear strength properties of mechanically biologically treated municipal solid waste. • Effect of unit weight and particle size on the shear strength of waste. • Effect of particle size on the strength properties. • Stiffness ratio and the strength ratio of MSW. - Abstract: Strength and stiffness properties of municipal solid waste (MSW) are important in landfill design. This paper presents the results of comprehensive testing of shear strength properties of mechanically biologically treated municipal solid waste (MBT-MSW) in laboratory. Changes in shear strength of MSW as a function of unit weight and particle size were investigated by performing laboratory studies on the MSW collected from Mavallipura landfill site in Bangalore. Direct shear tests, small scale and large scale consolidated undrained and drained triaxial tests were conducted on reconstituted compost reject MSW samples. The triaxial test results showed that the MSW samples exhibited a strain-hardening behaviour and the strength of MSW increased with increase in unit weight. Consolidated drained tests showed that the mobilized shear strength of the MSW increased by 40% for a unit weight increase from 7.3 kN/m{sup 3} to 10.3 kN/m{sup 3} at 20% strain levels. The mobilized cohesion and friction angle ranged from 5 to 9 kPa and 8° to 33° corresponding to a strain level of 20%. The consolidated undrained tests exhibited reduced friction angle values compared to the consolidated drained tests. The friction angle increased with increase in the unit weight from 8° to 55° in the consolidated undrained tests. Minor variations were found in the cohesion values. Relationships for strength and stiffness of MSW in terms of strength and stiffness ratios are developed and discussed. The stiffness ratio and the strength ratio of MSW were found to be 10 and 0.43.

In vitro analysis of shear bond strength and adhesive remnant index comparing light curing and self-curing composites

Directory of Open Access Journals (Sweden)

Murilo Gaby Neves

2013-06-01

Full Text Available OBJECTIVE: To evaluate, in vitro, the shear bond strength of self-curing (ConciseTM - 3M and Alpha Plast - DFL and light-curing composites (TransbondTM XT - 3M and Natural Ortho - DFL used in orthodontics bonding, associated to Morelli metal brackets, with further analysis of adhesive remnant index (ARI and enamel condition in scanning electron microscopy (SEM. METHODS: Forty human premolars, just extracted and stored in physiologic solution 0.9 % were used. Randomly, these samples were divided in four groups: G1 group, the brackets were bonded with ConciseTM - 3M composite; in G2 group, Alpha Plast - DFL composite was used; in G3 group, TransbondTM XT - 3M was used; in G4 group, Natural Ortho - DFL composite was used. These groups were submitted to shear strength tests in universal testing machine, at 0.5 mm per minute speed. RESULTS: Statistical difference between G3 and G4 groups was recorded, as G4 showing higher strength resistance than G3. In the other hand, there were no statistical differences between G1, G2 and G3 and G1, G2 and G4 groups. ARI analysis showed that there was no statistical difference between the groups, and low scores were recorded among then. The scanning electron microscopy (SEM analysis revealed the debonding spots and the enamel surface integrity. CONCLUSIONS: Shear bond strength was satisfactory and similar between the composites, however Natural Ortho - DFL revealed best comparing to TransbondTM XT - 3M.

Effect of pulsed current and post weld aging treatment on tensile properties of argon arc welded high strength aluminium alloy

International Nuclear Information System (INIS)

Balasubramanian, V.; Ravisankar, V.; Reddy, G. Madhusudhan

2007-01-01

This paper reveals the effect of pulsed current and post weld aging treatment on tensile properties of argon arc welded AA7075 aluminium alloy. This alloy has gathered wide acceptance in the fabrication of light weight structures requiring high strength-to-weight ratio, such as transportable bridge girders, military vehicles, road tankers and railway transport systems. The preferred welding processes of high strength aluminium alloy are frequently gas tungsten arc welding (GTAW) process and gas metal arc welding (GMAW) process due to their comparatively easier applicability and better economy. Weld fusion zones typically exhibit coarse columnar grains because of the prevailing thermal conditions during weld metal solidification. This often results inferior weld mechanical properties and poor resistance to hot cracking. In this investigation, an attempt has been made to refine the fusion zone grains by applying pulsed current welding technique. Four different welding techniques have been used to fabricate the joints and they are: (i) continuous current GTAW (CCGTAW), (ii) pulsed current GTAW (PCGTAW), (iii) continuous current GMAW (CCGMAW) and (iv) pulsed current GMAW (PCGMAW) processes. As welded joint strength is much lower than the base metal strength and hence, a simple aging treatment has been given to improve the tensile strength of the joints. Current pulsing leads to relatively finer and more equi-axed grain structure in GTA and GMA welds. In contrast, conventional continuous current welding resulted in predominantly columnar grain structures. Post weld aging treatment is accompanied by an increase in tensile strength and tensile ductility

Using OAI and other light-weight protocols to facilitate scholarly communication

CERN Multimedia

CERN. Geneva

2005-01-01

This presentation describes how we share and harvest sets of various OAI metadata, repurpose it through the Ockham Library Network, and demonstrate an alternative to traditional scholarly communication. The Ockham Library Network is a sponsored National Science Foundation Digital Library grant with co-PI's at Emory University, Virginia Tech, Oregon State University, and the University of Notre Dame. One of the purposes of Ockham is to exploit modular, light-weight protocols (such as OAI-PMH and SRW/U) into systems for learning, teaching, and scholarship. To date we have implemented a number of such services: * Ockham Digital Library Services Registry - A distributed directory of digital library services, collections, and agents. The contents of the Registry are described using the same XML schema articulated by the Information Environment Service Registry (IESR), and the records are shared among participating institutions on a peer-to-peer network utilizing OAI to propagate registry records amongst the distri...

Gradient Weight in Phonology

Science.gov (United States)

Ryan, Kevin Michael

2011-01-01

Research on syllable weight in generative phonology has focused almost exclusively on systems in which weight is treated as an ordinal hierarchy of clearly delineated categories (e.g. light and heavy). As I discuss, canonical weight-sensitive phenomena in phonology, including quantitative meter and quantity-sensitive stress, can also treat weight…

Body Temperature Controlled Optical and Thermal Information Storage Light Scattering Display with Fluorescence Effect and High Mechanical Strength.

Science.gov (United States)

Chen, Si; Tong, Xiaoqian; He, Huiwen; Ma, Meng; Shi, Yanqin; Wang, Xu

2017-04-05

A kind of body temperature controlled optical and thermal information storage light scattering display based on super strong liquid crystalline physical gel with special "loofah-like gel network" was successfully prepared. Such liquid crystal (LC) gel was obtained by mixing a dendritic gelator (POSS-G1-BOC), an azobenzene compound (2Azo2), and a phosphor tethered liquid crystalline host (5CB), which could show its best contrast ratio at around human body temperature under UV light because of the phosphor's fluorescence effect. The gel also has quite strong mechanical strength, which could be used in wearable device field especially under sunlight, even under the forcing conditions as harsh as being centrifuged for 10 min at the speed of 2000 r/min. The whole production process of such a display is quite simple and could lead to displays at any size through noncontact writing. We believe it will have wide applications in the future.

Weighted Scaling in Non-growth Random Networks

International Nuclear Information System (INIS)

Chen Guang; Yang Xuhua; Xu Xinli

2012-01-01

We propose a weighted model to explain the self-organizing formation of scale-free phenomenon in non-growth random networks. In this model, we use multiple-edges to represent the connections between vertices and define the weight of a multiple-edge as the total weights of all single-edges within it and the strength of a vertex as the sum of weights for those multiple-edges attached to it. The network evolves according to a vertex strength preferential selection mechanism. During the evolution process, the network always holds its total number of vertices and its total number of single-edges constantly. We show analytically and numerically that a network will form steady scale-free distributions with our model. The results show that a weighted non-growth random network can evolve into scale-free state. It is interesting that the network also obtains the character of an exponential edge weight distribution. Namely, coexistence of scale-free distribution and exponential distribution emerges.

Rapid Analysis of Apolar Low Molecular Weight Constituents in Wood Using High Pressure Liquid Chromatography with Evaporative Light Scattering Detection

NARCIS (Netherlands)

Claassen, F.W.; Haar, van de C.; Beek, van T.A.; Dorado, J.; Martinez-Inigo, M.; Sierra-Alvarez, R.

2000-01-01

A new high pressure liquid chromatographic method with evaporative light scattering detection was developed for the qualitative and quantitative analysis of apolar, low molecular weight constituents in wood. The wood extractives were obtained by means of a 6 h Soxhlet extraction with acetone. The

Weighted Scale-Free Network Properties of Ecological Network

International Nuclear Information System (INIS)

Lee, Jae Woo; Maeng, Seong Eun

2013-01-01

We investigate the scale-free network properties of the bipartite ecological network, in particular, the plant-pollinator network. In plant-pollinator network, the pollinators visit the plant to get the nectars. In contrast to the other complex network, the plant-pollinator network has not only the trophic relationships among the interacting partners but also the complexities of the coevolutionary effects. The interactions between the plant and pollinators are beneficial relations. The plant-pollinator network is a bipartite and weighted network. The networks have two types of the nodes: plant and pollinator. We consider the visiting frequency of a pollinator to a plant as the weighting value of the link. We defined the strength of a node as the sum of the weighting value of the links. We reported the cumulative distribution function (CDF) of the degree and the strength of the plant-pollinator network. The CDF of the plants followed stretched exponential functions for both degree and strength, but the CDF of the pollinators showed the power law for both degree and strength. The average strength of the links showed the nonlinear dependence on the degree of the networks.

Effect of programmed strength training on explosive strength of lower extremities in children aged 11 to 14 years

Directory of Open Access Journals (Sweden)

Atanasković Andrija

2014-01-01

Full Text Available Vertical jumps are an integral part of many sport activities. There are several factors that affect the athlete's jumping ability: strength, force and acceleration that occur when we jump. The jump is a complex and more articulated activity that requires not only strength, but great power as well. The main types of training to increase explosive strength are plyometric training and myogenic training with weight load on the lower extremities. The aim of this study was to determine the effect of myogenic training with weight load on explosive strength of the lower extremities. The first group is the control group (K, while the second group is an experimental group (E, each consisting of eighteen respondents. By Using the Myotest and performing the squat jump (SJ, the Height, Power, Force and Velocity were determined. The programme of power lasted for six weeks, twice a week for up to 60 minutes. We conclude that there is a statistically significant difference between the final and initial measurements in the experimental group, the multivariate level sig = 0.000. Increase in jump height ΔHeight = 3.28 in cm, force ΔForce = 4.68 in N/kg, the strength ΔPower = 6.18 in W/kg, the acceleration ΔVelocity = 21.8 in cm/s. The results of this study show that myogenic training with weight load has a positive impact on the explosive power of the lower extremities. This research was carried out against children aged 11 to 14 years, so we cannot say with certainty that this type of programme can have identical effects on athletes.

The importance of being light: aerodynamic forces and weight in ski jumping.

Science.gov (United States)

Schmölzer, B; Müller, W

2002-08-01

Many contemporary world class ski jumpers are alarmingly underweight and several cases of anorexia nervosa have come to light. Athletes strive for low body weight because it gives them a major competitive advantage. In order to stop this hazardous development, changes to the regulations are being discussed, and the International Ski Federation and the International Olympic Committee wish to be proactive in safe guarding the interest of the athletes and their health. This study of ski jumping uses field studies conducted during World Cup competitions, large-scale wind tunnel measurements with 1:1 models of ski jumpers in current equipment and highly accurate computer simulations of the flight phase that include the effects due to the athlete's position changes. Particular attention has been directed to the design of a reference jump that mirrors current flight style and equipment regulations (2001), and to the investigation of effects associated with variation in body mass, air density, and wind gusts during the simulated flight. The detailed analysis of the physics of ski jumping described here can be used for the investigation of all initial value and parameter variations that determine the flight path of a ski jumper and will form a reliable basis for setting regulations that will make it less attractive or even disadvantageous for the athlete to be extremely light.

A light weight secure image encryption scheme based on chaos & DNA computing

Directory of Open Access Journals (Sweden)

Bhaskar Mondal

2017-10-01

Full Text Available This paper proposed a new light weight secure cryptographic scheme for secure image communication. In this scheme the plain image is permuted first using a sequence of pseudo random number (PRN and encrypted by DeoxyriboNucleic Acid (DNA computation. Two PRN sequences are generated by a Pseudo Random Number Generator (PRNG based on cross coupled chaotic logistic map using two sets of keys. The first PRN sequence is used for permuting the plain image whereas the second PRN sequence is used for generating random DNA sequence. The number of rounds of permutation and encryption may be variable to increase security. The scheme is proposed for gray label images but the scheme may be extended for color images and text data. Simulation results exhibit that the proposed scheme can defy any kind of attack.

Effect of light intensity on ovarian gene expression, reproductive performance and body weight of rabbit does.

Science.gov (United States)

Sun, Liangzhan; Wu, Zhenyu; Li, Fuchang; Liu, Lei; Li, Jinglin; Zhang, Di; Sun, Chaoran

2017-08-01

The objective of the experiment was to find the minimum light intensity which could improve reproduction by examining its effect on ovarian gene expression, reproductive performance and body weight of rabbit does with three different light intensities: 60 (L), 80 (M), and 100 (H)lx. A total of 144 Rex-rabbits submitted to a 49-day reproductive regimen were used in this study. Ovaries were collected and relative abundance of mRNA for ovarian proteins of interest was examined with real-time PCR. Amount of protein for proteins of interest was examined by immunohistochemistry. Reproductive performance and doe bodyweight of the first three consecutive reproductive periods after initiation of the light intensity treatments were evaluated. The results provided evidence that light intensity had no effect on relative abundance of estradiol receptor-α (ER-α), follicle stimulating hormone receptor (FSHR), luteinizing hormone receptor (LHR), gonadotropin releasing hormone receptor 1 (GnRHR1) and progesterone receptor (PGR) mRNA. The relative abundance of growth hormone receptor (GHR) mRNA was, however, greater in Group L than M and H (Plight intensities (P>0.05). The bodyweight of the does in Group L was greater than the other two groups at first insemination, second insemination and the second postpartum period (P0.05). These observations suggest that light intensity between 60 and 100lx has no effect on the reproductive performance of rabbit does, however, the amounts of GHR mRNA and growth hormone (GH) protein were affected and the greater light intensity had a negative effect on bodyweight between the time of the first insemination and the second partum period. Copyright © 2017 Elsevier B.V. All rights reserved.

A study on the strength of an armour-grade aluminum under high strain-rate loading

Science.gov (United States)

Appleby-Thomas, G. J.; Hazell, P. J.

2010-06-01

The aluminum alloy 5083 in tempers such as H32 and H131 is an established light-weight armour material. While its dynamic response under high strain-rates has been investigated elsewhere, little account of the effect of material orientation has been made. In addition, little information on its strength under such loadings is available in the literature. Here, both the longitudinal and lateral components of stress have been measured using embedded manganin stress gauges during plate-impact experiments on samples with the rolling direction aligned both orthogonal and parallel to the impact axis. The Hugoniot elastic limit, spall, and shear strengths were investigated for incident pressures in the range 1-8 GPa, providing an insight into the response of this alloy under shock loading. Further, the time dependence of lateral stress behind the shock front was investigated to give an indication of material response.

Online weight training.

Science.gov (United States)

McNamara, John M; Swalm, Ricky L; Stearne, David J; Covassin, Tracey M

2008-07-01

The purpose of this study was to determine how a traditional weight training class compared to nontraditional classes that were heavily laden with technology. Could students learn resistance exercises by watching video demonstrations over the Internet? Three university weight training classes, each lasting 16 weeks, were compared. Each class had the same curriculum and workout requirements but different attendance requirements. The online group made extensive use of the Internet and was allowed to complete the workouts on their own at any gym that was convenient for them. Seventy-nine college-aged students were randomized into 3 groups: traditional (n = 27), hybrid (n = 25), and online (n = 27). They completed pretest and posttest measures on upper-body strength (i.e., bench press), lower-body strength (i.e., back squat), and knowledge (i.e., written exam). The results indicated that all 3 groups showed significant improvement in knowledge (p students to attend class and may have resulted in significantly lower scores on the bench press (p technology can be used in a weight training class. If this limit is exceeded, some type of monitoring system appears necessary to ensure that students are actually completing their workouts.

Design and Implementation of a Smart LED Lighting System Using a Self Adaptive Weighted Data Fusion Algorithm

Directory of Open Access Journals (Sweden)

Wen-Tsai Sung

2013-12-01

Full Text Available This work aims to develop a smart LED lighting system, which is remotely controlled by Android apps via handheld devices, e.g., smartphones, tablets, and so forth. The status of energy use is reflected by readings displayed on a handheld device, and it is treated as a criterion in the lighting mode design of a system. A multimeter, a wireless light dimmer, an IR learning remote module, etc. are connected to a server by means of RS 232/485 and a human computer interface on a touch screen. The wireless data communication is designed to operate in compliance with the ZigBee standard, and signal processing on sensed data is made through a self adaptive weighted data fusion algorithm. A low variation in data fusion together with a high stability is experimentally demonstrated in this work. The wireless light dimmer as well as the IR learning remote module can be instructed directly by command given on the human computer interface, and the reading on a multimeter can be displayed thereon via the server. This proposed smart LED lighting system can be remotely controlled and self learning mode can be enabled by a single handheld device via WiFi transmission. Hence, this proposal is validated as an approach to power monitoring for home appliances, and is demonstrated as a digital home network in consideration of energy efficiency.

Design and Implementation of a Smart LED Lighting System Using a Self Adaptive Weighted Data Fusion Algorithm

Science.gov (United States)

Sung, Wen-Tsai; Lin, Jia-Syun

2013-01-01

This work aims to develop a smart LED lighting system, which is remotely controlled by Android apps via handheld devices, e.g., smartphones, tablets, and so forth. The status of energy use is reflected by readings displayed on a handheld device, and it is treated as a criterion in the lighting mode design of a system. A multimeter, a wireless light dimmer, an IR learning remote module, etc. are connected to a server by means of RS 232/485 and a human computer interface on a touch screen. The wireless data communication is designed to operate in compliance with the ZigBee standard, and signal processing on sensed data is made through a self adaptive weighted data fusion algorithm. A low variation in data fusion together with a high stability is experimentally demonstrated in this work. The wireless light dimmer as well as the IR learning remote module can be instructed directly by command given on the human computer interface, and the reading on a multimeter can be displayed thereon via the server. This proposed smart LED lighting system can be remotely controlled and self learning mode can be enabled by a single handheld device via WiFi transmission. Hence, this proposal is validated as an approach to power monitoring for home appliances, and is demonstrated as a digital home network in consideration of energy efficiency.

Maximal isometric muscle strength values obtained By hand-held dynamometry in children between 6 and 15 years of age.

Science.gov (United States)

Escobar, Raul G; Munoz, Karin T; Dominguez, Angelica; Banados, Pamela; Bravo, Maria J

2017-01-01

In this study we aimed to determine the maximal isometric muscle strength of a healthy, normal-weight, pediatric population between 6 and 15 years of age using hand-held dynamometry to establish strength reference values. The secondary objective was determining the relationship between strength and anthropometric parameters. Four hundred normal-weight Chilean children, split into 10 age groups, separated by 1-year intervals, were evaluated. Each age group included between 35 and 55 children. The strength values increased with increasing age and weight, with a correlation of 0.83 for age and 0.82 for weight. The results were similar to those reported in previous studies regarding the relationships among strength, age, and anthropometric parameters, but the reported strength differed. These results provide normal strength parameters for healthy and normal-weight Chilean children between 6 and 15 years of age and highlight the relevance of ethnicity in defining reference values for muscle strength in a pediatric population. Muscle Nerve 55: 16-22, 2017. © 2016 Wiley Periodicals, Inc.

Influence of pre-pregnancy leisure time physical activity on gestational and postpartum weight gain and birth weight - a cohort study.

Science.gov (United States)

Hegaard, Hanne Kristine; Rode, Line; Katballe, Malene Kjær; Langberg, Henning; Ottesen, Bent; Damm, Peter

2017-08-01

In order to examine the association between pre-pregnancy leisure time physical activities and gestational weight gain, postpartum weight gain and birth weight, we analysed prospectively collected data from 1827 women with singleton term pregnancies. Women were categorised in groups of sedentary women, light exercisers, moderate exercisers and competitive athletes. The results showed that sedentary women on average gained 14.1 kg during pregnancy, whereas light exercisers gained 13.7 kg, moderate exercisers gained 14.3 kg and competitive athletes 16.1 kg. Competitive athletes had an increased risk of having a gestational weight gain above Institute of Medicine (IOM) recommendations with an odds ratio of 2.60 (1.32-5.15) compared to light exercisers. However, birth weight and one year postpartum weight was similar for all four groups. Thus, although competitive athletes gain more weight than recommended during pregnancy, this may not affect birth weight or postpartum weight. Impact statement What is already known on this subjectPrevious studies have found that increased pre-pregnancy physical activity is associated with lower gestational weight gain during the last trimester, but showed no association between the pre-pregnancy level of physical activity and mean birth weight. What the results of this study addWe found that women classified as competitive exercisers had a 2.6-fold increased risk of gaining more weight than recommended compared to light exercisers. Nearly 6 out of 10 women among the competitive exercisers gained more weight than recommended by IOM. Surprisingly, this did not appear to increase birth weight or post-partum weight gain, but other adverse effects cannot be excluded. What the implications are of these findings for clinical practice and/or further researchIn the clinical practice it may be relevant to focus on and advise pre-pregnancy competitive exercisers in order to prevent excessive gestational weight gain.

Low velocity impact behaviour of ultra high strength concrete panels

Indian Academy of Sciences (India)

Ultra high strength concrete; panel; drop weight test; impact analysis;. ABAQUS. 1. Introduction. Ultra high strength concrete ... Knight (2012) investigated the dynamic behaviour of steel fibre reinforced concrete plates under impact loading with ...

Augmenting Ordinal Methods of Attribute Weight Approximation

DEFF Research Database (Denmark)

Daneilson, Mats; Ekenberg, Love; He, Ying

2014-01-01

of the obstacles and methods for introducing so-called surrogate weights have proliferated in the form of ordinal ranking methods for criteria weights. Considering the decision quality, one main problem is that the input information allowed in ordinal methods is sometimes too restricted. At the same time, decision...... makers often possess more background information, for example, regarding the relative strengths of the criteria, and might want to use that. We propose combined methods for facilitating the elicitation process and show how this provides a way to use partial information from the strength of preference...

Heat treatment on keruing and light red meranti: The effect of heat exposure at different levels of temperature on bending strength properties

Science.gov (United States)

Noh, Nur Ilya Farhana Md; Ahmad, Zakiah

2017-11-01

Heat treatment on timbers is a process of applying heat to modify and equip the timbers with new improvised characteristics. It is environmental friendly compared to the common practice of treating timber by chemical preservatives. Malaysian hardwood timbers namely Keruing and Light Red Meranti which are in green condition were heat treated at temperature 150°C, 170°C, 190°C and 210°C, in a specially designed electronic furnace within one hour duration. The objectives were to determine the effect of heat treatment on bending strength properties of heat treated timbers in terms of Modulus of Elasticity (MOE) and Modulus of Rupture (MOR) and to examine the significance changes at each temperature level. Untreated samples for each species were used as a control sample. The results indicated that the bending strength properties for both species of timbers were affected by the heat exposure. Both MOE and MOR values for heat treated Keruing were increased when subjected to the temperature levels at 150°C, 170°C and 190°C except at 210°C. Heat treated Light Red Meranti shows the same pattern of increment on its MOE and MOR values after exposure to heat at three temperature levels applied and the values dropped at 210°C. However, for both of species, even though there were decrement occurred at 210°C, the value is still higher compared to the control sample. The increments of MOE and MOR values are an indicator that heat treatment had successfully improvised the bending strength properties of these two species of hardwood timber.

The Effect on Final Bond Strength of Bracket Manipulation Subsequent To Initial Positioning

Science.gov (United States)

Beebe, David A.

The shear bond strength of light activated orthodontic adhesives varies according to the composition of the material, placement protocol, and time prior to light curing. Manipulating brackets after their initial placement on a tooth can disrupt the adhesive's polymerization and compromise final bond strength. No previous research has investigated how a specific degree of manipulation, and the amount of time elapsed prior to curing, under specific lighting conditions, affects the orthodontic adhesives shear bond strength. Victory SeriesRTM, MBT prescription, premolar (3M Unitek, Monrovia, CA) orthodontic brackets were bonded using three different adhesives to sixty (60) bicuspids and varying the time after bracket manipulation before curing. The shear bond strength was calculated for each specimen. The brackets were debonded and the same teeth were rebonded with new, identical brackets, using the same protocol and under the same conditions. The results showed a statistically significant difference between the shear bond strength of Transbond XT and Grengloo, with Transbond XT having the highest strength. There was also a statistically significance difference in bond strength between the group cured 30 seconds after manipulation and the groups manipulated at different intervals prior to curing, with the 30 second group having the highest bond strength. This study confirms that various orthodontic adhesives have different bond strengths depending on manipulation and varying times prior to curing each adhesive.

Pressure vessels fabricated with high-strength wire and electroformed nickel

Science.gov (United States)

Roth, B.

1966-01-01

Metal pressure vessels of various shapes having high strength-to-weight ratios are fabricated by using known techniques of filament winding and electroforming. This eliminates nonuniform wall thickness and unequal wall strength which resulted from welding formed vessel segments together.

In healthy elderly postmenopausal women variations in BMD and BMC at various skeletal sites are associated with differences in weight and lean body mass rather than by variations in habitual physical activity, strength or VO2max.

Science.gov (United States)

Schöffl, I; Kemmler, W; Kladny, B; Vonstengel, S; Kalender, W A; Engelke, K

2008-01-01

The objective of this study was an integrated cross-sectional investigation for answering the question whether differences in bone mineral density in elderly postmenopausal women are associated with differences in habitual physical activity and unspecific exercise levels. Two hundred and ninety nine elderly women (69-/+3 years), without diseases or medication affecting bone metabolism were investigated. The influence of weight, body composition and physical activity on BMD was measured at multiple sites using different techniques (DXA, QCT, and QUS). Physical activity and exercise level were assessed by questionnaire, maximum strength of the legs and aerobic capacity. Variations in physical activity or habitual exercise had no effect on bone. The only significant univariate relation between strength/VO(2)max and BMD/BMC that remained after adjusting for confounding variables was between arm BMD (DXA) and hand-grip strength. The most important variable for explaining BMD was weight and for cortical BMC of the femur (QCT) lean body mass. Weight and lean body mass emerge as predominant predictors of BMD in normal elderly women, whereas the isolated effect of habitual physical activity, unspecific exercise participation, and muscle strength on bone parameters is negligible. Thus, an increase in the amount of habitual physical activity will probably have no beneficial impact on bone.

Effect of different thermo-light polymerization on flexural strength of two glass ionomer cements and a glass carbomer cement.

Science.gov (United States)

Gorseta, Kristina; Borzabadi-Farahani, Ali; Moshaverinia, Alireza; Glavina, Domagoj; Lynch, Edward

2017-07-01

Whether polymerization lights can be used for heating glass ionomer cements (GICs) or glass carbomer (GCP) to improve their mechanical properties is not well established. The purpose of this in vitro study was to assess the effect of thermo-light polymerization on the flexural strength (FS) of 2 GICs (Fuji IX GP Fast, Ketac Molar) and a GCP. Specimens (n=10) were prepared in stainless steel molds (2×2×25 mm), compressed, exposed to 3 polymerization lights (500, 1000, 1200 mW/cm 2 ) for 2 cycles of 40 seconds on each side, and stored in petroleum jelly (37°C, 24 hours). Significant FS differences were detected among groups after different thermo-light polymerization regimens (F=50.926, df=11, Pthermo-light polymerization with power outputs of 1000 (127.1 ±25.8 MPa) and 1200 mW/cm 2 (117.4 ±18.5 MPa), with no significance difference between them (P=.98), compared with 500 mW/cm 2 (24.1 ±1.7 MPa). For Ketac Molar, compared with autopolymerization setting (15.5 ±3.1 MPa), a significant increase in mean FS (∼2.5 times) was only observed in specimens treated with 1200 mW/cm 2 polymerization light (P=.03). For Fuji IX GP Fast, only the light with 1000 mW/cm 2 output significantly increased the FS (98.9 ±23.4 MPa, PThermo-light polymerization accelerated the development of FS in the tested GICs, potentially protecting against saliva contamination during the first 3 to 4 minutes after mixing GIC. Thermo-light polymerization of the glass carbomer with power outputs of 1000 and 1200 mW/cm 2 also substantially increased FS. The clinical advantages of the findings should be validated by in vivo studies. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Quick Tips for Weight Training Exercise

Science.gov (United States)

Perez, Saul

2004-01-01

Weight training is one of the single most popular types of fitness activities in the United States. One of the reasons for its popularity is that it dramatically contributes to improved strength, muscle tone, body composition, health and appearance. Weight training is a progressive resistance exercise in which resistance is gradually increased as…

Testing and evaluation of a slot and tab construction technique for light-weight wood-fiber-based structural panels under bending

Science.gov (United States)

Jinghao Li; John F. Hunt; Shaoqin Gong; Zhiyong Cai

2015-01-01

This paper presented construction and strain distributions for light-weight wood-fiber-based structural panels with tri-grid core made from phenolic impregnated laminated paper composites under bending. A new fastening configuration of slots in the faces and tabs on the core was applied to the face/core interfaces of the sandwich panel in addition to epoxy resin. Both...

An evaluation of the effects of PEO/PEG molecular weights on extruded alumina rods

Science.gov (United States)

Bolger, Nancy Beth

1998-12-01

Alumina rods were piston extruded from bodies containing polyethylene glycols (PEGs) and polyethylene oxides (PEOs) with molecular weights ranging from 1,300 to 3,800,000 g/mol. A blend of aluminas possessing different particle size distributions was evaluated with regard to its extrusion pressure by varying the amount of PEG/PEO addition. Behavior exhibited by the alumina blend was dependent upon the additive that was used. The higher molecular weight binders with average molecular weight of 200,000 g/mol and 3,350,000 g/mol displayed the most severe behaviors of near dilatant and dilatant respectively. Physical properties of the green and fired states, as well as the binder burnout, were investigated with the changing additions. Correlation between the green and fired strengths and the changing molecular weights were examined. The additive present influenced the surface properties of the rods, which affected the green strengths. The highest average molecular weight polyethylene glycols showed higher green strengths, while the lowest green strengths were observed for the high molecular weight polyethylene oxides. Fired strengths generally ranged from approximately 12,000 psi to 16,000 psi for additive batches. Alumina pellets containing twelve separate combinations of polyethylene glycol with polyethylene oxide were dry pressed. Physical properties of the green and fired states were examined. Statistical analysis was performed upon the data and seven combinations of polyethylene glycol with polyethylene oxide were deemed significant. These combinations in conjunction with the same alumina blend were then piston extruded. The addition of polyethylene glycol reduced the near dilatant behavior exhibited by the 200,000 g/mol average molecular weight polyethylene oxide. Dilatant behavior was completely eliminated from the 3,350,000 g/mol average molecular weight polyethylene oxide batches. Physical properties of the green and fired states were again investigated with

Importance of Performing Experience in Strength Training Periodization

Directory of Open Access Journals (Sweden)

Novosád Adrián

2017-05-01

Full Text Available Proper mastering of a training means seems to be an important determinant of the quality of strength training. Aim of the paper is to examine the differences in strength in relation to squat-performing experience and to offer a way of improving performance by means of increasing the quality of squat technique. Methods 1. Subjects were divided into two groups according to their previous experience with performing squat: a group of inexperienced (n = 9; age: 21.1 years ± 2.37; height: 179.2 cm ± 8.18; weight: 70.0 kg ± 7.38 and experienced (n = 9; age: 24.0 years ± 1.07; height: 182.1 cm ± 4.14; weight: 81.2 kg ± 4.29. We carried out a test of maximal isometric strength in deep squat (ISOmax50° and a modified diagnostic set (Fitro Force Plate which consisted of repetitions of heel raised deep squats with a gradually increasing external loading (FmaxBW+(0-100%. Posture and the body segments of the participants were not corrected during these tests. Mann-Whitney U test (α=0.05 was used to evaluate the data obtained. Results 1. After comparing the differences in the maximal value of force curve in dynamic muscular mode (FmaxBW+(0-100% and the maximal isometric force in deep squat (ISOmax50° between the groups we found significantly bigger differences in the group of experienced when the resistance represented +75 % (Δ 279.0 N and +100 % of body weight (Δ 332.2 N. Methods 2. Eleven inexperienced subjects (age: 22.1 years ± 1.52; weight: 78.2 kg ± 2.84 completed a short term experiment (with 4 training sessions in weeklong microcycle. The purpose was to practise deep squat without any content of targeted strength development.

Simulation of the Vacuum Assisted Resin Transfer Molding (VARTM) process and the development of light-weight composite bridging

Science.gov (United States)

Robinson, Marc J.

A continued desire for increased mobility in the aftermath of natural disasters, or on the battlefield, has lead to the need for improved light-weight bridging solutions. This research investigates the development of a carbon/epoxy composite bridging system to meet the needs for light-weight bridging. The research focuses on two main topics. The first topic is that of processing composite structures and the second is the design and testing of these structures. In recent years the Vacuum Assisted Resin Transfer Molding (VARTM) process has become recognized as a low-cost manufacturing alternative for large Fiber Reinforced Polymer (FRP) composite structures for civil, military, and aerospace applications. The success of the VARTM process (complete wet-out) is very sensitive to the resin injection strategy used and the proper placement of flow distribution materials and inlet and vacuum ports. Predicting the flow front pattern, the time required for infusing a part with resin, and the time required to bleed excess resin at the end of filling, is critical to ensure that the part will become completely impregnated and desired fiber volume fractions achieved prior to the resin gelling (initiation of cure). In order to eliminate costly trial and error experiments to determine the optimal infusion strategy, this research presents a simulation model which considers in-plane flow as well as flow through the thickness of the preform. In addition to resin filling, the current model is able to simulate the bleeding of resin at the end of filling to predict the required bleeding time to reach desired fiber volume fractions for the final part. In addition to processing, the second portion of the dissertation investigates the design and testing of composite bridge deck sections which also serve as short-span bridging for gaps up to 4 m in length. The research focuses on the design of a light-weight core material for bridge decking as well as proof loading of short-span bridge

Atomic structure calculation of energy levels and oscillator strengths in Ti ion, 2

International Nuclear Information System (INIS)

Ishii, Keishi

1983-10-01

Energy levels and oscillator strengths are calculated for 3s-3p and 3p-3d transition arrays in Ti X, isoelectronic to Al I. The energy levels are obtained by the Slater-Condon theory of atomic structure, including explicitly the strong configuration interactions. The results are presented both in numerical tables and in diagrams. In the tables, the observed data are included for comparison, where available. The calculated weighted oscillator strengths (gf-value) are also displayed in figures, where the weighted oscillator strengths are plotted as a function of wavelength. (author)

Supplemental Upward Lighting from Underneath to Obtain Higher Marketable Lettuce (Lactuca sativa) Leaf Fresh Weight by Retarding Senescence of Outer Leaves.

Science.gov (United States)

Zhang, Geng; Shen, Shanqi; Takagaki, Michiko; Kozai, Toyoki; Yamori, Wataru

2015-01-01

Recently, the so-called "plant factory with artificial lighting" (PFAL) approach has been developed to provide safe and steady food production. Although PFALs can produce high-yielding and high-quality plants, the high plant density in these systems accelerates leaf senescence in the bottom (or outer) leaves owing to shading by the upper (or inner) leaves and by neighboring plants. This decreases yield and increases labor costs for trimming. Thus, the establishment of cultivation methods to retard senescence of outer leaves is an important research goal to improve PFAL yield and profitability. In the present study, we developed an LED lighting apparatus that would optimize light conditions for PFAL cultivation of a leafy vegetable. Lettuce (Lactuca sativa L.) was hydroponically grown under white, red, or blue LEDs, with light provided from above (downward), with or without supplemental upward lighting from underneath the plant. White LEDs proved more appropriate for lettuce growth than red or blue LEDs, and the supplemental lighting retarded the senescence of outer leaves and decreased waste (i.e., dead or low-quality senescent leaves), leading to an improvement of the marketable leaf fresh weight.

Effect of Immersion Time in Artificial Saliva on Flexural Strength of Provisional Crown and Bridge Material: Light zPolymerization versus Autopolymerization system

Directory of Open Access Journals (Sweden)

Marzia Magdalena Tetelepta

2013-07-01

Full Text Available Objective: The aim of this study was to investigate the effect of immersion time in artificial salive on the flexural strength of provisional crown and bridge (p-c&b materials. Materials and Methods: Two types of p-c&b materials were used in this study: Light polymerized p-c&b material (Revotek LC and autopolymerized p-c&b material (PerfecTemp II. A total of 100 specimens were fabricated and measured according to ISO 4049/2000. A stainless steel mould was used to prepare 2mmx2mmx25mm bar shaped specimens. All materials were dispensed and manipulated according to the manufacturers' instructions. The specimens were divided into 5 groups (n=10. Each specimen of the first group was measured immediately after preparation. The second, third, fourth and fifth groups were immersed in artificial saliva at 37ºC in an incubator for 1 hour, 1 day, 7 days, and 14 days, respectively. Flexural strength was tested by Universal Mechanical Testing Machine Shimadzu in a 3-point bending test. The repeated ANOVA and Post-Hoc Bonferroni test were used to compare the continuous variables between the groups. Results: The results showed flexural strength of Revotek LC were higher than PerfecTemp II at first and second group. However, flexural strength of PerfecTemp II was higher than Revotek LC at third, fourth, and fifth group. The highest flexural strength of Revotek LC was achieved in 1 hour immersion, whereas PerfecTemp II achieved the highest value in 7 days. Conclusion: Flexural strength of p-c&b materials were influenced by immersion time in artifical saliva and the type of p-c&b materials.DOI: 10.14693/jdi.v17i1.108

Strengthening the composite protective shield of light-weight ship against ballistic impacts: analytical and experimental

Directory of Open Access Journals (Sweden)

I. Jalili

Full Text Available Light and medium protection for small naval vessels guarantees their high performance and safety during the guard duties. In this study, a protective shield fabricated from Dyneema HB25 fibers has been utilized as an add-on layer on the coast guard boat hull. Finite element analyses have been conducted using Chocron's model. Two standards of gun-fire were employed and various thicknesses of the composite layers were examined by ballistic impacts. Afterward, numerical simulations results compared with experiments and revealed a good consistency. Finally, some graphs have been presented to help designers for choosing more convenient shield based on protection and weight characteristics after judgment of vessel requirements.

Sensorimotor memory biases weight perception during object lifting

Directory of Open Access Journals (Sweden)

Vonne evan Polanen

2015-12-01

Full Text Available When lifting an object, the brain uses visual cues and an internal object representation to predict its weight and scale fingertip forces accordingly. Once available, tactile information is rapidly integrated to update the weight prediction and refine the internal object representation. If visual cues cannot be used to predict weight, force planning relies on implicit knowledge acquired from recent lifting experience, termed sensorimotor memory. Here, we investigated whether perception of weight is similarly biased according to previous lifting experience and how this is related to force scaling. Participants grasped and lifted series of light or heavy objects in a semi-randomized order and estimated their weights. As expected, we found that forces were scaled based on previous lifts (sensorimotor memory and these effects increased depending on the length of recent lifting experience. Importantly, perceptual weight estimates were also influenced by the preceding lift, resulting in lower estimations after a heavy lift compared to a light one. In addition, the weight estimations were negatively correlated with the magnitude of planned force parameters. This perceptual bias was only found if the current lift was light, but not heavy since the magnitude of sensorimotor memory effects had, according to Weber’s law, relatively less impact on heavy compared to light objects. A control experiment tested the importance of active lifting in mediating these perceptual changes and showed that when weights are passively applied on the hand, no effect of previous sensory experience is found on perception. These results highlight how fast learning of novel object lifting dynamics can shape weight perception and demonstrate a tight link between action planning and perception control. If predictive force scaling and actual object weight do not match, the online motor corrections, rapidly implemented to downscale forces, will also downscale weight estimation in

Isometric shoulder strength in young swimmers.

Science.gov (United States)

McLaine, Sally J; Ginn, Karen A; Fell, James W; Bird, Marie-Louise

2018-01-01

The prevalence of shoulder pain in young swimmers is high. Shoulder rotation strength and the ratio of internal to external rotation strength have been reported as potential modifiable risk factors associated with shoulder pain. However, relative strength measures in elevated positions, which include flexion and extension, have not been established for the young swimmer. The aim of this study was to establish clinically useful, normative shoulder strength measures and ratios for swimmers (14-20 years) without shoulder pain. Cross-sectional, observational study. Swimmers (N=85) without a recent history of shoulder pain underwent strength testing of shoulder flexion and extension (in 140° abduction); and internal and external rotation (in 90° abduction). Strength tests were performed in supine using a hand-held dynamometer and values normalised to body weight. Descriptive statistics were calculated for strength and strength ratios (flexion:extension and internal:external rotation). Differences between groups (based on gender, history of pain, test and arm dominance) were explored using independent and paired t tests. Normative shoulder strength values and ratios were established for young swimmers. There was a significant difference (pdifferences in strength ratios. Relative strength of the dominant and non-dominant shoulders (except for extension); and for swimmers with and without a history of shoulder pain was not significantly different. A normal shoulder strength profile for the young swimmer has been established which provides a valuable reference for the clinician assessing shoulder strength in this population. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

A Heavy Heart: The Association between Weight and Emotional Words.

Science.gov (United States)

Zhao, Xueru; He, Xianyou; Zhang, Wei

2016-01-01

People often express emotion in language using weight (e.g., a heavy heart, light-hearted, light humor, or heavy-handed), but the question remains whether these expressions of emotion are rooted in the body. Six experiments used a priming paradigm to explore the metaphoric relation between weight perception and emotional words. Experiments 1 and 2 investigated the influence of weight perception on judgments of emotional words and the influence of emotional words on judgments of weight, respectively. A significant difference between the consistent condition (e.g., lightness corresponds to positive words and heaviness corresponds to negative words) and the inconsistent condition (e.g., lightness corresponds to negative words and heaviness corresponds to positive words) was found in Experiment 1 but not in Experiment 2. Experiments 3, 4, and 5 were conducted to exclude potential confounds. Experiment 6 was a repeated-measures study that was conducted to verify the weight-emotion effect. The study confirmed that weight perception affected judgments of emotional words. The results contribute to the growing literature on conceptual metaphor theory and embodied cognition theory.

Compressive strength, flexural strength and thermal conductivity of autoclaved concrete block made using bottom ash as cement replacement materials

International Nuclear Information System (INIS)

Wongkeo, Watcharapong; Thongsanitgarn, Pailyn; Pimraksa, Kedsarin; Chaipanich, Arnon

2012-01-01

Highlights: ► Autoclaved aerated concrete were produced using coal bottom ash as a cement replacement material. ► Coal bottom ash was found to enhance concrete strengths. ► Thermal conductivity of concrete was not significantly affected. ► X-ray diffraction and thermal analysis show tobermorite formation. -- Abstract: The bottom ash (BA) from Mae Moh power plant, Lampang, Thailand was used as Portland cement replacement to produce lightweight concrete (LWC) by autoclave aerated concrete method. Portland cement type 1, river sand, bottom ash, aluminium powder and calcium hydroxide (Ca(OH) 2 ) were used in this study. BA was used to replace Portland cement at 0%, 10%, 20% and 30% by weight and aluminium powder was added at 0.2% by weight in order to produce the aerated concrete. Compressive strength, flexural and thermal conductivity tests were then carried out after the concrete were autoclaved for 6 h and left in air for 7 days. The results show that the compressive strength, flexural strength and thermal conductivity increased with increased BA content due to tobermorite formation. However, approximately, 20% increase in both compressive (up to 11.61 MPa) and flexural strengths (up to 3.16 MPa) was found for mixes with 30% BA content in comparison to just around 6% increase in the thermal conductivity. Thermogravimetry analysis shows C–S–H formation and X-ray diffraction confirm tobermorite formation in bottom ash lightweight concrete. The use of BA as a cement replacement, therefore, can be seen to have the benefit in enhancing strength of the aerated concrete while achieving comparatively low thermal conductivity when compared to the results of the control Portland cement concrete.

Relative contributions of lean and fat mass to bone strength in young Hispanic and non-Hispanic girls.

Science.gov (United States)

Hetherington-Rauth, Megan; Bea, Jennifer W; Blew, Robert M; Funk, Janet L; Hingle, Melanie D; Lee, Vinson R; Roe, Denise J; Wheeler, Mark D; Lohman, Timothy G; Going, Scott B

2018-05-22

With the high prevalence of childhood obesity, especially among Hispanic children, understanding how body weight and its components of lean and fat mass affect bone development is important, given that the amount of bone mineral accrued during childhood can determine osteoporosis risk later in life. The aim of this study was to assess the independent contributions of lean and fat mass on volumetric bone mineral density (vBMD), geometry, and strength in both weight-bearing and non-weight-bearing bones of Hispanic and non-Hispanic girls. Bone vBMD, geometry, and strength were assessed at the 20% distal femur, the 4% and 66% distal tibia, and the 66% distal radius of the non-dominant limb of 326, 9- to 12-year-old girls using peripheral quantitative computed tomography (pQCT). Total body lean and fat mass were measured by dual-energy x-ray absorptiometry (DXA). Multiple linear regression was used to assess the independent relationships of fat and lean mass with pQCT bone measures while adjusting for relevant confounders. Potential interactions between ethnicity and both fat and lean mass were also tested. Lean mass was a significant positive contributor to all bone outcomes (p Lean mass is the main determinant of bone strength for appendicular skeletal sites. Fat mass contributes to bone strength in the weight-bearing skeleton but does not add to bone strength in non-weight-bearing locations and may potentially be detrimental. Bone vBMD, geometry, and strength did not differ between Hispanic and non-Hispanic girls; fat mass may be a stronger contributor to bone strength in weight-bearing bones of Hispanic girls compared to non-Hispanic. Copyright © 2018. Published by Elsevier Inc.

A study on residual stress distribution of welded joints

International Nuclear Information System (INIS)

Huh, Sun Chul; Lee, Kwang Young; Park, Won Jo; Yang, Hae Sug; Junge, Hae Young

2005-01-01

Wings for defense industry such as fighters, missiles, and rockets should have no deformation or damage on the structure, strength, and hardness safety of constituted pared and the structures near to the bodies. The structures of existing wings had holes for light weight and plates and frames were fixed with rivets or screws, thus, there were difficulties and limits in light weight. In this study, an improvement was made in current joint methods through EB welding and laser welding for light weight of wings and welding strength was measured through strength test. In addition, finite element analysis was performed for welding process so as to induce optimum welding condition

Diffusion weighted imaging with circularly polarized oscillating gradients

DEFF Research Database (Denmark)

Lundell, Henrik; Sønderby, Casper Kaae; Dyrby, Tim B

2015-01-01

presented. One major hurdle in practical implementation is the low effective diffusion weighting provided at high frequency with limited gradient strength. THEORY: As a solution to the low diffusion weighting of OGSE, circularly polarized OGSE (CP-OGSE) is introduced. CP-OGSE gives a twofold increase...

The Effect of Weight-Bearing Exercise on the Strength of Femur Bone in Ovariectomized Rats

Directory of Open Access Journals (Sweden)

GH Sharifi

2011-08-01

Full Text Available Introduction & Objective: Fractures due to osteoporosis after menopause in women is widespread. Osteoporosis may occur in case of inadequate lack of physical activity .The aim of this study was to determine the effect of running training on femur bone strength in ovariectomized rats. Materials & Methods Forty matured Sprague Dawley rats were chosen for this study. A group of 10 were killed randomly to measure their initial femur strength. The remaining rats had ovarian surgery. After three months, in order to reach menopause period, they were randomly divided into 3 groups, including pre test, running training and control groups. The running training program was carried out for one hour a day, five days a week, for eight weeks. Femur bone strength was measured by HOUNSFIELD system. Data was analyzed by using one-way analysis of variance and dependent T- tests by the SPSS software. Results: Results of this study showed that ovariectomy leads to significant decrease of femur bone strength. On the other hand the eight weeks running training lead to significant increase of femur bone strength. Conclusion: The results of this study suggest that life style is important factors in preventing of osteoporosis and running training program had an inhibitory or reversal effect on decrease of menopause-induced femur bone strength.

A Weighted Evolving Network with Community Size Preferential Attachment

International Nuclear Information System (INIS)

Zhuo Zhiwei; Shan Erfang

2010-01-01

Community structure is an important characteristic in real complex network. It is a network consists of groups of nodes within which links are dense but among which links are sparse. In this paper, the evolving network include node, link and community growth and we apply the community size preferential attachment and strength preferential attachment to a growing weighted network model and utilize weight assigning mechanism from BBV model. The resulting network reflects the intrinsic community structure with generalized power-law distributions of nodes' degrees and strengths.

Does the light source affect the repairability of composite resins?

Science.gov (United States)

Karaman, Emel; Gönülol, Nihan

2014-01-01

The aim of this study was to examine the effect of the light source on the microshear bond strength of different composite resins repaired with the same substrate. Thirty cylindrical specimens of each composite resin--Filtek Silorane, Filtek Z550 (3M ESPE), Gradia Direct Anterior (GC), and Aelite Posterior (BISCO)--were prepared and light-cured with a QTH light curing unit (LCU). The specimens were aged by thermal cycling and divided into three subgroups according to the light source used--QTH, LED, or PAC (n = 10). They were repaired with the same substrate and a Clearfil Repair Kit (Kuraray). The specimens were light-cured and aged for 1 week in distilled water at 37 °C. The microshear bond strength and failure modes were assessed. There was no significant difference in the microshear bond strength values among the composite resins, except for the Filtek Silorane group that showed significantly lower bond strength values when polymerized with the PAC unit compared to the QTH or LED unit. In conclusion, previously placed dimethacrylate-based composites can be repaired with different light sources; however, if the composite to be repaired is silorane-based, then using a QTH or LED device may be the best option.

Imbedded Nanocrystals of CsPbBr3 in Cs4 PbBr6 : Kinetics, Enhanced Oscillator Strength, and Application in Light-Emitting Diodes.

Science.gov (United States)

Xu, Junwei; Huang, Wenxiao; Li, Peiyun; Onken, Drew R; Dun, Chaochao; Guo, Yang; Ucer, Kamil B; Lu, Chang; Wang, Hongzhi; Geyer, Scott M; Williams, Richard T; Carroll, David L

2017-11-01

Solution-grown films of CsPbBr 3 nanocrystals imbedded in Cs 4 PbBr 6 are incorporated as the recombination layer in light-emitting diode (LED) structures. The kinetics at high carrier density of pure (extended) CsPbBr 3 and the nanoinclusion composite are measured and analyzed, indicating second-order kinetics in extended and mainly first-order kinetics in the confined CsPbBr 3 , respectively. Analysis of absorption strength of this all-perovskite, all-inorganic imbedded nanocrystal composite relative to pure CsPbBr 3 indicates enhanced oscillator strength consistent with earlier published attribution of the sub-nanosecond exciton radiative lifetime in nanoprecipitates of CsPbBr 3 in melt-grown CsBr host crystals and CsPbBr 3 evaporated films. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effects of ultrasonic waves on eggshell strength and hatchability of ...

African Journals Online (AJOL)

tarek shafey

2013-03-13

Mar 13, 2013 ... eggs (Trial 1), and egg weight loss, embryo weight, hatchability and CHW of ... 5, 10 and 15 minutes in a water bath (W5, W10 and W15) or a ULT bath (ULT5, ... eggshell strength between ULT-treated eggs and the control.

Effect of Rebonding on the Bond Strength of Orthodontic Tubes: A Comparison of Light Cure Adhesive and Resin-Modified Glass Ionomer Cement In Vitro

Directory of Open Access Journals (Sweden)

Monika Aleksiejunaite

2017-01-01

Full Text Available The purpose of this study was to determine the impact of different enamel preparation procedures and compare light cure composite (LCC and resin-modified glass ionomer (RMGI on the bond strength of orthodontic metal tubes rebonded to the enamel. Twenty human molars were divided into two groups (n=10. Tubes were bonded using LCC (Transbond XT in group 1 and RMGI (Fuji Ortho LC in group 2. The tubes in each group were bonded following manufacturers’ instructions (experiment I and then debonded using testing machine. Then, the same brackets were sandblasted and rebonded twice. Before the first rebonding, the enamel was cleaned using carbide bur (experiment II and before second rebonding, it was cleaned using carbide bur and soda blasted (experiment III. Mann–Whitney and Wilcoxon signed-rank tests showed no significant difference between RMGI and LCC bond strengths in case of normal bonding and rebonding, when enamel was cleaned using carbide bur before rebonding. Enamel soda blasting before rebonding significantly increased RMGI tensile bond strength value compared to LLC (p<0.05. LCC and RMGI (especially RMGI provide sufficient bond strengths for rebonding of molar tubes, when residual adhesive from previous bonding is removed and enamel soda blasted.

Effects of four dim vs high intensity red color light regimens on growth performance and welfare of broilers

Directory of Open Access Journals (Sweden)

D. Senaratna

2018-01-01

Full Text Available Objective Broilers show clear preference towards red color light (RL. However setting of an optimum light intensity is difficult since dim intensities that favor growth reduce welfare. This experiment was conducted to test the most effective RL intensity regimen (Dim [5 lux; DI] vs high [320 lux; HI] in combination applied at different growth stages that favors for both performance and welfare. Methods Complete randomize design was adopted with 6 replicates. Treatments were; T1 = early DI (8–21 d+latter HI (22–35 d; T2 = early DI (8–28 d+latter HI (29–35 d, T3 = early HI (8–21 d+latter DI (22–35 d, T4 = early HI (8–28 d+latter DI (29–35 d and T5 = control (white light; WT (8–35 d at medium intensity (20 lux. Body weight (BW, weight gain (WG, water/feed intake and ratio, feed conversion ratios (FCR were assessed. Common behaviours (15 were recorded by scan sampling method. Lameness, foot pad dermatitis, breast blisters, hock burning damage were assessed as welfare parameters. Fear reactions were tested using Tonic Immobility Test. Ocular and carcass evaluations were done. Meat and tibiae were analyzed for fat and bone ash respectively. Results On 35 d, the highest BW (2,155.72±176 g, WG (1,967.78±174 g were recorded by T2 compared to WT (BWWT = 1,878.22±155, WGWT = 1,691.83±160. But, application of RL, either DI, or HI during early/latter stage had no significant effect on FCR. Under HI, birds showed much higher active behaviours. DI encourages eating. Though LI changed from DI to HI, same trend could be seen even under HI. The highest leg strength (218.5±120 s was recorded by T2. The lowest leg strength (64.58±33 s and the highest ocular weight (2.48±1 g were recorded by T1. Significantly (p<0.05 the highest skin weight (162.17±6 g but the lowest fat% in meat (13.03%±5% was recorded by T2. Conclusion Early exposure to DI-RL up to 28 days followed by exposure to HI-RL is the most favorable lighting regimen for

CONTROL DE MALEZA EN DISTRITOS DE RIEGO CON EQUIPOS LIGEROS WEED CONTROL IN IRRIGATION DISTRICTS WITH LIGHT WEIGHT EQUIPMENT

Directory of Open Access Journals (Sweden)

José Ramón Lomelí Villanueva

2010-12-01

Full Text Available En México el control mecánico de maleza, tradicionalmente se realizaba con maquinaria inadecuada lo cual provocaba daños en los taludes y modificaciones de la sección hidráulica. Para resolver este problema, actualmente se utilizan los equipos ligeros que permiten el desarrollo de una cubierta vegetal, que no interfiere con el flujo del agua y su sistema radical retiene el suelo, lo cual reduce la erosión y mantiene en condiciones estables los taludes. El presente trabajo aborda los aspectos relativos a características y criterios para la selección de los implementos y la secuencia para su utilización. El costo de las operaciones para el control de maleza en canales, drenes y caminos se ha reducido un 39,21% con respecto a utilizar maquinaria inadecuada. La versatilidad de los equipos ligeros permite emplear el implemento más adecuado para cada tipo de maleza. En México, el inventario actual es de 263 equipos ligeros que tienen un potencial de aplicación para el control de la maleza, en la totalidad de los caminos, el 90% de canales y el 70% de drenes de los Distritos de Riego.In Mexico, the mechanical weed control was traditionally carried out with inadequate equipment which caused damage to the slopes and changes in the hydraulic section. In order to solve this problem, light weight equipment is currently being used to allow the development of a vegetation cover to retain soil with no interference with water flow, reducing erosion and maintaining stable conditions in the slopes. This paper addresses aspects related to characteristics and criteria for selecting and sequencing tools for use. The costs of weed control in irrigation channels, drains and roads have been reduced 39.21% compared to using inadequate equipment. The versatility of light weight equipment allows the use of the most appropriate implement for each weed. In Mexico, the current inventory includes 263 light weight devices with which a potential weed control of 90

A Heavy Heart: The Association between Weight and Emotional Words

OpenAIRE

Zhao, Xueru; He, Xianyou; Zhang, Wei

2016-01-01

People often express emotion in language using weight (e.g., a heavy heart, light-hearted, light humor, or heavy-handed), but the question remains whether these expressions of emotion are rooted in the body. Six experiments used a priming paradigm to explore the metaphoric relation between weight perception and emotional words. Experiments 1 and 2 investigated the influence of weight perception on judgments of emotional words and the influence of emotional words on judgments of weight, respec...

Age, weight, and the front abdominal power test as predictors of isokinetic trunk strength and work in young men and women.

Science.gov (United States)

Cowley, Patrick M; Fitzgerald, Sharon; Sottung, Kyle; Swensen, Thomas

2009-05-01

First we tested the reliability of two new field tests of core stability (plank to fatigue test [PFT] and front abdominal power test [FAPT]), as well as established measures of core stability (isokinetic trunk extension and flexion strength [TES and TFS] and work [TEW and TFW]) over 3 days in 8 young men and women (24.0 +/- 3.1 years). The TES, TFS, TFW, and FAPT were highly reliable, TEW was moderately reliable, and PFT were unreliable for use during a single testing session. Next, we determined if age, weight, and the data from the reliable field test (FAPT) were predictive of TES, TEW, TFS, and TFW in 50 young men and women (19.0 +/- 1.2 years). The FAPT was the only significant predictor of TES and TEW in young women, explaining 16 and 15% of the variance in trunk performance, respectively. Weight was the only significant predictor of TFS and TFW in young women, explaining 28 and 14% of the variance in trunk performance, respectively. In young men, weight was the only significant predictor of TES, TEW, TFS, and TFW, and explained 27, 35, 42, and 33%, respectively, of the variance in trunk performance. In conclusion, the ability of weight and the FAPT to predict TES, TEW, TFS, and TFW was more frequent in young men than women. Additionally, because the FAPT requires few pieces of equipment, is fast to administer, and predicts isokinetic TES and TEW in young women, it can be used to provide a field-based estimate of isokinetic TES and TEW in women without history of back or lower-extremity injury.

High Chamber Pressure, Light Weight Thrusters, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The performance liquid propellant engines can be significantly improved by increasing both combustion temperature and pressure and reducing engine weight. State of...

A tele-operated mobile ultrasound scanner using a light-weight robot.

Science.gov (United States)

Delgorge, Cécile; Courrèges, Fabien; Al Bassit, Lama; Novales, Cyril; Rosenberger, Christophe; Smith-Guerin, Natalie; Brù, Concepció; Gilabert, Rosa; Vannoni, Maurizio; Poisson, Gérard; Vieyres, Pierre

2005-03-01

This paper presents a new tele-operated robotic chain for real-time ultrasound image acquisition and medical diagnosis. This system has been developed in the frame of the Mobile Tele-Echography Using an Ultralight Robot European Project. A light-weight six degrees-of-freedom serial robot, with a remote center of motion, has been specially designed for this application. It holds and moves a real probe on a distant patient according to the expert gesture and permits an image acquisition using a standard ultrasound device. The combination of mechanical structure choice for the robot and dedicated control law, particularly nearby the singular configuration allows a good path following and a robotized gesture accuracy. The choice of compression techniques for image transmission enables a compromise between flow and quality. These combined approaches, for robotics and image processing, enable the medical specialist to better control the remote ultrasound probe holder system and to receive stable and good quality ultrasound images to make a diagnosis via any type of communication link from terrestrial to satellite. Clinical tests have been performed since April 2003. They used both satellite or Integrated Services Digital Network lines with a theoretical bandwidth of 384 Kb/s. They showed the tele-echography system helped to identify 66% of lesions and 83% of symptomatic pathologies.

High-strength cellular ceramic composites with 3D microarchitecture.

Science.gov (United States)

Bauer, Jens; Hengsbach, Stefan; Tesari, Iwiza; Schwaiger, Ruth; Kraft, Oliver

2014-02-18

To enhance the strength-to-weight ratio of a material, one may try to either improve the strength or lower the density, or both. The lightest solid materials have a density in the range of 1,000 kg/m(3); only cellular materials, such as technical foams, can reach considerably lower values. However, compared with corresponding bulk materials, their specific strength generally is significantly lower. Cellular topologies may be divided into bending- and stretching-dominated ones. Technical foams are structured randomly and behave in a bending-dominated way, which is less weight efficient, with respect to strength, than stretching-dominated behavior, such as in regular braced frameworks. Cancellous bone and other natural cellular solids have an optimized architecture. Their basic material is structured hierarchically and consists of nanometer-size elements, providing a benefit from size effects in the material strength. Designing cellular materials with a specific microarchitecture would allow one to exploit the structural advantages of stretching-dominated constructions as well as size-dependent strengthening effects. In this paper, we demonstrate that such materials may be fabricated. Applying 3D laser lithography, we produced and characterized micro-truss and -shell structures made from alumina-polymer composite. Size-dependent strengthening of alumina shells has been observed, particularly when applied with a characteristic thickness below 100 nm. The presented artificial cellular materials reach compressive strengths up to 280 MPa with densities well below 1,000 kg/m(3).

Effect of pulsed current welding on fatigue behaviour of high strength aluminium alloy joints

International Nuclear Information System (INIS)

Balasubramanian, V.; Ravisankar, V.; Madhusudhan Reddy, G.

2008-01-01

High strength aluminium alloys (Al-Zn-Mg-Cu alloys) have gathered wide acceptance in the fabrication of light weight structures requiring high strength-to weight ratio, such as transportable bridge girders, military vehicles, road tankers and railway transport systems. The preferred welding processes of high strength aluminium alloy are frequently gas tungsten arc welding (GTAW) process and gas metal arc welding (GMAW) process due to their comparatively easier applicability and better economy. Weld fusion zones typically exhibit coarse columnar grains because of the prevailing thermal conditions during weld metal solidification. This often results inferior weld mechanical properties and poor resistance to hot cracking. In this investigation, an attempt has been made to refine the fusion zone grains by applying pulsed current welding technique. Rolled plates of 6 mm thickness have been used as the base material for preparing single pass welded joints. Single V butt joint configuration has been prepared for joining the plates. The filler metal used for joining the plates is AA 5356 (Al-5Mg (wt%)) grade aluminium alloy. Four different welding techniques have been used to fabricate the joints and they are: (i) continuous current GTAW (CCGTAW), (ii) pulsed current GTAW (PCGTAW), (iii) continuous current GMAW (CCGMAW) and (iv) pulsed current GMAW (PCGMAW) processes. Argon (99.99% pure) has been used as the shielding gas. Fatigue properties of the welded joints have been evaluated by conducting fatigue test using rotary bending fatigue testing machine. Current pulsing leads to relatively finer and more equi-axed grain structure in gas tungsten arc (GTA) and gas metal arc (GMA) welds. In contrast, conventional continuous current welding resulted in predominantly columnar grain structures. Grain refinement is accompanied by an increase in fatigue life and endurance limit

Effects of four dim vs high intensity red color light regimens on growth performance and welfare of broilers.

Science.gov (United States)

Senaratna, D; Samarakone, T S; Gunawardena, W W D A

2018-01-01

Broilers show clear preference towards red color light (RL). However setting of an optimum light intensity is difficult since dim intensities that favor growth reduce welfare. This experiment was conducted to test the most effective RL intensity regimen (Dim [5 lux; DI] vs high [320 lux; HI]) in combination applied at different growth stages that favors for both performance and welfare. Complete randomize design was adopted with 6 replicates. Treatments were; T1 = early DI (8-21 d)+latter HI (22-35 d); T2 = early DI (8-28 d)+latter HI (29-35 d), T3 = early HI (8-21 d)+latter DI (22-35 d), T4 = early HI (8-28 d)+latter DI (29-35 d) and T5 = control (white light; WT) (8-35 d) at medium intensity (20 lux). Body weight (BW), weight gain (WG), water/feed intake and ratio, feed conversion ratios (FCR) were assessed. Common behaviours (15) were recorded by scan sampling method. Lameness, foot pad dermatitis, breast blisters, hock burning damage were assessed as welfare parameters. Fear reactions were tested using Tonic Immobility Test. Ocular and carcass evaluations were done. Meat and tibiae were analyzed for fat and bone ash respectively. On 35 d, the highest BW (2,155.72±176 g), WG (1,967.78±174 g) were recorded by T2 compared to WT (BW WT = 1,878.22±155, WG WT = 1,691.83±160). But, application of RL, either DI, or HI during early/latter stage had no significant effect on FCR. Under HI, birds showed much higher active behaviours. DI encourages eating. Though LI changed from DI to HI, same trend could be seen even under HI. The highest leg strength (218.5±120 s) was recorded by T2. The lowest leg strength (64.58±33 s) and the highest ocular weight (2.48±1 g) were recorded by T1. Significantly (plighting regimen for optimizing production, better welfare of broilers and improving health benefits of meat.

Sizing Optimization and Strength Analysis for Spread-type Gear Reducers

Directory of Open Access Journals (Sweden)

Wei-Hsuan Hsu

2014-08-01

Full Text Available A reducer is now developed towards the trend of customization service and cost-saving. In this study, a sizing program for the reducer has been developed in order to replace the manual sizing process. We aim at the total center distance of the gear reducer for optimization to reduce gear volume and weight. Also, we checked constrains such as, tooth root bending, tooth contact strength, gear shaft endangered cross-section, bearing life, gear shaft deflection, and torsion angle deformation, etc., to obtain reliable drive strength. Comparisons of sizes and weights before and after optimization confirm that the purpose for reducing production cost is achieved.

Preliminary investigations of potential light weight metallic armour applications

NARCIS (Netherlands)

Voorde, M.J. van de; Diederen, A.M.; Herlaar, K.

2005-01-01

Now that an industrial-scale low-cost production route for ballistic-grade titanium is within reach, the potential use of titanium armour could depend on a solution for the spalling of high strength titanium. This paper addresses a titanium based metal laminate as being a possible solution for the

Weighted f-values, A-values, and line strengths for the E1 transitions among 3d6, 3d54s, and 3d54p levels of Fe III

International Nuclear Information System (INIS)

Deb, Narayan C.; Hibbert, Alan

2009-01-01

Weighted oscillator strengths, weighted radiative rates, and line strengths for all the E1 transitions between 285 fine-structure levels belonging to the 3d 6 , 3d 5 4s, and 3d 5 4p configurations of Fe III are presented, in ascending order of wavelength. Calculations have been undertaken using the general configuration interaction (CI) code CIV3. The large configuration set is constructed by allowing single and double replacements from any of 3d 6 , 3d 5 4s, 3d 5 4p, and 3d 5 4d configurations to nl orbitals with n≤5,l≤3 as well as 6p. Additional selective promotions from 3s and 3p subshells are also included in the CI expansions to incorporate the important correlation effects in the n=3 shell. Results of some strong transitions between levels of 3d 6 , 3d 5 4s, and 3d 5 4p configurations are also presented and compared with other available calculations. It is found that large disagreements occur in many transitions among the existing calculations

Hindlimb Skeletal Muscle Function and Skeletal Quality and Strength in +/G610C Mice With and Without Weight-Bearing Exercise.

Science.gov (United States)

Jeong, Youngjae; Carleton, Stephanie M; Gentry, Bettina A; Yao, Xiaomei; Ferreira, J Andries; Salamango, Daniel J; Weis, MaryAnn; Oestreich, Arin K; Williams, Ashlee M; McCray, Marcus G; Eyre, David R; Brown, Marybeth; Wang, Yong; Phillips, Charlotte L

2015-10-01

Osteogenesis imperfecta (OI) is a heterogeneous heritable connective tissue disorder associated with reduced bone mineral density and skeletal fragility. Bone is inherently mechanosensitive, with bone strength being proportional to muscle mass and strength. Physically active healthy children accrue more bone than inactive children. Children with type I OI exhibit decreased exercise capacity and muscle strength compared with healthy peers. It is unknown whether this muscle weakness reflects decreased physical activity or a muscle pathology. In this study, we used heterozygous G610C OI model mice (+/G610C), which model both the genotype and phenotype of a large Amish OI kindred, to evaluate hindlimb muscle function and physical activity levels before evaluating the ability of +/G610C mice to undergo a treadmill exercise regimen. We found +/G610C mice hindlimb muscles do not exhibit compromised muscle function, and their activity levels were not reduced relative to wild-type mice. The +/G610C mice were also able to complete an 8-week treadmill regimen. Biomechanical integrity of control and exercised wild-type and +/G610C femora were analyzed by torsional loading to failure. The greatest skeletal gains in response to exercise were observed in stiffness and the shear modulus of elasticity with alterations in collagen content. Analysis of tibial cortical bone by Raman spectroscopy demonstrated similar crystallinity and mineral/matrix ratios regardless of sex, exercise, and genotype. Together, these findings demonstrate +/G610C OI mice have equivalent muscle function, activity levels, and ability to complete a weight-bearing exercise regimen as wild-type mice. The +/G610C mice exhibited increased femoral stiffness and decreased hydroxyproline with exercise, whereas other biomechanical parameters remain unaffected, suggesting a more rigorous exercise regimen or another exercise modality may be required to improve bone quality of OI mice. © 2015 American Society for Bone

Environmental safety analysis tests on the Light Weight Radioisotope Heater Unit (LWRHU)

International Nuclear Information System (INIS)

Tate, R.E.; Land, C.C.

1985-05-01

A series of safety tests has been performed on the Light Weight Radioisotope Heater Unit (LWRHU), a 238 PuO 2 -fueled device designed to provide thermal energy at selected locations in a spacecraft. The tests simulate the thermal and mechanical environments postulated for spacecraft accidents on the launch pad and on reentry abort. The tests demonstrate almost complete containment of the fuel, or fuel simulant (depleted UO 2 ), in (1) an overpressure environment of 12.76 MPa (1850 psi), (2) on impact by an 18-g aluminum fuel-tank fragment at velocities greater than 750 m/s (2460 ft/s) but less than 900 m/s (2950 ft/s), (3) during a 10.5-min burn of a 0.9 x 0.9 x 0.9 m (3 x 3 x 3 ft) block of solid rocket motor propellant, (4) after impact at 49 m/s (161 ft/s) in four different orientations on a hard surface, and (5) during immersion in seawater for 1.75 years at both sea level pressure and at a pressure equivalent to 6000 m (19,700 ft) of ocean depth

Green strength of zirconium sponge and uranium dioxide powder compacts

International Nuclear Information System (INIS)

Balakrishna, Palanki; Murty, B. Narasimha; Sahoo, P.K.; Gopalakrishna, T.

2008-01-01

Zirconium metal sponge is compacted into rectangular or cylindrical shapes using hydraulic presses. These shapes are stacked and electron beam welded to form a long electrode suitable for vacuum arc melting and casting into solid ingots. The compact electrodes should be sufficiently strong to prevent breakage in handling as well as during vacuum arc melting. Usually, the welds are strong and the electrode strength is limited by the green strength of the compacts, which constitute the electrode. Green strength is also required in uranium dioxide (UO 2 ) powder compacts, to withstand stresses during de-tensioning after compaction as well as during ejection from the die and for subsequent handling by man and machine. The strengths of zirconium sponge and UO 2 powder compacts have been determined by bending and crushing respectively, and Weibul moduli evaluated. The green density of coarse sponge compact was found to be larger than that from finer sponge. The green density of compacts from lightly attrited UO 2 powder was higher than that from unattrited category, accompanied by an improvement in UO 2 green crushing strength. The factors governing green strength have been examined in the light of published literature and experimental evidence. The methodology and results provide a basis for quality control in metal sponge and ceramic powder compaction in the manufacture of nuclear fuel

Short-term Periodization Models: Effects on Strength and Speed-strength Performance.

Science.gov (United States)

Hartmann, Hagen; Wirth, Klaus; Keiner, Michael; Mickel, Christoph; Sander, Andre; Szilvas, Elena

2015-10-01

avoided because it does not provide an adequate training stimulus for gains in muscle cross-sectional area and strength performance. High-volume circuit strength training performed over 2 years negatively affected the development of the power output and maximal strength of the upper extremities in professional rugby players. Indeed, meta-analyses and results with weightlifters, American Football players, and throwers confirm the necessity of the habitual use of ≥80% 1 RM: (1) to improve maximal strength during the off-season and in-season in American Football, (2) to reach peak performance in maximal strength and vertical jump power during tapering in track-and-field, and (3) to produce hypertrophy and strength improvements in advanced athletes. The integration and extent of hypertrophy strength training in in-season conditioning depend on the duration of the contest period, the frequency of the contests, and the proportion of the conditioning program. Based on the literature, 72 h between hypertrophy strength training and strength-power training should be provided to allow for adequate regeneration times and therefore maximal stimulus intensities in training. This conclusion is only valid if the muscle is not trained otherwise during this regeneration phase. Thus, rotating hypertrophy and strength-power sessions in a microcycle during the season is a viable option. Comparative studies in competitive athletes who integrated strength training during pre-season conditioning confirm a tendency for gains in explosive strength and statistically significant improvements in medicine ball throw through SPP but not through daily undulating periodization. These findings indicate that to maximize the speed-strength in the short term (peaking), elite athletes should perform strength-power training twice per week. It is possible to perform a single strength-power session with the method of maximum explosive strength actions moving high-weight loads (90% 1 repetition maximum [RM]) at

Neurologic disorders associated with weight lifting and bodybuilding.

Science.gov (United States)

Busche, Kevin

2009-02-01

Weight lifting and other forms of strength training are becoming more common because of an increased awareness of the need to maintain individual physical fitness. Emergency room data indicate that injuries caused by weight training have become more universal over time, likely because of increased participation rates. Neurologic injuries can result from weight lifting and related practices. Although predominantly peripheral nervous system injuries have been described, central nervous system disease may also occur. This article illustrates the types of neurologic disorders associated with weight lifting.

Miniature radioactive light source

International Nuclear Information System (INIS)

Caffarella, T.E.; Radda, G.J.; Dooley, H.H.

1980-01-01

A miniature radioactive light source for illuminating digital watches is described consisting of a glass tube with improved laser sealing and strength containing tritium gas and a transducer responsive to the gas. (U.K.)

An Annotated Bibliography of Isotonic Weight-Training Methods.

Science.gov (United States)

Wysong, John V.

This literature study was conducted to compare and evaluate various types and techniques of weight lifting so that a weight lifting program could be selected or devised for a secondary school. Annotations of 32 research reports, journal articles, and monographs on isotonic strength training are presented. The literature in the first part of the…

G phase precipitation and strengthening in ultra-high strength ferritic steels: Towards lean ‘maraging’ metallurgy

International Nuclear Information System (INIS)

Sun, W.W.; Marceau, R.K.W.; Styles, M.J.; Barbier, D.; Hutchinson, C.R.

2017-01-01

Ultra-high strength steels are interesting materials for light-weighting applications in the transportation industries. A key requirement of these applications is weldability and consequently a low carbon content is desirable. Maraging steels are examples of ultra-high strength, low carbon steels but their disadvantage is their high cost due to the large Ni and/or Co additions required. This contribution is focussed on the development of steels with maraging-like strengths but with low solute contents (less than 10%). A series of alloy compositions were designed to exploit precipitation of the G phase in a ferritic matrix at temperatures of 450–600 °C in order to obtain yield strengths in excess of 2 GPa. The mechanical response of the materials was measured using tension and compression testing and the precipitate evolution has been characterized using atom probe tomography (APT) and in-situ small angle X-ray scattering (SAXS) at a synchrotron beamline. Precipitate number densities of 10"2"5 m"−"3 are obtained, which are amongst the highest number densities so far observed in engineering alloys. The intrinsic strength of the G phase is shown to be proportional to its size, and deviations in the chemistry of the precipitates do not significantly affect their strengthening behaviour. An important outcome is that the common temper embrittlement issues known to occur during aging of martensite in the 450–600 °C range were mitigated in one alloy by starting with a cold-rolled and partially fragmented lath martensite instead of a freshly quenched martensite.

Effect of ecological surface treatment method on friction strength properties of nettle (urtica dioica) fibre yarns

Science.gov (United States)

Şansal, S.; Mıstık, S. I.; Fettahov, R.; Ovalı, S.; Duman, M.

2017-10-01

Over the last few decades, more attention is given to lignocellulose based fibres as reinforcement material in the polymer composites owing to the environmental pollution caused by the extensive usage of synthetic and inorganic fibres. Developing new natural fibre reinforced composites is the focus of many researches nowadays. They are made from renewable resources and they have less environmental effect in comparison to inorganic fibre reinforced composites. The interest of consumers in eco-friendly natural fibres and textiles has increased in recent years. Unlike inorganic fibres, natural fibres present light weight, high strength/density ratio and are readily available, environmentally friendly and biodegradable. Many different types of natural fibres are exploited for the production of biodegradable polymer composites. The nettle (Urtica dioica L.) is a well-known plant growing on rural sites of Europe, Asia, and North America. Nettle plant contains fibre similar to hemp and flax. However, similar to other natural fibres, nettle fibres are poorly compatible with the thermoplastic matrix of composites, due to their hydrophilic character which reduces mechanical properties of nettle fibre reinforced thermoplastics. In order to improve the fibrematrix adhesion of the natural fibre reinforced composites, surface treatment processes are applied to the lignocellulose fibres. In this study nettle (urtica dioica) fibre yarns were treated with NaOH by using conventional, ultrasonic and microwave energy methods. After treatment processes tensile strength, elongation, friction strength and SEM observations of the nettle fibre yarns were investigated. All treatment processes were improved the tensile strength, elongation and friction strength properties of the nettle fibre yarns. Also higher tensile strength, elongation and friction strength properties were obtained from treated nettle fibre yarns which treated by using microwave energy method.

Strength Training. A Key to Athletic Training.

Science.gov (United States)

Whiteside, Patricia W.

Characteristics of an effective strength training program are analyzed and descriptions are offered of different kinds of weight training activities. Comparisons are made between concentric, isometric, eccentric, and isokinetic training methods. The fundamentals and techniques of an exemplary training program are outlined and the organization and…

Structure and growth of weighted networks

Energy Technology Data Exchange (ETDEWEB)

Riccaboni, Massimo [Department of Computer and Management Sciences, University of Trento, Trento (Italy); Schiavo, Stefano [Department of Economics, University of Trento, Trento (Italy)], E-mail: massimo.riccaboni@unitn.it, E-mail: stefano.schiavo@unitn.it

2010-02-15

We develop a simple theoretical framework for the evolution of weighted networks that is consistent with a number of stylized features of real-world data. In our framework, the Barabasi-Albert model of network evolution is extended by assuming that link weights evolve according to a geometric Brownian motion. Our model is verified by means of simulations and real-world trade data. We show that the model correctly predicts the intensity and growth distribution of links, the size-variance relationship of the growth of link weights, the relationship between the degree and strength of nodes, and the scale-free structure of the network.

Single-Leg Hop Test Performance and Isokinetic Knee Strength After Anterior Cruciate Ligament Reconstruction in Athletes.

Science.gov (United States)

Sueyoshi, Ted; Nakahata, Akihiro; Emoto, Gen; Yuasa, Tomoki

2017-11-01

Isokinetic strength and hop tests are commonly used to assess athletes' readiness to return to sport after knee surgery. The purpose of this study was to investigate the results of single-leg hop and isokinetic knee strength testing in athletes who underwent anterior cruciate ligament reconstruction (ACLR) upon returning to sport participation as well as to study the correlation between these 2 test batteries. The secondary purpose was to compare the test results by graft type (patellar tendon or hamstring). It was hypothesized that there would be no statistically significant limb difference in either isokinetic knee strength or single-leg hop tests, that there would be a moderate to strong correlation between the 2 test batteries, and that there would be no significant difference between graft types. Cross-sectional study; Level of evidence, 3. Twenty-nine high school and collegiate athletes who underwent ACLR participated in this study. At the time of return to full sport participation, a series of hop tests and knee extension/flexion isokinetic strength measurements were conducted. The results were analyzed using analysis of variance and Pearson correlation ( r ). The timed 6-m hop test was the only hop test that showed a significant difference between the involved and uninvolved limbs (2.3 and 2.2 seconds, respectively; P = .02). A significant difference between limbs in knee strength was found for flexion peak torque/body weight at 180 deg/s ( P = .03), flexion total work/body weight at 180 deg/s ( P = .04), and flexion peak torque/body weight at 300 deg/s ( P = .03). The strongest correlation between the hop tests and knee strength was found between the total distance of the hop tests and flexion total work/body weight at 300 deg/s ( r = 0.69) and between the timed 6-m hop test and flexion peak torque/body weight at 300 deg/s ( r = -0.54). There was no statistically significant difference in hop test performance or isokinetic knee strength between graft types

Effect of Parental Live Weight on the Reproductive Performance of ...

African Journals Online (AJOL)

High mortality was obtained from HM x HF and HM x LF crosses. This study concluded that light male and light female crosses gave chicks with better post hatching performance and lowest mortality rate than all other crosses. Keywords: Parental live weight, Egg weight, Hatchability, Fertility, Crosses, Japanese quail ...

Observation of monopole strength in the 12C(e,e'p0)11B reaction

International Nuclear Information System (INIS)

Calarco, J.R.; Arruda-Neto, J.; Griffioen, K.A.; Hanna, S.S.; Hoffmann, D.H.H.; Neyer, B.; Rand, R.E.; Wienhard, K.; Yearian, M.R.

1984-01-01

The location of the giant monopole resonance and, therefore, the compressibility is unknown in light nuclei. The forward-backward (e, e'p) angular correlation asymmetry from 12 C has been measured and found to be very sensitive to monopole strength in the giant dipole resonance region. Similar reactions will, thus, provide a sensitive tool in the search for monopole strength in light nuclei. (orig.)

Isokinetic and isometric strength-endurance after 6 hours of immersion and 6 degrees head-down tilt in men

Science.gov (United States)

Shaffer-Bailey, M.; Greenleaf, J. E.; Hutchinson, T. M.

1996-01-01

PURPOSE: To determine weight (water) loss levels for onset of muscular strength and endurance changes during deconditioning. METHODS: Seven men (27-40 yr) performed maximal shoulder-, knee-, and ankle-joint isometric (0 degree.s(-1) load) and isokinetic (60 degrees, 120 degrees, 180 degrees.s(-1) velocity) exercise tests during ambulatory control (AC), after 6 h of 6 degrees head-down tilt (HDT; dry-bulb temp. = 23.2 +/- SD 0.6 degrees C, relative humidity = 31.1+/- 11.1%) and after 6 h of 80 degrees foot-down head-out water immersion (WI; water temp. = 35.0 +/- SD 0.1 degree C) treatments. RESULTS: Weight (water) loss after HDT (1.10 +/- SE 0.14 kg, 1.4 +/- 0.2% body wt) and WI (1.54+/- 0.19 kg, 2.0 +/- 0.2% body wt) were not different, but urinary excretion with WI (1,354 +/- 142 ml.6 h(-1)) was 28% greater (p strength was unchanged except for three knee-joint peak torques: AC torque (120 degrees.s(-1), 285 +/- 20 Nm) decreased to 268 +/- 21 Nm (delta = -6%, p strength and endurance decrements is more than 2% body weight (water) loss, while significant reduction in knee-joint muscular strength-endurance occurred only at moderate (120 degrees.s(-1) and lighter (180 degrees.s(-1)) loads with body weight loss of 1.4-2.0% following WI or HDT, respectively. These weight (water) losses and knee-joint strength decrements are somewhat less than the mean weight loss of 2.6% and knee-joint strength decrements of 6-20% of American astronauts after Skylab flights to 84 d.

The low molecular weight protein PsaI stabilizes the light-harvesting complex II docking site of photosystem I

DEFF Research Database (Denmark)

Plöchinger, Magdalena; Torabi, Salar; Rantala, Marjaana

2016-01-01

PsaI represents one of three low molecular weight peptides of PSI. Targeted inactivation of the plastid PsaI gene in Nicotiana tabacum has no measurable effect on photosynthetic electron transport around PSI or on accumulation of proteins involved in photosynthesis. Instead, the lack of Psa......I destabilizes the association of PsaL and PsaH to PSI, both forming the light-harvesting complex (LHC)II docking site of PSI. These alterations at the LHCII binding site surprisingly did not prevent state transition but led to an increased incidence of PSI-LHCII complexes, coinciding with an elevated...

Design of segmented thermoelectric generator based on cost-effective and light-weight thermoelectric alloys

International Nuclear Information System (INIS)

Kim, Hee Seok; Kikuchi, Keiko; Itoh, Takashi; Iida, Tsutomu; Taya, Minoru

2014-01-01

Highlights: • Segmented thermoelectric (TE) module operating at 500 °C for combustion engine system. • Si based light-weight TE generator increases the specific power density [W/kg]. • Study of contact resistance at the bonding interfaces maximizing output power. • Accurate agreement of the theoretical predictions with experimental results. - Abstract: A segmented thermoelectric (TE) generator was designed with higher temperature segments composed of n-type Mg 2 Si and p-type higher manganese silicide (HMS) and lower temperature segments composed of n- and p-type Bi–Te based compounds. Since magnesium and silicon based TE alloys have low densities, they produce a TE module with a high specific power density that is suitable for airborne applications. A two-pair segmented π-shaped TE generator was assembled with low contact resistance materials across bonding interfaces. The peak specific power density of this generator was measured at 42.9 W/kg under a 498 °C temperature difference, which has a good agreement with analytical predictions

[Compressive and bend strength of experimental admixed high copper alloys].

Science.gov (United States)

Sourai, P; Paximada, H; Lagouvardos, P; Douvitsas, G

1988-01-01

Mixed alloys for dental amalgams have been used mainly in the form of admixed alloys, where eutectic spheres are blend with conventional flakes. In the present study the compressive strength, bend strength and microstructure of two high-copper alloys (Tytin, Ana-2000) is compared with three experimental alloys prepared of the two high copper by mixing them in proportions of 3:1, 1:1 and 1:3 by weight. The results revealed that experimental alloys inherited high early and final strength values without any significant change in their microstructure.

Beam Steering Devices Reduce Payload Weight

Science.gov (United States)

2012-01-01

Scientists have long been able to shift the direction of a laser beam, steering it toward a target, but often the strength and focus of the light is altered. For precision applications, where the quality of the beam cannot be compromised, scientists have typically turned to mechanical steering methods, redirecting the source of the beam by swinging the entire laser apparatus toward the target. Just as the mechanical methods used for turning cars has evolved into simpler, lighter, power steering methods, so has the means by which researchers can direct lasers. Some of the typical contraptions used to redirect lasers are large and bulky, relying on steering gimbals pivoted, rotating supports to shift the device toward its intended target. These devices, some as large and awkward as a piece of heavy luggage, are subject to the same issues confronted by mechanical parts: Components rub, wear out, and get stuck. The poor reliability and bulk not to mention the power requirements to run one of the machines have made mechanical beam steering components less than ideal for use in applications where weight, bulk, and maneuverability are prime concerns, such as on an unmanned aerial vehicle (UAV) or a microscope. The solution to developing reliable, lighter weight, nonmechanical steering methods to replace the hefty steering boxes was to think outside the box, and a NASA research partner did just that by developing a new beam steering method that bends and redirects the beam, as opposed to shifting the entire apparatus. The benefits include lower power requirements, a smaller footprint, reduced weight, and better control and flexibility in steering capabilities. Such benefits are realized without sacrificing aperture size, efficiency, or scanning range, and can be applied to myriad uses: propulsion systems, structures, radiation protection systems, and landing systems.

Effects of heavy weight waste glass recycled as fine aggregate on the mechanical properties of mortar specimens

International Nuclear Information System (INIS)

Choi, So Yeong; Choi, Yoon Suk; Yang, Eun Ik

2017-01-01

Highlights: • The properties of mortar used heavy weight waste glass as fine aggregate were compared. • Unit volume weight and shielding performance increased with the content of waste glass. • However, the strength decreased as the waste glass substitution increased. • The waste glass substitution affected on pores ranging from 10–100 nm. - Abstract: The quantities of heavy weight waste glass have increased over time due to rapid industrialization and changes in the quality of life. Moreover, most of this waste is not recycled. Concrete is the most widely used construction material, the huge amounts of natural resources are required to make concrete. Therefore, it is necessary to investigate the possibility of recycling of heavy weight waste glass as an ingredient in the manufacturing of concrete. In this study, the suitability of heavy weight waste glass as a fine aggregate material is considered. The results of flow test, unit volume weight, radiation shielding performance, compressive strength, flexural strength, and micropore and macropore distribution of mortar are compared and evaluated. It was found that when the heavy weight waste glass substitution ratio increases, the fluidity, unit volume weight and radiation shielding performance also increase. However, the compressive and flexural strength of mortar gradually decrease with an increase in the substitution ratio of heavy weight waste glass. Moreover, the micro pore size distribution is significantly affected by the substitution of heavy weight waste glass.

Bond strength of a pit-and-fissure sealant associated to etch-and-rinse and self-etching adhesive systems to saliva-contaminated enamel: individual vs. simultaneous light curing.

Science.gov (United States)

Gomes-Silva, Jaciara Miranda; Torres, Carolina Paes; Contente, Marta Maria Martins Giamatei; Oliveira, Maria Angélica Hueb de Menezes; Palma-Dibb, Regina Guenka; Borsatto, Maria Cristina

2008-01-01

This study evaluated in vitro the shear bond strength (SBS) of a resin-based pit-and-fissure sealant [Fluroshield (F), Dentsply/Caulk] associated with either an etch-and-rinse [Adper Single Bond 2 (SB), 3M/ESPE] or a self-etching adhesive system [Clearfil S3 Bond (S3), Kuraray Co., Ltd.] to saliva-contaminated enamel, comparing two curing protocols: individual light curing of the adhesive system and the sealant or simultaneous curing of both materials. Mesial and distal enamel surfaces from 45 sound third molars were randomly assigned to 6 groups (n=15), according to the bonding technique: I - F was applied to 37% phosphoric acid etched enamel. The other groups were contaminated with fresh human saliva (0.01 mL; 10 s) after acid etching: II - SB and F were light cured separately; III - SB and F were light cured together; IV - S3 and F were light cured separately; V - S3 and F were light cured simultaneously; VI - F was applied to saliva-contaminated, acid-etched enamel without an intermediate bonding agent layer. SBS was tested to failure in a universal testing machine at 0.5 mm/min. Data were analyzed by one-way ANOVA and Fisher's test (alpha=0.05).The debonded specimens were examined with a stereomicroscope to assess the failure modes. Three representative specimens from each group were observed under scanning electron microscopy for a qualitative analysis. Mean SBS in MPa were: I-12.28 (+/-4.29); II-8.57 (+/-3.19); III-7.97 (+/-2.16); IV-12.56 (+/-3.11); V-11.45 (+/-3.77); and VI-7.47 (+/-1.99). In conclusion, individual or simultaneous curing of the intermediate bonding agent layer and the resin sealant did not seem to affect bond strength to saliva-contaminated enamel. S3/F presented significantly higher SBS than the that of the groups treated with SB etch-and-rinse adhesive system and similar SBS to that of the control group, in which the sealant was applied under ideal dry, noncontaminated conditions.

Using of Porcelinite as Coarse Aggregate in Concrete

Directory of Open Access Journals (Sweden)

Haifa Saleh

2015-02-01

Full Text Available In this research the ability of using porcelinite as coarse aggregate to produce light weight concrete was investigated.  The experimental program consists of preparing and testing a mixes to investigate mechanical properties of concrete, with a total of 15 cubes (100×100×100 mm, 30 cylinders (100×200 mm. The tests include compressive strength, splitting tensile strength, fresh and hardened density of  light weight concrete for different porcelinite percentages ranged between(0% to 100% of the coarse aggregate weight. The obtained results for tested specimens were compared to control one. Test results indicated that using of porcelinite in concrete mix reduces the strength of concrete Porcelinite aggregate represents a reduction in density ranging between (10%-36% of normal weight concrete, therefore there is an advantage  using this type of light weight aggregate in this country where soil bearing capacity is low in most construction sites.

Enhancing the compressive strength of landfill soil using cement and bagasse ash

Science.gov (United States)

Azim, M. A. M.; Azhar, A. T. S.; Tarmizi, A. K. A.; Shahidan, S.; Nabila, A. T. A.

2017-11-01

The stabilisation of contaminated soil with cement and agricultural waste is a widely applied method which contributes to the sustainability of the environment. Soil may be stabilised to increase strength and durability or to prevent erosion and other geotechnical failure. This study was carried out to evaluate the compressive strength of ex-landfill soil when cement and bagasse ash (BA) are added to it. Different proportions of cement (5%, 10%, 15% and 20%) was added to sample weights without BA. On the other hand, the cement in a different batch of sample weights was replaced by 2.5%, 5%, 7.5% and 10% of BA. All samples were allowed to harden and were cured at room temperature for 7, 14 and 28 days respectively. The strength of the contaminated soil was assessed using an unconfined compressive strength test (UCS). The laboratory tests also included the index properties of soil, cement and bagasse ash in raw form. The results indicated that the samples with cement achieved the highest compressive strength measuring 4.39 MPa. However, this study revealed that the use of bagasse ash produced low quality products with a reduction in strength. For example, when 5% of cement was replaced with 5% ash, the compressive strength decreased by about 54% from 0.72 MPa to 0.33 MPa. Similarly, the compressive strength of each sample after a curing period of 28 days was higher compared to samples cured for 7 and 14 days respectively. This is proved that a longer curing period is needed to increase the compressive strength of the samples.

Weight-training injuries. Common injuries and preventative methods.

Science.gov (United States)

Mazur, L J; Yetman, R J; Risser, W L

1993-07-01

The use of weights is an increasingly popular conditioning technique, competitive sport and recreational activity among children, adolescents and young adults. Weight-training can cause significant musculoskeletal injuries such as fractures, dislocations, spondylolysis, spondylolisthesis, intervertebral disk herniation, and meniscal injuries of the knee. Although injuries can occur during the use of weight machines, most apparently happen during the aggressive use of free weights. Prepubescent and older athletes who are well trained and supervised appear to have low injury rates in strength training programmes. Good coaching and proper weightlifting techniques and other injury prevention methods are likely to minimise the number of musculoskeletal problems caused by weight-training.

The Importance of Muscular Strength: Training Considerations.

Science.gov (United States)

Suchomel, Timothy J; Nimphius, Sophia; Bellon, Christopher R; Stone, Michael H

2018-04-01

This review covers underlying physiological characteristics and training considerations that may affect muscular strength including improving maximal force expression and time-limited force expression. Strength is underpinned by a combination of morphological and neural factors including muscle cross-sectional area and architecture, musculotendinous stiffness, motor unit recruitment, rate coding, motor unit synchronization, and neuromuscular inhibition. Although single- and multi-targeted block periodization models may produce the greatest strength-power benefits, concepts within each model must be considered within the limitations of the sport, athletes, and schedules. Bilateral training, eccentric training and accentuated eccentric loading, and variable resistance training may produce the greatest comprehensive strength adaptations. Bodyweight exercise, isolation exercises, plyometric exercise, unilateral exercise, and kettlebell training may be limited in their potential to improve maximal strength but are still relevant to strength development by challenging time-limited force expression and differentially challenging motor demands. Training to failure may not be necessary to improve maximum muscular strength and is likely not necessary for maximum gains in strength. Indeed, programming that combines heavy and light loads may improve strength and underpin other strength-power characteristics. Multiple sets appear to produce superior training benefits compared to single sets; however, an athlete's training status and the dose-response relationship must be considered. While 2- to 5-min interset rest intervals may produce the greatest strength-power benefits, rest interval length may vary based an athlete's training age, fiber type, and genetics. Weaker athletes should focus on developing strength before emphasizing power-type training. Stronger athletes may begin to emphasize power-type training while maintaining/improving their strength. Future research should

Light intensity physical activity and sedentary behavior in relation to body mass index and grip strength in older adults: cross-sectional findings from the Lifestyle Interventions and Independence for Elders (LIFE) study

Science.gov (United States)

Background: Identifying modifiable determinants of fat mass and muscle strength in older adults is important given their impact on physical functioning and health. Light intensity physical activity and sedentary behavior are potential determinants, but their relations to these outcomes are poorly un...

Determination of the second virial coefficient of bovine serum albumin under varying pH and ionic strength by composition-gradient multi-angle static light scattering.

Science.gov (United States)

Ma, Yingfang; Acosta, Diana M; Whitney, Jon R; Podgornik, Rudolf; Steinmetz, Nicole F; French, Roger H; Parsegian, V Adrian

2015-01-01

Composition-gradient multi-angle static light scattering (CG-MALS) is an emerging technique for the determination of intermolecular interactions via the second virial coefficient B22. With CG-MALS, detailed studies of the second virial coefficient can be carried out more accurately and effectively than with traditional methods. In addition, automated mixing, delivery and measurement enable high speed, continuous, fluctuation-free sample delivery and accurate results. Using CG-MALS we measure the second virial coefficient of bovine serum albumin (BSA) in aqueous solutions at various values of pH and ionic strength of a univalent salt (NaCl). The systematic variation of the second virial coefficient as a function of pH and NaCl strength reveals the net charge change and the isoelectric point of BSA under different solution conditions. The magnitude of the second virial coefficient decreases to 1.13 x 10(-5) ml*mol/g(2) near the isoelectric point of pH 4.6 and 25 mM NaCl. These results illuminate the role of fundamental long-range electrostatic and van der Waals forces in protein-protein interactions, specifically their dependence on pH and ionic strength.

Ketogenic diet does not affect strength performance in elite artistic gymnasts

Directory of Open Access Journals (Sweden)

Paoli Antonio

2012-07-01

Full Text Available Abstract Background Despite the increasing use of very low carbohydrate ketogenic diets (VLCKD in weight control and management of the metabolic syndrome there is a paucity of research about effects of VLCKD on sport performance. Ketogenic diets may be useful in sports that include weight class divisions and the aim of our study was to investigate the influence of VLCKD on explosive strength performance. Methods 8 athletes, elite artistic gymnasts (age 20.9 ± 5.5 yrs were recruited. We analyzed body composition and various performance aspects (hanging straight leg raise, ground push up, parallel bar dips, pull up, squat jump, countermovement jump, 30 sec continuous jumps before and after 30 days of a modified ketogenic diet. The diet was based on green vegetables, olive oil, fish and meat plus dishes composed of high quality protein and virtually zero carbohydrates, but which mimicked their taste, with the addition of some herbal extracts. During the VLCKD the athletes performed the normal training program. After three months the same protocol, tests were performed before and after 30 days of the athletes’ usual diet (a typically western diet, WD. A one-way Anova for repeated measurements was used. Results No significant differences were detected between VLCKD and WD in all strength tests. Significant differences were found in body weight and body composition: after VLCKD there was a decrease in body weight (from 69.6 ± 7.3 Kg to 68.0 ± 7.5 Kg and fat mass (from 5.3 ± 1.3 Kg to 3.4 ± 0.8 Kg p  Conclusions Despite concerns of coaches and doctors about the possible detrimental effects of low carbohydrate diets on athletic performance and the well known importance of carbohydrates there are no data about VLCKD and strength performance. The undeniable and sudden effect of VLCKD on fat loss may be useful for those athletes who compete in sports based on weight class. We have demonstrated that using VLCKD for a

Ketogenic diet does not affect strength performance in elite artistic gymnasts.

Science.gov (United States)

Paoli, Antonio; Grimaldi, Keith; D'Agostino, Dominic; Cenci, Lorenzo; Moro, Tatiana; Bianco, Antonino; Palma, Antonio

2012-07-26

Despite the increasing use of very low carbohydrate ketogenic diets (VLCKD) in weight control and management of the metabolic syndrome there is a paucity of research about effects of VLCKD on sport performance. Ketogenic diets may be useful in sports that include weight class divisions and the aim of our study was to investigate the influence of VLCKD on explosive strength performance. 8 athletes, elite artistic gymnasts (age 20.9 ± 5.5 yrs) were recruited. We analyzed body composition and various performance aspects (hanging straight leg raise, ground push up, parallel bar dips, pull up, squat jump, countermovement jump, 30 sec continuous jumps) before and after 30 days of a modified ketogenic diet. The diet was based on green vegetables, olive oil, fish and meat plus dishes composed of high quality protein and virtually zero carbohydrates, but which mimicked their taste, with the addition of some herbal extracts. During the VLCKD the athletes performed the normal training program. After three months the same protocol, tests were performed before and after 30 days of the athletes' usual diet (a typically western diet, WD). A one-way Anova for repeated measurements was used. No significant differences were detected between VLCKD and WD in all strength tests. Significant differences were found in body weight and body composition: after VLCKD there was a decrease in body weight (from 69.6 ± 7.3 Kg to 68.0 ± 7.5 Kg) and fat mass (from 5.3 ± 1.3 Kg to 3.4 ± 0.8 Kg p < 0.001) with a non-significant increase in muscle mass. Despite concerns of coaches and doctors about the possible detrimental effects of low carbohydrate diets on athletic performance and the well known importance of carbohydrates there are no data about VLCKD and strength performance. The undeniable and sudden effect of VLCKD on fat loss may be useful for those athletes who compete in sports based on weight class. We have demonstrated that using VLCKD for a relatively

Light Responsive Polymer Membranes: A Review

Directory of Open Access Journals (Sweden)

Fiore Pasquale Nicoletta

2012-03-01

Full Text Available In recent years, stimuli responsive materials have gained significant attention in membrane separation processes due to their ability to change specific properties in response to small external stimuli, such as light, pH, temperature, ionic strength, pressure, magnetic field, antigen, chemical composition, and so on. In this review, we briefly report recent progresses in light-driven materials and membranes. Photo-switching mechanisms, valved-membrane fabrication and light-driven properties are examined. Advances and perspectives of light responsive polymer membranes in biotechnology, chemistry and biology areas are discussed.

Aggregate effects on γ-ray shielding characteristics and compressive strength on concrete

International Nuclear Information System (INIS)

Oh, Jeong Hwan; Choi, Soo Seok; Mun, Young Bun; Lee, Jae Hyung; Choi, Hyun Kook

2016-01-01

We observed the γ-ray shielding characteristics and compressive strength of five types of concrete using general aggregates and high-weight aggregates. The aggregates were classified into fine aggregate and coarse aggregate according to the average size. The experimental results obtained an attenuation coefficient of 0.371 cm-1 from a concrete with the oxidizing slag sand (OSS) and oxidizing slag gravel (OSG) for a γ-ray of "1"3"7Cs, which is improved by 2% compared with a concrete with typical aggregates of sand and gravel. In the unit weight measurement, a concrete prepared by iron ore sand (IOS) and OSG had the highest value of 3,175 kg·m"-"3. Although the unit weight of the concrete with OSS and OSG was 3,052 kg·m"-"3, which was lower than the maximum unit weight condition by 123 kg·m"-"3, its attenuation coefficient was improved by 0.012 cm-1. The results of chemical analysis of aggregates revealed that the magnesium content in oxidizing slag was lower than that in iron ore, while the calcium content was higher. The concrete with oxidizing slag aggregates demonstrated enhanced γ-ray shielding performance due to a relatively high calcium content compared with the concrete with OSS and OSG in spite of a low unit weight. All sample concretes mixed with high-weight aggregates had higher compressive strength than the concrete with typical sand and gravel. When OSS and IOS were used, the highest compressive strength was 50.2 MPa, which was an improvement by 45% over general concrete, which was achieved after four weeks of curing

Aggregate effects on γ-ray shielding characteristics and compressive strength on concrete

Energy Technology Data Exchange (ETDEWEB)

Oh, Jeong Hwan; Choi, Soo Seok [Jeju National University, Jeju (Korea, Republic of); Mun, Young Bun; Lee, Jae Hyung; Choi, Hyun Kook [Sungshin Cement Co., Ltd, Sejong (Korea, Republic of)

2016-12-15

We observed the γ-ray shielding characteristics and compressive strength of five types of concrete using general aggregates and high-weight aggregates. The aggregates were classified into fine aggregate and coarse aggregate according to the average size. The experimental results obtained an attenuation coefficient of 0.371 cm-1 from a concrete with the oxidizing slag sand (OSS) and oxidizing slag gravel (OSG) for a γ-ray of {sup 137}Cs, which is improved by 2% compared with a concrete with typical aggregates of sand and gravel. In the unit weight measurement, a concrete prepared by iron ore sand (IOS) and OSG had the highest value of 3,175 kg·m{sup -3}. Although the unit weight of the concrete with OSS and OSG was 3,052 kg·m{sup -3}, which was lower than the maximum unit weight condition by 123 kg·m{sup -3}, its attenuation coefficient was improved by 0.012 cm-1. The results of chemical analysis of aggregates revealed that the magnesium content in oxidizing slag was lower than that in iron ore, while the calcium content was higher. The concrete with oxidizing slag aggregates demonstrated enhanced γ-ray shielding performance due to a relatively high calcium content compared with the concrete with OSS and OSG in spite of a low unit weight. All sample concretes mixed with high-weight aggregates had higher compressive strength than the concrete with typical sand and gravel. When OSS and IOS were used, the highest compressive strength was 50.2 MPa, which was an improvement by 45% over general concrete, which was achieved after four weeks of curing.

Influence of pre-pregnancy leisure time physical activity on gestational and postpartum weight gain and birth weight

DEFF Research Database (Denmark)

Hegaard, Hanne Kristine; Rode, Line; Katballe, Malene Kjær

2017-01-01

In order to examine the association between pre-pregnancy leisure time physical activities and gestational weight gain, postpartum weight gain and birth weight, we analysed prospectively collected data from 1827 women with singleton term pregnancies. Women were categorised in groups of sedentary...... risk of having a gestational weight gain above Institute of Medicine (IOM) recommendations with an odds ratio of 2.60 (1.32-5.15) compared to light exercisers. However, birth weight and one year postpartum weight was similar for all four groups. Thus, although competitive athletes gain more weight than...... recommended during pregnancy, this may not affect birth weight or postpartum weight. Impact statement: What is already known on this subject: Previous studies have found that increased pre-pregnancy physical activity is associated with lower gestational weight gain during the last trimester, but showed...

Small Worldness in Dense and Weighted Connectomes

Science.gov (United States)

Colon-Perez, Luis; Couret, Michelle; Triplett, William; Price, Catherine; Mareci, Thomas

2016-05-01

The human brain is a heterogeneous network of connected functional regions; however, most brain network studies assume that all brain connections can be described in a framework of binary connections. The brain is a complex structure of white matter tracts connected by a wide range of tract sizes, which suggests a broad range of connection strengths. Therefore, the assumption that the connections are binary yields an incomplete picture of the brain. Various thresholding methods have been used to remove spurious connections and reduce the graph density in binary networks. But these thresholds are arbitrary and make problematic the comparison of networks created at different thresholds. The heterogeneity of connection strengths can be represented in graph theory by applying weights to the network edges. Using our recently introduced edge weight parameter, we estimated the topological brain network organization using a complimentary weighted connectivity framework to the traditional framework of a binary network. To examine the reproducibility of brain networks in a controlled condition, we studied the topological network organization of a single healthy individual by acquiring 10 repeated diffusion-weighted magnetic resonance image datasets, over a one-month period on the same scanner, and analyzing these networks with deterministic tractography. We applied a threshold to both the binary and weighted networks and determined that the extra degree of freedom that comes with the framework of weighting network connectivity provides a robust result as any threshold level. The proposed weighted connectivity framework provides a stable result and is able to demonstrate the small world property of brain networks in situations where the binary framework is inadequate and unable to demonstrate this network property.

A Strength Training Program for Primary Care Patients, Central Pennsylvania, 2012

Science.gov (United States)

Patel, Vijay A.; Kraschnewski, Jennifer L.; Rovniak, Liza S.; Messina, Dino A.; Stuckey, Heather L.; Curry, William J.; Chuang, Cynthia H.; Sherwood, Lisa L.; Hess, Stacy L.

2014-01-01

Introduction Primary care providers can recommend strength training programs to use “Exercise as Medicine,” yet few studies have examined the interest of primary care patients in these programs. Methods We conducted a cross-sectional survey of primary care patients in central Pennsylvania. Interest in participating in free group-based strength training and weight control programs was assessed, in addition to patient demographics, medical history, and quality of life. Results Among 414 patients, most (61.0%) were aged 54 or older, and 64.0% were female. More patients were interested in a strength training program (55.3%) than in a weight control program (45.4%). Nearly three-quarters (72.8%) of those reporting 10 or more days of poor physical health were interested in a strength training program compared with 49.5% of those reporting no days of poor physical health. After adjusting for potential confounders, those reporting poorer physical health had 2.7 greater odds (95% confidence interval, 1.4–5.1) of being interested in a strength training program compared with those reporting better physical health. Patients with hypertension, diabetes, or high cholesterol were not more interested in a strength training program than those without these conditions. Conclusion Primary care practices may consider offering or referring patients to community-based strength training programs. This study observed high levels of interest in these widely available programs. Practices may also consider screening and referring those with poorer physical health, as they may be the most interested and have the most to gain from participating. PMID:24967829

Relating wood properties to handsheet porosity and mechanical strength

CSIR Research Space (South Africa)

Maharaj, S

2006-11-01

Full Text Available , 4041 3CSIR, Forestry and Forest Products Research Centre, P.O. Box 17001, Congella, 4013 WOOD HAND-SHEET (STRENGTH) PROCESSING Anatomy Chemistry Density Tear Tensile Burst Background Variation in pulp mills •Need to predict quality of end... important concepts… Some important concepts… • Collapsibility and inter-fibre bonding Light Microscopy SEM • Tear – Fibre level: pull-out vs. breaking/rupture Some important concepts… •Fibre breakage / rupture: less energy = lower tear strength...

Changes in Maximal Strength, Velocity, and Power After 8 Weeks of Training With Pneumatic or Free Weight Resistance.

Science.gov (United States)

Frost, David M; Bronson, Stefanie; Cronin, John B; Newton, Robert U

2016-04-01

Because free weight (FW) and pneumatic (PN) resistance are characterized by different inertial properties, training with either resistance could afford unique strength, velocity, and power adaptations. Eighteen resistance-trained men completed baseline tests to determine their FW and PN bench press 1 repetition maximum (1RM). During the FW session, 4 explosive repetitions were performed at loads of 15, 30, 45, 60, 75, and 90% 1RM to assess force, velocity, and power. Participants were then assigned to a FW or PN training group, which involved three 90-minute sessions per week for 8 weeks. Both intervention groups completed identical periodized programs with the exception of the resistance used to perform all bench press movements. Free weight participants significantly increased their FW and PN 1RM (10.4 and 9.4%), and maximum (any load) force (9.8%), velocity (11.6%), and power (22.5%). Pneumatic-trained participants also exhibited increases in FW and PN 1RM (11.6 and 17.5%), and maximum force (8.4%), velocity (13.6%), and power (33.4%). Both interventions improved peak barbell velocity at loads of 15 and 30% 1RM; however, only the PN-trained individuals displayed improvements in peak force and power at these same loads. Training with PN resistance may offer advantages if attempting to improve power at lighter relative loads by affording an opportunity to consistently achieve higher accelerations and velocities (F = ma), in comparison with FW. Exploiting the inertial properties of the resistance, whether mass, elastic or PN, could afford an opportunity to develop mixed-method training strategies and/or elicit unique neuromuscular adaptations to suit the specific needs of athletes from sports characterized by varying demands.

Effects of strength training program on hip extensors and knee extensors strength of lower limb in children with spastic diplegic cerebral palsy.

Science.gov (United States)

Aye, Thanda; Thein, Soe; Hlaing, Thaingi

2016-01-01

[Purpose] The purpose of this study was to determine whether strength training programs for hip extensors and knee extensors improve gross motor function of children with cerebral palsy in Myanmar. [Subjects and Methods] Forty children (25 boys and 15 girls, mean age: 6.07 ± 2.74 years) from National Rehabilitation Hospital, Yangon, Myanmar, who had been diagnosed with spastic diplegic cerebral palsy, Gross Motor Classification System I and II participated in a 6-week strength training program (45 minutes per day, 3 days per week) on hip and knee extensors. Assessment was made, before and after intervention, of the amount of training weight in pounds, as well as Gross Motor Function Measure (GMFM) dimensions D (standing) and E (walking, running, jumping). [Results] All scores had increased significantly after the strength-training program. [Conclusion] A simple method of strength-training program for hip and knee extensors might lead to improved muscle strength and gross motor function in children with spastic diplegic cerebral palsy.

Strength distributions of electromagnetic transitions in light nuclei

International Nuclear Information System (INIS)

Kostin, V.Ya.; Koval', A.A.; Kopanets, E.G.; Tsytko, S.P.

1980-01-01

Distributions of probabilities of electromagnetic transitions from resonance levels of light nuclei with masses A=Z-40 for eight types of transition (epsilon1, epsilon2, M1, M8, isoscalar and isovector) are obtained. Recommended upper limits (RUL) of transition probabilities are determined for each type of transitions. A comparison with analogous characteristics for transitions between bound states is carried out. It has been causes found that RUL for resonance states substantially differ from RUL for transitions between bound states. Possible causes of such difference are discussed

Tensile strength of AK7 alloy after treatment by exothermic mixtures

International Nuclear Information System (INIS)

Lipinski, T.

2002-01-01

The paper presents the influence of treatment by chemical compounds giving exothermic effect on the tensile strength of AK7 alloy. The research was carried out on 1100 g of the alloy in classical mould. The chemical mixture was composed of Na 2 B 4 O 7 , NaNO 3 and Cr 2 O 3 + AlNi. The studies were conducted following a mathematical experiment plan. The action of Borax was free from interference whereas the two residual constituents were mass-dependence. Excess NaNO 3 was caused by the reduction of the value of the tensile strength. Cr 2 O 3 + AlNi strengthened the influence of NaNO 3 . It was found that the blending of Na 2 B 4 O 7 and NaNO 3 on weight ratio 1,5 to 1 and of NaNO 3 and Cr 2 O 3 + AlNi on weight ratio 1 to 3 improved the tensile strength of the AK7 alloy after treatment. (author)

Neutron strength functions: the link between resolved resonances and the optical model

International Nuclear Information System (INIS)

Moldauer, P.A.

1980-01-01

Neutron strength functions and scattering radii are useful as energy and channel radius independent parameters that characterize neutron scattering resonances and provide a connection between R-matrix resonance analysis and the optical model. The choice of R-matrix channel radii is discussed, as are limitations on the accuracies of strength functions. New definitions of the p-wave strength function and scattering radius are proposed. For light nuclei, where strength functions display optical model energy variations over the resolved resonances, a doubly reduced partial neutron width is introduced for more meaningful statistical analyses of widths. The systematic behavior of strength functions and scattering radii is discussed

A Progressive Resistance Weight Training Program Designed to Improve the Armor Crewman’s Strength

Science.gov (United States)

1992-06-05

Training with a weightlifting belt which supports the abdominal region and lower back can help reduce the chance for injury . A belt 35 should be used...life-saving task more efficiently. If the wounded or unconscious crewman has a traumatic injury , extreme care must be taken not to cause further... injury . This justifies the need for added strength. Three strength related maintenance tasks routinely performed are: (1) checking the link assembly, (2

Comparison of body weight-supported treadmill training versus body weight-supported overground training in people with incomplete tetraplegia: a pilot randomized trial.

Science.gov (United States)

Senthilvelkumar, Thangavelu; Magimairaj, Henry; Fletcher, Jebaraj; Tharion, George; George, Jacob

2015-01-01

To compare the effectiveness of body weight-supported treadmill training and body weight-supported overground training for improving gait and strength in people with traumatic incomplete tetraplegia. Assessor blinded randomized trial. Rehabilitation institute of a tertiary care teaching hospital in India. Sixteen participants with traumatic motor incomplete tetraplegia and within two years of injury. Participants were randomised to one of two groups: body weight-supported overground training on level ground and body weight-supported treadmill training. Both groups received 30 minutes of gait training per day, five days a week for eight weeks. In addition, both groups received regular rehabilitation which included flexibility, strength, balance, self care and functional training. The primary outcome measure was the Walking Index for Spinal Cord Injury (/20 points) and the secondary outcome was the Lower Extremity Muscle Score (/50 points). There was no statistically significant between group differences in the Walking Index for Spinal Cord Injury [mean difference=0.3points; 95% CI (-4.8 to 5.4); p=0.748] or the Lower Extremity Muscle Score [mean difference=0.2 points; 95% CI (-3.8 to 5.1); p=0.749]. Gait training with body weight-supported overground training is comparable to treadmill training for improving locomotion in people with traumatic incomplete tetraplegia. © The Author(s) 2014.

Design of duplex low carbon steels for improved strength: weight applications

Energy Technology Data Exchange (ETDEWEB)

Koo, J.

1977-08-01

Duplex ferrite-martensite (DFM) steels with excellent combinations of strength and formability have been selected from first principles, and their microstructure-property relationships established through a systematic investigation of a series of ternary Fe/X/0.1 C steels (X being varying amount of Cr and Si). Duplex processing consists of initial austenitization and quenching to form 100% martensite, followed by annealing in the (..cap alpha.. + ..gamma..) range and subsequent quenching. The resultant DFM morphology is controlled by the type and amount of alloying element X.

The effect of air thinning on dentin adhesive bond strength.

Science.gov (United States)

Hilton, T J; Schwartz, R S

1995-01-01

The purpose of this study was to determine if air thinning three dentin adhesives would affect bond strength to dentin. Ninety human molars were mounted in acrylic and the occlusal surfaces ground to expose a flat dentin surface. Thirty teeth were randomly assigned to one of the following dentin bonding agent/composite combinations: A) Universal Bond 3/TPH (Caulk), B) All-Bond 2/Bis-Fil-P (Bisco), and C) Scotchbond Multi-Purpose/Z-100 (3m). The primers were applied following the manufacturers' instructions. The adhesives were applied by two methods. A thin layer of adhesive was applied with a brush to 15 specimens in each group and light cured. Adhesive was brushed on to the remaining 15 teeth in the group, air thinned for 3 seconds, and then polymerized. The appropriate composite was applied in 2 mm increments and light cured utilizing a 5 mm-in-diameter split Teflon mold. Following 3 months of water storage, all groups were shear tested to failure on an Instron Universal Testing Machine. Bond strength was significantly higher in all groups when the dentin bonding agent was painted on without being air thinned. Scotchbond Multi-Purpose had significantly higher bond strength than All-Bond 2, which had significantly higher bond strength than Universal Bond 3.

Body Composition, Muscular Strength and Bone Status among Undernourished Children in Malaysia

International Nuclear Information System (INIS)

Chong, Kar Hau; Poh, Bee Koon

2014-01-01

Full text: Despite significant advances in social and economic development, undernutrition remains a devastating public health problem that affects millions of children across the globe, particularly in developing nations. It is important to understand how changes in nutritional status affect physical health and function, so that undernutrition-related alterations can be identified and interpreted correctly. This paper aimed to determine the impact of undernutrition in children through the assessment of three nutrition-related indicators: body composition, muscular strength and bone status. This study is part of the Nutrition Survey of Malaysian Children, which is part of the four-country South East Asian Nutrition Surveys (SEANUTS). A total of 208 school children (102 boys, 106 girls) in the age range of 7 to 10 years were included in this analysis, of which 104 were underweight (WAZ<-2SD) and 104 were normal-weight group (-2SD≤WAZ≤+2SD), individually-matched for sex, age, and ethnicity. Anthropometric measurements included weight and height; and body composition was measured by bioelectrical impedance analysis. Muscular strength of both hands was assessed independently by hand-held dynamometer. Bone status was evaluated using a radial quantitative ultrasound system at one-third distal radius of the non-dominant hand. Anthropometric measurements and bone status were not significantly different between the sexes. Boys had significantly higher muscular strength and lean mass (p<0.05), but lower fat mass when compared to the girls (p<0.01). In both sexes, the undernourished group presented significantly lower anthropometric and body composition measurements and muscular strength than their normal-weight counterparts (p<0.001). However, no significant differences were observed for bone status between the two weight groups in boys (p = 0.09) and girls (p = 0.98). These findings imply that undernutrition can have profound negative impact on body composition as well

Passive beam sprending systems and light-weight gentries for synchrotron based hadron therapy

International Nuclear Information System (INIS)

Maier, A.

1998-12-01

Hadron therapy is a promising technique that uses beams of protons or light ions for the treatment of cancer. In order to open this technique to a wider application, dedicated hospital based treatment centers are now needed. The Proton-Ion Medical Machine Study (PIMMS) in CERN is concerned with the design of such a center that would use both protons and light ions. The dual species operation makes it preferable to base the center on a synchrotron. The present thesis is concerned with the beam delivery for the protons. After introducing the basic vocabulary of linear beam optics, the feasibility of a light-weight gantry with passive beam spreading fed by a synchrotron is investigated. The device is a non-linear magnetic structure, which can be described as a magnetic guide or as a proton pipe. Detailed studies show that while it is possible to design an optically stable 270 o section, which would be necessary for a gantry, the properties do not fulfil the requirements of a gantry for medical purposes. It was therefore concluded that a conventional isocentric gantry would be used for protons. The problem of passive beam-spreading is also investigated. A detailed knowledge of multiple scattering is necessary for the design of such a system. The basic principles of multiple scattering following Moliere's theory are mentioned. In addition, a Gaussian approximation of multiple scattering developed by Highland is described. A treatment of multiple scattering for thick and thin scatterers is then developed using the so-called Q-formalism that is frequently used in accelerator optics. This is then used to give a statistical description of the beam with scattering included using the Twiss formalism that is also used widely in accelerator physics. Excellent agreement is demonstrated with Monte-Carlo data. The Twiss-Scatterer relations obtained make it possible to include arbitrary, thick scatterers in accelerator codes. High intensities for protons are less readily available

Heavyweight cement concrete with high stability of strength parameters

Science.gov (United States)

Kudyakov, Konstantin; Nevsky, Andrey; Danke, Ilia; Kudyakov, Aleksandr; Kudyakov, Vitaly

2016-01-01

The present paper establishes regularities of basalt fibers distribution in movable cement concrete mixes under different conditions of their preparation and their selective introduction into mixer during the mixing process. The optimum content of basalt fibers was defined as 0.5% of the cement weight, which provides a uniform distribution of fibers in the concrete volume. It allows increasing compressive strength up to 51.2% and increasing tensile strength up to 28.8%. Micro-structural analysis identified new formations on the surface of basalt fibers, which indicates the good adhesion of hardened cement paste to the fibers. Stability of concrete strength parameters has significantly increased with introduction of basalt fibers into concrete mix.

Bond strength of compomers to dentin using acidic primers.

Science.gov (United States)

Tate, W H; You, C; Powers, J M

1999-10-01

To determine the in vitro bond strengths of seven compomer/bonding agent restorative systems to human dentin. Seven compomer/bonding agents were bonded to human dentin, stored in water at 37 degrees C for 24 hours, and debonded in tension. Bonding conditions were with and without phosphoric acid etching, with and without the use of combined primer/bonding agents, and under moist and wet bond interfaces. Without phosphoric acid etching, F2000/F2000 Compomer Primer/Adhesive and F2000/Single Bond Dental Adhesive System were less sensitive to dentin wetness. With moist dentin, bond strengths of Dyract/Prime & Bond 2.1, Dyract AP/Prime & Bond 2.1, Hytac/OSB light-curing, one-component bonding agent, F2000/Single Bond, and Freedom/STAE single component light-cured dentin/enamel adhesive system, were improved with phosphoric acid etching. Also, with moist dentin, the bond strength of F2000/F2000 Compomer Primer/Adhesive in the 3M Clicker dispensing system was higher without phosphoric acid etching, whereas bonds of Compoglass/Syntac Single-component were not affected by phosphoric acid etching. Bonding did not occur without primer/bonding agent, regardless of surface condition or use of phosphoric acid etching.

Mechanical characteristics of connection for GFRP plates using tapping screws

Science.gov (United States)

Inoue, Yuya; Duong, Nguyen Ngoc; Satake, Chito; Matsumoto, Yukihiro

2017-10-01

FRP material has good characteristics such as light-weight, high-strength and high-corrosion resistance. Light-weight structure possesses some advantages over the rational constructing procedure such as self-building structures. In recent years, mechanical characteristics of FRP joints using bolts and/or rivet are investigated in detail, and they are used in many FRP structures. However, the bolts lack bearing strength compared with material strength and the joint needs the prepared bolt hole. In this paper, an alternative joint system for FRP structures using tapping screw is proposed and mechanical characteristics are investigated through experiment. Tapping screw has some advantages; easy-to-use, light-weight and high bearing strength. Then, the results of double-lapped tensile shear tests having one, four and eight tapping screws along longitudinal direction are shown. Moreover, it is shown that longitudinal stress distribution is approximately corresponding to the theoretical stress distribution of double-lapped adhesively bonded joints. Based on these, it is proposed that joint strength can be estimated by using the present calculation method.

Effect of molecular weight and testing rate on adhesion property of pressure-sensitive adhesives prepared from epoxidized natural rubber

International Nuclear Information System (INIS)

Khan, Imran; Poh, B.T.

2011-01-01

Research highlights: → Elucidation of adhesion property of epoxidized natural rubber (ENR 25). → Correlation of peel and shear strength with molecular weight and rate of testing. → Confirmation of miscibility of tackifier and ENR 25 by DSC and FTIR study. → Applicability of Fox equation in ENR 25/coumarone-indene resin system. -- Abstract: The dependence of peel strength and shear strength of epoxidized natural rubber (ENR 25)-based pressure-sensitive adhesive on molecular weight and rate of testing was investigated using coumarone-indene as the tackifying resin. Toluene and polyethylene terephthalate (PET) were used as the solvent and substrate respectively throughout the study. A SHEEN hand coater was used to coat the adhesive on the substrate at a coating thickness of 120 μm. All the adhesion properties were determined by a Llyod Adhesion Tester operating at different rates of testing. Result shows that peel strength and shear strength increases up to an optimum molecular weight of 6.5 x 10 4 of ENR 25. For peel strength, the observation is attributed to the combined effects of wettability and mechanical strength of rubber at the optimum molecular weight, whereas for the shear strength, it is ascribed to the increasing amount of adhesive present in the coating layer which enhances the shear resistance of the adhesive. Peel strength and shear strength also increases with increase in rate of testing, an observation which is associated to the viscoeslastic response of the adhesive. Differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR) study confirms the miscibility of tackifier and the ENR 25.

Microstructural Developments Leading to New Advanced High Strength Sheet Steels: A Historical Assessment of Critical Metallographic Observations

Energy Technology Data Exchange (ETDEWEB)

Matlock, David K [CSM/ASPPRC; Thomas, Larrin S [CSM/ASPPRC; Taylor, Mark D [CSM/ASPPRC; De Moor, Emmanuel [CSM/ASPPRC; Speer, John G [CSM/ASPPRC

2015-08-03

In the past 30+ years significant advancements have been made in the development of higher strength sheet steels with improved combinations of strength and ductility that have enabled important product improvements leading to safer, lighter weight, and more fuel efficient automobiles and in other applications. Properties of the primarily low carbon, low alloy steels are derived through careful control of time-temperature processing histories designed to produce multiphase ferritic based microstructures that include martensite and other constituents including retained austenite. The basis for these developments stems from the early work on dual-phase steels which was the subject of much interest. In response to industry needs, dual-phase steels have evolved as a unique class of advanced high strength sheet steels (AHSS) in which the thermal and mechanical processing histories have been specifically designed to produce constituent combinations for the purpose of simultaneously controlling strength and deformation behavior, i.e. stress-strain curve shapes. Improvements continue as enhanced dual-phase steels have recently been produced with finer microstructures, higher strengths, and better overall formability. Today, dual phase steels are the primary AHSS products used in vehicle manufacture, and several companies have indicated that the steels will remain as important design materials well into the future. In this presentation, fundamental results from the early work on dual-phase steels will be reviewed and assessed in light of recent steel developments. Specific contributions from industry/university cooperative research leading to product improvements will be highlighted. The historical perspective provided in the evolution of dual-phase steels represents a case-study that provides important framework and lessons to be incorporated in next generation AHSS products.

Effect of Body Mass Index on Postural Balance and Muscle Strength in Children Aged 8-10 years

Directory of Open Access Journals (Sweden)

Lucky Prasetiowati

2017-04-01

Full Text Available Background:Childhood overweight and obesity, which are considered as global epidemic, can be assessed using Body Mass Index (BMI. BMI difference can lead to anatomic changes due to an increased body load. This increase might also affect motor performance, including changes in postural balance and muscle strength. Aims and Objectives: to explain the influence of BMI on postural balance and lower limb muscle strength and to assess the correlation between those two variables in children aged 8-10 years. Material and methods:The sample consisted of 63 children aged 8-10 years, which were divided in 3 groups: BMI-normal, BMI-overweight, and BMI-obese. The postural balance was assessed using single leg balance test on MatScan and the Center Of Pressure (COP area was recorded. Isometric muscle strength of hip extensor and knee extensor were measured using a hand-held dynamometer. Results: Obese children had significantly largerCOP area than overweight (p = 0.004 and normal weight children (p = 0.000.There were no significant differences in hip extensor muscle strength between obese children with overweight and normal weight children (p=0.527. The absolute knee extensor muscle strength in obese group was significantly higher than the overweight and normal group (p = 0.003. However the relative muscle strength of lower limb for obese children was significantly lower than for normal weight. There was no significant correlation between absolute hip extensor and knee extensor muscles strength with COP area. Conclusion: Obese children have decreased postural balance and increased absolute knee extensormuscle strength significantly when compared to overweight and normal children. There is no significant correlation between postural balance and muscle strength.

Light-weight alloys for aerospace applications II; Proceedings of the 2nd Symposium, New Orleans, LA, Feb. 17-21, 1991

International Nuclear Information System (INIS)

Lee, E.W.; Kim, N.J.

1991-01-01

The present symposium on applications of light-weight alloys for aerospace discusses Al-Li alloys, aluminum alloys, advanced composites, and light alloys. Attention is given to Al-Li alloy development for parts made from thick plates, the structure and properties of P/M-aluminum alloys, X-ray rocking curve analysis of aging and deformation characteristics in Al-Li alloys, and the transformation characteristics of the 2090 Al-Li alloy. Topics considered include microstructural development in a rapidly solidified Al-Fe-V-Si alloy, the structure and mechanical properties of rapidly solidified Al-Cr-Hf alloys, the deformation mechanisms in superplastic Al-Mg alloys by microtexture technique, and the design of powder metallurgy aluminum alloys. Also discussed are the mechanical properties of monolithic and particular composites of L1(2) forms of Al3Ti, in situ polymer fiber-reinforced hybrid materials, thermal cycling of Ti-1421/SiC metal matrix composites, and the fracture behavior of a Ti3-Al-Nb alloy

Robustness of weighted networks

Science.gov (United States)

Bellingeri, Michele; Cassi, Davide

2018-01-01

Complex network response to node loss is a central question in different fields of network science because node failure can cause the fragmentation of the network, thus compromising the system functioning. Previous studies considered binary networks where the intensity (weight) of the links is not accounted for, i.e. a link is either present or absent. However, in real-world networks the weights of connections, and thus their importance for network functioning, can be widely different. Here, we analyzed the response of real-world and model networks to node loss accounting for link intensity and the weighted structure of the network. We used both classic binary node properties and network functioning measure, introduced a weighted rank for node importance (node strength), and used a measure for network functioning that accounts for the weight of the links (weighted efficiency). We find that: (i) the efficiency of the attack strategies changed using binary or weighted network functioning measures, both for real-world or model networks; (ii) in some cases, removing nodes according to weighted rank produced the highest damage when functioning was measured by the weighted efficiency; (iii) adopting weighted measure for the network damage changed the efficacy of the attack strategy with respect the binary analyses. Our results show that if the weighted structure of complex networks is not taken into account, this may produce misleading models to forecast the system response to node failure, i.e. consider binary links may not unveil the real damage induced in the system. Last, once weighted measures are introduced, in order to discover the best attack strategy, it is important to analyze the network response to node loss using nodes rank accounting the intensity of the links to the node.

Experienced Poor Lighting Contributes to the Seasonal Fluctuations in Weight and Appetite That Relate to the Metabolic Syndrome

Directory of Open Access Journals (Sweden)

Sharon Grimaldi

2009-01-01

Full Text Available We tested which environmental, social, lifestyle, and health related factors of the individual contribute to the seasonal variations in mood and behavior and whether these influence the risks of the metabolic syndrome and major depressive disorder, both conditions having a high prevalence in industrialized populations. 5480 individuals, representative of the general population aged 30 and over in Finland, were assessed for metabolic syndrome using the ATP-III criteria, gave a self-report of seasonal variations in mood and behavior, and were interviewed for mood, anxiety, and alcohol use disorders using the DSM-IV criteria. The seasonal variations in mood and behavior have a metabolic factor composed of weight and appetite, and greater loadings on this factor increased the risk of metabolic syndrome (odds ratio of 1.18, 95% confidence interval of 1.10 to 1.26. Self-reports of lighting experienced as poor at home contributed to scores on the metabolic factor (t=4.20,P<.0001. Lighting conditions and their dynamics may serve as a measure for intervention in order to influence the seasonal metabolic signals and in the end to prevent the metabolic syndrome.

Experienced Poor Lighting Contributes to the Seasonal Fluctuations in Weight and Appetite That Relate to the Metabolic Syndrome

International Nuclear Information System (INIS)

Grimaldi, S.; Englund, A.; Partonen, T.

2010-01-01

We tested which environmental, social, lifestyle, and health related factors of the individual contribute to the seasonal variations in mood and behavior and whether these influence the risks of the metabolic syndrome and major depressive disorder, both conditions having a high prevalence in industrialized populations. 5480 individuals, representative of the general population aged 30 and over in Finland, were assessed for metabolic syndrome using the ATP-III criteria, gave a self-report of seasonal variations in mood and behavior, and were interviewed for mood, anxiety, and alcohol use disorders using the DSM-IV criteria. The seasonal variations in mood and behavior have a metabolic factor composed of weight and appetite, and greater loadings on this factor increased the risk of metabolic syndrome (odds ratio of 1.18, 95% confidence interval of 1.10 to 1.26). Self-reports of lighting experienced as poor at home contributed to scores on the metabolic factor (t=4.20,P<.0001). Lighting conditions and their dynamics may serve as a measure for intervention in order to influence the seasonal metabolic signals and in the end to prevent the metabolic syndrome.

Effects of different strength training frequencies on maximum strength, body composition and functional capacity in healthy older individuals.

Science.gov (United States)

Turpela, Mari; Häkkinen, Keijo; Haff, Guy Gregory; Walker, Simon

2017-11-01

There is controversy in the literature regarding the dose-response relationship of strength training in healthy older participants. The present study determined training frequency effects on maximum strength, muscle mass and functional capacity over 6months following an initial 3-month preparatory strength training period. One-hundred and six 64-75year old volunteers were randomly assigned to one of four groups; performing strength training one (EX1), two (EX2), or three (EX3) times per week and a non-training control (CON) group. Whole-body strength training was performed using 2-5 sets and 4-12 repetitions per exercise and 7-9 exercises per session. Before and after the intervention, maximum dynamic leg press (1-RM) and isometric knee extensor and plantarflexor strength, body composition and quadriceps cross-sectional area, as well as functional capacity (maximum 7.5m forward and backward walking speed, timed-up-and-go test, loaded 10-stair climb test) were measured. All experimental groups increased leg press 1-RM more than CON (EX1: 3±8%, EX2: 6±6%, EX3: 10±8%, CON: -3±6%, Ptraining frequency would induce greater benefit to maximum walking speed (i.e. functional capacity) despite a clear dose-response in dynamic 1-RM strength, at least when predominantly using machine weight-training. It appears that beneficial functional capacity improvements can be achieved through low frequency training (i.e. 1-2 times per week) in previously untrained healthy older participants. Copyright © 2017 Elsevier Inc. All rights reserved.

Weighted straight skeletons in the plane.

Science.gov (United States)

Biedl, Therese; Held, Martin; Huber, Stefan; Kaaser, Dominik; Palfrader, Peter

2015-02-01

We investigate weighted straight skeletons from a geometric, graph-theoretical, and combinatorial point of view. We start with a thorough definition and shed light on some ambiguity issues in the procedural definition. We investigate the geometry, combinatorics, and topology of faces and the roof model, and we discuss in which cases a weighted straight skeleton is connected. Finally, we show that the weighted straight skeleton of even a simple polygon may be non-planar and may contain cycles, and we discuss under which restrictions on the weights and/or the input polygon the weighted straight skeleton still behaves similar to its unweighted counterpart. In particular, we obtain a non-procedural description and a linear-time construction algorithm for the straight skeleton of strictly convex polygons with arbitrary weights.

Relationship between lung function and grip strength in older hospitalized patients: a pilot study

Directory of Open Access Journals (Sweden)

Holmes SJ

2017-04-01

Full Text Available Sarah J Holmes,1 Stephen C Allen,2,3 Helen C Roberts4,5 1Medicine and Elderly Care, Hampshire Hospitals NHS Foundation Trust, Winchester, 2Medicine and Geriatrics, The Royal Bournemouth Hospital and Christchurch Hospitals NHS Foundation Trust, Bournemouth, 3Centre of Postgraduate Medical Research and Education, Bournemouth University, Poole, 4Academic Geriatric Medicine, University of Southampton, 5University Hospital Southampton NHS Foundation Trust, Southampton, UK Objective: Older people with reduced respiratory muscle strength may be misclassified as having COPD on the basis of spirometric results. We aimed to evaluate the relationship between lung function and grip strength in older hospitalized patients without known airways disease.Methods: Patients in acute medical wards were recruited who were aged ≥70 years; no history, symptoms, or signs of respiratory disease; Mini Mental State Examination ≥24; willing and able to consent to participate; and able to perform hand grip and forced spirometry. Data including lung function (forced expiratory volume in 1 second [FEV1], forced vital capacity [FVC], FEV1/FVC, peak expiratory flow rate [PEFR], and slow vital capacity [SVC], grip strength, age, weight, and height were recorded. Data were analyzed using descriptive statistics and linear regression unadjusted and adjusted (for age, height, and weight.Results: A total of 50 patients (20 men were recruited. Stronger grip strength in men was significantly associated with greater FEV1, but this was attenuated by adjustment for age, height, and weight. Significant positive associations were found in women between grip strength and both PEFR and SVC, both of which remained robust to adjustment.Conclusion: The association between grip strength and PEFR and SVC may reflect stronger patients generating higher intrathoracic pressure at the start of spirometry and pushing harder against thoracic cage recoil at end-expiration. Conversely, patients with

Impact strength of the uranium-6 weight percent niobium alloy between -1980 and +2000C

International Nuclear Information System (INIS)

Anderson, R.C.

1981-09-01

A study was conducted to determine if a ductile-to-brittle transition wxisted for the uranium-6 wt % niobium (U-6Nb) alloy. Standard V-notched Charpy bars were made from both solution-quenched and solution-quenched and aged U-6Nb alloy and were tested between -198 0 and +200 0 C. It was found that a sharp ductile-brittle transition does not exist for the alloy. A linear relationship existed between test temperature and impact strength, and the alloy retained a significant amount of impact strength even at very low temperatures. 9 figures

Mechanical strength of [HA/Bioplastic/Sericin] composite part printed by bioprinter

Energy Technology Data Exchange (ETDEWEB)

Tontowi, Alva Edy, E-mail: alvaedytontowi@ugm.ac.id; Setiawan, Agris [Department of Mechanical and Industrial Engineering Faculty of Engineering Universitas Gadjah Mada (Indonesia)

2016-06-17

The aim of this research was to determine the effect of hydroxyapatite (HA) content in printed biocomposite to its mechanical strength. The biocomposite paste was prepared by composing HA, bioplastic and sericin with various ratios of [HA/Bioplastic]: 40/60, 50/50, 60,40 and 70/30. Sericin of 0.3% weight was added to the biocomposite. Mechanical test was conducted to observe tensile (ASTM D 638 type 4) and flexural strength (ASTM D 790). Both type of specimens were fabricated using 3D Printer. Printing process parameter (infill speed, print speed and layer height) were set up as 60 mm/s, 10 mm/s, 0.35 mm, respectively. Results showed that biocomposite with [HA/Biplastic]. weight ratio of 60/40(w/w) has an optimum tensile (3.89 ± 1.26 MPa) and flexural strength (2.51 ± 0.45 MPa). Scanning electron microscope observation indicated that microstructure of specimen was influenced by the percentage of the hydroxyapatite. There was no agglomeration of HA particle within the composite.

Mechanical strength of [HA/Bioplastic/Sericin] composite part printed by bioprinter

International Nuclear Information System (INIS)

Tontowi, Alva Edy; Setiawan, Agris

2016-01-01

The aim of this research was to determine the effect of hydroxyapatite (HA) content in printed biocomposite to its mechanical strength. The biocomposite paste was prepared by composing HA, bioplastic and sericin with various ratios of [HA/Bioplastic]: 40/60, 50/50, 60,40 and 70/30. Sericin of 0.3% weight was added to the biocomposite. Mechanical test was conducted to observe tensile (ASTM D 638 type 4) and flexural strength (ASTM D 790). Both type of specimens were fabricated using 3D Printer. Printing process parameter (infill speed, print speed and layer height) were set up as 60 mm/s, 10 mm/s, 0.35 mm, respectively. Results showed that biocomposite with [HA/Biplastic]. weight ratio of 60/40(w/w) has an optimum tensile (3.89 ± 1.26 MPa) and flexural strength (2.51 ± 0.45 MPa). Scanning electron microscope observation indicated that microstructure of specimen was influenced by the percentage of the hydroxyapatite. There was no agglomeration of HA particle within the composite.

The Strength of Friendship Ties in Proximity Sensor Data

DEFF Research Database (Denmark)

Sekara, Vedran; Jørgensen, Sune Lehmann

2014-01-01

strength parameter to distinguish between observations, we demonstrate that weak links, compared to strong links, have a lower probability of being observed at later times, while such links—on average—also have lower link-weights and probability of sharing an online friendship. Further, the role of link...

The role of haptic versus visual volume cues in the size-weight illusion.

Science.gov (United States)

Ellis, R R; Lederman, S J

1993-03-01

Three experiments establish the size-weight illusion as a primarily haptic phenomenon, despite its having been more traditionally considered an example of vision influencing haptic processing. Experiment 1 documents, across a broad range of stimulus weights and volumes, the existence of a purely haptic size-weight illusion, equal in strength to the traditional illusion. Experiment 2 demonstrates that haptic volume cues are both sufficient and necessary for a full-strength illusion. In contrast, visual volume cues are merely sufficient, and produce a relatively weaker effect. Experiment 3 establishes that congenitally blind subjects experience an effect as powerful as that of blindfolded sighted observers, thus demonstrating that visual imagery is also unnecessary for a robust size-weight illusion. The results are discussed in terms of their implications for both sensory and cognitive theories of the size-weight illusion. Applications of this work to a human factors design and to sensor-based systems for robotic manipulation are also briefly considered.

Short communication: pre- and co-curing effect of adhesives on shear bond strengths of composite resins to primary enamel and dentine: an in vitro study.

Science.gov (United States)

Viswanathan, R; Shashibhushan, K K; Subba Reddy, V V

2011-12-01

To evaluate and compare shear bond strengths of composite resins to primary enamel and dentine when the adhesives are pre-cured (light cured before the application of the resin) or co-cured (adhesive and the resin light cured together). Buccal surfaces of 80 caries-free primary molars were wet ground to create bonding surfaces on enamel and dentine and specimens mounted on acrylic blocks. Two bonding agents (Prime and Bond NT® and Xeno III®) were applied to either enamel or dentine as per manufacturer's instructions. In 40 specimens, the bonding agent was light cured immediately after the application (pre-cured). The other 40 specimens were not light cured until the composite resin application (co-cured). Resin composite cylinders were made incrementally using acrylic moulds over the adhesives and light cured. Specimens were stored in deionised water for 24 hours at room temperature. Shear bond strength was measured using an Instron universal testing machine (in MPa) and was analysed with Student's unpaired t test. Light curing the adhesive separately produced significantly higher bond strengths to primary dentine than co-curing (padhesive separately did not produce significantly different bond strengths to primary enamel (p>0.05). Curing sequence had no significant effect on shear bond strength of adhesives on the primary enamel. Pre-curing adhesives before curing composite resins produced greater shear bond strength to primary dentine.

AND EXPLOSIVE STRENGTH OF YOUNG GYMNASTS

Directory of Open Access Journals (Sweden)

G. Dallas

2014-08-01

Full Text Available The purpose of this study was to examine the acute effect of a single bout of whole body vibration (WBV on flexibility and explosive strength of lower limbs in young artistic gymnasts. Thirty-two young competitive gymnasts volunteered to participate in this study, and were allocated to either the vibration group or traditional body weight training according to the vibration protocol. The vibration intervention consisted of a single bout of eccentric and concentric squatting movements on a vibration platform that was turned on (vibration group: VG n=15, whereas the traditional body weight (no vibration group performed the same training protocol with the WBV device turned off (NVG: n= 17. Flexibility (sit and reach test and explosive strength tests [squat jump (SJ, counter movement jump (CMJ, and single leg squat (right leg (RL and left leg (LL] were performed initially (pre-test, immediately after the intervention (post-test 1, and 15 minutes after the end of the intervention programme (post-test 15. Four 2x3 ANOVAs were used to examine the interaction between group (VG vs NVG and time (pre, post 1, and post 15 with respect to examined variables. The results revealed that a significant interaction between group and time was found with respect to SJ (p 0.05. Further, the percentage improvement of the VG was significantly greater in all examined variables compared to the NVG. This study concluded that WBV training improves flexibility and explosive strength of lower limbs in young trained artistic gymnasts and maintains the initial level of performance for at least 15 minutes after the WBV intervention programme.

Isokinetic Extension Strength Is Associated With Single-Leg Vertical Jump Height.

Science.gov (United States)

Fischer, Felix; Blank, Cornelia; Dünnwald, Tobias; Gföller, Peter; Herbst, Elmar; Hoser, Christian; Fink, Christian

2017-11-01

Isokinetic strength testing is an important tool in the evaluation of the physical capacities of athletes as well as for decision making regarding return to sports after anterior cruciate ligament (ACL) reconstruction in both athletes and the lay population. However, isokinetic testing is time consuming and requires special testing equipment. A single-jump test, regardless of leg dominance, may provide information regarding knee extension strength through the use of correlation analysis of jump height and peak torque of isokinetic muscle strength. Cross-sectional study; Level of evidence, 3. A total of 169 patients who underwent ACL reconstruction were included in this study. Isokinetic testing was performed on the injured and noninjured legs. Additionally, a single-leg countermovement jump was performed to assess jump height using a jump accelerometer sensor. Extension strength values were used to assess the association between isokinetic muscle strength and jump height. The sample consisted of 60 female (mean age, 20.8 ± 8.3 years; mean weight, 61.7 ± 6.5 kg; mean height, 167.7 ± 5.3 cm) and 109 male (mean age, 23.2 ± 7.7 years; mean weight, 74.6 ± 10.2 kg; mean height, 179.9 ± 6.9 cm) patients. Bivariate correlation analysis showed an association ( r = 0.56, P jump height and isokinetic extension strength on the noninvolved side as well as an association ( r = 0.52, P jump height (beta = 0.49, P jump height having the strongest impact (beta = 0.49, P jump height. The study population encompassed various backgrounds, skill levels, and activity profiles, which might have affected the outcome. Even after controlling for age and sex, isokinetic strength was still moderately associated with jump height. Therefore, the jump technique and type of sport should be considered in future research.

Effect of silica fume on compressive strength of oil-polluted concrete in different marine environments

Science.gov (United States)

Shahrabadi, Hamid; Sayareh, Sina; Sarkardeh, Hamed

2017-12-01

In the present research, effect of silica fume as an additive and oil polluted sands as aggregates on compressive strength of concrete were investigated experimentally. The amount of oil in the designed mixtures was assumed to be constant and equal to 2% of the sand weight. Silica fume accounting for 10%, 15% and 20% of the weight is added to the designed mixture. After preparation and curing, concrete specimens were placed into the three different conditions: fresh, brackish and saltwater environments (submerged in fresh water, alternation of exposed in air & submerged in sea water and submerged in sea water). The result of compressive strength tests shows that the compressive strength of the specimens consisting of silica fume increases significantly in comparison with the control specimens in all three environments. The compressive strength of the concrete with 15% silica fume content was about 30% to 50% higher than that of control specimens in all tested environments under the condition of using polluted aggregates in the designed mixture.

Influence of different conditioning methods on the shear bond strength of novel light-curing nano-ionomer restorative to enamel and dentin.

Science.gov (United States)

Korkmaz, Yonca; Ozel, Emre; Attar, Nuray; Ozge Bicer, Ceren

2010-11-01

The purpose of this study was to investigate shear bond strength (SBS) between a light-curing nano-ionomer restorative and enamel or dentin after acid etching, after erbium:yttrium-aluminum-garnet (Er:YAG) laser etching, or after combined treatment. Forty third molars were selected, the crowns were sectioned, and 80 tooth slabs were obtained. The specimens were assigned to two groups, which were divided into four subgroups(n = 10). Group 1 [enamel (e)], treated with 37% phosphoric acid (A) + Ketac nano-primer (K); group 2 [dentin (d)], (A) + (K); group 3(e), Er:YAG laser etching (L) + (A) + (K); group 4(d), (L) + (A) + (K); group 5(e), (L) + (K); group 6(d), (L) + (K); group 7(e), (K); group 8(d), (K). The SBS of the specimens was measured with a universal test machine (1 mm/min). Data were analyzed by independent samples t-test, one-way analysis of variance (ANOVA) and a post-hoc Duncan test (p 0.05). Group 7 exhibited higher SBS values than those of groups 3 and 5 (p 0.05). No difference was observed between groups 2 and 4 (p > 0.05). However, group 2 presented higher SBSs than did group 6 (p adhesion of the light-curing nano-ionomer restorative to both enamel and dentin.

[Body, strength, and labor: reflexions in the light of gender relations].

Science.gov (United States)

Costa, L H

2000-01-01

The present paper intends to contribute on a reflection and discussion of some issues related to female's body and the strength present in laborwork, understood as the moment in which through the support of another person, a woman "gives birth". It also discusses the perspective of male dominance having as reference the symbolic violence from Bordieu, proposing that the humanizing of labor demands a thorough discussion on gender dominance.

Influence of Body Weight on Bone Mass, Architecture, and Turnover

Science.gov (United States)

Iwaniec, Urszula T.; Turner, Russell T.

2016-01-01

Weight-dependent loading of the skeleton plays an important role in establishing and maintaining bone mass and strength. This review focuses on mechanical signaling induced by body weight as an essential mechanism for maintaining bone health. In addition, the skeletal effects of deviation from normal weight are discussed. The magnitude of mechanical strain experienced by bone during normal activities is remarkably similar among vertebrates, regardless of size, supporting the existence of a conserved regulatory mechanism, or mechanostat, that senses mechanical strain. The mechanostat functions as an adaptive mechanism to optimize bone mass and architecture based on prevailing mechanical strain. Changes in weight, due to altered mass, weightlessness (spaceflight), and hypergravity (modeled by centrifugation), induce an adaptive skeletal response. However, the precise mechanisms governing the skeletal response are incompletely understood. Furthermore, establishing whether the adaptive response maintains the mechanical competence of the skeleton has proven difficult, necessitating development of surrogate measures of bone quality. The mechanostat is influenced by regulatory inputs to facilitate non-mechanical functions of the skeleton, such as mineral homeostasis, as well as hormones and energy/nutrient availability that support bone metabolism. While the skeleton is very capable of adapting to changes in weight, the mechanostat has limits. At the limits, extreme deviations from normal weight and body composition are associated with impaired optimization of bone strength to prevailing body size. PMID:27352896

Implantable electronics: emerging design issues and an ultra light-weight security solution.

Science.gov (United States)

Narasimhan, Seetharam; Wang, Xinmu; Bhunia, Swarup

2010-01-01

Implantable systems that monitor biological signals require increasingly complex digital signal processing (DSP) electronics for real-time in-situ analysis and compression of the recorded signals. While it is well-known that such signal processing hardware needs to be implemented under tight area and power constraints, new design requirements emerge with their increasing complexity. Use of nanoscale technology shows tremendous benefits in implementing these advanced circuits due to dramatic improvement in integration density and power dissipation per operation. However, it also brings in new challenges such as reliability and large idle power (due to higher leakage current). Besides, programmability of the device as well as security of the recorded information are rapidly becoming major design considerations of such systems. In this paper, we analyze the emerging issues associated with the design of the DSP unit in an implantable system. Next, we propose a novel ultra light-weight solution to address the information security issue. Unlike the conventional information security approaches like data encryption, which come at large area and power overhead and hence are not amenable for resource-constrained implantable systems, we propose a multilevel key-based scrambling algorithm, which exploits the nature of the biological signal to effectively obfuscate it. Analysis of the proposed algorithm in the context of neural signal processing and its hardware implementation shows that we can achieve high level of security with ∼ 13X lower power and ∼ 5X lower area overhead than conventional cryptographic solutions.

The effect of cobalt and molybdenum on the creep strength of low C-18Cr-10Ni steel

International Nuclear Information System (INIS)

Tomono, Yutaka; Ueda, Jitsuhiko

1982-01-01

The improvement of creep strength through the addition of cobalt and molybdenum to low C-18Cr-10Ni steel was studied at a temperature range of between 700 and 800 0 C. Changes in mechanical and physical properties such as lattice parameter and stacking fault energy, related to the additional elements were investigated to estimate the strengthening effect. Dislocation structures corresponding to the various creep stages were observed through a transmission electron microscope to distinguish the solution hardening effect of the added elements from the precipitation hardening effects of carbide. The results obtained are summarized as follows: (1) Addition of cobalt of up to 20% by weight improved the creep strength of austenitic steel. Addition of molybdenum of up to 5% by weight remarkably improved the creep strength of austenitic steel having a cobalt content of 20% by weight. (2) The trend for creep strength to improve with the addition of these elements was closely coincident with increases in lattice parameter and did not necessarily coincide with changes in the stacking fault energy. (author)

Anelasticity and strength in zirconia ceramics

International Nuclear Information System (INIS)

Matsuzawa, M.; Horibe, S.; Sakai, J.

2005-01-01

Non-elastic strain behavior was investigated for several different zirconia ceramics and a possible mechanism for anelasticity was discussed. Anelastic strain was detected in zirconia ceramics irrespective of the crystallographic phase and its productivity depended on the particular kind of dopant additive. It was found that the anelastic properties could be significantly influenced by the level of oxygen vacancy in the matrix, and that the anelastic strain might be produced by a light shift of ionic species. In order to investigate the effect of anelasticity on mechanical properties on zirconia ceramics, the tensile strength was investigated for a wide range of strain rates. The obviously unique strain rate dependence was observed only in the materials having anelastic properties. It was assumed that anelasticity could be efficient at improving the tensile strength. (orig.)

Impact of dispersed coupling strength on the free running periods of circadian rhythms

Science.gov (United States)

Gu, Changgui; Rohling, Jos H. T.; Liang, Xiaoming; Yang, Huijie

2016-03-01

The dominant endogenous clock, named the suprachiasmatic nucleus (SCN), regulates circadian rhythms of behavioral and physiological activity in mammals. One of the main characteristics of the SCN is that the animal maintains a circadian rhythm with a period close to 24 h in the absence of a daily light-dark cycle (called the free running period). The free running period varies among species due to heterogeneity of the SCN network. Previous studies have shown that the heterogeneity in cellular coupling as well as in intrinsic neuronal periods shortens the free running period. Furthermore, as derived from experiments, one neuron's coupling strength is negatively associated with its period. It is unknown what the effects of this association between coupling strength and period are on the free running period and how the heterogeneity in coupling strength influences this free running period. In the present study we found that in the presence of a negative relationship between one neuron's coupling strength and its period, surprisingly, the dispersion of coupling strengths increases the free running period. Our present finding may shed new light on the understanding of the heterogeneous SCN network and provides an alternative explanation for the diversity of free running periods between species.

Argument Strength and the Persuasiveness of Stories

Science.gov (United States)

Schreiner, Constanze; Appel, Markus; Isberner, Maj-Britt; Richter, Tobias

2017-01-01

ABSTRACT Stories are a powerful means to change people’s attitudes and beliefs. The aim of the current work was to shed light on the role of argument strength (argument quality) in narrative persuasion. The present study examined the influence of strong versus weak arguments on attitudes in a low or high narrative context. Moreover, baseline attitudes, interindividual differences in working memory capacity, and recipients’ transportation were examined. Stories with strong arguments were more persuasive than stories with weak arguments. This main effect was qualified by a two-way interaction with baseline attitude, revealing that argument strength had a greater impact on individuals who initially were particularly doubtful toward the story claim. Furthermore, we identified a three-way interaction showing that argument strength mattered most for recipients who were deeply transported into the story world in stories that followed a typical narrative structure. These findings provide an important specification of narrative persuasion theory. PMID:29805322

Epidemic spreading on weighted complex networks

International Nuclear Information System (INIS)

Sun, Ye; Liu, Chuang; Zhang, Chu-Xu; Zhang, Zi-Ke

2014-01-01

Nowadays, the emergence of online services provides various multi-relation information to support the comprehensive understanding of the epidemic spreading process. In this Letter, we consider the edge weights to represent such multi-role relations. In addition, we perform detailed analysis of two representative metrics, outbreak threshold and epidemic prevalence, on SIS and SIR models. Both theoretical and simulation results find good agreements with each other. Furthermore, experiments show that, on fully mixed networks, the weight distribution on edges would not affect the epidemic results once the average weight of whole network is fixed. This work may shed some light on the in-depth understanding of epidemic spreading on multi-relation and weighted networks.

Epidemic spreading on weighted complex networks

Energy Technology Data Exchange (ETDEWEB)

Sun, Ye [Institute of Information Economy, Hangzhou Normal University, Hangzhou 311121 (China); Alibaba Research Center of Complexity Science, Hangzhou Normal University, Hangzhou 311121 (China); Liu, Chuang, E-mail: liuchuang@hznu.edu.cn [Institute of Information Economy, Hangzhou Normal University, Hangzhou 311121 (China); Alibaba Research Center of Complexity Science, Hangzhou Normal University, Hangzhou 311121 (China); Zhang, Chu-Xu [Institute of Information Economy, Hangzhou Normal University, Hangzhou 311121 (China); Alibaba Research Center of Complexity Science, Hangzhou Normal University, Hangzhou 311121 (China); Zhang, Zi-Ke, E-mail: zhangzike@gmail.com [Institute of Information Economy, Hangzhou Normal University, Hangzhou 311121 (China); Alibaba Research Center of Complexity Science, Hangzhou Normal University, Hangzhou 311121 (China)

2014-01-31

Nowadays, the emergence of online services provides various multi-relation information to support the comprehensive understanding of the epidemic spreading process. In this Letter, we consider the edge weights to represent such multi-role relations. In addition, we perform detailed analysis of two representative metrics, outbreak threshold and epidemic prevalence, on SIS and SIR models. Both theoretical and simulation results find good agreements with each other. Furthermore, experiments show that, on fully mixed networks, the weight distribution on edges would not affect the epidemic results once the average weight of whole network is fixed. This work may shed some light on the in-depth understanding of epidemic spreading on multi-relation and weighted networks.

The Exposure Effects of Online Model Pictures and Weight-Related Persuasive Messages on Women's Weight-Loss Planned Behaviors.

Science.gov (United States)

Pan, Wenjing; Peña, Jorge

2017-10-01

This study examined how exposure to pictures of women with different body sizes (thin, obese), physical attractiveness levels (attractive, unattractive), along with exposure to weight-related messages (pro-anorexia, anti-anorexia) embedded in a fashion website affected female participants' planned behavior toward weight loss. Participants exposed to attractive model pictures showed higher intentions, attitudes, and subjective norms to lose weight compared with unattractive models. Additionally, participants exposed to thin and attractive model pictures indicated the highest attitudes and self-efficacy to lose weight, whereas those exposed to thin and unattractive model pictures indicated the lowest. Furthermore, weight-related messages moderated the effect of model appearance (body size and attractiveness) on controllability of weight-loss activities. However, website pictures' body size differences had no main effects on planned behavior toward weight loss. These effects are discussed in the light of social comparison mechanisms.

Back muscle strength, lifting, and stooped working postures.

Science.gov (United States)

Poulsen, E; Jørgensen, K

1971-09-01

When lifting loads and working in a forward stooped position, the muscles of the back rather than the ligaments and bony structures of the spine should overcome the gravitational forces. Formulae, based on measurements of back muscle strength, for prediction of maximal loads to be lifted, and for the ability to sustain work in a stooped position, have been worked out and tested in practical situations. From tests with 50 male and female subjects the simplest prediction formulae for maximum loads were: max. load = 1.10 x isometric back muscle strength for men; and max. load = 0.95 x isometric back muscle strength - 8 kg for women. Some standard values for maximum lifts and permissible single and repeated lifts have been calculated for men and women separately and are given in Table 1. From tests with 65 rehabilitees it was found that the maximum isometric strength of the back muscles measured at shoulder height should exceed 2/3 of the body weight, if fatigue and/or pain in the back muscles is to be avoided during work in a standing stooped position.

Muscle performance following an acute bout of plyometric training combined with low or high intensity weight exercise.

Science.gov (United States)

Beneka, Anastasia G; Malliou, Paraskevi K; Missailidou, Victoria; Chatzinikolaou, Athanasios; Fatouros, Ioannis; Gourgoulis, Vassilios; Georgiadis, Elias

2013-01-01

To determine the time course of performance responses after an acute bout of plyometric exercise combined with high and low intensity weight training, a 3-group (including a control group), repeated-measures design was employed. Changes in performance were monitored through jumping ability by measuring countermovement and squat jumping, and strength performance assessment through isometric and isokinetic testing of knee extensors (at two different velocities). Participants in both experimental groups performed a plyometric protocol consisting of 50 jumps over 50 cm hurdles and 50 drop jumps from a 50 cm plyometric box. Additionally, each group performed two basic weight exercises consisting of leg presses and leg extensions at 90-95% of maximum muscle strength for the high intensity group and 60% of maximum muscle strength for the low intensity group. The results of the study suggest that an acute bout of intense plyometric exercise combined with weight exercise induces time-dependent changes in performance, which are also dependent on the nature of exercise protocol and testing procedures. In conclusion, acute plyometric exercise with weight exercise may induce a substantial decline in jumping performance for as long as 72 hours but not in other forms of muscle strength.

Weightlifting, weight training and injuries.

Science.gov (United States)

Basford, J R

1985-08-01

Although millions of men and women in the United States are regularly involved in some form of weightlifting, the average physician knows, and frequently cares, little about the sports involved. As a result, his or her knowledge of the medical and physiological issues involved is limited This article attempts to address this lack by beginning with a brief introductory section outlining some of the similarities differences between the major weight lifting approaches (power lifting, olympic lifting, weight training and body building). Next it reviews major issues and controversies such as age restrictions for lifters, physiological effects, drug use, potential strength gains and hypertrophy. Finally, it discusses some of the more frequent and unique injuries that can occur in lifters.

M2Lite: An Open-source, Light-weight, Pluggable and Fast Proteome Discoverer MSF to mzIdentML Tool.

Science.gov (United States)

Aiyetan, Paul; Zhang, Bai; Chen, Lily; Zhang, Zhen; Zhang, Hui

2014-04-28

Proteome Discoverer is one of many tools used for protein database search and peptide to spectrum assignment in mass spectrometry-based proteomics. However, the inadequacy of conversion tools makes it challenging to compare and integrate its results to those of other analytical tools. Here we present M2Lite, an open-source, light-weight, easily pluggable and fast conversion tool. M2Lite converts proteome discoverer derived MSF files to the proteomics community defined standard - the mzIdentML file format. M2Lite's source code is available as open-source at https://bitbucket.org/paiyetan/m2lite/src and its compiled binaries and documentation can be freely downloaded at https://bitbucket.org/paiyetan/m2lite/downloads.

Strength resistance test of superior members for elderly people: comparison between dumbbells with different weights

Directory of Open Access Journals (Sweden)

Marize Amorim Lopes

2008-06-01

Full Text Available The aim of the study was to compare the performance of elderly people in the strength resistance test of superior members (SRTSM with dumbbells of different weights (1,8 kg and 2 kg for women and 3,6 kg and 4 kg for men. The sample consisted of 407 elderly (349 feminine and 58 masculine, with age of 60 to 88 years, practitioners of physical exercise for at least six months. The used instrument was the SRTSM of the battery of tests American Alliance for Health, Physical Education, Recreation and Dance (AAHPERD. Two executions of the test were carried through with dumbbells of different weights, SRTSM (1,8 kg and 3,6 kg and “adjusted” SRTSM (2 kg and 4 kg. For the analysis of the data, it was proceeded descriptive analysis, test t of Student for independent samples, paired t test for dependent samples and ANOVA with post-hoc of Tukey, adopting itself the 5% level significance. The results demonstrated that the use of dumbbells with 4 weights of 2 and kg, seem not to affect the performance of the elderly ones, mainly of the masculine sex. For the feminine sex significant difference in the averages of the second comparison carried through for the sort was detected. However, this difference can have been resulting from external factors to the test, since, the greater average obtained was for “the adjusted” SRTSM. Nevertheless, one tries to facilitate even more the evaluation of the functional capacity of the elderly population, being recommended for SRTSM the use of dumbbells with weight of 2 kg for women and 4kg for men that they are of low cost, easy acquisition and access in the Brazilian market. ResumoO objetivo do estudo foi comparar o desempenho de idosos no teste de resistência de força de membros superiores (RESISFOR com halteres de diferentes pesos (1,8 kg e 2 kg para mulheres e 3,6 kg e 4 kg para homens. A amostra foi constituída por 407 idosos (349 feminino e 58 masculino, com idade de 60 a 88 anos, praticantes de exercício f

Axial Compressive Strength of Foamcrete with Different Profiles and Dimensions

Directory of Open Access Journals (Sweden)

Othuman Mydin M.A.

2014-01-01

Full Text Available Lightweight foamcrete is a versatile material; primarily consist of a cement based mortar mixed with at least 20% volume of air. High flow ability, lower self-weight, minimal requirement of aggregate, controlled low strength and good thermal insulation properties are a few characteristics of foamcrete. Its dry densities, typically, is below 1600kg/m3 with compressive strengths maximum of 15MPa. The ASTM standard provision specifies a correction factor for concrete strengths of between 14 and 42MPa to compensate for the reduced strength when the aspect height-to-diameter ratio of specimen is less than 2.0, while the CEB-FIP provision specifically mentions the ratio of 150 x 300mm cylinder strength to 150 mm cube strength. However, both provisions requirements do not specifically clarify the applicability and/or modification of the correction factors for the compressive strength of foamcrete. This proposed laboratory work is intended to study the effect of different dimensions and profiles on the axial compressive strength of concrete. Specimens of various dimensions and profiles are cast with square and circular cross-sections i.e., cubes, prisms and cylinders, and to investigate their behavior in compression strength at 7 and 28 days. Hypothetically, compressive strength will decrease with the increase of concrete specimen dimension and concrete specimen with cube profile would yield comparable compressive strength to cylinder (100 x 100 x 100mm cube to 100dia x 200mm cylinder.

Community Weight Loss to Combat Obesity and Disability in At-Risk Older Adults.

Science.gov (United States)

Rejeski, W Jack; Ambrosius, Walter T; Burdette, Jonathan H; Walkup, Michael P; Marsh, Anthony P

2017-10-12

Among older, overweight, and obese adults with either cardiovascular disease or the metabolic syndrome, reduced mobility and loss of leg strength are important risk factors for morbidity, disability, and mortality. It is unclear whether community-based approaches to weight loss may be an effective solution to this public health challenge. An 18-month three-site, randomized controlled trial conducted by YMCA staff, with blinded assessors, enrolled 249 older, overweight, and obese adults with either cardiovascular disease or metabolic syndrome with randomization to three interventions: weight loss alone (WL), weight loss + aerobic training (WL + AT), and weight loss + resistance training (WT + RT). The dual primary outcomes were 400-m walk time in seconds and knee extensor strength in Newton meters. All groups lost weight from baseline: average baseline adjusted change of -6.1% (95% confidence interval [CI]: -7.5 to -4.7) for WL only, -8.6% (95% CI: -10.0 to -7.2) for WL + AT, and -9.7% (95% CI: -11.1 to -8.4) for WL + RT. Combined, the two physical activity + WL training groups had greater improvement in walk time than WL alone (mean difference 16.9 seconds [95% CI: 9.7 to 24.0], p < .0001). Baseline adjusted change in knee extensor strength was no greater with WL + RT than WL + AT (mean difference -3.6 Nm [95% CI: -7.5 to 0.3], p = .07). At risk, older, overweight and obese adults can achieve clinically significant reductions in body weight with community-based weight loss programs. The change in percent weight loss and improvements in mobility are significantly enhanced when either RT or AT is combined with dietary WL. © The Author 2017. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Effects of Vertex Activity and Self-organized Criticality Behavior on a Weighted Evolving Network

International Nuclear Information System (INIS)

Zhang Guiqing; Yang Qiuying; Chen Tianlun

2008-01-01

Effects of vertex activity have been analyzed on a weighted evolving network. The network is characterized by the probability distribution of vertex strength, each edge weight and evolution of the strength of vertices with different vertex activities. The model exhibits self-organized criticality behavior. The probability distribution of avalanche size for different network sizes is also shown. In addition, there is a power law relation between the size and the duration of an avalanche and the average of avalanche size has been studied for different vertex activities

Strong impact of ionic strength on the kinetics of fibrilar aggregation of bovine beta-lactoglobulin

NARCIS (Netherlands)

Arnaudov, L.N.; Vries, de R.J.

2006-01-01

We investigate the effect of ionic strength on the kinetics of heat-induced fibrilar aggregation of bovine -lactoglobulin at pH 2.0. Using in situ light scattering we find an apparent critical protein concentration below which there is no significant fibril formation for all ionic strengths studied.

Visualizing weighted networks: a performance comparison of adjacency matrices versus node-link diagrams

Science.gov (United States)

McIntire, John P.; Osesina, O. Isaac; Bartley, Cecilia; Tudoreanu, M. Eduard; Havig, Paul R.; Geiselman, Eric E.

2012-06-01

Ensuring the proper and effective ways to visualize network data is important for many areas of academia, applied sciences, the military, and the public. Fields such as social network analysis, genetics, biochemistry, intelligence, cybersecurity, neural network modeling, transit systems, communications, etc. often deal with large, complex network datasets that can be difficult to interact with, study, and use. There have been surprisingly few human factors performance studies on the relative effectiveness of different graph drawings or network diagram techniques to convey information to a viewer. This is particularly true for weighted networks which include the strength of connections between nodes, not just information about which nodes are linked to other nodes. We describe a human factors study in which participants performed four separate network analysis tasks (finding a direct link between given nodes, finding an interconnected node between given nodes, estimating link strengths, and estimating the most densely interconnected nodes) on two different network visualizations: an adjacency matrix with a heat-map versus a node-link diagram. The results should help shed light on effective methods of visualizing network data for some representative analysis tasks, with the ultimate goal of improving usability and performance for viewers of network data displays.

Morning and Evening Blue-Enriched Light Exposure Alters Metabolic Function in Normal Weight Adults.

Directory of Open Access Journals (Sweden)

Ivy N Cheung

Full Text Available Increasing evidence points to associations between light-dark exposure patterns, feeding behavior, and metabolism. This study aimed to determine the acute effects of 3 hours of morning versus evening blue-enriched light exposure compared to dim light on hunger, metabolic function, and physiological arousal. Nineteen healthy adults completed this 4-day inpatient protocol under dim light conditions (<20lux. Participants were randomized to 3 hours of blue-enriched light exposure on Day 3 starting either 0.5 hours after wake (n = 9; morning group or 10.5 hours after wake (n = 10; evening group. All participants remained in dim light on Day 2 to serve as their baseline. Subjective hunger and sleepiness scales were collected hourly. Blood was sampled at 30-minute intervals for 4 hours in association with the light exposure period for glucose, insulin, cortisol, leptin, and ghrelin. Homeostatic model assessment of insulin resistance (HOMA-IR and area under the curve (AUC for insulin, glucose, HOMA-IR and cortisol were calculated. Comparisons relative to baseline were done using t-tests and repeated measures ANOVAs. In both the morning and evening groups, insulin total area, HOMA-IR, and HOMA-IR AUC were increased and subjective sleepiness was reduced with blue-enriched light compared to dim light. The evening group, but not the morning group, had significantly higher glucose peak value during blue-enriched light exposure compared to dim light. There were no other significant differences between the morning or the evening groups in response to blue-enriched light exposure. Blue-enriched light exposure acutely alters glucose metabolism and sleepiness, however the mechanisms behind this relationship and its impacts on hunger and appetite regulation remain unclear. These results provide further support for a role of environmental light exposure in the regulation of metabolism.

Effect of a New Salivary Contaminant Removal Method on Bond Strength

Science.gov (United States)

2014-08-31

was to evaluate the effect of various salivary- contaminant removal methods on the shear bond strength of resin cement to hydrofluoric-acid (HF) etched...mold (Ultradent) to a height of 3mm and light cured . Specimens were stored for 24 hours in 37°C distilled water and then tested in shear in a... contamination which may compromise the bond strength of the resin cement to the ceramic (Aboush, 1998; van Schalkwyk et al., 2003). Saliva affects bond

Strength and power of knee extensor muscles

Directory of Open Access Journals (Sweden)

Knežević Olivera

2011-01-01

Full Text Available In the studies of human neuromuscular function, the function of leg muscles has been most often measured, particularly the function of the knee extensors. Therefore, this review will be focused on knee extensors, methods for assessment of its function, the interdependence of strength and power, relations that describe these two abilities and the influence of various factors on their production (resistance training, stretching, movement tasks, age, etc.. Given that it consists of four separate muscles, the variability of their anatomical characteristics affects their participation in strength and power production, depending on the type of movement and motion that is performed. Since KE is active in a variety of activities it must be able to generate great strength in a large and diverse range of muscle lengths and high shortening velocities, in respect to different patterns of strength production, and thus different generation capacities within the muscle (Blazevich et al., 2006. It has been speculated that KE exerts its Pmax at workloads close to subject's own body weight or lower (Rahmani et al., 2001, which is very close to the maximum dynamic output hypothesis (MDI of Jaric and Markovic (2009. Changes under the influence of resistance training or biological age are variously manifested in muscle's morphological, physiological and neural characteristics, and thus in strength and power. Understanding the issues related to strength and power as abilities of great importance for daily activities, is also important for sports and rehabilitation. Performances improvement in sports in which leg muscles strength and power are crucial, as well as recovery after the injuries, are largely dependent on the research results regarding KE function. Also, the appropriate strength balance between knee flexors and extensors is important for the knee joint stability, so that the presence of imbalance between these two muscle groups might be a risk factor for

Epidemic spreading on contact networks with adaptive weights.

Science.gov (United States)

Zhu, Guanghu; Chen, Guanrong; Xu, Xin-Jian; Fu, Xinchu

2013-01-21

The heterogeneous patterns of interactions within a population are often described by contact networks, but the variety and adaptivity of contact strengths are usually ignored. This paper proposes a modified epidemic SIS model with a birth-death process and nonlinear infectivity on an adaptive and weighted contact network. The links' weights, named as 'adaptive weights', which indicate the intimacy or familiarity between two connected individuals, will reduce as the disease develops. Through mathematical and numerical analyses, conditions are established for population extermination, disease extinction and infection persistence. Particularly, it is found that the fixed weights setting can trigger the epidemic incidence, and that the adaptivity of weights cannot change the epidemic threshold but it can accelerate the disease decay and lower the endemic level. Finally, some corresponding control measures are suggested. Copyright © 2012 Elsevier Ltd. All rights reserved.

Tensile strength of solution-spun, ultradrawn ultrahigh-molecular-weight polyethylene fibers. 1. Influence of fiber diameter

OpenAIRE

Bastiaansen, C.W.M.

1992-01-01

The influence of fiber diam. on the tensile strength of soln.-spun, ultradrawn, ultrahigh-mol.-wt. polyethylene (UHMWPE, mol. wt. >103 kg/mol) fibers was studied. Fibers with a wide range of diams. were produced by varying the polymer concn. in soln. and by applying a drawdown to the fibers. The tensile strength of drawn fibers was compared at a const. Young's modulus in order to eliminate the influence of morphol. parameters, such as degree of chain orientation and extension, on the fracture...

Fabrication characteristics and strength of polymer-impregnated concrete polymerized by accelerated electron

International Nuclear Information System (INIS)

Ohgishi, Sakichi; Matsunaga, Katsumi; Ono, Hironobu; Iwamoto, Takeo.

1977-01-01

Since the accelerated electron has by far a higher dose rate than gamma-rays, the electron polymerizing method is more suitable for the efficient fabrication of polymer-impregnated concrete (PIC) with a thin cross section. However, there are few published papers on the manufacturing process of PIC polymerized by electron beam. This experiment was carried out to investigate the effects of density of cement mortar, dose rate of electron beam (4 MeV), total exposure dose and other factors which have influences upon the strength of MMA-PIC. The density of mortar, size of cross section of mortar specimens, dose rate of electron, total exposure dose and irradiating time interval were varied respectively as follow; rho=1.55 -- 3.13 g/cm 3 (the kinds of aggregates in cement mortar used are perlite, artificial light weight aggregate, normal river sand and iron sand), t=3.5 -- 40 mm in thickness, 0.55 or 1.10 Mrads/sec, 12.5 -- 100 Mrads per face, and 15 -- 60 sec/cycle. The test results of mechanical strength of PIC show that the optimum total exposure dose is about 40 Mrads at 0.55 Mrads/sec rate and 50 Mrads at 1.1 Mrads/sec in the ordinary mortar. It is also shown that the impregnation depth from the surface of specimen has a linear relation with the density of cement mortar, and that its depth is about 1 cm in conventional mortar. (auth.)

Strength and dynamic characteristics analyses of wound composite axial impeller

Science.gov (United States)

Wang, Jifeng; Olortegui-Yume, Jorge; Müller, Norbert

2012-03-01

A low cost, light weight, high performance composite material turbomachinery impeller with a uniquely designed blade patterns is analyzed. Such impellers can economically enable refrigeration plants to use water as a refrigerant (R718). A strength and dynamic characteristics analyses procedure is developed to assess the maximum stresses and natural frequencies of these wound composite axial impellers under operating loading conditions. Numerical simulation using FEM for two-dimensional and three-dimensional impellers was investigated. A commercially available software ANSYS is used for the finite element calculations. Analysis is done for different blade geometries and then suggestions are made for optimum design parameters. In order to avoid operating at resonance, which can make impellers suffer a significant reduction in the design life, the designer must calculate the natural frequency and modal shape of the impeller to analyze the dynamic characteristics. The results show that using composite Kevlar fiber/epoxy matrix enables the impeller to run at high tip speed and withstand the stresses, no critical speed will be matched during start-up and shut-down, and that mass imbalances of the impeller shall not pose a critical problem.

Is it good to be too light? Birth weight thresholds in hospital reimbursement systems.

Science.gov (United States)

Reif, Simon; Wichert, Sebastian; Wuppermann, Amelie

2018-02-02

Birth weight manipulation has been documented in per-case hospital reimbursement systems, in which hospitals receive more money for otherwise equal newborns with birth weight just below compared to just above specific birth weight thresholds. As hospitals receive more money for cases with weight below the thresholds, having a (reported) weight below a threshold could benefit the newborn. Also, these reimbursement thresholds overlap with diagnostic thresholds that have been shown to affect the quantity and quality of care that newborns receive. Based on the universe of hospital births in Germany from the years 2005-2011, we investigate whether weight below reimbursement relevant thresholds triggers different quantity and quality of care. We find that this is not the case, suggesting that hospitals' financial incentives with respect to birth weight do not directly impact the care that newborns receive. Copyright © 2018 Elsevier B.V. All rights reserved.

Discovering disease-associated genes in weighted protein-protein interaction networks

Science.gov (United States)

Cui, Ying; Cai, Meng; Stanley, H. Eugene

2018-04-01

Although there have been many network-based attempts to discover disease-associated genes, most of them have not taken edge weight - which quantifies their relative strength - into consideration. We use connection weights in a protein-protein interaction (PPI) network to locate disease-related genes. We analyze the topological properties of both weighted and unweighted PPI networks and design an improved random forest classifier to distinguish disease genes from non-disease genes. We use a cross-validation test to confirm that weighted networks are better able to discover disease-associated genes than unweighted networks, which indicates that including link weight in the analysis of network properties provides a better model of complex genotype-phenotype associations.

Energy-weighted moments in the problems of fragmentation

International Nuclear Information System (INIS)

Kuz'min, V.A.

1986-01-01

The problem of fragmentation of simple nuclear states on the complex ones is reduced to real symmetrical matrix eigenvectors and eigenvalue problem. Based on spectral decomposition of this matrix the simple and economical from computing point of view algorithm to calculate energetically-weighted strength function moments is obtained. This permitted one to investigate the sensitivity of solving the fragmentation problem to reducing the basis of complex states. It is shown that the full width of strength function is determined only by the complex states connected directly with the simple ones

Total edge irregularity strength of (n,t)-kite graph

Science.gov (United States)

Winarsih, Tri; Indriati, Diari

2018-04-01

Let G(V, E) be a simple, connected, and undirected graph with vertex set V and edge set E. A total k-labeling is a map that carries vertices and edges of a graph G into a set of positive integer labels {1, 2, …, k}. An edge irregular total k-labeling λ :V(G)\\cup E(G)\\to \\{1,2,\\ldots,k\\} of a graph G is a labeling of vertices and edges of G in such a way that for any different edges e and f, weights wt(e) and wt(f) are distinct. The weight wt(e) of an edge e = xy is the sum of the labels of vertices x and y and the label of the edge e. The total edge irregularity strength of G, tes(G), is defined as the minimum k for which a graph G has an edge irregular total k-labeling. An (n, t)-kite graph consist of a cycle of length n with a t-edge path (the tail) attached to one vertex of a cycle. In this paper, we investigate the total edge irregularity strength of the (n, t)-kite graph, with n > 3 and t > 1. We obtain the total edge irregularity strength of the (n, t)-kite graph is tes((n, t)-kite) = \\lceil \\frac{n+t+2}{3}\\rceil .

Beta Instability and Stochastic Market Weights

OpenAIRE

David H. Goldenberg

1985-01-01

An argument is given for individual firm beta instability based upon the stochastic character of the market weights defining the market portfolio and the constancy of its beta. This argument is generalized to market weighted portfolios and the form of the stochastic process generating betas is linked to that of the market return process. The implications of this analysis for adequacy of models of beta nonstationarity and estimation of betas are considered in light of the available empirical e...

Predictors of handgrip strength among adults of a rural community in Malaysia.

Science.gov (United States)

Moy, Foong-Ming; Darus, Azlan; Hairi, Noran Naqiah

2015-03-01

Handgrip strength is useful for screening the nutritional status of adult population as it is strongly associated with physical disabilities and mortality. Therefore, we aimed to determine the predictors of handgrip strength among adults of a rural community in Malaysia using a cross-sectional study design with multistage sampling. All adults aged 30 years and older from 1250 households were invited to our study. Structured questionnaire on sociodemographic characteristics, medical history, occupation history, lifestyle practices, and measurements, including anthropometry and handgrip strength were taken. There were 2199 respondents with 55.2% females and majority were of Malay ethnicity. Their mean (standard deviation) age was 53.4 (13.2) years. The response rate for handgrip strength was 94.2%. Females had significantly lower handgrip strength than males (P < .05). In the multiple linear regression models, significant predictors of handgrip strength for males were age, height, job groups, and diabetes, while for females, the significant predictors were age, weight, height, and diabetes. © 2013 APJPH.

Can exercise increase fitness and reduce weight in patients with schizophrenia and depression?

DEFF Research Database (Denmark)

Krogh, Jesper; Speyer, Helene; Nørgaard, Hans Christian Brix

2014-01-01

in this patient group and low levels of physical activity is associated with increased risk of cardiovascular disease, diabetes, and all-cause mortality. This study aimed to review trials allocating patients with either schizophrenia or depression to exercise interventions for effect on cardiovascular fitness......, strength, and weight. METHODS: We searched PubMed, Embase, and PsycINFO including randomized clinical trial allocating patients with either schizophrenia or depression to isolated exercise interventions. RESULTS: We identified five trials including patients with schizophrenia (n = 94) and found little...... evidence that exercise could increase cardiovascular fitness or decrease weight. Nine exercise trials for patients with depression (n = 892) were identified increasing cardiovascular fitness by 11-30% and strength by 33-37%. No evidence in favor of exercise for weight reduction was found. CONCLUSION: Based...

Weight Measurement Chitosan Molecule using GPC-MALLS

International Nuclear Information System (INIS)

Mohd Yusof Hamzah; Norhashidah Talip; Maznah Mahmud

2011-01-01

Research on basic characteristics and application of practical chitosan are need in order to understand their physical and chemical properties of this materials. One of the physico chemical properties that important for every polymers is absolute molecular weights. The important of this aspects has give big impacts on non colligative of the polymers, for example, viscosity, solubility and so on. Absolute weight molecular weights of each polymers can be measured by using GPC-MALLS. This device functioned as molecular size separator and molecular weight measurement by integration of the information such as sample concentration, light scattering index and sample reaction information using laser radiation irradiated from 18 angles.In this scope, we will discuss deeply on absolute weight molecular measurement of chitosan by using GPC-MALLS. (author)

Effect of Nanofiller Addition to an Experimental Dentin Adhesive on Microtensile Bond Strength to Human Dentin

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SH. Kasraei

2009-06-01

Full Text Available Objective: The purpose of the study was to evaluate the influence of adding nanofiller particles to a dentin bonding agent on resin-dentin bond strength.Materials and Methods: Fifty-four human intact premolar teeth were divided in to 6 groups of nine. The teeth were ground on occlusal surfaces and polished with 320 and then 600 grit silicon carbide papers. An experimental bonding system based on acetone/alcoholsolvent was provided with filler contents of 0.0, 0.5, 1.0, 2.5, 5.0, and 10.0 weight percent fumed silica nanofiller. After dentin surface etching, rinsing and blot drying, the experimentalbonding agents were applied to dentin surface. A composite resin was, then,bonded to the dentin on the bonding agent. The specimens were thermocycled for 500 cycles and sectioned in stick form. After two week of storage in distilled water, resin-dentin microtensile bond strength of the specimens was measured. Data were analyzed by one way ANOVA and DunnettT3 tests.Results: Bond strength to dentin was significantly affected by the filler level. Minimum and maximum resin-microtensile bond strength was in the experimental bonding agent with no filler (5.88 MPa and with filler level of 1.0 weight percent (15.15 MPa, respectively,and decreased with the increase of filler content down to 8.95 MPa for the filler level of 10.0 weight percent.Conclusion: Filler content seems to be one of the important factors influencing the bond strength of dental adhesives. Maximum dentin bond strength was obtained with 1% silanized nanofiller silica added to experimental adhesive system.

Lower extremity strength, systemic inflammation and all-cause mortality: Application to the "fat but fit" paradigm using cross-sectional and longitudinal designs.

Science.gov (United States)

Buckner, Samuel L; Loenneke, Jeremy P; Loprinzi, Paul D

2015-10-01

No study has applied the "fat-but-fit" paradigm with respect to muscular strength as an index of fitness, despite muscular strength being independently associated with functional ability and mortality. To examine the relationship between lower extremity muscular strength, C-reactive protein (CRP), and all-cause mortality among normal weight, overweight and obese individuals. Data from the 1999-2002 NHANES were used (N=2740 adults; ≥ 50 years). CRP values were obtained from a blood sample. Lower body isokinetic knee extensor strength (IKES) was assessed using a Kin Kom MP isokinetic dynamometer. Participant data was linked to death certificate data from the National Death Index to ascertain all-cause mortality status. Participants were classified, based on body mass index (BMI) and strength as: normal weight and unfit (fit (≥ 75th IKES percentile); overweight and fit; and obese and fit. Independent of physical activity and other confounders, compared to those who were normal weight and unfit, unfit overweight (β=.14, p=0.009), unfit obese (β=.33, pfit (β=.17, p=0.008) participants, had higher CRP levels. However, there was no difference in CRP levels between normal weight and unfit participants and overweight and fit participants (β=0.04, p=0.35). Compared to normal weight unfit adults, overweight fit (HR=0.28; 95% CI: 0.11-0.70; p=0.008) adults had a lower hazard rate for all-cause mortality. These finding suggest that increased lower body strength, independent of physical activity, may reduce premature all-cause mortality and attenuate systemic inflammation among overweight adults. Copyright © 2015 Elsevier Inc. All rights reserved.

The influence of using accelerator addition on High strength self-compacting concrete (HSSCC) in case of enhancement early compressive strength and filling ability parameters

Science.gov (United States)

Wibowo; Fadillah, Y.

2018-03-01

Efficiency in a construction works is a very important thing. Concrete with ease of workmanship and rapid achievement of service strength will to determine the level of efficiency. In this research, we studied the optimization of accelerator usage in achieving performance on compressive strength of concrete in function of time. The addition of variation of 0.3% - 2.3% to the weight of cement gives a positive impact of the rapid achievement of hardened concrete, however the speed of increasing of concrete strength achievement in term of time influence present increasing value of filling ability parameter of self-compacting concrete. The right composition of accelerator aligned with range of the values standard of filling ability parameters of HSSCC will be an advantage guidance for producers in the ready-mix concrete industry.

Association with isokinetic ankle strength measurements and normal clinical muscle testing in sciatica patients.

Science.gov (United States)

Ustun, N; Erol, O; Ozcakar, L; Ceceli, E; Ciner, O Akar; Yorgancioglu, Z R

2013-01-01

Sensitive muscle strength tests are needed to measure muscle strength in the diagnosis and management of sciatica patients. The aim of this study was to assess the isokinetic muscle strength in sciatica patients' and control subjects' ankles that exhibited normal ankle muscle strength when measured clinically. Forty-six patients with L5 and/or S1 nerve compression, and whose age, sex, weight, and height matched 36 healthy volunteers, were recruited to the study. Heel-walking, toe-walking, and manual muscle testing were used to perform ankle dorsiflexion and plantar flexion strengths in clinical examination. Patients with normal ankle dorsiflexion and plantar flexion strengths assessed by manual muscle testing and heel-and toe-walking tests were included in the study. Bilateral isokinetic (concentric/concentric) ankle plantar-flexion-dorsiflexion measurements of the patients and controls were performed within the protocol of 30°/sec (5 repetitions). Peak torque and peak torque/body weight were obtained for each ankle motion of the involved limb at 30°/s speed. L5 and/or S1 nerve compression was evident in 46 patients (76 injured limbs). Mean disease duration was two years. The plantar flexion muscle strength of the patients was found to be lower than that of the controls (p=0.036). The dorsiflexion muscle strength of the patients was found to be the same as that of the controls (p=0.211). Isokinetic testing is superior to clinical muscle testing when evaluating ankle plantar flexion torque in sciatica patients. Therefore, isokinetic muscle testing may be helpful when deciding whether to place a patient into a focused rehabilitation program.

Effect of blood contamination with 1-step self-etching adhesives on microtensile bond strength to dentin.

Science.gov (United States)

Yoo, H M; Pereira, P N R

2006-01-01

This study evaluated the effect of blood contamination and decontamination methods on the microtensile bond strength of 1-step self-etching adhesive systems to dentin contaminated after adhesive application and light curing. Three commercially available "all-in-one" adhesives (One Up Bond F, Xeno III and Adper Prompt L-Pop) and 1 resin composite (Clearfil AP-X) were used. Third molars that had been stored in distilled water with 0.5% thymol at 4 degrees C were ground with #600 SiC paper under running water to produce a standardized smear layer. The specimens were randomly divided into groups according to the 3 adhesive systems. The adhesive systems were used under 3 conditions: no contamination, which was the control (C); contamination of the light-cured adhesive surface with blood and reapplication of adhesive (Contamination 1) and contamination of the light-cured adhesive surface with blood, then washing, drying and reapplication of the adhesive (Contamination 2). Following light curing of the adhesive, the resin composite was placed in 3 increments up to a 5-mm-thick layer on the bonded surface. All specimens were stored in distilled water at 37 degrees C for 24 hours. The microtensile bond strength was measured using a universal testing machine (EZ test), and data were analyzed by 1-way ANOVA followed by the Duncan test to make comparisons among the groups (p=0.05). After debonding, 5 specimens were selected from each group and examined in a scanning electron microscope to evaluate the modes of fracture. For all adhesives, contamination groups showed lower bond strength than the control (p0.05). For Xeno III and Adper Prompt L-Pop, contamination group #2 showed the lowest bond strength among the groups (pcontamination group #2 showed higher bond strength than contamination group #1 but showed no statistical significance between them (p>0.05).

Study on Design of High Efficiency and Light Weight Composite Propeller Blade for a Regional Turboprop Aircraft

Science.gov (United States)

Kong, Changduk; Lee, Kyungsun

2013-03-01

In this study, aerodynamic and structural design of the composite propeller blade for a regional turboprop aircraft is performed. The thin and wide chord propeller blade of high speed turboprop aircraft should have proper strength and stiffness to carry various kinds of loads such as high aerodynamic bending and twisting moments and centrifugal forces. Therefore the skin-spar-foam sandwich structure using high strength and stiffness carbon/epoxy composite materials is used to improve the lightness. A specific design procedure is proposed in this work as follows; firstly the aerodynamic configuration design, which is acceptable for the design requirements, is carried out using the in-house code developed by authors, secondly the structure design loads are determined through the aerodynamic load case analysis, thirdly the spar flange and the skin are preliminarily sized by consideration of major bending moments and shear forces using both the netting rule and the rule of mixture, and finally, the stress analysis is performed to confirm the structural safety and stability using finite element analysis commercial code, MSC. NASTRAN/PATRAN. Furthermore the additional analysis is performed to confirm the structural safety due to bird strike impact on the blade during flight operation using a commercial code, ANSYS. To realize the proposed propeller design, the prototype blades are manufactured by the following procedure; the carbon/epoxy composite fabric prepregs are laid up for skin and spar on a mold using the hand lay-up method and consolidated with a proper temperature and vacuum in the oven. To finalize the structural design, the full-scale static structural test is performed under the simulated aerodynamic loads using 3 point loading method. From the experimental results, it is found that the designed blade has a good structural integrity, and the measured results agree well with the analytical results as well.

Pelvic floor muscle strength in primiparous women according to the delivery type: cross-sectional study

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Edilaine de Paula Batista Mendes

Full Text Available ABSTRACT Objectives: to compare the pelvic floor muscle strength in primiparous women after normal birth and cesarean section, related to the socio-demographic characteristics, nutritional status, dyspareunia, urinary incontinence, perineal exercise in pregnancy, perineal condition and weight of the newborn. Methods: this was a cross-sectional study conducted after 50 - 70 postpartum days, with 24 primiparous women who underwent cesarean delivery and 72 who had a normal birth. The 9301 PeritronTM was used for analysis of muscle strength. The mean muscle strength was compared between the groups by two-way analysis of variance. Results: the pelvic floor muscle strength was 24.0 cmH2O (±16.2 and 25.4 cmH2O (±14.7 in postpartum primiparous women after normal birth and cesarean section, respectively, with no significant difference. The muscular strength was greater in postpartum women with ≥ 12 years of study (42.0 ±26.3 versus 14.6 ±7.7 cmH2O; p= 0.036 and in those who performed perineal exercises (42.6±25.4 11.8±4.9 vs. cmH2O; p = 0.010, compared to caesarean. There was no difference in muscle strength according to delivery type regarding nutritional status, dyspareunia, urinary incontinence, perineal condition or newborn weight. Conclusion: pelvic floor muscle strength does not differ between primiparous women based on the type of delivery. Postpartum women with normal births, with higher education who performed perineal exercise during pregnancy showed greater muscle strength.

Effects of external environments on the short beam shear strength of filament wound graphite/epoxy

Science.gov (United States)

Penn, B. G.; Clemons, J. M.

1986-01-01

Filament wound graphite/epoxy samples were immersed in seawater, deionized water, and toluene at room temperature and 80 deg C for 5, 15, and 43 days, and in methanol at room temperature for 15 and 43 days. The percent weight gains and short beam shear strengths were determined after environmental exposure. Samples immersed in deionized water and seawater had higher percent weight gains than those immersed in toluene at room temperature and 80 deg C. The percent weight gains for samples immersed in methanol at room temperature were comparable to those of deionized water and seawater immersed samples. A comparison of percent decreases in short beam shear strengths could not be made due to a large scatter in data. This may indicate defects in samples due to machining or variations in material properties due to processing.

Association between muscle strength and metabolic syndrome in older Korean men and women: the Korean Longitudinal Study on Health and Aging.

Science.gov (United States)

Yang, Eun Joo; Lim, Soo; Lim, Jae-Young; Kim, Ki Woong; Jang, Hak Chul; Paik, Nam-Jong

2012-03-01

The objective of the study was to investigate the association between metabolic syndrome (MS) and muscle strength in community-dwelling older men and women in Korea. Korean men and women 65 years and older living in a single, typical South Korean city (n = 647) were enrolled in the Korean Longitudinal Study on Health and Aging study. The diagnosis of MS was evaluated according to the definition of the National Cholesterol Education Program Adult Treatment Panel III. Isokinetic muscle strength of the knee extensors, as determined by peak torque per body weight (newton meter per kilogram) and hand-grip strength per body weight (newton per kilogram), was measured. Participants without MS had greater leg muscle strength and grip strength per weight. The effect of MS on muscle strength was more prominent in men than in women in our study population. Only men showed a significant interaction between MS and age for muscle strength (P = .014), and the effect was greater in men aged 65 to 74 years compared with those older than 75 years (119.2 ± 31.2 vs 134.5 ± 24.3 N m/kg). Participants with MS had weaker knee extensor strength after controlling the covariates (β = -90.80, P = .003), and the interaction term (age × MS × male sex) was significant (β = 1.00, P = .017). Metabolic syndrome is associated with muscle weakness, and this relationship is particularly pronounced in men. Age can modify the impact of MS on muscle strength. Men aged 65 to 74 years with MS need a thorough assessment of muscle strength to prevent disability. Copyright © 2012 Elsevier Inc. All rights reserved.

Cyanogen strengths of globular cluster post-main-sequence stars

International Nuclear Information System (INIS)

Hesser, J.E.; Hartwick, F.D.A.; McClure, R.D.

1976-01-01

CN strengths in the peculiar clusters ω Cen and M22 and the metal-rich clusters 47 Tuc, M71, and NGC 6352 are found to vary markedly from star to star. The strong variations in CN strength found earlier for ω Cen by Norris and Bessell and by Dickens and Bell are shown to extend to fainter stars, although expected correlations of CN strength with position in the color-magnitude (C-M) diagram are less evident in our sample. Several CN and metal-strong stars were also observed in M22. We conclude that CN, once it appears in globular clusters, can vary much more than it does in equivalent Population I samples, a result we briefly examine in light of current understanding regarding physical processes in the stars themselves and of models of galactic chemical evolution

PHYSICAL FITNESS AND BIRTH WEIGHT IN YOUNG MEN FROM MAPUTO CITY, MOZAMBIQUE

Directory of Open Access Journals (Sweden)

Mario Eugénio Tchamo

2016-02-01

Full Text Available ABSTRACT Introduction: Birth weight has been considered an important marker of the nutritional transition in developing countries. Objective: To evaluate the influence of birth weight on body composition and physical fitness of young men born in Maputo, Mozambique. Methods: One hundred and seventy-nine students (aged 19 to 22 years were divided into four groups (low birth weight 3.999 g, HBW, n = 31. Anthropometry and body composition were measured. Physical fitness was assessed by handgrip strength, muscle endurance, flexibility, agility, and running speed. Results: IBW showed lower values of body mass and fat free mass while LBW and HBW had high values of hip circumference, suprailiac, subscapular and abdominal skinfold when compared to NBW. LBW and HBW showed a high percentage of individuals with low performance in flexibility, right handgrip, agility, abdominal resistance, arms strength, and horizontal long jump. Around 70% of HBW showed low performance in the running speed test. Conclusion: Both low and high birth weight can influence adult adiposity and the performance in physical fitness tests.

Time perspective and weight management behaviors in newly diagnosed Type 2 diabetes: a mediational analysis.

Science.gov (United States)

Hall, Peter A; Fong, Geoffrey T; Cheng, Alice Y

2012-12-01

The primary objective of the current study was to examine the extent to which domain-specific time perspective predicts weight management behaviors (dietary behavior and physical activity) among those newly diagnosed with Type 2 diabetes. A secondary objective was to test potential mediators of the hypothesized effect (behavioral intention, self-efficacy and control beliefs). A total of 204 adults newly diagnosed (≤6 months) with Type 2 diabetes participated in the study, which included a baseline assessment of domain-general and domain-specific time perspective, as well as strength of intention to perform two weight-management behaviors (dietary choice and physical activity); both weight-management behaviors were assessed again at 6 month follow-up. Hierarchical multiple regression analyses revealed a prospective association between domain-specific time perspective and uptake of weight management behaviors. Individuals with newly diagnosed T2DM possessing a future-oriented time perspective reported making less frequent fatty food choices and greater increases in physical activity over the 6-month follow-up interval. These effects were selectively mediated by intention strength, and not competing social cognitive variables. For both behaviors, the total effects and meditational models were robust to adjustments for demographics, body composition and disease variables. A future-oriented time perspective is prospectively associated with superior uptake of weight management behaviors among those with newly diagnosed Type 2 diabetes. The facilitating effect of future-oriented thinking appears to occur via enhanced strength of intentions to perform weight management behaviors.

Spectral characterization of plastic scintillation detector response as a function of magnetic field strength

Science.gov (United States)

Simiele, E.; Kapsch, R.-P.; Ankerhold, U.; Culberson, W.; DeWerd, L.

2018-04-01

The purpose of this work was to characterize intensity and spectral response changes in a plastic scintillation detector (PSD) as a function of magnetic field strength. Spectra measurements as a function of magnetic field strength were performed using an optical spectrometer. The response of both a PSD and PMMA fiber were investigated to isolate the changes in response from the scintillator and the noise signal as a function of magnetic field strength. All irradiations were performed in water at a photon beam energy of 6 MV. Magnetic field strengths of (0, ±0.35, ±0.70, ±1.05, and  ±1.40) T were investigated. Four noise subtraction techniques were investigated to evaluate the impact on the resulting noise-subtracted scintillator response with magnetic field strength. The noise subtraction methods included direct spectral subtraction, the spectral method, and variants thereof. The PMMA fiber exhibited changes in response of up to 50% with magnetic field strength due to the directional light emission from \\breve{C} erenkov radiation. The PSD showed increases in response of up to 10% when not corrected for the noise signal, which agrees with previous investigations of scintillator response in magnetic fields. Decreases in the \\breve{C} erenkov light ratio with negative field strength were observed with a maximum change at  ‑1.40 T of 3.2% compared to 0 T. The change in the noise-subtracted PSD response as a function of magnetic field strength varied with the noise subtraction technique used. Even after noise subtraction, the PSD exhibited changes in response of up to 5.5% over the four noise subtraction methods investigated.

Some considerations about improvement for fatigue strength of structures; Shatai kozobutsu no hiro kyodo kojo ni kansuru ichikosatsu

Energy Technology Data Exchange (ETDEWEB)

Kimoto, H; Toyama, K; Maruyama, H; Magara, S [Press Kogyo Co. Ltd., Kanagawa (Japan)

1997-10-01

To reduce weight, higher tensile strength and/or thinner plate are used or considered in vehicle structures. In general, welded or notch sections, fatigue strength decreases because of increasing concentrated stress or effect of notch sensitivity and so on. In this paper, some methods are studied to improve fatigue strength and obtain a long life. 2 refs., 11 figs., 5 tabs.

STOCHASTIC MODELING OF COMPRESSIVE STRENGTH OF PHOSPHORUS SLAG CONTENT CEMENT

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Ali Allahverdi

2016-07-01

Full Text Available One of the common methods for quick determination of compressive strength as one of the most important properties for assessment of cement quality is to apply various modeling approaches. This study is aimed at finding a model for estimating the compressive strength of phosphorus slag content cements. For this purpose, the compressive strengths of chemically activated high phosphorus slag content cement prepared from phosphorus slag (80 wt.%, Portland cement (14 wt.% and a compound chemical activator containing sodium sulfate and anhydrite (6 wt.% were measured at various Blaine finenesses and curing times. Based on the obtained results, a primary stochastic model in terms of curing time and Blaine fineness has been developed. Then, another different dataset was used to incorporate composition variable including weight fractions of phosphorus slag, cement, and activator in the model. This model can be effectively used to predict the compressive strength of phosphorus slag content cements at various Blaine finenesses, curing times, and compositions.

Wood strength loss as a measure of decomposition in northern forest mineral soil

Science.gov (United States)

Martin Jurgensen; David Reed; Deborah Page-Dumroese; Peter Laks; Anne Collins; Glenn Mroz; Marek Degorski

2006-01-01

Wood stake weight loss has been used as an index of wood decomposition in mineral soil, but it may not give a reliable estimate in cold boreal forests where decomposition is very slow.Various wood stake strength tests have been used as surrogates of weight loss, but little is known on which test would give the best estimate of decomposition over a variety of soil...

Degree of conversion and bond strength of resin-cements to feldspathic ceramic using different curing modes

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Veridiana Resende NOVAIS

Full Text Available Abstract Resin cements have led to great advances in dental ceramic restoration techniques because of their ability to bond to both dental structures and restorative materials. Objective The aim of this study was to assess the performance of resin cements when different curing modes are used, by evaluating the degree of conversion and bond strength to a ceramic substrate. Material and Methods Three resin cements were evaluated, two dual-cured (Variolink II and RelyX ARC and one light-cured (Variolink Veneer. The dual-cured resin cements were tested by using the dual activation mode (base and catalyst and light-activation mode (base paste only. For degree of conversion (DC (n=5, a 1.0 mm thick feldspathic ceramic disc was placed over the resin cement specimens and the set was light activated with a QTH unit. After 24 h storage, the DC was measured with Fourier transform infrared spectroscopy (FTIR. For microshear bond strength testing, five feldspathic ceramic discs were submitted to surface treatment, and three cylindrical resin cement specimens were bonded to each ceramic surface according to the experimental groups. After 24 h, microshear bond testing was performed at 0.5 mm/min crosshead speed until the failure. Data were submitted to one-way ANOVA followed by Tukey test (p<0.05. Scanning electron microscopy (SEM was used for classifying the failure modes. Results Higher DC and bond strength values were shown by the resin cements cured by using the dual activation mode. The Variolink II group presented higher DC and bond strength values when using light-activation only when compared with the Variolink Veneer group. Conclusion The base paste of dual-cured resin cements in light-activation mode can be used for bonding translucent ceramic restorations of up to or less than 1.0 mm thick.

Effect of saliva decontamination procedures on shear bond strength of a one-step adhesive system.

Science.gov (United States)

Ülker, E; Bilgin, S; Kahvecioğlu, F; Erkan, A I

2017-09-01

To evaluate the effect of different saliva decontamination procedures on the shear bond strength of a one-step universal adhesive system (Single Bond™ Universal Adhesive, 3M ESPE, St. Paul, MN, USA). The occlusal surfaces of 75 human third molars were ground to expose dentin. The teeth were divided into the following groups: Group 1 (control group): Single Bond™ Universal Adhesive was applied to the prepared tooth according to the manufacturer's recommendations and light cured; no contamination procedure was performed. Group 2: Bonding, light curing, saliva contamination, and dry. Group 3: Bonding, light curing, saliva contamination, rinse, and dry. Group 4: After the procedure performed in Group 2, reapplication of bonding. Group 5: After the procedure performed in Group 3, reapplication of bonding. Then, composite resins were applied with cylindrical-shaped plastic matrixes and light cured. For shear bond testing, a notch-shaped force transducer apparatus was applied to each specimen at the interface between the tooth and composite until failure occurred. The data were statistically analyzed using one-way ANOVA. One-way ANOVA revealed significant differences in shear bond strength between the control group and experimental Groups 2 and 4 (P 0.05). The present in vitro study showed that water rinsing is necessary if cured adhesive resin is contaminated with saliva to ensure adequate bond strength.

Light scattering measurements supporting helical structures for chromatin in solution.

Science.gov (United States)

Campbell, A M; Cotter, R I; Pardon, J F

1978-05-01

Laser light scattering measurements have been made on a series of polynucleosomes containing from 50 to 150 nucleosomes. Radii of gyration have been determined as a function of polynucleosome length for different ionic strength solutions. The results suggest that at low ionic strength the chromatin adopts a loosely helical structure rather than a random coil. The helix becomes more regular on increasing the ionic strength, the dimension resembling those proposed by Finch and Klug for their solenoid model.

Heat treatment of a direct composite resin: influence on flexural strength

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Caroline Lumi Miyazaki

2009-09-01

Full Text Available The purpose of this study was to evaluate the flexural strength of a direct composite, for indirect application, that received heat treatment, with or without investment. One indirect composite was used for comparison. For determination of the heat treatment temperature, thermogravimetric analysis (TGA and differential scanning calorimetry (DSC were performed, considering the initial weight loss temperature and glass transition temperature (Tg. Then, after photoactivation (600 mW/cm² - 40 s, the specimens (10 x 2 x 2 mm were heat-treated following these conditions: 170ºC for 5, 10 or 15 min, embedded or not embedded in investment. Flexural strength was assessed as a means to evaluate the influence of different heat treatment periods and investment embedding on mechanical properties. The data were analyzed by ANOVA and Tukey's test (α = 0.05. TGA showed an initial weight loss temperature of 180ºC and DSC showed a Tg value of 157°C. Heat treatment was conducted in an oven (Flli Manfredi, Italy, after 37°C storage for 48 h. Flexural strength was evaluated after 120 h at 37°C storage. The results showed that different periods and investment embedding presented similar statistical values. Nevertheless, the direct composite resin with treatments presented higher values (178.7 MPa compared to the indirect composite resin (146.0 MPa and the same direct composite submitted to photoactivation only (151.7 MPa. Within the limitations of this study, it could be concluded that the heat treatment increased the flexural strength of the direct composite studied, leading to higher mechanical strength compared to the indirect composite.

Effects of exercise training using resistance bands on glycaemic control and strength in type 2 diabetes mellitus: a meta-analysis of randomised controlled trials.

Science.gov (United States)

McGinley, Samantha K; Armstrong, Marni J; Boulé, Normand G; Sigal, Ronald J

2015-04-01

Resistance exercise using free weights or weight machines improves glycaemic control and strength in people with type 2 diabetes. Resistance band training is potentially less expensive and more accessible, but the effects of resistance band training on glycaemic control and strength in this population are not well understood. This paper aims to systematically review and meta-analyse the effect of resistance band training on haemoglobin A1c (HbA1c) and strength in adults with type 2 diabetes. Database searches were performed in August 2013 (MEDLINE, SPORTDiscus, EMBASE, and CINAHL). Reference lists of eligible articles were hand-searched for additional studies. Randomised trials evaluating the effects of resistance band training in adults with type 2 diabetes on HbA1c or objectively measured strength were selected. Baseline and post-intervention HbA1c and strength were extracted for the intervention and control groups. Details of the exercise interventions and methodological quality were collected. Seven trials met inclusion criteria. Post-intervention-weighted mean HbA1c was nonsignificantly lower in exercise groups compared to control groups [weighted mean difference (WMD) = -0.18 percentage points (-1.91 mmol/mol); P = 0.27]. Post-intervention strength was significantly higher in the exercise groups compared to the control groups in the lower extremities (WMD = 21.90 kg; P diabetes.

Preliminary structural design of composite main rotor blades for minimum weight

Science.gov (United States)

Nixon, Mark W.

1987-01-01

A methodology is developed to perform minimum weight structural design for composite or metallic main rotor blades subject to aerodynamic performance, material strength, autorotation, and frequency constraints. The constraints and load cases are developed such that the final preliminary rotor design will satisfy U.S. Army military specifications, as well as take advantage of the versatility of composite materials. A minimum weight design is first developed subject to satisfying the aerodynamic performance, strength, and autorotation constraints for all static load cases. The minimum weight design is then dynamically tuned to avoid resonant frequencies occurring at the design rotor speed. With this methodology, three rotor blade designs were developed based on the geometry of the UH-60A Black Hawk titanium-spar rotor blade. The first design is of a single titanium-spar cross section, which is compared with the UH-60A Black Hawk rotor blade. The second and third designs use single and multiple graphite/epoxy-spar cross sections. These are compared with the titanium-spar design to demonstrate weight savings from use of this design methodology in conjunction with advanced composite materials.

The effect of shredding and test apparatus size on compressibility and strength parameters of degraded municipal solid waste.

Science.gov (United States)

Hossain, M S; Gabr, M A; Asce, F

2009-09-01

In many situations, MSW components are processed and shredded before use in laboratory experiments using conventional soil testing apparatus. However, shredding MSW material may affect the target property to be measured. The objective of this study is to contribute to the understanding of the effect of shredding of MSW on the measured compressibility and strength properties. It is hypothesized that measured properties can be correlated to an R-value, the ratio of waste particle size to apparatus size. Results from oedometer tests, conducted on 63.5 mm, 100 mm, 200 mm diameter apparatus, indicated the dependency of the compressibility parameters on R-value. The compressibility parameters are similar for the same R-value even though the apparatus size varies. The results using same apparatus size with variable R-values indicated that shredding of MSW mainly affects initial compression. Creep and biological strain rate of the tested MSW are not significantly affected by R-value. The shear strength is affected by shredding as the light-weight reinforcing materials are shredded into smaller pieces during specimen preparation. For example, the measured friction angles are 32 degrees and 27 degrees for maximum particle sizes of 50 mm and 25 mm, respectively. The larger MSW components in the specimen provide better reinforcing contribution. This conclusion is however dependent on comparing specimen at the same level of degradation since shear strength is also a function of extent of degradation.

Modification of Bonding Strength Test of WC HVOF Thermal Spray Coating on Rocket Nozzle

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Bondan Sofyan

2010-10-01

Full Text Available One way to reduce structural weight of RX-100 rocket is by modifying the nozzle material and processing. Nozzle is the main target in weight reduction due to the fact that it contributes 30 % to the total weight of the structur. An alternative for this is by substitution of massive graphite, which is currently used as thermal protector in the nozzle, with thin layer of HVOF (High Velocity Oxy-Fuel thermal spray layer. This paper presents the characterization of nozzle base material as well as the modification of bonding strength test, by designing additional jig to facilitate testing processes while maintaining level of test accuracy. The results showed that the material used for  RX-100 rocket nozzle is confirmed to be S45C steel. Modification of the bonding strength test was conducted by utilizing chains, which improve test flexibility and maintains level of accuracy of the test.

Effect of solution temperature, light intensity and light in combination with sunlight using mirror duct on growth of leaf lettuce (Lactuca savtiva L. cv. 'Greenwave')

International Nuclear Information System (INIS)

Shimizu, H.; Kushida, M.; Fujinuma, W.; Sekine, M.; Kaiho, K.; Arai, H.; Shibusawa, S.

2004-01-01

Leaf lettuce crops (Lactuca sativa L. cv. 'Greenwave') were grown in a plant production system using a Mirror Duct which intensified sunlight and transferred it to the inside of buildings. This system was expected to reduce the operational energy and lighting cost. The experiments were conducted under four photosynthetic photon flux densities (PPF) of 140,160, 180, and 200 micro mol mE-2 sE-1, in two light conditions, fluorescent light only and fluorescent light plus sunlight transferred with the Mirror Duct, and were repeated five times in total from August 2002 to July 2003. Five different solution temperatures were finally obtained through all the experiments due to temperature changes inside the experiment facility. Variance was analyzed to estimate the effect of these environmental factors on the growth of leaf lettuce. It was found that the fresh weight of leaf lettuce increased as PPF increased and the rate of increase of weight was 0.6 to 1.0 g per unit PPF in both 17.4 deg C and 23.5 deg C solution temperatures; the solution temperature had a significant effect upon the fresh weight; and a difference in fresh weight at harvest of between 40 and 60 g was observed between 17.4 deg C and 23.5 deg C solution temperatures. The light containing 10% sunlight was not effective for increasing fresh weight at harvest compared to the fluorescent lamp

Can exercise increase fitness and reduce weight in patients with schizophrenia and depression?

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Jesper eKrogh

2014-07-01

Full Text Available BackgroundPsychiatric patients have a reduced life expectancy of 15 to 20 years compared to the general population. Most years of lost life are due to excess mortality from somatic diseases. Sedentary lifestyle and medication is partly responsible for the high frequency of metabolic syndrome in this patient group and low levels of physical activity is associated with increased risk of cardiovascular disease, diabetes and all-cause mortality. This study aimed to review trials allocating patients with either schizophrenia or depression to exercise interventions for effect on cardiovascular fitness, strength and weight.MethodsWe searched Pubmed, Embase, and Psycinfo including randomized clinical trial allocating patients with either schizophrenia or depression to isolated exercise interventions.ResultsWe identified five trials including patients with schizophrenia and found little evidence that exercise could increase cardiovascular fitness or decrease weight. Nine exercise trials for patients with depression were identified increasing cardiovascular fitness by 11-30% and strength by 33-37%. No evidence in favor of exercise for weight reduction was found.ConclusionBased on the current evidence isolated exercise interventions are unlikely to improve cardiovascular fitness or induce weight loss in patients with schizophrenia. In patients with depression exercise interventions are likely to induce clinically relevant short term effects, however, due to lack of reporting little is known about the effect on cardiovascular fitness beyond the intervention and weight reduction. Future exercise trials regarding patients with mental illness should preferably measure changes in cardiovascular strength, repetition maximum and anthropometric outcomes. Ideally participants should be assessed beyond the intervention

An Approach for Measuring the Dielectric Strength of OLED Materials

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Sujith Sudheendran Swayamprabha

2018-06-01

Full Text Available Surface roughness of electrodes plays a key role in the dielectric breakdown of thin-film organic devices. The rate of breakdown will increase when there are stochastic sharp spikes on the surface of electrodes. Additionally, surface having spiking morphology makes the determination of dielectric strength very challenging, specifically when the layer is relatively thin. We demonstrate here a new approach to investigate the dielectric strength of organic thin films for organic light-emitting diodes (OLEDs. The thin films were deposited on a substrate using physical vapor deposition (PVD under high vacuum. The device architectures used were glass substrate/indium tin oxide (ITO/organic material/aluminum (Al and glass substrate/Al/organic material/Al. The dielectric strength of the OLED materials was evaluated from the measured breakdown voltage and layer thickness.

Edge states and phase diagram for graphene under polarized light

Energy Technology Data Exchange (ETDEWEB)

Wang, Yi-Xiang, E-mail: wangyixiang@jiangnan.edu.cn [School of Science, Jiangnan University, Wuxi 214122 (China); Li, Fuxiang [Center for Nonlinear Studies and Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

2016-07-01

In this work, we investigate the topological phase transitions in graphene under the modulation of circularly polarized light, by analyzing the changes of edge states and its topological structures. A full phase diagram, with several different topological phases, is presented in the parameter space spanned by the driving frequency and light strength. We find that the high-Chern number behavior is very common in the driven system. While the one-photon resonance can create the chiral edge states in the π-gap, the two-photon resonance will induce the counter-propagating edge modes in the zero-energy gap. When the driving light strength is strong, the number and even the chirality of the edge states may change in the π-gap. The robustness of the edge states to disorder potential is also examined. We close by discussing the feasibility of experimental proposals.

LED Lighting – Modification of Growth, Metabolism, Yield and Flour Composition in Wheat by Spectral Quality and Intensity

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István Monostori

2018-05-01

Full Text Available The use of light-emitting diode (LED technology for plant cultivation under controlled environmental conditions can result in significant reductions in energy consumption. However, there is still a lack of detailed information on the lighting conditions required for optimal growth of different plant species and the effects of light intensity and spectral composition on plant metabolism and nutritional quality. In the present study, wheat plants were grown under six regimens designed to compare the effects of LED and conventional fluorescent lights on growth and development, leaf photosynthesis, thiol and amino acid metabolism as well as grain yield and flour quality of wheat. Benefits of LED light sources over fluorescent lighting were manifested in both yield and quality of wheat. Elevated light intensities made possible with LEDs increased photosynthetic activity, the number of tillers, biomass and yield. At lower light intensities, blue, green and far-red light operated antagonistically during the stem elongation period. High photosynthetic activity was achieved when at least 50% of red light was applied during cultivation. A high proportion of blue light prolonged the juvenile phase, while the shortest flowering time was achieved when the blue to red ratio was around one. Blue and far-red light affected the glutathione- and proline-dependent redox environment in leaves. LEDs, especially in Blue, Pink and Red Low Light (RedLL regimens improved flour quality by modifying starch and protein content, dough strength and extensibility as demonstrated by the ratios of high to low molecular weight glutenins, ratios of glutenins to gliadins and gluten spread values. These results clearly show that LEDs are efficient for experimental wheat cultivation, and make it possible to optimize the growth conditions and to manipulate metabolism, yield and quality through modification of light quality and quantity.

Effects of blood contamination on resin-resin bond strength.

Science.gov (United States)

Eiriksson, Sigurdur O; Pereira, Patricia N R; Swift, Edward J; Heymann, Harald O; Sigurdsson, Asgeir

2004-02-01

Incremental placement and curing of resin composites has been recommended. However, this requires longer operating time, and therefore, increased risk of contamination. The purpose of this study was to evaluate the effects of blood contamination on microtensile bond strengths (microTBS) between resin interfaces and to determine the best decontamination method to re-establish the original resin-resin bond strength. The top surfaces of 64, 4-mm composite blocks (Z-250, Renew, APX, Pertac II) were untreated as the control, or were treated as follows: blood applied and dried on the surface (Treatment 1), blood applied, rinsed, dried (Treatment 2), blood applied, rinsed, and an adhesive applied (Single Bond, One-Step, Clearfil SE, Prompt L-Pop) (Treatment 3). Fresh composite was applied and light-cured in 2-mm increments. After 24 h storage in water, the specimens were sectioned into 0.7-mm thick slabs, trimmed to a cross-sectional area of 1 mm(2), and loaded to failure at a crosshead speed of 1 mm/min using an Instron universal testing machine. Data were analyzed using two-way ANOVA and Fisher's PLSD test (pcontamination resulted in resin-resin bond strengths of only 1.0-13.1 MPa. Rinsing raised bond strengths to over 40 MPa for each material. Use of an adhesive further increased bond strengths except for Pertac II. Rinsing blood from contaminated surfaces increases the resin-resin bond strength significantly and the application of an appropriate adhesive increases the bond strength to control levels.

Randomizing world trade. II. A weighted network analysis

Science.gov (United States)

Squartini, Tiziano; Fagiolo, Giorgio; Garlaschelli, Diego

2011-10-01

Based on the misleading expectation that weighted network properties always offer a more complete description than purely topological ones, current economic models of the International Trade Network (ITN) generally aim at explaining local weighted properties, not local binary ones. Here we complement our analysis of the binary projections of the ITN by considering its weighted representations. We show that, unlike the binary case, all possible weighted representations of the ITN (directed and undirected, aggregated and disaggregated) cannot be traced back to local country-specific properties, which are therefore of limited informativeness. Our two papers show that traditional macroeconomic approaches systematically fail to capture the key properties of the ITN. In the binary case, they do not focus on the degree sequence and hence cannot characterize or replicate higher-order properties. In the weighted case, they generally focus on the strength sequence, but the knowledge of the latter is not enough in order to understand or reproduce indirect effects.

Body Build and the Level of Development of Muscle Strength Among Male Jiu-Jitsu Competitors and Strength-Trained Adults

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Pietraszewska Jadwiga

2014-09-01

differences between the jiu-jitsu and strength-training groups may be due to the different sporting level of the participants. Whereas the intense weight training regime of the strength-training students allowed them to achieve higher results in the dynamometer tests, the more multidimensional aspect of jiu-jitsu training was reflected in achieving better results in the motor tests.

Submissions to the Australian and New Zealand Review of Food Labelling Law and Policy support traffic light nutrition labelling.

Science.gov (United States)

White, John; Signal, Louise

2012-10-01

Food labels to support healthier choices are an important potential intervention for improving population health by reducing obesity and diet-related disease. This study examines the use of research evidence about traffic light nutrition labelling in submissions to the Review of Food Labelling Law and Policy conducted in Australia and New Zealand. Content analysis of final submissions to the Review and a literature review of documents reporting research evidence about traffic light labelling. Sixty-two submitters to the Review were categorised as 'supporters' of traffic light labelling and 29 as 'opponents'. Supporters focused on studies showing traffic light labels were better than other systems at helping consumers identify healthier food options. Opponents cited evidence that traffic light labels were no better than other systems in this respect and noted a lack of evidence that they led to changes in food consumption. A literature review demonstrated that, as a group, submitters had drawn attention to most of the relevant research evidence on traffic light labelling. Both supporters and opponents were, however, selective in their use of evidence. The weight of evidence suggested that traffic light labelling has strengths in helping consumers to identify healthier food options. Further research would be valuable in informing the development of an interpretive front-of-pack labelling system. The findings have significant implications for the development of front-of-pack nutrition labelling currently being considered in Australia and New Zealand. © 2012 The Authors. ANZJPH © 2012 Public Health Association of Australia.

The Relation between Degree and Strength in the Complex Network Derived from an Individual Stock

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Zelin Zhang

2016-01-01

Full Text Available A method based on coarse-graining to construct a directed weighted complex network which models the transformation of the trading data of an individual stock is introduced. The degree (strength distribution of derived network follows a power-law. A moderated regression equation with interaction effects of average return and out-degree (in-degree on out-strength (in-strength is established. Moreover, we found that the differences of nodes affect the network’s structure and average return level impacts nodes’ eigenvector centrality and pagerank, significantly.

Detection of light-matter interaction in the weak-coupling regime by quantum light

Science.gov (United States)

Bin, Qian; Lü, Xin-You; Zheng, Li-Li; Bin, Shang-Wu; Wu, Ying

2018-04-01

"Mollow spectroscopy" is a photon statistics spectroscopy, obtained by scanning the quantum light scattered from a source system. Here, we apply this technique to detect the weak light-matter interaction between the cavity and atom (or a mechanical oscillator) when the strong system dissipation is included. We find that the weak interaction can be measured with high accuracy when exciting the target cavity by quantum light scattered from the source halfway between the central peak and each side peak. This originally comes from the strong correlation of the injected quantum photons. In principle, our proposal can be applied into the normal cavity quantum electrodynamics system described by the Jaynes-Cummings model and an optomechanical system. Furthermore, it is state of the art for experiment even when the interaction strength is reduced to a very small value.

Determination of giant resonance strengths

International Nuclear Information System (INIS)

Serr, F.E.

1983-01-01

Using theoretical strength functions to describe the different giant resonances expected at excitation energies of the order of (60-85)/Asup(1/3) MeV, we calculate the double differential cross sections d 2 sigma/dΩ dE associated with the reactions 208 Pb(α, α') and 90 Zr(α, α') (Esub(α) = 152 MeV). The angular distributions for the giant quadrupole and giant monopole resonances obtained from fits to these spectra, making simple, commonly used assumptions for the peak shapes and background, are compared to the original angular distributions. The differences between them are an indication of some of the uncertainties affecting the giant resonance strengths extracted from hadron inelastic scattering data. Fits to limited angular regions lead to errors of up to 50% in the value of the energy-weighted sum rule, depending on the angles examined. While it seems possible to extract the correct EWSR for the GMR by carrying out the analyses at 0 0 , no single privileged angle seems to exist in the case of the GQR. (orig.)

Effect Of Coir Fibres On The Compaction And Unconfined Compressive Strength Of Bentonite-Lime-Gypsum Mixture

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Tilak B. Vidya

2015-06-01

Full Text Available This paper presents the effect of coir fibres on the compaction and unconfined compressive strength of a bentonite-lime-gypsum mixture. The coir fiber content varied from 0.5 to 2 %. The results indicated that the dry unit weight and the optimum moisture content of a bentonite – lime mix increased with the addition of gypsum. The unconfined compressive strength of the bentonite increased with the increase in the lime content up to 8 %. Beyond 8 %, the unconfined compressive strength decreased. The dry unit weight of the reference mix decreased, and the optimum moisture content increased with the addition of coir fibre. The unconfined compressive strength of the bentonite + 8 % lime mix increased up to 4 % with the gypsum. Beyond 4 %, the unconfined compressive strength decreased. The unconfined compressive strength of the reference mix increased with the addition of coir fibre up to a fibre content of 1.5 %. The unconfined compressive strength of the reference mix-coir fibre composite was less in comparison to the reference mix. The unconfined compressive strength of the bentonite increased with the addition of lime and gypsum and with the increase in the curing period. The improvement in the post-peak region was better for the reference mix with reinforced coir fibres as compared to the unreinforced reference mix. The improved post-peak behaviour of the bentonite-lime-gypsum-coir fibre mixture could boost the construction of temporary roads on such problematic soils. Further, its use will also provide an environmental motivation for providing a means of consuming large quantities of coir fibres.

Neural substrates of reliability-weighted visual-tactile multisensory integration

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Michael S Beauchamp

2010-06-01

Full Text Available As sensory systems deteriorate in aging or disease, the brain must relearn the appropriate weights to assign each modality during multisensory integration. Using blood-oxygen level dependent functional magnetic resonance imaging (BOLD fMRI of human subjects, we tested a model for the neural mechanisms of sensory weighting, termed “weighted connections”. This model holds that the connection weights between early and late areas vary depending on the reliability of the modality, independent of the level of early sensory cortex activity. When subjects detected viewed and felt touches to the hand, a network of brain areas was active, including visual areas in lateral occipital cortex, somatosensory areas in inferior parietal lobe, and multisensory areas in the intraparietal sulcus (IPS. In agreement with the weighted connection model, the connection weight measured with structural equation modeling between somatosensory cortex and IPS increased for somatosensory-reliable stimuli, and the connection weight between visual cortex and IPS increased for visual-reliable stimuli. This double dissociation of connection strengths was similar to the pattern of behavioral responses during incongruent multisensory stimulation, suggesting that weighted connections may be a neural mechanism for behavioral reliability weighting.for behavioral reliability weighting.

Influence of storage times on bond strength of resin cements to root canal

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Matheus Coêlho Bandéca

2010-03-01

Full Text Available The resin cements are responsible to retention of the indirect materials decreasing marginal leakage, increasing failure resistance compared with conventional cementation. The cementation within root canal is very hard due unfavorable conditions regarding the application of adhesive techniques caused by inadequate access. Therefore, considering the possibility to decrease steps of cementation, this study was performed to evaluate the bond strength of self-adhesive resin cement (RelyX TM U100, 3M ESPE and resin cement combined with self-ecthing adhesive system (Panavia® F 2.0, Kuraray light-cured with Quartz Tungsten Halogen (QTH following storage at 37 °C immediately after light-curing, 24 and 48 hours and 7 days. The root canals were prepared to receive the glass fiber post in the depth of 10 mm, irrigated with 17% EDTA and NaOCl, rinsed with distilled water and dried using paper points. The roots were perpendicularly sectioned into approximately 1 mm thick sections, obtaining ninety-six slices (n = 12. The slices were trimmed using a cylindrical diamond bur in the proximal surfaces until it touched the post and attached into a device, which were mounted on a strength tester (Bisco and loaded in tension at a speed of 0.5 mm/min until failure occurred at specimens. The analysis of variance (ANOVA and Tukey's post-hoc tests showed significant statistical differences (P .05. The resin cements 24 and 48 hours after light-curing were statistically similar among themselves (P > .05. The both resin cement showed similar bond strength into root canal on different storage times. The highest bond strength values of the resin cements were showed 7 days after curing.

Protein timing and its effects on muscular hypertrophy and strength in individuals engaged in weight-training

OpenAIRE

Stark Matthew; Lukaszuk Judith; Prawitz Aimee; Salacinski Amanda

2012-01-01

Abstract The purpose of this review was to determine whether past research provides conclusive evidence about the effects of type and timing of ingestion of specific sources of protein by those engaged in resistance weight training. Two essential, nutrition-related, tenets need to be followed by weightlifters to maximize muscle hypertrophy: the consumption of 1.2-2.0 g protein.kg -1 of body weight, and ≥44-50 kcal.kg-1 of body weight. Researchers have tested the effects of timing of protein s...

High strength alloys for high temperature service in liquid-salt cooled energy systems

Energy Technology Data Exchange (ETDEWEB)

Holcomb, David E.; Muralidharan, Govindarajan; Wilson, Dane F.

2017-01-10

An essentially cobalt-free alloy consists essentially of, in terms of weight percent: 6.3 to 7.2 Cr, 0.5 to 2 Al, 0 to 5 Fe, 0.7 to 0.8 Mn, 9 to 12.5 Mo, 0 to 6 Ta, 0.75 to 3.5 Ti, 0.01 to 0.25 Nb, 0.2 to 0.6 W, 0.02 to 0.04 C, 0 to 0.001 B, 0.0001 to 0.002 N, balance Ni. The alloy is characterized by a .gamma.' microstructural component in the range of 3 to 17.6 weight percent of the total composition. The alloy is further characterized by, at 850.degree. C., a yield strength of at least 60 Ksi, a tensile strength of at least 70 Ksi, a creep rupture life at 12 Ksi of at least 700 hours, and a corrosion rate, expressed in weight loss [g/(cm.sup.2sec)]10.sup.-11 during a 1000 hour immersion in liquid FLiNaK at 850.degree. C., in the range of 5.5 to 17.

High strength alloys for high temperature service in liquid-salt cooled energy systems

Science.gov (United States)

Holcomb, David E.; Muralidharan, Govindarajan; Wilson, Dane F.

2017-01-10

An essentially cobalt-free alloy consists essentially of, in terms of weight percent: 6.3 to 7.2 Cr, 0.5 to 2 Al, 0 to 5 Fe, 0.7 to 0.8 Mn, 9 to 12.5 Mo, 0 to 6 Ta, 0.75 to 3.5 Ti, 0.01 to 0.25 Nb, 0.2 to 0.6 W, 0.02 to 0.04 C, 0 to 0.001 B, 0.0001 to 0.002 N, balance Ni. The alloy is characterized by a .gamma.' microstructural component in the range of 3 to 17.6 weight percent of the total composition. The alloy is further characterized by, at 850.degree. C., a yield strength of at least 60 Ksi, a tensile strength of at least 70 Ksi, a creep rupture life at 12 Ksi of at least 700 hours, and a corrosion rate, expressed in weight loss [g/(cm.sup.2sec)]10.sup.-11 during a 1000 hour immersion in liquid FLiNaK at 850.degree. C., in the range of 5.5 to 17.

Effect of High-Speed Strength Training on Physical Performance in Young Soccer Players of Different Ages.

Science.gov (United States)

Rodríguez-Rosell, David; Franco-Márquez, Felipe; Mora-Custodio, Ricardo; González-Badillo, Juan José

2017-09-01

Rodríguez-Rosell, D, Franco-Márquez, F, Mora-Custodio, R, and González-Badillo, JJ. Effect of high-speed strength training on physical performance in young soccer players of different ages. J Strength Cond Res 31(9): 2498-2508, 2017-The aim of the present study was to compare the effectiveness of low-load, low-volume weight training combined with plyometrics on strength, sprint, and jump performance in soccer players of different ages. Eighty-six soccer players from the same academy were categorized into 3 groups by age (under 13 years, U13, n = 30; under 15, U15, n = 28; and under 17, U17, n = 28) and then randomly assigned into 2 subgroups: a strength training group (STG) and a control group (CG). The strength training program was performed twice a week for 6 weeks and consisted of full squats (load: 45-60% 1 repetition maximum; volume: 3 set of 8-4 repetitions), jumps, and straight line sprint exercises. After training intervention, the STGs showed significant improvements in maximal strength (7.5-54.5%; p soccer players in most variables, whereas U15 showed higher improvements in jump and strength parameters than U17 (ES: 0.25-0.90) soccer players. Thus, although our results indicates that a combined weight training and plyometrics program may be effective in eliciting gains in strength, jump, and sprint in soccer players of different ages, the training program used appears to be generally less effective as the age of the soccer players increased. Therefore, it appears that training characteristics (mainly volume, intensity, and type of exercise) should be modified in relation to maturity status and initial strength level.

Effect of dentin dehydration and composite resin polymerization mode on bond strength of two self-etch adhesives

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Pooran Samimi

2016-01-01

Full Text Available Background: Dual-cured composite resins are similar to self-cured composite resins in some of their clinical applications due to inadequate irradiation, lack of irradiation, or delayed irradiation. Therefore, incompatibility with self-etch adhesives (SEAs should be taken into account with their use. On the other, the extent of dentin dehydration has a great role in the quality of adhesion of these resin materials to dentin. The aim of this study was to investigate the effect of dentin dehydration and composite resin polymerization mode on bond strength of two SEAs. Materials and Methods: A total of 120 dentinal specimens were prepared from extracted intact third molars. Half of the samples were dehydrated in ethanol with increasing concentrations. Then Clearfil SE Bond (CSEB and Prompt L-Pop (PLP adhesives were applied in the two groups. Cylindrical composite resin specimens were cured using three polymerization modes: (1 Immediate light-curing, (2 delayed light-curing after 20 min, and (3 self-curing. Bond strength was measured using universal testing machine at a crosshead speed of 1 mm/min. Data were analyzed with two-way ANOVA and Duncan post hoc tests. Statistical significance was defined at P 0.05. PLP showed significant differences between subgroups with the lowest bond strength in hydrated dentin with delayed light-curing and self-cured mode of polymerization. Conclusion: Within the limitations of this study, a delay in composite resin light-curing or using chemically cured composite resin had a deleterious effect on dentin bond strength of single-step SEAs used in the study.

Strength Analysis of Coconut Fiber Stabilized Earth for Farm Structures

Science.gov (United States)

Enokela, O. S.; P. O, Alada

2012-07-01

Investigation of the strength characteristic of soil from alluvial deposit of River Benue in makurdi stabilized with coconut fiber as a stabilizer was carried as local building material for farm structure. Processed coconut fibers were mixed with the soil at four different mix ratios of 1% fiber, 2% fiber, 3% fiber and 4% fiber by percentage weight with 0% fiber as control. Compaction test and compressive strength were carried out on the various stabilizing ratio. From the compaction test, the correlation between the maximum dry density and optimum moisture content is a second order polynomial with a coefficient of 63% obtained at1.91kg/m3and 20.0% respectively while the compressive strength test shows an optimum failure load of 8.62N/mm2 at 2%fibre:100% soil mix ratio at 2.16 maximum dry density.

Eccentric and isometric shoulder rotator cuff strength testing using a hand-held dynamometer: reference values for overhead athletes.

Science.gov (United States)

Cools, Ann M J; Vanderstukken, Fran; Vereecken, Frédéric; Duprez, Mattias; Heyman, Karel; Goethals, Nick; Johansson, Fredrik

2016-12-01

In order to provide science-based guidelines for injury prevention or return to play, regular measurement of isometric and eccentric internal (IR) and external (ER) rotator strength is warranted in overhead athletes. However, up to date, no normative database exists regarding these values, when measured with a hand-held dynamometer. Therefore, the purpose of the study was to provide a normative database on isometric and eccentric rotator cuff (RC) strength values in a sample of overhead athletes, and to discuss gender, age and sports differences. A HHD was used to measure RC strength in 201 overhead athletes between 18 and 50 years old from three different sports disciplines: tennis, volleyball and handball. Isometric as well as eccentric strength was measured in different shoulder positions. Outcome variables of interest were isometric ER and IR strength, eccentric ER strength, and intermuscular strength ratios ER/IR. Our results show significant side, gender and sports discipline differences in the isometric and eccentric RC strength. However, when normalized to body weight, gender differences often are absent. In general, strength differences are in favour of the dominant side, the male athletes and handball. Intermuscular ER/IR ratios showed gender, sports, and side differences. This normative database is necessary to help the clinician in the evaluation of RC strength in healthy and injured overhead athletes. In view of the preventive screening and return-to-play decisions in overhead athletes, normalization to body weight and calculating intermuscular ratios are key points in this evaluation. Diagnostic study, Level III.

Fingers' vibration transmission and grip strength preservation performance of vibration reducing gloves.

Science.gov (United States)

Hamouda, K; Rakheja, S; Dewangan, K N; Marcotte, P

2018-01-01

amplification of handle vibration at the fingers. The fingers' vibration transmission performance of gloves were further evaluated using a proposed finger frequency-weighting W f apart from the standardized W h -weighting. It is shown that the W h weighting generally overestimates the VR glove effectiveness in limiting the fingers vibration in the high (H: 200-1250 Hz) frequency range. Both the weightings, however, revealed comparable performance of gloves in the mid (M: 25-200 Hz) frequency range. The VR gloves, with the exception of the leather glove, showed considerable reductions in the grip strength (27-41%), while the grip strength reduction was not correlated with the glove material thickness. It is suggested that effectiveness of VR gloves should be assessed considering the vibration transmission to both the palm and fingers of the hand together with the hand grip strength reduction. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Size and Strength Development in Elite Youth Ice Hockey Players

Directory of Open Access Journals (Sweden)

Jeff R. Leiter

2016-07-01

Full Text Available Background: Ice hockey is a fast, physical sport that requires high levels of muscular strength, muscular endurance and agility. Objectives: This study was conducted to create a profile including: anthropometric measurement, muscular strength, muscular endurance, lower body jump height and distance, and agility characteristics for elite youth hockey players.  Methods: Pre-season off-ice testing results were retrospectively reviewed from a human performance database.  Variables included height, weight, body fat percentage, grip strength, push-ups/bench press, supine rows, the plank test, vertical jump, standing long jump, hip adductor and abductor strength, and the 5-10-5 shuttle, and. One-way ANOVAs (1group x 4 time and Tukeys post-hoc tests were performed to determine changes in the immediately successive age group (p<0.05. Results: Participants included male Bantam-(age: 13-14 and Midget-(age: 15-17 AAA ice-hockey players (n=260.  Age categories were grouped as 13 years old (yo(n=75, 14 yo (n=70, 15 yo (n=58, and 16-17 yo (n=57.  Increases between successive age groups were observed in the following variables: weight (13, 14, 15 and 16-17 yo, height (13 and 14 yo, left and right grip strength (13, 14, 15, and 16-17 yo, bench press (15 and 16-17 yo, left and right hip abduction (14, 15, and 16-17 yo, and vertical and standing long jump (13, 14, and 15 yo. Total time for the 5-10-5 shuttle run test decreased from 13 to 14yo, and 14 to 15 yo. Conclusion: Changes with age in off-ice performance variables of elite amateur hockey players should be recognized, followed, and addressed during player development to maximize the potential for elite performance and reduce the risk of injury.   Keywords: Athletic Performance, Training, Physical Fitness

Development of high-strength aluminum alloys for basket in transport and storage cask for high burn-up spent fuel

International Nuclear Information System (INIS)

Maeguchi, T.; Sakaguchi, Y.; Kamiwaki, Y.; Ishii, M.; Yamamoto, T.

2004-01-01

Mitsubishi Heavy Industries, Ltd. (MHI) has developed high-strength borated aluminum alloys (high-strength B-Al alloys), suitable for application to baskets in transport and storage casks for high burn-up spent fuels. Aluminum is a suitable base material for the baskets due to its low density and high thermal conductivity. The aluminum basket would reduce weight of the cask, and effectively release heat generated by spent fuels. MHI had already developed borated aluminum alloys (high-toughness B-Al alloy), and registered them as ASME Code Case ''N-673''. However, there has been a strong demand for basket materials with higher strength in the case of MSF (Mitsubishi Spent Fuel) casks for high-burn up spent fuels, since the basket is required to stand up to higher stress at higher temperature. The high-strength basket material enables the design of a compact cask under a limitation of total size and weight. MHI has developed novel high-strength B-Al alloys which meet these requirements, based on a new manufacturing process. The outline of mechanical and metallurgical characteristics of the high-strength B-Al alloys is described in this paper

Shell cracking strength in almond (Prunus dulcis [Mill.] D.A. Webb.) and its implication in uses as a value-added product.

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Ledbetter, C A

2008-09-01

Researchers are currently developing new value-added uses for almond shells, an abundant agricultural by-product. Almond varieties are distinguished by processors as being either hard or soft shelled, but these two broad classes of almond also exhibit varietal diversity in shell morphology and physical characters. By defining more precisely the physical and chemical characteristics of almond shells from different varieties, researchers will better understand which specific shell types are best suited for specific industrial processes. Eight diverse almond accessions were evaluated in two consecutive harvest seasons for nut and kernel weight, kernel percentage and shell cracking strength. Shell bulk density was evaluated in a separate year. Harvest year by almond accession interactions were highly significant (p0.01) for each of the analyzed variables. Significant (p0.01) correlations were noted for average nut weight with kernel weight, kernel percentage and shell cracking strength. A significant (p0.01) negative correlation for shell cracking strength with kernel percentage was noted. In some cases shell cracking strength was independent of the kernel percentage which suggests that either variety compositional differences or shell morphology affect the shell cracking strength. The varietal characterization of almond shell materials will assist in determining the best value-added uses for this abundant agricultural by-product.

Epidemic spreading in weighted scale-free networks with community structure

International Nuclear Information System (INIS)

Chu, Xiangwei; Guan, Jihong; Zhang, Zhongzhi; Zhou, Shuigeng

2009-01-01

Many empirical studies reveal that the weights and community structure are ubiquitous in various natural and artificial networks. In this paper, based on the SI disease model, we investigate the epidemic spreading in weighted scale-free networks with community structure. Two exponents, α and β, are introduced to weight the internal edges and external edges, respectively; and a tunable probability parameter q is also introduced to adjust the strength of community structure. We find the external weighting exponent β plays a much more important role in slackening the epidemic spreading and reducing the danger brought by the epidemic than the internal weighting exponent α. Moreover, a novel result we find is that the strong community structure is no longer helpful for slackening the danger brought by the epidemic in the weighted cases. In addition, we show the hierarchical dynamics of the epidemic spreading in the weighted scale-free networks with communities which is also displayed in the famous BA scale-free networks

RELIABILITY OF ANKLE-FOOT MORPHOLOGY, MOBILITY, STRENGTH, AND MOTOR PERFORMANCE MEASURES.

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Fraser, John J; Koldenhoven, Rachel M; Saliba, Susan A; Hertel, Jay

2017-12-01

Assessment of foot posture, morphology, intersegmental mobility, strength and motor control of the ankle-foot complex are commonly used clinically, but measurement properties of many assessments are unclear. To determine test-retest and inter-rater reliability, standard error of measurement, and minimal detectable change of morphology, joint excursion and play, strength, and motor control of the ankle-foot complex. Reliability study. 24 healthy, recreationally-active young adults without history of ankle-foot injury were assessed by two clinicians on two occasions, three to ten days apart. Measurement properties were assessed for foot morphology (foot posture index, total and truncated length, width, arch height), joint excursion (weight-bearing dorsiflexion, rearfoot and hallux goniometry, forefoot inclinometry, 1 st metatarsal displacement) and joint play, strength (handheld dynamometry), and motor control rating during intrinsic foot muscle (IFM) exercises. Clinician order was randomized using a Latin Square. The clinicians performed independent examinations and did not confer on the findings for the duration of the study. Test-retest and inter-tester reliability and agreement was assessed using intraclass correlation coefficients (ICC 2,k ) and weighted kappa ( K w ). Test-retest reliability ICC were as follows: morphology: .80-1.00, joint excursion: .58-.97, joint play: -.67-.84, strength: .67-.92, IFM motor rating: K W -.01-.71. Inter-rater reliability ICC were as follows: morphology: .81-1.00, joint excursion: .32-.97, joint play: -1.06-1.00, strength: .53-.90, and IFM motor rating: K w .02-.56. Measures of ankle-foot posture, morphology, joint excursion, and strength demonstrated fair to excellent test-retest and inter-rater reliability. Test-retest reliability for rating of perceived difficulty and motor performance was good to excellent for short-foot, toe-spread-out, and hallux exercises and poor to fair for lesser toe extension. Joint play measures had

Green LED as an Effective Light Source for Curing Acrylate-Based Dental Resins in Combination with Irgacure 784

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Katalin Bukovinszky

2018-01-01

Full Text Available Low intensity green light emitting diodes (LED were shown to be an effective light source to induce the photopolymerization of an acrylate-based photocurable dental restorative resin mixture of bisphenol A glycerolate dimethacrylate (BisGMA, triethylene glycol dimethacrylate (TEGDMA, and diurethane dimethacrylate (UDMA, in combination with fluorinated diaryl titanocene (Irgacure 784. Dental matrices were prepared by the LED light source at different intensities. The mechanical properties, such as Vickers microhardness, compressive strength, diametric tensile strength, flexural strength, and E-modulus of the created samples, were investigated. The kinetics of the photopolymerization was followed by Raman spectroscopy and conversion values were determined. It was found that, despite its narrow-emission range centered at a wavelength of 531 nm, the green LED light source is suitable for the preparation of dental matrices with good mechanical properties and high conversion values.

The influence of humidity on strengths and durability of light guides fibers

International Nuclear Information System (INIS)

Karimov, S.N.; Kuksenko, V.S.; Sultonov, U.; Abdumanonov, A.; Shamsidinov, M.I.

1993-01-01

Humidity influence on durability and light water durability fibres is studied are studied in this article. Humidity energy under influence of process destruction decreases activity, durability and durability decreases is shown

SHEAR STRENGTH IN THE GLUE LINE OF Eucalyptus sp. AND Pinus sp.WOOD

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Juliana Jerásio Bianche

Full Text Available ABSTRACT To evaluate the adhesive efficiency on the union of glued joints in a particular temperature and humidity conditions for a specified time the adhesive must be submitted to specific load tests, such as shear in the glue line. The objective of this study was to evaluate the shear strength in the glue line of Eucalyptus sp and Pinus sp.woods. Five adhesives (castor oil, sodium silicate, modified silicate, , PVA and resorcinol-formaldehyde, three weights (150 g/m2, 200 g/m2, and 250 g/m2 and two species (Eucalyptus sp. and Pinus sp. of wood were used. Twelve specimens were obtained from each repetition per treatment, corresponding to 108 specimens that were conditioned at a temperature of 23 ± 1°C and relative humidity of 50 ± 2%. The interaction between the weight and type of adhesive was significant for the shear strength in the glue line of eucalyptus wood. However, no interaction between the weight and the adhesive was found for pinus, only the isolated from the adhesive effect. Chemical bonds originated in the polymerization of resorcinol-formaldehyde adhesives and castor bi-component conferred upon these adhesives the greatest resistance in the glue line. Castor and resorcinol-formaldehyde adhesives showed the highest shear strength values in the line of glue and wood failure. Castor adhesive presented satisfactory performance for bonding of eucalyptus and pine woods.

An Incremental Weighted Least Squares Approach to Surface Lights Fields

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Coombe, Greg; Lastra, Anselmo

An Image-Based Rendering (IBR) approach to appearance modelling enables the capture of a wide variety of real physical surfaces with complex reflectance behaviour. The challenges with this approach are handling the large amount of data, rendering the data efficiently, and previewing the model as it is being constructed. In this paper, we introduce the Incremental Weighted Least Squares approach to the representation and rendering of spatially and directionally varying illumination. Each surface patch consists of a set of Weighted Least Squares (WLS) node centers, which are low-degree polynomial representations of the anisotropic exitant radiance. During rendering, the representations are combined in a non-linear fashion to generate a full reconstruction of the exitant radiance. The rendering algorithm is fast, efficient, and implemented entirely on the GPU. The construction algorithm is incremental, which means that images are processed as they arrive instead of in the traditional batch fashion. This human-in-the-loop process enables the user to preview the model as it is being constructed and to adapt to over-sampling and under-sampling of the surface appearance.

Relationship between isometric thigh muscle strength and minimum clinically important differences in knee function in osteoarthritis: data from the osteoarthritis initiative.

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Ruhdorfer, Anja; Wirth, Wolfgang; Eckstein, Felix

2015-04-01

To determine the relationship between thigh muscle strength and clinically relevant differences in self-assessed lower leg function. Isometric knee extensor and flexor strength of 4,553 Osteoarthritis Initiative participants (2,651 women and 1,902 men) was related to the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) physical function scores by linear regression. Further, groups of male and female participant strata with minimum clinically important differences (MCIDs) in WOMAC function scores (6 of 68 units) were compared across the full range of observed values and to participants without functional deficits (WOMAC score 0). The effect of WOMAC knee pain and body mass index on the above relationships was explored using stepwise regression. Per regression equations, a 3.7% reduction in extensor strength and a 4.0% reduction in flexor strength were associated with an MCID in WOMAC function in women, and, respectively, a 3.6% and 4.8% reduction in men. For strength divided by body weight, reductions were 5.2% and 6.7%, respectively, in women and 5.8% and 6.7%, respectively, in men. Comparing MCID strata across the full observed range of WOMAC function confirmed the above estimates and did not suggest nonlinear relationships across the spectrum of observed values. WOMAC pain correlated strongly with WOMAC function, but extensor (and flexor) muscle strength contributed significant independent information. Reductions of approximately 4% in isometric muscle strength and of 6% in strength per body weight were related to a clinically relevant difference in WOMAC functional disability. Longitudinal studies will need to confirm these relationships within persons. Muscle extensor (and flexor) strength (per body weight) provided significant independent information in addition to pain in explaining variability in lower leg function. Copyright © 2015 by the American College of Rheumatology.

Fundamental corrosion characterization of high-strength titanium alloys

International Nuclear Information System (INIS)

Schutz, R.W.; Grauman, J.S.

1984-01-01

Many commercially available and several developmental high-strength titanium alloys were evaluated for application in chloride-containing environments with respect to general, crevice, and stress corrosion resistance. Studies in boiling reducing and oxidizing acid chloride media permitted identification of certain high-strength titanium alloys, containing ≥4 weight % molybdenum, which are significantly more resistant than unalloyed titanium with respect to general and crevice attack. Data regression analysis suggests that molybdenum and vanadium impart a significant positive effect on alloy corrosion resistance under reducing acid chloride conditions, whereas aluminum is detrimental. Little effect of metallurgical condition (that is, annealed versus aged) on corrosion behavior of the higher molybdenum-containing alloys was noted. No obvious susceptibility to chloride and sulfide stress corrosion cracking (SCC) was detected utilizing U-bend specimens at 177 0 C

Effects of hyperthyroidism on hand grip strength and function.

Science.gov (United States)

Erkol İnal, Esra; Çarlı, Alparslan Bayram; Çanak, Sultan; Aksu, Oğuzhan; Köroğlu, Banu Kale; Savaş, Serpil

2015-01-01

Hyperthyroidism is a pathologic condition in which the body is exposed to excessive amounts of circulating thyroid hormones. Skeletal muscle is one of the major target organs of thyroid hormones. We evaluated hand grip strength and function in patients with overt hyperthyroidism. Fifty-one patients newly diagnosed with hyperthyroidism and 44 healthy controls participated in this study. Age, height, weight, and dominant hand of all participants were recorded. The diagnosis of hyperthyroidism was confirmed by clinical examination and laboratory tests. Hand grip strength was tested at the dominant hand with a Jamar hand dynamometer. The grooved pegboard test (PGT) was used to evaluate hand dexterity. The Duruöz Hand Index (DHI) was used to assess hand function. No significant differences were found in terms of clinical and demographic findings between the patients with hyperthyroidism and healthy controls (p > 0.05). Significant differences were found between the patients with hyperthyroidism and healthy controls regarding PGT and DHI scores (p Hyperthyroidism seemed to affect hand dexterity and function more than hand grip strength and seemed to be associated with reduced physical function more than muscle strength. This may also indicate that patients with hyperthyroidism should be evaluated by multidisplinary modalities.

Does light attract piglets to the creep area?

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Larsen, M L V; Pedersen, L J

2015-06-01

Hypothermia, experienced by piglets, has been related to piglet deaths and high and early use of a heated creep area is considered important to prevent hypothermia. The aims of the present study were to investigate how a newly invented radiant heat source, eHeat, would affect piglets' use of the creep area and whether light in the creep area works as an attractant on piglets. A total of 39 sows, divided between two batches, were randomly distributed to three heat source treatments: (1) standard infrared heat lamp (CONT, n=19), (2) eHeat with light (EL, n=10) and (3) eHeat without light (ENL, n=10). Recordings of piglets' use of the creep area were made as scan sampling every 10 min for 3 h during two periods, one in daylight (0900 to 1200 h) and one in darkness (2100 to 2400 h), on day 1, 2, 3, 7, 14 and 21 postpartum. On the same days, piglets were weighted. Results showed an interaction between treatment and observation period (Pcreep area during darkness compared with daylight for CONT and EL litters, but not for ENL litters. Piglets average daily weight gain was not affected by treatment, but was positively correlated with piglets' birth weight and was lower in batch 1 compared with batch 2. Seen from the present results, neither eHeat nor light worked as an attractant on piglets; in contrast, piglets preferred to sleep in the dark and it would therefore be recommended to turn off the light in the creep area during darkness. Heating up the creep area without light can be accomplished by using a radiant heat source such as eHeat in contrast to the normally used light-emitting infrared heat lamp.

Distinct contributions of explicit and implicit memory processes to weight prediction when lifting objects and judging their weights: an aging study.

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Trewartha, Kevin M; Flanagan, J Randall

2016-09-01

Weight predictions used to scale lifting forces adapt quickly when repeatedly lifting unusually weighted objects and are readily updated by explicit information provided about weight. In contrast, weight predictions used when making perceptual judgments about weight are more resistant to change and are largely unaffected by explicit information about weight. These observations suggest that distinct memory systems underlie weight prediction when lifting objects and judging their weights. Here we examined whether these weight predictions differ in their reliance on declarative and nondeclarative memory resources by comparing the adaptability of these predictions in older adults, who exhibit relatively impaired declarative memory processes, to those in younger adults. In the size condition, we measured lift forces as participants repeatedly lifted a pair of size-weight inverted objects in alternation. To assess weight judgments, we measured the size-weight illusion every 10 lifts. The material condition was similar, except that we used material-weight inverted objects and measured the material-weight illusion. The strengths of these illusions prior to lifting, and the attenuation of the illusions that arise when lifting inverted objects, were similar for both groups. The magnitude of the change in the illusions was positively correlated with implicit memory performance in both groups, suggesting that predictions used when judging weight rely on nondeclarative memory resources. Updating of lifting forces also did not differ between groups. However, within the older group the success with which lifting forces were updated was positively correlated with working memory performance, suggesting that weight predictions used when lifting rely on declarative memory resources. Copyright © 2016 the American Physiological Society.

Strength Performance of Blended Ash Based Geopolymer Mortar

Science.gov (United States)

Zahib, Zaidahtulakmal M.; Kamaruddin, Kartini; Saman, Hamidah M.

2018-03-01

Geopolymer is a based on inorganic alumino-silicate binder system. Geopolymeric materials are formed using materials that containing silica and aluminium such as fly ash and rice husk ash, which activated by alkaline solution. This paper presents the study on the effect of replacement of SSA in RHA based geopolymer, types of curing and different molarity of NaOH used on the strength of Sewage Sludge Ash (SSA) and Rice Husk Ash (RHA) based geopolymer mortar incorporating with three (3) different mix proportions. Based geopolymer mortar was synthesized from treated sewage sludge and rice husk undergoing incineration process in producing ashes, activated with sodium silicate and sodium hydroxide solution by ratio of 2.5:1 and solution to ash ratio of 1:1. Molarity of 8M and 10M NaOH were used. The percentages of SSA replacement were 0%, 10% and 20% by weight. Compressive strength was conducted at age 7, 14 and 28 days to see the development of strength with two curing regimes, which are air curing and oven curing (60°C for 24 hours). From the research conducted, the ultimate compressive strength (6.28MPa) was obtained at zero replacement of SSA taken at 28 days of oven curing with 10M of NaOH. This shows that RHA, which is rich in silica content is enough to enhance the strength of geopolymer mortar especially with high molarity of NaOH.

The effect of different light-curing units on fatigue behavior and degree of conversion of a resin composite.

Science.gov (United States)

Lohbauer, Ulrich; Rahiotis, Christos; Krämer, Norbert; Petschelt, Anselm; Eliades, George

2005-07-01

The aim of this study was to investigate the effect of different light-curing units and irradiation modes on the mechanical fatigue strength and degree of conversion of a restorative resin composite. Conventional halogen, plasma arc and blue LED light-curing units were used for polymerization of a resin composite (Tetric) Ceram, Ivoclar, Vivadent, Liechtenstein). Initial fracture strength (FS) and flexural fatigue limit (FFL) as well as degree of conversion (DC) were measured. The FFL was determined under cyclic loading for 10(5) cycles in terms of a staircase approach. The specimens were stored for 14 days in 37 degrees C distilled water prior to testing. The curing efficiency was observed with Fourier transform infrared micromultiple internal reflectance spectroscopy. The measurements were carried out at 0.5 and 2.5 mm distance from the directly irradiated surface after 14 days storage in dark and dry conditions at 37 degrees C. The highest FS, FFL and DC were observed from high energy curing devices and from extended curing intervals. The conventional halogen light exhibited the most homogenous in-depth curing efficiency along with a low loss of mechanical resistance under cyclic fatigue. Evaluation of flexural fatigue limit and curing efficiency correlate in terms of decreased mechanical strength due to insufficient light-curing intervals or light intensities. Initial promising fracture strengths do not correlate with a clinically more relevant fatigue loading and with the in-depth degree of conversion, both accounting for a significantly reduced strength performance.

Experimentally simulating the dynamics of quantum light and matter at ultrastrong coupling using circuit QED (2) - light dynamics and light-matter entanglement -

Science.gov (United States)

Sagastizabal, R.; Langford, N. K.; Kounalakis, M.; Dickel, C.; Bruno, A.; Luthi, F.; Thoen, D. J.; Endo, A.; Dicarlo, L.

Light-matter interaction can lead to large photon build-up and hybrid atom-photon entanglement in the ultrastrong coupling (USC) regime, where the coupling strength becomes comparable to the eigenenergies of the system. Accessing the cavity degree of freedom, however, is an outstanding challenge in natural USC systems. In this talk, we directly probe light field dynamics in the USC regime using a digital simulation of the quantum Rabi model in a planar circuit QED chip with a transmon moderately coupled to a resonator. We produce high-accuracy USC light-matter dynamics, using second-order Trotterisation and up to 90 Trotter steps. We probe the average photon number, photon parity and perform Wigner tomography of the simulated field. Finally, we combine tomography of the resonator with qubit measurements to evidence the Schrödinger-cat-like atom-photon entanglement which is a key signature of light-matter dynamics in the USC regime. Funding from the EU FP7 Project ScaleQIT, the ERC Synergy Grant QC-lab, the Netherlands Organization of Scientic Research (NWO), and Microsoft Research.

Gender Differences in Isokinetic Strength after 60 and 90 d Bed Rest

Science.gov (United States)

English, K. L.; Ploutz-Snyder, R. J.; Cromwell, R. L.; Ploutz-Snyder, L. L.

2010-01-01

Recent reports suggest that changes in muscle strength following disuse may differ between males and females. PURPOSE: To examine potential gender differences in strength changes following 60 and 90 d of experimental bed rest. METHODS: Isokinetic extensor and flexor strength of the knee (60deg and 180deg/s, concentric only), ankle (30deg/s, concentric and eccentric), and trunk (60deg/s, concentric only) were measured following 60 d (males: n=4, 34.5+/-9.6 y; females: n=4, 35.5+/-8.2 y) and 90 d (males: n=10, 31.4+/-4.8 y; females: n=5, 37.6+/-9.9 y) of 6-degree head-down-tilt bed rest (BR; N=23). Subjects were fed a controlled diet (55%/15%/ 30%, CHO/PRO/FAT) that maintained body weight within 3% of the weight recorded on Day 3 of bed rest. After a familiarization session, testing was conducted 6 d before BR and 2 d after BR completion. Peak torque and total work were calculated for the tests performed. To allow us to combine data from both 60- and 90-d subjects, we used a mixed-model statistical analysis in which time and gender were fixed effects and bed rest duration was a random effect. Log-transformations of strength measures were utilized when necessary in order to meet statistical assumptions. RESULTS: Main effects were seen for both time and gender (p<0.05), showing decreased strength in response to bed rest for both males and females, and males stronger than females for most strength measures. Only one interaction effect was observed: females exhibited a greater loss of trunk extensor peak torque at 60 d versus pre-BR, relative to males (p=0.004). CONCLUSION: Sixty and 90 d of BR induced significant losses in isokinetic muscle strength of the locomotor and postural muscles of the knee, ankle, and trunk. Although males were stronger than females for most of the strength measures that we examined, only changes in trunk extensor peak torque were greater for females than males at day 60 of bed rest

Engineering and economics of lighting for closed circuit television (CCTV) security alarm assessment

International Nuclear Information System (INIS)

Faucett, R.E.; Schow, F.L.

1979-01-01

The study examines the economics and applicability of low and high pressure sodium sources in both streetlight and floodlight luminaires for CCTV illumination of high-security areas. In addition the signal outputs of several popular CCTV camera tube types operated in the presence of common lighting sources are calculated. These calculations take into consideration the spectral response of the camera tubes and the spectral output of the light sources. The results are presented in terms of dollars per unit camera signal strength and also camera signal strength per connected watt of electrical load

Strength and cardiometabolic risk in young adults: The mediator role of aerobic fitness and waist circumference.

Science.gov (United States)

Díez-Fernández, A; Martínez-Vizcaíno, V; Torres-Costoso, A; Cañete García-Prieto, J; Franquelo-Morales, P; Sánchez-López, M

2018-02-22

The aim of this study was to analyze the mediation role of cardiorespiratory fitness and waist circumference in the association between muscular strength and cardiometabolic risk. A cross-sectional study involved first-year college students (n = 370) from a Spanish public university was performed. We measured weight, height, waist circumference, blood pressure, biochemical variables, maximum handgrip strength assessment, and cardiorespiratory fitness. We calculated handgrip dynamometry/weight and a previously validated cardiometabolic risk index. Analysis of covariance models was conducted to test differences in cardiometabolic risk values across muscular strength, cardiorespiratory fitness, and waist circumference categories, controlling for confounders. Hayes' PROCESS macro was used for the multiple mediation analysis. The relationship between muscular strength and cardiometabolic risk did not remain significant (c' = 1.76 [1.4]; P > .05) in a multiple serial bootstrapped mediation model including cardiorespiratory fitness and waist circumference as mediators when controlling for age and sex. According to the indirect effect, the significant paths in the model mediating this relationship between muscular strength and cardiometabolic risk index were as follows: muscular strength → waist circumference → cardiometabolic risk index (-4.899; 95% CI: -6.690; -3.450) and muscular strength → cardiorespiratory fitness → waist circumference → cardiometabolic risk index (-0.720; 95% CI: -1.316; -0.360). Both cardiorespiratory fitness and waist circumference mediate the association between muscular strength and cardiometabolic risk in young adults. Thus, our results place cardiorespiratory fitness and waist circumference as the main targets of physical activity programmes aimed at preventing cardiometabolic diseases. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Strength testing and training of rowers: a review.

Science.gov (United States)

Lawton, Trent W; Cronin, John B; McGuigan, Michael R

2011-05-01

performance during the competition phase. Additionally, specific on-water strength training practices such as towing ropes had not been reported. Further research should examine the on-water benefits associated with various strength training protocols, in the context of the training phase, weight division, experience and level of rower, if limitations to the reliability and precision of performance data (e.g. 2000-m time or rank) can be controlled. In conclusion, while positive ergometer time-trial benefits of clinical and practical significance were reported with strength training, a lack of statistical significance was noted, primarily due to an absence of quality long-term controlled experimental research designs.

Effect of Hand Mixing on the Compressive Strength of Concrete

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James Isiwu AGUWA

2010-12-01

Full Text Available This paper presents the effect of hand mixing on the compressive strength of concrete. Before designing the concrete mix, sieve analysis of sharp sand and chippings was carried out and their fineness moduli were determined. Also the dry weight of chippings and the specific gravities of both sand and chippings were determined. A designed concrete mix of 1:2:4 was used and the number of turnings of the mixture over from one end to another by hand mixing was varying from one time up to and including seven times. The strengths were measured at the curing ages of 7, 14, 21 and 28 days respectively using 150mm concrete cubes cast, cured and crushed. The results revealed that the compressive strengths of concrete cubes appreciably increased with increase in number of turnings from one to four times but remained almost constant beyond four times of turning for all the ages tested. For example, at 1, 2, and 3 times turning; the compressive strengths at 28 days were 4.67, 13.37 and 20.28N/mm2 respectively while at 4, 5 and 6 times turning; the compressive strengths at 28 days were 21.15, 21.34 and 21.69N/mm2. From the data, adequate strengths were not developed at turnings below three times of hand mixing, concluding that a minimum of three times turning is required to produce concrete with satisfactory strength.

Strength analysis and optimization of writing mechanism of steel billet marking machine

Directory of Open Access Journals (Sweden)

Fu Min

2017-01-01

Full Text Available According to steel billet marking theory of plasma arc nicking, the paper designs a dual laser ranging marking machine against online marking of special steel billet and realizes multi-character marking of the end face of hot steel billet. Writing mechanism bases on the rectangular coordinates marking form, Z axis adopts cantilever structure. It completes the overall marking task utilizing the synergy of KK module in X axis, Y axis and Z axis. It makes modal analysis on the writing mechanism model established by Pro/Enginner utilizing ANSYS Workbench at the position of X1Y1Z1, and obtains the first six order modal frequency and analyzes the vibration in the writing process. Moreover, the paper analyzes the static structure of the cantilever of writing mechanism, computes its maximum stress and total deformation. To make the writing mechanism reach the target of light weight, the paper optimizes Z-axis cantilever of writing mechanism. According to the analysis, it is known that the optimized Z-axis cantilever of the writing mechanism still meets the strength and rigidity requirement and total mass declines approximately 30%.

Effect of provisional cements on shear bond strength of porcelain laminate veneers.

Science.gov (United States)

Altintas, Subutay Han; Tak, Onjen; Secilmis, Asli; Usumez, Aslihan

2011-08-01

The purpose of this study was to evaluate the effect of three provisional cements and two cleaning techniques on the final bond strength of porcelain laminate veneers. The occlusal third of the crowns of forty molar teeth were sectioned and embedded in autopolymerizing acrylic resin. Dentin surfaces were polished and specimens were randomly divided into four groups (n=10). Provisional restorations were fabricated and two provisional restorations were cemented onto each tooth. Restorations were fixed with one of three different provisional cements: eugenol-free provisional cement (Cavex), calcium hydroxide (Dycal), and light-cured provisional cement (Tempond Clear). Provisional restorations were removed with either a dental explorer and air-water spray, or a cleaning bur (Opticlean). In the control group, provisional restorations were not used on the surfaces of specimens. IPS Empress 2 ceramic discs were luted with a dual-cured resin cement (Panavia F). Shear bond strength was measured using a universal testing machine. Data were statistically analyzed by ANOVA, Tukey's HSD and Dunnett tests. Surfaces were examined by scanning electronic microscopy. Significant differences were found between the control group and both the light-cured provisional cement groups and the eugenol-free provisional cement-cleaning bur group (Pprovisional cement showed the lowest bond strength values. Selection of the provisional cement is an important factor in the ultimate bond strength of the final restoration. Calcium hydroxide provisional cement and cleaning with a dental explorer are advisable.

Drop weight impact strength measurement method for porous concrete using laser doppler velocimetry

NARCIS (Netherlands)

Agar-Ozbek, A.S.; Weerheijm, J.; Schlangen, E.; Breugel, K. van

2012-01-01

In this study, an experimental configuration that reveals the dynamic response of porous concretes in a drop weight impact test was introduced. Through the measurement of particle velocity at the interface, between the impactor and the concrete target, the dynamic response was obtained in an easily

In vitro comparative study of share bond of light cured composite resins with halogen light and argon laser, using stainless steel brackets on human premolars

International Nuclear Information System (INIS)

Carillo, Vitoria Eugenia Bismarck

2004-01-01

The aim of this study in vitro was to compare the share bond strength of the light-cured composite resins Transbond XT (Unitek), with halogen light and argon laser. The Adhesive Remmant Index (ARI) was also investigated. The brackets Dyna lock (3M-UNITEK) were bonded to 75 human premolars, divided into 5 groups (15 each) according to time and the polymerization: Group H20, 15 brackets bonded with halogen light for 20s (10s both sides); Group H40, 15 brackets bonded with halogen light for 40s (20s both sides); Group A40, 15 brackets bonded with argon laser for 40s (20s both sides); Group A20, 15 brackets bonded with argon laser for 20s (10s both sides); Group A10, 15 brackets bonded with argon laser for 10s (5s both sides). The pulpal temperature changes were determined during a polymerization, not exceeding 3,5 deg C. After bonding, the teeth were submitted to a thermo cycled of 700 cycles between 5 deg C and 55 deg C, to simulate the consuming that the light cured composite resin would have in a short space of time. The specimens were then placed in PVC ring and embedded in acrylic resin (Aero-Jet). The tensile bond strength test was performed on an Universal Machine set at a crosshead speed of 1,5 mm/min, and for each rupture we registered a graphic and the best load required in Newtons, was converted to MPa and kgf. The share bond strength showed bigger values for the exposure time of 20 seconds, for the Group bonded for halogen light (H20), 7,45 kgf (7,64 MPa) and for argon laser 7,50 kgf (7,69 MPa); lesser values for the exposure time of 40s for the Group with halogen light (H40), 6,15 kgf (6,30 MPa) and argon laser Group (A40), 6,20 kgf (6,35 MPa) 0; and A10, 4,85 kgf (4,97 MPa). In the ARI Index, only A40 Group showed the 1 Index, with statistical results. In this Group, less than half of the remainder adhesive stayed on the surface of the enamel, conferring specimens failed at the enamel-adhesive interface. The results of the in vitro study demonstrate that

Workability and Compressive Strength for Concrete With Coconut Shell Aggregate

Directory of Open Access Journals (Sweden)

Leman Alif Syazani

2017-01-01

Full Text Available This study was conducted to investigate the compressive strength and workability of concrete added with coconut shells. Comparisons were made between conventional concrete with concrete mix coconut shell. In this study, the concretes were mixes with coconut shell by percentage of weight concrete which is 0%, 5%, and 10%. The coconut shell has been crushed first, then it was sieved, to get the optimum size which, that retained on the 5mm sieve and passing 10mm sieve. Experimental tests conducted in this study are slump test and compressive test. The results from this study are workability of concrete added with 0% and 5% of coconut shell has medium degree of workability compared to concrete added with 10% that has low workability. For the compressive strength, the concrete added with 5% and 10% of coconut shell has lower strength compared with normal concrete.

On the total irregularity strength of caterpillar with each internal vertex has degree three

Science.gov (United States)

Indriati, Diari; Rosyida, Isnaini; Widodo

2018-04-01

Let G be a simple, connected and undirected graph with vertex set V and edge set E. A total k-labeling f:V \\cup E\\to \\{1,2,\\ldots,k\\} is defined as totally irregular total k-labeling if the weights of any two different both vertices and edges are distinct. The weight of vertex x is defined as wt(x)=f(x)+{\\sum }xy\\in Ef(xy), while the weight of edge xy is wt(xy)=f(x)+f(xy)+f(y). A minimum k for which G has totally irregular total k-labeling is mentioned as total irregularity strength of G and denoted by ts(G). This paper contains investigation of totally irregular total k-labeling and determination of their total irregularity strengths for caterpillar graphs with each internal vertex between two stars has degree three. The results are ts({S}n,3,n)=\\lceil \\frac{2n}{2}\\rceil, ts({S}n,3,3,n)=\\lceil \\frac{2n+1}{2}\\rceil and ts({S}n,3,3,3,n)=\\lceil \\frac{2n+2}{2}\\rceil for n > 4:

Dim Light at Night Disrupts Molecular Circadian Rhythms and Affects Metabolism

Science.gov (United States)

Fonken, Laura K.; Aubrecht, Taryn G.; Meléndez-Fernández, O. Hecmarie; Weil, Zachary M.; Nelson, Randy J.

2014-01-01

With the exception of high latitudes, life has evolved under bright days and dark nights. Most organisms have developed endogenously driven circadian rhythms which are synchronized to this daily light/dark cycle. In recent years, humans have shifted away from the naturally occurring solar light cycle in favor of artificial and sometimes irregular light schedules produced by electrical lighting. Exposure to unnatural light cycles is increasingly associated with obesity and metabolic syndrome; however the means by which environmental lighting alters metabolism are poorly understood. Thus, we exposed mice to nighttime light and investigated changes in the circadian system and body weight. Here we report that exposure to ecologically relevant levels of dim (5 lux) light at night attenuate core circadian clock rhythms in the SCN at both the gene and protein level. Moreover, circadian clock rhythms were perturbed in the liver by nighttime light exposure. Changes in the circadian clock were associated with temporal alterations in feeding behavior and increased weight gain. These results are significant because they provide mechanistic evidence for how mild changes in environmental lighting can alter circadian and metabolic function. PMID:23929553

Reducing Weight for Transportation Applications: Technology Challenges and Opportunities

Science.gov (United States)

Taub, Alan I.

Today's land, sea and air transportation industries — as a business necessity — are focused on technology solutions that will make vehicles more sustainable in terms of energy, the environment, safety and affordability. Reducing vehicle weight is a key enabler for meeting these challenges as well as increasing payload and improving performance. The potential weight reductions from substituting lightweight metals (advanced high-strength steels, aluminum, magnesium and titanium alloys) are well established. For magnesium castings, weight savings of 60% have been reported [1]. The value of weight reduction depends on the transportation sector and ranges from about 5/kg saved for automobiles to over 500/kg saved for aircraft [2]. The challenge is to optimize the material properties and develop robust, high volume, manufacturing technologies and the associated supply chain to fabricate components and subsystems at the appropriate cost for each application.

Vector mesons on the light front

International Nuclear Information System (INIS)

Naito, K.; Maedan, S.; Itakura, K.

2004-01-01

We apply the light-front quantization to the Nambu-Jona-Lasinio model with the vector interaction, and compute vector meson's mass and light-cone wavefunction in the large N limit. Following the same procedure as in the previous analyses for scalar and pseudo-scalar mesons, we derive the bound-state equations of a qq-bar system in the vector channel. We include the lowest order effects of the vector interaction. The resulting transverse and longitudinal components of the bound-state equation look different from each other. But eventually after imposing an appropriate cutoff, one finds these two are identical, giving the same mass and the same (spin-independent) light-cone wavefunction. Mass of the vector meson decreases as one increases the strength of the vector interaction

Concentration of E2 strength near the fission barrier of 232Th

International Nuclear Information System (INIS)

Arruda Neto, J.D.T.; Vannucci, M.F.B.M.; Herdade, S.B.; Vannucci, A.; Nascimento, I.C. do.

1981-08-01

The electrofission angular distribution of 232 Th, in the energy interval 5.5-7 MeV, was measured. The analysis of substantial amount of E2 fission strength is concentrated near the fission barrier, corresponding to (8 +- 2)% of one energy weighted sum rule unity. (Author) [pt

Cryogenic explosion environment modeling and testing of space shuttle and light-weight radioisotope heater unit interactions