Dynamic Range of Motion Exercises

A woman is stretching her arms upward. Photo Credit Maria Teijeiro/DigitalVision/Getty Images

Overview

Doing dynamic range of motion exercises, or dynamic stretching, before physical activity, helps warm up your muscles while increasing the blood and oxygen flow throughout your body. Dynamic range of motion exercises stretch your muscles while emphasizing force and speed. Rather than holding a static, or stationary, stretch, they take your muscles through constant movement and contribute to increases in range of motion that may improve athletic performance, reduce muscular stiffness and improve joint mobility.

Knee to Chest Run

The “knee to chest run” warms up your legs, glutes and hip flexors, while challenging them through their range of motion. Stand up straight and position your feet shoulder-width apart. Bend your arms and tuck your elbows by your sides. Jog in place for 30 seconds to warm up your legs, then begin the range of motion exercise. Running in place, alternate lifting your knees toward your chest, as high as possible. Land gently on the balls of your feet and continue for 45 seconds. Maintain a straight back and squared shoulders during drill.

Straight Leg March

The "straight leg march" improves range of motion in your glutes and your hamstrings, located on the back of your thighs. Warming them up before exercise may make it easier to run or perform other lower-body activities. Stand up straight, and position your feet shoulder-width apart. Contract your abdominal muscles and lift your arms to your sides, parallel to the floor. Lift your right leg off the ground, flex your toes upward and kick in front of you. If possible, lift your leg parallel to the floor. Simultaneously, reach your left hand toward your toes. Return both to the start position and do the same with your left leg and right hand. Continue alternating until you complete your desired amount of marches. When you master the form and coordination, increase your speed.

Lying Scorpion

The “lying scorpion” stretches and improves range of motion in your shoulders, quadriceps, abdominal muscles and hip flexors. Lie face-down on a mat, resting your arms on the ground, hands by your hips, palms facing down. Keeping your chest and upper body on the floor, pick your right leg off the ground and cross it as far as possible over your left leg. Return to the start position and do the same with your left leg. Continue this pattern until you complete your desired amount of lifts. Crossing your leg as far as possible while maintaining form, helps you increase your lower body and abdominal range of motion.

Arm Swings

Dynamic arm swings stretch your chest, upper back and shoulder muscles while challenging their range of motion. Standing up straight, lift your arms to your sides. Swing them in front of your body and cross them. Immediately, swing your arms behind your back, as far as possible. Keep your arms straight throughout this dynamic exercise. Continue this pattern until you complete your desired amount of swings.

www.livestrong.com

Improvement in thermal, mechanical and water resistance properties of epoxy/glass particulate composites

Published Date

December 2010, Volume 14, Issue 2, pp 167-178

First online: 14 April 2011

Title 

Improvement in thermal, mechanical and water resistance properties of epoxy/glass particulate composites

• Author 

• H. C. Joshi
• , A. N. Tiwari 
• , R. K. Goyal

Abstract

Glass particulate reinforced epoxy matrix composites containing 0 to 32 vol% glass particulate were prepared by mechanical mixing followed by hot pressing. For this, lead borosilicate glass of composition 75PbO, 7B2O3, 14SiO2, 3Al2O3, and 1P2O3 (by wt%) was prepared by melting the requisite ingredient at 900 °C and quenching the melt to produce glass frit. Prepared composites were characterized by various characterization techniques. Scanning electron microscope showed good dispersion of glass particulates in the matrix. However, some porosity was found at higher glass content. Vickers hardness increased by 4 folds for 32 vol% composite. It correlates well a modified rule of mixtures with strengthening efficiency parameter (β) equal to 0.25. The coefficient of thermal expansion (CTE) decreased by 40 % for 32 vol% composite. Experimental CTE is slightly lower than that of theoretical CTE due to the good adhesion between the epoxy and the glass particulates. The moisture absorption of the composites measured at 95 °C follows Fickian diffusion. The parabolic rate constant decreased from 0.20 to 0.022 cm−2 h−1/2 as the glass content increased from 0 to 32 vol%. The 2 h boiling water test showed that the moisture absorption rate of composite decreased by 8 folds compared to pure epoxy.

Keywords

Polymer composites Adhesion Mechanical properties Water resistance

References

1. 1.
   Smay GL (1985) Interactions of organic coatings with metal oxide coatings and glass surface. Glass Technol 26:47–59
2. 2.
   Neumann S, Maron G (1987) Prediction of moisture diffusion parameters in composite materials under stress. J Compos Mater 21:69–79CrossRef
3. 3.
   Hale JM, Gibsum AG (1998) Coupon tests of fiber reinforced plastics at elevated temperatures in offshore processing environments. J Compos Mater 32:387–403CrossRef
4. 4.
   Zheng Q, Morgan RJ (1993) Synergistic thermal moisture damage mechanism of epoxies and their carbon fiber. J Compos Mater 27:1465–1478CrossRef
5. 5.
   Zhou J, Lucas JP (1995) The effects of water environment on anomalous absorption behavior in graphite/epoxy composite. Compos Sci Technol 53:57–64CrossRef
6. 6.
   Janas VF, Mccullough RL (1987) Moisture absorption in unfilled and glass filled crosslinked polyester. Compos Sci Technol 29:293–315CrossRef
7. 7.
   Kim J-K, Hu C, Woo RSC, Sham M-L (2005) Moisture barrier characteristics of organoclay/epoxy nanocomposites. Compos Sci Technol 65:805–813CrossRef
8. 8.
   Abacha N, Kubouchi M, Sakai T (2009) Diffusion behavior of water in polyamide 6 organoclay nanocomposites. Express Polymer Letters 3:245–255CrossRef
9. 9.
   Thomas P., Dwarakanath K., Sampathkumaran P., Seetharamu S., Kishore.: Influence of moisture absorption on electrical characteristics of glass/epoxy polymer composite system. Proceeding of 2005 international symposium on electrical insulating, June 5–9, P2-21 (2005).
10. 10.
    Chow W (2007) S: Water absorption of epoxy/glass fiber/organo montmorillonite nanocomposites. Express Polymer Letters 1:104–108CrossRef
11. 11.
    Wong CP (1999) Comparative study of thermally conductive fillers for use in liquid encapsulants for electronic packaging. IEEE Trans Adv Packaging 22:54–59CrossRef
12. 12.
    Kohraman R, Mamdouh A-H (2005) Moisture diffusion into aluminum powder filled epoxy adhesive in sodium chloride solutions. Int J Adhes Adhes 25:337–341CrossRef
13. 13.
    Ahmed Z, Ansell MP, Smedley D (2010) Effect of nano- and micro-particle additions on moisture absorption in thixotropic room temperature cure epoxy based adhesives for boned in timber connections. Int J Adhes Adhes 30:448–455CrossRef
14. 14.
    Park SY, Choi WJ, Choi HS (2010) The effects of void contents on the long term hygrothermal behaviors of glass/epoxy and GLARE laminates. Compos Struct 92:18–24CrossRef
15. 15.
    Li Y, Cordovez M, Karbhari VM (2003) Dielectric and mechanical characterization of processing and moisture uptake effects in E-glass/epoxy composites. Compos B 34:383–390CrossRef
16. 16.
    Annual book of ASTM standards, 08.01, American Society for Testing and Materials, Philadelphia, USA (1994).
17. 17.
    Goyal RK, Tiwari AN, Negi YS (2008) Microhardness of PEEK/ ceramic micro- and nanocomposites: Correlation with Halpin-Tsai model. Mater Sci Eng, A 491:230–236CrossRef
18. 18.
    Goyal RK, Tiwari AN, Negi YS (2008) Thermal expansion behavior of high performance PEEK matrix composites. J Phys D Appl Phys 41:085403CrossRef
19. 19.
    Lee H, Neville K (1967) Handbook of epoxy resins. McGraw-Hill, Inc., USA

For further details log on website :
http://link.springer.com/article/10.1007%2Fs12588-010-0015-1

How to Use Chinese Medicine Balls for the Hands

Chinese medicine balls Photo Credit Ramonespelt/iStock/Getty Images

Chinese medicine balls, also known as Chinese Baoding balls, stress balls or exercise balls, are said to date back to the Ming Dynasty of 1368-1644, or earlier. While their origins are mysterious, their uses are pragmatic. The balls help to relieve stress, build muscle tone in the hands and fingers and improve circulation. Chinese medicine balls carved from wood or stone are usually more for decoration than exercise. Hollow metal balls that create a chiming sound when they touch are the most common type of medicine balls for therapeutics.

Step 1

Place two Chinese medicine balls in the palm of one hand. Close your palm and fingers over the medicine balls, forming a loose grip.

Step 2

Rotate the Chinese medicine balls clockwise using your fingers and palm. Continue rotating the Chinese medicine balls clockwise, making five complete revolutions.

Step 3

Rotate your fingers and palm counterclockwise, after five clockwise revolutions, spinning the Chinese medicine balls in the opposite direction for an additional five revolutions.

Step 4

Switch hands, placing the Chinese medicine balls in the palm of your other hand. Repeat the clockwise and counterclockwise exercises. Continue switching the Chinese medicine balls from palm to palm for approximately 15 minutes. Repeat the exercise several times per day.

www.livestrong.com

Effects of emulsifier on the bonding performance and freeze–thaw stability of starch-based wood adhesive

Title
Effects of emulsifier on the bonding performance and freeze–thaw stability of starch-based wood adhesive

Author
Zhenjiong Wang , Zhengbiao Gu , Zhaofeng Li , Yan Hong , Li Cheng

Cellulose 2013 v.20 no.5 pp. 2583-2590

Abstract

In this study, different emulsifiers were used to improve the bonding performance and freeze–thaw stability of renewable starch-based wood adhesive. The improved bonding performance and freeze–thaw stability were supported by the enhanced shear strength, grafted parameters, and viscosity stability after repeated freeze–thaw cycling. ζ-Potential determination, differential scanning calorimetry and pulsed nuclear magnetic resonance analysis indicated that the emulsifiers improve the grafting of vinyl acetate monomers into the starch bonds via free radical vinyl polymerization and hinder the aggregation of starch molecules. Among the emulsifiers tested, sodium dodecyl sulfate showed the highest improvement in the bonding performance and freeze–thaw stability of starch-based wood adhesives.

For further details log on website :

http://pubag.nal.usda.gov/pubag/article.xhtml?id=607533&searchText=subject_term%3A%22wood+bonding%22&searchField=

Effects of densification variables on the durability of wood pellets fabricated with Larix kaempferi C. and Liriodendron tulipifera L. sawdust

Title
Effects of densification variables on the durability of wood pellets fabricated with Larix kaempferi C. and Liriodendron tulipifera L. sawdust

Author
Soo min Lee , Byoung Jun Ahn , Don Ha Choi , Gyu-Seong Han , Han-Seob Jeong , Sye HeeAhn , In Yang

Biomass and bioenergy 2013 v.48 pp. 1-9

Abstract

This study was conducted to examine the effects of species, wood particle size, moisture content of wood particles, pelletizing temperature and time on the durability of larch and tulipwood pellets. The durability of larch pellets was significantly higher than that of tulipwood pellets. The larch pellets fabricated with smaller particles were more durable than those fabricated with large particles. The durability of the larch and tulipwood pellets improved steadily with increasing pelletizing time and temperature. In addition, the durability of both pellets increased with increasing moisture content of the sawdust. Scanning electron microscopy (SEM) showed that the surface of the larch and tulipwood pellets fabricated at a pelletizing temperature of 180 °C for 3 min were similar to that of the commercial wood pellets. SEM-energy dispersive X-ray (EDX) analysis showed that lignin, a potential natural binder between wood particles, was spread throughout both the larch and tulipwood pellets with increasing pelletizing temperature and time. These results suggested that the lignin might contribute to the increase in inter-particles bonding in wood pellets.

For further details log on website :

http://pubag.nal.usda.gov/pubag/article.xhtml?id=1120808&searchText=subject_term%3A%22wood+bonding%22&searchField=

Characterisation of the curing of liquefied wood by rheometry, DEA and DSC

Title
Characterisation of the curing of liquefied wood by rheometry, DEA and DSC

Author
Aleš Ugovšek , Milan Sernek

Wood science and technology 2013 v.47 no.5 pp. 1099-1111

Abstract

Liquefied wood is a naturally based product which has the potential to be used as an adhesive. The bonding of wood with liquefied wood requires a high enough temperature to cure the liquid polymers and achieve bond strength. Dielectric analysis, rheometry and differential scanning calorimetry were used to analyse the curing process of low solvent liquefied wood. For the liquefaction, ethylene glycol was used as a solvent and sulphuric acid was used as a catalyst. The dielectric analysis was used for in situ measurements of the curing of liquefied wood during the bonding of wood. It was found that curing started after a temperature of 100 °C had been reached in the bond. This is correlated with the water evaporation and the diffusion of water and ethylene glycol from the liquefied wood into the wood substrate. Rheological measurements proved the influence of the substrate on the curing of the liquefied wood during bonding. Differential scanning calorimetry showed that the curing of liquefied wood occurs in two parts: first, the initial elimination of water and ethylene glycol from the liquefied wood, and then the chemical reaction of the liquefied wood at higher temperatures.

For further details log on website :

http://pubag.nal.usda.gov/pubag/article.xhtml?id=603526&searchText=subject_term%3A%22wood+bonding%22&searchField=

Starch-sugar synergy in wood adhesion science: basic studies and particleboard production

Title
Starch-sugar synergy in wood adhesion science: basic studies and particleboard production

Author
G. Tondi , S. Wieland , T. Wimmer , T. Schnabel , A. Petutschnigg

European Journal of Wood and Wood Products 2012 v.70 no.1-3 pp. 271-278

Abstract

Synergic properties between starch and sugar were discovered. 100% crop-based starch and sugar formulations were studied. Classical preliminary tests such as curing temperature and gel time were measured for different starch-sucrose water suspensions. More significant information was deducted with applied tests such as plywood gluing tests and particleboard production. Wood-to-wood bonding properties were analysed applying NaOH and high temperature (180°C) as catalysts for starch gelification. Comparable strength to commercial urea-formaldehyde and polyvinyl acetate adhesives was achieved in plywood tests. Consequently, the knowledge acquired in wood bonding of flat surfaces was applied to particleboard production. These derived particleboards showed that it is possible to obtain a panel with only carbohydrates as gluing agent. Starch-sugar synergy in alkaline environment increases the internal bond (IB) of the natural panels up to 0.25 N/mm2. Possible mechanisms of synergy between these saccharides were proposed. Finally, a blended formulation with Mimosa tannin allows for achieving an internal bond of 0.40 N/mm2, which is the required value for interior grade particleboards (DIN EN 312). Starch-sugar-tannin adhesives are 100% environmentally-friendly formulations.

For further details log on website :

http://pubag.nal.usda.gov/pubag/article.xhtml?id=471416&searchText=subject_term%3A%22wood+bonding%22&searchField=

How to Get Rid of Fat Pockets Under Your Eyes

Woman applies eye cream in the mirror. Photo Credit Keith Spaulding/iStock/Getty Images

Most people have fat deposits under their eyes, but as some age, the fat deposits migrate toward the surface of the face and give a puffy, swollen appearance. While genetics play a major role in whether a person develops puffy bags under the eyes, other factors such as sleep and eating habits also contribute to the size of the fat deposits. One of the more common ways in which to permanently remove puffy fat deposits is cosmetic surgery, but this option may be too drastic for some people. In such cases, some minor lifestyle changes can improve the appearance of eye fat deposits.

Step 1

Place a frozen or chilled eye mask on your eyes for 15 minutes each day. The coldness causes the skin to tighten up, which may reduce the eye puffiness. This can be done at any time of the day.

Step 2

Get at least eight hours of sleep each night and make sure your head is slightly elevated above the rest of your body. A lack of sleep can cause tired, weak muscles which may increase the size of the bags beneath the eyes.

Step 3

Avoid alcohol, caffeine and excessive salt as much as possible. All of these can result in water retention which may take place under the eyes.

Step 4

Drink at least eight glasses of water per day to ensure your body stays hydrated. If your body gets a constant supply of water, it's less likely to retain excess water in various parts of the body, including the eye area.

Tips

• Allergies may cause the fat deposits to swell. See a doctor if they begin to grow rapidly.

www.livestrong.com

Pre-Running Stretches

Two young women stretching before a run. Photo Credit oneinchpunch/iStock/Getty Images

For years, static stretching before running was believed to have many benefits, but recent studies have shown otherwise. Pre-run dynamic stretches are actually much more beneficial. Performed while moving and held for less time than a static stretch, dynamic stretches prepare your body by increasing your heart rate, opening joints, actively stretching muscles and reinforcing good posture. There are a variety of dynamic stretches you can do to prepare for your run.

Hip Circles

Hip circles are an effective dynamic stretch for your hips. Place your hands on your hips with your feet shoulder-width apart and toes pointed forward. Make circles with your hips in a clockwise direction. Repeat the circles in a counter clockwise direction. Complete 10 reps in each direction with a full range of motion.

Quad Pulls

Quads pulls are a common but effective dynamic stretch for your quads. Stand straight with your feet shoulder-width apart and toes pointed forward. Lift one leg up towards your glutes. As you lift your leg, reach back and grab your ankle with your opposite hand. Pull your ankle towards your glutes until you feel a stretch in your quad, and hold this position for two seconds. Slowly lower your leg, and repeat this stretch with your opposite leg and opposite hand. Keep your torso straight while performing this stretch. Complete 10 to15 reps on each leg.

Leg Swings

Leg swings are a bit more advanced than the previous two stretches. They target your hamstrings, glutes and quads. First stand parallel to a hand rail with your feet shoulder-width apart and your toes pointed forward. Place your outside hand on your outside hip, and grab the hand rail with your inside hand. With a slight knee bend, swing your inside leg forward until you feel a stretch in your hamstring. As your leg comes down, swing it backward and attempt to kick yourself in the glutes until you feel a stretch in your quad. Gradually increase your range of motion with each rep. Perform 10 to15 reps on each leg.

Power Skip

Power skips target your arms, shoulders, core, hips, glutes, quads, hamstrings and calves. Using a skipping motion, swing one arm straight up and raise your opposite knee as high as possible. If done properly, you should float briefly in the air. As your arm and knee come down, repeat the motion with the opposite arm and opposite knee. Focus on height instead of distance. Complete 20 to 30 reps.

www.livestrong.com

Basic Stretching Exercises for Men

Before you begin a workout, you should warm up with some stretching. Photo Credit Stockbyte/Stockbyte/Getty Images

A study conducted at the University of British Columbia found that stretching makes men less prone to injuries than women. It's an essential way to loosen up the muscles before and after a workout. Whether you're running, cycling or power-lifting, you can bet that stretching will maximize your performance. There are static stretches which are great for everyday routines, dynamic stretches which charge up your body before a workout and active stretching which incorporates resistance bands to lengthen and strengthen your muscles.

Quadriceps and Hamstrings

The quadriceps and the hamstring muscles in your thigh are two major muscle groups that you can stretch daily. To stretch the hamstrings, on the back of the thigh, simply sit on the floor with your legs straight and spread apart. Lean your upper body down toward your leg, reaching your arms toward your toes. Hold the stretch for roughly 20 seconds and alternate sides. To work the quadriceps on the outer thigh, transition to lying on one side and brace your weight with an extended arm. Pull the top leg backwards, behind your body and hold this position. Roll over to the opposite side, and pull back on the foot. The deeper you pull the foot behind your body, the more intense the stretch on your thigh.

ITB Stretch for Runners

The iliotibial band is the long ligament that travels from the hip to the knee along the outside of the thigh. Often called the ITB, or IT band, this ligament is crucial for the performance of runners and sports athletes. You can perform the ITB hip stretch from a seated position. Bend both legs at the knee and cross one leg over the other. Wrap your opposite arm around the crossing leg and pull it close to your chest. You can deepen the stretch on your hip by rolling onto your back and pulling the extended leg toward your chest also.

Stretches for the Back and Hips

The muscles of the hip and lower back are essential for day-to-day core movements. Performing a dynamic stretch, or warm-up, can help increase circulation and help prevent injuries associated with the lower back. Alternating toe touches stretch the lower back and prepare you for more rigorous exercises. Stand with your legs spread slightly wider than shoulder width. Hold your arms straight out to your sides at 180 degrees. Now, bend at the waist and touch your right hand to your left foot. Straighten the back and alternate with the left hand touching the right foot.

Arms and Shoulders

To bring more flexibility to your arms and shoulders, try some dynamic arm rotations. Stand with your legs shoulder-width apart and place your arms out to your sides at 180 degrees. Now, swing the arms in a forward circular motion. After about 30 seconds, change the rotation and swing the arms backwards. Also, swing the arms in front of the body, alternating from the left to the right side. Keep your arms fully extended at the elbow and allow your arms to swing naturally. This action loosens up the rotator cuff, which is the collection of tendon and bone where the upper arm meets the shoulder.

www.livestrong.com

How to Make Garden Huckleberry Jam

A homemade glass of jam. Photo Credit saquizeta/iStock/Getty Images

If you are not sure what to do with garden huckleberries, make some jam to enjoy through the winter months. Homemade jam has no chemical preservatives, making it a better option than the store-bought varieties. The right mix of berries, acid from lemon juice, pectin and sugar creates a gel consistency that spreads nicely on toast, sandwiches or crackers. One batch of jam makes 5 to 6 half-pints or 2 to 3 pints.

Step 1

Wash your huckleberries with water, and place them in a colander to drip-dry.

Step 2

Pick through the berries and remove stems, debris and berries that appear rotten.

Step 3

Place a 1-inch layer of berries in a large mixing bowl, and crush them with a potato masher. Pour the mashed berries into a large saucepan and repeat until you crush them all.

Step 4

Add the lemon juice and water to your saucepan, and stir to combine. Pour the pectin into your berries while stirring.

Step 5

Place the saucepan onto your stove, and turn the heat to high. Stir continuously while bringing the mixture to a boil.

Step 6

Pour the sugar into your saucepan, and stir to combine while bringing the mixture back to a boil. Boil for one minute -- stirring continuously to prevent burning or foaming out of the pan -- and remove from heat.

Step 7

Skim the foam off the top of the mixture with a mesh or slotted spoon and discard.

Step 8

Scoop or pour the huckleberry mixture into pint or half-pint sterilized canning jars to 1/4-inch from the rim. Place a boiled canning lid on top of the jars, and secure with jar rings.

Step 9

Process the jars in a hot-water bath canner for five minutes for shelf storage or place in a freezer for up two months. Process the jam 10 minutes for altitudes over 1,000 feet.

Tips

• Make small batches instead of doubling the recipe to keep the mixture at the correct ratio and consistency for processing.
• Mix in blueberries or blackberries if you do not have enough huckleberries for the batch.

Things You'll Need

• 6 cups huckleberries
• Colander
• Mixing bowl
• Potato masher
• 1 tbsp. lemon juice
• 3/4 cups water
• 1 package powdered pectin
• 5 cups sugar
• Slotted spoon or mesh

www.livestrong.com