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Monday 1 August 2016

Electrolyte Imbalance Signs

Electrolyte Imbalance Signs
Electrolyte Imbalance Signs Photo Credit Jupiterimages/Photos.com/Getty Images
Electrolytes are minerals in your body that have an electric charge. There must be a balance between the electrolytes with positive charges and those with negative charges, and all must stay within a certain range. If that balance is lost or if they stay outside the normal range, it can be harmful. The main electrolytes include sodium, potassium and calcium. Sodium and potassium are important for your nervous system, while potassium is also important for your heart. Your muscles need the proper amounts of calcium.

Hypernatremia

Hypernatremia is the name that is used if the sodium levels in your blood are higher than the normal value; that is, higher than 145 mEq/L. At first, you may only feel thirsty, but if your levels are not corrected, you will start to feel irritable and weak. If the sodium levels continue to rise, you will now have what is referred to as severe hypernatremia, levels higher than 158 mEq/L. At this point, you can become delirious, disoriented, have seizures and even go into a coma.

Hyponatremia

This term is used to define blood sodium levels lower than 135 mEq/L. With hyponatremia, as explained by Dr. Cho, Assistant Clinical Professor of Medicine at the University of California, you will not have any symptoms with levels at 130 mEq/L. Even at 110 mEq/L, you will not have symptoms if your levels drop slowly over a period of weeks to months, because your brain will have time to adjust. Levels that drop rapidly will make you nauseous. And then, you will have headaches and become disoriented. If this is not corrected, you can have seizures and go into respiratory arrest and a coma.

Hyperkalemia

Potassium levels higher than 5 mEq/L is referred to as hyperkalemia. You may not have any symptoms, but if your levels reach higher than 6.5 mEq/L, then the signals that go from your nerves to your muscles will be impaired. This will give you paralysis, make your muscles weak and lessen your reflexes. Because nerves also stimulate your heart muscle, you can also have cardiac changes.

Hypokalemia

Potassium levels lower than 3.5 mEq/L is defined as hypokalemia. Once again, your muscles are affected. You will have cramps, muscle weakness and even constipation. If your levels drop below 2.5 mEq/L, you can have poor reflexes and paralysis.

Hypercalcemia

If your blood’s calcium levels are higher than 10.2 mg/dL, this is considered to be hypercalcemia. Medical students across the country have memorized the phrase “bones, stones, abdominal groans, psych overtones,” for these are the symptoms of hypercalcemia--bone fractures, kidney stones, the “abdominal groans” of vomiting and constipation. “Psych overtones” leave you feeling tired and weak, with a change in your mental alertness.

Hypocalcemia

Calcium levels lower than 8.5 mg/dL are considered as hypocalcemia. Dr. Cho writes that hypocalcemia makes the muscle cells and the nerve cells more excitable. Thus, the symptoms include muscle spasms, which cause cramps. You can also have abdominal pain and convulsions. You will have a facial spasm if your physician taps your facial nerve. This is called the Chvostek’s sign.
www.livestrong.com

What Drink for Adults Is High in Electrolytes?

What Drink for Adults Is High in Electrolytes?
Milk may be the next best thing to sports drinks. Photo Credit Blackzheep/iStock/Getty Images
If you don't take in enough electrolytes, or if you lose them rapidly through sweat or urine, you may experience muscle cramps, irregular heartbeat, nausea and confusion. You need electrolytes to transmit messages throughout your nervous system, contract your muscles and maintain fluid balance. Consume foods and drinks that contain the electrolyte minerals sodium, potassium, phosphorus, magnesium and calcium daily.

It Does a Body Good

Drink low-fat or fat-free milk to replace electrolytes. One cup provides about 30 percent of your daily calcium and phosphorus requirements, as well as 6 percent to 8 percent of your daily needs for sodium, potassium and magnesium. Milk may be just as effective as sports drinks in replacing nutrients after exercise, according to the National Dairy Council.

Dairy-Free Alternatives

Coconut water is another electrolyte-rich option to quench your thirst. A cup contains almost 20 percent of your daily sodium and magnesium needs. You'll also get 13 percent of the potassium and 7 percent of the phosphorus you need in a day. If you exercise for more than an hour and you sweat profusely, you may need a sports drink to replace electrolytes, according to the American Council on Exercise.
www.livestrong.com

Evaluating the durability performance of wood-based panels by a non-destructive bending test

Published Date
Volume 62, Issue 3, pp 263-269
First online: 

Title 

Evaluating the durability performance of wood-based panels by a non-destructive bending test

  • Author 
  • Yoichi Kojima 
  • Akira Sakakibara
  • Hikaru Kobori
  • Shigehiko Suzuki

Abstract

We evaluated the durability of wood-based panels by comparing their dynamic modulus of elasticity (Ed) when subjected to repetitive humid and dry treatments. The panels experienced 1-year and 3-month outdoor exposure periods in Shizuoka City, Japan. As the temperature increased, decrements of Ed retention increased. For the same relative humidity, deterioration of the wood-based panels increased with increasing temperature. The highest modulus of rupture (MOR) retention for all the panels was for the 40 °C treatment. As temperature increased, MOR retention tended to decrease. At the 80 °C treatment, MOR retention for particle board (PB) was less than 10 %. Compared to plywood (PW), retention of mat-formed boards declined. One of reasons is due to the difference of bonding configuration. Bonding point of plywood is plain surface, however, that of mat formed board is small point. Thus, bonding points of board are easily collapsed by the ingress of water. Furthermore, mat-formed boards are likely to spring back by water because they are strongly compressed during hot pressing. Ed retention of all the panels decreased within 2 months. After 2 months, the Ed retention of two types of oriented strandboard (OSB) and PW did not decrease significantly. Ed retention of PB gradually decreased. The deterioration behaviour of the same sample during both humid and dry treatments and the outdoor exposure test could be tracked using the non-destructive bending test. Moreover, although the mechanism of deterioration differed between the humid and dry treatment and outdoor exposure test, Ed and MOR were strongly associated (R 2 = 0.77). These results suggest that it is feasible to estimate MOR from Ed using the non-destructive test.

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For further details log on website :
http://link.springer.com/article/10.1007/s10086-016-1545-8

Low cycle fatigue tests and damage accumulation models on the rolling shear strength of cross-laminated timber

Published Date
Volume 62, Issue 3, pp 251-262
First online: 

Title 

Low cycle fatigue tests and damage accumulation models on the rolling shear strength of cross-laminated timber

  • Author 
  • Yuan Li 
  • Frank Lam

Abstract

This paper presents a study on rolling shear damage accumulation and duration of load of cross-laminated timber (CLT) with low cycle fatigue tests. The study of the duration-of-load (DOL) effect on strength properties of wood products is typically challenging; it may be more challenging for non-edge-glued CLT considering crosswise layups of wood boards, existing gaps, and non-uniform stress distributions in cross layers. In experimental studies, short-term ramp loading tests and low cycle trapezoidal fatigue loading tests were used to study the DOL behaviour of the CLT rolling shear. The ramp tests were performed to establish the short-term CLT rolling shear strength properties. The low cycle trapezoidal fatigue tests were performed to evaluate the damage accumulation process for the matched specimens under controlled rolling shear stress levels. A stress-based damage accumulation model was further used to investigate the rolling shear DOL effect with model parameters treated as random variables calibrated against one set of the test data. The calibrated model predicted well comparing with the other set of the test data. This verified model provides a robust tool to quantify the DOL effect on rolling shear strength in the core layers of CLT that can be used in future studies of DOL behaviour in CLT under arbitrary loading histories.


References

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    FP Innovations (2011) CLT handbook—Chapter 3 structural design of cross-laminated timber elements. Vancouver, British Columbia
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    Blass HJ, Fellmoser P (2004) Design of solid wood panels with cross layers. Proceedings of the 8th world conference on timber engineering, WCTE 2004, June 14–17, 2004, Lahti, Finland, pp 543–548
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    Aicher S, Dill-Langer G (2000) Basic considerations to rolling shear modulus in wooden boards. Otto-Graf-J 11:157–166
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    Blass HJ, Görlacher R (2003) Brettsperrholz. Berechnungsgrundlagen (in German). Holzbau Kalender, Bruder, Karlsruhe, pp 580–598
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    Fellmoser P, Blass HJ (2004) Influence of RS modulus on strength and stiffness of structural bonded timber elements. CIB-W18/37-6-5, Edinburgh, UK
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    Jöbstl RA, Schickhofer G (2007) Comparative examination of creep of glulam and CLT slabs in bending. CIB-W18/40-12-3, Bled, Slovenia
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For further details log on website :
http://link.springer.com/article/10.1007/s10086-016-1547-6

A Theoretical Model of Collapse Recovery

Published Date
Date: 

Title 

A Theoretical Model of Collapse Recovery

  • Author 
  • Philip Blakemore

Abstract

The theory that is thought to best explain the recovery of collapse reconditioning supposes that the S1 and S3 layers are largely responsible for providing restoring the cells to the un-collapsed shape. This is because these two layers are particularly important in providing circumferential stiffness to each individual cell lumen. Hence, it is the potential energy stored in these layers that principally provides the force to restore the cell shape. In contrast, the S2 layer is considered to be the most important for providing the inelastic material properties required to hold the cell in the collapsed or deformed state. While moisture content is important for its effect on the cell wall material properties (i.e. stiffness, creep, mechano-sorptive creep), the uptake or movement of moisture within the cell walls is not thought to be critical for collapse recovery. In this sense, the recovery phenomenon can largely be attributed to a thermal effect (Blakemore and Langrish, 2008), and hence it is the relationships with temperature for the various material properties which are critical for this modelling work. The effect of heat then is to soften the S2layer, which is holding the cell in the deformed shape, allowing the stored mechanical energy in the S1 and S3layers to restore the cell shape.

References

  1. Astley RJ, Stol KA, Harrington JJ (1998) Modelling the elastic properties of softwood. Part II: The cellular microstructure. Holz Roh Werkst 56:43–50CrossRef
  2. Blakemore P (2008) Optimisation of steam reconditioning for regrowth-ash and plantation grown eucalypt species.PhD Thesis, The University of Sydney. 327 pp. http://​hdl.​handle.​net/​2123/​2343. Accessed 3 August 2010
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For further details log on website :
http://link.springer.com/chapter/10.1007/978-90-481-9550-3_5

Advantages and Disadvantages of Fasting for Runners

Author BY   ANDREA CESPEDES  Food is fuel, especially for serious runners who need a lot of energy. It may seem counterintuiti...