What is stress concentration

Here's what to do when your mind tends to wander. Everyone's attention can drift at times, like when you lose your concentration for a moment while doing routine tasks. Many people shrug off these lapses in focus as "senior moments," but they might be related to a vulnerable brain process called executive function. "Your brain's executive function helps you plan, make decisions, and — perhaps most important — pay attention," says Dr. Joel Salinas, a neurologist with Harvard-affiliated Massachusetts General Hospital. "It acts much like the captain of the ship." A slow, gradual decline Your executive function peaks alongside other brain functions in your early 20s and then gradually diminishes over time. Fortunately, the process is quite slow, says Dr. Salinas. Everyone's brain is wired and programmed differently, and some people struggle with attention more than others. But if you notice any sudden change in your ability to concentrate — for example, if you have a harder time finishing routine tasks and chores, regularly misplace essential items, make more errors than you used to in your day-to-day life, or make more frequent poor decisions — don't ignore it. Speak with your doctor, says Dr. Salinas. Such symptoms may be due to an underlying condition, like mild cognitive impairment, or a mood disorder, like depression and anxiety. Declining focus also could result from lifestyle issues that should be addressed, such as stress, fatigue, poor sleep, dehydration, an unhealthy...

Stress Concentration Factor An SCF can be defined as the ratio of the hot-spot stress range over the nominal stress range. From: Marine Structural Design (Second Edition), 2016 Related terms: • Stress Concentration • Fatigue Life • Joints (Structural Components) • Welds • Nominal Stress • Stress Range Fatigue Capacity Yong Bai, Wei-Liang Jin, in Marine Structural Design (Second Edition), 2016 25.3.3Parametric Equations for SCFs Given that a variety of SCFs need to be estimated on any given tubular joint, SCF determinations have to rely more on sets of parametric equations that account for joint geometry configurations and applied loadings. (25.11) S C F = S C F g · S C F w · S C F t e · S C F t a · S C F n where, SCF g= Stress concentration factor due to gross geometry of the detail considered SCF W=Stress concentration factor due to weld geometry SCF te=Additional SCF due to eccentricity tolerance (normally used for plate connections only) SCF ta=Additional SCF due to angular mismatch (normally used for plate connections only) SCF n=Additional SCF for unsymmetrical stiffeners on laterally loaded panels, applicable when the nominal stress is derived from simple beam analysis The best-known SCF formulae for the fatigue assessment of offshore structures are those of Efthymiou (1988). There are various parametric equations in the literature for the determination of SCFs. F, for instance: • SCF equations for tubular connections: API RP2A-WSD, NORSOK N-004 ( NTS, 1998) and Efth...

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Meditation has been practiced for thousands of years. Meditation originally was meant to help deepen understanding of the sacred and mystical forces of life. These days, meditation is commonly used for relaxation and stress reduction. Meditation is considered a type of mind-body complementary medicine. Meditation can produce a deep state of relaxation and a tranquil mind. Meditation can give you a sense of calm, peace and balance that can benefit both your emotional well-being and your overall health. You can also use it to relax and cope with stress by refocusing your attention on something calming. Meditation can help you learn to stay centered and keep inner peace. And these benefits don't end when your meditation session ends. Meditation can help carry you more calmly through your day. And meditation may help you manage symptoms of certain medical conditions. Meditation and emotional and physical well-being When you meditate, you may clear away the information overload that builds up every day and contributes to your stress. The emotional and physical benefits of meditation can include: • Gaining a new perspective on stressful situations • Building skills to manage your stress • Increasing self-awareness • Focusing on the present • Reducing negative emotions • Increasing imagination and creativity • Increasing patience and tolerance • Lowering resting heart rate • Lowering resting blood pressure • Improving sleep quality Meditation and illness Meditation might also be ...

A number of medical conditions may contribute to or cause an inability to concentrate. It’s not always a medical emergency, but being unable to concentrate can mean you need medical attention. You rely on concentration to get through work or school every day. When you can’t concentrate, you can’t think clearly, focus on a task, or maintain your attention. Your performance at work or school could be affected if you can’t concentrate. You may also find that you can’t think as well, which can affect your decision-making. Read on to learn more about difficulty concentrating and the possible causes. Being unable to concentrate affects people differently. Some symptoms you may experience include: • being unable to remember things that occurred a short time ago • difficulty sitting still • difficulty thinking clearly • frequently losing things or having difficulty remembering where things are • inability to make decisions • inability to perform complicated tasks • lack of focus • lacking physical or mental energy to concentrate • making careless mistakes You may notice that it’s harder to concentrate at certain times of day or in certain settings. Others may comment that you appear distracted. You may miss appointments or meetings because of a lack of focus. Sometimes, people call this Many health conditions can make it hard to concentrate. Here are just a few: • • • • • • • • • • • • • Lifestyle factors that can affect your concentration include: • lack of sleep • hunger • lack ...

Geometric discontinuities cause localized stress increases above the average or far-field stress. A stress raiser's effect can be determined quantitatively in several ways, but not always readily. The simplest method, if applicable, is to use a known theoretical stress concentration factor , K t , to calculate the peak stress from the nominal, or average, value; The factor K t depends mainly on the geometry of the notch, not on the material, except when the material deforms severely under load. K t values are normally obtained from plots such as in Figure 2 and arestrictly valid only for ideally elastic, stiff members. K t values can also be determined by FEA or by several experimental techniques. There are no K t values readily available for sharp notches and cracks, but one can always assume that such discontinuities produce the highest stress concentrations, sometimes factors of tens. This is the reason for brittle, high-strength materials being extremely sensitive even to minor scratches. In fatigue, for example, invisible toolmarks may lead to premature, unexpected failures in strong steels. wherep is the radius of curvature of the crack tip. A stress concentration factor is the ratio of the highest stress ( s max )) to a reference stress ( s) of the gross cross-section. As the radius of curvature approaches zero, the maximum stress approaches infinity. Note that the stress concentration factor is a function of the geometry of a crack, and not of its size. These facto...