Environmental factors for site‐to‐site differences in low‐frequency surface scatter

1998 ◽  
Vol 104 (3) ◽  
pp. 1821-1821
Author(s):  
Jeffrey L. Hanson
Keyword(s):  
Environmental Factors ◽  
Low Frequency ◽  
Surface Scatter

Influence of HA and Environmental Factors to the Damping Performance of HA/Mg-3Zn-0.5Zr Composites

2016 ◽  
Vol 849 ◽  
pp. 416-423
Author(s):  
Chen You ◽  
Hao Ran Zheng ◽  
Dan Dan Jin ◽  
Lei Wang ◽  
Meng Meng Wang ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Strain Amplitude ◽  
Low Frequency ◽  
High Strength ◽  
Thermomechanical Analysis ◽  
Optical Microscope ◽  
Vacuum Induction Melting ◽  
Induction Melting ◽  
Important Approach ◽  
Damping Theory

Vibration and noise are the dangers for equipment, human health and environment. Developing of a new Mg matrix composite with high damping performance and high strength rate has been acknowledged as an important approach for the reduction of vibrations and prevention of noise. In this paper, xHA/Mg-3Zn-0.5Zr (x=0.5wt.%, 1wt.%, 1.5wt.%) composites were prepared by vacuum induction melting and hot extruding. The microstructure and damping performance were observed and measured using an optical microscope and a dynamic thermomechanical analysis apparatus (DMA), respectively. The influence of HA and environmental factors (temperature, frequency and strain amplitude) on the damping performance of HA/Mg-3Zn-0.5Zr composites were studied. The results showed that the damping performance of HA/Mg-3Zn-0.5Zr composites increased with increasing HA content and strain amplitude. The damping mechanism was in line with the G-L theory and interface damping theory. The damping values were strongly amplified at 150-300°C. The plot of damping versus temperature showed a peak for the Mg-3Zn-0.5Zr-1HA composite at 235°C. The low frequency damping values of xHA/Mg-3Zn-0.5Zr were higher than the high frequency damping values. It is suggested that the change of damping by a variety of external factors is due to the presence of different dominant damping mechanism at different conditions. Furthermore, it was found that at increased HA content, the grain size of HA/Mg-3Zn-0.5Zr composites decreased and the tensile strength and elongation of HA/Mg-3Zn-0.5Zr composites improved. This work will be beneficial for the study of Mg based joint implant materials with high vibration damping performance.

Modeling low‐frequency surface scatter intensity statistics

1996 ◽  
Vol 100 (4) ◽  
pp. 2799-2799 ◽  
Author(s):  
Eric I. Thorsos ◽  
Donald B. Percival ◽  
Kate M. Bader
Keyword(s):  
Low Frequency ◽  
Scatter Intensity ◽  
Surface Scatter

scholarly journals Influences of environmental factors on low frequency abnormal sound transmission through sea-air interface

2015 ◽  
Vol 64 (14) ◽  
pp. 144301
Author(s):  
Guo Ye-Cai ◽  
Lian Chen-Fang ◽  
Zhang Xiu-Zai ◽  
Zhao Yi-Bo
Keyword(s):  
Environmental Factors ◽  
Low Frequency ◽  
Sound Transmission ◽  
Air Interface ◽  
Abnormal Sound

EUROPAEM EMF Guideline 2016 for the prevention, diagnosis and treatment of EMF-related health problems and illnesses

2016 ◽  
Vol 31 (3) ◽  
Author(s):  
Igor Belyaev ◽  
Amy Dean ◽  
Horst Eger ◽  
Gerhard Hubmann ◽  
Reinhold Jandrisovits ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Magnetic Fields ◽  
Adverse Effects ◽  
Low Frequency ◽  
Health Problems ◽  
The Body ◽  
Individual Susceptibility ◽  
Electrical Wiring ◽  
At Home

AbstractChronic diseases and illnesses associated with non-specific symptoms are on the rise. In addition to chronic stress in social and work environments, physical and chemical exposures at home, at work, and during leisure activities are causal or contributing environmental stressors that deserve attention by the general practitioner as well as by all other members of the health care community. It seems necessary now to take “new exposures” like electromagnetic fields (EMF) into account. Physicians are increasingly confronted with health problems from unidentified causes. Studies, empirical observations, and patient reports clearly indicate interactions between EMF exposure and health problems. Individual susceptibility and environmental factors are frequently neglected. New wireless technologies and applications have been introduced without any certainty about their health effects, raising new challenges for medicine and society. For instance, the issue of so-called non-thermal effects and potential long-term effects of low-dose exposure were scarcely investigated prior to the introduction of these technologies. Common electromagnetic field or EMF sources: Radio-frequency radiation (RF) (3 MHz to 300 GHz) is emitted from radio and TV broadcast antennas, Wi-Fi access points, routers, and clients (e.g. smartphones, tablets), cordless and mobile phones including their base stations, and Bluetooth devices. Extremely low frequency electric (ELF EF) and magnetic fields (ELF MF) (3 Hz to 3 kHz) are emitted from electrical wiring, lamps, and appliances. Very low frequency electric (VLF EF) and magnetic fields (VLF MF) (3 kHz to 3 MHz) are emitted, due to harmonic voltage and current distortions, from electrical wiring, lamps (e.g. compact fluorescent lamps), and electronic devices. On the one hand, there is strong evidence that long-term exposure to certain EMFs is a risk factor for diseases such as certain cancers, Alzheimer’s disease, and male infertility. On the other hand, the emerging electromagnetic hypersensitivity (EHS) is more and more recognized by health authorities, disability administrators and case workers, politicians, as well as courts of law. We recommend treating EHS clinically as part of the group of chronic multisystem illnesses (CMI), but still recognizing that the underlying cause remains the environment. In the beginning, EHS symptoms occur only occasionally, but over time they may increase in frequency and severity. Common EHS symptoms include headaches, concentration difficulties, sleep problems, depression, a lack of energy, fatigue, and flu-like symptoms. A comprehensive medical history, which should include all symptoms and their occurrences in spatial and temporal terms and in the context of EMF exposures, is the key to making the diagnosis. The EMF exposure is usually assessed by EMF measurements at home and at work. Certain types of EMF exposure can be assessed by asking about common EMF sources. It is very important to take the individual susceptibility into account. The primary method of treatment should mainly focus on the prevention or reduction of EMF exposure, that is, reducing or eliminating all sources of high EMF exposure at home and at the workplace. The reduction of EMF exposure should also be extended to public spaces such as schools, hospitals, public transport, and libraries to enable persons with EHS an unhindered use (accessibility measure). If a detrimental EMF exposure is reduced sufficiently, the body has a chance to recover and EHS symptoms will be reduced or even disappear. Many examples have shown that such measures can prove effective. To increase the effectiveness of the treatment, the broad range of other environmental factors that contribute to the total body burden should also be addressed. Anything that supports homeostasis will increase a person’s resilience against disease and thus against the adverse effects of EMF exposure. There is increasing evidence that EMF exposure has a major impact on the oxidative and nitrosative regulation capacity in affected individuals. This concept also may explain why the level of susceptibility to EMF can change and why the range of symptoms reported in the context of EMF exposures is so large. Based on our current understanding, a treatment approach that minimizes the adverse effects of peroxynitrite – as has been increasingly used in the treatment of multisystem illnesses – works best. This EMF Guideline gives an overview of the current knowledge regarding EMF-related health risks and provides recommendations for the diagnosis, treatment and accessibility measures of EHS to improve and restore individual health outcomes as well as for the development of strategies for prevention.

Mollusk Shell Growth: External Microgrowth Ridge Formation is Uncoupled to Environmental Factors in Mytilus edulis

1992 ◽  
Vol 49 (6) ◽  
pp. 1163-1170 ◽  
Author(s):  
Hélène Bérard ◽  
Edwin Bourget ◽  
Marcel Fréchette
Keyword(s):  
Environmental Factors ◽  
Mytilus Edulis ◽  
Field Experiments ◽  
Blue Mussel ◽  
Shell Growth ◽  
Low Frequency ◽  
Growth Patterns ◽  
Ridge Pattern ◽  
Similar Growth ◽  
External Growth

Low-frequency (e.g. annual) external ridges have been used in the study of bivalve population dynamics, and it has been suggested that ridges produced at high frequencies are related to environmental factors. Using laboratory and field experiments, we examined the usefulness of fine external growth ridges as markers of cyclic growth patterns in the blue mussel, Mytilus edulis. Shells of M. edulis were analyzed to examine coherence of patterns of ridges on the shells. Analysis was carried out in two steps: (1) An objective method was developed to characterize the ridges by their height and thickness (precision 0.5 μm) and (2) laboratory and field experiments were carried out to determine the influence of environmental factors (immersion and emersion, algal concentration) and biological factors (valve closure) on the periodicity of growth ridge formation. All mussels exhibited unique growth ridge patterns. There was no concordance between growth ridge patterns of individual mussels grown together in the laboratory or in the field. These results refute the hypothesis of a similar growth ridge pattern between individuals in Mytilus at small scales. No relation was found between the mechanical closure of the valves and the formation of growth ridges.

Reductionist thinking and animal models in neuropsychiatric research

2019 ◽  
Vol 42 ◽  
Author(s):  
Nicole M. Baran
Keyword(s):  
Animal Models ◽  
Mental Disorders ◽  
Environmental Factors ◽  
Neuropsychiatric Disorders ◽  
Model Organisms ◽  
Developmental Genetic ◽  
Term Study ◽  
Genetic And Environmental Factors ◽  
Mechanisms Of Plasticity

AbstractReductionist thinking in neuroscience is manifest in the widespread use of animal models of neuropsychiatric disorders. Broader investigations of diverse behaviors in non-model organisms and longer-term study of the mechanisms of plasticity will yield fundamental insights into the neurobiological, developmental, genetic, and environmental factors contributing to the “massively multifactorial system networks” which go awry in mental disorders.

A Study on the Fine Structure of the Lateral Line Organ of the Sea Eel

1973 ◽  
Vol 31 ◽  
pp. 648-649
Author(s):  
K. Hama
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Lateral Line ◽  
Low Frequency ◽  
Sensory Cells ◽  
Apical Surface ◽  
Voltage Electron ◽  
Sensory Epithelia ◽  
Low Frequency Vibration ◽  
Transmission Electron

The lateral line organs of the sea eel consist of canal and pit organs which are different in function. The former is a low frequency vibration detector whereas the latter functions as an ion receptor as well as a mechano receptor.The fine structure of the sensory epithelia of both organs were studied by means of ordinary transmission electron microscope, high voltage electron microscope and of surface scanning electron microscope.The sensory cells of the canal organ are polarized in front-caudal direction and those of the pit organ are polarized in dorso-ventral direction. The sensory epithelia of both organs have thinner surface coats compared to the surrounding ordinary epithelial cells, which have very thick fuzzy coatings on the apical surface.

Lectin Binding to Human Breast Tumor Cells

1976 ◽  
Vol 34 ◽  
pp. 34-35
Author(s):  
Robert E. Nordquist ◽  
J. Hill Anglin ◽  
Michael P. Lerner
Keyword(s):  
Carcinoma Cell ◽  
Ricinus Communis ◽  
Lectin Binding ◽  
Low Frequency ◽  
Breast Carcinoma Cell Line ◽  
Human Breast ◽  
Human Breast Tumor ◽  
Duct Carcinoma ◽  
Specific Antigens ◽  
Ricin Agglutinin

A human breast carcinoma cell line (BOT-2) was derived from an infiltrating duct carcinoma (1). These cells were shown to have antigens that selectively bound antibodies from breast cancer patient sera (2). Furthermore, these tumor specific antigens could be removed from the living cells by low frequency sonication and have been partially characterized (3). These proteins have been shown to be around 100,000 MW and contain approximately 6% hexose and hexosamines. However, only the hexosamines appear to be available for lectin binding. This study was designed to use Concanavalin A (Con A) and Ricinus Communis (Ricin) agglutinin for the topagraphical localization of D-mannopyranosyl or glucopyranosyl and D-galactopyranosyl or DN- acetyl glactopyranosyl configurations on BOT-2 cell surfaces.

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