Long distance source localization in waveguides with complicated structure

Based on Hanbury Brown-Twiss (HBT) interference in the sound field, a space positioning method is presented to realize the long-distance and high-precision positioning of sound sources in media. Firstly, theoretical model of HBT interference positioning is established. Location of the sound source can be acquired by analyzing the correlation function of the output signals. Then, sound source localization under different signal-to-noise ratios (SNR) shows that by this method, the sound source can be accurately found with six sensors (two arrays) even the SNR is low to 0.04. Positioning experiment in air is carried out, and the experimental results show that the sound source can be accurately located at 42 meters, and the positioning error is low to 0.1 meters. Thus the validity and accuracy of the HBT interference space location principle is demonstrated. It provides new ideas for the research of long-range target location in sound propagation media (air, water, etc.).

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Ultrastructural aspects of gymnosperms reproductive organs tissues due to their functional condition

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100083060 ◽

1978 ◽

Vol 36 (2) ◽

pp. 440-441

Author(s):

G. M. Kozubov

Keyword(s):

Metabolic Activity ◽

Functional Condition ◽

Reproductive Organs ◽

Considerable Change ◽

Complicated Structure ◽

Tetrad Stage ◽

Ubisch Bodies ◽

Similar Organization ◽

Female Reproductive Organs ◽

High Metabolic Activity

The ultrastructure of reproductive organs of pine, spruce, larch and ginkgo was investigated. It was found that the male reproductive organs possess similar organization. The most considerable change in the ultrastructure of the microsporocytes occur in meiosis. Sporoderm is being laid at the late tetrad stage. The cells of the male gameto-phyte are distinguished according to the metabolic activity of the or- ganells. They are most weakly developed in the spermiogenic cell. Ta-petum of the gymnosperms is of the periplasmodic - secretorial type. The Ubisch bodies which possess similar structure in the types investigated but are specific in details in different species are produced in tapetum.Parietal and subepidermal layers are distinguished for their high metabolic activity and are capable of the autonomous photosynthesis. Female reproductive organs differ more greatly in their struture and have the most complicated structure in primitive groups. On the first stages of their formation the inner cells of nucellus are transformed into the nucellar tapetum in which the structures similar to the Ubisch bodies taking part in the formation of the sporoderm of female gametophyte have been found.

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The Fine Structure of Phloem Cells

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100119867 ◽

1985 ◽

Vol 43 ◽

pp. 632-635

Author(s):

James Cronshaw

Keyword(s):

Structural Studies ◽

High Concentration ◽

Long Distance ◽

Phloem Tissue ◽

Sieve Elements ◽

Long Distance Transport ◽

P Protein ◽

Companion Cells ◽

Electron Microscopical ◽

Distance Transport

Long distance transport in plants takes place in phloem tissue which has characteristic cells, the sieve elements. At maturity these cells have sieve areas in their end walls with specialized perforations. They are associated with companion cells, parenchyma cells, and in some species, with transfer cells. The protoplast of the functioning sieve element contains a high concentration of sugar, and consequently a high hydrostatic pressure, which makes it extremely difficult to fix mature sieve elements for electron microscopical observation without the formation of surge artifacts. Despite many structural studies which have attempted to prevent surge artifacts, several features of mature sieve elements, such as the distribution of P-protein and the nature of the contents of the sieve area pores, remain controversial.

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Popliteal entrapment syndrome and age

VASA ◽

10.1024/0301-1526/a000201 ◽

2012 ◽

Vol 41 (4) ◽

pp. 262-268 ◽

Cited By ~ 3

Author(s):

Schweizer ◽

Hügli ◽

Koella ◽

Jeanneret

Keyword(s):

Risk Factors ◽

Leg Pain ◽

Walking Distance ◽

Therapeutic Approaches ◽

Long Distance ◽

Entrapment Syndrome ◽

Long Distance Running ◽

Popliteal Entrapment ◽

Popliteal Entrapment Syndrome ◽

Atherosclerotic Risk Factors

On the occasion of diagnosing a popliteal entrapment syndrome in a 59-year old man with no cardiovascular risk factors, who developed acute ischemic leg pain during long distance running, we give an overview on this entity with emphasis on patientsage. The different types of the popliteal artery compression syndrome are summarized. The diagnostic and therapeutic approaches are discussed. The most important clinical sign of a popliteal entrapment syndrome is the lack of atherosclerotic risk factors in patients with limited walking distance. Not only in young athletes but also in patients more than 50 years old the popliteal entrapment syndrome has to be taken into account.

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Attachment Styles, Physical Proximity, and Relational Satisfaction

Aviation Psychology and Applied Human Factors ◽

10.1027/2192-0923/a000062 ◽

2014 ◽

Vol 4 (2) ◽

pp. 106-112

Author(s):

Anita Shrivastava ◽

Andrea Burianova

Keyword(s):

Attachment Styles ◽

Romantic Relationship ◽

Distinct Type ◽

Relational Satisfaction ◽

Long Distance ◽

Avoidant Attachment ◽

Geographic Separation ◽

Relationship Of ◽

Attachment Dimensions

This study aimed to explore the relationships between attachment styles, proximity, and relational satisfaction. This was achieved by assessing a distinct type of long distance romantic relationship of flying crews, compared with proximal (non-flying crew) romantic relationships. The responses of 139 expatriate professionals revealed significant associations between proximity and anxious and avoidant attachment dimensions. The role of the avoidant dimension in comparison with that of the anxious dimension was found to be a significant predictor of relational satisfaction. This study contributes significantly toward addressing the role of proximity and attachment in relational satisfaction in a new context of geographic separation.

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