Factors Affecting the Response of Trout to an Electric Field in Fresh and Salt Water

1967 ◽  
Vol 24 (1) ◽  
pp. 191-199 ◽  
Author(s):  
John E. C. Flux

The "minimum response" level of Salmo trutta to an alternating current field increased with angle to the field, temperature, resistivity, and fatigue, with a wide range of individual variation. The drop in potential across the length of a fish ("body-voltage") varies directly with length and is not a constant for the species in either fresh or salt water. Embryo trout show a fully developed response 2 weeks after hatching.

2012 ◽  
Vol 9 (1) ◽  
pp. 43 ◽  
Author(s):  
Hueyling Tan

Molecular self-assembly is ubiquitous in nature and has emerged as a new approach to produce new materials in chemistry, engineering, nanotechnology, polymer science and materials. Molecular self-assembly has been attracting increasing interest from the scientific community in recent years due to its importance in understanding biology and a variety of diseases at the molecular level. In the last few years, considerable advances have been made in the use ofpeptides as building blocks to produce biological materials for wide range of applications, including fabricating novel supra-molecular structures and scaffolding for tissue repair. The study ofbiological self-assembly systems represents a significant advancement in molecular engineering and is a rapidly growing scientific and engineering field that crosses the boundaries ofexisting disciplines. Many self-assembling systems are rangefrom bi- andtri-block copolymers to DNA structures as well as simple and complex proteins andpeptides. The ultimate goal is to harness molecular self-assembly such that design andcontrol ofbottom-up processes is achieved thereby enabling exploitation of structures developed at the meso- and macro-scopic scale for the purposes oflife and non-life science applications. Such aspirations can be achievedthrough understanding thefundamental principles behind the selforganisation and self-synthesis processes exhibited by biological systems.


1993 ◽  
Vol 32 (2) ◽  
pp. 226-228
Author(s):  
Zakir Hussain

The book; under review provides a valuable account of the issues and factors in managing the irrigation system, and presents a lucid and thorough discussion on the performance of the irrigation bureaucracies. It comprises two parts: the first outlines the factors affecting irrigation performance under a wide range of topics in the first five chapters. In Chapter One, the authors have attempted to assess the performance of the irrigation bureaucracies, conceptualise irrigation management issues, and build an empirical base for analysis while drawing upon the experience of ten country cases in Asia, Africa, and Latin America. The Second Chapter focuses on the variations in the management structures identified and the types of irrigation systems; and it defines the variables of the management structures. The activities and objectives of irrigation management are discussed in Chapter Three. The objectives include: greater production and productivity of irrigation projects; improved water distribution; reduction in conflicts; greater resource mobilisation and a sustained system performance. The authors also highlight the performance criterion in this chapter. They identify about six contextual factors which affect the objectives and the performance of irrigation, which are discussed in detail in Chapter Four. In Chapter Five, some organisational variables, which would lead to improvements in irrigation, are examined.


2020 ◽  
Vol 26 (1) ◽  
pp. 86-93
Author(s):  
D. V. Slivinsky ◽  
I. A. Fomina ◽  
D. G. Menshikh

The presented study determines the role of business aviation in the modern economy and examines the specific features of its development in Russia.Aim. The study aims to analyze the development of business aviation in Russia and its correlation with economic development in general.Tasks. The authors determine the benefits of business aviation as a business tool, examine the specific features of the Russian business aviation market and problems of its development, and identify factors that affect the development of business aviation in Russia.Methods. This study uses the methods of comparative and retrospective analysis, cross-country comparison, systems approach, and expert analytics.Results. Business aviation is a new segment of civil aviation for Russia. Therefore, it is advisable to rely on foreign practices in the management of its development. In many countries, business aviation is a separate industry that specializes in providing transport services to a wide range of corporate clients and/or individuals. The development of this industry is associated with the economic growth rate and the development level of the national economy, and also depends on the national institutional specifics. This study describes the specific features of development of business aviation in Russia and problems arising in the organization and management of this type of business.Conclusions. The authors develop a system of factors affecting the development of business aviation in Russia, describe the major problems of this industry, and propose solutions. The results of this study can be used in the development (adjustment) of business aviation development strategies in Russia both at the industrial and corporate level, and in the implementation of the national policy in this field.


2015 ◽  
pp. 758-760
Author(s):  
Romain Delecourt ◽  
Loïc Marsal

Maguin (France) is still active in the application of pulsed electric field (PEF) technology. After having carried out successful tests on a 10 t/h pilot screw-type machine on sugar beet cossettes, a new application system based on a roller technology has been developed. This technology allows a wide range of application due to its flexibility with flowrates and materials. A variety of process schemes are proposed to ensure the best performance of the PEF technology.


2020 ◽  
Author(s):  
Salime Goharinezhad

BACKGROUND World Health Organization declared the vaccine hesitancy as a global public health threat in 2019. Since even a slight reduction in vaccine coverage rates can lead to a decrease in herd immunity, it is imperative to explore the underlying factors affecting vaccine hesitancy. in specific contexts, considering socioeconomic and cultural variation, to ensure interventions targeting hesitancy are well formulated and intervened. OBJECTIVE The main objective of this study is to identify underlying factors affecting vaccine hesitancy in Iran. METHODS A framework qualitative study will be conducted in the west of Tehran province in 2020. Participants in the study will be recruited hesitance-parents who extracted from the SIB system (an electronic health record in Iran) to maximize diversity. Interviews will be analyzed based on ''Determinants of Vaccine Hesitancy Matrix'' which developed by the WHO-SAGE Working Group. RESULTS deep understanding from the context-specific reasons for vaccine hesitancy cause to formulate better strategies to address them. The ultimate goal of this study is to inform future policies to increase the uptake of the vaccine in Iran. CONCLUSIONS This result of study will show variety opinions about vaccination among different types of socioeconomic and demographic households. The wide range of reasons related to vaccine hesitancy imply to more comprehensive, context-specific interventions. Today, the most important intervention issues focus on improving information about effectiveness and safety of vaccines, while other interventions for promoting vaccination is need to addressed.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kai Yan ◽  
Chun-lian Wang ◽  
Steffen Mischke ◽  
Jiu-yi Wang ◽  
Li-jian Shen ◽  
...  

AbstractMajor, trace and rare earth element (REE) geochemistry of the late Cretaceous lower Zhoutian Formation from the Jitai Basin of Southeast China were measured by inductively coupled plasma mass spectrometry (ICP-MS) analysis to infer the provenance of the sediments and to reconstruct the palaeoenvironment and palaeoclimate. The wide range of Sr/Cu ratios point to a fluctuating palaeoclimate, and the negative correlation between the FeO/MnO and Al2O3/MgO ratios and the Sr/Cu ratio indicates that the late Cretaceous climate during the lower Zhoutian Formation in the Jitai Basin can be divided into two parts. The lower part experienced two cooling periods, whilst the upper part was dominated by warm-humid climate. Mostly corresponding trends of the B/Ga, Sr/Ba and Sr/Cu ratios show that the salinity changed consistently with the late Cretaceous climate during the lower Zhoutian Formation in the Jitai Basin. During the lower part, the salinity changed from salt water to fresh/brackish water. In the upper part, water was mainly fresh/brackish, and there were many changes from fresh/brackish water to salt water. The relatively stable Ni/Co, V/Cr, V/(V + Ni) and Ce/Ce* data indicate a long period of oxic conditions. The La-Th-Sc, Th-Sc-Zr/10 and La/Th-Hf data of the silt- and sandstones of the lower Zhoutian Formation show that its provenance was mainly a mixture of felsic upper crust sediments and older sedimentary rocks.


Textiles ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 55-85
Author(s):  
Tufail Hassan ◽  
Hafsa Jamshaid ◽  
Rajesh Mishra ◽  
Muhammad Qamar Khan ◽  
Michal Petru ◽  
...  

Recently, very rapid growth has been observed in the innovations and use of natural-fiber-based materials and composites for acoustic applications due to their environmentally friendly nature, low cost, and good acoustic absorption capability. However, there are still challenges for researchers to improve the mechanical and acoustic properties of natural fiber composites. In contrast, synthetic fiber-based composites have good mechanical properties and can be used in a wide range of structural and automotive applications. This review aims to provide a short overview of the different factors that affect the acoustic properties of natural-fiber-based materials and composites. The various factors that influence acoustic performance are fiber type, fineness, length, orientation, density, volume fraction in the composite, thickness, level of compression, and design. The details of various factors affecting the acoustic behavior of the fiber-based composites are described. Natural-fiber-based composites exhibit relatively good sound absorption capability due to their porous structure. Surface modification by alkali treatment can enhance the sound absorption performance. These materials can be used in buildings and interiors for efficient sound insulation.


Pressure has been used as the principal parameter in calculations of the fundamental vibrational frequencies of spherical drops of radius R , density ρ, and surface tension T carrying a charge Q or uncharged spheroidal drops of axial ratio a / b situated in a uniform electric field of strength E . Freely vibrating charged drops have a frequency f = f 0 ( 1 - Q 2 /16π R 3 T ) ½ , as shown previously by Rayleigh (1882) using energy considerations; f 0 is the vibrational frequency of non-electrified drops (Rayleigh 1879). The fundamental frequency of an uncharged drop in an electric field will decrease with increasing field strength and deformation a / b and will equal zero when E ( R )/ T ) ½ = 1.625 and a / b = 1.86; these critical values correspond to the disintegration conditions derived by Taylor (1964). An interferometric technique involving a laser confirmed the accuracy of the calculations concerned with charged drops. The vibration of water drops of radius around 2 mm was studied over a wide range of temperatures as they fell through electric fields either by suspending them in a vertical wind tunnel or allowing them to fall between a pair of vertical electrodes. Photographic analysis of the vibrations revealed good agreement between theory and experiment over the entire range of conditions studied even though the larger drops were not accurately spheroidal and the amplitude of the vibrations was large.


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