Impact and performance of Mediterranean fishing gear by side-scan sonar technology

2012 ◽  
Vol 69 (11) ◽  
pp. 1806-1816 ◽  
Author(s):  
Alessandro Lucchetti ◽  
Antonello Sala
Keyword(s):  
Fishing Gear ◽  
Side Scan Sonar ◽  
Factors Affecting ◽  
Solea Solea ◽  
Wide Range ◽  
Physical Impact ◽  
And Performance ◽  
Benthic Ecosystems ◽  
Management Issues

An innovative approach with side-scan sonar was implemented to observe directly during towing operations the behaviour and the performance of hydraulic dredge, Rapido trawl, and two types of Mediterranean bottom trawls. The innovative aspect of the current paper is that a side-scan sonar was used alongside fishing operations when towing was in progress. Based on available literature, the type and level of the physical impact assessed were used to infer biological and ecological consequences caused by the fishing gear. The sonar used in real time can be applied to a wide range of research and management issues, such as the fishing gear impact on benthic ecosystems and the in situ fishing gear performance. We demonstrated that gear type and rigging, together with environmental conditions, are the main factors affecting the disturbance caused by fishing. Hydraulic dredges scrape the surface of the substratum and dig into it by resuspending large amounts of sediment. Rapido trawls used in muddy areas for common sole (Solea solea) dig deeper into the sediment, making furrows up to 10–13 cm deep. The most evident physical effects of trawling were the furrows produced by the otterboards, while other parts of the trawl created only faint marks.

Uphoff Norman, Priti Ramamurthy, and Roy Steiner. Managing Irrigation: Analysing and Improving the Performance of Bureaucracies. New Delhi/Newbury Park/London: Sage Publications. 1991. Hardbound. Price not given.

1993 ◽  
Vol 32 (2) ◽  
pp. 226-228
Author(s):  
Zakir Hussain
Keyword(s):  
Water Distribution ◽  
Irrigation System ◽  
Irrigation Management ◽  
Performance Criterion ◽  
New Delhi ◽  
Irrigation Performance ◽  
Factors Affecting ◽  
Wide Range ◽  
Resource Mobilisation ◽  
Management Issues

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.

scholarly journals FEEDBACK: DIFFERENT CONCEPTS AND PRACTICES IN A CULTURALLY DIFFERENT LEARNING ENVIRONMENT? STUDENTS’ PERCEPTIONS

2021 ◽  
Vol 71 (5) ◽  
pp. 1693-99
Author(s):  
Ahsan Malik ◽  
Faiza Kiran ◽  
Fareeha Farooq
Keyword(s):  
Learning Environment ◽  
Information Exchange ◽  
Framework Analysis ◽  
Formal Curriculum ◽  
Factors Affecting ◽  
Qualitative Phenomenology ◽  
Wide Range ◽  
Culturally Different ◽  
Dental Curriculum ◽  
And Performance

Objective: To assess students’ perceptions of feedback, regarding its understanding, and practices in a traditional undergraduate dental curriculum in Pakistan, where feedback was not part of a formal curriculum as a structured entity. Study Design: Qualitative-phenomenology. Place and Duration of Study: Rawal Institute of Health Sciences, Islamabad from Dec 2017 to May 2018. Methodology: Purposive sampling was done, and data was gathered using semi-structured, group interview of 16 BDS students. Data was organized using qualitative software package Atlas.ti 8.0 and analyzed using thematic framework analysis. Results: Feedback, though, being practiced by faculty, was not identify as feedback by students. They did not appreciate it as an essential skillset for learning and performance. Though, conceptions of students regarding this phenomenon varied, five emergent themes displayed the essence of the phenomenon in this learning environment: 1) understanding ‘feedback’ through participants’ response, 2) highly variant experiences of information exchange, 3) modes and forms of feedback, 4) factors affecting feedback and 5) methods achieving learning progression. Conclusion: Our students were devoid of formally instituted feedback practices, so they were unable to identify it as ‘feedback’. Wide range of contradictory and many negative experiences of participants indicated that formal training in feedback and its systematic use might improve students’ experiences.Keywords: , , , , ,  .

Design, Characteristics and Performance of Diamond Pad Conditioners

2010 ◽  
Vol 1249 ◽  
Author(s):  
Douglas J. Pysher ◽  
Brian Goers ◽  
John Zabasajja
Keyword(s):  
Performance Metrics ◽  
Chemical Mechanical Planarization ◽  
Spatial Density ◽  
Height Distribution ◽  
Depth Of Penetration ◽  
Factors Affecting ◽  
Wear Rates ◽  
Wide Range ◽  
Design Characteristics ◽  
And Performance

AbstractA wide range of diamond pad conditioner (disk) designs have been characterized and key performance metrics have been collected. Relationships between design characteristics including diamond size and shape, spatial density, and tip height distribution and polishing pad wear rates and pad surface textures have been established for a variety of pads.Estimation of the depth-of-penetration of working diamonds, from used disk analyses, allows meaningful topographic assessments of alternative conditioner designs and predictions of relative performance. An example of an improved conditioner that illustrates this design methodology is given.Conditioner aggressiveness and its decay in various slurries have been measured to assess disk lifetime in Chemical Mechanical Planarization (CMP) processes environments. Key factors affecting disk lifetime are discussed and an improved-lifetime conditioner for use in aggressive slurries will be reviewed.

scholarly journals Multirotor Drone Aerodynamic Interaction Investigation

Drones ◽  
2018 ◽  
Vol 2 (4) ◽  
pp. 43 ◽  
Author(s):  
Dhwanil Shukla ◽  
Narayanan Komerath
Keyword(s):  
Reynolds Number ◽  
High Speed ◽  
Low Reynolds Number ◽  
Performance Measurements ◽  
Factors Affecting ◽  
Wide Range ◽  
Wake Interactions ◽  
Low Reynolds ◽  
And Performance ◽  
Thrust And Torque

Aerodynamic interactions between rotors are important factors affecting the performance of in-plane multirotor Unmanned Air Vehicles (UAVs) or drones, which are the majority of small size UAVs (or mini-drones). Optimal design requires knowledge of the flow features. The low Reynolds number of many UAV rotors raises the question of how these features differ from those expected by traditional analytical methods for rotorcraft. Aerodynamics of a set of side-by-side rotors in hover over a range of rotor separation and Reynolds number is studied using high-speed Stereo Particle Image Velocimetry (SPIV) and performance measurements. The instantaneous and time-averaged SPIV data presented here indicate an increase in inter-rotor wake interactions with decrease in rotor spacing and Reynolds number. A dip in rotor efficiency at small rotor spacing at low Reynolds number is observed through thrust and torque measurements. The basic components of in-plane multirotor wake and velocity profiles are identified and discussed to help generalize the findings to a wide range of drones. However, the data provide confidence in traditional analysis tools, with small modifications.

In-situ electrical-resistivity measurements in the high-voltage electron microscope

1978 ◽  
Vol 36 (1) ◽  
pp. 68-69
Author(s):  
W. E. King
Keyword(s):  
Electrical Resistivity ◽  
Electron Microscope ◽  
High Voltage ◽  
Resistivity Measurements ◽  
Voltage Electron ◽  
High Voltage Electron Microscope ◽  
High Voltage Electron ◽  
Wide Range ◽  
Helium Gas

A side-entry type, helium-temperature specimen stage that has the capability of in-situ electrical-resistivity measurements has been designed and developed for use in the AEI-EM7 1200-kV electron microscope at Argonne National Laboratory. The electrical-resistivity measurements complement the high-voltage electron microscope (HVEM) to yield a unique opportunity to investigate defect production in metals by electron irradiation over a wide range of defect concentrations.A flow cryostat that uses helium gas as a coolant is employed to attain and maintain any specified temperature between 10 and 300 K. The helium gas coolant eliminates the vibrations that arise from boiling liquid helium and the temperature instabilities due to alternating heat-transfer mechanisms in the two-phase temperature regime (4.215 K). Figure 1 shows a schematic view of the liquid/gaseous helium transfer system. A liquid-gas mixture can be used for fast cooldown. The cold tip of the transfer tube is inserted coincident with the tilt axis of the specimen stage, and the end of the coolant flow tube is positioned without contact within the heat exchanger of the copper specimen block (Fig. 2).

Hygienic assessment of learning environment conditions (by the example of higher educational institutions of the city of Ufa)

2020 ◽  
Vol 99 (4) ◽  
pp. 405-411
Author(s):  
Elena Ju. Gorbatkova
Keyword(s):  
Ionizing Radiation ◽  
Educational Institutions ◽  
Higher Educational Institutions ◽  
Factors Affecting ◽  
Republic Of Bashkortostan ◽  
Average Relative Humidity ◽  
Higher Educational ◽  
The Republic ◽  
And Performance ◽  
The City

Introduction. The important factors affecting health and performance of young people are the conditions of education, in particular, a comfortable microclimate in the classrooms of higher educational institutions. Materials and methods. In view of the urgency of this problem, an analysis was made of the microclimate parameters of educational organizations of different profiles (Ufa city, the Republic of Bashkortostan). 294 classrooms were studied in 22 buildings of 4 leading universities in Ufa. A total of 3,822 measurements were taken to determine the parameters of the microclimate. The analysis of ionizing radiation in the aerial environment of classrooms. There was performed determination of radon and its affiliated products content. In order to assess the conditions and lifestyle of students of 4 higher educational institutions of the city of Ufa, we conducted an anonymous survey of 1,820 students of I and IV years of education. Results. The average temperature in the classrooms of all universities studied was 23.9±0.09 C. The average relative humidity in all classrooms was 34.2 ± 0.42%. Analysis of ionizing radiation (radon and its daughter products decay) in the aerial environment of the classrooms and sports halls located in the basement determined that the average annual equivalent equilibrium volumetric activity of the radon daughter products (EROA ± Δ222Rn) ranged from 28 ± 14 to 69 ± 34.5 meter, which meets the requirements established by SanPiN. Conclusion. The hygienic assessment of the microclimate parameters of educational institutions of various profile revealed a number of deviations from the regulated norms. The results indicate the need to control the parameters of the microclimate, both from the administration of universities, and from the professors. According to the results of the study, recommendations were prepared for the management of higher educational institutions in Ufa.

Factors Affecting Molecular Self-Assembly and Its Mechanism

2012 ◽  
Vol 9 (1) ◽  
pp. 43 ◽  
Author(s):  
Hueyling Tan
Keyword(s):  
Self Assembly ◽  
Building Blocks ◽  
Molecular Engineering ◽  
Molecular Structures ◽  
Polymer Science ◽  
New Approach ◽  
Factors Affecting ◽  
Dna Structures ◽  
Self Assembling ◽  
Wide Range

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.

Site specific agricultural soil management with the use of new technologies

2013 ◽  
Vol 16 (1) ◽  
pp. 59-67
Keyword(s):  
New Technologies ◽  
Digital Interface ◽  
Appropriate Treatment ◽  
Wide Range ◽  
Soil Variation ◽  
Soil Information ◽  
Remote Sensing Techniques ◽  
Agricultural Areas

<p>The Soil Science Institute of Thessaloniki produces new digitized Soil Maps that provide a useful electronic database for the spatial representation of the soil variation within a region, based on in situ soil sampling, laboratory analyses, GIS techniques and plant nutrition mathematical models, coupled with the local land cadastre. The novelty of these studies is that local agronomists have immediate access to a wide range of soil information by clicking on a field parcel shown in this digital interface and, therefore, can suggest an appropriate treatment (e.g. liming, manure incorporation, desalination, application of proper type and quantity of fertilizer) depending on the field conditions and cultivated crops. A specific case study is presented in the current work with regards to the construction of the digitized Soil Map of the regional unit of Kastoria. The potential of this map can easily be realized by the fact that the mapping of the physicochemical properties of the soils in this region provided delineation zones for differential fertilization management. An experiment was also conducted using remote sensing techniques for the enhancement of the fertilization advisory software database, which is a component of the digitized map, and the optimization of nitrogen management in agricultural areas.</p>

Business Aviation in Russia: Specific Features and Prospects of Development

2020 ◽  
Vol 26 (1) ◽  
pp. 86-93
Author(s):  
D. V. Slivinsky ◽  
I. A. Fomina ◽  
D. G. Menshikh
Keyword(s):  
Systems Approach ◽  
National Policy ◽  
Civil Aviation ◽  
Economic Growth Rate ◽  
Factors Affecting ◽  
Organization And Management ◽  
Transport Services ◽  
Business Aviation ◽  
Wide Range

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.

Sign in / Sign up

Export Citation Format

Share Document