scholarly journals The Use of Sensors for Monitoring the Feeding Process and Adjusting the Feed Supply Velocity in Fish Farms

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Lorena Parra ◽  
Laura García ◽  
Sandra Sendra ◽  
Jaime Lloret

Aquaculture is a growing industry, and its sustainability is crucial. One of its major environmental impacts is the uneaten feed that pollutes the water. To minimize the uneaten feed, many systems have been developed. Nevertheless, current systems can be improved by considering the fish position in the tank and the falling feed. In this paper, we propose a system based on fish presence sensors set at different tank heights and a feed detection sensor located in the drainage tubes. The fish presence sensor is based on light-dependent resistor (LDR). The calibration of these sensors is shown. When the output voltage is higher than 1.467 V, we can consider that fish are present. On the other side, the falling feed sensor is based on a CMOS sensor. The calibration process is performed with 40 pictures. The summation of pixels, with brightness value between 0 and 15 in the blue histogram, is used as an indicator of feed presence. If this value is higher than 520 pixels, we can consider that there is feed in the picture. Moreover, a verification process of both sensors is done. The results of the verification confirm the calibration. Finally, the operation of the system is shown.

2015 ◽  
Vol 1782 ◽  
pp. 1-8
Author(s):  
Ning-Qin Deng ◽  
He Tian ◽  
Qing-Tang Xue ◽  
Zhe Wang ◽  
Hai-Ming Zhao ◽  
...  

ABSTRACTNanogenerators (NGs) have great potential to solve the problems of energy depletion and environmental pollution. Here, two types of flexible nanogenerators (FNGs) based on graphene oxide (GO) and multiwall carbon nanotubes (MW-CNTs) are presented. The peak output voltage and current of GO based FNG reached up to 2 V and 30 nA, respectively, under 15 N force at 1 Hz. Moreover, the output voltage could be improved to 34.4 V when the frequency was increased to 10 Hz. It was also found the output voltage increased from 0.1 V to 2.0 V using a released GO structure. The other FNG was made by MW-CNTs mixed with ZnO nanoparticles (NPs). Its output voltage and power reached up to 7.5 V and 18.75 mW, respectively, which is much larger than that of bare ZnO based FNG. Furthermore, a peak voltage of 30 V could be gained by stamping one’s foot on the FNG. Finally, a modified NG was fabricated using four springs and two flexible layers. As a result, the voltage and power reached up to 9 V and 27mW, respectively. These works may bring out broad applications in energy harvesting.


Author(s):  
David M. Kaplan

Environmental philosophy and philosophy of technology have a lot in common. Both fields explore the positive and negative aspects of human modifications of the world. Both question the limits of technology in relation to natural environments, animals, plants, and food. Both examine if human making and doing is compatible with nature or wholly different from it. And both examine the difference between what is considered to be natural and artificial. Technology and the environment further intersect in a number of issues, such as climate change, sustainability, geo-engineering, and agriculture. The reason for the overlap is fundamental: Environmental issues inevitably involve technology, and technologies inevitably have environmental impacts. Technology and the environment are like two sides of the same coin: Each is fully understood only in relation to the other. Yet, despite the ample overlap of questions concerning technology and the environment, the two philosophical fields have developed in relative isolation from each other. Even when philosophers in each field address themselves to similar concerns, the research tends to be parallel rather than intersecting, and the literatures remain foreign to one another. These divergent paths are unfortunate. Philosophers from each field have a lot to contribute to the other....


2020 ◽  
Vol 12 (21) ◽  
pp. 9151
Author(s):  
Kirsi Laitala ◽  
Ingun Grimstad Klepp

Increasing the length of clothing lifespans is crucial for reducing the total environmental impacts. This article discusses which factors contribute to the length of garment lifespans by studying how long garments are used, how many times they are worn, and by how many users. The analysis is based on quantitative wardrobe survey data from China, Germany, Japan, the UK, and the USA. Variables were divided into four blocks related respectively to the garment, user, garment use, and clothing practices, and used in two hierarchical multiple regressions and two binary logistic regressions. The models explain between 11% and 43% of the variation in clothing lifespans. The garment use block was most indicative for the number of wears, while garment related properties contribute most to variation in the number of users. For lifespans measured in years, all four aspects were almost equally important. Some aspects that affect the lifespans of clothing cannot be easily changed (e.g., the consumer’s income, nationality, and age) but they can be used to identify where different measures can have the largest benefits. Several of the other conditions that affect lifespans can be changed (e.g., garment price and attitudes towards fashion) through quality management, marketing strategies, information, and improved consumer policies.


Author(s):  
Øyvind Pharo Hanisch

Direct Electric Heating (DEH) is an increasingly attractive method for flow assurance that has been in use for more than 15 years. All current systems in operation consist of a single flowline or have subsea architecture such that interaction between systems as well as components in the proximity is limited. DEH is selected as flow assurance for two ongoing field developments where the layout is such that there will be interaction with other subsea architecture. One system has numerous flowline systems in close interaction and the other has unfavorable crossing. This paper presents some of the design aspects which do arise for fields where the flowlines are in close proximity to each other. The paper also discusses how to handle interference with existing infrastructure when installing DEH in a complex field layout. The aspects studied are effect on power rating, ac corrosion and thermal rating of cables and flowlines.


2019 ◽  
Vol 11 (13) ◽  
pp. 3523 ◽  
Author(s):  
Benjamín García García ◽  
Caridad Rosique Jiménez ◽  
Felipe Aguado-Giménez ◽  
José García García

Equations were developed through multiple regression analysis (MRA) to explain the variability of potential environmental impacts (PEIs) estimated by life cycle assessment (LCA). The case studied refers to the production of seabass in basic offshore fish farms. Contribution analysis showed that the components of the system which most influence the potential environmental impacts are the feed (54% of the overall impact) and the fuel consumed by vessels operating in the farm (23%). Feed and fuel varied widely from one fish farm to another due to different factors, such as the efficiency of the feeding system used in each of them, or the distance from the harbor to the farm. Therefore, a number of scenarios (13) were simulated with different values of both factors and the results of the PEI were fitted by MRA to the model: PEI = a + b × Feed + c × Fuel. For all the PEIs, the regression coefficients were significant (p < 0.05) and R2 was 1. These equations allow us to estimate simply and quickly very different scenarios that reflect the reality of different farms at the present time, but also future scenarios based on the implementation of technologies that will decrease both feed and fuel consumption.


2015 ◽  
Vol 740 ◽  
pp. 261-264
Author(s):  
Sheng Zhang ◽  
Pei Zheng Li ◽  
Zhi Wei Chen

As one of the most important parameters of Direct Current (DC) power supply, Load regulation determines the performance of whole system. In this paper, the internal structure as well as performance parameters of LM2577 boosting converter were deeply investigated and based on this investigation we proposed two new methods of improving its Load Regulation. One method (method 1) is to replace the resistor connected to the feedback pin of LM2577 with a programmable potentiometer and sample the variation of output voltage using an AD converter. The potentiometer is adjusted under the control of feedback algorithm to keep the output voltage stable, thus the load regulation enhanced. In the other method (method 2), the feedback pin of LM2577 is connected to an adder to stabilize the output voltage of DC power supply and increase the load regulation. A voltage divider made up of resistors divides the output voltage and provide the divided voltage to one input of the adder. The other adder input comes from DA converter controlled by microcontroller. To reduce the adjust time and increase the efficiency, PID algorithm is applied in the software part of the system. We use 12-bit AD (ADS1115), 12-bit DA (TLV 5638) and 10-bit programmable potentiometer (AD5293) to test the methods above under the condition of 5V input voltage and 600mA load current. When output is set to 7V, the load regulation is improved from 1.043%, the rate from application circuit in LM2577’s Datasheet, to 0.700% and 0.042% by applying the first and second method, respectively. When output voltage equals 12V, the improvement is from 0.658% to 0.008% and 0.008%. Meanwhile, the method 2 suppresses output voltage ripple to be less than 10mV.


2011 ◽  
Vol 255-260 ◽  
pp. 2192-2196
Author(s):  
Cheng Yu Hu ◽  
Peng Tao Liu

The ring signature can guarantee the signer’s anonymity. Most proposed ring signature schemes have two problems: One is that the size of ring signature depends linearly on the ring size, and the other is that the signer can shift the blame to victims because of the anonymity. Some authors have studied the constant-size ring signature and deniable ring signature to solve these two problems. This paper shows that an identity-based ring signature scheme with constant size has some security problems by using an insecure accumulator and its verification process does not include the message m. Then we combine the concepts of “constant-size” and “deniable” to form an id-based deniable ring signature with constant-size signature. The new scheme with constant-size signature length is proposed based on an improved accumulator from bilinear pairings and it solves the problem of anonymity abuse.


2018 ◽  
Author(s):  
Tom M. Loughin ◽  
Stephen N. Bennett ◽  
Nicolaas W. Bouwes

AbstractBefore-after-control-impact (BACI) experimental designs are commonly used in large-scale experiments to test for environmental impacts. However, high natural variability of environmental conditions and populations, and low replication in both treatment and control areas in time and space hampers detection of responses. We compare the power of two asymmetric BACI (aBACI) designs to two staircase designs for detecting changes in juvenile steelhead (Oncorhynchus mykiss) abundance associated with a watershed-scale stream restoration experiment. We performed a simulation study to estimate the effect of a 25% increase in steelhead abundance using spatial and temporal estimates of variance from an ongoing study, and determined the power of each design. Experimental designs were then applied to three streams and each stream was composed of three 4 km long sections. We compared the power of a single treatment section in one stream (BACI-1), three simultaneous treatments of all sections in one stream (BACI-3), three sequential treatments in one stream (STAIRCASE-1), and three sequential treatments in one section in each stream (STAIRCASE-3). All designs had ≥ 94% power to detect a 25% increase in abundance assuming average variance. Under worst-case variance (i.e., upper 95% confidence limits of historical variance estimates), the STAIRCASE-3 design outperformed the BACI-1, BACI-3, and STAIRCASE-1 designs (i.e., 77%, 41%, 8%, and 33% power respectively). All the designs estimated the effect of the simulated 25% abundance increase, but the length of the confidence interval was much shorter for the STAIRCASE-3 design compared to the other designs, which had confidence intervals 58-596% longer. The STAIRCASE-3 design continued to have high power (88%) to detect a 10% change in abundance, but the power of the other designs was much lower (range 34-56%). Our study demonstrates that staircase designs can have significant advantages over BACI designs and therefore should be more widely used for testing environmental impacts.


2019 ◽  
Vol 3 (7) ◽  
pp. 9
Author(s):  
Ana Cristina Pereira Lage

Pretendo analisar um documento que retrata os anos iniciais da Casa de Oração do Vale de Lágrimas, uma instituição educativa feminina que existiu próxima à Vila de Minas Novas, na Capitania de Minas Gerais, no século XVIII. O documento analisado é considerado, até então, como o mais antigo da referida instituição: um ofício do Arcebispo da Bahia, D. José Botelho de Matos, enviado para Diogo de Mendonça Corte Real, datado de 1754. Neste ofício, o Arcebispo solicita a verificação da existência de um Recolhimento feminino no sertão da Capitania de Minas Gerais. No processo de verificação é possível encontrar informações acerca da primeira Regente da instituição, das demais habitantes da Casa e das práticas educativas desenvolvidas na instituição, bem como alguns detalhes da habitação, da religiosidade e do apoio da população local à sua manutenção. Observa-se que as práticas educativas tinham tanto um caráter devocional, como também preparavam as mulheres para o trabalho doméstico e o aprendizado da escrita e da leitura. Encontramos ainda as manobras discursivas da Regente, dos padres e da população local para informar que a instituição não era um Recolhimento e, assim, não passar para a supervisão do arcebispado baiano. O documento é compreendido enquanto uma representação de um determinado grupo com a intencionalidade de enganar o arcebispo e se manter distante das normas que mudariam o funcionamento da instituição.* * *I intend to analyze a document which depicts the initial years of the Casa de Oração do Vale de Lágrimas, an institution for women's education that existed next to the Vila de Minas Novas, in the Captaincy of Minas Gerais, during the XVIII century. The analyzed document is considered, until now, as the oldest on the institution: a craft of the Archbishop of Bahia, Mr. José Botelho de Matos, sent to Diogo de Mendonça Corte Real, dated 1754. In this craft, the Archbishop requests to verify the existence of a female safe house in the backcountry of the Captaincy of Minas Gerais. Over this verification process is possible to find information about the first Director from the institution, the other residents and their educational practices developed there, as well as some details of housing, religiousness e the support of the local population for its maintenance. It is observed that educational practices had both a devotional feature, and also prepared women for housework and learning to write and read. We even found the discursive maneuvers of the Director, the priests and the local population to inform that the institution was not a safe house and, therefore, do not pass the supervision to the archbishopric of Bahia. The document is understood as a representation of a particular group with the intend to deceive the archbishop and to keep distant from the norms that would change the behavior of the institution.


2019 ◽  
Vol 12 (6) ◽  
pp. 1260-1287
Author(s):  
R. T. CECEL ◽  
P. C. R. A. ABRÃO ◽  
F. A. CARDOSO ◽  
V. M. JOHN

Abstract The optimum content of ether polycarboxylate-based superplasticizer, determined by rotational rheometry, and its effects on the environmental impacts of concretes were studied for cement and limestone filler. To assess the consistency and water reduction, flow-table tests were performed. Then, cement content reduction and binder and carbon intensity indexes were determined through estimation based on theoretical concretes. The evaluated pure and blended cements present significant variability of the optimum consumption of the admixture. The fillers consumed less superplasticizer per area than the other materials and compositions with fillers allowed for greater reduction of water content. The mixtures with superplasticizer presented lower cement rate and binder and carbon intensity indexes. The usage of this type of admixture in optimal content can reduce environment impacts, according to the parameters analyzed.


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