scholarly journals To minimize foraging time, use high‐efficiency, energy‐expensive search and capture methods when food is abundant but low‐efficiency, low‐cost methods during food shortages

2021 ◽  
Author(s):  
R. Åke Norberg
2013 ◽  
Vol 756-759 ◽  
pp. 574-578 ◽  
Author(s):  
Xue Zhe Li ◽  
Xiao Hui Feng

The gas sealing performance of electronic sphygmomanometer is an important index of its quality control. At present, the gas leak detection of sphygmomanometer is mainly by manual, which has disadvantages of low efficiency and precision, huge impact of human factors and so on. An automatic and high precision gas sealing performance inspection module is proposed in the paper, which solves the problems of pressure calibration and gas leak detection of sphygmomanometer products. The paper also introduces the principle and implementation of system project. The module is designed by STC12C5A single-chip, KPM DC air pump and the pressure sensor of E8CC, which has advantages of high precision, high efficiency, low cost, and flexible operation etc.


Author(s):  
U. Fegade

Solar energy is an attractive renewable energy source across the globe that can help overcome the energy crises and has the ability to replace conventional resources. Hybrid solar cells have higher conversion efficiency. In the current chapter the research related to the carbon nanotubes, organic and inorganic solar cell, dye-sensitized solar cells and tandem solar cells are reviewed. The organic solar cells are most suitable and economic, but it has low efficiency of up to 15%. The inorganic solar cells are very expensive and have high efficiency of up to 46% and are used in space applications. The hybrid solar cell is the third type and the perovskite tandem has already proven to be quite efficient (17%) and low cost, mostly because of the cheap materials that are being used.


2020 ◽  
Vol 8 (5) ◽  
pp. 1666-1672
Author(s):  
Jingwen Yao ◽  
Yuwen Chen ◽  
Yibing Wu ◽  
Xianfeng Qiao ◽  
Dezhi Yang ◽  
...  

All fluorescent white organic light-emitting diodes (WOLEDs) have aroused significant interest owing to the advantages of excellent operational stability, low efficiency roll-off and low cost.


2018 ◽  
Vol 16 (38) ◽  
Author(s):  
Akram N. Mohammed

There is no adopt in the importance of the optical communications in scientific civil and military applications because of it’s simplicity in manufacturing and it's low cost. The method of optical communication depends upon bearing the light beam the translated informations by a method called the light modulation. This method depends upon changing some light properties as frequency, amplitude and pulse duration according to the translating informations. The changes in the first two properties are concerned optically with the analog modulation while the third one concern at most with digital modulation. All past methods are expensive with low efficiency and needs electrical or magnetic fields. In this technique the source of voice used a source of emitting light at the same time. This was done by using a reflecting microphone to reflect the incident laser beam to the receiver which was an photocell which connected to an audio amplifier. The emitting voice was clear without any type of noise with very high efficiency.


Author(s):  
Maithili P ◽  
Kanakaraj J

The power demand is increased day by day and generation of electrical energy from non-renewable sources are not able to meet the demand. An alternate energy sources are the only solution to meet the power demand. The power generation from solar energy with photovoltaic effect is plays a major role. This Solar PV system has low efficiency. The power semiconductor devices and converter circuit along with inductive / magnetic circuit. The Inverter circuit have an influence on photovoltaic power generation to improve the level of output voltage along with efficiency. In this paper a new transformer less DC-AC converter is proposed, and it has high efficiency, requires less cost when compares with conventional inverter with transformer. Transformer less self-commutated photovoltaic inverter is reflected the advantages of central and string inverters. It gives high output power and low-cost converter. These transformer less DC-AC converter is connect with Boost/Buck-Boost converter for the better output. So, this proposed DC-AC converter topology is not required mechanical switching and it is lighter in size. The PV technology has low efficiency and utilize more cost for generation of power. The proposed transformer less PV inverter is the better choice to increase the usefulness and reduce the charge rate of this PV system.


2010 ◽  
Vol 43 ◽  
pp. 5-8
Author(s):  
Xiao Ming Sheng ◽  
Lei Liu ◽  
Yun Qing Xu

Workpiece placing and removing for stretcher operated by hand have low precision, low efficiency and poor security. The workpiece automatic placing and removing manipulator of stretcher driven by pneumatic is introduced in this paper,in which two control methods: electric-pneumantic control and PLC program control are advanced to realize stepless speed regulation, overload protection and to complete complex actions easily. The design shows the advantages such as simple structure, low cost, easy to operate and maintenance, high efficiency and reliability, which can also improve safety, reduce the labor intensity, ensure product quality and process stability.


2018 ◽  
Vol 24 (3) ◽  
pp. 227-234
Author(s):  
Azar Mostoufi ◽  
Neda Bavarsad ◽  
Sahar Aryanfar ◽  
Abbas Akhgari

Background: Antacids are the most commonly used medications for fast symptomatic relief of gastric disorders. Because of adverse effects, low efficiency and the high cost of some chemical antacids, identifying a natural medicine with high efficiency and low cost seems useful. Therefore, the aim of the present study was to prepare antacid tablets from Cuttlefish bone and assessment of its antacid properties. Methods: 24 different formulations of cuttlefish bone were prepared by direct compression using different fillers (starch, cellulose, lactose, and mixture of those) in different ratios of the drug. Characterization of powders and tablets was done on all formulations and marketed dosage forms (calcium carbonate and Al-Mg). Results: Weight uniformity, hardness, and friability of all formulations were in acceptable range. Tablets prepared by calcined cuttlebone disintegrated in longer time due to their higher hardness which were mostly higher than 5 Kg. Also, disintegration time of formulations 50-50 (lower dose of cuttlebone) was less than other tablets (2 minutes or less). Results of antacid capacity showed that formulations 90-10 and 80-20 raise the acidic pH of the medium above 7.5, which were the same as or more than the capacity of the marketed tablets.


2020 ◽  
Vol 4 (4) ◽  
pp. 159-166
Author(s):  
Xin Xu ◽  
Yujin Yuan ◽  
Bihong Feng ◽  
Wei Deng

Abstract Fruits are an essential part of a healthy, balanced diet and it is particularly important for fibre, essential vitamins, and trace elements. Improvement in the quality of fruit and elongation of shelf life are crucial goals for researchers. However, traditional techniques have some drawbacks, such as long period, low efficiency, and difficulty in the modification of target genes, which limit the progress of the study. Recently, the clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 technique was developed and has become the most popular gene-editing technology with high efficiency, simplicity, and low cost. CRISPR/Cas9 technique is widely accepted to analyse gene function and complete genetic modification. This review introduces the latest progress of CRISPR/Cas9 technology in fruit quality improvement. For example, CRISPR/Cas9-mediated targeted mutagenesis of RIPENING INHIBITOR gene (RIN), Lycopene desaturase (PDS), Pectate lyases (PL), SlMYB12, and CLAVATA3 (CLV3) can affect fruit ripening, fruit bioactive compounds, fruit texture, fruit colouration, and fruit size. CRISPR/Cas9-mediated mutagenesis has become an efficient method to modify target genes and improve fruit quality.


Author(s):  
K.M. Hones ◽  
P. Sheldon ◽  
B.G. Yacobi ◽  
A. Mason

There is increasing interest in growing epitaxial GaAs on Si substrates. Such a device structure would allow low-cost substrates to be used for high-efficiency cascade- junction solar cells. However, high-defect densities may result from the large lattice mismatch (∼4%) between the GaAs epilayer and the silicon substrate. These defects can act as nonradiative recombination centers that can degrade the optical and electrical properties of the epitaxially grown GaAs. For this reason, it is important to optimize epilayer growth conditions in order to minimize resulting dislocation densities. The purpose of this paper is to provide an indication of the quality of the epitaxially grown GaAs layers by using transmission electron microscopy (TEM) to examine dislocation type and density as a function of various growth conditions. In this study an intermediate Ge layer was used to avoid nucleation difficulties observed for GaAs growth directly on Si substrates. GaAs/Ge epilayers were grown by molecular beam epitaxy (MBE) on Si substrates in a manner similar to that described previously.


2019 ◽  
Author(s):  
Charlys Bezerra ◽  
Géssica Santos ◽  
Marilia Pupo ◽  
Maria Gomes ◽  
Ronaldo Silva ◽  
...  

<p>Electrochemical oxidation processes are promising solutions for wastewater treatment due to their high efficiency, easy control and versatility. Mixed metal oxides (MMO) anodes are particularly attractive due to their low cost and specific catalytic properties. Here, we propose an innovative thermal decomposition methodology using <a>polyvinyl alcohol (PVA)</a> as a solvent to prepare Ti/RuO<sub>2</sub>–IrO<sub>2</sub> anodes. Comparative anodes were prepared by conventional method employing a polymeric precursor solvent (Pechini method). The calcination temperatures studied were 300, 400 and 500 °C. The physical characterisation of all materials was performed by X-ray diffraction and scanning electron microscopy coupled with energy dispersive spectroscopy, while electrochemical characterisation was done by cyclic voltammetry, accelerated service lifetime and electrochemical impedance spectroscopy. Both RuO<sub>2</sub> and IrO<sub>2</sub> have rutile-type structures for all anodes. Rougher and more compact surfaces are formed for the anodes prepared using PVA. Amongst temperatures studied, 300 °C using PVA as solvent is the most suitable one to produce anodes with expressive increase in voltammetric charge (250%) and accelerated service lifetime (4.3 times longer) besides reducing charge-transfer resistance (8 times lower). Moreover, the electrocatalytic activity of the anodes synthesised with PVA toward the Reactive Blue 21 dye removal in chloride medium (100 % in 30 min) is higher than that prepared by Pechini method (60 min). Additionally, the removal total organic carbon point out improved mineralisation potential of PVA anodes. Finally, this study reports a novel methodology using PVA as solvent to synthesise Ti/RuO<sub>2</sub>–IrO<sub>2</sub> anodes with improved properties that can be further extended to synthesise other MMO compositions.</p>


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