scholarly journals Wettability Increase in Plasma-Treated Agricultural Seeds and Its Relation to Germination Improvement

Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1467
Author(s):  
Matej Holc ◽  
Miran Mozetič ◽  
Nina Recek ◽  
Gregor Primc ◽  
Alenka Vesel ◽  
...  
Keyword(s):  
Power Density ◽  
Treatment Time ◽  
Discharge Power ◽  
Agricultural Practice ◽  
Water Contact ◽  
Gaseous Plasma ◽  
Moderate Power ◽  
Hydrophobic Recovery ◽  
Optimal Values ◽  
Power Densities

The literature on plasma-stimulated modification of seed wettability and germination is reviewed and analyzed. The results reported by different authors are scattered, but there is a positive correlation between the change in the water contact angle and the germination improvement. There is hardly any correlation between the germination and the power density used for sustaining gaseous plasma. The wettability, on the other hand, exhibits optimal values at the power density of roughly 1 W cm−3, but the results differ significantly. In fact, a super hydrophilic surface finish was only reported at such moderate power densities. Both the wettability and germination increase with treatment time, but saturate at a certain level, depending on the discharge power. Unlike for most polymers, the hydrophobic recovery does not appear to be a considerable obstacle, so the plasma treatment may be performed well before sowing, which makes the technique applicable in agricultural practice. The scattering of results indicates that the commonly reported parameters such as the type and mode of discharge, the discharge power or power density, the type of gas and its pressure, the treatment time and the type of the seeds, are not decisive parameters governing wettability and germination. Based on the observations of the reviewing authors, conclusions and scientific challenges in this scientific niche are summarized.

scholarly journals Study on modifying the Au surface by thiol compound for biosensor application

2016 ◽  
Vol 19 (4) ◽  
pp. 178-187
Author(s):  
Khoa Thanh Nhat Phan ◽  
Thanh Trung Nguyen ◽  
Tuan Van Phan ◽  
Binh Van Pham ◽  
Tung Xuan Thanh Pham ◽  
...  
Keyword(s):  
Contact Angle ◽  
Horseradish Peroxidase ◽  
Laser Beam ◽  
Water Contact Angle ◽  
Treatment Time ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Water Contact ◽  
Biosensor Application ◽  
Optimal Values

In cantilever-based biosensor, Au surface plays two essential roles: as a surface to reflect laser beam and as a surface to be modified and thus functionalize the sensor. In this paper, we researched on modifying the Au surface by cysteamine and glutaraldehyde to make it reactive toward amine substances. Cysteamine concentration, cysteamine treatment time and glutaraldehyde treatment time were investigated to find optimal values. The data of chromogenic reaction catalyzed by horseradish peroxidase (HRP) and the data of water contact angle measurement were combined to find the optimal values. The results showed that the modification with 5 mM cysteamine in ethanol for 16 h and glutaraldehyde for 1 h would create the Au surface which can react optimally with amine substances.

scholarly journals Near-field thermophotovoltaics for efficient heat to electricity conversion at high power density

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Rohith Mittapally ◽  
Byungjun Lee ◽  
Linxiao Zhu ◽  
Amin Reihani ◽  
Ju Won Lim ◽  
...  
Keyword(s):  
Power Density ◽  
High Power ◽  
High Efficiency ◽  
Near Field ◽  
Electrical Power ◽  
Photovoltaic Cells ◽  
High Power Density ◽  
Pv Cell ◽  
Electrical Power Output ◽  
Power Densities

AbstractThermophotovoltaic approaches that take advantage of near-field evanescent modes are being actively explored due to their potential for high-power density and high-efficiency energy conversion. However, progress towards functional near-field thermophotovoltaic devices has been limited by challenges in creating thermally robust planar emitters and photovoltaic cells designed for near-field thermal radiation. Here, we demonstrate record power densities of ~5 kW/m2 at an efficiency of 6.8%, where the efficiency of the system is defined as the ratio of the electrical power output of the PV cell to the radiative heat transfer from the emitter to the PV cell. This was accomplished by developing novel emitter devices that can sustain temperatures as high as 1270 K and positioning them into the near-field (<100 nm) of custom-fabricated InGaAs-based thin film photovoltaic cells. In addition to demonstrating efficient heat-to-electricity conversion at high power density, we report the performance of thermophotovoltaic devices across a range of emitter temperatures (~800 K–1270 K) and gap sizes (70 nm–7 µm). The methods and insights achieved in this work represent a critical step towards understanding the fundamental principles of harvesting thermal energy in the near-field.

scholarly journals Power Density Improvement of Piezoelectric Energy Harvesters via a Novel Hybridization Scheme with Electromagnetic Transduction

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 803
Author(s):  
Zhongjie Li ◽  
Chuanfu Xin ◽  
Yan Peng ◽  
Min Wang ◽  
Jun Luo ◽  
...  
Keyword(s):  
Power Density ◽  
Output Power ◽  
Energy Harvester ◽  
Hybrid Energy ◽  
Energy Harvesters ◽  
Piezoelectric Patch ◽  
Piezoelectric Energy ◽  
Electromagnetic Transduction ◽  
Self Powered ◽  
Power Densities

A novel hybridization scheme is proposed with electromagnetic transduction to improve the power density of piezoelectric energy harvester (PEH) in this paper. Based on the basic cantilever piezoelectric energy harvester (BC-PEH) composed of a mass block, a piezoelectric patch, and a cantilever beam, we replaced the mass block by a magnet array and added a coil array to form the hybrid energy harvester. To enhance the output power of the electromagnetic energy harvester (EMEH), we utilized an alternating magnet array. Then, to compare the power density of the hybrid harvester and BC-PEH, the experiments of output power were conducted. According to the experimental results, the power densities of the hybrid harvester and BC-PEH are, respectively, 3.53 mW/cm3 and 5.14 μW/cm3 under the conditions of 18.6 Hz and 0.3 g. Therefore, the power density of the hybrid harvester is 686 times as high as that of the BC-PEH, which verified the power density improvement of PEH via a hybridization scheme with EMEH. Additionally, the hybrid harvester exhibits better performance for charging capacitors, such as charging a 2.2 mF capacitor to 8 V within 17 s. It is of great significance to further develop self-powered devices.

Giant power density produced by PIN–PMN–PT ferroelectric single crystals due to a pressure induced polar-to-nonpolar phase transformation

2021 ◽  
Author(s):  
Sergey I. Shkuratov ◽  
Jason Baird ◽  
Vladimir G. Antipov ◽  
Christopher S. Lynch ◽  
Shujun Zhang ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Energy Storage ◽  
Single Crystals ◽  
Power Density ◽  
Ferroelectric Materials ◽  
Power Supplies ◽  
Energy Storage Devices ◽  
Storage Devices ◽  
New Generation ◽  
Power Densities

The search for ferroelectric materials capable of producing high electric charge and power densities is important for developing a new generation of ultrahigh-power-density ferroelectric energy storage devices and autonomous megawatt power supplies.

Thermal-Aware Partitioning and Encoding of Power-Gated FSM

2019 ◽  
Vol 28 (09) ◽  
pp. 1950144
Author(s):  
Priyanka Choudhury ◽  
Kanchan Manna ◽  
Vivek Rai ◽  
Sambhu Nath Pradhan
Keyword(s):  
Power Density ◽  
Power Dissipation ◽  
Hot Spots ◽  
Cmos Technology ◽  
Absolute Temperature ◽  
Temperature Management ◽  
Average Temperature ◽  
Finite State ◽  
Suitable Area ◽  
Power Densities

Miniaturization and the continued scaling of CMOS technology leads to the high-power dissipation and ever-increasing power densities. One of the major challenges for the designer at all design levels is the temperature management, particularly the local hot spots along with power dissipation. In this work, the controller circuits which are implemented as Finite State Machines (FSMs) are considered for their thermal-aware and power-aware realization. Using Genetic Algorithm (GA), both encoding and bipartitioning of the FSM circuit are implemented to get two subFSMs such that at a particular instant of time, one subFSM is active at a time, whereas the other one is power-gated. Again, thermal-aware realization (in terms of power-density) of this power-gated FSM is done. Therefore, the work concerns with the thermal-aware encoding and partitioning of FSM for its power-gated realization. Average temperature saving obtained in this approach for a set of benchmark circuits over previous works is more than 16%. After getting the final partitioned circuit which is optimized in terms of Area and power-density, thermal analysis of the sunFSMs is performed to get the absolute temperature. As thermal-aware design may increase the area, a suitable area-temperature trade-off is also presented in this paper.

scholarly journals Suppression of Hydrophobic Recovery in Photo-Initiated Chemical Vapor Deposition

Catalysts ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 534
Author(s):  
Alessio Aufoujal ◽  
Ulrich Legrand ◽  
Jean-Luc Meunier ◽  
Jason Robert Tavares
Keyword(s):  
Contact Angle ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Water Contact ◽  
Initiated Chemical Vapor Deposition ◽  
Hydrophobic Recovery ◽  
Topmost Layer ◽  
Nanometric Film ◽  
Polar Functional Groups

Photo-initiated chemical vapor deposition (PICVD) functionalizes carbon nanotube (CNT)-enhanced porous substrates with a highly polar polymeric nanometric film, rendering them super-hydrophilic. Despite its ability to generate fully wettable surfaces at low temperatures and atmospheric pressure, PICVD coatings normally undergo hydrophobic recovery. This is a process by which a percentage of oxygenated functional group diffuse/re-arrange from the top layer of the deposited film towards the bulk of the substrate, taking the induced hydrophilic property of the material with them. Thus, hydrophilicity decreases over time. To address this, a vertical chemical gradient (VCG) can be deposited onto the CNT-substrate. The VCG consists of a first, thicker highly cross-linked layer followed by a second, thinner highly functionalized layer. In this article, we show, through water contact angle and XPS measurements, that the increased cross-linking density of the first layer can reduce the mobility of polar functional groups, forcing them to remain at the topmost layer of the PICVD coating and to suppress hydrophobic recovery. We show that employing a bi-layer VCG suppresses hydrophobic recovery for five days and reduces its effect afterwards (contact angle stabilizes to 42 ± 1° instead of 125 ± 3°).

High Power-Density SiC Converter

2008 ◽  
Vol 600-603 ◽  
pp. 1223-1226 ◽  
Author(s):  
Shin Ichi Kinouchi ◽  
Hiroshi Nakatake ◽  
T. Kitamura ◽  
S. Azuma ◽  
S. Tominaga ◽  
...  
Keyword(s):  
Power Density ◽  
High Power ◽  
Power Loss ◽  
Cooling System ◽  
High Power Density ◽  
Loss Reduction ◽  
Effective Volume ◽  
Similar Rating ◽  
Power Densities ◽  
System Volume

A compact SiC converter having power densities about 9 W/cm3 is designed and fabricated. It is confirmed that the converter operates in a thermally permissive range. The power loss of the module of the converter measured under motor operations is less than 50% of the similar-rating Si module loss. The shrink of the effective volume of DC-link capacitor is necessary to achieve the high power-density SiC converter, in addition to the decrease of the cooling system volume due to the loss reduction caused by SiC devices.

scholarly journals Improved Hydrophobicity and Dimensional Stability of Wood Treated with Paraffin/Acrylate Compound Emulsion through Response Surface Methodology Optimization

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 86 ◽  
Author(s):  
Jun Jiang ◽  
Yupeng Chen ◽  
Jinzhen Cao ◽  
Changtong Mei
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Dimensional Stability ◽  
Treatment Time ◽  
Treated Wood ◽  
Good Prediction ◽  
Water Contact ◽  
Correlation Models ◽  
Acrylate Emulsion ◽  
Emulsion Concentration

Wood treatment was conducted by paraffin/acrylate compound emulsion. Response surface methodology (RSM) was applied for modeling and to determine the relationship between hydrophobicity and influencing factors. The results showed that the paraffin emulsion concentration and acrylate emulsion percentage had significant influences on water absorption (WA) and mass percentage gain (MG). The WA decreased obviously with increasing acrylate emulsion percentage. The correlation models for WA and MG showed a good prediction due to the straight-line distribution in the normal probability plot of residuals. The optimal conditions (5.57% paraffin emulsion concentration, 20% acrylate emulsion percentage, and 10 min treatment time) provided by RSM were acceptable for predicting the MG and WA. Compared to untreated (66°) and paraffin emulsion treated wood (94°), the wood treated by compound emulsion showed the highest water contact angle (133°) and better dimensional stability. This could be ascribed to a synergistic effect (bulking effect and filling effect) provided by paraffin and acrylate, which could form a completely hydrophobic film in wood.

scholarly journals Surface Modification of Polyamides by Gaseous Plasma—Review and Scientific Challenges

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3020
Author(s):  
Gregor Primc
Keyword(s):  
Surface Modification ◽  
Oxygen Concentration ◽  
Treatment Time ◽  
Plasma Reactor ◽  
Prolonged Treatment ◽  
Water Contact ◽  
Static Water ◽  
Nitrogen Concentrations ◽  
Polar Functional Groups ◽  
Almost All

A review of the most significant scientific achievements in the field of surface modification of polyamides by non-equilibrium plasma treatments is presented. Most authors employed atmospheric pressure discharges and reported improved wettability. The super-hydrophilic surface finish was only achieved using a low-pressure plasma reactor and prolonged treatment time, enabling both the nanostructuring and functionalization with polar functional groups. The average increase of the oxygen concentration as probed by XPS was about 10 at%, while the changes in nitrogen concentrations were marginal in almost all cases. The final static water contact angle decreased with the increasing treatment time, and the oxygen concentration decreased with the increasing discharge power. The need for plasma characterization for the interpretation of experimental results is stressed.

CW Argon-ion laser initiated aluminum induced crystallization of amorphous silicon thin films

2004 ◽  
Vol 808 ◽  
Author(s):  
Sampath K. Paduru ◽  
Husam H. Abu-safe ◽  
Hameed A. Naseem ◽  
Adnan Al-Shariah ◽  
William D. Brown
Keyword(s):  
Thin Films ◽  
Amorphous Silicon ◽  
Power Density ◽  
Threshold Power ◽  
Argon Ion Laser ◽  
Ion Laser ◽  
Power Densities ◽  
Argon Ion ◽  
Induced Crystallization ◽  
Aluminum Induced Crystallization

ABSTRACTCW Argon-ion laser initiated aluminum induced crystallization (AIC) of RF magnetron sputtered amorphous silicon (a-Si) thin films has been investigated. It was found that lasers could be effectively used to initiate AIC process at very low threshold power densities. An argon-ion laser (λ=514.5 nm) was used to anneal Al/a-Si/glass structures with varying power densities ranging between 55 and 125 W/cm2 and exposure times ranging from 10 to 120 s. X-ray diffraction analysis showed the resulting films to be polycrystalline. The crystallization rate increased both with power density and exposure time. Environmental scanning electron microscopy (ESEM) analysis showed that the surface features change with increasing power density and irradiation time. A dendritic growth pattern was observed in the initial stages of interaction between the films. A strong crystalline Raman peak at around 520 cm-1 was observed in the Raman spectra of the crystallized samples.

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