Figure 1. Model of the experimental setup in experiment (a). Figure 2. Data from the force plate, force versus time. Impact on small area (left) and large area (right). Note that the maximal force is approximately twice as large for impacts on the large area, and that the duration is only half as long.

2005 ◽  
pp. 88-91
2019 ◽  
Vol 19(34) (2) ◽  
pp. 65-76
Author(s):  
Sylwia Kierczyńska

The aim of the study was to examine the changes in production and export of raspberries and sour cherries, which are the domain of Polish production on the international markets, in the countries of Eastern and Southern Europe during the 2006-2017. There was used data from Faostat database for the analysis of fruit production, and from Comtrade database for the analysis of export volume. Study points to the development of production and an increase in the export of raspberries in countries with a smaller area of cultivation of this fruit crops and stability in countries with a large area of crops of raspberries. In the case of sour cherries, in most countries, both large and small area plantings, production potential, and volume of production of fruit of this species declined. The export of sour cherries increased particularly from countries with less potential in the production of sour cherries. The development of the production and export of raspberries from countries with lower production capacity may in the future be competition for Poland on the international markets.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
G. Panzeri ◽  
M. Cristina ◽  
M. S. Jagadeesh ◽  
G. Bussetti ◽  
L. Magagnin

Abstract In this work, a three-layered heterostructure Cu2O/CuO/CuS was obtained through a low-cost and large-area fabrication route comprising electrodeposition, thermal oxidation, and reactive annealing in a sulfur atmosphere. Morphological, microstructural, and compositional analysis (AFM, SEM, XRD, EDS, XPS) were carried out to highlight the surface modification of cuprous oxide film after oxidation and subsequent sulfurization. Impedance, voltammetric, and amperometric photoelectrochemical tests were performed on Cu2O, Cu2O/CuO, and Cu2O/CuO/CuS photocathodes in a sodium sulfate solution (pH 5), under 100 mW cm−2 AM 1.5 G illumination. A progressive improvement in terms of photocurrent and stability was observed after oxidation and sulfurization treatments, reaching a maximum of − 1.38 mA cm−2 at 0 V versus RHE for the CuS-modified Cu2O/CuO electrode, corresponding to a ~ 30% improvement. The feasibility of the proposed method was demonstrated through the fabrication of a large area photoelectrode of 10 cm2, showing no significant differences in characteristics if compared to a small area photoelectrode of 1 cm2.


Nanoscale ◽  
2021 ◽  
Author(s):  
Jiurong Li ◽  
Haiguang Zhao ◽  
Xiujian Zhao ◽  
Xiao Gong

Luminescent solar concentrators (LSCs) can collect solar light from a large area and concentrate it to their small-area edges mounted with solar cells for efficient solar-to-electricity conversion. Thus, LSCs show...


1991 ◽  
Vol 219 ◽  
Author(s):  
Murray S. Bennett ◽  
A. Catalano ◽  
J. Newton ◽  
C. Poplawski ◽  
R. Arya ◽  
...  

ABSTRACTThree junction a-Si based photovoltaic modules have been made using a design which provides high initial efficiency and good resistance to photodegradation. The cells have a Si/Si/SiGe configuration in which the i-layer in the middle junction is 4000Å thick. The most efficient module measured to date has an aperture area efficiency of 9.82%. This design will limit light-induced efficiency losses to 15% or less, based on small area results, however defect related problems have increased this value to 17 – 23%. Preliminary data on the effect of shunts on stability is presented. We discuss various concerns related to large area deposition and scale-up.


2021 ◽  
Vol 8 ◽  
pp. 13
Author(s):  
Xu Chen ◽  
Yuqian Wang ◽  
Zhiwei Guo ◽  
Xian Wu ◽  
Fengqing Yang ◽  
...  

The magnetic shield plays an important role in magnetic near-field control. However, the requirements of efficiency, ultra thinness, lightness and cheapness are still the challenges. Here, we firstly propose a composite metamaterial in which the mu-near-zero media is covered with a ferrite slab. We verify that this structure can enhance the shielding effectiveness (SE) in a small area. Furthermore, we optimize the magnetic path by changing the bulk ferrite slab into a patterned slab. In this way, significant SE enhancement can be achieved in a large area. Experimental results show that the maximum SE of the composite metamaterial with a patterned ferrite is 20.56 dB, which is nearly 19 dB higher than that of a single ferrite slab with the same thickness of the composite metamaterial. The results on the composite metamaterial would be very useful in the applications involving magnetic shielding.


2016 ◽  
Vol 6 (2) ◽  
pp. 460-464 ◽  
Author(s):  
Chloe A. M. Fabien ◽  
Aymeric Maros ◽  
Christiana B. Honsberg ◽  
William Alan Doolittle

Author(s):  
Dana M. Lis ◽  
Matthew Jordan ◽  
Timothy Lipuma ◽  
Tayler Smith ◽  
Karine Schaal ◽  
...  

Background: Exercise and vitamin C-enriched collagen supplementation increase collagen synthesis, potentially increasing matrix density, stiffness, and force transfer. Purpose: To determine whether vitamin C-enriched collagen (hydrolyzed collagen [HC] + C) supplementation improves rate of force development (RFD) alongside a strength training program. Methods: Using a double-blinded parallel design, over 3 weeks, healthy male athletes (n = 50, 18–25 years) were randomly assigned to the intervention (HC + C; 20 g HC + 50 mg vitamin C) or placebo (20 g maltodextrin). Supplements were ingested daily 60 min prior to training. Athletes completed the same targeted maximal muscle power training program. Maximal isometric squats, countermovement jumps, and squat jumps were performed on a force plate at the same time each testing day (baseline, Tests 1, 2, and 3) to measure RFD and maximal force development. Mixed-model analysis of variance compared performance variables across the study timeline, whereas t tests were used to compare the change between baseline and Test 3. Results: Over 3 weeks, maximal RFD in the HC + C group returned to baseline, whereas the placebo group remained depressed (p = .18). While both groups showed a decrease in RFD through Test 2, only the treatment group recovered RFD to baseline by Test 3 (p = .036). In the HC + C group, change in countermovement jumps eccentric deceleration impulse (p = .008) and eccentric deceleration RFD (p = .04) was improved. A strong trend was observed for lower limb stiffness assessed in the countermovement jumps (p = .08). No difference was observed in maximal force or squat jump parameters. Conclusion: The HC + C supplementation improved RFD in the squat and countermovement jump alongside training.


2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Fu Yang ◽  
Yuting Huang ◽  
Yaowen Li ◽  
Yongfang Li

AbstractTwo major challenges need to be overcome to bridge the efficiency gap between small-area rigid organic solar cells (OSCs) and large-area flexible devices: the first challenge lies in preparing high-quality flexible transparent electrodes with low resistance, high transparency, smooth surface, and superior mechanical properties. Second, the scalable fabrication of thickness-insensitive photoactive layers with low-cost materials is also an essential task. In this review, recent progress and challenges of flexible large-area OSCs are summarized and analyzed. Based on our analysis, strategies and opportunities are proposed to promote the development of stable and efficient flexible large-area OSCs.


Author(s):  
Marta Guth ◽  
Maryla Bieniek-Majka ◽  
Silvia Maican

The purpose of the article was to indicate selected distribution channels in groups and organizations of fruit and vegetable producers in countries with different agrarian structures and cultures of horizontal organization, as well as identify differences in preferred distribution channels. Based on the literature review, changes in the supply chain of agri-food products were presented and the growing importance of retail chains was pointed out. Using the data obtained from the European Commission, the weight of individual distribution channels was presented, and by Ward agglomeration cluster analysis using Euclidean distances, 3 disjointed clusters of countries with different characteristics of fruit and vegetable producer groups/organizations were selected. The first cluster consisted of few producer groups/organizations from Great Britain, Denmark and Romania, whose members engaged in a relatively large area of land and dedicated (65%) their production to retail chains, thus obtaining, on average, higher effects (measured by sales value) attributable to both the group/organization and hectare of land. In contrast, the third cluster included producers from countries that are leaders in the production of fruit and vegetables in Europe, that is, from Spain, Italy, France and Poland. What was characteristic for them was that many members possessing a relatively small area of land joined groups/organisations. They dedicated their production (25%) to retail chains, and their advantage, which may affect the largest share of the average value of sales per member, is the processing of raw materials as part of their own operations.


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