scholarly journals Properly Recycled Perlite Saves Money, Does Not Reduce Greenhouse Tomato Yield, and Can Be Reused for Many Years

2005 ◽  
Vol 15 (2) ◽  
pp. 342-345 ◽  
Author(s):  
H.Y. Hanna

A study was conducted to determine if raising tomatoes (Lycopersicon esculentum) in cleaned and disinfected used perlite would be more economical than new perlite and have no negative impact on yield. Cleaning and disinfecting used perlite for recycling saved 56% of the cost to replace the media and reduced salt content to the optimum level recommended for raising container grown plants. Disinfecting used perlite with hot water raised media temperatures above limits necessary to kill several fungi and nematodes. Tomatoes planted in recycled perlite produced greater marketable yield and heavier fruit than those planted in new perlite. Season and year of planting also have significant effects on yield. Used perlite can be cleaned and disinfected as needed and recycled for many years because it is not organic in nature and physically and chemically stable.

2010 ◽  
Vol 20 (4) ◽  
pp. 746-750 ◽  
Author(s):  
Hanna Y. Hanna

Planting greenhouse tomatoes (Solanum lycopersicum) in the same perlite more than once without reconditioning to restore medium loose structure, desalination to remove excess salt, and disinfection to guard against pest contamination is risky, and replacing the perlite to produce every new crop is costly. Reconditioning and treating perlite with hot water at a minimum cost provides a favorable solution for both problems and saves natural resources. A study was conducted in a 30 × 96-ft greenhouse in Spring 2007, 2008, and 2009 (January–July) to evaluate three methods for perlite recycling cost, desalination efficiency, and effects on tomato yield at three or four fruit per cluster. Each recycling method consisted of two components: the reconditioning action and the hot water treatment. The three recycling methods included no stir/sift then disinfect, stir then disinfect, and sift then disinfect. Perlite recycled with the no stir/sift then disinfect method was not reconditioned before the hot water treatment. Instead, it was agitated with a nozzle mounted on a pressure washer wand during the hot water treatment. Perlite recycled with the stir then disinfect method was reconditioned first with an auger mounted on an electric drill and then treated with hot water. Perlite recycled with the sift then disinfect method was reconditioned first by sifting the perlite with a homemade apparatus and was then treated with hot water. Recycling perlite with the no stir/sift then disinfect method reduced labor input by 49% and 81% compared with the stir then disinfect and the sift then disinfect methods, respectively. The no stir/sift then disinfect method reduced recycling cost by 22% and 50% compared with the other two methods, respectively. Perlite that was not reconditioned (no stir/sift) had higher nitrate-nitrogen (NO3-N) before hot water treatment than the stirred perlite and equal NO3-N to the sifted perlite. Hot water treatment significantly reduced medium electrical conductivity, NO3-N, potassium, and sodium. Tomatoes grown in perlite recycled with any of the three methods produced similar marketable and cull yields and fruit weight. Pruning fruit to three per cluster increased marketable yield, fruit weight, and reduced cull yield. There was no significant recycling method × cluster pruning interaction for yield components, indicating that all recycling methods had similar effects on tomato yield at three or four fruit per cluster. We conclude that the no stir/sift then disinfect method is less time consuming, more economical, and has no negative impact on yield. Tomatoes grown with three fruit per cluster in perlite recycled with any of the three methods produced greater marketable yield, less cull yield, and heavier fruit than tomatoes grown with four fruit per cluster.


2002 ◽  
Vol 82 (4) ◽  
pp. 771-780 ◽  
Author(s):  
X. Hao ◽  
A. P. Papadopoulos

Two full spring season tomato crops (Lycopersicon esculentum Mill. “Trust”) were grown in an open rockwool system with standard rockwool feeding formulae (O-R; conventional method), and in closed rockwool systems with standard rockwool (C-R) or Nutrient Film Technique (C-NFT) feeding formulae (modified in 1997) in 1996 and 1997 to examine the feasibility of a fully closed rockwool production system with appropriate feeding formulae. The closed rockwool system with optimized feeding formulae achieved high marketable yield, similar to that of the open rockwool system. There were no differences in early plant growth, plant biomass or biomass partitioning, and in total fruit yield, size and grades except for the closed rockwool system with the standard rockwool feeding formulae (C-R), which had lower yield than C-NFT in the last month of harvest in 1996. The photosynthesis of old foliage was higher and the root systems at the end of the experiments were rated healthier in plants grown in the closed (C-R and C-NFT) systems than in plants grown in the open (O-R) system. Over 30% of water and fertilizer was saved with the closed systems in comparison to the conventional open system. These results demonstrated that closed rockwool systems with optimized nutrient feedings are economically and environmentally sound alternative methods for greenhouse tomato production in Ontario. Key words: Lycopersicon esculentum, tomato, yield, recycling, rockwool, greenhouse


2021 ◽  
Vol 43 (4) ◽  
pp. 17-24
Author(s):  
A. A. Dolinsky ◽  
O. M. Obodovych ◽  
V.V. Sydorenko ◽  
A.Y. Lymar

Thousands of medium and low steam boilers and hot water boilers operate in the country's industry, municipal energy and agriculture. Their reliable operation is largely determined by the maintenance of a rational water-chemical regime. The main problems of source water are the presence of dissolved oxygen, iron ions, salts of calcium, and magnesium. The aim of the work is to analyze the existing technologies and equipment for water treatment for different types of boilers. Determination of physicochemical parameters and requirements for source and prepared water. Presentation of new multi-purpose energy-efficient and resource-saving water treatment equipment. The article considers the negative impact of dissolved iron, hardness salts, dissolved gases present in the feed water on the operation of boiler equipment. The main requirements for feed water in terms of hardness, the content of dissolved oxygen, and oils for steam and hot water boilers are given. The mechanism of scale formation is given. The main existing methods of feed water treatment are considered, namely softening on Na-cation exchange resin, liming, softening, and reduction of total salt content on reverse osmosis units, softening, and reduction of total salt content by the sequential passage of water through H, OH-ion exchange filters. A multi-purpose aeration-oxidation setup of rotor type (AORT) is presented, which implements the method of discrete-pulse energy input, on which it is possible to carry out operations to remove iron, manganese, hardness salts, increase pH and degassing from water.


2009 ◽  
Vol 19 (2) ◽  
pp. 395-399 ◽  
Author(s):  
Hanna Y. Hanna

Cultivars and growing media are important components of a successful greenhouse tomato (Solanum lycopersicum) operation. Two studies were conducted simultaneously and independently in two 30 × 96-ft greenhouses in Spring 2006 and 2007 (January–July) to assist producers in selecting appropriate cultivars and reducing production cost. The first study was conducted to evaluate yield, fruit weight, fruit quality, and shelf life of ‘Geronimo’, ‘Quest’, and ‘Trust’ tomatoes planted in perlite and pruned to three or four fruit per cluster. The second study was conducted to determine the initial cost of perlite, pine bark, and rockwool growing media and their effect on yield of ‘Quest’ pruned to three or four fruit per cluster. ‘Geronimo’ produced the highest total marketable yield and ‘Trust’ produced the lowest. ‘Trust’ produced more cull yield and lower fruit weight than ‘Geronimo’ or ‘Quest’. Pruning clusters to three fruit increased total marketable yield and fruit weight, and reduced cull yield of all cultivars. Only ‘Geronimo’ produced higher early marketable yield at four fruit per cluster. All cultivars produced higher early marketable yield in 2007 than in 2006. Tested cultivars had similar fruit content of potassium and sodium and similar concentration of soluble solids. ‘Trust’ fruit had a higher pH than the other two cultivars. About 92% of ‘Quest’ tomatoes remained marketable after storage at 67 °F for 1 week. ‘Geronimo’ and ‘Trust’ had only 83% and 78% marketable fruit, respectively, under the same conditions. Initial costs to grow greenhouse tomatoes in perlite were higher than in rockwool, and were the lowest in pine bark. Plants grown in perlite produced higher total marketable yield than plants grown in either of the other media. They produced lower cull yield than plants grown in rockwool, but produced similar cull yield to plants grown in pine bark. Pruning clusters to three fruit increased total marketable yield and fruit weight in both studies. Pruning clusters to four fruit increased cull yield in both studies regardless of planting year.


2021 ◽  
pp. 104-109
Author(s):  
Chernysh O.O.

The urgency of the researched problem is connected with the growing role of mass media in modern conditions leads to change of values and transformation of identity of the person. The active growth of the role of the media, their influence on the formation and development of personality leads to the concept of “media socialization” and immutation in the media. The aim of the study is to outline the possibilities of the process of media socialization in the context of immutation in the media. The methods of our research are: analysis of pedagogical, psychological, literature, synthesis, comparison, generalization. The article analyzes the views of domestic and foreign scientists on the problem of immutation in the media and the transformation of the information space. In the context of the mass nature of the immutation of society, the concept of “media socialization” becomes relevant, which is the basis for reducing the negative impact of the media on the individual.The author identifies the lack of a thorough study of the concept of “media socialization” in modern scientific thought. Thus, media socialization is associated with the transformation of traditional means of socialization, and is to assimilate and reproduce the social experience of mankind with the help of new media.The article analyzes the essence of the concepts “media space”, “mass media” and “immutation”. The influence of mass media on the formation and development of the modern personality is described in detail.The study concluded that it is necessary to form a media culture of the individual, to establish safe and effective interaction of young people with the modern media system, the formation of media awareness, media literacy and media competence in accordance with age and individual characteristics for successful media socialization. The role of state bodies in solving the problem of media socialization of the individual was also determined. It is determined that the process of formation of media culture in youth should take place at the level of traditional institutions of socialization of the individual.The author sees the prospect of further research in a detailed analysis and study of the potential of educational institutions as an institution and a means of counteracting the mass nature of the immutation of society.Key words: immutation, media socialization, mass media, media space, information.


2021 ◽  
pp. 1-26
Author(s):  
Sigrid Denver ◽  
Tove Christensen ◽  
Jonas Nordström

Abstract Objective: The objective is to analyze Danish consumers’ attitudes to buying food with reduced salt content. Design: The study is based on a comprehensive store intervention that included 114 stores belonging to the same supermarket chain. Three different salt claims were tested for eight weeks on six test products within the categories bread, cornflakes and frozen pizzas. Scanner data were supplemented with 134 brief interviews with consumers in nine selected stores. Setting: Stores spread across Denmark. Participants: Consumers who buy food in the stores. Results: Statistical regression analyses of the scanner data indicated that none of the three claims significantly affected demand for any of the test products. The interviews confirmed that many consumers were more focused on other elements of the official dietary advice than reduced salt consumption, such as eating plenty of vegetables, choosing products with whole grains and reducing their intake of sugar and fat. Conclusions: Overall, both the scanner data and the interviews pointed in the same direction, toward the conclusion that salt content is often a secondary factor when Danish consumers make dietary choices.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Amandine Leroy ◽  
Xavier Falourd ◽  
Loïc Foucat ◽  
Valérie Méchin ◽  
Fabienne Guillon ◽  
...  

Abstract Background Biomass recalcitrance is governed by various molecular and structural factors but the interplay between these multiscale factors remains unclear. In this study, hot water pretreatment (HWP) was applied to maize stem internodes to highlight the impact of the ultrastructure of the polymers and their interactions on the accessibility and recalcitrance of the lignocellulosic biomass. The impact of HWP was analysed at different scales, from the polymer ultrastructure or water mobility to the cell wall organisation by combining complementary compositional, spectral and NMR analyses. Results HWP increased the kinetics and yield of saccharification. Chemical characterisation showed that HWP altered cell wall composition with a loss of hemicelluloses (up to 45% in the 40-min HWP) and of ferulic acid cross-linking associated with lignin enrichment. The lignin structure was also altered (up to 35% reduction in β–O–4 bonds), associated with slight depolymerisation/repolymerisation depending on the length of treatment. The increase in $${T}_{1\rho }^{H}$$ T 1 ρ H , $${T}_{HH}$$ T HH and specific surface area (SSA) showed that the cellulose environment was looser after pretreatment. These changes were linked to the increased accessibility of more constrained water to the cellulose in the 5–15 nm pore size range. Conclusion The loss of hemicelluloses and changes in polymer structural features caused by HWP led to reorganisation of the lignocellulose matrix. These modifications increased the SSA and redistributed the water thereby increasing the accessibility of cellulases and enhancing hydrolysis. Interestingly, lignin content did not have a negative impact on enzymatic hydrolysis but a higher lignin condensed state appeared to promote saccharification. The environment and organisation of lignin is thus more important than its concentration in explaining cellulose accessibility. Elucidating the interactions between polymers is the key to understanding LB recalcitrance and to identifying the best severity conditions to optimise HWP in sustainable biorefineries.


2021 ◽  
Vol 11 (4) ◽  
pp. 1423
Author(s):  
José Manuel Salmerón Lissen ◽  
Cristina Isabel Jareño Escudero ◽  
Francisco José Sánchez de la Flor ◽  
Miriam Navarro Escudero ◽  
Theoni Karlessi ◽  
...  

The 2030 climate and energy framework includes EU-wide targets and policy objectives for the period 2021–2030 of (1) at least 55% cuts in greenhouse gas emissions (from 1990 levels); (2) at least 32% share for renewable energy; and (3) at least 32.5% improvement in energy efficiency. In this context, the methodology of the cost-optimal level from the life-cycle cost approach has been applied to calculate the cost of renovating the existing building stock in Europe. The aim of this research is to analyze a pilot building using the cost-optimal methodology to determine the renovation measures that lead to the lowest life-cycle cost during the estimated economic life of the building. The case under study is an apartment building located in a mild Mediterranean climate (Castellon, SP). A package of 12 optimal solutions has been obtained to show the importance of the choice of the elements and systems for renovating building envelopes and how energy and economic aspects influence this choice. Simulations have shown that these packages of optimal solutions (different configurations for the building envelope, thermal bridges, airtightness and ventilation, and domestic hot water production systems) can provide savings in the primary energy consumption of up to 60%.


Author(s):  
David Philip Green ◽  
Mandy Rose ◽  
Chris Bevan ◽  
Harry Farmer ◽  
Kirsten Cater ◽  
...  

Consumer virtual reality (VR) headsets (e.g. Oculus Go) have brought VR non-fiction (VRNF) within reach of at-home audiences. However, despite increase in VR hardware sales and enthusiasm for the platform among niche audiences at festivals, mainstream audience interest in VRNF is not yet proven. This is despite a growing body of critically acclaimed VRNF, some of which is freely available. In seeking to understand a lack of engagement with VRNF by mainstream audiences, we need to be aware of challenges relating to the discovery of content and bear in mind the cost, inaccessibility and known limitations of consumer VR technology. However, we also need to set these issues within the context of the wider relationships between technology, society and the media, which have influenced the uptake of new media technologies in the past. To address this work, this article provides accounts by members of the public of their responses to VRNF as experienced within their households. We present an empirical study – one of the first of its kind – exploring these questions through qualitative research facilitating diverse households to experience VRNF at home, over several months. We find considerable enthusiasm for VR as a platform for non-fiction, but we also find this enthusiasm tempered by ethical concerns relating to both the platform and the content, and a pervasive tension between the platform and the home setting. Reflecting on our findings, we suggest that VRNF currently fails to meet any ‘supervening social necessity’ (Winston, 1996, Technologies of Seeing: Photography, Cinematography and Television. British: BFI.) that would pave the way for widespread domestic uptake, and we reflect on future directions for VR in the home.


2014 ◽  
Vol 652 (1) ◽  
pp. 206-221
Author(s):  
Anton Harber

Two decades of contestation over the nature and extent of transformation in the South African news media have left a sector different in substantive ways from the apartheid inheritance but still patchy in its capacity to fill the democratic ideal. Change came fast to a newly open broadcasting sector, but has faltered in recent years, particularly in a public broadcaster troubled by political interference and poor management. The potential of online media to provide much greater media access has been hindered by the cost of bandwidth. Community media has grown but struggled to survive financially. Print media has been aggressive in investigative exposé, but financial cutbacks have damaged routine daily coverage. In the face of this, the government has turned its attention to the print sector, demanding greater—but vaguely defined—transformation and threatened legislation. This has met strong resistance.


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