Telah dilakukan penelitian untuk menentukan nilai koefisien dan efektivitas absorbsi bunyi dengan resonansi space dan sound level meter TS 1351. Material yang digunakan rockwool dengan variasi ...ketebalan 1 cm, 2 cm, 3 cm, 4 cm, 5 cm, 6 cm dan 7 cm. Pengukuran pada frekuensi sumber 2000 Hz, 3000 Hz, 4000 Hz, 5000 Hz, 6000 Hz dan 7000 Hz. Koefisien koefisien absorbsi rockwool (α) bernilai 0,04 – 0,08 dan terdapat perbedaan pada ketebalan 1 cm dan 2 cm disebabkan tingkat kerapatan rockwool yang berbeda. Efektivitas absorbsi terhadap kemampuan menyerap bunyi paling baik dimiliki oleh ketebalan 7 cm. Pada ketebalan 7 cm memiliki efektivitas absorbsi pada range frekuensi yang tinggi antara frekuensi 4000 Hz, 5000 Hz, 6000 Hz dan 7000 Hz dengan nilai efektivitas 27,86%, 30,84%, 31,24% dan 29,95%. Sedangkan frekuensi 2000 Hz dan 3000 Hz nilai efektivitas absorbsi pada ketebalan rockwool 6 cm dengan nilai 31,78% dan 27,27%. Sehingga rockwool dapat digunakan sebagai media/bahan absorbsi gelombang bunyi pada range frekuensi tertentu.
In this digital world, all the developing countries' growth has improved drastically with farmers' influence and innovative farming processes. Generally, the farming process includes ancient ...traditional methodologies for maintaining the crops' quality and yields. Their farming was developed and has given more profit only with the quality of the soil and the nutrition used on land. But the drawback is they were spending much time to get their yields from their land, and the nutrition level was not maintained at all times. Moreover, more space was used for farming, with huge manpower required to maintain the entire land. Most countries are moved to smart farming concepts with IoT platforms to optimize the time and techniques. In that hydroponic, the best innovative idea to produce more crops, vegetables, and fruits without soil. Rockwool is used for farming processes with water contaminants at regular intervals will provide huge productions as well as no need to wait for a long time for cultivation. This method was implemented in most of the countries that were doing smart farming with less manpower and low cost. The hydroponic farming methodology is implemented with IoT sensors for monitoring crop's status and health continuously. Once their nutrition level or water level has decreased, it will provide all at constant time intervals to the entire system effectively. A few years ago, hydroponic farming was horizontally implemented on smaller spaces for the regular water flow. But now a day it is implemented on a vertical surface to reduce the space, and water flow is only at the time of need. This technology is used to increase the productivity of the crops with a small space of land and less manpower. Perhaps the cost of the entire system has been taken into consideration by small-scale unit farmers; vertical hydro farming provides better results when compared with previous classical methods. This research paper has given the design and implementation of automated vertical hydro farming techniques with IoT platforms, and their analytics will be done using big data analytics.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ
•Granulated slag, rockwool, and silica fume wastes are remanufactured to get a synthetic geopolymer.•The physical and mechanical properties of the obtained geopolymer are adequate for industrial ...applications.•Curing time is critical in getting the best properties for the synthetic geopolymer; 28 days is chosen as the most effective time.
The substantial target of this work is to manufacture sustainable geopolymers by recycling low cost industrial wastes (granulated slag, GS; rockwool, RW; and silica fume, SF). To reveal the mineral and chemical compositions of these industrial solid wastes, they were investigated using X-ray diffraction (XRD), Fourier transform Infrared spectroscopy (FTIR), and X-ray fluorescence (XRF). The granulated slag, rockwool and silica fume were blended with the convenient quantity of alkaline reactor to formulate a hydrated pattern of geopolymers. The phase configuration, physico-mechanical effects compressive strength (CS), porosity and bulk density and the microstructural form of the geopolymers were studied via the X-ray diffraction, hydraulic mechanical testing device, helium pycnometer, and Field emission Scanning electron microscope (FE-SEM), respectively. The results declared that the partial substitution of RW by various ratios of SF in presence of GS affect successfully on the physico-mechanical properties of hardened geopolymers. Implication of 2 % SF boosts the physico-mechanical features of the 50GS-48RW hardened geopolymers at all curing ages especially at the age of 28 days. Therefore, the geopolymer 50GS-48RW-2SF displayed the best physico-mechanical characteristics especially the CS at 28-days (39.12 MPa) owing to the formation of diverse hydration products like CSHS, CAHS and NASHs. These results were confirmed via FE-SEM/EDX images that exhibited compact and dense microstructure rod-like crystals of CSHs and three dimensional framework structures of NASHs.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Vapor pressure deficit (VPD) is considered to be one of the major environmental factors influencing stomatal functions and photosynthesis, as well as plant growth in crop and horticultural plants. In ...the greenhouse cultivation, air temperature and relative air humidity are regulated by switching on/off the evaporative systems and opening/closing the roof windows, which causes VPD fluctuation. However, it remains unclear how VPD fluctuation affects photosynthetic and growth performance in plants. Here, we examined the effects of the VPD fluctuation on the photosynthetic and growth characteristics in lettuce (
L.). The parameters for gas exchange and chlorophyll fluorescence and biomass production were evaluated under the conditions of drastic (1.63 kPa for 6 min and 0.63 for 3 min) or moderate (1.32 kPa for 7 min and 0.86 kPa for 3 min) VPD fluctuation. The drastic VPD fluctuation induced gradual decrease in stomatal conductance and thus CO
assimilation rate during the measurements, while moderate VPD fluctuation caused no reduction of these parameters. Furthermore, data showed moderate VPD fluctuation maintained leaf expansion and the efficiency of CO
diffusion across leaf surface, resulting in enhanced plant growth compared with drastic VPD fluctuation. Taken together, fine regulation of VPD can be crucial for better plant growth by maintaining the photosynthetic performance in lettuce. The present work demonstrates the importance of VPD control during plant cultivation in plant factories and greenhouses.
Rockwool (RC) and peat are two common substrates used worldwide in horticultural crop production. In recent years environmental and ecological concerns raised the demand for reducing the use of RC ...and peat. Although coconut coir (CC) has been increasingly used as an alternative to RC and peat, it is still needed to comprehensively evaluate the feasibility of CC before widely used. To meet this need, CC, RC, and peat-vermiculite (PVC) cultivations were used as tomato cultivation substrates to evaluate their effects on EC, pH and mineral ions in root-zone solution and drainage, nutrient uptake by crops, nutrient balance of cultivation system, plant growth and fruit quality. In general, CC significantly increased K and S uptake by crops, photosynthesis, individual fruit weight and total fruit yield compared to RC, and increased P and K uptake by crops and total fruit yield compared to PVC. Moreover, CC significantly increased organic acid of fruit in first truss compared to both RC and PVC. The uncredited nutrient was overally lower under CC than under RC and PVC (the lower, the better). For all substrates, the blossom-end rot (BER) of fruit increased gradually from 3rd to 13th trusses. The BER of fruit was not significantly influenced by CC compared to RC or PVC, but was sginificantly decreased by PVC compared to RC. Our results infer that CC was a potential substrate that could be widely used in tomato production. However, the inhibition of BER was still a challenge when CC was used as cultivation substrate for tomato.
Decreasing arable land, rising urbanization, water scarcity, and climate change exert pressure on agricultural producers. Moving from soil to soilless culture systems can improve water use ...efficiency, especially in closed-loop systems with a recirculating water/nutrient solution that recaptures the drain water for reuse. However, the question of alternative materials to peat and rockwool, as horticultural substrates, has become increasingly important, due to the despoiling of ecologically important peat bog areas and a pervasive waste problem. In this paper, we provide a comprehensive critical review of current developments in soilless culture, growing media, and future options of using different materials other than peat and rockwool. Apart from growing media properties and their performance from the point of view of plant production, economic and environmental factors are also important. Climate change, CO2 emissions, and other ecological issues will determine and drive the development of soilless culture systems and the choice of growing media in the near future. Bioresources, e.g., treated and untreated waste, as well as renewable raw materials, have great potential to be used as growing media constituents and stand-alone substrates. A waste management strategy aimed at reducing, reusing, and recycling should be further and stronger applied in soilless culture systems. We concluded that the growing media of the future must be available, affordable, and sustainable and meet both quality and environmental requirements from growers and society, respectively.
In agriculture, the increasing scarcity of arable land and the increase in extreme weather conditions has led to a large proportion of crops, especially vegetables, being cultivated in protected ...soilless cultivation methods to provide people with sufficient and high-quality food. Rockwool has been used for decades as a soil substitute in soilless cultivation. Since rockwool is not biodegradable, it is disposed in landfills after its use, which nowadays leads to ecological concerns and drives the search for alternative substrates, especially organic materials. The objectives of this study were to investigate the effects of organic materials (wood chips, sphagnum moss, and hemp fibers) in relation to rockwool substrate on plant growth and quality of lettuce as a result of physical and chemical properties of the mentioned substrates. We were able to show that sphagnum moss is a suitable substitute substrate for lettuce cultivation, contrary to hemp. All investigated substrates presented good physical properties, but differed in their decomposition stability. Within 8 weeks, 30% of the hemp and about 10% of both sphagnum and wood materials were degraded. It was concluded that the increased microbiological activity immobilized nitrogen and led to oxygen deficiency in the rhizosphere and resulted in increased phenolic acid contents in lettuce but poor yield on hemp. Sphagnum caused a pH decrease and accumulation of ammonium in the nutrient solution and allowed the highest yield for lettuce at moderate phenolic acid contents. Low yields were obtained on wood, which could possibly be increased by optimized nutrient solution, so that wood as an alternative to rockwool was not excluded. By applying used organic substrates as soil additives on arable land, the nutrients accumulated in it might fertilize the open field crops, thus saving mineral fertilizers. This, together with the avoidance of waste, would contribute to a greater sustainability.
This study investigates the biofortification of tomato and lettuce plants with strontium (Sr). The Sr was applied at 0, 25, and 50 mg kg
−1
in the soil experiment and 0, 2.5, and 5.0 mg L
−1
in the ...rockwool experiment. The Sr application increased growth of plants. The Sr concentration in soil-grown tomato increased from 137 to 384 and 665 mg kg
−1
with Sr treatments, respectively. Similarly, Sr concentration in tomato fruits rose from 4.53 to 10.7 and 17.5 mg kg
−1
. Lettuce Sr concentration increased from 64.9 to 119 and 168 mg kg
−1
with Sr treatments. The Sr concentration in the vegetative parts of tomatoes grown in rockwool increased from 23 to 600 mg kg
−1
with low-Sr and to 604 mg kg
−1
with high-Sr application. Similarly, the Sr concentration in tomato fruits increased from 1.13 to 25.7 and 19.0 mg kg
−1
with Sr treatments. The Sr concentration in lettuce grown in rockwool increased from 26.2 to 285 and 356 mg kg
−1
with Sr, respectively. The fruit Ca concentrations significantly increased in response to the applied high-Sr in soil-grown tomato plants. In rockwool-grown tomato, the Ca concentrations in the vegetative parts increased from 19.3 to 27.8 g kg
−1
, and in the fruits, it increased from 0.66 to 1.00 g kg
−1
under the low-Sr treatment compared to the control. In rockwool-grown lettuce, the Ca concentration increased with the low-Sr. In conclusion, the present research establishes that the biofortification of Sr in the edible parts of tomato and lettuce plants can be achieved successfully.
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BFBNIB, GIS, IJS, KISLJ, NUK, PNG, UL, UM, UPUK
Rockwool is an inorganic fiber with interesting properties obtained from basaltic rocks. It can possibly be used in rubber technical products which work under critical conditions in several ...industries. This study aims to investigate properties of three short rockwool fibers/nitrile rubber composites. Ten formulations were prepared with 10, 25 and 40 phr of rockwool fibers with different length and modification. The composites were assessed on its morphological aspects, thermal, rheological, and mechanical behaviors. The results remarked that the rockwool fiber with chemical modification had better interfacial interaction with the polymer enhancing modulus at 100% of deformation, Shore A hardness, tear strength, Payne effect and stress relaxation under a compressive regime. An outstanding result was observed for the composite with 10 phr of fiber with chemical modification that had less stress relaxation when compared with the unfilled NBR indicating an excellent possibility of use of this fiber in materials that work under compressive forces. The difference in length of the rockwool fibers (125 μm–300 μm) did not interfere significantly on most of the results.
•All fibers studied did not interfere on vulcanization times of NBR.•Payne effect reduced considerably on composites with modified fiber.•SEM micrographs showed the stronger rubber/fiber adhesion in composites with modified fiber.•Composite R2-10 had lower stress relaxation under a compressive regime when compared to the NBR.•Tensile strength results and SEM micrographs suggested that the fibers did not assume a preferential orientation on the polymeric matrixes.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ
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