Kg Of Powder Research Articles

A MODEL OF ECOLOGICAL CHARCOAL PRODUCTION THROUGH HERBACEAOUS PLANTS IN THE URBAN COMMUNE OF NZEREKORE, REPUBLIC OF GUINEA

The world is confronted to various environmental problems caused by anthropogenic activities, mainly deforestation. This is why promoting the use of herbaceous plants in charcoal production will contribute to the fight against deforestation. In this paper we propose a simple model for producing ecological charcoal using herbaceous plants. The choice of the herbaceous species, the collection, weighing, drying, carbonization, crushing, sieving, kneading, compacting and drying of the briquettes are the different process which allowed us to produce this ecological charcoal based on herbaceous plants. 180kg of soaked weight of herbaceous gave us 90kg of dry weight, carbonized and crushed we obtained 8kg of powder and 1 kg of residue. These 8 kg of herbaceous powder allowed us to produce 156 briquettes of charcoal. A comparison of the physicochemical parameters of our ecological charcoal was made with the charcoal consumed in the urban commune of Nzerekore (wood charcoal). The Results showed that our produced charcoal model releases heat more slowly than wood charcoal, heats up more slowly than wood charcoal and its maximum temperature and heat quantity are higher than that of wood charcoal. The maximum temperature (98.9°C) is reached at 20 minutes for ecological charcoal (charcoal from herbaceous plants) and 97.9°C at 10 minutes for wood charcoal.

A metal hydride compressor for a small scale H2 refuelling station

The use of hydrogen as energy vector implies the development of the necessary infrastructures for hydrogen handling. A two-stage metal hydride compressor was developed and integrated in a small-scale hydrogen refuelling station at prototype level. In this work, the compression on site of green hydrogen using metal hydrides is exhaustively presented taking into account all the necessary aspects to bridge the gap between the laboratory and the real application. In particular, all aspects for the setting up of a metal hydride compressor, i.e. selection and characterization of selected metal hydrides, sizing of the plant components, design and the tests aimed to optimize the working performances are presented and deeply discussed, including energy consumption and efficiency necessary to build up a commercial system. The compressor employs two commercial alloys, i.e. a La0.9Ce0.1Ni5 from Labtech in the first stage and the Hydralloy-C5 from GfE in the second one. Working between room temperature for absorption and 150 °C for desorption, the hydrogen produced by the electrolyser at 28 bar is compressed up to 250 bar, resulting in a compression ratio of about 9. The metal hydride compressor has a final power consumption of 614 W, of which 85 W are linked to the hydrogen sorption reactions, while other contributions come from the pumps involved in the plant and the dissipations. The compressor presents an isentropic efficiency of about 11% for less than 1 kg of powder in each stage and an average H2 flowrate of 104 Nl/min is observed. The performances of the plant were optimized and maintained for a working time of about 245 h.

Design and Qualification of Pr–Fe–Cu–B Alloys for the Additive Manufacturing of Permanent Magnets

AbstractThe direct use of an advanced binder‐free additive manufacturing technique, namely laser powder bed fusion (L‐PBF), does not easily allow obtaining variously shaped, fully dense Nd–Fe–B magnets with high coercivity. The process inherently leads to the re‐melting of the powder and appearance/disappearance of undesired/desired microstructural features responsible for low and large coercivity. In this work, the development of a useful microstructure responsible for high coercivity in Pr21Fe73.5Cu2B3.5 and Nd21Fe73.5Cu2B3.5 alloys and a possible way to produce fully dense permanent magnets via additive manufacturing processes is demonstrated using: (i) suction casting technique, which provides a high cooling rate and thus similar microstructures as in L‐PBF but requires only very small amounts of powder; (ii) conventional L‐PBF processing using kg of powder, and (iii) a subsequent annealing treatment that is similar to a conventional sintering treatment. The subsequent heat treatment is necessary to develop high coercivity by forming a novel microstructure: hard magnetic (Nd,Pr)2Fe14B grains embedded in a matrix of intermetallic (Nd,Pr)6Fe13Cu phase. Furthermore, it is demonstrated that Pr21Fe73.5Cu2B3.5 exhibits a higher coercivity than Nd21Fe73.5Cu2B3.5 because of a finer and more homogeneous grain size distribution of the Pr2Fe14B phase. The final L‐PBF printed Pr21Fe73.5Cu2B3.5 samples provide a coercivity of 0.75 T.

Economic analysis and drying kinetics of a geothermal‐assisted solar dryer for tomato paste drying

The economic value of many fruit and vegetables is often linked to the ability to preserve such natural products. In the case of tomatoes, the manufacture of 1 kg of powder or concentrate requires the evaporation of about 16 kg water kg-1 dry matter. In the present work, the effectiveness and economic analysis of solar drying systems for drying of tomato paste with and without geothermal water heat exchanger (GWHE) were studied. The GWHE integration significantly increased the recorded drying temperature up to 53.41 °C, with an improvement of 11.5 °C compared to the conventional dryer. Moreover, the drying temperature inside the drying chamber exceeded ambient temperature after sunset and at night by 30.8°C. GWHE ensured a continuous drying process, while drying time was 22 consecutive hours, compared to the basic dryer with 18 h in 3 days. Effective moisture diffusivity was found to be 1.617 × 10-9 and 1.202 × 10-9 m2 s-1 for hybrid and basic drying systems, respectively, using the slope. Three methods were used to perform economic analysis. The cumulative present worth of savings, at 23 382.6 USD, is much higher than the capital cost of the hybrid dryer, at 467 USD. The payback period is quite acceptable, at 2.21 years as compared to dryer lifetime of 15 years. Therefore, the hybrid dryer will dry tomato paste without additional charges for 12.79 years and is recommended for a large-scale tomato paste dryer. The hybrid system with GWHE ensures a continuous drying process during night-time, in addition to reduced drying time. The economic study revealed a high feasibility for the hybrid dryer, with a short payback period. © 2021 Society of Chemical Industry.

Effects of spray-dried bovine plasma protein in milk replacers fed at a high plane of nutrition on performance, intestinal permeability, and morbidity of Holstein calves

Spray-dried plasma protein (SDP) has been shown to improve growth and intestinal function in young calves when included in milk replacers (MR) fed at conventional rates. Use of an SDP and wheat protein blend to replace a portion of whey protein has been shown to perform similarly to using an all-whey protein control MR. However, a trend in the dairy industry is to feed calves for greater rates of growth during the preweaning period. The purpose of this study was to determine the effects of increasing amounts of SDP inclusion in MR on growth and health of calves fed at a high plane of nutrition. Young (<7 d) Holstein calves were offered starter and assigned to 1 of 5 MR treatments: an all-milk protein (whey) control MR (0SDP, n = 26) or MR containing 5% SDP (5SDP, n = 20), 7.5% SDP (7.5SDP, n = 14), 10% SDP (10SDP, n = 20), or 12% of an approximate 1:1 SDP plus wheat protein blend (PW, n = 17). All MR were formulated to contain 26% CP and 16% fat and were fed at a maximum rate of 1 kg of powder (as fed) from d 8 to 36. Amounts of MR powder were decreased by 25%/wk from d 37 to weaning at d 57. Thereafter, calves were provided only starter feed until the end of the study at d 63. On d 4, 15, 36, and 57, intestinal permeability was assessed via oral administration of lactulose and d-mannitol followed by analysis of lactulose and mannitol in blood at 60 min after administration. Increasing SDP led to a small linear decrease in MR consumed. There was a tendency for a positive linear relationship between increasing SDP and average daily gain of body weight, and SDP had mixed effects on body frame variables. Increasing SDP tended to increase fecal scores and increased the amount of fluid therapy given. Diet had no effect on intestinal permeability. Increasing SDP led to an increase in serum total cholesterol and serum urea N and tended to have a quadratic effect on serum glucose concentration on d 36. Calves fed PW tended to have increased withers height, increased intestinal permeability on d 36, and an increased likelihood of being medicated for any reason or being medicated for respiratory illness, but growth and health were not different from the control diet otherwise. Feeding PW led to an increase in serum total cholesterol and tended to lead to increased serum glucose concentration on d 36. Results of this study indicate that SDP can be included at up to 10% as fed in the MR of calves fed at a high plane of nutrition (1 kg/d of MR powder, as fed) with improvements in average daily gain. Additionally, a 1:1 SDP plus wheat protein blend can be used at 12% inclusion with no difference in most health and growth parameters.

Investigation of suitable spray drying conditions for sugarcane juice powder production with an energy consumption study

Sugarcane juice was spray-dried under various conditions to determine the most suitable drying conditions for the manufacture of sugarcane juice powder. Initially, fresh, 30°Brix and 50°Brix sugarcane juice samples were dried in a laboratory-scale spray dryer at an air-drying temperature between 130 °C and 170 °C using maltodextrin, Arabic gum and dietary fiber as drying aids. It appeared that sugarcane juice should be concentrated under vacuum to 30°Brix and added with at least 15% maltodextrin before drying at 170 °C in order to obtain dried powder product with a low drying cost. After conducting the experiments in the laboratory, sugarcane juice powders were produced in a factory using an industrial-scale spray dryer under five drying conditions. It was found that the energy cost of industrial-scale production of sugarcane juice powder ranged between 0.77 USD and 2.06 USD per kg of powder. According to the results of the industrial-scale experiments, the sugarcane juice powder should be produced using vacuum evaporation of the sugarcane juice to 30°Brix prior to adding maltodextrin at 30% by weight and then spray drying at 190 °C.

Properties of Detonation Nanostructured Titanium-Based Coatings

Titanium-based coatings were deposited on aluminum samples using cumulative-detonation equipment. The gas mixture consumption (propane-oxygen-air) was up to 5 m3 per 1 kg of powder. The titanium-based coatings were examined by scanning electron microscopy (SEM), transmission electron microscopy (TEM) with diffraction, x-ray phase analysis, hardness measurements, and plasticity adhesion/cohesion resistance scratch tests. It was shown that the detonation titanium-based coatings are characterized by the presence of nanodispersed ceramic compounds and exhibit high values of plasticity, hardness, and adhesion strength. The titanium-based coatings had an amorphous structure, high hardness of up to 16 GPa, and a tensile bonding strength ranging from 52.5 to 53.0 MPa. A failure mode occurring in the tested samples was cohesive within the inter and intralamellar structure of coating.

Fluidization and coating of very dense powders by Fluidized Bed Chemical Vapour Deposition

The hydrodynamic behaviour of a very dense tungsten powder, 75μm in median diameter and 19,300kg/m3 in grain density, has been studied in a fluidized bed at room temperature using nitrogen and argon as carrier gas. Even if fluidization was achieved, the small bed expansion indicated that it was imperfect. Then, the fluidization was studied at 400°C in order to investigate the feasibility of coating this powder by Fluidized Bed Chemical Vapour Deposition (FBCVD). In particular, the influence of the H0/D ratio (initial fixed bed height to reactor diameter) on the bed thermal behaviour was analyzed. It appeared that at least 1.5kg of powder (corresponding to a H0/D ratio of 1.8) was necessary to obtain an isothermal bed at 400°C. Finally, first results about alumina coatings on the tungsten powder by FBCVD from aluminium acetylacetonate are detailed. They show that for the quite low temperatures tested, the coatings are uniform on all bed particles and are formed of amorphous carbon containing alumina. This study demonstrates the efficiency to combine fluidization (instead of spouted bed) and CVD to coat such very dense powders.

Design of a Mixed Ionic/Electronic Conducting Oxygen Transport Membrane Pilot Module

AbstractIn the last years, a lot of ceramic materials were developed that, at higher temperatures, have a high electrical conductivity and a high conductivity of oxygen ions. Such mixed ionic/electronic conductors can be used to produce high‐purity oxygen. This work focuses on the realization of a pilot membrane module, with BSCF (Ba0.5Sr0.5Co0.8Fe0.2O3‐δ) perovskite selected as the membrane material. An amount of 500 kg of powder was industrially fabricated, spray‐granulized and pressed into tubes. The best operation conditions concerning energy consumption were calculated, and a module reactor was designed operating at 850 °C, with an air pressure of 15–20 bar on the feed site and a low vacuum of about 0.8 bar on the permeate site. Special emphasis was placed on joining alternatives for ceramic tubes in metallic bottoms. A first laboratory module was tested with a membrane area of 1 m2 and then advanced to a pilot module with 570 tubes and a capability of more than 300 000 L of pure oxygen per day.

Application of lipase treatment on carotenoids extraction from Chili (Capsicum annuum L.)

Five strains of lipase-producing bacteria were selected and determined for enzyme activity. As well as, the potential of enzymatic extraction on carotenoids from dried chili was also investigated. Among five strains, Bacillus subtilis yielded the highest lipase activity (25.5±0.2 U/ml) within 60 days of cultivation followed by Candida tropicalis(19.1±0.3 U/ml), Candida albicans (10.6±0.2 U/ml), Bacillus stearothermophilis (14.1±0.0 U/ml) and Bacillus sphaericus (0.6±0.2 U/ml). Lipase from B. subtilis and C. tropicaliswere applied for carotenoids extraction from chili samples (Capsicum annuum L.). During the experiments, the chili was cut, dried with freeze dryer and characterized. The chili sample dried with freeze-drying method had a final moisture content and fat content at 4.05±0.19% and 6.62±0.11%, respectively. The chili powder was applied for pigment extraction using enzyme and solvent extraction. The highest carotenoids content (6.26 g of total carotenoids/ kg of powder) was obtained from dried chili extracted with lipase fromB. subtilis at lipase concentration of 25 U/ml. In particular, extraction with lipase from B.subtilis, yielded an increase of 1.56 folds for carotenoids content as compared to control. Key words: Bacillus subtilis, Candida tropicalis, Capsicum annuum, carotenoids,enzymatic extraction, lipase.

Polyneuritis due to alimentary poisoning with Davydov's drug

In recent years in the USSR, P. N. Davydov's preparation consisting of clay (90%) and talc (10%), carefully mixed and soaked with 30% arsenic acid sodium solution, has been used as a dry disinfectant. A 0.75 kg of powder is used to etch 1 m of seed. It is dressed no earlier than one month before sowing in special dressing machines.