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1

Ocena efektywności tłoczenia i jakości oleju uzyskanego z nasion lnu i konopi poddanych obróbce mikrofalowej

Krajewska Marta, Starek-Wójcicka Agnieszka, Soja Jakub

Przemysł Chemiczny

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2023

|

T. 102, nr 10

1029--1035

PL

Przeprowadzono badania nad możliwością poprawy efektywności tłoczenia oleju poprzez zastosowanie obróbki mikrofalowej nasion lnu zwyczajnego (Linum usitatissimum L.) odmiany Luna oraz konopi siewnych (Cannabis sativa L.) odmiany Beniko. Badane nasiona nawilżano do wilgotności 6,5 i 8,5%, następnie ogrzewano mikrofalowo przez 3 i 7 min, po czym tłoczono z nich olej w prasie Sana marki Omega. Otrzymany olej oceniano pod względem zaawansowania zmian hydrolitycznych (LK, liczba kwasowa), zawartości pierwotnych produktów utlenienia (LN, liczba nadtlenkowa), stabilności oksydacyjnej w teście Rancimat oraz barwy. Wykazano, że 3-minutowe ogrzewanie mikrofalowe nasion lnu i konopi o wilgotności 8,5% wpłynęło na zwiększenie wydajności tłoczenia oleju w stosunku do próby kontrolnej odpowiednio o ok. 10,52 i 11,36%. Stwierdzono zwiększenie stabilności oksydacyjnej olejów z nasion poddanych obróbce mikrofalowej. Czas indukcji wzrastał stopniowo wraz z wydłużaniem czasu ogrzewania. Najlepszą stabilnością oksydacyjną (olej konopny 5,64 h, olej lniany 6,46 h) charakteryzował się olej otrzymany z nasion nawilżonych do 6,5% i ogrzewanych przez 7 min.

EN

Flax seeds (Linum usitatissimum L.) of the Luna variety and hemp seeds (Cannabis sativa L.) of the Beniko variety were moisturized to a moisture content of 6.5% and 8.5%, then heated in a microwave oven for 3 and 7 min. The pressed oil was evaluated for the progression of hydrolytic changes (acid number), the content of primary oxidn. products (peroxide number), oxidative stability in the Rancimat test and color. Microwave heating of flax and hemp seeds with a moisture of 8.5% for 3 min increased the oil pressing efficiency by 10.52% and 11.36%, resp., compared to the control sample (without heating). The induction time gradually increased with longer heating time and the best results amounted to 5.64 h and 6.46 h for hemp and linseed oil, resp., obtained from seeds with a moisture of 6.5% and heated for 7 min.

2

Microwave heating process – characteristics, benefits, hazards and use in food industry and households – a review ®

Pielak Marlena, Czarniecka-Skubina Ewa, Kraujutienė Ingrida

Postępy Techniki Przetwórstwa Spożywczego

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2022

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nr 1

152--167

EN

The article presents the advantages and disadvantages of using microwave heating in the food industry and in households. A review of the literature in this field revealed many positive aspects of microwave heating. The microwave oven enables fast heat transfer, which translates into a short heating time and high energy efficiency compared to a conventional heating process. The efficiency of the process depends on many factors, including the shape and size of the product, the properties and position of the food during heating, and the process parameters used. However, the challenge for producers is still uneven temperature distribution, and hence uneven heating of the product. In summary, the quality of food prepared in a microwave oven differs from that of food prepared with conventional heating. The authors report both the highest and average sensory quality of vegetables prepared in a microwave oven and good nutrients retention. However, microwave heating also raises concerns among consumers due to the penetration of waves into the product and among other the possibility of acrylamide formation, as well as the safety of people operating the devices. Based on the research, it is known that the combination of microwave heating and conventional methods significantly improves the efficiency of the process, affecting the higher product quality, including the microbiological quality of the products obtained in this way.

PL

W artykule przedstawiono zalety i wady stosowania ogrzewania mikrofalowego w przemyśle spożywczym oraz w gospodarstwach domowych. Przegląd literatury z tego zakresu wykazał wiele pozytywnych aspektów ogrzewania mikrofalowego. Kuchnia mikrofalowa umożliwia szybki transfer ciepła, co przekłada się na krótki czas nagrzewania, wysoką efektywność energetyczną w porównaniu z konwencjonalnym procesem ogrzewania. Wydajność procesu zależy od wiele czynników, m.in. kształtu i wielkości produktu, właściwości i położenia żywności podczas ogrzewania a także zastosowanych parametrów procesu. Wyzwanie dla producentów wciąż jednak stanowi nierównomierny rozkład temperatury, a co za tym idzie nierównomierne nagrzewanie się produktu. Podsumowując, jakość żywności przygotowanej w kuchence mikrofalowej różni się w porównaniu z żywnością przygotowywaną za pomocą ogrzewania konwencjonalnego. Autorzy donoszą zarówno o najwyższej, jak i przeciętnej jakości sensorycznej warzyw przygotowanych w kuchni mikrofalowej oraz o dobrym zachowaniu składników odżywczych. Jednakże ogrzewanie mikrofalowe budzi też obawy wśród konsumentów ze względu na wnikanie fal w głąb produktu i m.in. możliwość tworzenia się akryloamidu, a także bezpieczeństwo osób obsługujących urządzenia. Na podstawie badań wiadomo, że połączenie ogrzewania mikrofalowego i metod konwencjonalnych znacznie poprawia wydajność procesu, wpływając na wyższą jakość produktu, w tym jakość mikrobiologiczną tak uzyskanych produktów.

3

Modeling and Box-Behnken design optimization of microwave treatment of sulphidic gold flotation tailing

Benli Birgül, Baştürkçü Hüseyin

Physicochemical Problems of Mineral Processing

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2022

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Vol. 58, iss. 5

art. no. 149929

EN

As raw minerals become scarcer every passing day, the need for the recovery of mine tailings becomes essential. This research highlights the use of microwave energy as a green alternative to otherwise environmentally harmful methods of ore tailing recovery. The obtained results indicate that a 1.4 ppm Au and 3.5 % S sample floated with Aeroflot 208 and Aerophine 3418A increased the concentration of tailings over 18 % S and 4 ppm, Au, for recovery yield, resulting in 84 % and 80 % recovery, respectively. After microwave irradiation, 90 % of sulphur removal was reached under the optimum conditions of 50 minutes of irradiation using 1000 W for 4 g of the sample. Overall with 96. 74 % correlation of the quadratic model using the Box-Behnken design and expressed coefficient R2 regression the model was proven to be suitable for heating and roasting processes of gold-bearing tailings.

4

The impact of microwave treatment on the chemical properties of sewerage sludge

Ing Doh Shu, Jaya Ramadhansyah Putra, Ho Chia Min, Chin Siew Choo, Nabiałek Marcin, Abdullah Mohd Mustafa Al Bakri, Garus Sebastian, Śliwa Agata

Archives of Civil Engineering

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2022

|

Vol. 68, nr 1

365--377

EN

Due to urbanization, the population in the major cities in Malaysia is approximately 72.8% of its total population. The increase of population density has directly increased the amount of sewerage sludge waste that poses threat to the environment. In line with the green initiatives, alternative method to develop good quality concrete material from sewerage sludge waste can be further explored. Traditionally, sewerage sludge waste is processed using incinerator that require high energy and it is time consuming. In this study, microwave heating which require less energy consumption and less time consuming is used for sewerage sludge preparation. Prior to heating process, sewerage sludge waste is over dried at 105°C for 24 hours. Three types of microwave heating namely medium heating, medium high heating and high heating has been used. The chemical and physical properties microwaved sewerage sludge ash (MSSA) was tested using X-Ray Fluorescence (XRF), X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). Based on the result, the recommended temperature for the MSSA production for the concrete is High Mode Temperature. This is due to the result of MSSA for X-Ray Fluorescent test as its shows the highest in the content for pozzolanic element which are SiO2 and Fe2O3 that produce after the microwave burning process. The mineralogical composition and the crystalline phase of the High temperature MSSA due to X-Ray Diffraction test also shows high content of SiO2 as the major component as it is good for pozzolanic reaction in concrete. From the Scanning Electron Microscope test, it is observed that particle of High heated MSSA are slightly smaller than other temperature. Also, the densification occurs at High temperature MSSA. Hence, the optimal burning temperature mode for MSSA is High Mode temperature.

5

Crack damage evolution in concrete coarse aggregates under microwave‑induced thermal stress

Yuan Yuan, Shao Zhushan, Qiao Rujia, Guo Xuan, Wang Weitao

Archives of Civil and Mechanical Engineering

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2022

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Vol. 22, no. 3

art. no. e108

EN

Coarse aggregates of waste concrete can be efficiently separated from mortar under microwave irradiation. However, the microwave-induced damage in aggregates are restricting mechanical properties of the aggregates for replacing natural aggregates. Since damage evolution in rocks treated by microwave are influenced by mineralogy and microwave operating parameters, such as power and irradiation time, understanding the microwave weakening mechanism of rocks is necessary to assess and control the damage of aggregates for recovery of high-quality concrete coarse aggregates. This article develops an approach for evaluating crack damage evolution in aggregates exposed to microwave by combining theoretical analysis with experimental investigation. A theoretical heat source-matrix model based on electromagnetic and thermal properties of mineral components is established for microwave heated aggregates. Substituting microwave irradiating parameters and mineralogy of the aggregates into the model, corresponding temperature fields and thermal stress fields are solved. Cracks in aggregates after microwave exposure are observed using scanning electron microscopy (SEM) and quantified in terms of crack length, density and intensity. Crack damage varied with microwave energy is assessed by crack length and density. Crack propagation is further discussed by contrast of stress intensity factor (SIF) at the crack tip and fracture toughness of the aggregate. Cracking behavior analyzed by SIF of cracks is consistent with that obtained from quantitative analysis on SEM images. The results suggest that granite shows a stronger resistance to thermal stress damage compared with basalt under microwave exposure, and a multistage microwave treatment should be adopted for recovery of various aggregates.

6

Wpływ sposobu nagrzewania i grubości rdzeni pomiarowych wykonanych z oliwinowych mas formierskich z krzemianem sodu na odkształcalność badaną na urządzeniu DMA Hot-Distortion

Stachowicz M., Paduchowicz P.

Prace Instytutu Odlewnictwa

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2018

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Vol. 58, no. 4

277--293

PL

W artykule podjęto tematykę wpływu podwyższonej temperatury na oliwinowe masy formierskie i rdzeniowe ze spoiwem nieorganicznym z grupy niemodyfikowanych gatunków uwodnionego krzemianu sodu. Sporządzone w warunkach laboratoryjnych masy na osnowie piasku oliwinowego formowano w kształtki prostopadłościenne do badania przemieszczenia wolnego końca rdzenia pomiarowego w warunkach otoczenia o podwyższonej temperaturze. W celu utwardzenia, wykonane z mas oliwinowych, kształtki poddawano szybkiemu nagrzewaniu mikrofalowemu w piecu z generatorem częstotliwości fali elektromagnetycznej f = 2,45 GHz i mocy wyjściowej 1000 W, w czasie 180 s. Badania przeprowadzono na kształtkach prostopadłościennych formowanych we wnęce o wymiarach: 25,9 × G × 120,4 mm, gdzie G = 6 lub 8, lub 10 mm. Pomiary przemieszczeń wolnego końca kształtek rdzeni pomiarowych przeprowadzono na zautomatyzowanym urządzeniu laboratoryjnym DMA Hot- Distortion. W trakcie pomiarów zastosowano trzy sposoby ogrzewania powierzchni prostopadłościennych kształtek spotykanych w technice pomiarowej odkształceń H-D (Hot Distortion Test): grzanie od dołu, grzanie od dołu i od góry (Modified Hot Distortion Test) oraz ogrzewanie tylko od góry. Przemieszczenie wolnego końca kształtek prostopadłościennych, w zależności od grubości oraz sposobów ogrzewania ich powierzchni, posłużyło do wstępnej oceny zachowania utwardzonych mikrofalowo mas oliwinowych z krzemianem sodu w warunkach otoczenia o podwyższonej temperaturze.

EN

The article raises the issue of the influence of increased temperature on olivine moulding and core sands with an inorganic binder from the group of unmodified kinds of hydrated sodium silicates. Produced at laboratory conditions, moulding sands with an olivine sand matrix were formed into cuboidal specimens to test the deformation of the free measuring core end at conditions of increased temperature. In order to harden, the measuring cores made of olivine moulding sands fast microwave heating was applied to which used was a furnace with an electromagnetic wave frequency generator f = 2.45 GHz and output power of 1000 W, in the time period of 180 s. Tests were carried out on cuboidal specimens moulded in a cavity with the dimensions 25.9 × G × 120.4 mm, where G = 6 or 8 , or 10 mm. Measurements of deformation of the free specimen end of the measuring cores were conducted on an automated laboratory DMA Hot-Distortion apparatus. During the measurements three techniques were used to heat the surfaces of cuboidal specimens which are applied in the Hot Distortion Test: heating from the bottom, heating from the bottom and the top (Modified Hot Distortion Test), and heating only from the top. The deformation of the free end of cuboidal specimens, depending on the thickness and heating techniques of their surfaces, served for the initial assessment of the behaviour of microwave hardened olivine moulding sands with sodium silicate at conditions of increased temperature.

7

Modified Hot Distortion Test to Investigate the Effect of the Inorganic Binder on the High-Temperature Behaviour of Physically Hardened Moulding Sands

Stachowicz M.

Archives of Foundry Engineering

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2018

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Vol. 18, iss. 2

45--50

EN

This study is an attempt to determine by Hot Distortion Test (HDT) the impact of physical methods of hardening inorganic binders in the moulding sands on phenomena caused by influence of thermal energy from heating elements with a temperature of 900°C +/- 10°C. Medium silica sand-based moulding mixtures were densified and then hardened using two physical methods: microwave heating at a frequency of 2.45 GHz or classical drying at a temperature of 110°C. Sodium silicate bonded sand (SSBS) with five unmodified kinds of hydrated sodium silicates subjected to two different types of hardening method were assessed in terms of their behaviour in high temperature. Thermal behaviour by means of deformation measurement was carried out with a modified Hot Distortion Test (mHDT). Due to this advanced, but unstable by appropriate standards Hot Distortion Test gives an opportunity to measure thermoplastic deformations (L) in moulding sands in many aspects, such as time of annealing. Research carried out in this way exposed differences between inorganic binders with molar module ranging from 3.4 to 2.0. It was established that deformations under the influence of high temperature last the longest in SSBS containing binders with molar module ranging from 3.4 to 2.9. Similarly, for these types of moulding sands the method of hardening the binder is found to be essential for increasing/decreasing the rate of thermoplastic deformations during the annealing of samples. The samples of SSBS made with binders with molar module from 2.5 to 2.0 are found to be excessively susceptible to thermoplastic deformation as a result of heating them in high environmental temperature presence.

8

Preparation of activated bentonite and its adsorption behavior on oil-soluble green pigment

Zheng R., Gao H., Ren Z., Cen D., Chen Z.

Physicochemical Problems of Mineral Processing

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2017

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Vol. 53, iss. 2

829--845

EN

The present research work focuses on effective preparation of activated bentonite (AB) and its application in removal of oil-soluble green pigment (OSGP) from either vegetable oils or food-processing wastewater. Mono-factor experiments were carried out to explore the effects of operation factors in preparation of AB. The parameters investigated were the effect of contact time, adsorbent dosage, initial OSGP concentration and temperature. The chemical composition, crystalline phases, microstructure and functional groups of prepared AB were characterized and evaluated by X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR), respectively. The adsorption kinetics and equilibrium isotherms were studied, finding that the adsorption process fitted better with the pseudo-second-order model and the Freundlich isotherm equation. In addition, thermodynamic parameters, such as standard the Gibbs free energy (ΔG°), standard enthalpy (ΔH°) and standard entropy (ΔS°) were also calculated, indicating that adsorption was spontaneous and endothermic. The findings of this investigation suggest that AB prepared through microwave activation as a cheap adsorbent holds great potential to remove oil-soluble green pigment in the wastewater treatment process.

9

Effect of Microwave Heating on Moulding Sand Properties with Gypsum Binder

Paduchowicz P., Stachowicz M., Granat K.

Archives of Foundry Engineering

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2017

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Vol. 17, iss. 3

97--102

EN

The paper presents results of initial research on the possibility of applying microwave radiation in an innovative process of making casting moulds from silica sand, where gypsum CaSO4∙2H2O was acting as a binding material. In the research were compared strengths and technological properties of moulding mixture subjected to: natural bonding process at ambient temperature or natural curing with additional microwave drying or heating with the use of microwaves immediately after samples were formed. Used in the research moulding sands, in which dry constituents i.e. sand matrix and gypsum were mixed in the ratio: 89/11. On the basis of the results of strength tests which were obtained by various curing methods, beneficial effect of using microwaves at 2.45 GHz for drying up was observed after 1, 2 and 5 hours since moisture sandmix was formed. Applying the microwaves for hardening just after forming the samples guarantees satisfactory results in the obtained mechanical parameters. In addition, it has been noted that, from a technological and economic point of view, drying the silica sand with gypsum binder in microwave field can be an alternative to traditional molding sand technologies.

10

Otrzymywanie polietylenu spienionego w warunkach ogrzewania mikrofalowego : badania rozpoznawcze

Brzozowska T., Makomaski G.

Przemysł Chemiczny

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2016

|

T. 95, nr 1

52--53

PL

Przedstawiono sposób otrzymywania polietylenu o strukturze porowatej w warunkach mikrofalowych pod wpływem chemicznych czynników spieniających. Zastosowano w tym celu dodatki wybranych poroforów oraz napełniacz zwiększający powinowactwo polimeru do pochłaniania promieniowania mikrofalowego. Stwierdzono, że rodzaj środka spieniającego w obecności napełniacza odgrywa istotną rolę w procesie spieniania w obecności mikrofal.

EN

Low-d. polyethylene was foamed in a microwave reactor by using chem. agents. The addn. of blowing agents and the filler resulted in an increase in the affinity of polymeric material to absorb the microwave radiation.

11

Experimental study on triboelectrostatic beneficiation of wet fly ash using Microwave Heating

Li H., Chen Y., Zhang X., Zhao Y., Tao Y., Li C., He X.

Physicochemical Problems of Mineral Processing

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2016

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Vol. 52, iss. 1

328--341

EN

Triboelectrostatic beneficiation, as a physical method, of fly ash cannot only meet the technical requirements of fly ash application but also recycle of an unburned carbon as a useful energy source. The aim of this study was to investigate the feasibility of improving efficiency of triboelectrostatic beneficiation of wet fly ash using microwave heating. The wet fly ash with different moisture contents had an average loss-on-ignition of 12.56%. The fly ash samples were heated in a microwave oven before the experiments. The experimental conditions were electric field voltage of 40 kV and air flux ranging from 12 to 30 m3/h. The influence of the microwave heating on the wet fly ash triboelectrostatic beneficiation was discussed under the conditions of different microwave intensity and irradiation time. The results indicated that the removal rate and recycle rate of the unburned carbon showed a significant increase performance as the wet fly ash was processed by the microwave heating which was attributed to changes of moisture contents and dielectric constants caused by the microwave heating. The feasibility had been verified according to the experimental study on fly ash with different moisture contents. It can be concluded that the microwave heating process was efficiently applied for the wet fly ash triboelectrostatic beneficiation.

12

Synthesis of SiC nanowhiskers from graphite and silica by microwave heating

Kahar S. M., Voon C. H., Lee C. C., Hashim U., Md Arshad M. K., Lim B. Y., Gopinath S. C. B., Rahman W.

Materials Science Poland

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2016

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Vol. 34, No. 4

770--779

EN

Silicon carbide (SiC) is an important ceramics for engineering and industrial applications due to its advantage to withstand in high temperatures. In this article, a demonstration of SiC nanowhiskers synthesis by using microwave heating has been shown. The mixtures of raw materials in the form of pellets were heated, using a laboratory microwave furnace, to 1400 °C for 40 minutes at a heating rate of 20 °C/min. The characterization process proved that the mixture of graphite and silica in the ratio of 1:3 is an ideal composition for synthesizing single phase β-SiC nanowhiskers. Vapor-solid mechanism was suggested to explain the formation of SiC nanowhiskers by the proposed microwave heating.

13

Projekt aplikatora do mikrofalowego spajania nawierzchni bitumicznych

Salski B., Olszewska-Placha M., Rudnicki J., Gwarek W., Karpisz T., Reszewicz S.

Elektronika : konstrukcje, technologie, zastosowania

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2015

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Vol. 56, nr 7

35-36

PL

W artykule opisano proces projektowania aplikatora do termicznego spajania nawierzchni bitumicznych przy pomocy mikrofal. Aplikator wyposażono w rożek falowodowy otoczony dławikiem w postaci regularnie ułożonych kołków cylindrycznych zapobiegających wyciekowi promieniowania elektromagnetycznego. Projekt wykonano przy pomocy symulatora elektromagnetycznego opartego na metodzie różnic skończonych w dziedzinie czasu. Rezultaty symulacji zostały wstępnie potwierdzone za pomocą przeprowadzonych eksperymentów. Uzyskano dużą zgodność symulacji z rzeczywistym zachowaniem aplikatora.

EN

In this paper a design cycle of a microwave applicator for thermal bonding of bituminous surfaces is discussed. The applicator is equipped with a dedicated waveguide horn surrounded with a choke composed of regularly distributed cylinders preventing unwanted electromagnetic radiation. The design has been made with the aid of an electromagnetic simulator based on a finite-difference time-domain method. Simulation results have been confirmed with experiments undertaken on a prototype of the applicator.

14

Influence of melt temperature on strength parameters of cyclically activated used-up sandmixes containing water-glass, hardened with microwaves

Stachowicz M., Granat K.

Archives of Civil and Mechanical Engineering

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2015

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Vol. 15, no. 4

831--835

EN

The paper presents results of a research on a possibility to apply the innovative, combined with activation of the binder, reclamation process of microwave-hardened moulding sands containing water-glass. The sandmix to be examined, prepared of high-silica sand and the selected water-glass grade 145, was subject to the following cyclical processing stages: mixing the components, compacting, microwave hardening, cooling-down, thermal loading the mould to 800 or 1200 °C, cooling-down to ambient temperature, knocking-out, mechanical dry and wet reclamation, refreshing. After each subsequent cycle of processing the sandmix, used and overheated to various degrees, determined was tensile and bending strength. Analysis of the obtained results indicates that it is possible to activate regenerate of used sandmix containing water-glass, hardened by microwave heating. However, effectiveness of activation in subsequent life cycles of the sandmix is significantly affected by temperature of the casting alloy poured to the mould.

15

Possibilities of Reclamation Microwave-Hardened Molding Sands with Water Glass

Stachowicz M., Granat K.

Archives of Metallurgy and Materials

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2014

|

Vol. 59, iss. 2

757--760

EN

The paper presents results of a research on identifying opportunities for effective reclamation of waste molding sand with water-glass, hardened by microwave heating. The molding sand applied in the tests was prepared with use of selected type 145 of sodium water-glass. The sand was sequentially processed by microwave hardening, cooling, thermal loading to 800°C, cooling to ambient temperature, crushing and mechanical reclamation. These stages create a closed processing loop. After each cycle, changes of tensile strength and bending strength were determined. Results of the study show that it is possible to activate surface of high-silica grains of waste foundry sand hardened with microwaves, provided that applied are appropriate processing parameters in successive operation cycles.

PL

W pracy przedstawiono wyniki badań nad określeniem możliwości prowadzenia skutecznej regeneracji zużytych mas formierskich ze szkłem wodnym utwardzanych w procesie nagrzewania mikrofalowego. Przeznaczoną do badań masę, sporządzoną z wybranym szkłem wodnym sodowym gatunku 145, poddawano kolejno procesom: utwardzania mikrofalowego, studzenia, obciążaniu termicznemu do temperatury 800°C. studzenia do temperatury otoczenia, rozkruszania i regeneracji mechanicznej. Opisane procesy tworzyły jeden zamknięty cykl przerobu zużytej masy. Po każdym kolejnym cyklu przerobu masy określano zmianę wytrzymałości na rozciąganie i zginanie. Analizując wyniki przeprowadzonych badań stwierdzono, że istnieje możliwość aktywacji regeneratu zużytej masy formierskiej ze szkłem wodnym, utwardzanej w procesie nagrzewania mikrofalowego, pod warunkiem zastosowania odpowiednich parametrów jej przygotowania, odbywającego się w kolejnych cyklach eksploatacji.

16

Analiza procesu suszenia papryki czerwonej w złożu fontannowym z nagrzewaniem mikrofalowym

Surma M., Peroń S., Jałoszyński K., Pasławska M., Stępień B.

Inżynieria Rolnicza

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2013

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R. 17, nr 4, t. 1

345--354

PL

Celem pracy było określenie możliwości zastosowania suszarki fontannowej z nagrzewaniem mikrofalowym surowca i uzyskanie informacji odnośnie przebiegu procesu i kinetyki ubytków wody oraz przedstawienie wpływu procesu suszenia na aktywność przeciwutleniającą i zawartość polifenoli w papryce czerwonej. W czasie suszenia papryki czerwonej stwierdzono, że wraz ze wzrostem mocy mikrofal wzrasta zawartość związków polifenolowych i aktywność przeciwutleniająca. Wyniki badań wskazują, że suszenie fontannowo-mikrofalowe pozwala uzyskać susz dobrej jakości i wpływa na poprawę jakości suszu z papryki w porównaniu z tradycyjnym suszeniem konwekcyjnym.

EN

The purpose of the study was to determine the applicability of spouted dryer heated by microwave material and obtain information about the process and the kinetics of water loss and of the effect of the drying process on antioxidant activity and polyphenol content of red pepper. During drying red peppers was found that with the increase of the microwave power is increased content of polyphenolic compounds and antioxidant activity. The results indicate that fountain-microwave drying ovens allows for drought of good quality and improving the quality of dried peppers over traditional convection drying.

17

Określenie możliwości zastosowania w procesach nagrzewania mikrofalowego oprzyrządowania odlewniczego z drewna

Granat K., Opyd B., Nowak D., Stachowicz M.

Archives of Foundry Engineering

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2013

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Vol. 13, iss. 1 spec.

135--138

PL

W pracy przedstawiono wyniki badań wstępnych nad możliwością zastosowania różnych gatunków drewna do budowy oprzyrządowania odlewniczego, przewidzianego przy procesie nagrzewania mikrofalowego mas formierskich i rdzeniowych. Badania podjęto w celu oceny tych materiałów z punktu widzenia kryterium transparentności dla promieniowania mikrofalowego. Pomiary przeprowadzono metodą perturbacyjną na stanowisku falowodowej wnęki rezonansowej, która umożliwia precyzyjne wyznaczenie tangensa kąta stratności oraz przenikalności dielektrycznej materiałów konstrukcyjnych. Wykazano, iż wszystkie wybrane gatunki drewna charakteryzują się zbliżonym współczynnikiem stratności, który determinuje możliwości ich zastosowania do budowy oprzyrządowania odlewniczego, przewidywanego do pracy w polu elektromagnetycznym.

EN

The paper presents the results of preliminary studies on the possibility of using different types of wood to construct foundry tooling, designed for microwave heating process of moulding and core sands. The study was undertaken to evaluate these materials from viewpoint of transparency criterion for microwave radiation. The measurements were carried out in a waveguide resonant cavity that permits precise determination permittivity and loss tangent by perturbation technique. It was demonstrated that all of the selected wood species are characterized by a similar loss factor that determines the possibility of their use in the construction of foundry tooling, intended for use in the electromagnetic field.

18

Badania gazów powstałych w procesie mikrofalowej utylizacji mas formierskich. Część 1

Samociuk B., Granat K., Nowak D., Stachowicz M., Pigiel M.

Archives of Foundry Engineering

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2013

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Vol. 13, iss. 1 spec.

159--162

PL

W artykule przedstawiono wyniki badań gazów, powstałych podczas utylizacji wybranych mas formierskich w reaktorze mikrofalowym, z punktu widzenia ich szkodliwości dla otoczenia. Metodą chromatografii gazowej analizowano gazy z pięciu mas formierskich (cztery ze spoiwem organicznym i jedną z nieorganicznym). Do utylizacji mas formierskich wykorzystano półprzemysłowy reaktor mikrofalowy. Analizując wyniki badań stwierdzono, że nastąpiło przekroczenie wartości największych dopuszczalnych stężeń gazów wytlewnych, określonych w Dyrektywie Unii Europejskiej wskaźnikiem szkodliwości dla otoczenia, jedynie w przypadku masy z żywicą fenolową Fenotec P439.

EN

In this work the influence of gases emitted from utilization of molding sand on the enviroment was studied. Five different molding sands were examined by gas chromatographic method. The analysis showed that the utilization of molding sands in the microwaves reactor found larger than allowable concentrations of gases only in the molding sand with phenolic resin Fenotec P439.

19

Microwave-assisted phase separation of alkali-borosilicates in the production of nanoporous glasses

Kullmann J., Enke D., Hahn T., Bauerschaefer U., Ledig L., Gai S., Bochmann A.

Optica Applicata

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2012

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Vol. 42, nr 2

255-263

EN

The influence of a hybrid thermal processing on the spinodal decomposition of sodium borosilicate glasses was investigated. The pore diameter of the resulting porous glasses is a function of the parameters of the thermal treatment. One result of this study was the inversion of the phase separation under preservation of the external shape of glass monoliths. Furthermore by using microwaves in addition to thermal radiation it was possible to generate temperature gradients in the samples and so gradients in pore size too. The glass templates were heated with microwaves in a tube furnace consisting of a resonant rectangular waveguide (TE103). Additionally the tube wall was heated by thermal radiation. The heating control was realized by steering the input power and the frequency of a 200 W semiconductor source. The regulation was performed with a HOMER 3-stub tuner, which simultaneously measured the impedance by reflected wave analysis and the actual template temperature with an IR-sensor. Various temperature-time courses of the hybrid furnace led to different pore size gradients. This was discussed by analyzing specific properties like mean pore diameter, surface area and pore volume. Further effects like the pore orientation and properties of the pore walls were determined by scanning electron microscopy and focused ion beam (FIB).

20

Leached phase-separated porous glasses as support material in liquid phase heterogeneous catalysis - a short review

Gallert T., Stolle A., Ondruschka B.

Optica Applicata

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2012

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Vol. 42, nr 2

245-254

EN

Leached phase-separated porous glasses are interesting support materials for heterogeneous catalysts utilized for cross-coupling reactions and hydrogenation reactions in the liquid phase. The option to construct tailor-made porous structures and shapes of the particles results in materials with interesting properties for catalysis, such as narrow pore size distribution or specific surface area. Loading of porous glasses with various metals by the wet-impregnation technique leads to active catalysts for widespread applications in organic synthesis. This article reviews the application of porous glass-based catalysts for the construction of new C-C bonds as well as for chemoselective hydrogenation under microwave-assisted or classical heating conditions.