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1

Impact of Passive Techniques on Thermal Behavior of Emergency Shelters

Hamdan Mohammad, Abd-Alhamid Fedaa, Dabbour Loai

Ecological Engineering & Environmental Technology

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2021

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Vol. 22, iss. 3

112--119

EN

Due to emergency situations, many people are living under degraded conditions as displaced persons and refugees. Unfortunately, shelters commonly used in humanitarian context do not ensure comfortable conditions for their occupants. This study investigates the impact of utilizing passive climatization techniques on the indoor thermal comfort of the occupants in refugee settlements under Jordan’s climate using the Design Builder software. Several passive techniques were simulated, including orientation, floor, wall and roof insulation, and natural ventilation. The simulation results indicated that the thermal comfort has improved when using the aforementioned techniques by 9.72% offering 23% comfort hours throughout the year.

2

Temperature, overcharge and short-circuit studies of batteries used in electric vehicles

Łebkowski A.

Przegląd Elektrotechniczny

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2017

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R. 93, nr 5

67--73

EN

The paper presents the results of temperature and short-circuit research of battery types most commonly used in electric vehicles. Basing on performed tests, the plots of changing internal resistance of lead-acid and lithium batteries are shown. On the basis of conducted short-circuit experiments of selected lithium based batteries of types used in electric vehicles, the risk of fire occurrence is made.

PL

W pracy przedstawiono wyniki badań temperaturowych oraz zwarciowych dla najczęściej stosowanych typów akumulatorów w pojazdach elektrycznych. W oparciu o przeprowadzone badania, przedstawiono przebiegi zmian rezystancji wewnętrznej akumulatorów kwasowych oraz litowych w zależności od temperatury. Na podstawie przeprowadzonych badań zwarciowych wybranych typów akumulatorów litowych stosowanych w pojazdach z napędem elektrycznym, dokonano oceny możliwości pojawienia się pożaru.

3

Morphological, Mechanical and Physio-chemical Performance of ortho-Cresol Epoxy Novolac Based Vinyl Ester Resin

Jaswal S., Gaur B.

Polish Journal of Chemical Technology

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2015

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Vol. 17, nr 3

1--7

EN

Vinyl ester resin (VEOCN) was prepared from o-cresol epoxy resin (EOCN) and methacrylic acid in the presence of triphenyl phosphine as catalyst and hydroquinone as inhibitor with acid value of ~ 7 mg of KOH per gram of solid. O-cresol based novolac resin (OCN), OCN based epoxy resin (EOCN) and VEOCN were characterized by Fourier transform infra red spectroscopy (FT-IR), 1H-NMR and 13C-NMR. The thermal and mechanical behavior of the samples prepared at 30°C from VEOCN using styrene and methyl-methacrylate respectively as reactive diluents, in the presence of benzoyl peroxide (2 phr) as initiator was studied using Differential Scanning Calorimetry (DSC), Thermogravimetric analysis (TGA) and Universal Testing Machine (UTM). Chemical resistance of above VER samples was also evaluated as a function of % weight loss and with the help of Scanning Electron Microscopy (SEM), upon immersing the VEOCN samples in different solutions for 90 days.

4

Effect of modified calcium carbonate on the thermal and mechanical properties of biodegradable poly(L-lactic acid)

Cai Y.-H., Zhang Y.-H., Zhao L.-S.

Polimery

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2015

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T. 60, nr 2

95--99

EN

Modified calcite CaCO3 (M-CaCO3) was synthesized from calcium nitrate, sodium carbonate, ethylene diamine tetraacetic acid and sodium dodecyl sulfate. Then, poly(L-lactic acid) (PLLA)/ M-CaCO3 composites were fabricated using melt blending and hot-press forming technologies. The effect of M-CaCO3 on the thermal and mechanical performance of PLLA was investigated. The results showed that the crystallization temperature and M-CaCO3 content significantly affected the crystallization of PLLA but the effect of M-CaCO3 on the crystallization of PLLA was very complicated. Compared to neat PLLA, 1 % M-CaCO3 decreased the t1/2 from 3999.4 s to 342.7 s at 100 °C. The melt index measurements indicated that a small amount of M-CaCO3 could block the fluidity of PLLA. However, the addition of a high content M-CaCO3 increased the fluidity of PLLA. The results of tensile strengths and elongation at break of PLLA/M-CaCO3 composites showed that both M-CaCO3 content and defective modification CaCO3 affected the mechanical performance of the PLLA/M-CaCO 3composites.

PL

Z zastosowaniem azotanu wapnia, węglanu sodu, kwasu etylenodiaminotetraoctowego idodecylosiarczanu sodu syntezowano modyfikowany kalcyt (M-CaCO3), a następnie mieszając składniki wstanie stopionym wytwarzano kompozyty poli(kwas L-mlekowy)/M-CaCO3. Badano zależność właściwości termicznych i mechanicznych wytworzonych kompozytów (z matrycą polilaktydową) od zawartości M-CaCO3.Wykazano, że istotny wpływ na krystalizację PLLA wywiera temperatura oraz zawartość modyfikowanego kalcytu. W temperaturze 100 °C czas połowicznej krystalizacji (t1/2) kompozytu z udziałem 1 % M-CaCO3 znacznie się zmniejszył (342,7 s) w porównaniu do wartość t1/2 czystego PLLA (3999,4 s). Pomiar masowego wskaźnika szybkości płynięcia (MFR) dowodzi, że dodatek modyfikowanego kalcytu (powyżej 3 %) do matrycy polilaktydowej wpływa na zwiększenie wartości MFR. Wyniki wytrzymałości na rozciąganie i wydłużenia przy zerwaniu kompozytów PLLA/M-CaCO3 wykazały, że zarówno zawartość węglanu wapnia, jak i jego modyfikacja wpływają na wytrzymałość mechaniczną wytworzonych kompozytów PLLA/M-CaCO3.

5

Influence of composition on the structure and properties of SrO-Sb2O3-P2O5 low-melting sealing glasses

Nie H., Zhang J., Qi Y., Wang Z., Lin H., Jiang S.

Materials Science Poland

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2015

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Vol. 33, No. 4

862--866

EN

SrO-Sb2O3-P2O5 glass system was prepared by high temperature melting method. The effects of Sb2O3 and P2O5 content on the structure, thermal behavior and chemical durability of the glasses were studied by infrared spectrometer, thermal dilatometer, differential thermal analyzer and constant temperature water bath heating. It can be concluded that the characteristic temperatures of the glasses increased firstly and then decreased with the increasing of Sb2O3 content, whereas the tendency of the coefficient of thermal expansion (CTE) varied inversely. The crystallization ability of the glasses was significantly increased and the water resistance was reduced for Sb2O3 content of 35 mol % and 40 mol %. The glasses with 20 mol %, 25 mol % and 30 mol % Sb2O3 showed better performance in every respect than the others and the glasses containing 25 mol % Sb2O3, characterized by the best performance, can be chosen as host glasses for further research.

6

Splat formation and degradation of hydroxyapatite during plasma spraying process

Mittal M., Nath S., Prakash S.

Advances in Materials Science

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2011

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Vol. 11, nr 2(28)

26-36

EN

Plasma spraying is most used thermal spray process for coating of bioceramic and bioinert materials. It is line of sight technique, easy to use and inexpensive as compared to other processes used for coatings. The main disadvantage of this technique for coating hydroxyapatite (HA) is that due to high temperature of plasma (of the order of 16000°C) HA tends to degrade into amorphous calcium phosphates. These amorphous phases are not desirable and have a tendency to dissolve in body environment. In this article an attempt has been made to understand the plasma spraying process for coating of hydroxyapatite.

7

Synthesis and characterization of cross-linked poly(esterurethane)s for elastomeric bearings

Oprea S.

Polimery

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2010

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T. 55, nr 9

634-640

EN

Cross-linked poly(esterurethane) elastomers (PEURs) have been synthesized in a two-step synthesis. In the first step poly(ethylene adipate) diol was reacted with 4,4'-diphenyl-methane diisocyanate, then the obtained prepolymers were chain extended with bifunctional precursor (1,3-propane diol or 1,5-pentane diol) chains and a trifunctional cross-linker (glycerine) at stoichiometric ratios, resulting in a series of cross-linked products with various hard segment (HS) of various structure and content. Their thermal and mechanical properties were determined. Due to phase separation and cross-linked hard segments, propane diol based polyurethane exhibited high mechanical properties. The replacement of propane diol with pentane diol had a negative effect on these mechanical properties. The described cross-linked PEURs possessed strain/shape recovery properties.

PL

Usieciowane elastomeryczne poli(estrouretany) (PEUR) otrzymywano w wyniku dwuetapowego procesu obejmującego syntezę prepolimeru w reakcji diolu na podstawie poli(adypinianu etylenu) (PEA, c. cz. 2000) z 4,4'-diizocyjanodifenylometanem (MDI) i następnie przedłużanie łańcucha tego prepolimeru z zastosowaniem 1,3-propanodiolu (D) bądź 1,5-pentanodiolu (PD) z jednoczesnym sieciowaniem przy użyciu gliceryny (Gly) (tabela 1). Uzyskano w ten sposób próbki PEUR (D1-D3 oraz PD1-PD3) różniące się zawartością oraz budową segmentów "twardych" i twardością (tabela 2). Scharakteryzowano widma IR tych produktów (rys. 2 i 3), ich właściwości cieplne (rys. 4, tabela 3) oraz przebieg krzywych rozciągania (rys. 5). Szczegółowo przeanalizowano zachowanie się PEUR w próbach odkształcania pod wpływem sił ścinających (warunki quasi-statyczne, amplituda 5 lub 50 kN, rys. 7-10). Zastąpienie D przez PD znacznie pogarsza właściwości mechaniczne produktów. Opisywane usieciowanie PEUR poddane działaniu naprężeń odkształcających mają zdolność powrotu do pierwotnego kształtu.

8

Synthesis and Spectroscopic Investigation of Binuclear Copper(II), Cobalt(II), Nickel(II), Manganese(II), Zinc(II) and Cadmium(II) Complexes Derived from N,N'-Bis(2-carboxylphenyl)-2,6-pyridinedicarboxamide

Gudasi K., Patil S., Vadavi R., Shenoy R., Patil M.

Polish Journal of Chemistry

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2006

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Vol. 80, nr 2

247-257

EN

A new amide ligand, N,N'-bis(2-carboxylphenyl)-2,6-pyridinedicarboxamide (BCPD), formed by the condensation of 2,6-pyridine dicarbonyldichloride with 2-aminobenzoic acid has been structurally characterized. Binuclear Cu(II), Co(II), Ni(II), Mn(II), Zn(II) and Cd(II) complexes have been synthesized for the first time. Their structures have been elucidated on the basis of elemental analyses, conductance measurement, magnetic moment, spectral (IR,NMR,UV-Vis, EPR and FAB) and thermal studies. Infrared spectra of the complexes indicate the participation of uncharged amide oxygen atoms, pyridine nitrogen and carboxylic acid groups in a chelating bidentate fashion via deprotonation. The studies reveal that both the metal ions are present in an octahedral environment. Non-electrolytic nature of the complexes is evidenced by their low conductance data. X-band EPR spectra of the binuclear Cu(II) and Mn(II) complexes in polycrystalline state at room temperature and liquid nitrogen temperature were recorded and their salient features are reported. Thermal stabilities of the Zn(II) and Cd(II) complexes have been studied.