The impact of high-density polyethylene materials on microbiological purity in the process of storing and preserving textiles

2016 ◽  
Vol 87 (17) ◽  
pp. 2076-2088 ◽  
Author(s):  
Tomasz Lech
Keyword(s):  
High Density Polyethylene ◽  
Good Condition ◽  
Natural Fibers ◽  
Storage Conditions ◽  
High Density ◽  
Cellulolytic Enzymes ◽  
Microbiological Analysis ◽  
The Impact ◽  
Long Term Preservation

Textiles made of natural fibers, both contemporary and historical, are at constant risk of degradation caused by, among others, microbial enzymatic activity. Fungi, bacteria, or actinomycetes are capable of producing proteolytic and cellulolytic enzymes, enabling microbial growth on textiles and leading to their decay. Ensuring proper storage conditions, including the usage of protective materials, allows long-term preservation of historical textiles in a good condition. These studies involved a broad microbiological analysis in order to verify whether high-density polyethylene (HDPE) materials can protect historical textiles during their storage. The results demonstrate interesting differences in microbial counts between washed textiles stored without HDPE covers and those stored in such covers; the latter presented considerably higher counts of microorganisms. However, when textiles had previously been sterilized, HDPE covers helped maintain appropriate microbiological purity. A considerable portion of historical textile collections, particularly exceptional silk liturgical vestments or burial garments, are kept by church institutions and stored in sacristies, treasuries, or other church rooms. The specificity of these places, both cultural and related to the age of the buildings themselves, makes them exceptional environments for storing textiles. To date, these places have rarely been researched, particularly in microbiological aspects. The analysis recounted below encompasses qualitative and quantitative assessment of fungi and bacteria present in the air of the treasury of the Wawel Royal Cathedral in Krakow, Poland, as well as the analysis of their destructive potential.

Evaluation of the Aging Behavior of High Density Polyethylene in Thermal Oxidative Environment by Principal Component Analysis

2017 ◽  
Vol 727 ◽  
pp. 447-449 ◽  
Author(s):  
Jun Dai ◽  
Hua Yan ◽  
Jian Jian Yang ◽  
Jun Jun Guo
Keyword(s):  
Principal Component Analysis ◽  
Impact Strength ◽  
High Density Polyethylene ◽  
Tensile Modulus ◽  
Principal Component ◽  
Component Analysis ◽  
High Density ◽  
Aging Behavior ◽  
Data Set ◽  
The Impact

To evaluate the aging behavior of high density polyethylene (HDPE) under an artificial accelerated environment, principal component analysis (PCA) was used to establish a non-dimensional expression Z from a data set of multiple degradation parameters of HDPE. In this study, HDPE samples were exposed to the accelerated thermal oxidative environment for different time intervals up to 64 days. The results showed that the combined evaluating parameter Z was characterized by three-stage changes. The combined evaluating parameter Z increased quickly in the first 16 days of exposure and then leveled off. After 40 days, it began to increase again. Among the 10 degradation parameters, branching degree, carbonyl index and hydroxyl index are strongly associated. The tensile modulus is highly correlated with the impact strength. The tensile strength, tensile modulus and impact strength are negatively correlated with the crystallinity.

Effect of inorganic nanofillers on the impact behavior and fracture probability of industrial high-density polyethylene nanocomposite

2017 ◽  
Vol 52 (18) ◽  
pp. 2431-2442 ◽  
Author(s):  
Harun Sepet ◽  
Necmettin Tarakcioglu ◽  
RDK Misra
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Density Polyethylene ◽  
Fracture Probability ◽  
High Density ◽  
Impact Behavior ◽  
Inorganic Filler ◽  
Melt Mixing ◽  
The Impact ◽  
Scanning Electron

The main purpose of this work is to study how the morphology of nanofillers and dispersion and distribution level of inorganic nanofiller influence the impact behavior and fracture probability of inorganic filler filled industrial high-density polyethylene nanocomposites. For this study, nanoclay and nano-CaCO3 fillers–high-density polyethylene mixings (0, 1, 3, 5 wt.% high-density polyethylene) was prepared by melt-mixing method using a compounder system. The impact behavior was examined by charpy impact test, scanning electron microscopy, and probability theory and statistics. The level of the dispersion was characterized with scanning electron microscopy energy dispersive X-ray spectroscopy analysis. The results showed rather good dispersion of both of inorganic nanofiller, with a mixture of exfoliated and confined morphology. The results indicated that the impact strength of the industrial nanocomposite decreased with the increase of inorganic particulate content. The impact reliability of the industrial nanocomposites depends on the type of nanofillers and their dispersion and distribution in the matrix.

scholarly journals Managing Moholy : László Moholy-Nagy's photograms in the collections of the Art Institute of Chicago and George Eastman House

2021 ◽  
Author(s):  
D. Anne Maryanski
Keyword(s):  
Detailed Analysis ◽  
Storage Conditions ◽  
Experimental Techniques ◽  
Collections Management ◽  
Policies And Procedures ◽  
Unique Nature ◽  
Entire Career ◽  
Long Term Preservation

The Art Institute of Chicago (AIC) and George Eastman House International Museum of Photography and Film (GEH) have acquired substantial collections of László Moholy-Nagy's work, spanning his entire career. Using four photograms by Moholy-Nagy, two from each institution, as representative examples, this thesis examines how the AIC and GEH have dealt with his work through an examination of the acquisition, exhibition, publication, preservation, and conservation of his photographs. The unique nature of Moholy-Nagy's photograms, coupled with the myriad experimental techniques he employed in their production, has necessitated that the AIC and GEH establish policies and procedures for the care and long-term preservation of photographic objects of this nature, through the development and implementation of exhibition and loan standards as well as highly monitored storage conditions. This thesis includes an overview of the museums, a detailed analysis of each photogram, and a discussion of the collections management concerns that these objects raise.

scholarly journals Stratigraphy of the Anthropocene

2011 ◽  
Vol 369 (1938) ◽  
pp. 1036-1055 ◽  
Author(s):  
Jan Zalasiewicz ◽  
Mark Williams ◽  
Richard Fortey ◽  
Alan Smith ◽  
Tiffany L. Barry ◽  
...  
Keyword(s):  
Sediment Flux ◽  
Relative Timing ◽  
Sequence Stratigraphic ◽  
The Earth ◽  
Time Space ◽  
Marine Realm ◽  
Physical And Chemical ◽  
The Impact ◽  
Long Term Preservation

The Anthropocene, an informal term used to signal the impact of collective human activity on biological, physical and chemical processes on the Earth system, is assessed using stratigraphic criteria. It is complex in time, space and process, and may be considered in terms of the scale, relative timing, duration and novelty of its various phenomena. The lithostratigraphic signal includes both direct components, such as urban constructions and man-made deposits, and indirect ones, such as sediment flux changes. Already widespread, these are producing a significant ‘event layer’, locally with considerable long-term preservation potential. Chemostratigraphic signals include new organic compounds, but are likely to be dominated by the effects of CO 2 release, particularly via acidification in the marine realm, and man-made radionuclides. The sequence stratigraphic signal is negligible to date, but may become geologically significant over centennial/millennial time scales. The rapidly growing biostratigraphic signal includes geologically novel aspects (the scale of globally transferred species) and geologically will have permanent effects.

scholarly journals Impact of Polymer Binders on the Structure of Highly Filled Zirconia Feedstocks

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2247
Author(s):  
Claire Delaroa ◽  
René Fulchiron ◽  
Eric Lintingre ◽  
Zoé Buniazet ◽  
Philippe Cassagnau
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
High Density Polyethylene ◽  
Mercury Porosimetry ◽  
High Density ◽  
Organic Binder ◽  
Molten State ◽  
Homogeneous Dispersion ◽  
The Impact

The impact of polypropylene and high-density polyethylene backbone binders on the structure of organic matrix, feedstock, and ceramic parts is investigated in terms of morphology in this paper. The miscibility of wax with polyethylene and polypropylene is investigated in the molten state via a rheological study, revealing wax full miscibility with high-density polyethylene and restricted miscibility with polypropylene. Mercury porosimetry measurements realized after wax extraction allow the characterization of wax dispersion in both neat organic blends and zirconia filled feedstocks. Miscibility differences in the molten state highly impact wax dispersion in backbone polymers after cooling: wax is preferentially located in polyethylene phase, while it is easily segregated from polypropylene phase, leading to the creation of large cracks during solvent debinding. The use of a polyethylene/polypropylene ratio higher than 70/30 hinders wax segregation and favors its homogeneous dispersion in organic binder. As zirconia is added to organic blends containing polyethylene, polypropylene, and wax, the pore size distribution created by wax extraction is shifted towards smaller pores. Above zirconia percolation at 40 vol%, the pore size distribution becomes sharp attesting of wax homogeneous dispersion. As the PP content in the organic binder decreases from 100% to 0%, the pore size distribution is reduced of 30%, leading to higher densification ability. In order to ensure a maximal densification of the final ceramic, polyethylene/polypropylene ratios with a minimum content of 70% of high-density polyethylene should be employed.

Effect of Date Palm Fiber Loadings on the Mechanical Properties of High Density Polyethylene/Date Palm Fiber Composites

2018 ◽  
Vol 773 ◽  
pp. 94-99 ◽  
Author(s):  
Venitalitya Augustia ◽  
Achmad Chafidz ◽  
Lucky Setyaningsih ◽  
Muhammad Rizal ◽  
Mujtahid Kaavessina ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Water Absorption ◽  
High Density Polyethylene ◽  
Date Palm ◽  
Agricultural Waste ◽  
Natural Fibers ◽  
High Density ◽  
Palm Fiber ◽  
Test Result

The trend of using natural fibers as green filler in the fabrication of polymer composites is increasing. One of these natural fibers is date palm fiber (DPF). Date palm fiber is considered as agricultural waste in certain areas, such as Middle East countries. Therefore, the utilization of this fiber in the composites fabrication is an interesting topic of research. In the current study, composites were prepared by melt blending DPF with high density polyethylene (HDPE). Five different DPF loadings were studied (i.e. 0, 5, 10, 20, 30 wt%). The effect of the DPF loadings on the mechanical properties and water absorption behavior of the composites were investigated. The tensile test result showed that tensile strengths of all the composites samples were all higher than the neat HDPE with the maximum improvement was achieved at the DPF loading of 5 wt% (i.e. DFC-5), which was about 19.23 MPa (138% higher than the neat HDPE). Whereas, the flexural test result showed that the flexural strength of the composites slightly increased compared to that of the neat HDPE only until 5 wt% DPF loading (i.e. DFC-5). Afterward, the flexural strength of the DFC-10 was equal to that of the neat HDPE, and decreasing with further increase of DPF loadings. Additionally, the water absorption test result showed that the water absorption rate and uptake of water (at equilibrium) increased with the increase of DPF loading.

Influence of Thermal Ratcheting on the Creep and Mechanical Properties of High-Density Polyethylene

2019 ◽  
Vol 141 (4) ◽  
Author(s):  
Rahul Palaniappan Kanthabhabha Jeya ◽  
Abdel-Hakim Bouzid
Keyword(s):  
Creep Strain ◽  
High Density Polyethylene ◽  
Coefficient Of Thermal Expansion ◽  
Creep Property ◽  
High Density ◽  
Steady Creep ◽  
Thermal Cycles ◽  
Ratcheting Strain ◽  
Thermal Ratcheting ◽  
The Impact

Abstract The objective of this research is to describe the consequence of thermal ratcheting on the long-term creep property of the high-density polyethylene (HDPE) material. The thermal ratcheting phenomenon increases significantly the creep strain of HDPE. The magnitude of the creep strain of HDPE increases by 8% after just 20 thermal cycles between 28 and 50 °C. The creep modulus, which is inversely proportional to the creep strain, depletes further under thermal ratcheting. Both the properties change significantly with the number of thermal cycles. The coefficient of thermal expansion (CTE) of HDPE varies with the applied compressive load, with successive thermal cycles, and with the thermal ratcheting temperature. The impact of thermal ratcheting diminishes with an increase in initial steady creep exposure time period, but still the magnitude cumulative deformation induced is noteworthy. The magnitude of growth in creep strain drops from 8% to 2.4% when thermal ratcheting is performed after 1 and 45 days of steady creep, respectively. There is a notable change in the thickness of the material with each heating and cooling cycle even after 45 days of creep; however, the thermal ratcheting strain value drops by 80% in comparison with the thermal ratcheting strain after 1 day of creep and under similar test conditions.

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