Microbial Depolymerization of Epoxy Resins: A Novel Approach to a Complex Challenge

The objective of this project is evaluating the potential of microbes (fungi and bacteria) for the depolymerization of epoxy, aiming at the development of a circular management of natural resources for epoxy in a long-term prospective. For depolymerization, epoxy samples were incubated for 1, 3, 6 and 9 months in soil microcosms inoculated with Ganoderma adspersum. Contact angle data revealed a reduction in the hydrophobicity induced by the fungus. Environmental scanning electron microscopy on epoxy samples incubated for more than 3 years in microbiological water revealed abundant microbiota. This comprised microbes of different sizes and shapes. The fungi Trichoderma harzianum and Aspergillus calidoustus, as well as the bacteria Variovorax sp. and Methyloversatilis discipulorum, were isolated from this environment. Altogether, these results suggest that microbes are able to colonize epoxy surfaces and, most probably, also partially depolymerize them. This could open promising opportunities for the study of new metabolisms potentially able depolymerize epoxy materials.

Studying Ice with Environmental Scanning Electron Microscopy

Scanning electron microscopy (SEM) is a powerful imaging technique able to obtain astonishing images of the micro- and the nano-world. Unfortunately, the technique has been limited to vacuum conditions for many years. In the last decades, the ability to introduce water vapor into the SEM chamber and still collect the electrons by the detector, combined with the temperature control of the sample, has enabled the study of ice at nanoscale. Astounding images of hexagonal ice crystals suddenly became real. Since these first images were produced, several studies have been focusing their interest on using SEM to study ice nucleation, morphology, thaw, etc. In this paper, we want to review the different investigations devoted to this goal that have been conducted in recent years in the literature and the kind of information, beyond images, that was obtained. We focus our attention on studies trying to clarify the mechanisms of ice nucleation and those devoted to the study of ice dynamics. We also discuss these findings to elucidate the present and future of SEM applied to this field.

Integrative Model of Strategic Environmental Scanning based on Crises Management Approach

The aim of this study is to examine the way top managers scan environmental conditions to diagnose and interpret issues during periods of crisis. Despite each of these processes being widely and individually represented in the research literature, there is a lack of integrative models that examine their internal dynamics in-depth. In this study, structural equation modeling methodology (EQS 6.3) was applied to a sample of 120 top managers to examine how the cognitive orientation of scanning (rational vs. intuitive analysis of environment) may influence final issue categorizations. The overall findings of the current study show that strategic Environmental Scanning is conducted in UNRWA and has a stoical relation with crises management. This relation is weak and need to be strengthen especially during and after the crisis. The study suggest that strategic Environmental Scanning must be conducted permanently for external and internal environment to help UNRWA developing its strategic planning and to be to prepared to deal with potential crises in the future. Keywords: Strategic Environmental Scanning, Crises Management, UNRWA

ESEM Methodology for the Study of Ice Samples at Environmentally Relevant Subzero Temperatures: “Subzero ESEM”

Frozen aqueous solutions are an important subject of study in numerous scientific branches including the pharmaceutical and food industry, atmospheric chemistry, biology, and medicine. Here, we present an advanced environmental scanning electron microscope methodology for research of ice samples at environmentally relevant subzero temperatures, thus under conditions in which it is extremely challenging to maintain the thermodynamic equilibrium of the specimen. The methodology opens possibilities to observe intact ice samples at close to natural conditions. Based on the results of ANSYS software simulations of the surface temperature of a frozen sample, and knowledge of the partial pressure of water vapor in the gas mixture near the sample, we monitored static ice samples over several minutes. We also discuss possible artifacts that can arise from unwanted surface ice formation on, or ice sublimation from, the sample, as a consequence of shifting conditions away from thermodynamic equilibrium in the specimen chamber. To demonstrate the applicability of the methodology, we characterized how the true morphology of ice spheres containing salt changed upon aging and the morphology of ice spheres containing bovine serum albumin. After combining static observations with the dynamic process of ice sublimation from the sample, we can attain images with nanometer resolution.

The ice–vapour interface during growth and sublimation

We employed environmental scanning electron microscopy (ESEM) in low-humidity atmosphere to study the ice growth, coalescence of crystallites, polycrystalline film morphology, and sublimation, in the temperature range of −10 to −20 ∘C. First, individual ice crystals grow in the shape of micron-sized hexagonal columns with stable basal faces. Their coalescence during further growth results in substantial surface defects and forms thick polycrystalline films, consisting of large grains separated by grain boundaries. The latter are composed of 1 to 3 µm wide pores, which are attributed to the coalescence of defective crystallite surfaces. Sublimation of isolated crystals and of films is defect-driven, and grain boundaries play a decisive role. A scallop-like concave structure forms, limited by sharp ridges, which are terminated by nanoscale asperities. The motivation for this work is also to evaluate ESEM's ability to provide a clean and reproducible environment for future study of nucleation and growth on atmospherically relevant nucleators such as materials of biological origin and inorganic materials. Hence, extensive information regarding potential ESEM beam damage and effect of impurities are discussed.

Effect of Juglone against Pseudomonas syringae pv Actinidiae Planktonic Growth and Biofilm Formation

Pseudomonas syringaepv Actinidiae (P. syringae) is a common pathogen causing plant diseases. Limoli proved that its strong pathogenicity is closely related to biofilm state. As a natural bacteriostatic agent with broad-spectrum bactericidal properties, juglone can be used as a substitute for synthetic bacteriostatic agents. To explore the antibacterial mechanism, this study was carried out to examine the inhibitory effect of juglone on cell membrane destruction, abnormal oxidative stress, DNA insertion and biofilm prevention of P. syringae. Results showed that juglone at 20 μg/mL can act against planktogenic P. syringae (107 CFU/mL). Specially, the application of juglone significantly damaged the permeability and integrity of the cell membrane of P. syringae. Additionally, juglone caused abnormal intracellular oxidative stress, and also embedded in genomic DNA, which affected the normal function of the DNA of P. syringae. In addition, environmental scanning electron microscope (ESEM) and other methods showed that juglone effectively restricted the production of extracellular polymers, and then affected the formation of the cell membrane. This study provided a possibility for the development and utilization of natural juglone in plants, especially P. syringae.

Effect of Environmental Scanning on Performance of Chemelil Sugar Company in Kisumu County, Kenya

The environmental scanning been recognized as a vital management tool for well-performing companies. It includes collecting information within the organization's internal, industrial, and external environment that affect performance. The performance Chemelil Sugar Company in Kisumu County has been incompatible with the company's envisage strategic development plan. The company posted a loss of K.sh 821 million in the year June 2018, which is an increase compared to the loss of K.sh 767.25 million incurred in 2016. This formed the motive of the study to examine the effect of environmental scanning on the performance of Chemelil Sugar Company. The study was anchored on open system theory. The research adopted a descriptive research design. The target population was 60. The study focused on the heads of departments as the key respondents. The research instruments used in the study were questionnaires. The study conducted a census because the population size was small and for accuracy. The study applied purposive sampling technique. It was found that environmental scanning is positively and significantly related to performance. The results of regression analysis established that environmental scanning is positively and significantly related to performance (?=.840, p =.035). Thus, a unit increase in environmental scanning practices while holding all other factors constant, increases performance by 0.840 units. The study recommended that the company need to look at the internal analysis, industrial analysis and external analysis to maintain a higher performance level. The company can regularly analyze its industrial environment to determine its opportunities and threats using Porter's Five Factor analysis tool. In addition, it is recommended that the company need to regularly analyze its internal environmental factors to determine its strengths and weaknesses using SWOT as an analysis tool. Conducting environmental audit is necessary and the company needs to prepare plans to cope with dynamically changing environments. Keywords: Environmental scanning, performance, Chemelil Sugar Company, Kisumu County, Kenya

The Effect of Graphite Additives on Magnetization, Resistivity and Electrical Conductivity of Magnetorheological Plastomer

Common sensors in many applications are in the form of rigid devices that can react according to external stimuli. However, a magnetorheological plastomer (MRP) can offer a new type of sensing capability, as it is flexible in shape, soft, and responsive to an external magnetic field. In this study, graphite (Gr) particles are introduced into an MRP as an additive, to investigate the advantages of its electrical properties in MRPs, such as conductivity, which is absolutely required in a potential sensor. As a first step to achieve this, MRP samples containing carbonyl iron particles (CIPs) and various amounts of of Gr, from 0 to 10 wt.%, are prepared, and their magnetic-field-dependent electrical properties are experimentally evaluated. After the morphological aspect of Gr–MRP is characterized using environmental scanning electron microscopy (ESEM), the magnetic properties of MRP and Gr–MRP are evaluated via a vibrating sample magnetometer (VSM). The resistivities of the Gr–MRP samples are then tested under various applied magnetic flux densities, showing that the resistivity of Gr–MRP decreases with increasing of Gr content up to 10 wt.%. In addition, the electrical conductivity is tested using a test rig, showing that the conductivity increases as the amount of Gr additive increases, up to 10 wt.%. The conductivity of 10 wt.% Gr–MRP is found to be highest, at 178.06% higher than the Gr–MRP with 6 wt.%, for a magnetic flux density of 400 mT. It is observed that with the addition of Gr, the conductivity properties are improved with increases in the magnetic flux density, which could contribute to the potential usefulness of these materials as sensing detection devices.

Organic Matter and Pigments in the Wall Paintings of Me-Taw-Ya Temple in Bagan Valley, Myanmar

Pagán is an ancient city located in Myanmar that is renowned for the remains of about 4000 pagodas, stupas, temples and monasteries dating from the 11th to 13th centuries. Due to a magnitude 6.8 earthquake in 2016, more than 300 ancient buildings were seriously damaged. As a part of the post-earthquake emergency program, a diagnostic pilot project was carried out on Me-taw-ya temple wall paintings to acquire further information on the materials and on their state of conservation. This article presents our attempts at characterising the painting materials at Me-taw-ya temple using non-invasive portable energy dispersive X-ray fluorescence (ED-XRF), portable Raman spectroscopy and micro-invasive attenuated total reflectance—Fourier transform infrared spectroscopy (ATR-FTIR), micro-Raman spectroscopy (µ-Raman), gas chromatography-mass spectrometry (GC-MS), polarized light microscopy (PLM) and environmental scanning electron microscope—X-ray energy dispersive system (ESEM-EDS) investigations with the aim of identifying the composition of organic binders and pigments. The presence of a proteinaceous glue mixed with the lime-based plaster was ascertained and identified by GC-MS. In addition, this technique confirmed the occurrence of plant-derived gums as binders pointing to the a secco technique. Fe-based compounds, vermillion, carbon black and As-compounds were identified to have been incorporated in the palette of the murals.

Adapting the Environmental Scan for Gerontology Graduate Students’ Career Exploration

Environmental scanning is a process that provides organizations with information about their internal and external strengths, challenges, and opportunities. Although traditionally used in business and strategic planning, environmental scanning is now being utilized in health care to evaluate currently available programs and services, identify gaps in patient care or research, and make educational, organizational, and policy recommendations. The current study explores adapting the environmental scan for students enrolled in a gerontology graduate program as a tool to facilitate career exploration. Students learned about environmental scanning and were instructed to perform an environmental scan on an important issue, program, or service relevant to their overall career goals. Because students completed their environmental scan while enrolled in an Alzheimer’s Disease Management course, they were encouraged to factor in the increasing prevalence of Alzheimer’s disease into their project. Students’ environmental scan projects spanned several timely topics, including an evaluation of the services currently offered in assisted living facilities from the perspective of a geriatric social worker, a review of memory training interventions and a proposal for a new research study, and preliminary plans for opening an assisted living facility catering to older adults in the LGBTQ community that outlined financial considerations, staff training goals, and patient care plans. Completing the environmental scan project gave students an opportunity to investigate the current state of the career field they are planning to enter, and provided them with a product that they can build upon as they complete the graduate program and begin their careers.