Scanning Electron Microscopy

Scanning electron microscopy (SEM; this acronym is used for both the instrument itself and the technique) has been broadly used in archaeology for over four decades.  The SEM is capable of two basic functions: imaging and providing compositional information.  Consequently, it has been utilized for nearly every archaeological application in which one wishes to examine magnified images of a specimen and/or determine its composition on a microscopic scale, everything from determining the raw-material sources of stone tools to examining the five-millennia-old skin of Ötzi the Iceman.

... As determined by EDS, the predominant elements in the fly ash samples were silicon, aluminum,iron, calcium and oxygen in various compounds. ... [16] suggested that the iron in the alumino-silicate glassy phase in fly ash is the source of bioavailable iron in urban areas. ...

Nowadays, the cellulosic ethanol is an important alternative way to many liquid biofuels using renewable biomass rich in polysaccharides. To be used as feedstock for ethanol production, the bagasse needs to be pretreated in order to expose its main constitutive. The present work proposes the use of different pretreatment processes to better expose the cellulose for hydrolysis and fermentation. In the present paper the sugarcane bagasse was submitted to a hydrothermal pretreatment followed by atmospheric pressure plasmas (APPs). An RF microplasma torch was employed as APPs in Ar and Ar/O2 mixing. The bagasse was treated in discharge and post-discharge regions. The position and time of treatment was varied as well as the gas mixture. The quantity of polysaccharides was determined by using high performance liquid chromatography. It was observed the release of a fraction of the hemicelluloses in the sugarcane bagasse. Modifications in the surface of the sugarcane fibers were monitored by employing scanning electron microscopy.

The South Caucasus was a major center of metal production in the Late Bronze and Early Iron Ages. Nowhere is this more clear than in the hills and mountains in the southeastern Black Sea region (ancient Colchis), where exceptionally large numbers of metal production sites have been found. Chemical and microscopic analysis of slagged technical ceramics at these sites illuminates several aspects of both raw copper and tin bronze alloy production. Copper ores were smelted in a complex multi-stage process designed to extract metal from sulfide ores. Technical ceramics served as containers for a range of different reactions, from the first phase of smelting, in which the copper sulfides were likely consolidated into a matte, though later stages of matte processing and metal copper production in smaller crucibles. In addition, a single crucible fragment, recovered from a late 2nd millennium BC slag heap, demonstrates that tin bronze was created by the direct addition of cassiterite tin ore, probably of alluvial origin, to metallic copper. The crucible's context, the use of cassiterite ore rather than tin metal, and a review of local geology suggests that the tin used in this crucible came from nearby, with the most likely source being the Vakijvari and Bzhuzhi gorges roughly 10-15 km away. While a single fragment does not speak to the regularity of this practice, at the very least it raises the possibility that the Colchian bronze industry was based on local rather than imported tin.

Transmucosal nasal delivery is a promising drug delivery
option where common drug administrations (e.g., intravenous,
intramuscular, or oral) are inapplicable. Recently, it has been
shown that many drugs have better bioavailability by nasal
route than by oral route. This has been attributed to rich
vasculature and a highly permeable structure of the nasal
mucosa coupled with avoidance of hepatic first-pass
elimination, gut wall metabolism and/or destruction in the
gastrointestinal tract. The physiology of the nose presents
obstacles, but offers a promising route for non-invasive
systemic delivery of numerous therapies and debatably drug
delivery route to the brain. To overcoming problems in nasal
drug delivery requires deep understanding of the various
factors affecting nasal delivery. Thus present review focuses on
various aspects of nasal drug delivery with special emphasis to
factors affecting nasal drug administration.

Hürzeler MB, Zuhr O, Schupbach P, Rebele SF, Emmanouilidis N, Fickl S. The socket-shield technique: a proof-of-principle report. J Clin Periodontol 2010; 37: 855–862. doi: 10.1111/j.1600-051X.2010.01595.x.Hürzeler MB, Zuhr O, Schupbach P, Rebele SF, Emmanouilidis N, Fickl S. The socket-shield technique: a proof-of-principle report. J Clin Periodontol 2010; 37: 855–862. doi: 10.1111/j.1600-051X.2010.01595.x.AbstractAim: Clinical studies have suggested that retaining roots of hopeless teeth may avoid tissue alterations after tooth extraction. Therefore, the objective of this proof-of-principle experiment was to histologically assess a partial root retention (socket-shield technique) in combination with immediate implant placement.Material and Methods: In one beagle dog, the third and fourth mandibular pre-molar were hemisected and the buccal fragment of the distal root was retained approximately 1 mm coronal to the buccal bone plate. Following application of enamel matrix derivate, a titanium implant was placed lingual to that tooth fragment either with or without contact to the buccal tooth fragment and a healing abutment was connected. Four months after implant placement, histological evaluation, and backscatter scanning electron microscopy were performed.Results: All four implants were osseointegrated without any histologic inflammatory reaction and the tooth fragment was devoid of any resorptional processes. On the buccal side, the tooth fragment was attached to the buccal bone plate by a physiologic periodontal ligament. On the lingual side of the fragment, newly formed cementum could be detected. In the areas where the implant was placed into the fragment, newly formed cementum was demonstrated directly on the implant surface.Conclusions: Retaining the buccal aspect of the root during implant placement does not appear to interfere with osseointegration and may be beneficial in preserving the buccal bone plate.Aim: Clinical studies have suggested that retaining roots of hopeless teeth may avoid tissue alterations after tooth extraction. Therefore, the objective of this proof-of-principle experiment was to histologically assess a partial root retention (socket-shield technique) in combination with immediate implant placement.Material and Methods: In one beagle dog, the third and fourth mandibular pre-molar were hemisected and the buccal fragment of the distal root was retained approximately 1 mm coronal to the buccal bone plate. Following application of enamel matrix derivate, a titanium implant was placed lingual to that tooth fragment either with or without contact to the buccal tooth fragment and a healing abutment was connected. Four months after implant placement, histological evaluation, and backscatter scanning electron microscopy were performed.Results: All four implants were osseointegrated without any histologic inflammatory reaction and the tooth fragment was devoid of any resorptional processes. On the buccal side, the tooth fragment was attached to the buccal bone plate by a physiologic periodontal ligament. On the lingual side of the fragment, newly formed cementum could be detected. In the areas where the implant was placed into the fragment, newly formed cementum was demonstrated directly on the implant surface.Conclusions: Retaining the buccal aspect of the root during implant placement does not appear to interfere with osseointegration and may be beneficial in preserving the buccal bone plate.

Doxorubicin (DOX) is a chemotherapeutic agent used for treatment of different cancers and its clinical usage is hindered by the oxidative injury-related cardiotoxicity. This work aims to declare if the harmful effects of DOX on heart can be alleviated with the use of Coenzyme Q10 (CoQ10) or L-carnitine. The study was performed on seventy two female Wistar albino rats divided into six groups, 12 animals each: Control group; DOX group (10 mg/kg); CoQ10 group (200 mg/kg); L-carnitine group (100 mg/kg); DOX + CoQ10 group; DOX + L-carnitine group. CoQ10 and L-carnitine treatment orally started 5 days before a single dose of 10 mg/kg DOX that injected intraperitoneally (IP) then the treatment continued for 10 days. At the end of the study, serum biochemical parameters of cardiac damage, oxidative stress indices, and histopatho-logical changes were investigated. CoQ10 or L-carnitine showed a noticeable effects in improving cardiac functions evidenced reducing serum enzymes as serum interleukin-1 beta (IL-1), tumor necrosis factor alpha (TNF-), leptin, lactate dehydrogenase (LDH), Cardiotrophin-1, Troponin-I and Troponin-T. Also, alleviate oxidative stress, decrease of cardiac Malondialdehyde (MDA), Nitric oxide (NO) and restoring cardiac reduced glutathione levels to normal levels. Both corrected the cardiac alterations histologically and ultrastructurally. With a visible improvements in-SMA, vimentin and eNOS immunohistochemical markers. CoQ10 or L-carnitine supplementation improves the functional and structural integrity of the myocardium.

Hydrogen embrittlement is a common, dangerous, and poorly understood cause of failure in many metal alloys. In practice, it
is observed that different types of damage to industrial components have been tied to the presence and localization of hydrogen in metals. Many efforts have been made at understanding the effects of hydrogen on materials, resulting in an abundance of theoretical models and papers. However, a fully developed and practically-applicable predictive physical model still does not exist industrially for predicting and preventing hydrogen embrittlement. The connection of microstructure-based behaviors of materials and effects on the macroscopic measurable characteristics (stress levels, hardness, strength, and impact toughness) is of the utmost importance to achieve a unified model for hydrogen embrittlement. This paper gives an overview of the application of a model for structural integrity analysis of boiler tubes made of
plain carbon steel exposed during operation to a local corrosion process and multiple hydrogen assisted degradation processes: hydrogen embrittlement and high-temperature hydrogen attack. The model is based on the correlation of mechanical properties to scanning electron microscopy fractography analysis of fracture surfaces in the presence of simultaneously active hydrogen embrittlement micromechanisms. The proposed model is practical for use as a predictive maintenance in power plants, as it is based on the use of standard macro-mechanical tests.

BACKGROUND:
In spite of its indusrial usefulness and varied daily uses, lead (Pb) pollution is a widespread ecological problem that faces the humans in the 21th century. Pb was found to produces a wide range of toxic effects including neurotoxicity especially to the developing and young offspring. Recently, the utilization of herbal plants has received a significant attention where there has been rising awareness in their therapeutic use; among these is the garlic.
AIM OF THE WORK:
In light of the above, the current study is designed experimentally in female pregnant rats in order to investigate the beneficial role of garlic extract in the protection from the maternal and fetal cerebellar damage that produced by administration of different doses of Pb during pregnancy.
MATERIALS AND METHODS:
Positively pregnant female rats were divided into five groups; one control group, two Pb-treated groups (exposed to 160 and 320 mg/kg b.wt. of Pb, respectively) and two groups treated with both Pb and garlic (exposed to Pb as previous groups together with 250 mg/ kg b.wt. /day of garlic extract). Treatments started from day 1 till day 20 of pregnancy, where the mother rats of different experimental groups were sacrified to obtain the fetuses. Pb level in the maternal nd fetal blood and cerebellum was estimated by spectrophotometry. Specimens of the cerebellum of different mother and fetal groups were processed to histological and immunohistochemical staining for microscopic examination.
RESULTS:
The results showed that administration of Pb to pregnant rats resulted in a dose-dependent toxicity for both mothers and fetuses in the form of decrease of maternal weight gain, placental and fetal weights, brain weight and diminished fetal growth parameters, which were prominent in rat's group treated with larger dose of Pb. In Pb-treated rats, Pb level in blood and cerebellum was high when compared to the control. The histopathological examination of the cerebellum of treated dams and fetuses showed marked alterations mainly in the form of Purkinje cell degeneration and lack of deveopmet of fetal cerebellum. Co-treatment of garlic extract along with Pb resulted in a significant decrease in Pb levels as compared with those treated with Pb alone with improvement of the histopathological changes.
CONCLUSIONS:
This study was useful in evaluating the hazardous effects of uncontrolled use of Pb in general and in assessing the developmental and neurotoxicity of fetuses due to exposure during pregnancy in particular. Co-administration of garlic has beneficial effects in amelioration of Pb-induced neurotoxicity and reversing the histopathological changes of the cerebellum of mother rats and fetuses.
KEYWORDS:
garlic; glial fibrillary acidic protein; lead; purkinje cells

Many efforts have been made to understand the effects of hydrogen on steels, resulting in an abundance of theoretical models and papers. However, a fully developed and practically applicable predictive physical model still does not exist industrially for predicting and preventing hydrogen damage. In practice, it is observed that different types of damages to industrial boiler components have been associated with the presence and localization of hydrogen in metals. In this paper, a damaged boiler tube made of grade 20 – St.20 (or 20G, equivalent to AISI 1020) was investigated. The experimental research was conducted in two distinctive phases: failure analysis of the boiler evaporator tube sample and subsequent postmortem analysis of the viable hydrogen embrittlement mechanisms (HE) in St.20 steel. Numerous tested samples were cut out from the boiler tubes of fossil fuel power plant, damaged due to high temperature hydrogen attack (HTHA) during service, as a result of the development of hydrogen-induced corrosion process. Samples were prepared for the chemical composition analysis, tube wall thickness measurement, tensile testing, hardness measurement, impact strength testing (on in-strumented Charpy machine), analysis of the chemical composition of corrosion products – deposit and the microstructural characterization by optical and scanning electron microscopy – SEM/EDX. The HTHA damage mechanism is a primary cause of boiler tube fracture. Based on the multi-scale special model, applied in subsequent postmortem investigations, the results indicate a simultaneous action of the hydrogen-enhanced decohesion (HEDE) and hydrogen-enhanced localized plasticity (HELP) mechanisms of HE, depending on the local concentration of hydrogen in investigated steel. The model is based on the correlation of mechanical properties to the SEM fractography analysis of fracture surfaces.

‘Ideal’ Versus ‘Possible’ in Field of Scientific Investigation Nowadays

Marcia Rizzo, Professor of Superior Conservation Course / conservator,
PUC- SP Pontifical Catholic University of São Paulo, Brazil

The aim of this paper is to discuss the relationship between the
“ideal” and the “possible” in the field of scientific research applied
to conservation of cultural heritage. The scientific research on
works of art must be done very carefully. The non-destructive
analysis methods are preferred to the destructive. First of all the
question and the reason of this question must be clear. Then it’s
necessary to know that methods of analysis can give the expected
response, which of these methods are available and which are
possible to be applied to works of art. It’s necessary to think also
about whether the analysis will be done in situ or if the work
must be carried. If with withdrawal of samples or not. In other
words it is necessary to create a strategy and approach procedure.
However, as is known, it’s not always possible to use the ideal
procedure with all equipment and analysis desired. Sometimes the
restriction is imposed by the artwork itself, because of the size,
location, condition, etc.; other, by the project, deadlines, budgets,
resources, availability of equipment, materials, etc. It takes a very
broad knowledge in the scientific area to make the most appropriate
decisions.
To illustrate this, two examples will be discussed here: the
research done in the paintings on the ceiling of the Carmelite
church in SP, which used destructive methods, and the research
done in the oil painting Annunciation, which used non-destructive
methods. The paintings of Carmo Church in Sao Paulo, carried in
the eighteenth century and attributed to the great Baroque artist
Frei Jesuíno of Mount Carmel, had refinish on funds and central
figures. Original paints, as well as the subsequent interventions
were investigated scientifically through diverse methods based on
the use of complementary techniques and cross link of results, for
the purpose of timing layers and propose treatment of restoration.
The original materials and those added later were physicochemical
and analytically characterized. For this purpose samples
of repainting and micro-samples from the original painting were
taken. The following techniques were employed: cross-section of
the pictorial layer; microscopic observation by binocular microscope
and scanning electron microscopy with energy dispersive
analyzer of X-ray the Annunciation painting made by Swedish artist Fredrik Westin (1782-1862), presented refinishing in several
areas. It was possible to identify these areas through observation
with UV radiation. The original pigments and the paints added
later were characterized with a portable fluorescence X-rays Tracer
III-SD da Bruker. In this case it was not necessary to remove
samples. Whenever possible, the ideal is to make the scientific
investigation of works of art with non-destructive methods in situ
analysis, analyzing the front of pictorial layer; however sometimes
it is necessary to observe directly the overlapping strata. And in
these cases the withdrawal of samples could be required. It is
important to assess whether the response I intend to get justified
the use of a destructive method of analysis. The investigation
made at Carmo’s Church contributed to reveal a very important
painting and also part of Brazilian history.

Scanning electron microscopy (SEM) has occasionally been used by anthropologists and forensic scientists to look at morphological characteristics that certain implements leave on bone. However, few studies have addressed techniques or protocols for assessing quantitative differences between tool marks on bone made by different bladed implements. In this study, the statistical variation in cut mark width was examined between control and test samples on bone using a scalpel blade, paring knife, and kitchen utility knife. Statistically significant differences (p < .0005) were found between cut marks made by the same knife under control and test conditions for all three knife types used in the study. When the control sample and test samples were examined individually for differences in mean variation between knife types, significant differences were also found (p < .0005). While significant differences in cut mark width were found, caution should be used in trying to classify indi...

The paper presents tribological behaviour of hybrid aluminium composite A356/10SiC/3Gr in dry-sliding conditions. Hybrid
composites were made with a modified compocasting procedure and tribological tests were conducted on a tribometer with a
block-on-disc contact geometry. An analysis of the effects of three sliding speeds ((0.25, 0.5 and 1) m/s) and two normal loads (10 N and 20 N) on the wear volume and wear rate was conducted for different sliding distances. The total sliding distance was
300 m. SEM and an EDS analysis of the wear surfaces of the tested material were also performed. The analysis of the wear
surfaces shows an intensive adhesive wear of hybrid composites. Also, the appearance of mechanically mixed layers (MMLs) was confirmed, i.e., an increase in the concentration of iron in the hybrid composite material.

Many efforts have been made to understand the effects of hydrogen on steels, resulting in an abundance of theoretical models and papers. However, a fully developed and practically applicable predictive physical model still does not exist industrially for predicting and preventing hydrogen damage. In practice, it is observed that different types of damages to industrial boiler components have been associated with the presence and localization of hydrogen in metals. In this paper, a damaged boiler tube made of grade 20 – St.20 (or 20G, equivalent to AISI 1020) was investigated. The experimental research was conducted in two distinctive phases: failure analysis of the boiler evaporator tube sample and subsequent postmortem analysis of the viable hydrogen embrittlement mechanisms (HE) in St.20 steel. Numerous tested samples were cut out from the boiler tubes of fossil fuel power plant, damaged due to high temperature hydrogen attack (HTHA) during service, as a result of the development of hydrogen-induced corrosion process. Samples were prepared for the chemical composition analysis, tube wall thickness measurement, tensile testing, hardness measurement, impact strength testing (on in-strumented Charpy machine), analysis of the chemical composition of corrosion products – deposit and the microstructural characterization by optical and scanning electron microscopy – SEM/EDX. The HTHA damage mechanism is a primary cause of boiler tube fracture. Based on the multi-scale special model, applied in subsequent postmortem investigations, the results indicate a simultaneous action of the hydrogen-enhanced decohesion (HEDE) and hydrogen-enhanced localized plasticity (HELP) mechanisms of HE, depending on the local concentration of hydrogen in investigated steel. The model is based on the correlation of mechanical properties to the SEM fractography analysis of fracture surfaces.

The composite effects of gum arabic (GA) (5, 10, 15, and 20%) and chitosan (CH) (1.0%) on the biochemical and physiological characteristics of banana fruits stored at 13 ± 1 °C and 80 ± 3% relative humidity (RH) for 28 days and afterward for 5 days at simulated marketing conditions (25 °C, 60% RH) were investigated. Significant (P ≤ 0.05) differences were observed for the entire GA plus CH treatments as compared to the control. However, the results showed that after 33 days of storage, the weight loss and soluble solids concentration of fruits treated with 10% GA plus 1.0% CH composite coating were 24 and 54% lower, whereas fruit firmness, total carbohydrates, and reducing sugars were 31, 59, and 40% higher than the control, respectively. Furthermore, the composite edible coating of 10% GA plus 1.0% CH delayed color development and reduced the rate of respiration and ethylene evolution during storage as compared to the control. Similarly, sensory evaluation results also proved the e...

"This research aims to contribute to the comprehensive study of Greek Orthodox ecclesiastical textiles and is focused on the identification of morphological and technological characteristics of the metal threads used for the decoration of these textiles. The results will help to explore possible stylistic and technological relationships among the various embroidery workshops operating during that time. Moreover, the data will allow examining exchanges of technological knowledge among the Greek craftsmen and among Greek, European and Ottoman ones during that period.
The project is based on the study of 117 objects decorated with metal threads obtained from several Greek and European Institutions. The Greek objects are mainly embroidered ecclesiastical textiles used by the Greek Orthodox Church across a large region and covering the 14th to 19th centuries. The objects from European institutions are primarily woven secular objects of European and Middle Eastern origins which are dated from the 13th century onwards.

"