277 results on '"Scanning electronic microscopy"'
Search Results
2. The comparative study of temperature rise, time consuming and cut quality among piezosurgery, conventional rotary instruments and Er: YAG laser in apicectomy
- Author
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Li-Yuan Qi, Rui Zhang, Juan Zhang, Jia-Sha Wang, Ji Wang, Ruo-Xi Liu, Yu Jin, and Jing Zhao
- Subjects
Apicectomy ,Endodontic surgery ,Er: YAG laser ,Scanning electronic microscopy ,Dentistry ,RK1-715 - Abstract
Abstract Objectives This study aimed to compare the temperature rise, time consuming and cut quality of apicectomy using three different methods. Materials and methods Twenty-four single-rooted teeth were collected and divided into four groups operating apicectomy with a NINJA tip of a piezoelectric device (G1), a diamond bur with 300,000 rpm (G2), and Er: YAG laser at 200 mJ/ 30 Hz (G3) as well as 250 mJ/ 30 Hz (G4). The temperature elevation and time were recorded and the cut quality was evaluated via stereomicroscope and scanning electronic microscopy (SEM). Results The temperature increases for G1 was significantly higher than for G2. However, there was no significant difference between G1 and G2 with laser groups respectively. The median time for apicectomy was: 100.14s for G1, 22.65s for G2, 33.58s for G3, and 21.80s for G4. G1 is the most time-consuming group and there was no statistically significance in the comparisons with G2, G3 and G4. Cut quality was assessed by crack occurrence, smear layer formation and dentinal tubules exposed. The percentage of cracked teeth in G1 and G2 was 33.33% and for laser groups the percentage was 16.67% each. SEM showed that no smear layer formed and almost all dentinal tubules were exposed on resected surfaces for G3&G4, surfaces from G2 were partly covered by smear layer, and surfaces from G1 were fully covered by smear layer and with no dentinal tubules exposed. Conclusions Er: YAG laser and conventional rotary instruments were safe and efficient for apicectomy and with a better cut quality when compared with piezoelectric equipment. Er: YAG laser could be a promising technique for apicectomy and further studies are necessary, especially larger sample in vivo investigations, to verify the feasibility of Er: YAG laser in endodontic surgery.
- Published
- 2024
- Full Text
- View/download PDF
3. Sea conch (Rapana venosa) peptide hydrolysate regulates NF‐κB pathway and restores intestinal immune homeostasis in DSS‐induced colitis mice.
- Author
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Ullah, Hidayat, Alioui, Yamina, Ali, Muhsin, Ali, Sharafat, Farooqui, Nabeel Ahmed, Siddiqui, Nimra Z., Alsholi, Duaa M., Ilyas, Muhammad, Rahman, Mujeeb U., Xin, Yi, and Wang, Liang
- Subjects
- *
INFLAMMATORY bowel diseases , *NF-kappa B , *PEPTIDES , *INTESTINAL diseases , *DRINKING (Physiology) - Abstract
Inflammatory bowel disease (IBD) is a chronic inflammatory condition of the gastrointestinal tract. Sea conch peptide hydrolysate (CPH) was produced by enzymatic digestion of fresh conch meat with trypsin enzyme. To analyze the molecular composition, functional groups, and structural morphology of the hydrolysate, we employed liquid chromatography–mass spectrometry (LC–MS), Fourier‐transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). Results confirmed that crude protein could be effectively digested by enzymes to generate peptides. In this study, we evaluated the bioactivities of CPH on dextran sulfate solution (DSS)‐induced colitis in mice. The findings demonstrated that CPH supplementation improved body weight, food and water intake, and colon length. The therapeutic efficacy and immunoregulatory effect of CPH were further determined. Our results exhibited that CPH treatment significantly ameliorated pathological symptoms by enhancing intestinal integrity, mucin production, and goblet cell count. Moreover, the immunoregulatory effect of CPH on mRNA expression levels of different pro‐ and anti‐inflammatory cytokines was determined. Results exhibited a decrease in the expression of pro‐inflammatory cytokines and an increase in anti‐inflammatory cytokines in the colon. Additionally, the CPH administration modulates the nuclear factor kappa B (NF‐κB) pathway, preventing DNA damage and cell death. Assays for apoptosis and DNA damage revealed that CPH reduced oxidative DNA damage and apoptosis. These findings highlight the immunomodulatory and treatment amelioration effect of CPH in reducing the severity of colitis. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
4. The comparative study of temperature rise, time consuming and cut quality among piezosurgery, conventional rotary instruments and Er: YAG laser in apicectomy.
- Author
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Qi, Li-Yuan, Zhang, Rui, Zhang, Juan, Wang, Jia-Sha, Wang, Ji, Liu, Ruo-Xi, Jin, Yu, and Zhao, Jing
- Subjects
APICOECTOMY ,DENTAL equipment ,ENDODONTICS ,LASERS ,STATISTICAL significance ,RESEARCH funding ,KRUSKAL-Wallis Test ,DESCRIPTIVE statistics ,LASER therapy ,SCANNING electron microscopy ,TEMPERATURE ,QUALITY assurance ,COMPARATIVE studies ,DATA analysis software ,PIEZOSURGERY ,TIME - Abstract
Objectives: This study aimed to compare the temperature rise, time consuming and cut quality of apicectomy using three different methods. Materials and methods: Twenty-four single-rooted teeth were collected and divided into four groups operating apicectomy with a NINJA tip of a piezoelectric device (G1), a diamond bur with 300,000 rpm (G2), and Er: YAG laser at 200 mJ/ 30 Hz (G3) as well as 250 mJ/ 30 Hz (G4). The temperature elevation and time were recorded and the cut quality was evaluated via stereomicroscope and scanning electronic microscopy (SEM). Results: The temperature increases for G1 was significantly higher than for G2. However, there was no significant difference between G1 and G2 with laser groups respectively. The median time for apicectomy was: 100.14s for G1, 22.65s for G2, 33.58s for G3, and 21.80s for G4. G1 is the most time-consuming group and there was no statistically significance in the comparisons with G2, G3 and G4. Cut quality was assessed by crack occurrence, smear layer formation and dentinal tubules exposed. The percentage of cracked teeth in G1 and G2 was 33.33% and for laser groups the percentage was 16.67% each. SEM showed that no smear layer formed and almost all dentinal tubules were exposed on resected surfaces for G3&G4, surfaces from G2 were partly covered by smear layer, and surfaces from G1 were fully covered by smear layer and with no dentinal tubules exposed. Conclusions: Er: YAG laser and conventional rotary instruments were safe and efficient for apicectomy and with a better cut quality when compared with piezoelectric equipment. Er: YAG laser could be a promising technique for apicectomy and further studies are necessary, especially larger sample in vivo investigations, to verify the feasibility of Er: YAG laser in endodontic surgery. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
5. The Influence of Hot Deformation on the Mechanical and Structural Properties of 42CrMo4 Steel.
- Author
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Pop, Mariana, Sas-Boca, Ioana-Monica, Frunză, Dan, Popa, Florin, and Neag, Adriana
- Subjects
DEFORMATIONS (Mechanics) ,STRAINS & stresses (Mechanics) ,STRAIN rate ,HIGH temperatures ,HARDNESS ,DUCTILE fractures - Abstract
The influence of elevated temperatures and strain rate on the mechanical and structural properties of steel 42CrMo4 were analysed experimentally in this paper. The experiments were based on uniaxial tension and compression tests at high temperatures between 700 °C and 1100 °C and strain rates in the range 0.0018–0.1 s
−1 . The influence of temperature and strain rate on yield stress, strain to fracture, hardness, structural changes, and fracture characteristics were analysed. The non-uniformity of deformations obtained at different values of the strain rate and temperature were also analysed. Analysis by scanning electron microscopy showed the ductile behaviour of the material. The degree of damage in the material caused by the presence of cavities increased with increasing deformation temperature. For all the presented deformation conditions, the formation of the fracture through the ductile fracture mechanism resulted from localized necking and the coalescence of microvoids. By increasing the deformation temperature and reducing the strain rate, the fracture behaviour of 42CrMo4 steel can be improved. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
6. Seeking for non‐friendly chemical elements in tabletop sugar and zero to low‐calorie sweetener sachets.
- Author
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Moussa, Hussein Abdul Karim, Espinola, Diego Osmar Galeano, Hernández, Sandy González, and Hönnicke, Marcelo G.
- Subjects
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SWEETENERS , *CHEMICAL elements , *SUGAR , *X-ray spectroscopy , *SUCROSE , *X-ray diffraction - Abstract
Different tabletop sugar and zero to low‐calorie sweetener samples (sachets) of different suppliers, taken randomly, at different cafeterias in Brazil, Argentina, and Paraguay have been selected, for spectroscopy and X‐ray diffraction analysis, to figure out if they can present non‐friendly components in their composition. Traces of sulfites and aluminosilicates make only 2 out of 16 tabletop sugar sweetener samples safe. On the other hand, traces of sucrose, lactose, sulfites, and aspartame, make only 1 out of 13 tabletop zero to low‐calorie sweetener samples, safe. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
7. A review on partial substitution of nanosilica in concrete
- Author
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Xiaohan Zhang, Ahmad Jawad, Jebur Yasir Mohammed, and Deifalla Ahmed Farouk
- Subjects
nanosilica ,compressive strength ,scanning electronic microscopy ,Technology ,Chemical technology ,TP1-1185 - Abstract
One of the most popular and widely used cementitious nanoparticle materials is nanosilica (NNS). Although several researchers discuss how NNS affects the characteristics of concrete, knowledge is dispersed, making it difficult for the reader to assess the precise advantages of NNS. Therefore, a detailed review is required for the substitution of NNS in concrete. The present reviews collect the recently updated information on NNS as concrete ingredients. First, a summary of the manufacturing, physical, and chemical characteristics of NNS is provided. Second, the characteristics of fresh concrete are examined, including its effect on setting time, flowability, air content, and fresh density. Third, strength properties such as compressive, tensile, and flexure capacity are discussed. Finally, microstructure analyses such as scanning electronic microscopy and X-ray diffraction are discussed. The results show that NNS enhanced the mechanical and durability of concrete due to the pozzolanic reaction and microfilling voids but decreased the slump flow. The optimum dose is important for maximum performance. The typical optimum dose of NNS varies from 1 to 3% by weight of cement. This article also suggests future research directions to improve the performance of NNS-based concrete.
- Published
- 2024
- Full Text
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8. Concrete Made with Partial Substitutions of Wheat Straw Ash: A Review
- Author
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Jawad Ahmad, Mohamed Moafak Arbili, Muwaffaq Alqurashi, Fadi Althoey, and Ahmed Farouk Deifalla
- Subjects
Eco-friendly concrete ,Wheat straw ash ,Mechanical strength ,Durability ,Scanning electronic microscopy ,Systems of building construction. Including fireproof construction, concrete construction ,TH1000-1725 - Abstract
Abstract Many scientists are now focusing their attention on the utilization of valuable industrial or agricultural wastes as the primary raw material for the construction sector. These wastes, on the other hand, are affordable and readily accessible, making them ideal for commercial use while also contributing to the reduction of environmental degradation. Wheat straw ash (WTSA) is a kind of agricultural waste that has the potential to be utilized in concrete. Although many researchers are focused on utilization of WTSA in concrete. However, an updated review is required which provides easy access for the reader to get an idea about the benefits of WTSA in concrete. Therefore, this study provides a comprehensive review of the utilization of WTSA as a concrete ingredient. Physical and chemical compositions of WTSA, flowability, mechanical strength (compressive, flexure, tensile strength, and elastic modulus), and durability properties (permeability, carbonation, ultrasonic pulse velocity, alkali-silica reaction and chloride attacks) are the main aspects of this review. Results indicate that the performance of concrete improved with partial substitutions of cement with WTSA but simultaneously decreased the flowability of concrete. The optimum dose is important as higher dose results in decreased mechanical strength. The typical optimum dose ranges from 10 to 20% by weight of the binder. The performance of concrete in terms of durability was also improved but less research is carried out on the durability performance of concrete with WTSA. Additionally, despite WTSA's improvement in mechanical strength, concrete still exhibits lower tensile strain, which leads to brittle failure. Therefore, it was recommended that further study should be done to increase its tensile strength.
- Published
- 2023
- Full Text
- View/download PDF
9. Improvement in the strength of concrete reinforced with agriculture fibers: Assessment on mechanical properties and microstructure analysis.
- Author
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Ahmad, Jawad, Mohammed Jebur, Yasir, Tayyab Naqash, Muhammad, Sheraz, Muhammad, Hakamy, Ahmed, and Farouk Deifalla, Ahmed
- Abstract
Concrete is weak in tension, causing brittle failure without warning. Fiber is one of the simplest techniques to increase tensile strain. Several kinds of fibers (synthetic) are available such as steel fiber, glass fiber, and carbon fiber. However, these fibers are expensive and cannot be easily accessible. Researchers use agricultural fiber in concrete instead of synthetic fibers to offset this deficiency. Although, several studies have shown that agricultural fiber may be utilized to increase concrete tensile strength. However, a details review is required which combines all relevant information and the reader can evaluate the benefits of agricultural fiber. Therefore, this review focus on a comprehensive and up-to-date overview of the impact of agricultural fiber on concrete slump flow, mechanical quality, and durability. Furthermore, scanning electronic microscopy, enhancement methods, and agricultural fiber-reinforced concrete (AFRC) applications are also reviewed. Five different types of agricultural fiber including coconut, jute, banana, rice straw, and hemp fibers were selected. According to the findings, agricultural fiber increased concrete's mechanical and durability qualities while comparably decreasing the slump. The optimum dose is essential as the higher dose adversely affects mechanical performance. The typical optimum amount varies from 1% to 2% by weight/volume of the binder. Among various types of agricultural fiber, coconut fiber is super performance. Less research is carried out on hemp, straw ash, and banana fibers than on coconut and jute fibers. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
10. Durability and microstructure analysis of concrete made with volcanic ash: A review (Part II)
- Author
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Ahmad Jawad, Althoey Fadi, Abuhussain Mohammed Awad, Deifalla Ahmed Farouk, Özkılıç Yasin Onuralp, and Rahmawati Cut
- Subjects
volcanic ash ,concrete ,durability ,heat of hydration ,scanning electronic microscopy ,Materials of engineering and construction. Mechanics of materials ,TA401-492 - Abstract
Concrete is the most frequently employed man-made material in modern building construction. Nevertheless, the serviceability of concrete structures has been significantly reduced owing to a variety of durability issues, especially when serving in a non-ideal environment and exposed to internal/external attacks such as chloride penetration, carbonation, sulfate, and so on. Several scholars have performed numerous studies on the strength and microstructure features of volcanic ash (VA) concrete and have discovered encouraging findings. However, since the information is spread, readers find it difficult to evaluate the benefits of VA-based concrete, limiting its applicability. As a result, a detailed study is required that offers the reader an easy approach and highlights all essential facts. The goal of this article (Part Ц) is to conduct a compressive review of the physical and chemical aspects of VA and its impact on concrete durability and microstructure properties. The findings demonstrate that VA considerably improves concrete durability owing to pozzolanic reaction and micro-filling voids in concrete materials. Cost–benefit analysis shows that 10% utilization of VA as cement decreased the overall cost by 30%. The assessment also notes a research gap that must be filled before VA may be utilized in practice.
- Published
- 2023
- Full Text
- View/download PDF
11. Improving the Properties of Saline Soil Using a Deep Soil Mixing Technique.
- Author
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Hammad, Mohamed A., Mohamedzein, Yahia, and Al-Aghbari, Mohamed
- Subjects
SOIL salinity ,ULTRASONIC testing ,SOILS ,SOIL structure ,SHEAR strength - Abstract
Saline soils belong to the category of problematic soils with high compressibility and weak shear strength when exposed to water. Water dissolves the salts in soils which are the primary cementing agents. Therefore, stabilization methods that provide sustainable cementing substances are employed in this study using deep soil mixing techniques to enhance the properties of saline soil. In this regard, a laboratory-scaled deep soil mixing procedure was developed to treat the soil in a way similar to the field methods. A binder, consisting of marble powder and cement, was employed to treat the soil. This study aimed to select the most efficient binder mix design in terms of optimum marble powder/cement ratio and optimum water/binder ratio. Unconfined compressive strength, durability, density measurements and ultrasonic velocity pulse tests were conducted on the treated soil. To determine the treatment efficacy, microstructure analysis of the treated samples was conducted. The 80C20MP and 70C30MP samples exhibit a dense soil structure with minimal voids, and their microstructure is denser than the other treated specimens. Additionally, the EDX analysis shows increased calcium percentages with up to 30% MP replacement, aligning well with the microstructure analysis and the UCS values. The results indicate that the economical and eco-friendly binder mix consisted of (70% to 80%) cement and (20% to 30%) marble powder with water/binder ratio in the range of 1.1 to 1.3. This mix contributed greatly to the improvement in soil strength and integrated columns. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
12. Concrete Made with Partial Substitutions of Wheat Straw Ash: A Review.
- Author
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Ahmad, Jawad, Arbili, Mohamed Moafak, Alqurashi, Muwaffaq, Althoey, Fadi, and Deifalla, Ahmed Farouk
- Subjects
ULTRASONIC testing ,CONCRETE durability ,CONCRETE ,AGRICULTURAL wastes ,INDUSTRIAL wastes - Abstract
Many scientists are now focusing their attention on the utilization of valuable industrial or agricultural wastes as the primary raw material for the construction sector. These wastes, on the other hand, are affordable and readily accessible, making them ideal for commercial use while also contributing to the reduction of environmental degradation. Wheat straw ash (WTSA) is a kind of agricultural waste that has the potential to be utilized in concrete. Although many researchers are focused on utilization of WTSA in concrete. However, an updated review is required which provides easy access for the reader to get an idea about the benefits of WTSA in concrete. Therefore, this study provides a comprehensive review of the utilization of WTSA as a concrete ingredient. Physical and chemical compositions of WTSA, flowability, mechanical strength (compressive, flexure, tensile strength, and elastic modulus), and durability properties (permeability, carbonation, ultrasonic pulse velocity, alkali-silica reaction and chloride attacks) are the main aspects of this review. Results indicate that the performance of concrete improved with partial substitutions of cement with WTSA but simultaneously decreased the flowability of concrete. The optimum dose is important as higher dose results in decreased mechanical strength. The typical optimum dose ranges from 10 to 20% by weight of the binder. The performance of concrete in terms of durability was also improved but less research is carried out on the durability performance of concrete with WTSA. Additionally, despite WTSA's improvement in mechanical strength, concrete still exhibits lower tensile strain, which leads to brittle failure. Therefore, it was recommended that further study should be done to increase its tensile strength. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
13. The Influence of Hot Deformation on the Mechanical and Structural Properties of 42CrMo4 Steel
- Author
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Mariana Pop, Ioana-Monica Sas-Boca, Dan Frunză, Florin Popa, and Adriana Neag
- Subjects
steel ,tensile test ,compression test ,elevated temperatures ,scanning electronic microscopy ,Mining engineering. Metallurgy ,TN1-997 - Abstract
The influence of elevated temperatures and strain rate on the mechanical and structural properties of steel 42CrMo4 were analysed experimentally in this paper. The experiments were based on uniaxial tension and compression tests at high temperatures between 700 °C and 1100 °C and strain rates in the range 0.0018–0.1 s−1. The influence of temperature and strain rate on yield stress, strain to fracture, hardness, structural changes, and fracture characteristics were analysed. The non-uniformity of deformations obtained at different values of the strain rate and temperature were also analysed. Analysis by scanning electron microscopy showed the ductile behaviour of the material. The degree of damage in the material caused by the presence of cavities increased with increasing deformation temperature. For all the presented deformation conditions, the formation of the fracture through the ductile fracture mechanism resulted from localized necking and the coalescence of microvoids. By increasing the deformation temperature and reducing the strain rate, the fracture behaviour of 42CrMo4 steel can be improved.
- Published
- 2024
- Full Text
- View/download PDF
14. Characterization Studies on New Natural Cellulosic Fiber Extracted from the Bark of Erythrina variegata
- Author
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R. Gopinath, P. Billigraham, and T.P. Sathishkumar
- Subjects
erythrina variegata ,mechanical properties ,thermal properties ,chemical constituent ,cellulose fiber ,scanning electronic microscopy ,Science ,Textile bleaching, dyeing, printing, etc. ,TP890-933 - Abstract
This research was aimed at investigating the physicochemical, thermal, and mechanical properties of newly identified cellulosic fiber extracted from the bark of Erythrina variegata (EV) tree. The chemical analysis of EVFs revealed the existence of high cellulose (50.64 wt.%) and lignin content (17.44 wt.%) which in turn makes the fiber rigid and strong. Crystallinity index and crystallite size of EVFs determined through X-ray diffraction analysis were found to be 51.80% and 3.00 nm. High onset temperature for hemicellulose degradation (227.99°C) and high activation energy (74.05 kJ/mol) confirms the thermal stability of EVFs. The tensile strength and young’s modulus of EVF were found to be 503.2315 ± 202.23 MPa and 7.62 ± 2.91 GPa. The FESEM micrographs of EVFs revealed the existence of a rough fiber surface, which facilitate better interfacial adhesion with the polymer matrix.
- Published
- 2022
- Full Text
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15. Natural history and morphology of immature stages of Tolype medialis (Jones, 1912) (Lepidoptera: Lasiocampidae: Macromphaliinae)
- Author
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Piovesan, Mônica, dos Santos, Fábio Luis, Orlandin, Elton, Specht, Alexandre, Mielke, Olaf Hermann Hendrik, and Casagrande, Mirna Martins
- Published
- 2023
- Full Text
- View/download PDF
16. Characterization Studies on New Natural Cellulosic Fiber Extracted from the Bark of Erythrina variegata.
- Author
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Gopinath, R., Billigraham, P., and Sathishkumar, T.P.
- Subjects
NATURAL fibers ,CELLULOSE fibers ,PAPAYA ,SISAL (Fiber) ,MOISTURE content of plants - Abstract
Keywords: Erythrina variegata; mechanical properties; thermal properties; chemical constituent; cellulose fiber; scanning electronic microscopy; ; ; ; ; ; EN Erythrina variegata mechanical properties thermal properties chemical constituent cellulose fiber scanning electronic microscopy ZH 8246 8265 20 11/21/22 20221220 NES 221220 Introduction Rapid changes in the climate and environment has necessitated the use of eco-friendly materials in all applications of mankind. Higher lignin content makes EVF rigid and protects the fiber from biological attack by holding water in the fiber (Madhu et al. [32]).The hemicelluloses content in EVFs (37.38%) is comparatively higher than most of the plant fibers. The chemical analysis revealed existence of cellulose, hemicellulose, and lignin in composition such as 50.64 wt.%, 37.38 wt.%, and 17.44 wt.%. The presence of both cellulose and lignin in larger quantity makes the fiber stronger and stable compared to other bast fibers. Some of the recently explored bark fibers which were used for making polymer composites include I Cissus Populnea i (Azeez et al. [4]), I Cordia-Dichotoma i (Madhusudhan et al. [33]), I Sterculia urens i (Hemachandra et al. [14]), I Grewia optiva i (Kumar et al. [27]), I Abutilon Indicum i (Mohana, Sreeramulu, and Venkateshwar Reddy [40]), I Cyperus pangorei i (Rajini et al. [53]), Azadirachtaindica (Manimaran et al. [38]), Mikaniamicrantha and Chromolaenaodorata (Vijayan and Joy [72]), Salago (Pouriman et al. [50]), Raffia Vinifera (Rodrigue et al. [55]), Urena lobata (Njoku et al. [44]), Pigeon Pea (Kulandaivel, Muralikannan, and KalyanaSundaram [25]), Bauhinia Vahlii (Patel et al. [48]), I Calotropis procera i (Yoganandam et al. [74]) and I Carica Papaya i (Saravana Kumar et al. [58]), I Erythina variegata i is one such novel species from the bark of which good quality fibers can be obtained. [Extracted from the article]
- Published
- 2022
- Full Text
- View/download PDF
17. Micropropagation using direct and indirect organogenesis in Artemisia maritima L.: scanning electron microscopy of somatic embryos and genome size analysis by flow cytometry.
- Author
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Nabi, Neelofer, Saffeullah, Peer, and Singh, Seema
- Subjects
- *
SOMATIC embryogenesis , *FLOW cytometry , *GENOME size , *SCANNING electron microscopy , *REGENERATION (Botany) , *MORPHOGENESIS - Abstract
In this study, an efficient, reproducible, and genetically stable regeneration protocol has been developed in Artemisia maritima L. The experiments were conducted for callus induction, plant regeneration, and somatic embryogenesis using stem and leaf of A. maritima as explants. The optimal callus induction (81.3%) was observed on 2.5 mg L−1 2,4-dichlorophenoxyacetic acid (2,4-D) and 1.5 mg L−1 6-benzylaminopurine (BAP). The shoot regeneration was observed on different concentrations of BAP, α-naphthaleneacetic acid (NAA), and thidiazuron (TDZ), using nodal segments and microshoot tips as explants. The microshoot tips were more responsive compared to nodal segments with the highest induction frequency (90.33%) obtained on 1.5 mg L−1 BAP. Maximum root induction frequency (74.36%) was obtained on 1.5 mg L−1 NAA. The somatic embryogenesis was induced on Murashige and Skoog (MS) medium amended with TDZ and indole-3-butyric acid (IBA) with maximum embryogenic induction frequency on 1.0 mg L−1 TDZ and 2.5 mg L−1 IBA. The somatic embryos developed into globular, heart-shaped, and bipolar plantlet stages on BAP and NAA as revealed through scanning electronic microscopy (SEM) and histological studies. The fully developed plants were acclimatized (75% survival rate) and transferred to natural photoperiod conditions. The DNA content and genetic stability of direct regenerated and somatic embryo–derived plants were analyzed by flow cytometry. The 2C DNA content of in vivo plants, direct regenerated, and somatic embryo–derived plants was 14.89, 14.61, and 14.37 pg, respectively. The genetic stability was maintained in in vitro cultures in comparison to field-grown plants of A. maritima. This study for the first time tried to formulate regeneration protocol via direct and indirect organogenesis and somatic embryogenesis for A. maritima. This paper was also the first report for comparing the 2C DNA content of A. maritima grown in vivo to in vitro cultured plants. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
18. Carica papaya Seeds and Its Active Constituent Benzyl Isothiocyanate against Corrosion of Aluminum.
- Author
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Vinutha, M. R., Rao, Padmalatha, Rao, Suma, and Bhat, Pushpanjali
- Abstract
Benzyl isothiocyanate was isolated from an aqueous extract of Carica papaya seeds. Phytochemical screening and isolation of the active components were carried out via high performanvice liquid chromatography and liquid chromatography–mass spectrometry. Both the Carica papaya seed aqueous extract and its most active component were investigated for the ability to inhibit 6061 aluminum alloy corrosion in an acidic medium (pH 3). Electrochemical techniques, scanning electronic microscopy and energy dispersive X-ray spectroscopy were employed to study anti-corrosion activities. The study was carried out by varying the concentrations of the inhibitor to find out its optimum efficiency. Kinetic parameters were evaluated and discussed in detail. Results were fitted into an appropriate adsorption isotherm. By using the data obtained from the adsorption isotherm and the Gibbs–Helmholtz equation, thermodynamic parameters for the adsorption were computed. A suitable mechanism was proposed for the corrosion inhibition process. Surface morphology studies confirmed the adsorption of the inhibitor. The density functional theory in the study of benzyl isothiocyanate also supported the obtained experimental results. To sum up, the active component of Carica papaya seeds is an efficient corrosion inhibitor, being cost effective and not harmful to the environment. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
19. Ultrastructure Traits and Genetic Variability of Red Palm Weevil Rhynchophorus ferrugineus (Olivier) Adults from Different Geographical Locations in Egypt.
- Author
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El-Zoghby, Islam R. M., Awad, Nabil S., Alkhaibari, Abeer Mousa, and Abdel-Hameid, Naglaa F.
- Subjects
- *
GENETIC variation , *CURCULIONIDAE , *ADULTS , *PALMS , *RAPD technique , *BIODIVERSITY - Abstract
The Red Palm Weevil (RPW) is one of the most damaging pests to palm cultivation; this invasive weevil poses a threat to the palm industry. The characterization and identification of this pest in order to determine its biological diversity is the first step in controlling it, which will help in developing effective control programs. The purpose of this study is to investigate the biodiversity of and characterize RPW from five different Egyptian geographical locations at morphological and genetic levels using morphometric analysis, scanning electronic microscopy and two different genetic markers. Our results revealed no significant differences between length and width of the adult body among RPW adults from different geographical locations. Different typologies of prothoracic spots were observed, indicating a degree of diversity in the RPW populations. The magnitude of the different body parts was measured among both males and females. Significant differences were exhibited between length of the antennal seta, as well as forelegs, the lengths and widths of the pronotum, and the rostrum length between both sexes. Both RAPD and ISSR used DNA markers, generating reproducible and distinct banding patterns. The polymorphic banding patterns that have resulted from all studied populations confirmed that these markers demonstrate genetic variability amongst the studied Egyptian populations of Rhynchophorus ferrugineus. The recorded differences may be due to the presence of different red palm weevil genotypes. The obtained results might have potential applications in developing a new tracking and control strategy for this invasive pest. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
20. Vibration influence on a siler as an innovative method of sealing root cannels
- Subjects
пломбирование ,корневые каналы ,сканирующая электронная микроскопия ,вибрационное воздействие ,sealing root canal ,scanning electronic microscopy ,vibration influence ,Dentistry ,RK1-715 - Abstract
Results of the scanning electronic microscopy of of shlif of the extracted teeth, after a preliminary obturation of root cannels by different methods of sealing are presented in article. The technique of distribution of the sealing material entered into the root canal by vibration influence (Sonic Air) with the subsequent application of lateral condensation by gutta-percha pins is for the first time offered. The siler on which sound impact was entered into the root canal, and then the method of lateral condensation was applid by guttta-percha pins. Four methods of an obturation of the root canal were compared: lateral condensation, an obturation of the root canal warmed gutta-percha on the carrier, a method of a continuous wave, vibration distribution of sealing material with the subsequent application of lateral condensation by gutta-percha pins. As a result of researches it was revealed that the smallest extent of regional microdribble the method of lateral condensation added with vibration influence on a siler, end also thermoplastic gutta-percha with application of a method of continuous wave and Gutta Fusion that is comfirmed by data of electronic microscopy possesses.
- Published
- 2020
21. A comparative evaluation of techniques of the removal of calcium hydroxide from root canals
- Subjects
гидроксид кальция на основе силиконового масла ,раствор для высушивания и обезжиривания корневых каналов ,сканирующая электронная микроскопия ,удаление препаратов гидроксида кальция ,metapex ,calcium hydroxide on the basis of silicone oil ,solution for drying and degreasing of root canals ,scanning electronic microscopy ,removal of calcium hydroxide preparations ,Dentistry ,RK1-715 - Abstract
Preparations of calcium hydroxide have widely started to be used in endodontics since 1920. In domestic literature there are not enough data on quality of processing of root canals after temporary sealing by such preparations. In our research we suggest to use for removal of preparations of calcium hydroxide solution for drying and degreasing of root canals. The quality and quantitative evaluation of processing of root canals after temporary sealing by calcium hydroxide on the basis of the data radiological research and data of scanning electronic microscopy were conducted. The results obtained allow to recommend the use of a solution for drying and degreasing of the root canal to remove the drug Hydrol Metapex of the root canal.
- Published
- 2020
22. Laboratory evaluation of influence of quality treating of root canals from calcium hydroxide on adhesion of root sealers
- Subjects
гидроксид кальция ,рентгенодиагностика ,сканирующая электронная микроскопия ,адгезионная прочность ,ультразвуковая пассивная ирригация ,calcium hydroxide ,radiological research ,scanning electronic microscopy ,adhesive durability ,passive ultrasonic irrigation ,Dentistry ,RK1-715 - Abstract
Results of work on definition of solvent of the Metapex, evaluation of quality treating of root canals are presented in this article after temporary sealing by calcium hydroxide. Are described results of carrying out radiological and scanning electronic microscopy researches. Also presented results on determination of adhesive durability of two types of root sealers. The assessment of influence of quality of treating root canals from preparations of calcium hydroxide on adhesion of sealers is given. The combination of medical ultrasonic passive irrigation with irrigation works best when you remove from the surface of root canal preparations of calcium hydroxide.
- Published
- 2020
23. Integrative Taxonomy Reveals Molicola uncinatus and Gymnorhynchus gigas (Cestoda: Trypanorhyncha) Coinfection in the Atlantic Pomfret Brama brama From the Mediterranean Sea, With Notes on the Phylogenetic Position of G. gigas Within the Family Gymnorhynchidae
- Author
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Mario Santoro, Marialetizia Palomba, Renato Aco Alburqueque, and Simonetta Mattiucci
- Subjects
larval trypanorhynchs ,phylogenetic analysis ,scanning electronic microscopy ,18S rDNA ,28S rDNA ,fish parasites ,Veterinary medicine ,SF600-1100 - Abstract
The cestode family Gymnorhynchidae Dollfus, 1935 (Trypanorhyncha) comprises three genera and six valid species that are typically intestinal parasites of large pelagic sharks. Members of Gymnorhynchidae show a wide geographic distribution and represent a global sanitary concern because as larvae they infect the edible flesh of several commercially important fishes with some species having allergenic potential. Larval Gymnorhynchidae collected from the muscles of the Atlantic pomfret Brama brama from various localities in the Mediterranean Sea were identified and characterized by combining traditional morphology, scanning electronic microscopy, and molecular analyses using newly generated nuclear 18S and 28S rRNA sequences. Overall, 98 larvae were collected from 20 (100%) Atlantic pomfrets (intensity of infection: 4.9; range: 1–12). High-quality sequences were obtained for 54 larvae. Of these, 11 and 43 larvae were identified as Molicola uncinatus and Gymnorhynchus gigas, respectively. The phylogenetic analysis showed the existence of three main clades within Gymnorhynchidae. The first included species of G. gigas and M. uncinatus from the Mediterranean and Atlantic; the second and third major clades included an unidentified species of Molicola from the Indian Ocean and specimens of Gymnorhynchus isuri from the Mediterranean and Atlantic, respectively. Finally, Chimaerarhynchus rougetae was the basal and most diverging taxon. The phylogenetic analysis suggested that G. gigas is more closely related to the members of Molicola. We demonstrated the coinfection of M. uncinatus and G. gigas from all localities studied and extended the intermediate hosts and geographical range of M. uncinatus by including the Atlantic pomfret and the Tyrrhenian and Ionian Seas, respectively. The present results supported the previous proposal that G. gigas and Molicola species should be included in the same genus. Our study demonstrated the usefulness of the integrative taxonomy for the unequivocal recognition of larval trypanorhynch species, resolving the current difficulties in the taxonomy, and elucidating the poorly known ecological and biological aspects of members of Gymnorhynchidae.
- Published
- 2022
- Full Text
- View/download PDF
24. Subulura eliseae sp. n. (Ascaridida: Subuluroidea), a parasite of Marmosa spp. from Amazon rainforest, Brazil.
- Author
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Andrade Silva, B.E. d., Vilela, R. do Val, Freitas, L. da Costa, Pacheco, R.d. Campos, de Mendonça, R.F.B., Rossi, R.V., and Maldonado, A.
- Subjects
- *
CYTOCHROME oxidase , *NUMBERS of species , *RAIN forests , *LARGE intestine , *SCANNING electron microscopy , *PARASITES - Abstract
The parasite biodiversity of mouse opossums in Brazil remains incompletely explored. We describe a new species of Subulura (Ascaridida: Subuluroidea) from the large intestine of the white-bellied woolly mouse opossum, Marmosa constantiae, based on the results of light and scanning electron microscopy (SEM). We also partially sequenced the mitochondrial cytochrome c oxidase I (MT-CO1) gene of the new species, using molecular phylogenetic analyses to determine its relationships within the Subuluroidea superfamily. As molecular data on subuluroid species are extremely limited, few inferences could be drawn from our phylogenies. Our SEM observations showed the detailed morphology of the cephalic extremity, precloacal pseudo-sucker, caudal papillae, phasmids and vulva. Subulura eliseae sp. n. differs from the other four Subulura parasites species of marsupials by the number of caudal papillae and the structure dimensions, and size of the spicule. Moreover, S. eliseae sp. n. has ten pairs of caudal papillae, which is unique compared to other species. We present morphometric and molecular data on this new species, contributing to future studies on subuluroids. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
25. Comparative morphology of eggs of Rhodnius domesticus Neiva & Pinto, Rhodnius neglectus Lent and Rhodnius prolixus Stål (Hemiptera: Reduviidae: Triatominae).
- Author
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Seabra, Allan Pitta, Oliveira-Correia, João Paulo Sales, and Galvão, Cleber
- Subjects
- *
RHODNIUS prolixus , *COMPARATIVE anatomy , *CONENOSES , *ASSASSIN bugs , *HEMIPTERA , *INSECT morphology - Abstract
Rhodnius species are potential vectors of the etiological agent of Chagas disease (CD), the protozoan Trypanosoma cruzi. CD impacts around seven million people in Latin America, resulting in approximately fourteen thousand deaths per year. Several species of Rhodnius are notable not only for their epidemiological relevance, but also for the challenging distinction between their species. Rhodnius has twenty species, each with its specific epidemiological importance. Rhodnius neglectus and Rhodnius prolixus are found with colonies in domiciliary environments. The observation of eggs in human dwellings signals the colonization process of these insects, increasing the risk of contamination of the population, since correct identification of eggs is necessary to help more effective vector control programs. Here we highlight diagnostic characters of eggs for these three species. [Display omitted] • Cells have different shapes, varying in different regions. • Cells show differences between species and between regions of the same species. • The three species showed significant differences in terms of limiting lines. • The funnels present variations in the aspect of their depth; different regions. • Differences were observed in the operculum of the three species. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
26. Effect of the CuAl2O4 and CuAlO2 Phases in Catalytic Wet Air Oxidation of ETBE and TAME using CuO/γ‐Al2O3 catalysts
- Author
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Cecilia Sánchez‐Trinidad, Gloria del Angel, Gilberto Torres‐Torres, Adrián Cervantes‐Uribe, A. Abiu Silahua Pavón, Zenaida Guerra‐Que, Juan Carlos Arévalo‐Pérez, and Fancisco J. Tzompantzi‐Morales
- Subjects
heterogeneous catalysis ,Cu/Al2O3 catalysts ,scanning electronic microscopy ,X-ray diffraction studies ,wet air oxidation reaction ,Chemistry ,QD1-999 - Abstract
Abstract This paper studies Cu/Al2O3 catalysts, synthesized in two ways: copper deposit in the synthesis of alumina (sol gel) and incipient impregnation stabilized at 400 °C. The materials were characterized by X‐ray diffraction studies, nitrogen physisorption, temperature programmed reduction of H2, dehydration of isopropanol, scanning electronic microscopy, transmission electronic microscopy, which were evaluated in the liquid phase oxidation reaction of ethyl tert‐butyl ether and tert‐amyl methyl ether. The formation of CuAl2O4 and CuAlO2 in the samples synthesized by sol gel, led to a modification of the texture, thus resulting in an expansion of the specific area of the materials. CuAl2O4 and CuAlO2 have been identified by DRX from a content of 10 % Copper, the first showed the highest intensity with this technique. In the same way, these species favor the presence of Lewis acid sites; this is reflected in the materials with (Di‐isopropyl Ether) DIPE of 96.7 % and 91.1 % for the samples SAlCu5 and SAlCu15 respectively. The catalytic activity of the materials prepared by sol gel is in the function of the number of surface acid sites, the smaller particle size of the Cu and the surface of the contact, in the case of the ETBE meanwhile for TAME the activity was based mainly on the strength of the present acid sites. With impregnated materials, the activity is attributed to the smaller particle size of the Cu and the greater strength of the surface acid sites in the solid. The formation of spinel species inhibits the leaching phenomenon in the reaction milieu.
- Published
- 2019
- Full Text
- View/download PDF
27. Cell wall break down of pitanga fruit (Eugenia uniflora L.) is associated with pectic solubilisation and softening.
- Author
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Oliveira, Ana Lázara Matos de, Vilela, Daiana Ribeiro, Zitha, Elídio Zaidine Maurício, de Barros, Hanna Elisia Araújo, Lago, Rafael Carvalho do, Carvalho, Elisangela Elena Nunes, and Vilas Boas, Eduardo Valério de Barros
- Subjects
- *
FRUIT ripening , *EUGENIA , *PRODUCE markets , *FRUIT , *PECTINS , *POLYGALACTURONASE - Abstract
Summary: Pitanga fruit stands out for its exotic flavour and antioxidant properties. The objective of this work was to evaluate changes in the physical, chemical and biochemical variables of red pitanga variety, in four stages of development (green, yellow, orange and red) and associate them to the cell wall break down. Analysis of pH, titratable acidity, soluble solids, firmness, soluble pectin, pectinamethylesterase (PME), polygalacturonase (PG), cell wall swelling and microstructure were performed. pH and levels of soluble solids and soluble pectin increased, in addition to the cell wall swelling and reduction of firmness, throughout the development of pitanga. From the SEM, it was possible to observe the degradation of the fruit cell wall during ripening, suggesting mainly the degradation of pectic polysaccharides, verified by the solubilisation of these substances. PG and PME enzymes were not active, which suggests that other enzymes may be associated with the cell wall break down. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
28. Evaluation of Surface Characteristics and Weight Variation of Different Composite Resins after Simulated Toothbrushing.
- Author
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Medeiros De Almeida, Jéssika Raíssa, Mangino Messias, Aion, Ferreira Gadelha, Diana, Fernandes Rabelo Caldas, Sergei Godeiro, and Galvão Rabelo Caldas, Marília Regalado
- Subjects
DENTAL resins ,DENTAL fillings ,SCANNING electron microscopy ,DENTAL materials ,SURFACE roughness - Abstract
Objective: To evaluate the surface characteristics of restorations performed after simulated toothbrushing and to compare the results between the composites. Materials and Methods: In total, 80 samples were made (7 mm × 4 mm) from the composites: Bulk Fill One, Bulk Fill Flow, Z350 XT, and Z350 XT flow (3M/ESPE, St. Paul, MN, USA). Half of the specimens was submitted to 60,000 cycles of simulated toothbrushing, while the other half was the control group (n = 10). The surface was evaluated through Scanning electronic microscopy (SEM), surface roughness (Ra), and weight loss, before and after the simulated toothbrushing. To evaluate the statistical analysis, a two-factors variance test and the Tukey's posttest were performed. Results: In the analysis performed by SEM, it was observed the presence of both small and medium protruding particles in all groups after simulated toothbrushing, with the exception of the group which used Z350 flow composite. All materials presented increasing on Ra after simulated toothbrushing. Regarding weight variation, there was not any significant statistical difference in all materials. Conclusions: The abrasive process occasioned by toothbrushing leads to changes on the particles' disposition, which causes changes on the surface and increase on the Ra. On the other hand, there was not any difference regarding to weight variation. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
29. Influence of the aerosol flow and exposure time on the structural changes in the filtering half masks material
- Author
-
Ivanković Negovan, Rajić Dušan, Karkalić Radovan, Janković Dušan, Radovanović Željko, Stupar Stevan, and Janković Darko
- Subjects
filtration dynamics ,structure porosity ,fiber properties ,scanning electronic microscopy ,Chemistry ,QD1-999 - Abstract
The flow of air and aerosol particles through the filtering half masks material depends on the structure porosity. It is very difficult to determine the behaviour of the filtering material during the process of extraction and retention of aerosols. The samples of five filtering half mask models were used in this investigation. Dynamics of the aerosol filtration through the filtering materials was tested using a method for testing the leakage of aerosol particles through the filtering material and a method for testing the inhalation resistance of filtering material, both specified in the SRPS EN 149:2013. Recording of the structural changes in the samples of the tested materials was carried out by the technique of scanning electron microscopy. The experiments showed a deviation of the results in relation to the theory of filtration the finely dispersed submicron sized particles. It was concluded that the aerosol leakage through the filtering half masks and their resistance to aerosol flow change depend on the aerosol flow rates and the on filtration process duration, as a direct consequence of the newly-made changes in the structure of the filtering material and due to reversibility effect between the filtration process and the changes in the filtering material. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR34034 and Grant no. III45019]
- Published
- 2018
- Full Text
- View/download PDF
30. Tools for the Study of Nanostructures
- Author
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Escamilla-García, M., Alvarado-González, J.S., Calderón-Domínguez, Georgina, Chanona-Pérez, J.J., Méndez-Méndez, Juan V., Perea-Flores, María de Jesús, Farrera-Rebollo, R.R., Barbosa-Cánovas, Gustavo V., Series editor, Hernández-Sánchez, Humberto, editor, and Gutiérrez-López, Gustavo Fidel, editor
- Published
- 2015
- Full Text
- View/download PDF
31. Effect of the CuAl2O4 and CuAlO2 Phases in Catalytic Wet Air Oxidation of ETBE and TAME using CuO/γ‐Al2O3 catalysts.
- Author
-
Sánchez‐Trinidad, Cecilia, del Angel, Gloria, Torres‐Torres, Gilberto, Cervantes‐Uribe, Adrián, Pavón, A. Abiu Silahua, Guerra‐Que, Zenaida, Arévalo‐Pérez, Juan Carlos, and Tzompantzi‐Morales, Fancisco J.
- Subjects
BUTYL methyl ether ,DEHYDRATION reactions ,ETHER (Anesthetic) ,CATALYSTS ,CATALYTIC activity ,METHYL ether ,PHYSISORPTION ,MIXED oxide catalysts - Abstract
This paper studies Cu/Al2O3 catalysts, synthesized in two ways: copper deposit in the synthesis of alumina (sol gel) and incipient impregnation stabilized at 400 °C. The materials were characterized by X‐ray diffraction studies, nitrogen physisorption, temperature programmed reduction of H2, dehydration of isopropanol, scanning electronic microscopy, transmission electronic microscopy, which were evaluated in the liquid phase oxidation reaction of ethyl tert‐butyl ether and tert‐amyl methyl ether. The formation of CuAl2O4 and CuAlO2 in the samples synthesized by sol gel, led to a modification of the texture, thus resulting in an expansion of the specific area of the materials. CuAl2O4 and CuAlO2 have been identified by DRX from a content of 10 % Copper, the first showed the highest intensity with this technique. In the same way, these species favor the presence of Lewis acid sites; this is reflected in the materials with (Di‐isopropyl Ether) DIPE of 96.7 % and 91.1 % for the samples SAlCu5 and SAlCu15 respectively. The catalytic activity of the materials prepared by sol gel is in the function of the number of surface acid sites, the smaller particle size of the Cu and the surface of the contact, in the case of the ETBE meanwhile for TAME the activity was based mainly on the strength of the present acid sites. With impregnated materials, the activity is attributed to the smaller particle size of the Cu and the greater strength of the surface acid sites in the solid. The formation of spinel species inhibits the leaching phenomenon in the reaction milieu. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
32. Effect of Rot-Retardant Treatment on Properties of Jute Fibers
- Author
-
Sweety Shahinur, Mahbub Hasan, Qumrul Ahsan, and Shamina Jafrin
- Subjects
fourier transform infrared spectroscopy ,jute fiber ,rot retardant ,scanning electronic microscopy ,tensile properties ,x-ray diffraction ,Science ,Textile bleaching, dyeing, printing, etc. ,TP890-933 - Abstract
Jute natural fiber is gradually replacing traditional glass fibers as reinforcement in composites due to their higher specific modulus and lower specific gravity. For reducing rotting properties of jute fiber, rot-retardant treatment was conducted on different portions of the fiber. The rot-retardant jute fibers were characterized by tensile test, Fourier transform infra-red spectroscopy, scanning electron microscopy, X-ray diffraction analysis, and thermal and water absorption tests. The tensile properties improved in the middle portion as compared to the top and bottom portions and deteriorated after rot-retardant treatment. The diameter gradually increased from top to middle and then to bottom portion after treatment. The crystalinity index was found higher for bottom portion. Thermal properties of jute fiber also improved as compared to the control jute fiber. The rot-retardant--treated jute fiber may find satisfactory and desirable application in our house hold accessories.
- Published
- 2017
- Full Text
- View/download PDF
33. Hirtellina lobelii DC. essential oil, its constituents, its combination with antimicrobial drugs and its mode of action.
- Author
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Khoury, Madona, El Beyrouthy, Marc, Ouaini, Naïm, Eparvier, Véronique, and Stien, Didier
- Subjects
- *
ANTI-infective agents , *COMBINATION drug therapy , *CHROMATOGRAPHIC analysis , *PREVENTION of communicable diseases , *DRUG resistance in microorganisms , *DRUG synergism , *ESSENTIAL oils , *MASS spectrometry , *MEDICINAL plants , *MOLECULAR structure , *NUCLEAR magnetic resonance spectroscopy - Abstract
Abstract With the goal of unravelling antimicrobial agents and mixtures inspired by plant defences, we investigated the antibacterial and antifungal efficacy of Hirtellina lobelii DC. essential oil (EO), both alone and in combination with antimicrobial drugs. Hirtellina lobelii DC. EO was analysed by GC, GC–MS and partial fractionation/NMR. It was essentially composed of oxygenated sesquiterpenes (75.2%), with α-bisabolol (34.5%), fokienol (12.0%) and T-muurolol (6.8%) serving as the main components. Microbial susceptibility was determined by the broth microdilution method and was expressed as minimum inhibitory concentration (MIC) and minimum bactericidal or fungicidal concentration (MBC or MFC). This EO was found to possess remarkable bactericidal (MBC/MIC = 2) and fungicidal (MFC/MIC = 1–4) potential, particularly against the Gram (+) bacteria Staphylococcus aureus , including its methicillin-resistant forms , the yeast Cryptococcus neoformans and dermatophytes from the genus Trichophyton (MICs 8–128 μg/ml). The examination of the combined effects of the EO with antimicrobial drugs revealed synergisms of the EO with vancomycin against S. aureus and of the EO with fluconazole and griseofulvin against dermatophytic fungi (FICI 0.2–0.5). The effect of H. lobelii EO on the morphologies of fungal hyphae and bacteria, as determined by scanning electronic microscopy (SEM), showed fungal hyphae swelling and bulging. These results suggest that H. lobelii EO and its major constituent, α-bisabolol, have remarkable antimicrobial potential. Combination therapies of this EO with antifungal drugs could offer a promising alternative for treatment of human mycoses caused by filamentous dermatophytic fungi. Graphical abstract Unlabelled Image [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
34. Instant controlled pressure-drop as texturing pretreatment for intensifying both final drying stage and extraction of phenolic compounds to valorize orange industry by-products (Citrus sinensis L.).
- Author
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Louati, Ines, Bahloul, Neila, Besombesb, Colette, Allaf, Karim, and Kechaou, Nabil
- Subjects
- *
ORANGES , *PHENOLS , *ORANGE peel , *WASTE products , *SOLVENT extraction , *SCANNING electron microscopy - Abstract
This work deals with the economic valorization of orange industry by-products by intensification of both drying kinetics and extraction of phenolic compounds of orange peel using the instant controlled pressure-drop DIC technology. DIC treatment is usually performed on partially dried samples. It starts with a heating/pressurizing stage for a short thermal treatment time to end by an instant depressurization towards a vacuum. In the present case, orange-peel was DIC-textured to be airflow oven dried at 40 °C, 2 m s-1, and 265 Pa of vapor as relative humidity, to reach a final moisture of about 0.05 g H20/g db. By assuming this operation as shrinkage-free with conditions of Negligible External Resistance (NER), the Coupled Washing/Diffusion (CWD) was applied as phenomenological drying kinetic model, and its effects were perceptively identified through the starting accessibility (SWS) and the effective diffusivity Deff of water within the textured material. DIC-texturing was also recognized as a pretreatment possibly able to improve the solvent extraction of phenolic compounds. Four phenolic compounds were identified by HPLC assessments; namely hesperidin, rutin, flavone, and naringin. DIC allowed growing them from 12.10 to 65.01 (537%); from 11.47 to 27.10 (236%); from 0.006 to 0.007 (117%); and from 0.0002 to 0.00032 (160%) mg/g db, respectively. This highly significant increase of availability of these active molecules should be correlated with the presence of broken-wall cells, which Scanning electron microscopy (SEM) later, revealed and confirmed. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
35. Preparation and Characterization of Macroporous Hydrogels from Copolymers Networks.
- Author
-
Dib, Nihel, Sebba, Fatima Zohra, Sebti, Houari, and Kada, Seghier Ould
- Subjects
- *
COPOLYMERS , *HYDROGELS , *FREE radicals , *COPOLYMERIZATION - Abstract
New hydrogels based on (MAA) and (NVP) copolymers crosslinked with (BAA), were prepared by free radical cross-linking copolymerization, with a NVP percent molar composition of 10, 47.5 and 85. These hydrogels have been characterized by (FTIR), (SEM), (TGA/DSC) coupling. The results show four steps of degradation. The degradation rate is inversely proportional to the mole percent of NVP, and SEM shows that the hydrogels have a pore size between 7.14 to 13.33 µm. [ABSTRACT FROM AUTHOR]
- Published
- 2019
36. Application of the small-angle X-ray scattering technique for structural analysis studies: A review.
- Author
-
Li, Jingpeng, Jiao, Aiquan, Chen, Shuo, Wu, Zhengzong, Xu, Enbo, and Jin, Zhengyu
- Subjects
- *
SMALL-angle X-ray scattering , *X-ray diffraction , *SYNCHROTRONS , *CARBOHYDRATES , *PHYSICAL & theoretical chemistry - Abstract
Small angle X-ray scattering (SAXS) is widely used as an efficient method to analysis the structural changes. Thus, the aim of this mini-review was to summarize important information about performing SAXS technique. For more clarification, a brief introduction of the fundamental history, scattering theory, and essential structure of SAXS were presented at first. But the main focus was placed on the application of SAXS for structural analysis studies, including carbohydrate polymers, protein, and synthetic compounds. Additionally, the simultaneous performance of SAXS with other instruments was addressed to show the potential application value of SAXS technique in structural analysis field. Furthermore, the differences between SAXS and other similar techniques, including synchrotron X-ray diffraction (SXD), wide-angle X-ray scattering (WAXS), scanning Electronic Microscopy (SEM), and wide-angle X-ray diffraction (WAXD), were discussed to save time and money for studies on structural analysis. Moreover, the practical points and future perspectives of utilizing SAXS technique were put forwards based on the diagnostic vision on the development direction of SAXS technique. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
37. Comparison of power cycling reliability of flexible PCB interconnect smaller/thinner and larger/thicker power devices with topside Sn-3.5Ag solder joints.
- Author
-
Li, Jianfeng, Dai, Jingru, and Johnson, Christopher Mark
- Subjects
- *
RELIABILITY in engineering , *PRINTED circuits , *POWER semiconductors , *FINITE element method , *SCANNING electron microscopy - Abstract
The power cycling reliability of flexible printed circuit board (PCB) interconnect smaller/thinner (ST) 9.5 mm × 5.5 mm × 0.07 mm and larger/thicker (LT) 13.5 mm × 13.5 mm × 0.5 mm single Si diode samples have been studied. With the assumption of creep strain accumulation-induced fatigue cracking as the failure mechanism of the Sn-3.5Ag solder joints, finite element (FE) simulations predicted a higher power cycling reliability of soldering the flexible PCB on a ST Si diode than on a LT Si diode under similar power cycling conditions. Then the power cycling test results of 10 samples for each type are reported and discussed. The samples were constructed with commercially available ST Si diodes with 3.2/0.5/0.3 μm thick AlSiCu/NiP/Pd topside metallization and LT Si diodes with 5/0.1/1/1 μm thick Al/Ti/Ni/Ag topside metallization. In contradiction with the FE prediction, most ST Si diode samples were less reliable than those LT Si diode samples. This can be attributed to the fact that the failure of the ST diode samples was associated with the weak bonding and hence the shear-induced local delamination of the topside solder joints from the AlSiCu metallization, while the failure of the LT diode samples was mainly caused by the creep strain accumulation-induced fatigue cracking within the solder joints. Such results can be used to not only provide better understanding of the different failure mechanisms, but also demonstrate the importance of employing an appropriate topside metallization on the power devices. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
38. The Modification of Titanium Dioxide MOCVD Coating in TiAlNb after Immersion in Artificial Saliva
- Author
-
Aldea, Elena, Dicu, M. M., Gleizes, A., Demetrescu, I., Magjarevic, R., editor, Nagel, J. H., editor, Katashev, Alexei, editor, Dekhtyar, Yuri, editor, and Spigulis, Janis, editor
- Published
- 2008
- Full Text
- View/download PDF
39. Synthesis and Structural Peculiarities of the Exfoliated Graphite Modified by Carbon Nanostructures
- Author
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Yu. Sementsov, I., Prikhodko, G. P., Revo, S. L., Melezhyk, A. V., Pyatkovskiy, M. L., Yanchenko, V. V., Veziroglu, T. Nejat, editor, Yu. Zaginaichenko, Svetlana, editor, Schur, Dmitry V., editor, Baranowski, B., editor, Shpak, Anatoliy P., editor, and Skorokhod, Valeriy V., editor
- Published
- 2005
- Full Text
- View/download PDF
40. Structural and Phase Transformation in Metals at High-Speed Cutting and Tool Wear.
- Author
-
Skotnikova, M.A., Krylov, N.A., and Popov, A.A.
- Subjects
METAL cutting ,PHASE transitions ,MECHANICAL wear ,MATERIAL plasticity ,SCANNING electron microscopy - Abstract
This article adduces the experimental results of tool wear, geometry change and the structure of chips from alloys VТ23, АМc, HVG in the initial state and in the speed interval of cutting treatment equal to 2…275 m/min with attraction of transmission and scanning electronic microscopy. The interplay laws of dynamic plastic deformation and destruction on macro-, mezo- and micro-levels are established. It is shown that the formation of modulated high-tensile secondary structures in a metal blank raises protective wearproofity of the treated metal blank, but the cutting edge lowers the cutting tool wearproofity. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
41. Effect of an active label based on benzyl isothiocyanate on the morphology and ochratoxins production of Aspergillus ochraceus.
- Author
-
Clemente, Isabel, Aznar, Margarita, and Nerín, Cristina
- Subjects
- *
ASPERGILLUS , *MORPHOLOGY , *ISOTHIOCYANATES , *OCHRATOXINS , *METABOLISM , *FOOD packaging , *SCANNING electron microscopy , *PHYSIOLOGY - Abstract
The aim of this work was the study of the main effects of benzyl isothiocyanate (BITC) on A. ochraceus morphology and on its production metabolism of ochratoxins. This compound was evaluated as active agent of an antimicrobial label in food packaging. Microbiological studies showed a slowdown in mould growth when the active material was applied to A. ochraceus and the presence of three different areas of growth. Scanning electron microscopy was successfully used to demonstrate the mode of action of BITC on this strain. A. ochraceus exhibited modifications in morphology compared to the control samples such as the disappearance of sclerotia or cleistothecia An extraction protocol and an analytical method by UPLC-MS/MS to determine ochratoxins (OTs) was developed. The results showed that all these morphological changes were related to a decrease on OTs production, both ochratoxin A (OTA) and ochratoxin B (OTB). The presence of BITC caused a great decrease on OTA that modified the OTA/OTB ratio, increasing the OTB proportion. Furthermore, the active packaging also modified the production of other secondary metabolites. The morphological and metabolic effects observed, as well as the relationship between them, are of great interest since they have not been reported before for A. ochraceus . [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
42. A comparative study of mud-like and coralliform calcium carbonate gallbladder stones.
- Author
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Ma, Rui‐Hong, Luo, Xiao‐Bing, Wang, Xiao‐Feng, Qiao, Tie, Huang, Hai‐Yi, and Zhong, Hai‐Qiang
- Abstract
To gain insight to underlying mechanism of the formation of calcium carbonate (CaCO
3 ) gallbladder stones, we did comparative study of stones with mud appearance and those with coralliform appearance. A total of 93 gallbladder stones with mud appearance and 50 stones with coralliform appearance were analyzed. The appearance, color, texture, and the detection of Clonorchis sinensis eggs by microscopic examination were compared between the two groups. Then, the material compositions of stones were analyzed using Fourier Transform Infrared spectroscopy and the spectrogram characteristics were compared. Moreover, microstructure characteristics of the two kinds of stones were observed and compared with Scanning Electron Microscopy. Mud-like gallbladder stones were mainly earthy yellow or brown with brittle or soft texture, while coralliform stones were mainly black with extremely hard texture, the differences between the two groups was significant ( p < .05). The analytic results of FTIR spectroscopy showed that 95.7% (89/93) of the mud-like gallbladder stones were CaCO3 stones, and mainly aragonite; while all of the coralliform stones were CaCO3 stones, and mainly calcite ( p < .05). Meanwhile, microscopic examination indicated that the detection rate of Clonorchis sinensis eggs in mud-like CaCO3 stones was lower than that in coralliform CaCO3 stones ( p < .05), and that in aragonite CaCO3 stones was lower than that in calcite CaCO3 stones( p < .05). Mud-like CaCO3 stones mainly happened to patients with cystic duct obstruction. Clonorchis sinensis infection was mainly associated with coralliform (calcite) CaCO3 stones. Cystic duct obstruction was mainly associated with mud-like (aragonite) CaCO3 stones. [ABSTRACT FROM AUTHOR]- Published
- 2017
- Full Text
- View/download PDF
43. Interconnect Materials Enabling IGBT Modules to Achieve Stable Short-Circuit Failure Behavior.
- Author
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Li, Jianfeng, Corfield, Martin, Johnson, Christopher Mark, and Yaqub, Imran
- Subjects
- *
INSULATED gate bipolar transistors , *SHORT circuits , *FAILURE analysis , *INTEGRATED circuit interconnections , *FINITE element method , *ELECTRONICS packaging , *OVERCURRENT protection - Abstract
Insulated gate bipolar transistor (IGBT) modules, which can fail to stable short-circuit mode, have major applications in electricity network-related fields. Sn-3.5Ag solder joints and sintered Ag joints for the die attachment and Mo, Cu, Sn-3.5Ag, Al, and Ag foils for the top side insert (TSI) material in press pack like single IGBT samples have been investigated using overcurrent and current passage tests. The results reveal that Sn-3.5Ag solder joints in combination with Sn-3.5Ag, Al, or Ag foils can be employed to achieve stable short-circuit failure mode, where the best results are achieved with Ag foils. This can be attributed to the formation of conductive networks/channels through the failed IGBT and good alignment between the residual TSI material and the failed IGBT. [ABSTRACT FROM PUBLISHER]
- Published
- 2017
- Full Text
- View/download PDF
44. Mechanical, microstructural and energetic evaluation of conventional and one-part alkali-activated mixtures with raw sugarcane bagasse ash.
- Author
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Lima, Victor M.E., Estolano, Amanda M.L., Almeida, Yeda M.B., Henrique, Mariana A., Araújo, Fernanda W.C., and Melo Neto, Antonio A.
- Subjects
- *
BAGASSE , *SUGARCANE , *COMPRESSIVE strength , *X-ray diffraction , *ENERGY industries , *MIXTURES , *MORTAR - Abstract
• A new strategy for one-part mixtures activated by sodium metasilicate is suggested. • The use of 10% unground SBA improved the compressive strength at early ages. • Ca/Si ratio of C-(A)-S-H matrices decreased with the incorporation of 50% SBA. • The incorporation of unground SBA reduced costs and saved energy. This study aimed to develop eco-friendly alkali-activated mixtures utilizing blast furnace slag (BFS) and unground sugarcane bagasse ash (SBA). One-part mixtures comprising BFS, SBA, and sodium metasilicate as dry materials were compared to conventional mixtures. Mortars and pastes were prepared with SBA replacement ratios up to 70%. At 3-days compressive strength, an increase for mixtures with 10% and 30% SBA was observed. The techniques of XRD, TG, FTIR and SEM were used to identify chemical and morphological changes caused by SBA incorporation. Utilizing raw SBA eliminated processes, saved power consumption and made employing this waste feasible. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
45. Effect of Cleanser Solutions on the Retention Force of O’ring Attachment: An in Vitro Study
- Author
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Luis Geraldo Vaz, Ana Paula Macedo, Valéria Oliveira Pagnano, Daniela Nair Borges Felipucci, Luciana Costa Crizóstomo, Suleima do Vale Alves, Patricia Almeida Curylofo, Universidade de São Paulo (USP), and Universidade Estadual Paulista (Unesp)
- Subjects
Dental Stress Analysis ,Nitrile ,Sodium Hypochlorite ,Scanning electron microscope ,0206 medical engineering ,Analytical chemistry ,02 engineering and technology ,law.invention ,03 medical and health sciences ,chemistry.chemical_compound ,Overdenture ,0302 clinical medicine ,Cleanser ,law ,Tensile Strength ,Materials Testing ,Ultimate tensile strength ,Scanning electronic microscopy ,In vitro study ,General Dentistry ,Chemistry ,Denture cleanser ,030206 dentistry ,Denture, Overlay ,Denture Retention ,020601 biomedical engineering ,Retention ,Sodium hypochlorite ,Dental Prosthesis, Implant-Supported ,O-ring ,Fluoride - Abstract
The aim of this study was to evaluate the effect of cleaning solutions on the retention force of o-ring-type overdenture attachments. The effect of four solutions on nitrile rings were evaluated: Cepacol (C), Cepacol with fluoride (CF), Listerine (L) and 0.05% sodium hypochlorite (SH); deionized water (DW) was used as a control. Matrices containing two implants and abutments and acrylic specimens with the metal capsules were obtained and divided into the groups. A simulation of 90 overnight immersions (8 h) was performed, and the tensile strength value was obtained at the beginning (T0) and in every 30 days (T1, T2 and T3) (n=6). In order to analyze o-ring surface damage after the immersions, a scanning electron microscopy (SEM) was used (n=1). For statistical analysis of the results, analysis of variance (ANOVA) and multiple comparisons with Bonferroni adjustment (test power=1.000; a=0.05) were used. There was a significant difference for the factors time (p
- Published
- 2020
- Full Text
- View/download PDF
46. Эффективность комбинированной терапии деструктивных форм периодонтита
- Subjects
kollapan k ,ultrasound ,Dentistry ,pmax newtron ,RK1-715 ,periodontitis ,scanning electronic microscopy - Abstract
Possibilities of the modern ultrasonic equipment promote deeper diffusion hydroxyapatite containing preparations in dentine tubules and lateral deltas of root channels of teeth, by results of scanning electronic microscopy. Measurement of density profile provides an objective estimation of features of regeneration of a bone fabric at stages of dynamic radiological control. In work the nearest and remote results of treatment of 93 patients with chronic apical periodontitis with which treatment by an advanced method of application of a preparation «Kollapan-gel K» in a combination to ultrasound and further by the analysis of density profile of roentgenograms the program «SIDEXIS XG» has been spent are considered.
- Published
- 2020
47. Toxicological and ultrastructural analysis of the impact of pesticides used in temperate fruit crops on two populations of Chrysoperla externa (Neuroptera, Chrysopidae) Análises toxicológica e ultra-estrutural do impacto de agrotóxicos usados no cultivo de frutíferas de clima temperado sobre duas populações de Chrysoperla externa (Neuroptera, Chrysopidae)
- Author
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Alexandre Pinho de Moura, Geraldo Andrade Carvalho, Luciano Veiga Cosme, Eduardo Alves, Marcos Botton, and Patrícia Sobral Silva
- Subjects
Crisopídeos ,efeitos adversos ,manejo integrado de pragas ,microscopia eletrônica de varredura ,inimigo natural ,Green lacewings ,integrated pest management ,natural enemy ,scanning electronic microscopy ,side-effects ,Zoology ,QL1-991 - Abstract
This study aimed to evaluate the effects of (g a.i. L-1) abamectin (0.02), carbaryl (1.73), sulphur (4.8), fenitrothion (0.75), methidathion (0.4), and trichlorfon (1.5) on the survival of larvae and pupae, on the oviposition of adults and hatching of eggs from treated Chrysoperla externa third-instar larvae from two different populations (Bento Gonçalves and Vacaria, Rio Grande do Sul State, Brazil). Morphological changes caused by abamectin to eggs laid by C. externa from Vacaria population were evaluated by mean of ultrastructural analysis. The pesticides were applied on glass plates. Distilled water was used as control. For the evaluation of larvae mortality, a fully randomized experimental design in a 2 x 7 (two populations x seven treatments) factorial scheme was used, whereas for the effects of the compounds on oviposition capacity and egg viability, a 2 x 4 factorial scheme was used. Carbaryl, fenitrothion, and methidathion caused 100% mortality of larvae. Abamectin reduced the hatching of eggs from treated third-instar larvae of both populations; however, this pesticide presented highest toxicity on insects from Vacaria. The ultrastructural analysis showed that abamectin caused malformations in micropyle and in chorion external surface of C. externa eggs. Based in the total effect (E), carbaryl, fenitrothion, and methidathion are harmful to C. externa; trichlorfon is harmless to third-instar larvae, while abamectin and sulphur are harmless and slightly harmful to third-instar larvae from Bento Gonçalves and Vacaria, respectively.Avaliaram-se os efeitos de (g i.a. L-1) abamectina (0,02), carbaril (1,73), enxofre (4,8) fenitrotiona (0,75), metidationa (0,4) e triclorfom (1,5) sobre a sobrevivência de larvas e pupas, na oviposição de adultos e viabilidade de ovos de Chrysoperla externa de duas populações (Bento Gonçalves e Vacaria, Rio Grande do Sul). Alterações morfológicas causadas por abamectina em ovos depositados por C. externa da população de Vacaria foram avaliadas por meio de análises ultra-estruturais. Os agrotóxicos foram aplicados sobre placas de vidro. Água destilada foi utilizada como testemunha. Para avaliação da mortalidade de larvas utilizou-se delineamento experimental inteiramente ao acaso, em esquema fatorial 2 x 7 (duas populações x sete tratamentos) e para avaliação dos efeitos dos compostos sobre a capacidade de oviposição e viabilidade de ovos utilizou-se esquema fatorial 2 x 4. Carbaril, fenitrotiona e metidationa causaram 100% de mortalidade das larvas. Abamectina reduziu a viabilidade de ovos de C. externa, provenientes de larvas de terceiro ínstar de ambas as populações; entretanto, apresentou toxicidade mais elevada sobre insetos de Vacaria. Análises ultra-estruturais evidenciaram que abamectina causou deformações na micrópila e na superfície externa do córion de ovos de C. externa. Baseando-se no efeito total (E), carbaril, fenitrotiona e metidationa são prejudiciais a C. externa; triclorfom é inócuo, enquanto abamectina e enxofre são inócuos e levemente prejudiciais a larvas de terceiro ínstar oriundas de Bento Gonçalves e Vacaria, respectivamente.
- Published
- 2011
48. Efeitos do pH, acidez e alcalinidade na microbiota de um reator anaeróbio de manta de lodo (UASB) tratando efluentes de suinocultura
- Author
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Erlon Lopes Pereira, Cláudio Milton Montenegro Campos, and Fabrício Moterani
- Subjects
archeas methanogenic ,scanning electronic microscopy ,UASB ,Environmental sciences ,GE1-350 - Abstract
The anaerobic processes used for treating wastewater have been often applied mainly for optimizing treatment systems. Among many of these systems, the UASB is one of the most successfully used. This type of reactor presents a good condition for microorganisms development, and therefore, for organic matter degradation. As a result, the goal of this research was to evaluate the effect of parameters, such as: temperature, pH, acidity and alkalinity on the microorganisms consortia, acclimatized in an UASB reactor, and simultaneously, observing the sludge morphology through a scanning electronic microscopy (SEM), in order to identify the response of the bacteria consortia under this environmental circumstances. The biomass operated under a mesophilic temperature, varying from 190C to 210C. The maximum concentration of volatile acids was 100 mg L-1, and the volumetric organic loading rate was 59 kgCOD m-3d-1. The total alkalinity concentration values were between 2500 and 5550 mgCaCO3 L-1. The average pH value of the sludge was 7.3. Under these conditions it was observed the development of a well acclimatized granular biomass, composed mainly of filamentous bacteria.
- Published
- 2009
49. Effects of pH, acidity and alkalinity on the microbiota activity of an anaerobic sludge blanket reactor (UASB) treating pigmanure effluents
- Author
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Fabricio Moterani, Cláudio Milton Montenegro Campos, and Erlon Lopes Pereira
- Subjects
archeas methanogenic ,scanning electronic microscopy ,UASB ,Environmental sciences ,GE1-350 - Abstract
The anaerobic processes used for treating wastewater have been often applied mainly for optimizing treatment systems. Among many of these systems, the UASB is one of the most successfully used. This type of reactor presents a good condition for microorganisms development, and therefore, for organic matter degradation. As a result, the goal of this research was to evaluate the effect of parameters, such as: temperature, pH, acidity and alkalinity on the microorganisms consortia, acclimatized in an UASB reactor, and simultaneously, observing the sludge morphology through a scanning electronic microscopy (SEM), in order to identify the response of the bacteria consortia under this environmental circumstances. The biomass operated under a mesophilic temperature, varying from 190C to 210C. The maximum concentration of volatile acids was 100 mg L-1, and the volumetric organic loading rate was 59 kgCOD m-3d-1. The total alkalinity concentration values were between 2500 and 5550 mgCaCO3 L-1. The average pH value of the sludge was 7.3. Under these conditions it was observed the development of a well acclimatized granular biomass, composed mainly of filamentous bacteria.
- Published
- 2009
- Full Text
- View/download PDF
50. Utilização da microscopia eletrônica de varredura como ferramenta de avaliação da estrutura do tecido de abacate 'quintal' após danos mecânicos Use of scanning electronic microscopy as tool of the tissue structure evaluation of quintal ' avocado tissue structure after mechanical injuries
- Author
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Juliana Sanches, José Fernando Durigan, and Jaime Maia dos Santos
- Subjects
compressão ,corte ,impacto ,microscopia eletrônica de varredura ,Persea americana ,compression ,cut ,impact ,scanning electronic microscopy ,Plant culture ,SB1-1110 - Abstract
Avaliaram-se os efeitos de injúrias mecânicas, por impacto, compressão e corte nas estruturas celulares de abacates 'Quintal'. Na injúria por impacto, eles foram deixados cair, em queda livre, de uma altura de 2,00 m, sobre os lados opostos, de sua região equatorial; na compressão, foram colocados sob um peso de 117,6 N, por 24 horas, o que provocou duas lesões opostas, no sentido longitudinal; e os cortes foram aplicados em número de quatro, longitudinalmente, com 40 mm de comprimento e 4 mm de profundidade, nos lados opostos dos frutos. Após 5 dias de armazenamento, sob condições de ambiente (25ºC e 60% UR), procedeu-se à verificação das estruturas celulares através de microscopia eletrônica de varredura. A microscopia eletrônica de varredura indicou que os abacates injuriados por compressão e impacto, embora sem lesões aparentemente visíveis, apresentavam desordem celular em suas estruturas.This work aimed to evaluate the effects of mechanical injuries, by impact, compression and cut in the cellular structures of 'Quintal' avocados. In the injury by impact, they were submitted, by free fall, to a height of 2.00 m, in opposed sides of their equatorial area; in the compression, they were submitted by a weight of 117.6 N for 24 hours, and it provoked two opposite lesions in the longitudinal area; and the cuts were longitudinally applied at number of four, with 40 mm of length and 4 mm of depth in the opposed sides of the fruits. After 5 days of storage, under the laboratory conditions (25ºC and 60% RH), the verification of the cellular structures was proceeded through scanning electron microscopy, which indicated that the injuried avocados by compression and impact, although without apparently visible lesions, presented cellular disorder in their structures.
- Published
- 2007
- Full Text
- View/download PDF
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