Clear Bands Research Articles

Genome sequence analysis of Malayan pangolin (Manis javanica) forensic samples reveals the presence of Paraburkholderia fungorum sequences.

The Malayan pangolin (Manis javanica) is a placental mammal and is listed as Critically Endangered on the IUCN Red List of Threatened Species. Most previous attempts to breed pangolins in captivity have met with little success because of dietary issues, infections, and other complications, although a previous study reported breeding pangolins in captivity to the third generation. In our previous pangolin genome sequencing data analysis, we obtained a considerable amount of bacterial DNA from a pregnant female Malayan pangolin (named "UM3"), which was likely infected by Paraburkholderia fungorum-an agent of biodegradation and bioremediation in agriculture. Here, we further confirmed and characterized this bacterial species using PCR, histological staining, whole-genome sequencing, and bioinformatics approaches. PCR assays with in-house designed primer sets and 16S universal primers showed clear positive bands in the cerebrum, cerebellum, lung, and blood of UM3 suggesting that UM3 might have developed septicaemia. Histological staining showed the presence of Gram-negative rod-shaped bacteria in the pangolin brain and lungs, indicating the colonization of the bacteria in these two organs. In addition, PCR screening of UM3's fetal tissues revealed the presence of P. fungorum in the gastrocnemius muscle, but not in other tissues that we examined. We also sequenced and reconstructed the genome of pangolin P. fungorum, which has a genome size of 7.7 Mbps. Our study is the first to present detailed evidence of the presence of P. fungorum in a pangolin and her fetus (although preliminary results were presented in our previous article). Here, we raise the concern that P. fungorum may potentially infect humans, especially YOPI (young, old, pregnant, and immunocompromised) people. Therefore, caution should be exercised when using this bacterial species as biodegradation or bioremediation agents in agriculture.

Evaluation of The Extract of Microalgae and Its Fatty Acids on Candida spp. Isolated from Renal Impairment Patients

Background: Due to harmful microorganisms’ resistance to many antibiotics, alternative solutions are required to eradicate them. Method: Chlorella vulgaris and Oscillatoria limnetica, two species of microalgae, were isolated for this investigation from the surrounding aquatic environment. The hexane extract of these two algae was tested in vitro by using two activities: antifungal and antibiofilm, against two species of Candida (Candida albicans and Candida glabrata), which were clinically isolated from 100 renal impairment patients, and it was diagnosed by some biochemical test. Results: Fourier Transform Infrared Spectroscopy analysis determined 15 clear bands from (3381.21- 671.23 cm-1) for Chlorella vulgaris, and 12 clear bands from (2960.73- 1261.45 cm-1) for Oscillatoria limnetica. The Gas chromatography-mass spectrometry showed important chemical compounds for both microalgae which: p-Xylene, Dihydrocoumarin, 4,4,5,7,8-pentamethyl, Butylated Hydroxytoluene, 1,4-Benzenediol, 2,5-bis (1,1-dimethylethyl), Eicosane, n-Hexadecanoic acid, 9-Octadecenoic acid, (E), 2-hydroxy-1-(hydroxymethyl) ethyl ester, Bis(2-ethylhexyl) phthalate, 2,3-dihydroxypropyl ester, diethylhydroxylamine, Ethylbenzene, Benzaldehyde, 9,12,15- Octadecatrienoic acid, methyl ester, Hexadecanoic acid, Phytol, Methyl stearate. The results showed that crude hexane extract of Chlorella vulgaris was better than Oscillatoria limnetica as an antifungal, and the percent of antibiofilm was 79% with Chlorella vulgaris, while 77.7% with Oscillatoria limnetica. The rich fatty acids in Chlorella vulgaris have been partially purified from it and applied with two concentrations (10 and 100 mg/ml) as a good antifungal and antibiofilm with a percent of 81.667% for the two concentrations. Conclusion: With the global rise in antibiotic resistance, these algae have demonstrated their value as projects for alternative medicines

Trompe l’oeil fossils from Silurian quartzites of Sierra Morena (South Spain): a taphonomic approach on the study of a coral-like structure

ABSTRACT Some circular fossils showing radial structures concentrated in a small area have been recorded from the Criadero Quartzite, 1 km north from El Centenillo village (Iberian Central Zone, SE Spain). The fossils resembling cnidarians have been studied in detail, both at the field and in the laboratory. The specimens have been preserved in thick-grained quartz sandstones. They were analysed in thin sections and rock samples using optical microscopy, micro-reflectance spectroscopy, Fourier transform infrared–attenuated total reflectance spectroscopy, scanning electron microscopy with energy-dispersive X-ray spectroscopy and epifluorescence microscopy. The radial structure is composed of ridges and grooves, which correspond to clear and dark ochre bands filled with middle-sized, angular-elongated quartz grains without tractive structures. Mineralogical analyses reveal that composition is based on quartz and illite in both areas. The morphological and compositional features of the fossils have been compared with a set of ichnofossils of multiple taxonomic origins and ages without conclusive results. The preservation is probably produced by the existence of microbial mats on the sand floor and the impression of moulds by authigenic cementation by an unidentified organism. To elucidate the nature of the producer, potentially soft-bodied cnidarian, including fossil medusae and sea anemone, further investigations are needed.

Assessment of the genetic fidelity of true-to-type regenerants of medicinal plant Rheum emodi using RAPD and ISSR molecular markers

Rheum emodi commonly known as rhubarb is mainly found in Northern Himalayas. It is a valuable medicinal plant having major pharmacological activities such as antimicrobial, anticancer, antioxidant, anti-inflammatory and is used extensively as purgative, stomachic and astringent tonic and improves gastro related problems. This herb is used by the local communities for medicinal as well as common eating purpose. This leads to its immense decline in its natural habitat and now this herb falls under threatened species and demands conservation. In this prospective, an efficient in vitro propagation method from callus culture has been achieved using leaf explants excised from the juvenile plant of R. emodi. Murashige and Skoog (MS) basal medium was used for regeneration procedure with different concentration of phytohormones. Maximum frequency of callus formation (84.44±0.27%) was observed in MS+36.19μM (2, 4-D) in combination with 11.10μM (BAP). The highest percentage of adventitious shoot regeneration was observed as 75.56±0.27% and the maximum number of shoots per explant that is 3.67±0.27 was achieved on MS basal medium containing BAP (35.5 μM) and Kn (11.61 μM). The maximum frequency of rooting was observed in MS full strength media + IAA (28.55 μM) + BAP (8.88 μM). The highest frequency of roots per shoot was observed as 5.0±0.47 with an average root length of 11±1.25mm. For ascertaining the clonal fidelity, 20 ISSR markers and 15 RAPD markers were assayed and employed to validate the true-to-type regenerants of Rheum emodi. Out of 15 RAPD and 20 ISSR markers, 7 markers and 15 markers produced distinct, clear and scorable bands with an average of 4.5 bands and 4.4 bands per marker respectively among the tissue cultured progenies. For each primer, the banding pattern was uniform and comparable to mother plant and showed about 99% homology. All the markers produce the monomorphic bands and no variation was detected among the micropropagated plants. Thus, the analysis of ISSR and RAPD patterns revealed that the bands were shared by both in vitro raised plants and parent clump confirming the genetic stability. DNA based molecular markers have proved to be versatile tools in diverse fields of biology. These markers proved to be model tools for routine analysis of clonal fidelity of micropropagated plants prior to commercialization.

Evaluation of Easy and Economic Protocols for High Quality Genomic DNA Extraction and Sex Determination in Papaya Using SCAR Markers

Rapid and precise identification of three sex types (male, hermaphrodite and female flowers) is the key in achieving good returns in papaya (Carica papaya L.) cultivation. This study presents a simple, reliable, fast and cost-efficient DNA isolation protocol and a rapid and precise method of sex determination in papaya. Three DNA isolation protocols viz., CTAB method, Modified Dellaporta method and BioBasic DNA isolation kit were comparatively evaluated for their simplicity, economic, DNA quantity and purity. Among them, CTAB method was regarded as relatively economic, with a cost of Rs. 11.80943 per sample with higher amount of DNA (4667.4 µg/ µl). However, it was noticed that DNA isolation with the BioBasic kit was fastest method, which took only 6 hours 7 minutes. On the other hand, relatively better DNA purity was noticed with the Modified Dellaporta method (average ratio of absorbance at 260 nm and 280 nm range between 1.8-2.0) and yielded clear, intact and distinct DNA bands. Hence, Modified Dellaporta method is suggested as an ideal DNA isolation protocol for papaya. Molecular markers (such as SCAR derived from RAPD T12, W11, NAPF-2 and PKBT-4) were employed in this study to identify the sex type and they have successfully distinguished between male and hermaphrodite plants in both dioecious and gynodioecious varieties; especially, NAPF-2 has successfully distinguished male in dioecious varieties. Evaluation of different kinds of molecular markers has shown that the SCAR marker T12 can be used as reliable marker for rapid and precise identification of papaya sex type.

Band-Gap Energy and Electronic d-d Transitions of NiWO4 Studied under High-Pressure Conditions.

We report an extensive study of the optical and structural properties of NiWO4 combining experiments and density functional theory calculations. We have obtained accurate information on the pressure effect on the crystal structure determining the equation of state and compressibility tensor. We have also determined the pressure dependence of the band gap finding that it decreases under compression because of the contribution of Ni 3d states to the top of the valence band. We report on the sub-band-gap optical spectrum of NiWO4 showing that the five bands observed at 0.95, 1.48, 1.70, 2.40, and 2.70 eV correspond to crystal-field transitions within the 3d8 (t2g6eg2) configuration of Ni2+. Their assignment, which remained controversial until now, has been resolved mainly by their pressure shifts. In addition to the transition energies, their pressure derivatives are different in each band, allowing a clear band assignment. To conclude, we report resistivity and Hall-effect measurements showing that NiWO4 is a p-type semiconductor with a resistivity that decreases as pressure increases.

Genetic diversity analysis and fingerprints of Chrysanthemum×morifolium based on SSR molecular markers

The present study aims to explore the genetic diversity of germplasm resources of Chrysanthemum×morifolium (hereinafter, C.×morifolium) at the molecular level and to establish a fingerprint database of C.×morifolium varieties. We employed 12 pairs of primers with high levels of polymorphism, clear bands, and high degrees of reproducibility to analyze the SSR molecular markers and genetic diversity of 91 C.×morifolium materials and 14 chrysanthemum- related materials. With regard to constructing the fingerprints of the tested materials, we chose 9 pairs of core primers. The findings revealed that 12 primer pairs detected 104 alleles in 105 samples, ranging from 2 to 26. The average number of observed alleles (Na) per site was 9.25. The average number of effective alleles (Ne) per site was 2.745 6, with its range being 1.276 0 to 4.742 5. Shannon genetic diversity index (I) values ranged between 0.513 3 and 2.239 9 (M=1.209 0). Nei's gene diversity index (H) ranged between 0.216 3 and 0.789 1 (M=0.578 0). The observed heterozygosity (Ho) ranged between 0.223 3 and 0.895 2 (M=0.557 5). The expected heterozygosity (He) ranged between 0.217 4 and 0.793 3 (M=0.580 8). The polymorphism information content (PIC) ranged between 0.211 5 and 0.774 0 (M=0.532 9). The genetic similarity (GS) ranged between 0.228 5 and 1.000 0 (M=0.608 3). Cluster analysis revealed that when the genetic distance (GD) equals to 0.30, the tested materials can be classified into 2 groups. When the GD equals to 0.27, the first group can be divided into 6 subgroups; accordingly, 105 tested materials can be divided into 7 subgroups. The cophenetic correlation test was carried out based on the cluster analysis, and the corresponding results showed that the cluster map correlated with the genetic similarity coefficient (r=0.952 73). According to the results of Structure population analysis, we obtained the optimal population number, with the true number of populations (K) being 3 and the population being divided concerning Q≥0.5. Three subgroups, i.e., Q1, Q2 and Q3, included 34, 33 and 28 germplasms, respectively, and the remaining 10 germplasms were identified as the mixed population. During the experiment, 9 pairs of core primers were screened among the total of 12 for a complete differentiation regarding 105 tested materials, and the fingerprints of 91 C.×morifolium materials and 14 chrysanthemum-related materials were further constructed. Overall, there were significant genetic differences and rich genetic diversity among C.×morifolium materials, which would shed light on the garden application and variety selection fields of C.×morifolium. The fingerprint database of 105 C.×morifolium varieties and chrysanthemum-related species may provide technical support for future research regarding the identification and screening system of C.×morifolium varieties.

Interaction between 1/2[formula omitted]110[formula omitted]{001} dislocations and {110} prismatic loops in uranium dioxide: Implications for strain-hardening under irradiation

Plasticity of irradiated UO2 is of major interest to improve the risk assessment of the nuclear fuel cladding failure in the case of design basis accidents. In this study, we investigate the main irradiation-hardening processes induced by {110} irradiation loops interacting with glissile dislocations of the primary slip system, 1/2<110>{001}, of UO2. The interactions are simulated at two scales using molecular dynamics and discrete dislocation dynamics, to characterise local interactions and identify strengthening configurations as a function of the dislocation-irradiation loop geometry. In particular, we show that 1/2<110>{001} screw dislocations can be strongly pinned by helical turn configurations. Statistical large-scale discrete dislocation simulations are performed to investigate the collective behaviour of a large density of irradiation defects and quantify irradiation hardening. Several microstructural processes including loop drag and shovelling are observed and their involvement in clear band formation and hardening of UO2 fuel at high temperature is discussed.

Establishment of a PCR-SSP method for the simultaneous amplification and identification of the presence of KIR genes

To develop a polymerase chain reaction-sequence specific primer (PCR-SSP) method for simultaneous amplification and identification of the KIR genes among Chinese population. Peripheral blood samples from 132 healthy donors who had given blood at Shenzhen Blood Center from January 2015 to November 2015 were selected as the study subjects. Based on the polymorphism and single nucleotide polymorphism (SNP) information of high-resolution KIR alleles in the Chinese population and the IPD-KIR database, specific primers were designed to amplify all the 16 KIR genes and the 2DS4-Normal and 2DS4-Deleted subtypes. The specificity of each pair of PCR primers was verified by using samples with known KIR genotypes. During PCR amplification of the KIR gene, co-amplification the fragment of human growth hormone (HGH) gene by multiplex PCR was used as the internal control to prevent false negative results. A total of 132 samples with known KIR genotypes were randomly selected for blind inspection to verify the reliability of the developed method. The designed primers can specifically amplify the corresponding KIR genes, with clear and bright bands for the internal control and KIR genes. The results of detection are fully consistent with the known results. The KIR PCR-SSP method established in this study can yield accurate results for the identification of the presence of KIR genes.

Amplification of CHD-1 gene fragment in Z and W sex chromosomes of Cemani chicken using a different set of PCR primers

Cemani chicken is a local breed of Indonesian chicken known for its mystical appearance. Selecting sex earlier is essential for the breeding program to determine the population structure. Instead of using phenotype, sexing in birds can be done molecularly by employing the variation of the CHD-1 gene, which belongs to the Z chromosome. Five primers (pair), namely AVP2 and AVP8; CHD1F and CHD1R; AV1237L and AV1272H; CHDZ and CHDW, then AV2550F and AV2718R, were employed to amplify the CHD-1 gene in PCR reaction followed with electrophoresis analysis. Cemani chicken blood was collected from the Bracial vein, followed by DNA extraction. Two primers set, CHD1F and CHD1R, and AV2550F and AV2718R, were able to amplify the CHD-1 gene and distinguish the difference between male (ZZ) vs. female (ZW) chromosome by showing two clear DNA bands in the female source sample and one band in the male sample. Meanwhile, the AVP2 and AVP8, AV1237L, and AV1272H, only show one clear band in both female and male source samples, and no bands resulted from using CHDZ and CHDW primer. Two sets of primers were able to amplify the CHD-1 gene fragment using PCR and amplified for further molecular sex determination in Cemani chicken.

Evaluating the Clinical Application of Automatic Chromosome Harvesting for Prenatal Karyotype Analysis.

Objective: The clinical value of an automatic chromosome harvester was evaluated, which included a comparison between the manual and automatic harvesting for the isolation of amniotic fluid cell chromosomes. Methods: Amniotic fluid samples from 96 high-risk gravida cases identified at 17-25 weeks treated at the Prenatal Diagnostic and Reproductive Center from June to July 2022 were collected. These samples underwent both manual and automatic chromosome collection, and their harvest time and number of amniotic cells were compared. These chromosomes were then used to produce karyotypic data for each sample using an automatic chromosomal karyotype analysis system, scan karyotype. Results: The average automatic harvesting time per sample, 3.92 min, was significantly lower than that of the manual harvesting, 7.89 min (p < 0.001). In addition, the average number of cells from the automatic harvesting (4.16 × 106 pieces) was significantly increased when compared with those of the manual group (2.10 × 106 pieces; p < 0.001). Further karyotyping revealed that both sets of chromosomes produced clear bands and good dispersion data, producing no significant differences in these evaluations (p > 0.05). However, the number of analyzable karyotypes obtained using the automatic harvester was significantly higher than those of the manual harvesting (p < 0.001). Conclusions: The automatic chromosome harvester can effectively save time, manual labor and consumables, harvest more analyzable karyotypes, and improve the efficiency of clinical diagnosis. The automatic chromosome harvester is highly stable and repeatable, which has the potential to help achieve large-scale standardized chromosome harvesting and is worthy of widespread clinical promotion.

Detection of exopolysaccharides (algD, pelF, and pslD) genes in burn wound Pseudomonas aeruginosa isolates

Abstract Background: Pseudomonas aeruginosa biofilm is an essential component of virulence that plays a significant role in antimicrobial resistance and chronic burn wound infections. Objective: This study aimed to investigate the biofilm formation capacity of P. aeruginosa isolated from chronic burn wound from January to May 2022 by biochemical and molecular techniques. Materials and Methods: Quantification of biofilm was performed based on tube method for local isolates of P. aeruginosa after growing on brain heart Broth. The genes encoding exopolysaccharides (algD, pelF, and pslD) were targeted by using conventional polymerase chain reaction (PCR). Results: The results showed that 92.6% of isolates were biofilm former, interestingly 68% of isolates were considered as strong former comparing with other biofilm categories. Gel electrophoresis result of PCR products presented clear bands for algD and psID genes with percentages (96%) and (3.7%) respectively. However, there was no PCR product for pelf gene among all isolates. Conclusion: The prevalence of algD, the large operon necessary for alginate production, was high among P. aeruginosa biofilm producer in this study and it can be an essential agent in the pathogenicity of P. aeruginosa burn wound infections comparing with other biofilm genes (pelF and pslD) of exopolysaccharide structure.

Characteristics of Vitamin D3 Receptor Genotypes in T2DM of Iraqi Obese Women

Objective: This study aims to examine the association between the (rs1544410) polymorphism of the VDR gene with the pathogenesis of T2DM in Iraqi obese women.&#x0D; Methods: A case-control study was performed on 50 patients with T2DM and 50 apparently healthy subjects who were admitted to Al-Hussein Teaching Hospital and Al-Hassan Center of Diabetes and Endocrinology unit / Kerbala health directorate – Iraq during (April 2022 – March 2023). The T2DM groups were divided into two groups, 25 obese and 25 non-obese; the control group was divided into 25 obese and 25 non-obese as apparently healthy groups. The ELISA Kit was used to measure serum 25(OH)D3, heat shock protein-70, VDBP, insulin and C-peptide. Also HbA1c% and insulin resistance (HOMA-IR) were evaluated. The vitamin D3 receptor gene (VDR) variant and the SNP (rs1544410) polymorphism was determined using allele specific polymerase chain reaction, 1.5% agarose gel electrophoresis and then visualized by gel photo-documentation system.&#x0D; Results: The result of vitamin D3 variants genotype (rs 1544410) was a clear band with a molecular size of 200 bps. The size of the amplicon was determined by compare with DNA ladder 100 - 1500 bp. The result of the comparison between observed and anticipated values for SNIP with (rs 1544410) in the tested population was statistically significant, P= &lt; 0.001 and the difference between demographic characteristics and (rs 1544410) SNP, age and BMI shows non-significant difference among all groups. The difference between biomarkers and (rs1544410) SNP was performed using one-way ANOVA test to compare the mean levels of HSP-70, VDBP, C-peptide, RBC and HbA1c% which shown a non-significant difference among the variants of VDBP Genotype (rs1544410) in obese women (patients and control) studied groups, p value &gt; 0.05. &#x0D; Conclusion: The logistic analysis of the (rs1544410) SNP of the patients concluded that HSP-70, VDBP, and C-peptide level was no significantly related to the also C-peptide, was shown to be a related risk factor to both CT and CT alleles (1.003, p &gt; 0.05) in comparison with CC alleles. Furthermore, HbA1c% level was demonstrated to be related as a risk factor for the CG allele in comparison with CC and GG alleles (1.009, p &lt; 0.05).

Comparative analysis indicates a simple protocol for DNA extraction of the aromatic plant Lippia alba

An efficient method of genomic DNA extraction that provides high quality and yield is a crucial pre-requisite and limiting factor in plant genetic analysis. However, pure genomic DNA can be challenging to obtain from some plant species due to their sugar and secondary metabolite contents. Lippia alba is an important aromatic and medicinal plant, chemically characterized by the presence of tannins, flavonoids, anthocyanins, and essential oils, which interfere with the extraction of pure genomic DNA. In this scenario, optimizing the extraction methods and minimizing the effects of these compounds are necessary. This study compares six plant DNA extraction protocols based on the CTAB method. The quality and quantity of DNA samples obtained were determined by physical appearance by electrophoresis in agarose gels and spectrophotometry. The results highlight the difficulty in obtaining pure and clear bands for all tested methods, except for the polyvinylpyrrolidone (PVP)-based protocol created by our team, which was the better option for obtaining high-quality genomic DNA of L. alba. We conclude that adding PVP-40 into DNA extraction buffers can optimize the DNA extraction of L. alba and indicate this protocol for DNA extraction from other aromatic plants.

Hardness and Depth of Cure of Conventional and Bulk-Fill Composite Resins in Class II Restorations with Transparent and Metal Matrix Strips.

Objectives: Hardness is relevant to the degree of conversion (DC) and depth of cure (DoC). The aim of this study was to determine the micro-hardness and DoC of conventional and bulk-fill composite resins in class II restorations using metal and clear matrix bands. Materials and Methods: Twelve specimens of each of the two composite resins, i.e., Filtek Z350 XT bulk-fill and Gradia posterior conventional composite, were prepared in the form of a class II cavity in a tooth mold, using a clear or metal matrix band. All specimens were cured and stored at 37°C for 24 hours. Vickers hardness was measured as a function of DoC at 2mm intervals. Data were analyzed by two-way ANOVA (alpha=0.05). Results: The bulk-fill composite exhibited significantly higher hardness levels than the conventional composite in all tested surfaces (P<0.001). However, while the metal matrix band had a significant impact on the bottom surface (P=0.059) and also on the furthest surface from the matrix and light source (P=0.04), it did not have a consistent effect across all tested surfaces. The simultaneous interaction of the composites and matrix band types in all surfaces, did not show significant differences in hardness values. The highest bottom-to-top surface hardness ratio (73%) was observed in the conventional composite near the metal matrix band. Conclusion: In deep class II cavities, the bottom-to-top surface hardness ratio did not reach the maximum of 80%, neither for bulk-fill nor conventional posterior composites. Therefore, in such cavities extended light-curing and more incremental composite placement is needed.

Two-section branch-line hybrid couplers based broadband transmit/receive switch

&lt;p&gt;This article introduces a broadband microstripline-based transmit/receive switch for 7-Tesla magnetic resonance imaging. The designed switch aims to handle a signal of multiple frequencies to/from a multi-tuned radio-frequency coil that resonates at frequencies corresponding to the speed of precession of a wide range of atomic X-nuclei, at the same time and without tuning. These include 1H, 23Na, 13C, 31P, 19F, and 7Li used in magnetic resonance spectroscopy as a measure to the existence of many diseases. The fundamental and third harmonic center frequencies of the switch are adjusted to resonate at two broadbands covering a wide range of atomic X-nuclei. Two section branch-line hybrid couplers with phase inverters are designed to build the broadband switch. The designed switch used the minimum trace widths of transmission lines that reveal a compact size without increasing the heat and then the loss beyond specific values. The couplers and the switch S-parameters exhibited good return loss (&amp;lt;-10 dB), high isolation (&amp;lt;-40 dB), less insertion loss (&amp;lt;1 dB) and two clear wide bands covering many atomic X-nuclei used in diagnosis, at the same time and without the need for any tuning circuit during operation.&lt;/p&gt;

Strong surface winds in Storm Eunice. Part 1: storm overview and indications of sting jet activity from observations and model data

Strong surface winds in Storm <i>Eunice</i>. Part 1: storm overview and indications of sting jet activity from observations and model data

Influence of the grade of hot work tool steels and its microstructural features on the durability of punches used in the closed die precision forging of valve forgings made of nickel-chrome steel

The work concerns research related to the assessment of the influence of the impact of the steel grade used for forging punches in terms of the durability of tools used in the precision forging process in closed dies of a chrome-nickel steel valve forging. The tests were carried out on post-service punches, showed microstructural differences in the intensity of carbide precipitations banging. Two of them were made of a materials showing carbide banding (W360 after ESR; 1.2365), which achieved average durability at the level of: 2400 and 1200 forgings. The other two were without clear carbide banding (Unimax after ESR; 1.2344). They also had much lower durability at the level of: 700 and 200 forgings. Tests of post-service punches were carried out in order to assess the mechanism of their destruction. They were supplemented with hardness measurements. The dominating mechanism of their wear was the loss of properties of the surface layer. The decrease in hardness and plastic deformation of the material resulted in increase of the punches wear rate. As part of laboratory tests, scratch-tests and abrasion wear tests on a “ball on disc” tribotester at elevated temperatures (above 400 °C, i.e. contact temperature: tool-forging) were carried out. The obtained test results showed that punches made of materials with distinct banding, compared to materials with evenly spaced carbide clusters, are characterized by better resistance to the destructive mechanisms prevailing in hot forging processes.

INFRARED SPECTROSCOPIC ANALYSIS OF COMPLEX OXIDE CATALYST 50%Cu3(PO4)2•50%Ni3(PO4)2

It is established that the frequencies and intensities of the absorption bands of the infrared spectra of the obtained air-dried sample 50%Cu3(PO4)2∙50%Ni3(PO4)2 and calcined at the optimum heat treatment temperature of 600оС are characterized by significant absorption in the valence (3460-3020 cm-1) and strain (2360-1400 сm-1) vibrations of hydroxyl OH-groups of water molecules. Valence vibrations of phosphate ion are most manifested in dehydration products in the form of clear bands in the absorption frequency range 1110-410 сm-1. For the investigated sample, three absorption bands were observed in the region: 3188,72 сm-1, 1621,84 сm-1 та 1434,78 сm-1. They confirm the existence of two types of crystalline hydrate water molecules, which are characterized by different hydrogen bonding energies. In the process of heat treatment of the synthesized sample in the temperature range of 120-700оС , the process of dehydration occurs. In this case, the intensity of the absorption bands in the region of valence and strain vibrations of water molecules gradually decreases in the obtained IR spectra. The phenomenon of complication of the spectrum of orthophosphate ion by additional absorption bands is obviously associated with the distortion of the tetrahedron structure in real crystals and the reduction of its symmetry. It can be a consequence of both low symmetry of the environment and perturbation of the orthophosphate anion РО43– by water molecules when intermolecular hydrogen bonds occur. It may also be due to possible additional coordination of orthophosphate anion with metal cations Сu2+ and Ni2+. Calcination of the sample at the final heat treatment temperature of 700оС leads to an anhydrous orthophosphate system. This will lead to a decrease in the value of surface acidity and catalytic inertness of the sample.&#x0D; Keywords: catalysts; heterogeneous catalysis; phosphates; complex oxides; oxidation; n-alkanes; hydrocarbons; ethane; ethylene; IR spectroscopy.

Deciphering the Genetic Identity and Fidelity of Banana Genotype Musa acuminata through Molecular Fingerprinting

Micropropagation for extensive production of elite planting materials is an effective and superior alternative to suckers and conventional means of propagation of Musa spp. The present investigation was carried out to evaluate the genetic identity of different micropropagated banana genotypes Grand Naine, Shrimantee and Basrai. Further micropropagated banana genotypes Grand Naine comparing with mother plant during different stages of subculture using Simple Sequence Repeat (SSR) and Inter Simple Sequence Repeat (ISSR). Moreover, for micropropagation explants (suckers) were inoculated on initiation medium containing MS (Murashige and Skoog) supplemented with 5 mg/l BAP (Benzyl amino purine) and 39 mg/l AdSO4 (Adenine sulphate). The second, third and fourth subcultures were carried out to separate all multiple shoots. Furthermore, for rooting MS media fortified with growth hormones viz., 2 mg/l BAP, 1mg/l IBA (Indole-3-butyric Acid) and 200mg/l activated charcoal were used under present investigation. Findings revealed that 90 % and 75 % plantlets were successfully established during primary hardening in controlled and natural field condition. Further, 26 primers were screened from that 20 primers (ISSR and SSR) showed 146 clear, reproducible and scorable bands ranging from 100-2000 base pairs produced. The banding pattern of these randomly selected plants was monomorphic with mother plant of all selected genotype that confirmed the clonal uniformity.