Nature and Disposition of the Garnet-Biotite Boundary at Balquhidder, Perthshire, Scotland

The metamorphic rocks at Balquhidder are polyphase deformed and polymetamorphosed with the D1 - D4 sequential development of structures and the M1 - M4 development of minerals generally corresponding to that expressed in nearby areas. Garnet is found throughout the area and the Barrovian garnet-isograd must have been at least 2Km above the present topography. There is no garnet-biotite boundary present. The incoming of garnet was controlled by the bulk rock composition so that garnetiferous and non-garnetiferous schists can occur in the same, or adjacent outcrops. Textural studies have shown that two phases of garnet growth occurred. The more prominent of these was during M2 when three different types were formed (G2A, G2B, G2C), two only lithologies of the Pitlochry Schist (G2A, G2C) and the other (G2B) only in the Ben Lui Schist. Growth of garnet was related to particular mineral reactions, non-instantaneous nucleation and reaction partitioning. This has been substantiated by the determination, using the electron microprobe of chlorite, muscovite, garnet, biotite, albite and hornblende compositions. Garnet-biotite and garnet-hornblende pairs permit temperatures of M2 metamorphism to be determined: 530 C - 482 C for type G2A (almandine), 423 - 410 C for type G2B (almandine) and 370 C for type G2C (spessartine-rich). The 530 C estimate for G2A is considered to represent climactic conditions and, when considered with a pressure estimate of 7Kb based on the biotite-muscovite-chlorite-quartz geobarometer, indicates a typical Barrovian heat flow of c. 27 C/Km and mid-amphibolite-facies conditions. On the basis of regional correlation of structures, the M2 metamorphism (and D1 - D2) is related to the pre-590Ma Grampian Orogeny and was followed by elevation of temperature to its peak during crustal thickening during D1 (Tay Nappe formation). A second phase of garnet growth took place post-D2 - pre-D4 (possibly post-D2 - pre-D3). Temperature of development of G2-4 (?G2-3) was 377 C for a spessartine-rich type, i. e. in the green schist facies. The elevation of temperature is related to the c. 500Ma event demonstrated elsewhere in the Highlands on the basis of isotopic studies and during which crustal thickening is postulated. Previous interpretations of the presence of an inverted garnet isograd are not substantiated by this investigation. The structural development does not permit inversion of M2 or M2-4 geotherms by tectonic activity, while the distribution of garnet throughout the area does not permit the presence of any isograd to be demonstrated. Rather the whole area is within the garnet zone. Two of the previous interpretations, which suggest an inverted zonal distribution, recognized neither the composition - nucleation - reaction partitioning controls nor the polyphase development of garnet. One sets out a position for a "garnet isograd" that corresponds to the prominent development of G2A and G2C garnets in particular flat-lying units of the Pitlochry Schist. The other sets out a position for a "garnet isograd" that corresponds to the prominent development of G2B and G2-4 garnets in particular units of the Ben Lui Schist. These interpretations are rejected on the basis of the detailed evidence set out here. D4 and post-D4 mineralogical expressions only result in minor modifications to the earlier formed features. D4 is correlated with the regionally expressed c. 460Ma period of uplift and post-D4 mineral growth was both prograde and retrograde. The deformation and metamorphic history in the Balquhidder area generally corresponds to, and may be representative of, Caledonian activity in at least considerable parts of the SW Highlands

Biochemical composition and antioxidant properties of some seaweeds from Red Sea coast, Egypt

The current study investigated the biochemical composition and antioxidant properties of four seaweeds: Laurencia sp. (Rhodophyta), Cystoseira myrica, Hydroclathrus clathratus and Padina pavonica (Ochrophyta). The highest amount of carbohydrates was (215.78 mg/g dry wt.) in Laurencia sp. and proteins content was maximum (50 mg/g dry wt.) in Laurencia sp. and Cystoseira myrica. The highest values of free amino acid content were recorded in the brown seaweed species Cystoseira myrica (4.01 mg/g dry wt.). The pressurized hot water extract of Cystoseira myrica has the highest total phenolic content (1.61 mg GAE/g dry wt.). Cystoseira myrica contained the highest amounts of flavonoids (3.35 mg/g dry wt.), ascorbic acid (9.07 mg/g dry wt.) and α-tocopherol (27.25±0.00 abs. at 520 nm/g dry wt.). Furthermore, the ethyl alcohol extract of Cystoseira myrica showed high antioxidant capacities (541.6 mg/g dry wt.) and achieved the most powerful reducing ability among all of the different extracts of algal species. Statistical evaluation by Spearman correlation between the TAC assay and the total phenolic contents was found to be significant, but the correlation was nonsignificant between FRAP assay and the total phenolic contents. The composition of elements of the studied seaweed species was also analyzed. The most significant macro-elements present in the studied seaweeds were K, Na and Ca, representing that the seaweeds are good sources of these elements. Since, these seaweeds are widespread in the Egyptian waters, their biochemical composition and antioxidant capacities made them promising candidates for industrial, nutritional and pharmaceutical applications. DOI: http://dx.doi.org/10.5281/zenodo.147886

A SHALLOW NEURAL NETWORK MODEL FOR URBAN LAND COVER CLASSIFICATION USING VHR SATELLITE IMAGE FEATURES

Recently, image classification techniques using neural networks have received considerable attention in sustainable urban development, since their applications have an extreme effect on building distribution, infrastructural networks, and water resource management. In this research, a back-propagation shallow neural network model is presented for very high resolution satellite image classification in urban environments. Workflow procedures consider selecting and collecting data, preparing required study areas, extracting distinctive features, and applying the classification process. Visual interpretation is performed to identify observed land cover classes and detect distinctive features in the urban environment. Pre-processing techniques are implemented to present the used images in a more suited form for the classification techniques. A shallow neural network model (supported by MathWorks MATLAB environment) is successfully applied and results are evaluated. The proposed model is tested for classifying both WorldView-2 and WorldView-3 multispectral images with different spatial and spectral characteristics to check the model’s applicability to various kinds of satellite imagery and different study areas. Model outcomes are compared to two well-known classification methods; the Nearest Neighbour object-based method and the Maximum Likelihood pixel-based classifier, to validate and check the model stability. The overall accuracy achieved by the proposed model is 86.25% and 83.25%, while the nearest neighbour approach has obtained 84.50% and 82.75%, and the maximum likelihood classifier has accomplished 82.50% and 80.25% for study area 1 and study area 2 respectively. Obtained results indicate that the developed shallow neural network model achieves a promising accuracy for urban land cover classification in comparison with the standard techniques

Vibration Signature of Roller Bearing’s Faults

Centrifugal pumps are widely used in many industrial applications. Defective pumps cause higher rate of energy loss with related overall performance degradation. Mechanical components fail due to decrease in pump’s strength or an increase in the force acting on it. Rolling bearings are one of the major components of the centrifugal pumps. Bearings are critical mechanical components in industrial machines. Bearing failure is often attributed to be one of the major causes of breakdown. Early detection of undesired conditions during the operation of the centrifugal pump has become very important in order to avoid consequential damages. Early detection is also vital for increasing availability and reliability. Automated health monitoring can reduce the outage time and repair costs. Using vibration analysis technique to monitor and evaluate the health of the machines has become an important technique in this field. In this research, we studied the vibration signatures of healthy and faulty conditions of the bearings of a pumping system. The pumping system consists of centrifugal pump and electrical motor. The vibration signatures analyze the bearing status with respect to the normal operation. The paper shows how to identify if there is a problem in the outer race of the Bearing Pass Frequency Outer Race (BPFO)

Ion beam and discharge characteristics of cold cathode ion source

24-30In this work, some developments in the acceleration system of cold cathode ion source have been constructed to produce broad beam to be used in different industrial applications. An electrostatic probe with electrical circuit is constructed for study the extracted ion beam distribution. Broad beam 25 mm with ion current in the range of 1 mA is extracted from the constructed extraction system. The obtained optimum distance between the extraction grid and acceleration grid is 3 mm. The characteristics are measured to investigate the ion beam current Ib as a function of different parameters (discharge voltage Vd, gas pressure P, magnetic field intensity B and acceleration voltage Vacc). The magnetic field is collimated and intensifies the plasma that enhances the extracted beam current. The obtained cold cathode ion source can be used in different applications like surface etching, surface modification and deposition due to its long life and compactness

Diagnostic performance of alpha-fetoprotein, YKL40 and GP73 in hepatocellular carcinoma Egyptian patients

Background: Hepatocellular carcinoma (HCC) is a primary malignancy of the liver. It is responsible for a large proportion of cancer deaths worldwide. Diagnosis of HCC often requires more sophisticated modalities and represents a challenge for physician.  Methods: This study aimed to compare the diagnostic performance of AFP, YKL40 and GP73 in patients' serum with hepatocellular carcinoma (HCC) in high-risk population in an attempt to justify the new, sensitive, specific and rapid measure for the diagnosis and detection of HCC. Serum YKL40, GP73 and alpha-fetoprotein (AFP) were compared in a total of 60 human subjects in this study, including 20 healthy adults, and 40 patients with HCC, The main outcome measures were the specificity and sensitivity of YKL40 and GP73 in patients at risk for the development of HCC.Results: Using 4.4 relative units as a cut-off value, the sensitivity and specificity of serum GP73 for HCC were 85% and 90% compared with 77% and 60% for YKL40 using 21.06 ng/ml as a cut-off value. On the same context, the sensitivity and specificity of serum AFP at 8.5ng/ml cut-off were 82% and 95%. While that for the AFP and GP73 combined detection was up to 92% and 96%, justifying that the combined detection could prevent the false negative diagnosis by any marker alone and significantly improve the detection rate of HCC.Conclusions: The current evidence indicates that serum GP73 has HCC diagnostic efficacy inferior to that of AFP and YKL40 and the clinical implementation of serum GP73 measurement as a standard test for HCC is recommended alone or in combination with AFP.

Presence of Human Herpes Virus 6 (HHV6) in pediatric lymphomas: impact on clinical course and association with cytomegalovirus infection

<p>Abstract</p> <p>Background</p> <p>Activation of herpes virus 6 (HHV6) has seen in Hodgkin's and non-Hodgkin's Lymphoma (HL&NHL) as a result of lymphoma associated immunosuppression. Multiple studies have suggested an association between both HHV6 and cytomegalovirus CMV for development of CMV disease affecting the pathogenesis of lymphoma. Therefore, this study investigated the frequency of HHV6, its impact on clinical manifestations of lymphoma and its possible association with risk for development of CMV infection in pediatric lymphoma patients.</p> <p>Methods</p> <p>Presence of HHV6 DNA and CMV DNA was investigated by PCR assay in both WBC's and plasma samples from 50 patients diagnosed with HL or NHL. CMV antibody titer was also determined in sera obtained from each patient. Twenty apparently healthy siblings were used as a control group.</p> <p>Results</p> <p>In a study group of 50 patients diagnosed with HL or NHL, 23/50 (46%) were found to be positive for herpes virus DNA (HHV6 or CMV) in WBC's or plasma by PCR assay and this was significantly higher than its presence in the pediatric control group 2/20 (10%) (p = 0.005). Ten out of these 23 (43%) were found to have active CMV infection. Fifty six percent of patients with CMV infection were found among NHL cases with B- subtype. The presence of both herpes viruses DNA was significantly associated with more frequent episodes of febrile neutropenia (median 3 episodes), absolute neutrophil count (< 0.8), lymphocytes (< 0.5), and low hemoglobin level (< 9.1), (p < 0.05).</p> <p>Conclusion</p> <p>The presence of HHV6 can be considered as a predicting indicator of cellular immunosuppression preceding the onset of CMV infection which may result in a severe outcome among pediatric lymphoma patients.</p

Enhancing the Performance of Power System under Abnormal Conditions Using Three Different FACTS Devices

In this paper, a comparison between Flexible Alternating Current Transmission System (FACTS) devices including Static Synchronous Compensator (STATCOM), Static Synchronous Series Compensator (SSSC) and Unified Power Flow Controller (UPFC) for providing a better adaptation to changing operating conditions and improving the usage of current systems. The power system using FACTS devices is presented under different conditions such as single phase fault and three phase fault. A digital simulation using Matlab/Simulink software package is carried out to demonstrate the better performance including the voltage and the current of the presented system using FACTS that located between buses B1 and B2 under different faults types. The results obtained investigate that the presented system gives better response with FACTS as compared to not using them under abnormal conditions besides, the UPFC gives better performance of power system under several faults as compared to STATCOM or SSSC as It can absorb reactive power in a manner which significantly reduced the fault current. It is demonstrated that UPFC can reduce the peak fault current at bus B1 ‎to 63.85% of its value without ‎using FACTS devices under line to ground fault and 79.18% under three line to ‎ground fault whereas STATCOM and SSSC reduce it ‎to (75.21, 94.35%) and (75.40, 94.68%), respectively

Ion beam and discharge characteristics of cold cathode ion source

In this work, some developments in the acceleration system of cold cathode ion source have been constructed to produce broad beam to be used in different industrial applications. An electrostatic probe with electrical circuit is constructed for study the extracted ion beam distribution. Broad beam 25 mm with ion current in the range of 1 mA is extracted from the constructed extraction system. The obtained optimum distance between the extraction grid and acceleration grid is 3 mm. The characteristics are measured to investigate the ion beam current Ib as a function of different parameters (discharge voltage Vd, gas pressure P, magnetic field intensity B and acceleration voltage Vacc). The magnetic field is collimated and intensifies the plasma that enhances the extracted beam current. The obtained cold cathode ion source can be used in different applications like surface etching, surface modification and deposition due to its long life and compactness