MAT-715: SUSTAINABLE HIGH-VOLUME FLY ASH GROUTS FOR TWO-STAGE CONCRETE

Two-stage concrete (TSC) is a special type of concrete in which coarse aggregates are pre-placed in the formwork and subsequently injected with a grout. Beneficiating fly ash in TSC grouts increases TSC sustainability through the ecological use of large quantities of fly ash, reduced carbon-dioxide emissions associated with cement production, and enhancement of resource productivity of the concrete industry. Limited research has explored the effects of using high volume of fly ash as partial replacement for cement in TSC grout mixtures. Therefore, the flowability of grout mixtures incorporating various fly ash addition rates (i.e. 0%, 30%, 50% and 70%) was evaluated using the flow cone method and spread flow test. Correlations between the efflux time and spread flow for the grout mixtures were developed. Results show that increasing the fly ash addition reduced the grouts efflux time while increasing its spread flow. The optimum high-volume fly ash dosage for achieving high flowability and acceptable TSC compressive strength was identified

Identifying Difficult exercises in an eTextbook Using Item Response Theory and Logged Data Analysis

The growing dependence on eTextbooks and Massive Open Online Courses (MOOCs) has led to an increase in the amount of students' learning data. By carefully analyzing this data, educators can identify difficult exercises, and evaluate the quality of the exercises when teaching a particular topic. In this study, an analysis of log data from the semester usage of the OpenDSA eTextbook was offered to identify the most difficult data structure course exercises and to evaluate the quality of the course exercises. Our study is based on analyzing students' responses to the course exercises. We applied item response theory (IRT) analysis and a latent trait mode (LTM) to identify the most difficult exercises .To evaluate the quality of the course exercises we applied IRT theory. Our findings showed that the exercises that related to algorithm analysis topics represented the most difficult exercises, and there existing six exercises were classified as poor exercises which could be improved or need some attention.Comment: 6 pages,5 figure

A Predictive Model for Student Performance in Classrooms using Student Interactions with an eTextbook

With the rise of online eTextbooks and Massive Open Online Courses (MOOCs), a huge amount of data has been collected related to students’ learning. With the careful analysis of this data, educators can gain useful insights into their students’ performance and their behavior in learning a particular topic. This paper proposes a new model for predicting student performance based on an analysis of how students interact with an interactive online eTextbook. By being able to predict students’ performance early in the course, educators can easily identify students at risk and provide a suitable intervention. We considered two main issues: the prediction of good/bad performance and the prediction of the final exam grade. To build the proposed model, we evaluated the most popular classification and regression algorithms. Random Forest Regression and Multiple Linear Regression have been applied in Regression. While Logistic Regression, decision tree, Random Forest Classifier, K Nearest Neighbors, and Support Vector Machine have been applied in classification. Based on the findings of the experiments, the algorithm with the best result overall in classification was Random Forest Classifier with an accuracy equal to 91.7%, while in the regression it was Random Forest Regression with an R2 equal to 0.977

Feasibility of Artificial Insemination Network for Egyptian Buffalo Development

Literature reviews confirmed that Egypt has a comparative advantage in milk production rather than red meat production, particularly from buffalo. Furthermore, water resources are becoming increasingly scarce, limiting horizontal expansion in fodder acreage. Furthermore, there is fierce competition between food and feed demand on available agricultural land resources. As a result, horizontal expansion in dairy buffalo stock would be impossible. As a result, the only option for buffalo development in Egypt is vertical expansion through increased milk yield to meet the current deficit in domestic milk production. The Egyptian consumer prefers buffalo milk for its color taste and high content of total solids, particularly fat. Buffalo milk is more expensive than cow milk, and its production is increasing faster than cow milk production. The proposed genetic improvement of buffalo milk yield is being accelerated using an artificial insemination (AI) network. A recent study [1], provided evidence that the return of genetic investment in dairy buffalo would be feasible, (IRR = 19.71%) However, according to official statistics, Egypt has only two AI-centers for buffalo selected buffalo sires, serving four AI-units. As a result, the goal of this study was to assess the feasibility of establishing an AI-network in Egypt by estimating (NPV, IRR, and payback period) and its sensitivity to unfavorable changes that the proposed program may face. The study used a field survey data collected from an AI-unit of the buffaloes’ semen and an AI-Center for raising buffalo sires in Nile Delta. The findings showed that, while the Egyptian economy's average discount rate was 17.5 %, the estimated IRR for one AI-unit was around 35 % under the most likely scenario. A 10% decrease in semen price and a 10% increase in insemination costs would result in IRRs of approximately 28% and 31%, respectively. Under the most likely conditions, the estimated IRR for the AI-center was around 31%. 10% Decrease in Semen Price, and 10% increase in feed costs or in Sire’s price would result in 26%, 30% or 28% respectively. The lowest sale price of semen dose is thus the most effective variable on the IRR. Unfavorable changes, on the other hand, would keep investments with high incentives in establishing a feasible AI-Network for rapidly increasing the dairy buffalo milk yield

MAT-716: GREEN SIDEWALKS USING SUSTAINABLE TWO-STAGE CONCRETE

Two-stage concrete (TSC) is a special type of concrete, which has a high potential for use in sidewalk construction owing to its high volume stability. TSC is characterized by its high coarse aggregate content. Hence, using recycled solid waste materials as a coarse aggregate will increase TSC sustainability, while providing a cost-effective alternative to natural aggregates. Aggregates are pre-placed in TSC. Hence, water absorption by recycled concrete aggregates and the associated rheology problems do not exist in TSC. This study explores the performance of green TSC sidewalks incorporating recycled concrete aggregates (RCA) and crumb rubber from scrap tires. Mechanical properties of the proposed green TSC including compressive strength, modulus of elasticity, flexural strength and toughness, as well as durability to freeze-thaw cycles were investigated. Results show a slight reduction in TSC mechanical properties due to the use of RCA. Moreover, incorporating tire particles reduced TSC mechanical properties significantly, while improving its toughness and freeze-thaw resistance. Addition of recycled tire steel wires allowed to overcome the negative effects on the mechanical properties induced by crumb tire rubber. Therefore, recycling solid waste materials in TSC sidewalks can be an effective strategy to beneficiate such waste materials

Bio-stimulants as alternatives to mineral fertilizers: influence on chia (Salvia hispanica L.) growth, yield, and fatty acid composition

One of the main components of sustainable agricultural strategies in crop production is substitution of chemical fertilizers with alternatives. This study aimed to examine the effects of partial replacement of mineral fertilizers with bio-stimulants (yeast and/or moringa leaves extract). Field experiment was conducted during two successive seasons 2018/2019 and 2019/2020. The fertilization treatments were distributed in a factorial design. Treatments included 75%, 50% or 0% NPK combined with yeast, moringa extract, or their combination in comparison with control treatment (100% NPK). The partial substitution of mineral fertilizers with yeast and/or moringa extract had significant impacts on growth, yield and quality components. Decreasing NPK level significant decreased growth and yield components of chia plants, except for 75% NPK combined with yeast and/or moringa. In contrast, decreasing NPK level significantly increased the chemical and quality components of chia. Treating with 75% NPK combined with yeast and/or moringa gave the highest micronutrients and fatty acid content. GC analysis showed definition of nine main components, and the major components were linolenic and linoleic acids. Linolenic acid increased with decreasing NPK, and the highest values obtained with bio-stimulant treatments with zero % NPK. The results of this study recommended that partial substitution of 25% of mineral fertilizers with bio-stimulants (yeast and/or moringa) is the best alternative not only for maintaining the growth and yield component, but also improving the quality of chia plants

Antioxidant and hepatoprotective effects of Astragalus echinops and Astragalus logopodioides ethanolic extracts on paracetamol-induced liver injury in rats

Background: Paracetamol (PCM) has an adequate safety profile when taken in normal doses. However, it could produce oxidative stress with liver injury when taken in an overdose. Plants of Astragalus genus (F. Fabaceae) are of wide-spread applications. Astragalus echinops (A. echinops) and Astragalus logopodioides (A. logopodioides) were tested for their potential hepatoprotective activities against liver injury induced by PCM in rats.Material and Methods: Seven groups of rats were used for determination of hepatoprotective activities of the extracts. The normal and hepatotoxic control groups received the vehicle while other groups were treated with silymarin (100 mg/ kg), A. echinops (250 and 500 mg/kg) and A. logopodioides (250 and 500 mg/ kg), respectively for seven days. Liver injury was induced on the 5th day by oral dosing of PCM (2g/kg) to all rats except those in normal control group. Moreover, the in vitro antioxidant activities of A. echinops and A. logopodioides extracts were tested using 2,2- diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging.Results: Hepatic enzyme markers as alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and glutamyl transferase and level of total bilirubin were significantly elevated, while total protein and albumin were declined significantly in PCM-exposed animals. The liver antioxidant markers like the activities of superoxide dismutase, catalase and glutathione peroxidase and the levels of reduced glutathione were significantly declined, while hepatic malondialdehyde levels were significantly increased in PCM alone-treated rats. Administration of A. echinops (250 and 500 mg/kg) and A. logopodioides (500 mg/ kg) extracts prior to PCM, significantly protected against the elevation in the serum activities of hepatic enzymes and bilirubin and reduced oxidative stress. The hepatoprotective effect of both extracts was further confirmed by histological findings in the liver tissue. In addition, both extracts displayed in vitro antioxidant activities in a concentration-dependent way.Conclusion: Our results suggest that both extracts protect the liver against oxidative damage and they could be used as effective hepatoprotectives against PCM induced liver injury.Keywords: Astragalus, Paracetamol, Hepatotoxicity, Hepatoprotective, DPPH, Antioxidan

Genetic diversity assessment and in vitro propagation of some date palm (Phoenix dactylifera L.) varieties

The evaluation of genetic diversity is crucial for breeders to develop strategies and improve the resilience, quality, and adaptability of the date palm. In this study, the genetic diversity of three date palm varieties was performed using ISSR-PCR molecular markers to determine its relationship with in vitro propagation response of these varieties. The molecular profiling was performed using ISSR-PCR. A total of 49 loci were produced by the PCR reactions, 38 of which were polymorphic while 11 were monomorphic. The level of polymorphism revealed by ISSR-PCR varied from 33.33% to 100%. The three date palm varieties were grouped into two clusters based on the results of cluster analyses that used morphological data and molecular profiles. Cluster I comprised the ‘Barhy’ variety and Cluster II included ‘Magdoul’ and ‘Amri’ varieties. The clustering analyses revealed the independence of the ‘Barhy’ variety in its characteristics from the other varieties based on either morphological or molecular data. The results of in vitro propagation showed that the ‘Amri’ variety exhibited the highest callus induction frequency (86.28%), callus weight (2.33 g), number of somatic embryos (9.32), number of shoots (14.62), number of roots (4.11), root length (4.63 cm), shoot length (13.61 cm) followed by ‘Magdoul’ and ‘Barhy’ varieties. The ‘Amri’ variety had the shortest callus induction period, at 23.26 days while the ‘Barhy’ variety exhibited the longest period of callus induction (28.55). It was deduced from the study that the ISSR marker reproduced trustworthy patterns of bands to determine the genetic diversity among different date palm varieties that are considered the cornerstone for the genetic improvement of date palms. The understanding of the relationship between genetic diversity and in vitro propagation response of date palm is essential for ensuring the long-term sustainability of its crop. This will facilitate better conservation and development of new date palm varieties that fulfil the needs of farmers and consumers

ANTIOXIDANT AND HEPATOPROTECTIVE EFFECTS OF ASTRAGALUS ECHINOPS AND ASTRAGALUS LOGOPODIOIDES ETHANOLIC EXTRACTS ON PARACETAMOL-INDUCED LIVER INJURY IN RATS

Background: Paracetamol (PCM) has an adequate safety profile when taken in normal doses. However, it could produce oxidative stress with liver injury when taken in an overdose. Plants of Astragalus genus (F. Fabaceae) are of wide-spread applications. Astragalus echinops (A. echinops) and Astragalus logopodioides (A. logopodioides) were tested for their potential hepatoprotective activities against liver injury induced by PCM in rats. Material and Methods: Seven groups of rats were used for determination of hepatoprotective activities of the extracts. The normal and hepatotoxic control groups received the vehicle while other groups were treated with silymarin (100 mg/ kg), A. echinops (250 and 500 mg/kg) and A. logopodioides (250 and 500 mg/ kg), respectively for seven days. Liver injury was induced on the 5th day by oral dosing of PCM (2g/kg) to all rats except those in normal control group. Moreover, the in vitro antioxidant activities of A. echinops and A. logopodioides extracts were tested using 2,2- diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging. Results: Hepatic enzyme markers as alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and glutamyl transferase and level of total bilirubin were significantly elevated, while total protein and albumin were declined significantly in PCM-exposed animals. The liver antioxidant markers like the activities of superoxide dismutase, catalase and glutathione peroxidase and the levels of reduced glutathione were significantly declined, while hepatic malondialdehyde levels were significantly increased in PCM alone-treated rats. Administration of A. echinops (250 and 500 mg/kg) and A. logopodioides (500 mg/ kg) extracts prior to PCM, significantly protected against the elevation in the serum activities of hepatic enzymes and bilirubin and reduced oxidative stress. The hepatoprotective effect of both extracts was further confirmed by histological findings in the liver tissue. In addition, both extracts displayed in vitro antioxidant activities in a concentration-dependent way. Conclusion: Our results suggest that both extracts protect the liver against oxidative damage and they could be used as effective hepatoprotectives against PCM induced liver injury