Characteristics of Portland Cement Pastes Blended with Silica Nanoparticles

The effect of silica nanoparticles (SNP) addtion on the specific characteristics of Portland cement pastes was investigated. The results revealed that the addition of SNP to the fresh Portland cement pastes reduced both w/c ratio and setting times, but increased significantly the early age strength development. The presence of the water-reducing admixture (Na-lignosulphonate) further improved the wokability and performance of cement pastes.The replacing of SNP up to 1.5 wt. % at the expense of cemen improved and enhanced the combined water content, bulk density, total porosity and compressive strength at all curing ages of hydration. The cement mix incorporated 1.5 wt. % (Sn3) is considered to be the optimum cement patch, where it exhibited the best results and were becoming better and higher than those of the pure cement (Sn0) at all curing stages of hydration. With the addition of more than 1.5 wt. % SNP to the cement (Sn4 and Sn5), all cement properties were adversely affected. Therefore, the higher additions of NSP must be avoided

Critical Study on the Concept of International Arbitration in the UAE: Identifying Problems Affecting the Recognition and Enforcement of Foreign Arbitral Award

This thesis intends to critically explore the legal obstacles currently undermining the recognition and enforcement process of foreign and international arbitral awards in the UAE arising out of the lack of the concept of international arbitration. it also tackles the practical implications caused by the lack of separate arbitration legislation and various legal aspects

Comparison of two methods of noise power spectrum determinations of medical radiography systems

Noise in medical images is recognized as an important factor that determines the image quality. Image noise is characterized by noise power spectrum (NPS). We compared two methods of NPS determination namely the methods of Wagner and Dobbins on Lanex Regular TMG screen-film system and Hologic Lorad Selenia full field digital mammography system, with the aim of choosing the better method to use. The methods differ in terms of various parametric choices and algorithm implementations. These parameters include the low pass filtering, low frequency filtering, windowing, smoothing, aperture correction, overlapping of region of interest (ROI), length of fast Fourier transform, ROI size, method of ROI normalization, and slice selection of the NPS. Overall, the two methods agreed to the practical value of noise power spectrum between 10 -3-10-6mm2 over spatial frequency range 0-10mm-1

Techno-Economics of Hybrid NF/FO with Thermal Desalination Plants

Hybrid desalination technology is defined as any combination of thermal and membrane processes in seawater desalination systems. So far, the two technologies have evolved rather independently with some degree of competition. Traditionally, in co-generation market applications, thermal desalination has succeeded in establishing a stronghold where large capacities are needed, energy costs are low, and seawater quality is challenging. However, in recent years, membrane systems have also succeeded in grabbing a larger share of the world seawater desalination market, mainly as a result of progress made in membrane and energy recovery technologies. Realizing the potential benefits and challenges faced by both technologies on their own, designers have been looking for ways to synergize and combine the two technologies in optimum configurations, which promise to further reduce the total cost of seawater desalination

Cross-lingual Emotion Detection

Emotion detection is of great importance for understanding humans. Constructing annotated datasets to train automated models can be expensive. We explore the efficacy of cross-lingual approaches that would use data from a source language to build models for emotion detection in a target language. We compare three approaches, namely: i) using inherently multilingual models; ii) translating training data into the target language; and iii) using an automatically tagged parallel corpus. In our study, we consider English as the source language with Arabic and Spanish as target languages. We study the effectiveness of different classification models such as BERT and SVMs trained with different features. Our BERT-based monolingual models that are trained on target language data surpass state-of-the-art (SOTA) by 4% and 5% absolute Jaccard score for Arabic and Spanish respectively. Next, we show that using cross-lingual approaches with English data alone, we can achieve more than 90% and 80% relative effectiveness of the Arabic and Spanish BERT models respectively. Lastly, we use LIME to interpret the differences between models

Palm Ash as a Pozzolanic Material for Portland Cement Pastes

The effect of the substitution of palm ash (PA) on the physico-chemical and mechanical properties of Portland cement pastes (OPC) was clearly evaluated. Results showed that as the PA content increased, the fineness as well as the heat of hydration of the whole mix increased too.  The water of consistency (WC) and set times (ST) decreased with the increase of PA content due to the presence of the water reducing admixture. The bound water content (BWn), bulk density (BD) and compressive strength (CS) improved and enhanced up to 20 % PA content, and then decreased onward at all hydration periods, while the total porosity decreased and then increased. Above 20 % PA content, all properties were adversely affected. The free lime content (FLn) of the OPC increased continuously up to 90 days, but decreased with PA content. The FTIR spectra illustrated that there is a large amount of free lime content with P0 (OPC), but it gradually decreased with PA content. The SEM microscopy demonstrated the formation of ettringite phase and aggregates of CSH in addition to free lime. In the case of PA blended cement pastes the ettringite was disappeared completely and well-defined crystals were detecte

Cogeneration Power-Desalting Plants Using Gas Turbine Combined Cycle

The gas-steam turbine combined cycle (GTCC) is the preferred power plant type because of its high efficiency and its use of cheap and clean natural gas as fuel. It is also the preferred type in the Arab Gulf countries where it is used as cogeneration power-desalting plant (CPDP). In this chapter, descriptions and analysis of the GTCC components are presented, namely, the gas turbine cycle (compressor, combustor, gas turbine), heat recovery steam generator, and steam turbine. Combinations of the GTCC with thermally driven desalination units to present CPDP are presented. A parametric study to show the effect of using GTCC on several operating parameters on the CPDP is also presented, as well as cost allocation methods of fuel between the two product utilities (electric power and desalted seawater are also presented)

Polymorphism of growth hormone gene and its association with wool traits in Egyptian sheep breeds

Growth hormone (GH) gene has been described as a candidate gene for marker-assisted selection in different farm animals. The present study was designed to identify the polymorphism in GH gene and its association with variation of wool traits in Egyptian sheep breeds. Wool and blood samples were collected from 42 animals including two breeds (Barki and Rahmani) and one crossbred (Rahmani x Awase). Measurements of wool traits were analyzed and involved staple strength (Str), staple length (STL), fiber diameter (FD) and clean fleece yield (CFW). DNA was extracted from blood samples and a 365-bp fragment from exon V was amplified by polymerase chain reaction (PCR). Single strand conformation polymorphisim (SSCP) analysis showed two conformational patterns. The pattern I was recorded to be more frequent (83.3, 92.86 and 90%) than pattern II (16.7, 7.14 and 10%) in Barki, Rahmani and crossbred, respectively. The sequence analysis showed one single nucleotide polymorphism (C/T). The pattern I (allele T) has been found to affect CFW and FD than pattern II (allele C). Whereas, C allele was more pronounced for Str and STL. These traits are the most important parameters determining commercial values of wool that are preferred for clothing or carpets industry. The nucleotide sequences of C and T alleles were submitted to GenBank and have the accession numbers: KT250511 and KT250512, respectively. In conclusion, the present results provide evidence that there is a single nucleotide polymorphism within GH gene in Egyptian sheep breeds. This mutation was found to have some effects on wool traits. Therefore our data show interesting prospects in future selection programs for improving wool industry.Key words: Sheep, wool, growth hormone (GH) gene, polymorphism, single strand conformation polymorphism (SSCP)