An investigation into solid waste problem in the Egyptian construction industry: A mini-review

Solid waste management (SWM) is one of the most critical global challenges nowadays. It has a severe negative effect on the triple bottom line of sustainability. Construction and demolition waste (CDW) contributes about 50% of the total global annual generated SW. In the particular case of the Middle East and North Africa (MENA) region including Egypt, the SW problem has become a major challenge, and the need to find sustainable solutions is overwhelming. However, the region faces several challenges that hinder the development of an effective and efficient SWM system. This has resulted in the predominance of unsustainable SWM practices such as indiscriminate disposals. The aim of this paper is to investigate the escalating problem of SW in the MENA region, while focusing on CDW in Egypt as a part of the total generated SW, by reviewing the most recent research papers, and technical and governmental reports on the SW problem. The main challenges towards effective and efficient SWM systems and recommendations for improvement are gathered in this study based on the explored literature. Findings from this study are expected to be beneficial to local and central governments, academics, construction industry practitioners, and policymakers contending with the problems of SW in the MENA region and especially CDW in Egypt

Adsorptive removal of Fe(III) using gallic acid anchored iron magnetic nano-adsorbents synthesized via two different routes under microwave irradiation

9-20Under microwave solvent free conditions, bare iron magnetic nanoparticles (Fe3O4-MNPs) have been silica coated, amine functionalized and gallic acid grafted, in presence and absence of tetraethylorthosilicate (TEOS). The synthesized adsorbents in both cases have been followed up by Fourier transform infrared, scan electron microscopy and transmission electron microscopy analyses to verify and compare the progress of surface modification. The effects of various parameters on the adsorption efficiency of Fe(III) such as pH of solution, amount of adsorbent and contact time have been studied and optimized. The adsorbents Fe3O4-MNPs-SiO2-CPTMS-1,2-EDA-GA and MNPs-CPTMS-1,2-EDA-GA exhibit higher Fe(III) capacities (4.980 and 4.700 mmol/g) than their analogous Fe3O4-MNPs-SiO2-APTMS-GA and Fe3O4-MNPs-APTMS-GA (4.324 and 4.230 mmol/g). The studies of sorption kinetics showed rapid sorption dynamics by a second-order kinetic model, suggesting chemisorption mechanism. Fe(III) adsorption equilibrium data have been fitted well to the Langmuir isotherm. The results of medium stability as criteria for potential coating and values of metal uptake capacity support the possibility of the direct use of alkoxysilanes as an alternative to TEOS not only for coating but also for amine functionalization. This is strengthened by almost equal capability of gallic acid anchored adsorbents for extraction of trace concentrations of Fe(III) spiked natural water samples

Experimental Study of Power Increase Transient in Heat Generation Systems Simulated By Immersed Heat Source

Theoretical and experimental investigations of the transient heat transfer parameters of constant heat flux source subjected to water flowing in the downward direction in closed channel are conducted. The power increase transient is ensured by step change increase in the heat source power. The theoretical investigation involved a mathematical modeling for axially symmetric, simultaneously developing laminar water flow in a vertical annulus. The mathematical model is based on one dimensional downward flow. The boundary conditions of the studied case are based on adiabatic outer wall, while the inner wall is subjected to a constant heat flux. The heat & mass balance equation derived for specified element of bulk water within the annulus and solved by using Laplace method to determine the variation of bulk water temperature. The experimental investigation included a set of experiments carried out to investigate the temperature variation along the heat source for power increase transient of (5%, 10%, 15% and 20%) of its nominal value during and after reaching the steady state condition. Estimation of the boiling safety factor is predicted and compared with the theoretical values. Reliable agreement between experimental and theoretical approaches is reached. The later showed that the elapsed time required for the clad surface temperature to reach its steady state values after each transient is less than that related to bulk water temperature. New correlation for prediction of critical heat flux, CHF based on inlet water temperature and water mass flux are investigated and compared with CHF correlations obtained from previous researches. Specific recommendations concerned with preventive measured required to eliminate the effect of boiling crisis are concluded based on theoretical and experimental results related to transients setting times obtained from each case study

Adsorptive removal of Fe(III) using gallic acid anchored iron magnetic nano-adsorbents synthesized via two different routes under microwave irradiation

Under microwave solvent free conditions, bare iron magnetic nanoparticles (Fe3O4-MNPs) were silica coated, amine functionalized and gallic acid grafted, in presence and absence of tetraethylorthosilicate (TEOS).  The synthesized adsorbents in both cases were followed up by Fourier transform infrared (FT-IR), scan electron microscopy (SEM) and transmission electron microscopy (TEM) analyses to verify and compare the progress of surface modification.  The results of medium stability as criteria for potential coating and values of metal uptake capacity support the possibility of the direct use of alkoxysilanes as alternative to TEOS not only for coating but also for amine functionalization.  This is strengthened by almost equal capability of gallic acid anchored adsorbents for extraction of trace concentrations of Fe(III) spiked natural water samples

Use of radiographic and histologic scores to evaluate cats with idiopathic megacolon grouped based on the duration of their clinical signs

Since the duration of clinical signs could be used to identify cases of chronic constipation, in addition, prolonged duration is often associated with irreversible changes. Thus, the main objective of this study was to determine whether the duration of clinical signs of idiopathic megacolon in cats affected their diagnosis and prognosis after treatment. Medical records of cats that either had confirmed megacolon for an unknown cause (cat patients) or with normal bowels (control cats) were reviewed. Cat patients were grouped based on the duration of their clinical signs (constipation/obstipation) to cats <6 months and ≥6 months. For all feline patients, abdominal radiographs (for colonic indexes) and resected colon specimens (for histology) were assessed vs. control cats. Treatment applied to cat patients was also evaluated. Cat patients were older (p = 0.0138) and had a higher maximum colon diameter (MCD; mean 41.25 vs. 21.67 mm, p < 0.0001) and MCD/L5L ratio (1.77 vs. 0.98, p < 0.0001) than controls. Compared to cats with <6 months, cats ≥6 months showed a higher MCD (43.78 vs. 37.12 mm, p < 0.0001) and MCD/L5L ratio (1.98 vs. 1.67, p < 0.0001). Histologically, increased thickness of the smooth muscularis mucosa (54.1 vs. 22.33 μm, p < 0.05), and inner circular (743.65 vs. 482.67 μm, p < 0.05) and outer longitudinal (570.68 vs. 330.33 μm, p < 0.05) smooth muscular layers of the muscularis externa was noted only in cat patients with ≥6 months compared to controls. Similarly, fewer ganglion cells (0.93 vs. 2.87, p < 0.005) and more necrotized myocytes (2.25 vs. 0.07, p < 0.005) were observed in cats with ≥6 months. In contrast to <6 months, the majority of cats (94.4%) with ≥6 months duration did not show any response to medical treatment and therefore underwent surgery with favorable results. In conclusion, this study suggests that the duration of clinical signs should be considered in conjunction with maximal colon scores to evaluate cats for idiopathic megacolon and determine the level of treatment. Functional abnormalities of the colonic smooth muscles may be a possible cause of idiopathic megacolon in cats

Regeneration, Cardenolide and Flavonoid Production from In Vitro Cultures of Cynanchum acutum L. (Asclepiadaceae)

Summary: Callus was produced from hypocotyl sections of in vitro germinated seedlings of Cynanchum acutum on Murashige and Skoog media (1962) containing 0.5 -4.0 mg/l a-Naphthalene acetic acid in combination with 0.2-1.0 mg/l Benzyl adenine. After 12 weeks in culture both fresh and dry weights (g) were significantly higher on 0.5 mg/l NAA and 0.2 mg/l BA. Cardiac glycoside concentration was highest (1.2 mg/g DW) on the same growth regulators combination. Flavonoids were highest (0.198 mg/g) on 0.5mg/l NAA and 1.0 mg/l BA. Twenty eight weeks old callus gave highest cardiac glycosides (1.3 mg/g) on media lacking BA and 0.5 mg/l NAA. Flavonoids concentration (0.27 mg/g) was highest on the same auxin concentration in the presence of 0.2 mg/l BA. Regeneration from callus cultures was obtained when 8-weeks old callus was subcultured on MS hormone free media for 6 weeks. Shoots were rooted on MS supplemented with 0.1 mg/l NAA and acclimatized in growth chamber. Adventitious shoots showed significantly higher CG (6.5 and 4.3 mg/g) than the wild plants (2.8), while regenerants gave comparable concentration (2.3) to the wild. Flavonoids were slightly lower in concentration in adventitious shoots (0.19) and regenerants (0.18) than the wild plant (0.27). Five cell lines were initiated from 8 weeks old individual callus pieces on NAA and BA containing media. Twenty weeks old cell line (1) showed higher CG (3.46) than the wild type and slightly lower flavonoid content (0.149). Plating of 12weeks old suspension on MS containing NAA and BA followed by hormone free media resulted in shoot regeneration, that were rooted and acclimatized. This represents the first report for regeneration from in vitro culture of C. acutum, as well as, the production of cardenolides and flavonoids from cultures to concentrations that are comparable to wild plants

Prosopis juliflora leave extracts induce cell death of MCF-7, HepG2, and LS-174T cancer cell lines

Prosopis juliflora (P. juliflora) is a widespread phreatophytic tree, which belongs to the Fabaceae family. The goal of the present study is to investigate the potential anti-cancer effect of P. juliflora leave extracts and to identify its chemical composition. For this purpose, MCF-7 (breast), HepG2 (liver), and LS-174T (colorectal) cancer cell lines were cultivated and incubated with various concentrations of P. juliflora leave extracts, and its impact on cell viability, proliferation, and cell cycle stages was investigated. P. juliflora leave extracts induced concentration-dependent cytotoxicity against all tested cancer cell lines. The calculated IC50 was 18.17, 33.1 and 41.9 μg/ml for MCF-7, HePG2 and LS-174T, respectively. Detailed analysis revealed that the cytotoxic action of P. juliflora extracts was mainly via necrosis but not apoptosis. Moreover, DNA content flow cytometry analysis showed cell-specific anti-proliferative action and cell cycle stages arrest. In order to identify the anti-cancer constituents of P. juliflora, the ethyl extracts were analyzed by liquid chromatography-mass spectrometry. The major constituents identified in the ethyl extracts of P. juliflora leaves were hydroxymethyl-pyridine, nicotinamide, adenine, and poly-(methyl methacrylate) (PMMA). In conclusion, P. juliflora ethyl acetate extracts have a potential anti-cancer effect against breast adenocarcinoma, hepatocellular carcinoma, and colorectal adenocarcinoma, and is enriched with anti-cancer constituents

Manufactured Nano-Objects Confer Viral Protection against Cucurbit Chlorotic Yellows Virus (CCYV) Infecting Nicotiana benthamiana

Nanotechnology has emerged as a new tool to combat phytopathogens in agricultural crops. Cucurbit chlorotic yellows virus (CCYV) mainly infects Solanaceae crops and causes significant crop losses. Nanomaterials (NMs) may have efficacy against plant viruses, but the mechanisms underlying complex nanomaterials-plant-virus interactions remain elusive. We challenged Nicotiana benthamiana plants with GFP-tagged CCYV and observed morphological, physiological, and molecular changes in response to 21-d foliar exposure to nanoscale Fe and Zn and C60 fullerenes at 100 mg/L concentration for 21 days. We observed that in response to C60 (100 mg/L) treatment, plants displayed a normal phenotype while the viral infection was not seen until 5 days post-inoculation. On the contrary, Fe and Zn were unable to suppress viral progression. The mRNA transcriptional analysis for GFP and viral coat protein revealed that the transcripts of both genes were 5-fold reduced in response to C60 treatment. Evaluation of the chloroplast ultrastructure showed that NMs treatment maintained the normal chloroplast structure in the plants as compared to untreated plants. C60 upregulated the defense-related phytohormones (abscisic acid and salicylic acid) by 42–43%. Our results demonstrate the protective function of carbon-based NMs, with suppression of CCYV symptoms via inhibition of viral replication and systemic movement