A stand-alone Zero-Liquid-Discharge greenhouse model with rainwater harvesting capability

This is the author accepted manuscriptGlobal warming is a prevalent topic throughout the world. The IPCC predicts that the maximum potential global temperature increase will be 4.8 oC by 2100. It has been concluded that a temperature rise of 1.4 oC or higher will have statistically significant impacts on global precipitation levels. Therefore, there is a need to investigate the future trends of precipitation and subsequent irrigation methods. This study will discuss a new multi-functional zero liquid discharge (ZLD) system for a greenhouse, incorporating a humidification dehumidification (HDH) mechanism, solar still desalination and rainwater harvesting. The focus of this paper is on analysing the water production of the system. Although previous literature discusses the inefficiency of solar still (SS) desalination, the fresh water produced during similar experiments has shown otherwise, desalinating 0.95 L/m²/hr of saline water. Using multiple panels could therefore give a substantial output of distilled water for certain usage such as agriculture. Implementing solar stills of large surface area would also allow the collection of rainwater thus increasing the total water productivity of the system. The ZLD system aims to produce no waste product and use the output brine water for aquaculture and salt cultivation.British CouncilScience & Technology Development Fund (STDF), Egyp

A novel stand-alone solar-powered agriculture greenhouse-desalination system; increasing sustainability and efficiency of greenhouses

This is the author accepted manuscript.The countries in the Middle East and North Africa (MENA) region are suffering from the scarcity of freshwater resources. With the economic development and population growth, planning the additional water supplies is critical for this region. Desalination of saline water is, therefore, considered as a strategic alternative water resources and technology to be adopted in MENA region. On the other hand, open field agriculture in such conditions is not economical particularly with high ambient temperature and solar intensity. Agriculture Greenhouses (GH) present a suitable alternative for different plants growth for the region’s desert. In most cases GHs can reduce about 90% of irrigating water demand compared open field. With the available high solar energy, integration of solar – GH – desalination presents a real challenge and is the field of newly funded N-M R&D proposal. This paper presents an integration of solar energy, agriculture GH and suitable desalination processes targeting the development and pilot testing of a novel stand-alone system that grows its energy and irrigation water demand.British CouncilScience & Technology Development Fund (STDF), Egyp

Radio asymmetry in 3C99

The N-galaxy 3C99, a Compact Steep-spectrum Source showing a triple asymmetric structure, has been observed with several arrays of radio telescopes at sub-arcsecond resolution. New images from MERLIN, European VLBI Network and the Very Long Baseline Array show that the source components detected in the central region of 3C99 have steep spectral indices, making it difficult to determine which of them is the core. The asymmetric radio structure of 3C99 is explained using the Scheuer-Baldwin continuous streaming model with a rather large difference in the interstellar medium density on the two sides of the central region. The age of 3C99 has been estimated; the source is found younger than 10^6 years.Comment: 18 pages, plain tex, plus 8 figures, accepted by A&

Analysing greenhouse ventilation using Computational Fluid Dynamics (CFD)

This is the author accepted manuscript. The final version is available from UKACM via the link in this recordGreenhouses (GH) are used to shield the crops from excessive cold or heat. They are used for growing certain types of cultivations during the year round. The aim of this study is to design a greenhouse using solar-powered technology to produce a Zero-Liquid-Discharge (ZLD) by using Solar Stills and adding condensers to dehumidify the excess vapoured water. This allows to have small-scale plants to reduce the cost of water treatment while increasing its sustainability. Computational fluid dynamics was used to find the best locations for the dehumidifiers in the GH and design the necessary ventilation. This can help to plan ahead and evaluate the optimal amount of produced water for different sizes of greenhouse before they are constructed physically.British Council - EgyptScience & Technology Development Fund (STDF), Egyp

The heating mechanism for the warm/cool dust in powerful, radio-loud AGN

The uncertainty surrounding the nature of the heating mechanism for the dust that emits at mid- to far-IR (MFIR) wavelengths in active galaxies limits our understanding of the links between active galactic nuclei (AGN) and galaxy evolution, as well as our ability to interpret the prodigious infrared and sub-mm emission of some of the most distant galaxies in the Universe. Here we report deep Spitzer observations of a complete sample of powerful, intermediate redshift (0.05 < z < 0.7) radio galaxies and quasars. We show that AGN power, as traced by [OIII]5007 emission, is strongly correlated with both the mid-IR (24 micron) and the far-IR (70 micron) luminosities, however, with increased scatter in the 70 micron correlation. A major cause of this increased scatter is a group of objects that falls above the main correlation and displays evidence for prodigious recent star formation activity at optical wavelengths, along with relatively cool MFIR colours. These results provide evidence that illumination by the AGN is the primary heating mechanism for the dust emitting at both 24 and 70 microns, with starbursts dominating the heating of the cool dust in only 20 -- 30% of objects. This implies that powerful AGN are not always accompanied by the type of luminous starbursts that are characteristic of the peak of activity in major gas-rich mergers.Comment: 13 pages, 3 figures. Accepted for publication in astrophysical journal letter

The first VLBI image of an Infrared-Faint Radio Source

Context: To investigate the joint evolution of active galactic nuclei and star formation in the Universe. Aims: In the 1.4 GHz survey with the Australia Telescope Compact Array of the Chandra Deep Field South and the European Large Area ISO Survey - S1 we have identified a class of objects which are strong in the radio but have no detectable infrared and optical counterparts. This class has been called Infrared-Faint Radio Sources, or IFRS. 53 sources out of 2002 have been classified as IFRS. It is not known what these objects are. Methods: To address the many possible explanations as to what the nature of these objects is we have observed four sources with the Australian Long Baseline Array. Results: We have detected and imaged one of the four sources observed. Assuming that the source is at a high redshift, we find its properties in agreement with properties of Compact Steep Spectrum sources. However, due to the lack of optical and infrared data the constraints are not particularly strong.Comment: Accepted for publication in Astronomy and Astrophysics, 5 pages, needs aa.cl

[OII] Emission, Eigenvector 1 and Orientation in Radio-quiet Quasars

We present supportive evidence that the Boroson and Green eigenvector 1 is not driven by source orientation. Until recently it was generally accepted that eigenvector 1 does not depend on orientation as it strongly correlates with [OIII]5007 emission, thought to be an isotropic property. However, recent studies of radio-loud AGN have questioned the isotropy of [OIII] emission and concluded that [OII]3727 emission is isotropic. In this paper we investigate the relation between eigenvector 1 and [OII] emission in radio-quiet BQS (Bright Quasar Survey) quasars, and readdress the issue of orientation as the driver of eigenvector 1. We find significant correlations between eigenvector 1 and orientation independent [OII] emission, which implies that orientation does not drive eigenvector 1. The luminosities and equivalent widths of [OIII] and [OII] correlate with one another, and the range in luminosities and equivalent widths is similar. This suggests that the radio-quiet BQS quasars are largely free of orientation dependent dust effects and ionization dependent effects in the narrow-line region. We also conclude that neither the [OIII] emission nor the [OII]/[OIII] ratio are dependent on orientation in our radio-quiet BQS quasar sample, contrary to recent results found for radio-loud quasars.Comment: 24 pages, 12 figures, accepted for publication in Ap

The origin of the infrared emission in radio galaxies II: analysis of mid- to far-infrared Spitzer observations of the 2Jy sample

We present an analysis of deep mid- to far-infrared (MFIR) Spitzer photometric observations of the southern 2Jy sample of powerful radio sources (0.05 < z < 0.7), conducting a statistical investigation of the links between radio jet, AGN, starburst activity and MFIR properties. This is part of an ongoing extensive study of powerful radio galaxies that benefits from both complete optical emission line information and a uniquely high detection rate in the far-infrared (far-IR). We find tight correlations between the MFIR and [OIII] emission luminosities, which are significantly better than those between MFIR and extended radio luminosities, or between radio and [OIII] luminosities. Since [OIII] is a known indicator of intrinsic AGN power, these correlations confirm AGN illumination of the circum-nuclear dust as the primary heating mechanism for the dust producing thermal MFIR emission at both 24 and 70 microns. We demonstrate that AGN heating is energetically feasible, and identify the narrow line region clouds as the most likely location of the cool, far-IR emitting dust. Starbursts make a major contribution to the heating of the cool dust in only 15-28% of our targets. We also investigate the orientation dependence of the continuum properties, finding that the broad- and narrow-line objects in our sample with strong emission lines have similar distributions of MFIR luminosities and colours. Therefore our results are entirely consistent with the orientation-based unified schemes for powerful radio galaxies. However, the weak line radio galaxies (WLRG) form a separate class of objects with intrinsically low luminosity AGN in which both the optical emission lines and the MFIR continuum are weak.Comment: 29 pages, 5 figures, Accepted for publication in The Astrophysical Journa

Decarbonisation using hybrid energy solution: case study of Zagazig, Egypt

This is the final version. Available on open access from the publisher via the DOI in this record.In this study, an analysis is carried out to determine the optimal application of multiple renewable energy resources, namely wind and solar, to provide electricity requirements for green smart cities and environments. This was done to determine the potential of renewable energy to provide clean, economically viable energy for the case study of Zagazig, located at 30◦340 N 31◦300 E in the North East of Egypt. The relevant data surrounding the production of energy were collected, including the meteorological data from NASA, and specifications regarding renewable resources including solar panels, wind turbines, and storage batteries. Then a hybrid model was constructed consisting of Photovoltaics (PV) panels, wind turbines, a converter, and storage batteries. Once the model was constructed, meteorological data were added alongside average daily demand and cost of electricity per kWh. The optimal solution for Zagazig consisted of 181,000 kW of solar panels feeding directly into the grid. This system had the lowest Net Present Cost (NPC) of the simulations run of US$1,361,029,000 and a net reduction of 156,355 tonnes of CO2 per year.British CouncilScience, Technology, and Innovation Funding Authority (STIFA) of Egyp