DESIGN, CONSTRUCTION AND PERFORMANCE EVALUATION OF AN ALMOND KERENEL EXTRACTION MACHINE

A low-cost Almond (Prunus dulcis) kernel extraction machine was locally designed, manufactured and evaluated. Kernel extraction by the machine was conducted by first crushing the nut, and then separating seeds from a shell. The performance of the developed machine was evaluated in terms of machine productivity, cracking efficiency, kernel breakage and specific energy requirements. The evaluation was conducted at roller speeds (ranging from 0.5 to 1 m/s), rollers clearance (ranging from 14 to 25 mm) and two different roller casing materials (rubber and metal mesh). Results revealed that the increase of the roller speed was found to increase the machine productivity. However, it caused a decrease in the kernel breakage, cracking efficiency, energy requirements and the extraction cost. At all levels of roller speeds and both casing materials, the clearance between rollers of 16 mm resulted in lowest values of energy requirement, extraction cost and highest values of machine productivity. On the other hand, the clearance between rollers of 14 mm resulted in the maximum values of cracking efficiency. The use of rubber casing was found to increase the machine productivity, cracking efficiency and decrease the kernel breakage, energy requirements and extraction cost. 

Aerosol Climatology Over Nile Delta Based on MODIS, MISR and OMI Satellite Data

Since 1999 Cairo and the Nile delta region have suffered from air pollution episodes called the “black cloud” during the fall season. These have been attributed to either burning of agriculture waste or long-range transport of desert dust. Here we present a detailed analysis of the optical and microphysical aerosol properties, based on satellite data. Monthly mean values of Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol optical depth (AOD) at 550 nm were examined for the 10 yr period from 2000–2009. Significant monthly variability is observed in the AOD with maxima in April or May (_0.5) and October (_0.45), and a minimum in December and January (_0.2). Monthly mean values of UV Aerosol Index (UVAI) retrieved by the Ozone Monitoring Instrument (OMI) for 4 yr (2005–2008) exhibit the same AOD pattern. The carbonaceous aerosols during the black cloud periods are confined to the planetary boundary layer (PBL), while dust aerosols exist over a wider range of altitudes, as shown by Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) aerosol profiles. The monthly climatology of Multi-angle Imaging Spectro-Radiometer (MISR) data show that the aerosols during the black cloud periods are spherical with a higher percentage of small and medium size particles, whereas the spring aerosols are mostly large non-spherical particles. All of the results show that the air quality in Cairo and the Nile delta region is subject to a complex mixture of air pollution types, especially in the fall season, when biomass burning contributes to a background of urban pollution and desert dust

Dual-band multiple-element MIMO antenna system for next-generation smartphones

This work presents a cost-effective multiple-element multiple-input multiple-output (MIMO) antenna system for next-generation smartphones. The proposed antenna system is developed on a 0.8 mm thin FR-4 substrate with a relative permittivity of 4.4, which consists of one main board and two sideboards. The dimensions of the main board and the two side boards are 150 × 75 mm2 and 150 × 6 mm2, respectively. The radiating elements are printed on the sideboards to provide space for other radio frequency (RF) components to be embedded on the main board. The proposed antenna resonates at two distinct allotted 5G bands, i.e., 3.5 GHz and 5.4 GHz, with impedance bandwidths of 200 MHz and 700 MHz, respectively. The isolation between the antenna elements is noted to be >18 dB and >12 dB for the 3.5 GHz and 5.4 GHz frequency bands. In addition, the proposed MIMO antenna provides pattern and spatial diversity characteristics in both bands with good gain and efficiency. Furthermore, the MIMO parameters such as envelope correlation coefficient (ECC), mean effective gain (MEG), and channel capacity (CC) are calculated, and it is observed that the MIMO antenna offers good diversity performance for the bands of interest. A prototype is fabricated and measured to verify the numerical data. The simulated results were discovered to be in excellent agreement with the measured results. It is also observed that the proposed MIMO antenna system holds promising features, and can be utilized for future generations of smartphones.Princess Nourah bint Abdulrahman Universit