Prevalence and public health significance of aluminum residues in milk and some dairy products

Sixty random samples of bulk farm milk, market milk, locally manufactured processed cheese, and milk powder were collected to be analyzed for aluminum (Al) concentration using graphite furnace atomic absorption spectrometry (GFAAS). The results were compared with provisional acceptable permissible limits (PAPLs). The maximum estimated dietary intake (MEDI) of Al for the examined samples was calculated. In addition, an experimental study was conducted to determine the possible leaching of Al from cookware in milk during boiling. The obtained results showed that Al concentration in examined bulk farm milk samples was found to be negligible. In contrast, market milk revealed higher concentration, 65.0% of the examined samples were above the PAPLs. The results revealed significant difference of Al concentration among them. The Al levels in processed cheese wrapped in Al foil were significantly higher than those found in samples packed in glass containers with a significant difference of Al concentration between them. Also, 20% of the examined milk powder samples exceeded the PAPLs (0.01 to 0.4 mg/kg). The MEDI for Al in bulk farm milk, control market milk, market milk boiled in Al cookware, market milk boiled in stainless-steel cookware, processed cheese wrapped in Al foil, processed cheese packed in glass containers, and milk powder were calculated as 3.0%, 61.0%, 63.0%, 61.0%, 428.0%, 220.0%, and 166.0% from "PTDI," respectively. The results of the experimental study showed no marked significant differences of Al concentration between market milk (control group) and those boiled in Al cookware, as well as to those boiled in stainless-steel cookware. PRACTICAL APPLICATION: The results of the present study indicate that Al level in milk kept in Al containers and dairy products packed in Al foil is beyond the permissible limits, suggesting health hazard. Therefore, all milk cans should be constructed of stainless steel, prevent the entrance of tap water into milk, and the processed cheese should be packed in glass containers and not wrapped in Al foil. Leaching of Al increased to a significant percent more during storage than during boiling, so milk should be kept in stainless steel or glass containers in the refrigerator.     

Investigating the effect of various fin geometries on the thermal performance of a heat sink under natural convection

Experimentally investigates heat dissipation by different longitudinal fins fitted to a cylindrical heat sink under natural convection conditions. Five aluminum fin configurations at base temperatures (70°C, 85°C, 100°C, and 115°C) were studied. The first fin was plain (fin1), while second fin had a triangular edge (fin2). The rest fins have the same triangular edge but with six 1cm circular perforations near the edge (fin3). While the perforations in fin4 were in the middle longitudinal fin length. The last fin (fin5) had twelve 0.5 cm circular perforations distributed into two columns. The measurements were validated with theoretical correlation with an acceptable deviation. The results showed that fin2, fin3, fin4, and fin5 dissipate more heat by 2.4%, 8.7%, 11.4%, and 5% than the flat fin with 9.8%, 11.85%, 11.85%, and 10.82% weight reduction, respectively. The heat transfer coefficient enhanced by 7.98%, 16.81%, 12.35%, and 5.44% for fin5, fin4, fin3, and fin2, respectively. Large circular perforation was more effective to dissipate heat especially when located near the heat source as in fin4 which gives the best heat dissipation with more weight reduction. The proposed fins efficiency were greater than 92%.     

Opportunistic interference alignment for three‐tier partially connected heterogeneous networks

With the expected increase in the number of connected devices, heterogeneous networks (HetNets) technology has gained great attention in next generation wireless networks. The deployment of such low power nodes in the same geographical area and using the same allocated frequency introduces significant interference among different nodes in the network. In this paper, we propose a two‐stage opportunistic interference alignment (OIA) scheme for the three‐tier downlink HetNet that targets user scheduling along with mitigating intertier and intratier interference signals. Two cascaded precoding matrices as well as two cascaded postcoding matrices are used to perform the two‐stage interference alignment (IA) operation. The outer precoding/postcoding matrix pair are designed using the rank‐constrained rank minimization (RCRM) to minimize the interference among the users associated to the same tier. Simulations show that the proposed scheme outperforms other conventional schemes in terms of the sum rate and the sum achieved degrees of freedom (DoF).     

LRV: A Tool for Academic Text Visualization to Support the Literature Review Process

Text visualization is concerned with the representation of text in a graphical form to facilitate comprehension of large textual data. Its aim is to improve the ability to understand and utilize the wealth of text-based information available. An essential task in any scientific research is the study and review of previous works in the specified domain, a process that is referred to as the literature survey process. This process involves the identification of prior work and evaluating its relevance to the research question. With the enormous number of published studies available online in digital form, this becomes a cumbersome task for the researcher. This paper presents the design and implementation of a tool that aims to facilitate this process by identifying relevant work and suggesting clusters of articles by conceptual modeling, thus providing different options that enable the researcher to visualize a large number of articles in a graphical easy-to-analyze form. The tool helps the researcher in analyzing and synthesizing the literature and building a conceptual understanding of the designated research area. The evaluation of the tool shows that researchers have found it useful and that it supported the process of relevant work analysis given a specific research question, and 70% of the evaluators of the tool found it very useful.     

Groundwater flow model for the Nubian aquifer in the Khartoum area,Sudan

The interbedded sands and mudstones of the Nubian aquifer provide Khartoum city with more than 43% of its drinking water. The recharge is mainly from the Nile system into semi-confined to confined conditions at depths from 10 m close to the Nile to more than 60 m away from the river. The paper briefly discusses the hydrogeology of the area and the modeling undertaken, which indicates that significant groundwater depletion will be exacerbated over the next 26 years if the present extraction rate continues unchecked. It is recommended that sensitivity studies are undertaken with continuous monitoring to create a computer database, such that appropriate levels of abstraction can be maintained.     

Evaluating Algibon adsorbent and adsorption kinetics for launderette water treatment: towards sustainable water management

Grey water from commercial laundry facility was used for treatment to substitute the conventional water sources. Algibon, A800 derived from mesoporous alginic acid and Starbon S300, carbonaceous mesoporous polysaccharide‐derived materials, silica gel (SG) and activated carbon (AC) were used for the treatment of wastewater. The optimum adsorbent dosing and pH value for each adsorption system are defined. The adsorption efficiency are in the order of A800 > SG > AC > S300 and the removal rate reached to 91% when A800 was used. Furthermore, the reaction followed the second‐order kinetic model and the rate constant is high when A800 adsorbent is applied.     

Experimental and modelling study of twin cells with latent heat storage walls

An experimental and numerical simulation study of the application of phase change materials (PCMs) in building components is presented for thermal management of a passive solar test-room. The experimental study was conducted in an outdoor test cell constituted of two small rooms separated with a wall containing PCM. A specific wall made of hollow glass bricks filled with PCM was studied. Three PCMs were tested: fatty acid, paraffin, and salt hydrate whose melting temperatures are 21 °C, 25 °C and 27.5 °C respectively.Indoor and outdoor temperatures were measured with thermocouples. Ten fluxmeters located at the centre of each wall allowed us to measure the heat fluxes across the walls. Tests were carried out in real climatic conditions.A one-dimensional numerical model has been developed to simulate the transient heat transfer process in the walls. Reasonable agreement between the simulation and the experimental results was observed.     

DETERMINATION OF CINACALCET HYDROCHLORIDE BY CAPILLARY ELECTROPHORESIS WITH PHOTODIODE ARRAY DETECTION

This article reports a validated stability-indicating capillary electrophoresis method using a photodiode array detector at 220 nm for the determination of cinacalcet hydrochloride. The best electrophoretic separation between the analyte and internal standard (lamotrigine) was achieved within 5 min in a deactivated fused silica capillary (55 cm effective length × 75 µm internal diameter) maintained at 24°C using a background electrolyte solution consisted of phosphate buffer (50 mM, pH 6.4):methanol (95:5, v/v) at a separation voltage of 30 kV. The linear range of the method was 0.5–30 µg/mL (r = 0.9999) with limits of detection and quantitation of 0.1 and 0.5 µg/mL, respectively. The assay precision and accuracy were favorable as the relative standard deviations did not exceed 1.09%, and the recovery values were 98.99–100.33 ± 0.19–1.09%. The induced degradation products, when any, did not interfere with the detection of analyte. The proposed method was successfully applied for the determination of cinacalcet hydrochloride in bulk and pharmaceutical formulations; the percentage recovery values were 98.16–102.00 ± 0.24–1.08%. The results demonstrated the value of the method.     

Z-scheme g-C3N4 nanosheet photocatalyst decorated with mesoporous CdS for the photoreduction of carbon dioxide

Herein, novel mesoporous CdS nanoparticle (NP)-incorporated porous g-C₃N₄ nanosheets with large surface areas and varying CdS NP percentages were constructed for the first time. The synergistic effect of mesoporous CdS NPs and porous g-C₃N₄ nanosheets indicated effective charge carrier separation and promoted CO₂ photoreduction to form CH₃OH upon illumination. The highest yield of CH₃OH over 3% CdS-g-C₃N₄ heterostructures was determined to be approximately 1735 μmol g^?1, which was 3.8- and 5.50 times greater than those of mesoporous CdS NPs and pristine g-C₃N₄ nanosheets, respectively. In addition, the mesoporous 3%CdS-g-C₃N₄ heterostructure showed an outstandingly enhanced CO₂ photoreduction rate of 192.7 μmol g^?1 h^?1, which was estimated to be ~4.1 and 5.9- times better than CdS (47.1 μmol g^?1 h^?1) and pristine g-C₃N₄ (32.6 μmol g^?1 h^?1), respectively. The photoreduction performance was retained at approximately 94.7% after five cycles of illumination for 45 h. The remarkable synthesized mesoporous CdS-g-C₃N₄ heterostructure played an essential role, with its narrow bandgap and high surface area enabling improved photoinduced carrier separation and a widened range of light absorption. A plausible mechanism for CO₂ photoreduction by the mesoporous CdS-g-C₃N₄ heterostructure was proposed and verified by photoelectrochemical and photoluminescence measurements.