Brackish groundwater treatment by reverse osmosis in Jordan

Jordan is characterised by an arid to semi-arid climate and its population is increasing at an annual rate of 3.6%. With such a high population growth rate and fast social-economical development, water demand and wastewater production are steeply increasing, and the gap between water supply and demand is getting wider. Furthermore, the constraints for water resources development are also rising due to high investment costs and water quality degradation due to over-exploitation of aquifers. Desalination of Red Sea water by reverse osmosis (RO) and/or brackish groundwater desalination by nanofiltration or RO might be technically and economically viable to cope with water scarcity and overcome the water deficit in Jordan. The technical-economical feasibility of brackish groundwater treatment by RO for potable water production was investigated in this work. Brackish groundwater samples were collected from the Zarqa basin, Jordan, and characterised in terms of pH, conductivity, total solids, total dissolved solids, total suspended solids, and volatile solids. The water samples were pre-treated through a microfiltration cartridge (5 μm pore diameter) in order to eliminate the suspended matter. A pilot plant equipped with a FilmTec RO membrane (SW30-2521) was operated at 20-30 bar, 40°C, natural pH and up to a water recovery ratio of 77.5%. The results showed that RO is actually efficient since it highly reduced the content of organic and inorganic matters present in raw waters (rejections >98.5%) at a relatively affordable price (0.26 €/m³). This study contributes to the development of efficient technologies to produce affordable potable water in Mediterranean countries where the threat of water shortages is a severe problem.     

Modeling of the mixing of monodisperse particles using a stationary DEM-based Markov process

This paper provides a discussion on the modeling of granular mixing using Markov chain theory. Previous papers on this topic are either based on restrictive underlying assumptions about the flow structure or are limited to a small number of states. In this paper, a generalized approach for the construction of a multidimensional state space first-order Markov chain that represents the mixing of monodisperse particles is introduced. The transition probability matrix is computed directly using results obtained from a discrete element model. This work shows that, if accurate measurements of the state of the system are available, the associated Markov operator leads to a good estimate of the particle dynamics in the system.     

CMOS photodetector systems for low-level light applications

Electron beam induced second harmonic generation (SHG) is studied in Er³⁺ doped PbO–GeO₂ glasses containing silver nanoparticles with concentrations that are controlled by the heat-treatment of the samples. The SHG is observed at T = 4.2 K using a p-polarized laser beam at 1064 nm. Enhancement of the SHG is observed in the samples that are submitted to electron beam incidence. The highest value of the nonlinear susceptibility, 2.08 pm/V, is achieved for the sample heat-treated during 72 h and submitted to an electron beam current of 15 nA. The samples that were not exposed to the electron beam present a susceptibility of ≈0.5 pm/V.     

Cover Picture: Dynamic Imaging of Functionalized Multi‐Walled Carbon Nanotube Systemic Circulation and Urinary Excretion (Adv. Mater. 2/2008)

Multiwalled carbon nanotubes (MWNTs) made highly water‐dispersible by organic functionalization and radiolabeled with Indium‐111 were shown to translocate through the kidney glomerular filter. On p. 225, multinational, multicenter research led by Kostas Kostarelos on dynamic imaging and tissue distribution of MWNTs in live animals is presented. The cover image presents a single plane single photon computed tomography whole body image of a rat following intravenous injection with the In‐111 labeled MWNTs as seen through a 3D carbon NT projection. The radioactivity from carbon NTs was mainly localized in the kidneys, and accumulated in the bladder before clearance in the urine.     

A multisampling time-domain CMOS imager with synchronous readout circuit

A novel multisampling time-domain architecture for CMOS imagers with synchronous readout and wide dynamic range is proposed. The proposed multisampling architecture requires only a single bit per pixel memory instead of 8 bits which is typical for time-domain active pixel architectures. The goal is to obtain a time-domain imager with high dynamic range that requires lower number of transistors per pixel in order to achieve higher fill-factor. The maximum frame rate is analyzed as a function of number of bits and array size. The analysis shows that it is possible to achieve high frame rates and operate in video mode having 10 bit pixel data resolution. Also, we present analysis of the impact of comparator offset voltage on the fixed pattern noise. The architecture was implemented in an imager prototype with 32 × 32 pixel array fabricated in AMS CMOS 0.35 μm and was characterized for sensitivity, noise and color response. The pixel size is 30 μm × 26 μm and it is composed of an n+/psub photodiode, a comparator and a D flip-flop with a 16% fill-factor.     

酶水解苦味肽对大黄鱼白细胞与溶菌酶活性的影响

目的探究酶水解苦味肽对大黄鱼白细胞与溶菌酶活性的影响。方法分别利用木瓜蛋白酶、胰蛋白酶、胃蛋白酶,碱性蛋白酶和风味蛋白酶酶解鮸鱼鱼肉制备苦味最高的苦味肽。以幼大黄鱼为实验对象,分别设置4个不同的组(对照组、低剂量组、中剂量组、高剂量组),对其进行腹腔注射苦味肽,观察8周后采血检测,以白细胞/总血细胞的平均比率和溶菌酶活性为指标评价苦味肽对大黄鱼先天免疫系统的作用效果。结果胃蛋白酶水解产生的苦味肽苦味最高。对照组的白细胞/总血细胞的平均比率为14.6%,低剂量组(0.6 mg/鱼)为28.86%,中剂量组(1.2 mg/鱼)为35%,高剂量组(2.4 mg/鱼)为29.3%。在白细胞对乳胶颗粒的体外吞噬作用实验中,对照组与测试组的吞噬指数分别为1.15(0mg/L),1.88(0.4mg/L),3.84(0.8mg/L),5.94(1.2mg/L)。溶菌酶在60min内的相对裂解活性分别为0.17、0.101、0.307和0.198。与对照组相比苦味肽可以提高大黄鱼的免疫力,当注射剂量为1.2mg时,吞噬与溶菌酶活性都显著升高,可初步确定最佳注射剂量为1.2mg。结论苦味肽可以通过多途径有效地提高天然免疫的作用,可以降低大黄鱼疾病的发生,值得进一步研究。     

Post-translational modifications in glycosylation status during epididymal passage and significance in fertility of a 33 kDa glycoprotein (MEF3) of rhesus monkey (Macaca mulatta)

The present study reports data on post-translational modifications in the glycosylation status during epididymal passage and significance in fertility of a 33 kDa glycoprotein of rhesus monkey (Macaca mulatta), designated as MEF3 (monkey epididymal fluid protein 3). MEF3 exhibited strong affinity for N-linked alpha-D-mannose groups and O-linked N-Ac-galactosamine linkages in epididymal fluids and exhibited moderate affinity for N-Ac-glucosaminylated (wheat germ agglutinin), fucosylated (Tetragonolotus purpurea), and N-Ac-galactosamine (peanut agglutinin) residues on more mature corpus and caudal spermatozoa in a maturation-dependent manner on Western blots probed with specific biotinylated lectins. Polyclonal antiserum raised against affinity-purified MEF3 from caudal epididymal fluid (CEF) cross-reacted specifically with CEF and caudal sperm membrane of macaque and with Triton X-100 extract of ejaculated human spermatozoa, suggesting the existence of antigenically related components in both species. The tangled agglutination caused by anti-33 kDa serum of human spermatozoa, along with localization of MEF3 on entire sperm surface of epididymal and testicular sperm of monkey and human spermatozoa, suggest the significance of MEF3 in sperm function. The 100% inhibition of fertility of immunized female rabbits with this protein in vivo and inhibition of human sperm penetration in zona-free hamster eggs in vitro suggests the functional significance of MEF3 in fertility. Together, these results clearly indicate that MEF3 has potential significance as a target for antibodies that inhibit sperm function and fertility.     

Effect of Loading Position and Storage Duration on the Textural Properties of Eggplant

Eggplant has a very limited shelf life and, like other vegetables, is susceptible to different types of damage during and after harvest operations. Besides, eggplant is inhomogeneous considering its inner construction point of view. It is therefore important to specify how storage might affect their mechanical properties and how they vary in morphology. In this work, eggplants were divided into three portions along the longitudinal axis and their textural properties were separately investigated using different types of test over a 10-day period of storage. The results showed that the tension strength, rupture force and Young’s modulus of skin tissue decreased with increasing the length of storage period, and they were generally different in the different portions of the fruit that were sampled. The values of Young’s modulus and rupture force of pulp tissue taken from compression tests decreased from 1.466 to 0.821 MPa and 20.70 to 17.66 N for upper section, 0.637 to 0.536 MPa and 15.33 to 13.13 N for middle section and 0.518 to 0.422 MPa and 14.19 to 12.19 N for bottom section, respectively, with the increase in storage period. Similarly, as the samples were stored longer, the Young’s modulus and rupture force of their combined skin and pulp tissues, obtained from penetration tests, decreased from 3.01 to 2.02 MPa and 31.21 to 24.95 N for upper section, 2.59 to 1.66 MPa and 28.64 to 21.66 N for middle section and 1.91 to 1.15 MPa and 23.18 to 17.37 N for bottom section, respectively.     

Computational Fluid Dynamics Simulation of Supersonic Oxygen Jet Behavior at Steelmaking Temperature

Supersonic oxygen jets are used in steelmaking and other different metal refining processes, and therefore, the behavior of supersonic jets inside a high temperature field is important for understanding these processes. In this study, a computational fluid dynamics (CFD) model was developed to investigate the effect of a high ambient temperature field on supersonic oxygen jet behavior. The results were compared with available experimental data by Sumi et al. and with a jet model proposed by Ito and Muchi. At high ambient temperatures, the density of the ambient fluid is low. Therefore, the mass addition to the jet from the surrounding medium is low, which reduces the growth rate of the turbulent mixing region. As a result, the velocity decreases more slowly, and the potential core length of the jet increases at high ambient temperatures. But CFD simulation of the supersonic jet using the k−ε turbulence model, including compressibility terms, was found to underpredict the potential flow core length at higher ambient temperatures. A modified k-ε turbulence model is presented that modifies the turbulent viscosity in order to reduce the growth rate of turbulent mixing at high ambient temperatures. The results obtained by using the modified turbulence model were found to be in good agreement with the experimental data. The CFD simulation showed that the potential flow core length at steelmaking temperatures (1800 K) is 2.5 times as long as that at room temperature. The simulation results then were used to investigate the effect of ambient temperature on the droplet generation rate using a dimensionless blowing number.