New and renewable energy and environmental engineering

There is an acute scarcity of potable water in many parts of the world, and especially in most of the Middle East region. Important advances have been made in desalination technology but its wide application is restricted by relatively high capital and input energy costs, even when solar energy is used. Until recently, flat-plate solar collectors have usually been employed to distill water in compact desalination systems. Currently, it is possible to replace these collectors by the more advanced evacuated tube collectors, which are now available on the market at a similar price. The research which is concerned with the development of a novel small scale solar water desalination technology, consists of experimental and theoretical investigations of the operation of a multi stage solar still desalination system coupled with a heat pipe evacuated tube solar collector with an aperture area of about 1.7 m(^2). The multi stage still was tested to recover latent heat from the evaporation and condensation processes in each of its four stages. A number of experimental tests were carried out using a laboratory rig to investigate its water production capacity. Solar radiation (insolation) during a mid-summer day in the Middle East region was simulated by an array of 110 halogen flood lights. Computational Fluid Dynamics (CFD) modeling of the evaporation and condensation processes in one of the still's stages was conducted using FLUENT 6.2 software. The simulation results demonstrate the importance of the various parameters affecting the total production rate of the solar still and provide detailed information on the temperature distribution and condensate formation inside the solar still. However, it was found that the CFD technique at this stage does not provide accurate quantitative predictions and results obtained can be used only for qualitative analysis. Hence, the use of a lumped parameter mathematical model was preferred for analysis and design purpose. A lumped parameter model has been developed to describe the system's operation. It consists of a system of ordinary differential equations of energy and mass conservation written for each stage of the still. A MATLAB computer program was written to solve the system of governing equations to simulate the evaporation and condensation processes and the experimental results were used to validate numerical predictions. The experimental and theoretical values for the total daily distillate output were found to be closely correlated. The test results demonstrate that the system produces about 9 kg of clean water per day and has a distillation efficiency of 90%. The overall efficiency is 33% due to the presence of heat losses in the system. However, this level of efficiency is greater of that for conventional solar stills. Following the experimental calibration of the lumped parameter model, this was used for determination of rational design parameters of the still and it was demonstrated that the performance of the system could be considerably improved to produce 11 kg/m(^2) of water per day if the number of stages and evaporation area were 4 and 1 m(^2), respectively. A water quality analysis was performed for the distilled water and the levels of total dissolved solids, electrical conductivity and pH were well within the range defined by the World Health Organization guidelines for drinking water. An economic study was also conducted for the system and it was shown that the distilled water costs of 0.016 US$/litre with a payback period of 6 months in the Middle East region conditions. This research demonstrates, empirically and theoretically, the potential role in the field of solar desalination of the multistage solar still coupled to the evacuated tube solar collector. Not only is this system a promising new technology but it could prove to be particularly appropriate in remote and rural areas. Simultaneously this system also uses a completely clean energy source and contributes to tackling environmental pollution, global carbon emissions and climate change problems

The Symptom Burden and Quality of Life in Cancer Patients in the Gaza Strip, Palestine: A Cross-Sectional Study

Objectives Cancer is the second leading cause of death in the Gaza Strip, Palestine, but there is an absence of evidence systematically assessing symptom burden and quality of life (QoL) using validated tools. Our objective was to assess associations between socio-demographic and disease-related characteristics, symptom burden and QoL in a sample of cancer patients accessing outpatient services in the Gaza Strip. Design A cross-sectional, descriptive survey using interviews and medical record review involving patients with cancer accessing oncology outpatient services at Al Rantisi Hospital and European Gaza Hospital (EGH) in the Gaza Strip was employed. Socio-demographic and disease-related data, the Lebanese version of the Memorial Symptom Assessment Scale (MSAS-Leb), and the Arabic version of the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-C30 (EORTC QLQ-C30) were collected. Multiple linear regression was used to judge the relative influence of determinants of QoL. Results Of 414 cancer patients approached, 385 patients consented to participation. The majority were women (64.7%) with a mean age of 52 years (SD = 16.7). Common cancer diagnoses were breast (32.2%), haematological (17.9%) and colorectal (9.1%). The median number of symptoms was 10 (IQR 1.5–18.5). Mean overall QoL was 70.5 (SD 19.9) with common physical and psychological symptoms identified. A higher burden of symptoms was associated with marital status, education and income. Limited access to both opioids and psychological support were reported. Conclusions A high symptom burden was identified in outpatients with cancer. Increasing provision and access to supportive care for physical and psychological symptoms should be prioritised alongside exploring routine assessment of symptom burden and QoL

Therapeutic potential of KLF2-induced exosomal microRNAs in pulmonary hypertension

Pulmonary arterial hypertension (PAH) is a severe disorder of lung vasculature that causes right heart failure. Homeostatic effects of flow-activated transcription factor Krüppel-like factor 2 (KLF2) are compromised in PAH. Here we show that KLF2-induced exosomal microRNAs, miR-181a-5p and miR-324-5p act together to attenuate pulmonary vascular remodeling and that their actions are mediated by Notch4 and ETS1 and other key regulators of vascular homeostasis. Expressions of KLF2, miR-181a-5p and miR-324-5p are reduced, while levels of their target genes are elevated in pre-clinical PAH, idiopathic PAH and heritable PAH with missense p.H288Y KLF2 mutation. Therapeutic supplementation of miR-181a-5p and miR-324-5p reduces proliferative and angiogenic responses in patient-derived cells and attenuates disease progression in PAH mice. This study shows that reduced KLF2 signaling is a common feature of human PAH and highlights the potential therapeutic role of KLF2-regulated exosomal miRNAs in PAH and other diseases associated with vascular remodelling

Light source selection for a solar simulator for thermal applications: A review

Solar simulators are used to test components and systems under controlled and repeatable conditions, often in locations with unsuitable insolation for outdoor testing. The growth in renewable energy generation has led to an increased need to develop, manufacture and test components and subsystems for solar thermal, photovoltaic (PV), and concentrating optics for both thermal and electrical solar applications. At the heart of any solar simulator is the light source itself. This paper reviews the light sources available for both low and high-flux solar simulators used for thermal applications. Criteria considered include a comparison of the lamp wavelength spectrum with the solar spectrum, lamp intensity, cost, stability, durability, and any hazards associated with use. Four main lamp types are discussed in detail, namely argon arc, the metal halide, tungsten halogen lamp, and xenon arc lamps. In addition to describing the characteristics of each lamp type, the popularity of usage of each type over time is also indicated. This is followed by guidelines for selecting a suitable lamp, depending on the requirements of the user and the criteria applied for selection. The appropriate international standards are also addressed and discussed. The review shows that metal halide and xenon arc lamps predominate, since both provide a good spectral match to the solar output. The xenon lamp provides a more intense and stable output, but has the disadvantages of being a high-pressure component, requiring infrared filtering, and the need of a more complex and expensive power supply. As a result, many new solar simulators prefer metal halide lamps

Inclusive and multiplicity dependent production of electrons from heavy-flavour hadron decays in pp and p-Pb collisions

Measurements of the production of electrons from heavy-flavour hadron decays in pp collisions at root s = 13 TeV at midrapidity with the ALICE detector are presented down to a transverse momentum (p(T)) of 0.2 GeV/c and up to p(T) = 35 GeV/c, which is the largest momentum range probed for inclusive electron measurements in ALICE. In p-Pb collisions, the production cross section and the nuclear modification factor of electrons from heavy-flavour hadron decays are measured in the p(T) range 0.5 < p(T) < 26 GeV/c at root s(NN) = 8.16 TeV. The nuclear modification factor is found to be consistent with unity within the statistical and systematic uncertainties. In both collision systems, first measurements of the yields of electrons from heavy-flavour hadron decays in different multiplicity intervals normalised to the multiplicity-integrated yield (self-normalised yield) at midrapidity are reported as a function of the self-normalised charged-particle multiplicity estimated at midrapidity. The self-normalised yields in pp and p-Pb collisions grow faster than linear with the self-normalised multiplicity. A strong p(T) dependence is observed in pp collisions, where the yield of high-p(T) electrons increases faster as a function of multiplicity than the one of low-p(T) electrons. The measurement in p-Pb collisions shows no p(T) dependence within uncertainties. The self-normalised yields in pp and p-Pb collisions are compared with measurements of other heavy-flavour, light-flavour, and strange particles, and with Monte Carlo simulations

Measurement of the non-prompt D-meson fraction as a function of multiplicity in proton-proton collisions at s \sqrt{s} = 13 TeV

The fractions of non-prompt (i.e. originating from beauty-hadron decays) D0 and D+ mesons with respect to the inclusive yield are measured as a function of the charged-particle multiplicity in proton-proton collisions at a centre-of-mass energy of √s = 13 TeV with the ALICE detector at the LHC. The results are reported in intervals of transverse momentum (pT) and integrated in the range 1 < pT < 24 GeV/c. The fraction of non-prompt D0 and D+ mesons is found to increase slightly as a function of pT in all the measured multiplicity intervals, while no significant dependence on the charged- particle multiplicity is observed. In order to investigate the production and hadronisation mechanisms of charm and beauty quarks, the results are compared to PYTHIA 8 as well as EPOS 3 and EPOS 4 Monte Carlo simulations, and to calculations based on the colour glass condensate including three-pomeron fusion

First measurement of Λc+ production down to pT=0 in pp and p-Pb collisions at sNN=5.02 TeV

The production of prompt Lambda+c baryons has been measured at midrapidity in the transverse momentum interval 0 < pT < 1 GeV/c for the first time, in pp and p–Pb collisions at a center-of-mass energy per nucleon-nucleon collision √s NN = 5.02 TeV. The measurement was performed in the decay channel Lambda+c → pK0S by applying new decay reconstruction techniques using a Kalman-Filter vertexing algorithm and adopting a machine-learning approach for the candidate selection. The pT -integrated Lambda+c production cross sections in both collision systems were determined and used along with the measured yields in Pb–Pb collisions to compute the pT -integrated nuclear modification factors R pPb and R AA of Lambda+c baryons, which are compared to model calculations that consider nuclear modification of the parton distribution functions. The Lambda+c /D0 baryon-to-meson yield ratio is reported for pp and p–Pb collisions. Comparisons with models that include modified hadronization processes are presented, and the implications of the results on the understanding of charm hadronization in hadronic collisions are discussed. A significant (3.7σ ) modification of the mean transverse momentum of Lambda+c baryons is seen in p–Pb collisions with respect to pp collisions, while the pT -integrated Lambda+c /D0 yield ratio was found to be consistent between the two collision systems within the uncertainties

Light (anti)nuclei production in Pb-Pb collisions at sNN=5.02 TeV

The measurement of the production of deuterons, tritons and 3 He and their antiparticles in Pb-Pb collisions at √s NN = 5.02 TeV is presented in this article. The measurements are carried out at midrapidity (|y| < 0.5) as a function of collision centrality using the ALICE detector. The pT -integrated yields, the coalescence parameters and the ratios to protons and antiprotons are reported and compared with nucleosynthesis models. The comparison of these results in different collision systems at different center-of-mass collision energies reveals a suppression of nucleus production in small systems. In the Statistical Hadronisation Model framework, this can be explained by a small correlation volume where the baryon number is conserved, as already shown in previous fluctuation analyses. However, a different size of the correlation volume is required to describe the proton yields in the same data sets. The coalescence model can describe this suppression by the fact that the wave functions of the nuclei are large and the fireball size starts to become comparable and even much smaller than the actual nucleus at low multiplicities