and hydrogen evolution reaction (HER) were deposited on Ni foam from low cost and abundant micro-sized particles of Ni(OH)2 and graphite powders using modified vaccum spray technique. The deposited thin films exhibited a mixed morphology of nanosheets and nanoflakes. We investigated the effect of increasing Ni(OH)2 content on the electrocatalytic activity toward the OER and the HER in 1 M KOH. We found that the hybrid catalyst with low Ni(OH)2 content (20 wt.%) revealed a high OER electrocatalytic activity that delivers 50 mA·cm-2 at an overpotential of 330 mV with a low Tafel slope of 78 mV·dec-1. Meanwhile, catalysts with higher Ni(OH)2 content (80 wt.%) exhibited superior HER activity that delivered 20 mA·cm-2 at an overpotential of 154 mV and a low Tafel slope of 92 mV·dec-1. The long term stability for both working electrodes was verified up to 25 hours

Nano-sized Co3O4–MoS2/Ni foam heterostructure electrodes were fabricated using a vacuum kinetic spray technique with microparticles of Co3O4 and MoS2. The deposited films were utilized to study the oxygen evolution reaction (OER) at various MoS2 contents (25, 50, 75 wt%). The surface state of the obtained heterostructure electrodes was characterized using various surfaces sensitive techniques such as scanning electron microscopy (SEM), Raman spectroscopy, and x-ray photoelectron spectroscopy (XPS). SEM images exhibited the fragmentation of the microparticles to smaller sizes in the nanoscale range. An analysis of the XPS spectra revealed the improvement in the cumulative synergy between the nanostructured Co3O4 and MoS2 in the heterostructured Co3O4–MoS2 electrocatalyst. We found that the gradual addition of MoS2 caused an enhancement in the OER activity due to improved charge transfer kinetics. Moreover, the heterostructure electrode with 75 wt% MoS2 showed the highest activity with the lowest OER overpotential value of 298 mV at 10 mA cm−2 and the smallest Tafel slope value of 46 mV·dec−1, as well as, 50 h OER stability at a current density of 50 mA cm−2.

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In the present study angular distributions of the differential cross section for elastic and inelastic scattering of alpha (α)-particles of 11В nuclei at different bombarding energies have been analyzed in the framework of the optical model (OM) potential. Two OM folding approaches were adopted in order to construct the real part of the α-nucleus potential. First, we generated the semi-microscopic single folding (SF) potential by folding an effective α-nucleon (α-N) interaction over the nuclear matter density of the target (11B) nucleus. In addition, the double folding (DF) approach was employed in order to deduce a microscopic representation of the optical potential by folding an effective density-dependent (DDM3Y) nucleon–nucleon interaction over the matter densities of the colliding nuclei. Successful theoretical predictions of six sets of experimental elastic scattering data have been obtained over the whole measured angular range. However, it was found that introducing real renormalization coefficients (~0.9–1.6) is essential in order to obtain best fits with data. On the other side, sixteen sets of the inelastic scattering data at several excited states of 11B nucleus were analyzed using the constructed SF and DF deformed potentials. In general, reasonable description of the data is obtained. However underestimated predictions of data were obtained at backward measured angles. The deduced reaction (absorption) cross sections and nuclear deformation lengths were also investigated.

In the present study angular distributions of the differential cross section for elastic and inelastic scattering of alpha (α)-particles of 11В nuclei at different bombarding energies have been analyzed in the framework of the optical model (OM) potential. Two OM folding approaches were adopted in order to construct the real part of the α-nucleus potential. First, we generated the semi-microscopic single folding (SF) potential by folding an effective α-nucleon (α-N) interaction over the nuclear matter density of the target (11B) nucleus. In addition, the double folding (DF) approach was employed in order to deduce a microscopic representation of the optical potential by folding an effective density-dependent (DDM3Y) nucleon–nucleon interaction over the matter densities of the colliding nuclei. Successful theoretical predictions of six sets of experimental elastic scattering data have been obtained over the whole measured angular range. However, it was found that introducing real renormalization coefficients (~0.9–1.6) is essential in order to obtain best fits with data. On the other side, sixteen sets of the inelastic scattering data at several excited states of 11B nucleus were analyzed using the constructed SF and DF deformed potentials. In general, reasonable description of the data is obtained. However underestimated predictions of data were obtained at backward measured angles. The deduced reaction (absorption) cross sections and nuclear deformation lengths were also investigated.

In the present study angular distributions of the differential cross section for elastic and inelastic scattering of alpha (α)-particles of 11В nuclei at different bombarding energies have been analyzed in the framework of the optical model (OM) potential. Two OM folding approaches were adopted in order to construct the real part of the α-nucleus potential. First, we generated the semi-microscopic single folding (SF) potential by folding an effective α-nucleon (α-N) interaction over the nuclear matter density of the target (11B) nucleus. In addition, the double folding (DF) approach was employed in order to deduce a microscopic representation of the optical potential by folding an effective density-dependent (DDM3Y) nucleon–nucleon interaction over the matter densities of the colliding nuclei. Successful theoretical predictions of six sets of experimental elastic scattering data have been obtained over the whole measured angular range. However, it was found that introducing real renormalization coefficients (~0.9–1.6) is essential in order to obtain best fits with data. On the other side, sixteen sets of the inelastic scattering data at several excited states of 11B nucleus were analyzed using the constructed SF and DF deformed potentials. In general, reasonable description of the data is obtained. However underestimated predictions of data were obtained at backward measured angles. The deduced reaction (absorption) cross sections and nuclear deformation lengths were also investigated.

An integrated technique of Gravity Recovery and Climate Experiment (GRACE) data along with other data-sets to estimate the variations of groundwater storage over Libya and its zones. Temporal (January 2003–December 2015) terrestrial water solutions (ΔTWS) of GRACE with outputs of Global Land Data Assimilation System (GLDAS) model were used. Findings are: (1) the Western Libya (zone 1), Eastern Libya (zone 2), and Northeastern Libya (zone 3) areas are receiving an average annual precipitation of 48, 30, and 154 mm/ yr, respectively, (2) the average GRACE-estimated groundwater storage variations (ΔGWS) were −4.13 ± 0.47 mm/yr, −3.36 ± 0.44, and +0.25 ± 0.14 mm/yr; however, the average annual extraction rates of −4.96 ± 0.50 mm/yr (−3.08 ± 0.31 km3/yr), −2.22 ± 0.22 mm/yr (−1.9 ± 0.19 km3/yr), and −0.31 ± 0.03 mm/yr (−0.042 ± 0.004 km3/yr) were from zones 1, 2, and 3, respectively, (3) the observed depletion in groundwater of zones 1, and 2 is largely related to the prevailed dry conditions over these zones and the heavy anthropogenic effects, (4) the minor recharge of 0.83 ± 0.69 mm/yr (0.52 ± 0.43 km3/yr) is happening over zone 1 from the surrounding highlands and from the rainfall over the northern coastal areas, and is compensating for part of the groundwater withdrawal, (5) the groundwater in zone 2 is partially flowing northeastward to the Dakhla basin along the preferred groundwater flow conduit of the Pelusium megashear system, and partially flowing northward to the Mediterranean Sea, (6) zone 3 is receiving a minor recharge of 0.56 ± 0.14 mm/yr (0.077 ± 0.02 km3/yr), and (7) a progressive increase in Cl-36 groundwater ages supports the groundwater flow directions along structures that are sub-parallel to the flow direction. The integrated technique provides a practical and informative study.

The North Africa region is seeking water resources to develop agricultural expansions and land reclamation projects based on the groundwater resources. Monthly (April 2002–July 2016) terrestrial water storage (TWS) solutions of the Gravity Recovery and Climate Experiment (GRACE) along with other datasets were used to monitor and estimate the variations in groundwater storage over the Sudanese area and its sections. Results indicate: (1) the Sudanese area, Southern Sudan and Northern Sudan sections are receiving an average recharge of +4.15 ± 1.07, +2.46 ± 1.69, and +4.74 ± 0.76 mm/yr, respectively during the analysed period, taking into an account the annual extraction rate of 0.67 ± 0.067, 1.04 ± 0.104 and 0.54 ± 0.054 mm/yr from the Sudanese area, Southern Sudan and Northern Sudan sections, respectively, (2) and the average groundwater storage variations of +3.35 ± 1.07, +1.21 ± 1.69 and +4.09 ± 0.76 mm/yr from the Sudanese area, Southern Sudan and Northern Sudan sections, respectively, and (3) the assumed natural discharge of −0.13 ± 0.013, −0.21 ± 0.021, and −0.11 ± 0.011 mm/yr from the Sudanese area, Southern Sudan and Northern Sudan sections, respectively. (4) The average precipitation of Tropical Rainfall Measuring Mission data over the Sudanese area, Southern Sudan and Northern Sudan sections was estimated at 520.2, 1165.6 and 300.3 km3/yr, respectively. (5) The ground surface relief is forming northeastward streams taking the surface water away to the river. (6) The groundwater flows to the southernmost part of Egypt is impeded by the Uweinat-Aswan basement uplift and the thinned sedimentary cover in northern Sudan and southern Egypt, which in turn flows northeastward to the river. (7) The integrated study is informative and cost-effective model for best estimating the recharge rate of large areas.

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This article reviews the various hole transporting materials (HTMs) used in perovskite solar cells (PSCs) in achieving high photo-conversion efficiency (PCE) and operational stability. The PSCs are the latest development in solution processable solar cells offering PCE (~22%) on a par with that of practically deployed silicon and thin film solar cells. HTMs and electron transporting materials (ETMs) are important constituents in PSCs as they selectively transport charges within the device, influence photovoltaic parameters, determine device stability and also influence its cost. This article critically approaches role of structure, electrochemistry, and physical properties of varied of choice of HTMs categorized diversely as small and long polymers, organometallic, and inorganic on the photovoltaic parameters of PSCs conceived in various device configurations. Achievements in tailoring the properties of HTMs to best fit for PSCs are detailed; a well-designed HTM suppresses carrier recombination by facilitating the passage of holes but blocking electrons at the HTM/perovskite interface. Moreover, in many PSCs the HTM acts as the first line of defense to external degrading factors such as humidity, oxygen and photon dose, the extent of which depends on its hydrophobicity, permeability, and density.