Deployment of drone-based small cells for public safety communication system

In the event of a natural disaster, communications infrastructure plays an important role in organizing effective rescue services. However, the infrastructure-based communications are often affected during severe disaster events such as earthquakes, landslides, floods, and storm surges. Addressing this issue, the article proposes a novel drone-based cellular infrastructure to revive necessary communications for out-of-coverage user equipment (UE) which is in the disaster area. In particular, a matching game algorithm is proposed using one-to-many approach wherein several drone small cells (DSCs) are deployed to match different UEs to reach a stable connection with optimal throughput. In addition, a medium access control framework is then developed to optimize emergency and high priority communications initiated from the rescue workers and vulnerable individuals. The simulation results show that the throughput for the out-of-coverage UEs are significantly improved when the DSCs are deployed in public safety network while the channel access delay is also notably reduced for emergency communications within the affected areas

Di-tert-Butyl 2,2′-[2,2′-methyl­enebis(naphthalene-2,1-diyldi­oxy)]diacetate

In the title compound, C33H36O6, two naphthalene ring systems are connected through a methyl­ene linkage [C—C—C = 114.9 (2)°]; the ring systems are aligned at an angle of 76.5 (1)°. Of the two –O–CH2–C(=O)–C(CH3)3 substituents, one adopts an extended conformation whereas the other is U-shaped. In the crystal, mol­ecules are linked via weak C—H⋯O hydrogen bonding, forming supra­molecular chains running along the c axis

Bis[5-chloro-2-(prop-2-yn-1-yl­oxy)phen­yl]methane

The mol­ecule of the title compound, C19H14Cl2O2, has two benzene rings connected to a methyl­ene C atom, and the rings are aligned at 66.3 (1)°. Inter­molecular C—H⋯π and π–π stacking inter­actions are observed in the crystal structure, the centroid–centroid distances between parallel benzene rings being 3.7529 (12) and 3.6201 (12) Å, respectively

tert-Butyl 2-(4-nitro­phen­oxy)acetate

In the title mol­ecule, C12H15NO5, the nitro­phen­oxy portion is approximately planar (r.m.s. deviation = 0.034 Å) and makes an angle of 84.8 (1)° with respect to the –CH2–C(=O)–O–C fragment. In the crystal, π–π stacking is observed between nearly parallel benzene rings of adjacent mol­ecules, the centroid–centroid distance being 3.6806 (10) Å. Weak inter­molecular C—H⋯O hydrogen bonding is present in the crystal structure

1,4-Bis{4-[bis­(prop-2-yn-1-yl)amino]­phen­oxy}benzene

The asymmetric unit of the title compound, C30H24N2O2, contains two independent mol­ecules, which both lie on centers of inversion. The central phenyl­ene ring is inclined at 61.4 (2)° with respect to the flanking aromatic ring [dihedral angle = 70.7 (3)° in the second mol­ecule]

A framework for the analysis of determinants of social media acceptance in higher educational institute of Pakistan

Social media is being considered an important source in the perspective of academic learning in the educational sector.The scope of learning through social media encompasses broadening the information sharing through collaborative approach with the help of web-based social networking sites as the means to enhance the knowledge of coworkers, colleagues and other mates.Due to large scale penetration of social media among youngsters, it is being perceived to be one of the futuristic approaches for next generation knowledge sharing and academic learning.On one hand, learning through social media has attained an important value in developed economies but on the other hand, real benefits and future implications have not been interpreted and realized in developing economies like Pakistan.Educational institutes in Pakistan need to evaluate and understand the importance and the usage of social networking for the sake of its valued role in academia.Although research communities in the developing countries are paying attention towards the development of this sector in academia but Pakistan still has to go a long way in this regard.The aim of the study is to explore the significant factors which are affecting the delayed acceptance and usage of social media for academic learning purpose.This research proposes an integrated framework including some widely accepted technology models such as Technology Acceptance Model (TAM) and Innovation Diffusion Theory (IDT) to determine significant factors

4-Bromo-1-nitro­benzene

The non-H atoms of the title mol­ecule, C6H4BrNO2, are essentially coplanar with an r.m.s. deviation of 0.040 Å. In the crystal, π–π stacking occurs between parallel benzene rings of adjacent mol­ecules with centroid–centroid distances of 3.643 (3) and 3.741 (3) Å. Weak inter­molecular C—H⋯O hydrogen bonding and short Br⋯O contacts [3.227 (4) 3.401 (4) Å] are also observed in the crystal structure. The crystal studied was a non-morohedral twin with a 26.1 (6)% minor component

Biochar affects growth and biochemical activities of fenugreek (Trigonella corniculata) in cadmium polluted soil

Cadmium (Cd) has no defined biological role and may enter the food chain from polluted soils. Biochar has been proposed as an organic amendment to minimize the toxic effects of Cd for plants grown on contaminated soils. In this study, biometric and biochemical attributes of fenugreek (Trigonella corniculata) grown on artificially cadmium (Cd) contaminated soil (0, 25, 50, 75 and 100 mg Cd/kg soil) at three levels of cotton-sticks derived biochar (CSB; 0, 3 and 5 %) were studied. Data show significant decline in the growth, photosynthetic pigments (chlorophyll a, b and total, carotenoids, anthocyanin and lycopene), and physiological attributes (sub-stomatal CO2 concentrations, photosynthetic and transpiration rate) in the presence of high Cd concentrations (50 and 100 mg Cd/kg soil). However, the decline was reduced in the presence of CSB. A steady amplification in lipid peroxidation (assessed via Malondialdihyde (MDA)) and ascorbic-acid assembly was noted with increasing Cd. The concentration of Cd in the root and shoot also decreased with increasing CSB application rates from 3 % - 5 %.Overall, the greater production of protein, amino acids and sugar contents in response to higher application rates of CSB seems to be due to alleviation in Cd toxicity. Thus, cotton-sticks can be safely utilized in the form of biochar as amendment with additional benefit of reducing Cd bioavailability and toxicity to crop plants

n-Undeca­nyl 2-(4-chloro­anilino)-4,4-dimethyl-6-oxocyclo­hex-1-ene­carbo­dithio­ate

The six-membered cyclo­hexene ring in the title compound, C26H38ClNOS2, adopts an envelope conformation, with the C atom bearing the two methyl groups representing the flap. This atom deviates by 0.642 (4) Å from the plane passing through the other five atoms of the ring (r.m.s. deviation = 0.053 Å). The mol­ecular conformation is stabilized by an intra­molecular N—H⋯S hydrogen bond