Experimental high-dimensional two-photon entanglement and violations of generalised Bell inequalities

Quantum entanglement plays a vital role in many quantum information and communication tasks. Entangled states of higher dimensional systems are of great interest due to the extended possibilities they provide. For example, they allow the realisation of new types of quantum information schemes that can offer higher information-density coding and greater resilience to errors than can be achieved with entangled two-dimensional systems. Closing the detection loophole in Bell test experiments is also more experimentally feasible when higher dimensional entangled systems are used. We have measured previously untested correlations between two photons to experimentally demonstrate high-dimensional entangled states. We obtain violations of Bell-type inequalities generalised to d-dimensional systems with up to d = 12. Furthermore, the violations are strong enough to indicate genuine 11-dimensional entanglement. Our experiments use photons entangled in orbital angular momentum (OAM), generated through spontaneous parametric down-conversion (SPDC), and manipulated using computer controlled holograms

Z-Selective Hydrofunctionalization of Dienes

Olefins play a fundamental role in synthetic organic chemistry because they are useful building blocks that create molecules. However, geometry control (E- vs Z-) in olefin synthesis is of utmost importance because the olefin geometry has a tremendous impact on its physical, chemical and biological properties. Additionally, Z-olefins are less stable compared to their E-olefin counterparts; due to this difference, general methods to make olefins results in more cases of E-olefins production with relatively fewer Z-olefins caused by its instability. It has been reported that Z-olefins can be synthesized from dienes through a rhodium-catalyzed formate mediated transformation, with tolerance to several reducible functional groups.  With this successful method in hand, the focus is to make functionalized Z-alkenes while still maintaining tolerance to reducible functional groups under mild reaction conditions. Thus, this project presents the production of Z-olefins through rhodium-catalyzed hydrofunctionalization using the starting materials, dienes and aldehydes. This method requires an inert atmosphere and the reaction progress can be monitored by Nuclear Magnetic Resonance (NMR) using an internal standard to quantify the amount of product formed. In this process, it was observed that the starting material was consumed until more than 95% conversion. In addition, the possibility of using different dienes, such as diene esters and phenyl dienes, as well as different aldehydes could further broaden the scope of this method. The usefulness of this process can be applied to the production of complex molecules. For example, in the synthesis of a glucagon receptor antagonist, which is a drug that is used in the treatment of diabetes. Currently, there is a limited number of methods used to create Z-olefins; however, this proven procedure can be further implicated in other hydrofunctionalization experiments

The role of octadecanoids and functional mimics in soybean defense responses

Oxylipins of the jasmonate pathway and synthetic functional analogs have been analyzed for their elicitor like activities in an assay based on the induced accumulation of glyceollins, the phytoalexins of soybean (Glycine max L.), in cell suspension cultures of this plant. Jasmonic acid (JA) and its methyl ester showed weak phytoalexininducing activity when compared to an early jasmonate biosynthetic precursor, 12-oxophytodienoic acid (OPDA), as well as to the bacterial phytotoxin coronatine and certain 6-substituted indanoylLisoleucine methyl esters, which all were highly active. Interestingly, different octadecanoids and indanoyl conjugates induced the accumulation of transcripts of various defenserelated genes to different degrees, indicating distinct induction competencies. Therefore, these signaling compounds and mimics were further analyzed for their effects on signal transduction elements, such as the transient enhancement of the cytosolic Ca2+ concentration and MAP kinase activation, which are known to be initiated by a soybean pathogenderived {[}beta]glucan elicitor. In contrast to the {[}beta]glucan elicitor, none of the other compounds tested triggered these early signaling elements. Moreover, endogenous levels of OPDA and JA in soybean cells were shown to be unaffected after treatment with {[}beta]glucans. Thus, OPDA and JA, which are functionally mimicked by coronatine and a variety of 6-substituted derivatives of indanoylLisoleucine methyl ester, represent highly efficient signaling compounds of a lipidbased pathway not deployed in the {[}beta]glucan elicitorinitiated signal transduction

Tropospheric delay in microwave propagation in Nigeria

Satellite communication systems suffer from the systematic error of tropospheric delay. Accurate estimation of this delay is essential for communication budget and planning. This study investigates the tropospheric delay in three Nigeria cities: Abuja, Lagos, Port-Harcourt using two different models (Saastominen and Hopfield). Three year atmospheric data for surface pressure, relative humidity and temperature obtained at 5-mins interval were acquired from the Tropospheric Data Acquisition Network (TRODAN) archives. Computed radio refractivity values showed distinct seasonal dependence in Abuja with low and high values during the dry and wet season respectively. The Hopfield model predicts higher hydrostatic delay values than the Saastominen model. In the non-hydrostatic delay, the two models converge to a single values at high temperature. Theorems were proposed with proofs to explain the relationship observed between the two models

WATER USE EFFICIENCY OF OKRA AMENDED WITH SAW-DUST UNDER DEFICIT IRRIGATION IN A CONTROLLED ENVIRONMENT

Enormous funds are spent annually on providing moisture for crop use throughout each planting cycle. The sharp depletion of moisture available for planting necessitates essential amendment measures, keenly focused on moisture conservation. A research trial consisiting of an experimental design of 12 samples arranged in a specific order to meet the research requirement. Treatment samples of soil–sawdust were mixed proportionally at (25%-75%, 50%-50%, 75%-25%, 100%-0%) with varying water application of (100%, 50% and 25%). Growth stages amongst samples were visible owing to variance in height and yield. The amended samples greatly conserved moisture through a wide margin by the difference in bucket weight. Rates of moisture conservation in amended samples correspondingly declined with a descending sawdust application; samples with greater sawdust application showed higher moisture conservation. The growth and yield of the amended samples to the leave-alone samples greatly varied. The leave-alone samples proved to be less moisture conservative, but showing high- moisture usage potential&nbsp

Evaluation of different irrigation methods in Chanchaga irrigation scheme, north central Nigeria

This study was aimed at evaluating different methods of irrigation based on parametric evaluation method for Chanchaga irrigation  scheme, Nigeria. Soil samples were collected at various rooting depths of 0-15 cm, 15-40 cm and 40-75 cm, the collected samples were  analysed for physical properties. Various suitability classes were generated for surface, sprinkler and drip irrigation methods using the capability index. The results revealed that the use of drip irrigation system for soil depths of 0-15 cm and 15 -40 cm within the study area were found to be suitable and not suitable for deep rooted areas of 40-75 cm. The sprinkler irrigation method was found to be suitable for study locations 3 and 4 at depths of 15-40 cm. At depths 40-75 cm, drip irrigation method was found suitable for locations 1, 2 and 5 while locations 3 and 4 supports the use of sprinkler irrigation method. It is therefore concluded that the sprinkler and drip irrigation methods are both highly favoured for irrigation purpose in the Chanchaga irrigation scheme

EFFECT OF TILLAGE METHODS ON SOIL PHYSICAL AND STRENGTH PROPERTIES UNDER AMARANTHUS HYBRIDUS PRODUCTION IN A SANDY-LOAM ENVIRONMENT

Amaranthus hybridus (African Spinach) production is a common vegetable in many southwestern parts of Nigeria. Many farmers grow it for its high source of protein and vitamins under different soil conditions without taking into consideration the tillage method that best gives the highest yield. A field study was conducted on a sandy loam soil in the National Centre for Agricultural Mechanization, Ilorin. Nigeria during the raining season of 2017 to investigate the effect of tillage methods on soil physical properties, penetration resistance and shear strength under Amaranthus hybridus production. The experiment was a completely randomized design with three replications. Tillage methods were disc plough (DP), disc harrow (DH), combination of disc plough and disc harrowing (DPH) and zero tillage (ZT). Soil physical parameters investigated during the growth stages of the crop were soil bulk density, soil moisture content, penetration resistance, shear stress and total porosity. Average bulk density for DP, DPH, DH and ZT were 1.33, 1.30, 1.25 and 1.50 g/cm3 respectively. Shear stress increased with depth in all the plots. Maximum values at the 14-21 cm depth were 132, 104, 166 and 16 mPa for DP, DPH, DH and ZT respectively. The average penetration resistance on the DP, DPH, DH and ZT at the 14-21cm depth were 84.3, 82, 178 and 97 kPa respectively. Amaranthus hybridus yield was highest on the DPH plots with an average weight of 10 stands weighing 108g.  Disc ploughed + harrowing was the best tillage practice considering the soil physical properties, penetration resistance and shear stress of the plots for the optimum yield of Amaranthus hybridus on the sandy loam field

Information Security in Health Care Centre Using Cryptography and Steganography

As the volume of medicinal information stored electronically increase, so do the need to enhance how it is secured. The inaccessibility to patient record at the ideal time can prompt death toll and also well degrade the level of health care services rendered by the medicinal professionals. Criminal assaults in social insurance have expanded by 125% since 2010 and are now the leading cause of medical data breaches. This study therefore presents the combination of 3DES and LSB to improve security measure applied on medical data. Java programming language was used to develop a simulation program for the experiment. The result shows medical data can be stored, shared, and managed in a reliable and secure manner using the combined model.Comment: 13 pages, 10 figures, 1 tabl

Screening nuclear field fluctuations in quantum dots for indistinguishable photon generation

A semiconductor quantum dot can generate highly coherent and indistinguishable single photons. However, intrinsic semiconductor dephasing mechanisms can reduce the visibility of two-photon interference. For an electron in a quantum dot, a fundamental dephasing process is the hyperfine interaction with the nuclear spin bath. Here we directly probe the consequence of the fluctuating nuclear spins on the elastic and inelastic scattered photon spectra from a resident electron in a single dot. We find the nuclear spin fluctuations lead to detuned Raman scattered photons which are distinguishable from both the elastic and incoherent components of the resonance fluorescence. This significantly reduces two-photon interference visibility. However, we demonstrate successful screening of the nuclear spin noise which enables the generation of coherent single photons that exhibit high visibility two-photon interference.Comment: 5 pages, 4 figures + Supplementary Informatio