Quantum key distribution (QKD) provides unconditional security in theory. However, practical QKD systems face challenges in maximizing the secure key rate and extending transmission distances. In this paper, we introduce a comparative study of the BB84 protocol using coincidence detection with two different quantum channels: a free space and underwater quantum channels. A simulated seawater was used as an example for underwater quantum channel. Different single photon detection modules were used on Bob’s side to capture the coincidence counts. Results showed that increasing the mean photon number generally leads to a higher rate of coincidence detection and therefore higher possibility of increasing the secure key rate. The secure key rate can reach 0.0239 (bits/pulse) with a quantum bit error rate (QBER) of 3.2% for the free space channel and 1.5% for the simulated sea-water channel. The security parameters for each value of the mean photon number closely align with the corresponding theoretical predictions. However, some discrepancies were observed, primarily due to a mismatch in photon detection efficiency for SPDMs and system fluctuations. The theoretical calculations also predict that using coincidence detection, the key can be distributed over distances of up to 195 km.
Used vegetable oil was introduced to transesterfication reaction to produce Biodiesel fuel suitable for diesel engines. Method of production was consisted of filtration, transesterfication, separation and washing. Transesterfication was studied extensively with different operating conditions, temperature range (35-80o C), catalyst concentration (0.5-2 wt. % based on oil), mixing time (30-120 min.) with constant oil/methanol weight ratio 5:1 and mixing speed 1300 rpm. The concentration of Fatty acid methyl esters (Biodiesel) was determined for the transesterficated oil samples, besides of some important physical properties such as specific gravity, viscosity, pour point and flash point. The behavior of methyl esters production and the
... Show MoreElectronic Alattarh been studied long flexible factors forming the nucleus of boron in the shell model framework multipolar been identified factors was introduced into the effects of polarization heart in the first place accounts
Used vegetable oil was introduced to transesterfication reaction to produce Biodiesel fuel suitable for diesel engines. Method of production was consisted of filtration, transesterfication, separation and washing. Transesterfication was studied extensively with different operating conditions, temperature range (35-80oC), catalyst concentration (0.5-2 wt. % based on oil), mixing time (30-120 min.) with constant oil/methanol weight ratio 5:1 and mixing speed 1300 rpm. The concentration of Fatty acid methyl esters (Biodiesel) was determined for the transesterficated oil samples, besides of some important physical properties such as specific gravity, viscosity, pour point and flash point. The behavior of methyl esters production and the physica
... Show MoreThe study included the determination of pollen grains features for 8 genera and 13 taxa of Mimosoideae subfamily grown in Baghdad/ Iraq by using each of light and scanning electron microscope. The samples of taxa were collected from various sites in Baghdad province in central Iraq located on 32 45° 0-33 45 0 N and 44 0 0- 44° 45 0 E. the results from this study revealed different pollen types as monad in each of Leucaena, Prosopis, and Neltuma, tetrad in Mimosa and polyads in Acacia, Albizia, Calliandra, Pithecellobium and Vachellia. Each taxa of these genera characterized by special palynological features as shape, size, number of polyads grain and conplateuration as well as other parameters included other dimensions, and these
... Show MorePurpose/objective:
1 - To explain the financial impact of the activities and areas of human resources management and the adoption of the methodology for estimating costs on the basis of conduct and statement of how to assess costs and benefits of human resource activities.
2 - Measuring human capital, and its impact on the financial statements.
Design/methodology/approach:
Concentrated dimensions of the research paper's lack of financial statements prepared by the organizations for information mandated human resource its components of the three (attraction - development
... Show MoreThe interest in calcium phosphates arises from the fact that bones contain a high percentage of mineralized calcium phosphate . In this study, pure and biocompatible hydroxyapatite (HAP) powder was successfully synthesized using hen’s egg shell as calcium source and phosphoric acid by precipitation method.The precipitate obtained was subjected to ripenning process for 24 hours, filtered, air dried, and calcined at temperatures of 400,800,900,and 1000 ºC.
X-Ray diffraction(XRD) technique was used to investigate the formation of HAP powder, XRD results revealed the HAP formation and also indicate no occurrence of secondary phases. Fourier Transform Infrared(FT-IR) spectrum shows the characterstic peaks for phosphate and hydroxyl grou
