The Effect of Adding Steel Fibers and Graphite on Mechanical and Electrical Behaviors of Asphalt Concrete

Conductive asphalt concrete can satisfy different and multifunctional applications such as heating roads to get rid of snow and ice and assure auto-detection, auto-cure, and energy recovery. This research aims to evaluate the performance of asphalt concrete with additives like steel fibers and graphite powder. This work is based on destructive tests (direct tensile test FENIX) and non-destructive tests (electrical resistivity measures). The obtained results indicate that the tensile resistance, dissipated energy, and ductility module of asphalt concrete increased with the increasing steel fiber percentage. Direct tensile strength, cracking resistance, and dissipated energy increased as graphite percentage increased, while the ductility module decreased. Electrical resistivity decreased when it added steel fibers and graphite. Therefore, it found that tensile strength increased reversibly with electrical resistance. When adding steel fibers or graphite powder, the dissipated energy of asphalt concrete is increased while electrical resistivity is decreased. The dissipated energy of conductive asphalt concrete with steel fibers is higher than that with graphite powder. Electrical resistivity decreased significantly with increasing steel fibers, compared to electrical resistivity with graphite. The obtained results indicate that asphalt concrete cracking resistance is higher with the optimal percentage of steel fibers added at 1% and better mechanical performance. Doi: 10.28991/CEJ-2022-08-02-012 Full Text: PD

Bipolar versus fixed-head hip arthroplasty for femoral neck fractures in elderly patients

Between 2002 and 2007, fifty elderly patients with displaced femoral neck fractures were treated with hip replacement at Emergency Hospital, Mansoura University. Patients were randomly selected, 25 patients had either cemented or cementless bipolar prosthesis, and another 25 patients had either cemented or cementless fixed-head prosthesis. There were 34 women and 16 men with an average age of 63.5 years (range between 55 and 72 years). All patients were followed up both clinically and radiologically for an average 4.4 years (range between 2 and 6 years). At the final follow-up, the average Harris hip score among the bipolar group was 92 points (range between 72 and 97 points), while the fixed-head group was 84 points (range between 65 and 95 points). Radiologically, joint space narrowing more than 2 mm was found in only 8% (2 patients) among the bipolar group, and in 28% (7 patients) of the fixed-head group. Through the follow-up period, total hip replacement was needed in two cases of the bipolar group and seven cases of the fixed-head group. Bipolar hemiarthroplasty offered a better range of movement with less pain and more stability than the fixed-head hemiarthroplasty in elderly patients with displaced femoral neck fractures

Enhanced Parallel Hash Function Algorithm Based on 3C Construction (EPHFA-3C)

The hash function is a function that can convert data from variable size to fixed-size data that can be used in security of communication like, authentication, digital signature and integration. In this paper, a parallel, secure and fast hash function algorithm that is based on 3C construction is proposed. It is an enhancement for the MD construction. This enhancement makes the construction more resistant to the extension and multi-blocks attacks. The parallel structure of the algorithm improves the speed of hashing and reduces the number of operations. The simulation analysis such as hashes distribution, confusion and diffusion properties, and collision resistance are executed. Based on the results, our proposed hash algorithm is efficient, simple, and has strong security compared with some recent hash algorithms

EFFECT OF BIODEGRADABLE CO-POLYMERS AND DIVALENT CATIONS ON THE SUSTAINED RELEASE ABILITY OF PROPRANOLOL HYDROCHLORIDE LOADED BIOMATERIAL MICROSPHERES

Objective: Propranolol Hydrochloride (PHCL) is used for the treatment of hypertension and angina pectoris; however it has two major problems; short biological halfâ€life and low bioavailability, so the aim of the present work was to develop PHCL mucoadhesive microsphere to prolong the residence time at the absorption site, therefore, increase the bioavailability.Methods: PHCL microspheres were prepared by ionotropic gelation method using nature polymers. Factorial design (33) was used to develop PHCL mucoadhesive microspheres, the independent factors used were polymer type (Sodium carboxymethyl cellulose (Na CMC), and Hydroxyl propyl methyl cellulose (HPMC), Carpobol 940), cross-linking type (calcium chloride, zinc chloride and barium chloride) and the concentration of Chitosan (0.5, 1, 1.5 %w/v). The developed microspheres were physicochemical characterized. The selected formula was selected for mucoadhesive test and in vivo study on human volunteers.Results: The results revealed that the PHCL mucoadhesive microspheres have good flowability, the mean particle sizes ranged from 541 to 815 µm and the entrapment efficiency ranged from 35.6% to 69.53%. The selected PHCL microspheres showed spherical particles with a rough surface and exhibited a slow release over 8h. The pharmacokinetic data of selected PHCL microspheres showed prolonged Tmax, decreased Cmax and AUC0–∞ value of 926.21±40.74ng. h/ml indicating improved relative bioavailability by144.93% compared with marketed tablets.Conclusion: PHCL microspheres were successfully prepared by ionic gelatin method that retards the release and enhances the oral bioavailability.Keywords: Propranolol HCL, Microspheres, Ionic gelation method, Chitosan, Relative bioavailabilit

The value of a comparative approach with equine vaccine development for the development of human influenza DNA vaccines

Abstract: A comparative medicine approach, whereby similarities and differences in biology between human and veterinary species are used to enhance understanding for the benefit of both, is highly relevant to the development of viral vaccines. Human and equine influenza share many similarities in pathogenesis and immune responses. The DNA vaccine approach offers potential advantages for responding rapidly and effectively to outbreaks or pandemics in both humans and animals, especially in under-resourced regions. The European and American vaccine regulatory authorities require demonstration of vaccine efficacy in animal models. However, mice, the most widely used model, are not naturally infected with influenza viruses, resulting in different pathobiology. Additionally, mice as a model for DNA vaccine testing appear to overestimate the humoral immune response compared to other mammalian species. In this review, we propose that testing of DNA vaccines against influenza type A viruses (and other shared pathogens) in the horse can provide valuable knowledge for the development of human DNA vaccines

On the Optimization of the Species Separation in an Inclined Darcy-Brinkman Porous Cavity under the Effect of an External Magnetic Field

An investigation is conducted to study analytically and numerically the effect of a magnetic field on the species separation induced by the combined effects of convection and Soret phenomenon in an inclined porous cavity saturated by an electrically conductive binary mixture and provided with four impermeable walls. The long sides of the cavity are subject to uniform heat flux while its short ends are adiabatic. Uniform magnetic field is applied perpendicularly to the heated walls. The mixture satisfies the Boussinesq approximation and the porous medium, modeled according to Darcy-Brinkman’s law, is assumed homogeneous and isotropic .The relevant parameters for the problem are the thermal Rayleigh number (RT = 1 to 106), the Lewis number (Le = 10), the inclination angle of the cavity (θ = 0º to 180), the separation parameter (φ = 0.5), the Darcy number (Da = 10-5 to 103), the Hartmann number (Ha = 0 to 100) and the aspect ratio of the cavity (Ar = 12). The limiting cases (Darcy and pure fluid media) are recovered in this study. Optimum conditions leading to maximum separation of species are determined while varying the governing parameters in their respective ranges. Results show that the magnetic field can enhance the species separation in cases where the optimal coupling between thermosolutal diffusion and convection is not achieved in its absence. On the other hand, in cases where this optimal coupling is reached in the absence of the magnetic field, the application of the latter destroys the separation of species

On MILP-Based Automatic Search for Differential Trails Through Modular Additions with Application to Bel-T

Using modular addition as a source of nonlinearity is frequently used in many symmetric-key structures such as ARX and Lai--Massey schemes. At FSE\u2716, Fu \etal proposed a Mixed Integer Linear Programming (MILP)-based method to handle the propagation of differential trails through modular additions assuming that the two inputs to the modular addition and the consecutive rounds are independent. However, this assumption does not necessarily hold. In this paper, we study the propagation of the XOR difference through the modular addition at the bit level and show the effect of the carry bit. Then, we propose a more accurate MILP model to describe the differential propagation through the modular addition taking into account the dependency between the consecutive modular additions. The proposed MILP model is utilized to launch a differential attack against Bel-T-256, which is a member of the Bel-T block cipher family that has been adopted recently as a national standard of the Republic of Belarus. In particular, we employ the concept of partial Differential Distribution Table to model the 8-bit S-Box of Bel-T using a MILP approach in order to automate finding a differential characteristic of the cipher. Then, we present a $4\frac{1}{7}$-round (out of 8) differential attack which utilizes a $3$-round differential characteristic that holds with probability $2^{-111}$. The data, time and memory complexities of the attack are $2^{114}$ chosen plaintexts, $2^{237.14}$ $4\frac{1}{7}$-round encryptions, and $2^{224}$ 128-bit blocks, respectively

A Meet-in-the-Middle Attack on Reduced-Round Kalyna-b/2b

Kalyna is an SPN-based block cipher that was selected during Ukrainian national public cryptographic competition (2007-2010), and its slight modification was approved as the new encryption standard of Ukraine (DSTU 7624:2014) in 2015. The cipher supports a block size and a key length of 128, 256 and 512 bits where the size of the key can be either double or equal to that of the block length. According to its designers, the cipher provides strength to several cryptanalytic methods after the fifth and sixth rounds of the 128-bit and 256-bit block versions, respectively. In this paper, we present a meet-in-the-middle attack on the 7-round reduced versions of Kalyna where the key size is double the block length. Our attack is based on the differential enumeration approach where we carefully deploy a four round distinguisher in the first four rounds to bypass the effect of the carry bits resulting from the pre-whitening modular key addition. We also exploit the linear relation between consecutive odd and even indexed round keys which enables us to attack seven rounds and recover all the round keys incrementally. The attack on Kalyna with 128-bit block has a data complexity of $2^{89}$ chosen plaintexts, time complexity of $2^{230.2}$ and a memory complexity of $2^{202.64}$. The data, time and memory complexities of our attack on Kalyna with 256-bit block are $2^{233}$, $2^{502.2}$ and $2^{170}$, respectively