Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 13 de 13
Filter
Add more filters










Publication year range
1.
PLoS One ; 19(1): e0294429, 2024.
Article in English | MEDLINE | ID: mdl-38289970

ABSTRACT

Cloud computing is vital in various applications, such as healthcare, transportation, governance, and mobile computing. When using a public cloud server, it is mandatory to be secured from all known threats because a minor attacker's disturbance severely threatens the whole system. A public cloud server is posed with numerous threats; an adversary can easily enter the server to access sensitive information, especially for the healthcare industry, which offers services to patients, researchers, labs, and hospitals in a flexible way with minimal operational costs. It is challenging to make it a reliable system and ensure the privacy and security of a cloud-enabled healthcare system. In this regard, numerous security mechanisms have been proposed in past decades. These protocols either suffer from replay attacks, are completed in three to four round trips or have maximum computation, which means the security doesn't balance with performance. Thus, this work uses a fuzzy extractor method to propose a robust security method for a cloud-enabled healthcare system based on Elliptic Curve Cryptography (ECC). The proposed scheme's security analysis has been examined formally with BAN logic, ROM and ProVerif and informally using pragmatic illustration and different attacks' discussions. The proposed security mechanism is analyzed in terms of communication and computation costs. Upon comparing the proposed protocol with prior work, it has been demonstrated that our scheme is 33.91% better in communication costs and 35.39% superior to its competitors in computation costs.


Subject(s)
Confidentiality , Telemedicine , Humans , Computer Security , Delivery of Health Care , Privacy
2.
Sci Rep ; 13(1): 16934, 2023 Oct 07.
Article in English | MEDLINE | ID: mdl-37805636

ABSTRACT

The aim of present work is to apply the Caputo-Fabrizio fractional derivative in the constitutive equations of heat transfer. Natural convection flow of an unsteady second grade fluid over a vertical plate with exponential heating is discussed. The generalized Fourier law is substituted in temperature profile. A portion of the dimensionless factors are utilized to make the governing equations into dimensionless structures. The solutions for temperature and velocity profiles of Caputo-Fabrizio model are acquired through the Laplace transform method. These solutions are greatly affected through the variation of different dimensionless variables like Prandtl number, Grashof number, and second-grade fluid parameter. Finally, the influence of embedded parameters is shown by plotting graphs through Mathcad. From the graphical results it is concluded that, the temperature of the fluid decreases with the increasing values of the Prandtl number and Second grade fluid parameter and increases with the passage of time. The velocity of the fluid increases with increasing values of the Grashof number, second grade parameter and time while decreases with increasing values of fractional parameter and Prandtl number.

3.
Nanotechnology ; 34(46)2023 Aug 29.
Article in English | MEDLINE | ID: mdl-37549667

ABSTRACT

The present article describes the impact of variable thermal conductivity on the flow of ternary hybrid nanofluid with cylindrical shape nanoparticles over a stretching surface. Three nanoparticles combine in base fluid polymer. The assumption made will be used to model an equations. Modeled equations are in the form of a system of partial differential equations are difficult to solve can be converted to system of an ordinary differential equations, through resemblance substitutions, and will be solved numerically. Numerical scheme of Runge-Kutta order four is coupled with the shooting method to solve the resulting equations. The graphs in the study illustrate how physical quantities, such as magnetic field, injection/suction, nanoparticles volume fraction, and variable thermal conductivity, affected the velocity, skin friction, temperature, and local Nusselt number. The velocity profiles deflate as the volume fraction rises. While the temperature rises with an increase in the volume fraction of nanoparticles for both injection and suction, the velocity profiles also decline as the injection and suction parameter increases. Furthermore, as the magnetic field increases, the temperature profile rises while the velocity profile falls. The temperature curves increase as thermal conductivity increases. Finally, as the magnetic field is strengthened, the Nusselt number and skin friction decrease. The combination of mathematical modeling, numerical solution techniques, and the analysis of physical quantities contributes to the advancement of knowledge in this ternary hybrid nanofluid.

4.
Sci Rep ; 13(1): 5220, 2023 Mar 30.
Article in English | MEDLINE | ID: mdl-36997528

ABSTRACT

The aim of the present work is to apply the Caputo-Fabrizio fractional derivative to the heat transformation of unsteady incompressible second grade fluid. The effects of magneto hydro dynamic and radiation are analyzed. In governing equation of heat transfer nonlinear radiative heat is examined. Exponential heating phenomena is considered at boundary. Firstly, the dimensional governing equations with the initial & boundary conditions are converted into non-dimensional form. Exact analytical solutions are obtained for dimensionless fractional governing equations which consist of momentum and energy equations by using Laplace transform method. Special cases are investigated of the obtained solutions and it is noticed that some well-known results are achieved published in literature from these special cases. At the end, for graphical illustration the influences of different physical parameters like radiation, Prandtl, fractional parameter, Grashof numbers and Magneto hydro dynamic are checked graphically.

5.
Sci Rep ; 12(1): 22371, 2022 Dec 26.
Article in English | MEDLINE | ID: mdl-36572708

ABSTRACT

In this research article the heat transfer of generalized second grade fluid is investigated with heat generation. The fluid flow is analyzed under the effects of Magneto hydrodynamics over an infinite vertical flat plate. The Newtonian heating phenomenon has been adopted at the boundary. For this purpose the problem is divided into two compartments i.e. momentum equation and energy equations. Some specific dimensionless parameters are defined to convert the model equations into dimensionless system of equations. The solutions for dimensionless energy and momentum equations are obtained by using the Laplace transform technique. From obtained results by neglecting magneto hydrodynamic effects and heat source some special case are achieved which are already published in literature. The case for which the fractional parameter approaches to the classical order is also discussed and it has been observed that it is convergent. Finally, the influences of different physical parameters are sketched graphically. It has been observed that for increasing values of Prandtl number the velocity and temperature decreases, for increasing values of Grashof number the velocity of the fluid increases. Also it has been investigated that for increasing values of fractional parameter the velocity and temperature of the fluid increases.

6.
Sci Rep ; 12(1): 19591, 2022 Nov 15.
Article in English | MEDLINE | ID: mdl-36379966

ABSTRACT

In this paper, we have been study a hybrid nanofluid over an exponentially oscillating vertical flat plate. Therefore the fractional derivatives definition of Caputo-Fabrizio approach is applied to transform the classical model for this hybrid nanofluid to fractional model. Together with an oscillating boundary motion, therefore the heat transfer is cause as a result of the buoyancy force produce due temperature differences between the plate and the fluid. The dimensionless classical model is generalized by transforming it to the time fractional model using Caputo-Fabrizio time fractional derivative. Exact analytical solutions are obtained by using Laplace transform method to the set of dimensionless fractional governing equations, containing the momentum and energy equations subjected to the boundary and initial conditions. Numerical computations and graphical illustrations are used to checked the results of the Caputo-Fabrizio time-fractional parameter, the second-grade parameter, the magnetic parameter and the Grashof numbers on the velocity field. An assessment for time spin-off is shown graphically of integer order versus fractional-order for these non-Newtonian hybrid nanofluid through Mathcad software. The fluid velocity increases for increasing the value of the fractional parameter, second-grade parameter and Grashof number. Also for increasing the values of the MHD parameter the fluid velocity decreases.

7.
Microsc Res Tech ; 85(7): 2514-2525, 2022 Jul.
Article in English | MEDLINE | ID: mdl-35388567

ABSTRACT

The participation of numerous physicochemical and biological functions maintains the evolution and expansion of the remarkable nature. Due to its vast applicability in several engineering disciplines, naturally occurring bio-mineralization or microbially induced calcium carbonate (MICP) precipitation is attracting more interest. Cave bacteria contribute to the precipitation of calcium carbonate (CaCO3 ). In the present study, soil sediments were collected from Kashmir cave, KPK, Pakistan, and plated on B4 specific nutrients limited medium for bacterial isolation and the viable bacterial count was calculated. Three bacterial strains named GSN-11, TFSN-14, and TFSN-15 were capable of precipitating CaCO3 . These bacterial isolates were identified through 16S rRNA gene sequencing and strain GSN-11 was identified as Bacillus toyonensis, TFSN-14 as Paracoccus limosus and TFSN-15 as Brevundimonas diminuta. Enhanced CaCO3 precipitation potential of these bacteria strains was observed at 25°C and pH 5. The precipitated CaCO3 was confirmed by scanning electron microscopy, X-ray powder diffraction, and Fourier transform infra-red spectroscopy. The findings showed that the precipitates were dominated by calcite, aragonite, and nanosize vaterite. Current research suggests that precipitation of CaCO3 by proteolytic cave bacteria is widespread in Kashmir cave and these bacterial communities can actively contribute to the formation of CaCO3 by enhancing the pH of the microenvironment. RESEARCH HIGHLIGHTS: Kashmir cave inhabit potentially active bacteria in terms of biogeochemical processes. Cave bacteria significantly precipitated CaCO3 . Calcite, aragonite, and nanosize vaterite were dominant in precipitates.


Subject(s)
Bacteria , Calcium Carbonate , Bacteria/genetics , Calcium Carbonate/chemistry , Chemical Precipitation , Pakistan , RNA, Ribosomal, 16S/genetics
8.
J Healthc Eng ; 2021: 9954089, 2021.
Article in English | MEDLINE | ID: mdl-34336174

ABSTRACT

Biosensor is a means to transmit some physical phenomena, like body temperature, pulse, respiratory rate, electroencephalogram (EEG), electrocardiogram (ECG), and blood pressure. Such transmission is performed via Wireless Medical Sensor Network (WMSN) while diagnosing patients remotely through Internet-of-Medical-Things (IoMT). The sensitive data transmitted through WMSN from IoMT over an insecure channel is vulnerable to several threats and needs proper attention to be secured from adversaries. In contrast to addressing the security of all associated entities involving patient monitoring in the healthcare system or ensuring the integrity, authorization, and nonrepudiation of information over the communication line, no one can guarantee its security without a robust authentication protocol. Therefore, we have proposed a lightweight and robust authentication scheme for the network-enabled healthcare devices (IoMT) that mitigate all the identified weaknesses posed in the recent literature. The proposed protocol's security has been analyzed formally using BAN logic and ProVerif2.02 and informally using pragmatic illustration. Simultaneously, at the end of the paper, the performance analysis result shows a delicate balance of security with performance that is often missing in the current protocols.


Subject(s)
Computer Security , Internet of Things , Computer Communication Networks , Confidentiality , Delivery of Health Care , Humans
9.
Sci Rep ; 11(1): 4265, 2021 Feb 19.
Article in English | MEDLINE | ID: mdl-33608600

ABSTRACT

The present research article is directed to study the heat and mass transference analysis of an incompressible Newtonian viscous fluid. The unsteady MHD natural convection flow over an infinite vertical plate with time dependent arbitrary shear stresses has been investigated. In heat and mass transfer analysis the chemical molecular diffusivity effects have been studied. Moreover, the infinite vertical plate is subjected to the phenomenon of exponential heating. For this study, we formulated the problem into three governing equations along with their corresponding initial and boundary conditions. The Laplace transform method has been used to gain the exact analytical solutions to the problem. Special cases of the obtained solutions are investigated. It is noticed that some well-known results from the published literature are achieved from these special cases. Finally, different physical parameters' responses are investigated graphically through Mathcad software.

10.
Environ Sci Pollut Res Int ; 28(8): 10234-10247, 2021 Feb.
Article in English | MEDLINE | ID: mdl-33170468

ABSTRACT

The high-risk organic pollutants produced by industries are of growing concern. The highly porous coal-based activated carbon (AC) having a specific surface area of 3452.8 m2/g is used for the adsorption of azo dye from synthetic solution. The sorbent is characterized through BET, SEM, TEM, XRD, FT-IR, TGA, and zeta potential. The sorbent exhibits - 18.7 mV surface charge, which is high enough for making suspension. The maximum dye uptake of 333 mg/g is observed in sorbent under acidic medium. The thermodynamics parameters like ∆G, ∆H, and ΔS were found to be - 12.40 kJ mol-1, 39.66 kJ mol-1, and 174.55 J mol-1 K-1 at 293 K, respectively, revealing that the adsorption mechanism is spontaneous, endothermic, and feasible. The experimental data follows the Langmuir and D-R models. The adsorption follows pseudo 2nd-order kinetics. DFT investigation shows that the dye sorption onto AC in configuration No. 4 (CFG-4) is more effective, as this configuration has high ∆H (enthalpy change) and adsorption energy (Eads). This is confirmed by Mullikan atomic charge transfer phenomenon.


Subject(s)
Charcoal , Water Pollutants, Chemical , Adsorption , Azo Compounds , Coal , Hydrogen-Ion Concentration , Kinetics , Spectroscopy, Fourier Transform Infrared , Thermodynamics , Water Pollutants, Chemical/analysis
11.
J Proteome Res ; 19(8): 3201-3210, 2020 08 07.
Article in English | MEDLINE | ID: mdl-32551656

ABSTRACT

The thermal stability of purified acid phosphatase from the germinating seedlings of Coronopus didymus (Jangli halon) was investigated by studying the impact of various thermodynamic parameters [t1/2, Ed, ΔH° (enthalpy change), ΔG° (free energy change), and ΔS° (entropy change)] of heat treatment in the temperature range of 55-75 °C. The thermal denaturation of acid phosphatase, assessed by loss in activity, was evidently followed by first-order kinetics, which varies with time and yield during the process of denaturation. The half-life of the enzyme was 693 min at 55 °C. The Ed (activation energy of denaturation) was calculated by the Arrhenius plot (30 kcal mol-1), and the Z-value was 17.3 °C. The various thermodynamic parameters studied were as follows: ΔH°, the change in enthalpy of inactivation, was 121.93 kJ mol-1 at 55 °C; ΔG°, the change in free energy of inactivation, was 110.65 kJ mol-1 at 55 °C; and ΔS°, the change in entropy of inactivation, was 34.39 J mol-1 k-1 at 55 °C. This suggests that acid phosphatase activity is thermostable to long heat treatment up to 60 °C.


Subject(s)
Acid Phosphatase , Brassicaceae/enzymology , Plant Proteins , Seedlings , Enzyme Stability , Hydrogen-Ion Concentration , Kinetics , Seedlings/enzymology , Thermodynamics
12.
J Mol Model ; 25(7): 189, 2019 Jun 14.
Article in English | MEDLINE | ID: mdl-31197487

ABSTRACT

Quantum chemical computations were applied to investigate the characteristics of open-shell hydrogen-bonding interactions in the complexes of carbamic acid (NH2COOH, CA) with HO2, HOS and HSO radicals. All the resulting complexes were studied using the MP2, B3PW91 and B3LYP computational levels and 6311++G** basis set. Geometry optimizations show that the O-H⋯O contact is stronger than N-H⋯O and S-H⋯O. The interaction energies revealed that all the radicals form stronger hydrogen bonded complexes at site-1, as confirmed by electron-density (ρ) and corresponding Laplacian (∇2ρ) values obtained by atoms in molecule (AIM) analysis. Non-covalent interaction and reduced density gradient analysis support the AIM results. Natural bond orbital analysis was employed to obtain the stabilization energies (E(2)) due to charge delocalization between the interacting units. Energy decomposition analysis suggests that, for the title complexes, the exchange energy makes a larger contribution to the total interaction energy compared to other energy terms. Graphical abstract Open-shell H-bondinginteraction between carbamic acid (NH2COOH) and HO2, HOS or HSOradicals.

13.
J Coll Physicians Surg Pak ; 26(11): 920-923, 2016 Nov.
Article in English | MEDLINE | ID: mdl-27981929

ABSTRACT

To conduct the bibliometric analysis of the Journal of the College of Physicians and Surgeons Pakistan (JCPSP) from 2012 to 2014. The prime objectives of this report were to determine the number and percentage of articles by year, authorship pattern, gender and geographical affiliation, ranking by subject and citation analysis. A data collection instrument was developed as bibliometric form. The data was analysed using the Microsoft Excel spread sheet. Editorials and letters to editors were excluded. There were 1106 total research documents, including 721 original articles and 385 case reports. A rapid increase in number of articles per year was noticed, more original papers than case reports. Majority of the authors were male. The contribution of Balochistan and Khyber Pakhtunkhwa was less than the other provinces. JCPSP was the most cited document in the reference list of the research documents. The scholars of Khyber Pakhtunkhwa and Balochistan and female researchers should give more attention in writing quality articles eligible for consideration at this Journal. It is also suggested that writers should be compelled to address such fields of medical sciences as neurology, nephrology, anatomy and pharmacology, while writing original articles and case reports.


Subject(s)
Bibliometrics , Biomedical Research , Periodicals as Topic , Publishing/statistics & numerical data , Humans , Pakistan
SELECTION OF CITATIONS
SEARCH DETAIL
...