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Protecting the confidentiality of medical images during storage and transmission is vital in modern healthcare systems. This paper presents an innovative and efficient encryption algorithm tailored for both grayscale and color medical images. The proposed method combines the Modified Improved Logistic Exponential (MILE) chaotic map with a multi-level Fibonacci Q-matrix to enhance security, randomness, and resilience. By overcoming the limitations of conventional one-dimensional chaotic systems, the MILE map significantly improves the unpredictability of the permutation and diffusion processes. The encryption procedure begins with extracting key-dependent parameters from the input image, which are then used to generate chaotic sequences for pixel permutation and XOR-based diffusion. Additionally, image blocks undergo multi-level Q-matrix transformations to bolster further the scheme’s resistance to statistical analysis, noise disruption, and differential attacks. Extensive experiments were conducted using standard evaluation metrics such as information entropy, correlation coefficients, NPCR, UACI, PSNR, and key sensitivity. The proposed scheme achieved strong performance, with an NPCR of 99.63%, a UACI of 33.47%, and entropy values nearing the ideal 7.999, indicating excellent randomness. Moreover, the algorithm is computationally efficient, requiring just 0.42 s to encrypt a 256 × 256 image, making it highly suitable for real-time and telemedicine applications. Overall, the proposed approach ensures robust protection for sensitive medical data and surpasses several existing image encryption techniques in performance.

This study focuses on natural convection within a square porous cavity that is partially heated/(cooled) along its left and bottom/(right and top) walls, filled with a nanofluid and subjected to an external horizontal magnetic field. All walls are assumed to be impermeable. The Buongiorno mathematical model has been employed to take into consideration Brownian and thermophoretic diffusion effect, in order to show the spatial distribution of the local nanoparticle concentration. Using the finite volume method and the SIMPLE algorithm, the governing equations have been discretized. The results are depicted in terms of streamlines, isotherms, and iso-concentration contours, as well as through the evaluation of the average Nusselt number for different values of Darcy number, Da , Hartmann number, Ha , Rayleigh number, R T , thermophoresis number N t , Brownian number N b and Buoyancy ratio N r . The Lewis and Prandtl numbers are assumed to remain constant, with Le =25 and Pr =7, and the porosity of the cavity is assumed to be 0.8 (a porosity of 0.8 corresponds to a moderately dense porous medium, typical of materials such as metal foams, fibrous layers, or certain granular media). All of these variables were discovered to have significant influences on the strength of nanofluid flows, as well as the flow structure and the rate of heat transfer.

This paper is dedicated to deal with thermosolutal natural convection within an enclosure submitted to destabilizing heat and mass fluxes and confining an electrically conducting binary mixture. The cavity is bathed in an external magnetic field and Soret and Dufour effects are considered. An approximate analytical solution is derived, valid in the limit of a shallow enclosure and confirmed numerically by using a finite difference method. The results show the existence of six regions in plane describing different flow behaviours. The critical Hartman number and critical inclination of magnetic field, which lead to the suppression of convective flows are calculated analytically vs. the control parameters. The obtained results illustrate a significant impact of the combined effects of the inclined magnetic field (via its intensity and inclination) and the Soret and Dufour parameters on different thresholds of convection and the resulting heat and mass transfer. Moreover, the increase in the inclination of the magnetic field in the range has a stabilizing/(destabilizing) effect with respect to stationary and sub-critical convections, regardless of the Hartmann number.

The facial expression recognition is an ocular task that can be performed without human discomfort, is really a speedily growing on the computer research field. There are many applications and programs uses facial expression to evaluate human character, judgment, feelings, and viewpoint. The process of recognizing facial expression is a hard task due to the several circumstances such as facial occlusions, face shape, illumination, face colors, and etc. This paper present a PCA methodology to distinguish expressions of faces under different circumstances and identifying it. Relies on Eigen faces technique using standard Data base images. So as to overcome the problem of difficulty to computers to identify the features and expressions of persons.

Hand gesture recognition is an important aspect of the computing models, which makes the communication more natural and effectively. In this paper we propose a methodology of recognizing Hand gesture (zero to five) by using principal component analysis method. Based on Euclidian distance and Mahalanobis distance to find the near neighbour in PCA algorithm, and compare between them from zero to five. In order to make computers capable of understanding the human hand gestures and controlling the various applications that can be used for security purpose.

AbstractThis paper presents a detailed study on the effect of the strain reducing layer (SRL) made with InGaAsSb on the photoluminescence (PL) of type I InAs/GaAs quantum dots (QDs). For the InGaAsSb SRL, measurement results have shown that the emission wavelength reaches 1.4 µm for the ground state (GS) and 1.33 µm for the first excited state (ES) at room temperature (RT). Besides, the investigation of the temperature-dependent PL shows the strong effect of SRL in reducing the barrier potential at the interface between the capping layer and QDs, and increasing the carrier injection efficiency inside the QDs, at low temperature, leading to an enhancement of the luminescence of this sample. Furthermore, the increase of excitation density from 40 to 200 W/cm2 for all temperature between 10 and 220 K reveals that incorporating InGaAsSb SRL in InAs/GaAs QDs is of great importance on the understanding of some devices operating at room temperature or higher.Graphical AbstractEvolution of the integrated PL intensity of the GS and ES transitions vs. excitation density of InGaAsSb quantum dots for different temperatures.

Allylic oxygenated derivatives of himachalenes are highly valued molecules due to their potential applications in perfumery, cosmetics, and pharmaceuticals. Previous attempts at catalyzed allylic oxidation of himachalenes led to the formation of a very stable η3-allyl palladium complex, preventing any further reaction development. Herein, we present the first successful palladium-catalyzed synthesis of a novel allylic acetoxylated derivative of himachalenes. This reaction was achieved by incorporating an aromatic ring into the substrate structure. The resulting intermediate complex was isolated and characterized using nuclear magnetic resonance spectroscopy and X-ray crystallography. Density functional theory (DFT) calculations were performed to compare the reactivity of the newly synthesized complex with previously reported ones. The theoretical results confirm that the introduction of an aromatic ring enhances the reactivity of the η³-allyl palladium complex, thereby facilitating the desired transformation.

Purpose Primary immunodeficiencies (PIDs) are a large group of diseases characterized by susceptibility to not only recurrent infections but also autoimmune diseases and malignancies. The aim of this study was to describe and analyze the distribution, clinical features and eventual outcome of PID among Tunisian patients. Methods We reviewed the record of 710 patients diagnosed with Primary Immunodeficiency Diseases (PIDs) from the registry of the Tunisian Referral Centre for PIDs over a 25-year period. Results The male-to-female ratio was 1.4. The median age at the onset of symptoms was 6 months and at the time of diagnosis 2 years. The estimated prevalence was 4.3 per 100,000 populations. The consanguinity rate was found in 58.2 % of families. According to the International Union of Immunological Societies classification, spectrums of PIDs were as follows: combined T-cell and B-cell immunodeficiency disorders account for the most common category (28.6 %), followed by congenital defects of phagocyte (25.4 %), other well-defined immunodeficiency syndromes (22.7 %), predominant antibody deficiency diseases (17.7 %), diseases of immune dysregulation (4.8 %), defect of innate immunity (0.4 %) and complement deficiencies (0.4 %). Recurrent infections, particularly lower airway infections (62.3 %), presented the most common manifestation of PID patients. The overall mortality rate was 34.5 %, mainly observed with combined immunodeficiencies. Conclusion The distribution of PIDs was different from that reported in Western countries, with a particularly high proportion of Combined Immunodeficiencies and phagocyte defects in number and/or function. More is needed to improve PID diagnosis and treatment in our country.

Objective Abdominal tuberculosis is one of the most frequent extra-pulmonary localizations. Its diagnosis is difficult and may lead to a delayed prescription of specific treatment. This study is aimed at stressing the role of laparoscopy associated with a biopsy in the diagnostic confirmation of abdominal tuberculosis particularly in doubtful cases. Methods The diagnostic features of 11 cases hospitalized for abdominal tuberculosis in the Paediatric Surgery Department of Fattouma Bourguiba Hospital in Monastir for a 6-year period (2001–2006), were evaluated retrospectively. The diagnosis of abdominal tuberculosis was substantiated histopathologically by laparoscopy in all cases. The epidemiological and clinical characteristics along with the laboratory, radiological and histological data were studied. Results Eleven cases of abdominal tuberculosis with a mean age of 5.6 years were diagnosed. It was peritoneal tuberculosis in all cases and associated with intestinal localization in one case. A conversion to laparotomy was practiced in three patients: appendicular plastron in one case, pseudo-tumor aspect of an intestinal loop in another case and because of their pathological aspect appendicectomy and caecum biopsy in the third. The diagnosis was confirmed histologically by biopsies in nine cases and on excision pieces in the other two cases. All patients had an uneventful course with an antituberculosis treatment. Conclusion Abdominal tuberculosis is still frequent in Tunisia. Because of its non-specific clinical presentation and the limited means of investigation, a laparoscopy with biopsy should be practiced as first line diagnostic tool in case of doubtful abdominal tuberculosis. The earlier the diagnosis is established and an adapted antituberculosis treatment is started, the better the prognosis is.