Motion of Bishop Frenet Offsets of Ruled Surfaces in E

The main goal of this paper is to study the motion of two associated ruled surfaces in Euclidean 3-space E3. In particular, the motion of Bishop Frenet offsets of ruled surfaces is investigated. Additionally, the characteristic properties for such ruled surfaces are given. Finally, an application is presented and plotted using computer aided geometric design

دراسات على تكوين وتركيب بعض مشتقات ثنائي الفوسفازانات الحلقية مع اليوريا والثيويوريا

The methods of preparation and possible reaction mechanisms for the formation of some geminal and nongeminal aminocyclodiphosph (v) azanes of the type (II - V) are discussed. These cyclodiphosphazanes obtained from the interaction of chlorocyclodiphosphazanes (I) with some bifunctional reagents (such as phenylurea, diphenylurea, thiourea and its phenyl derivatives) in acetonitrile, have been investigated using infrared, ultraviolet, H n.m.r. and mass spectrometric data.إشتملت هذه الدراسة على تحضير بعض مشتقات ثنائي الفوسفازانات الحلقية مع اليوريا والثيويوريا حيثا تم فصل بعض أمينو ثنائي الفوسفازانات الحلقية الجيمينيلية وغير الجيمينيلية ذاتا النشاط البيولوجي كمضادات للخلايا السرطانية ، كما تمت دراسة التراكيب الجزيئية لذه المشتقات بدراسة أطياف الأشعة فوق البنفسجية والأشعة تحت الحمراء وطيف الرنين النووي المغناطسي وأطياف الكتلة لهذه المركبات ، وقد أمكن التحقق من التراكيب الجزيئية لبعض هذه المشتقات باستخدام طريقة الإرتباط المجالي في طيف الكتلة حيث أمكن التأكد من وجود الأيونات غير الثابتة

Evolution of Translation Surfaces in Euclidean 3-Space E3

Geometry and kinematics have been intimately connected in their historical evolution and, although it is currently less fashionable, the further development of such connections is crucial to many computer-aided design and manufacturing. In this paper, the evolution of the translation surfaces and their generating curves in E3 are investigated. Integrability conditions of the Gauss-Weingarten equations are obtained. Kinematics of moving frame fields associated to these surfaces are described. The evolution equations of the Christoffel symbols, the second fundamental quantities and Gauss-Codazzi equations for the motion are established. Thus, the evolution equations of the curvatures in terms of their intrinsic geometric formulas are derived. Two examples of translation surfaces and their motions are considered and plotted

Stability of deformed osculating hyperruled surfaces

The mean curvature vector plays an important role in the investigation of crystallographie point of view of the minimal surfaces

Ruled W-surfaces in Minkowski 3-space ℜ13\Re _{1}^{3}

summary:In this paper, we study a spacelike (timelike) ruled W-surface in Minkowski 3-space which satisfies nontrivial relation between elements of the set $\lbrace K,\ K_{II},\ H,\ H_{II}\rbrace$, where $(K, H)$ and $(K_{II}, H_{II})$ are the Gaussian and mean curvatures of the first and second fundamental forms, respectively. Finally, some examples are constructed and plotted

Use of cerebrospinal fluid flow rates measured by phase-contrast MR to differentiate normal pressure hydrocephalus from involutional brain changes

Aim: The aim of our study was to assess the value of cerebrospinal fluid flow rates measured by phase-contrast MR in cases of normal pressure hydrocephalus (NPH) and to differentiate it from brain atrophy. Material and methods: A total of 26 participants were enrolled into this study, consisting of 15 patients considered to have NPH, 6 patients with atrophic dilatation of the ventricular system not proportional with cerebral sulci, and 5 control cases. All cases were studied using 1.5 T MRI scanner between January 2012 and June 2014. Results: In NPH patients with high stroke volume, we reported marked elevation of the systolic peak and mean velocity as well as stroke volume in comparison with healthy volunteers, indicating a hyperdynamic CSF circulation. On the other hand we studied six patients with involutional brain changes who were found to have non-statically significant lower systolic peak velocity, systolic mean velocity and stroke volume values in comparison with healthy volunteers indicating a hypodynamic CSF circulation and a diagnosis of atrophy. Conclusion: The mean CSF flow rate may be useful in the diagnosis and differential diagnosis, and the prediction of the potential benefits of surgical intervention for patients considered to have NPH

Nanotechnology as a Promising Approach to Combat Multidrug Resistant Bacteria: A Comprehensive Review and Future Perspectives

The wide spread of antibiotic resistance has been alarming in recent years and poses a serious global hazard to public health as it leads to millions of deaths all over the world. The wide spread of resistance and sharing resistance genes between different types of bacteria led to emergence of multidrug resistant (MDR) microorganisms. This problem is exacerbated when microorganisms create biofilms, which can boost bacterial resistance by up to 1000-fold and increase the emergence of MDR infections. The absence of novel and potent antimicrobial compounds is linked to the rise of multidrug resistance. This has sparked international efforts to develop new and improved antimicrobial agents as well as innovative and efficient techniques for antibiotic administration and targeting. There is an evolution in nanotechnology in recent years in treatment and prevention of the biofilm formation and MDR infection. The development of nanomaterial-based therapeutics, which could overcome current pathways linked to acquired drug resistance, is a hopeful strategy for treating difficult-to-treat bacterial infections. Additionally, nanoparticles’ distinct size and physical characteristics enable them to target biofilms and treat resistant pathogens. This review highlights the current advances in nanotechnology to combat MDR and biofilm infection. In addition, it provides insight on development and mechanisms of antibiotic resistance, spread of MDR and XDR infection, and development of nanoparticles and mechanisms of their antibacterial activity. Moreover, this review considers the difference between free antibiotics and nanoantibiotics, and the synergistic effect of nanoantibiotics to combat planktonic bacteria, intracellular bacteria and biofilm. Finally, we will discuss the strength and limitations of the application of nanotechnology against bacterial infection and future perspectives