Kardar-Parisi-Zhang growth on one-dimensional decreasing substrates

Recent experimental works on one-dimensional (1D) circular Kardar-Parisi-Zhang (KPZ) systems whose radii decrease in time have reported controversial conclusions about the statistics of their interfaces. Motivated by this, we investigate here several 1D KPZ models on substrates whose size changes in time as $L(t)=L_0 + \omega t$, focusing on the case $\omega<0$. From extensive numerical simulations, we show that for $L_0 \gg 1$ there exists a transient regime in which the statistics is consistent with that of flat KPZ systems (the $\omega=0$ case), for both $\omega0$. Actually, for a given model, $L_0$ and $|\omega|$, we observe that a difference between ingrowing ($\omega0$) systems arises only at long times ($t \gtrsim t_c=L_0/|\omega|$), when the expanding surfaces cross over to the statistics of curved KPZ systems, whereas the shrinking ones become completely correlated. A generalization of the Family-Vicsek scaling for the roughness of ingrowing interfaces is presented. Our results demonstrate that a transient flat statistics is a general feature of systems starting with large initial sizes, regardless their curvature. This is consistent with their recent observation in ingrowing turbulent liquid crystal interfaces, but it is in contrast with the apparent observation of curved statistics in colloidal deposition at the edge of evaporating drops. A possible explanation for this last result, as a consequence of the very small number of monolayers analyzed in this experiment, is given. This is illustrated in a competitive growth model presenting a few-monolayer transient and an asymptotic behavior consistent, respectively, with the curved and flat statistics.Comment: 5 pages, 3 figure

Wandering Spleen with Splenic Vein Thrombosis: A Case Report

A wandering spleen is a rare clinical occurrence with fewer than 500 cases reported and an incidence of less than 0.2%1, 2. The spleen is an important component of the reticuloendothelial system, which is involved in immunological defence and can serve as a storage site for red blood cells3. The spleen is normally supported by the gastrosplenic, splenorenal and splenocolic ligaments, whereby failure of attachment of these ligaments to the spleen’s overlying peritoneum results in a hypermobile spleen3, 4. All cases of a wandering spleen have been found associated with a long splenic pedicle which consists of the splenic vessels and the tail of the pancreas2-4. A wandering spleen can be either congenital or acquired. In the congenital condition the ligaments fail to develop properly, whereas in the acquired form the hormonal effects of pregnancy and abdominal wall laxity are proposed as determining factors 5-7. In addition, failure of fusion of the dorsal mesogastrium during foetal development resulting in the characteristic long vascular pedicle has been attributed8. However, the precise aetiology of the wandering spleen is not known 2. Key words: Spleen, wandering, splenic, vein, thrombosi

One-point height fluctuations and two-point correlators of (2+1)(2+1) cylindrical KPZ systems

While the 1-point height distributions (HDs) and 2-point covariances of $(2+1)$ KPZ systems have been investigated in several recent works for flat and spherical geometries, for the cylindrical one the HD was analyzed for few models and nothing is known about the spatial and temporal covariances. Here, we report results for these quantities, obtained from extensive numerical simulations of discrete KPZ models, for three different setups yielding cylindrical growth. Beyond demonstrating the universality of the HD and covariances, our results reveal other interesting features of this geometry. For example, the spatial covariances measured along the longitudinal and azimuthal directions are different, with the former being quite similar to the curve for flat $(2+1)$ KPZ systems, while the latter resembles the Airy$_2$ covariance of circular $(1+1)$ KPZ interfaces. We also argue (and present numerical evidence) that, in general, the rescaled temporal covariance $\mathcal{A}(t/t_0)$ decays asymptotically as $\mathcal{A}(x) \sim x^{-\bar{\lambda}}$ with an exponent $\bar{\lambda} = \beta + d^*/z$, where $d^*$ is the number of interface sides kept fixed during the growth (being $d^* = 1$ for the systems analyzed here). Overall, these results complete the picture of the main statistics for the $(2+1)$ KPZ class.Comment: 10 pages, 8 figures, 2 table

A Computational Model for Temperature Monitoring During Human Liver Treatment by Nd:YaG Laser Interstitial Thermal Therapy (LITT)

Describing heat transfer in biological organs is absolutely challenging because it is involved with many complex phenomena. Therefore, understanding the optical and thermal properties of living system during external irradiation sources such as laser interstitial thermal therapy (LITT) are too important for therapeutic purposes, especially for hyperthermia treatments. The purpose of this study was to determine a proper laser power and irradiation time for LITT applicator to irradiate liver tissue during hyperthermia treatment. For this aim, bioheat equation in one-dimensional spherical coordinate is solved by Green function method to simulate temperature distribution and rate of damage around irradiated target and how thermal and optical properties such as laser power, laser exposure time, and blood perfusion rate affect the rate of temperature distribution. Guiding equations according to the suggested boundary conditions are written and solved by MATLAB software. The outcomes show that increasing laser exposure time and power increase the temperature, especially at the nearest distance from the center of diffusion. Accordingly, a decrease in blood perfusion rate leads to decrease temperature distribution. The findings show that the model is useful to help the physicians to monitor the amount of heat diffusion by laser power during the treatment to protect healthy cells

Physical Properties of (Basalt-Ni) System by Thermal Spray Flame Technique

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; تعاني العديد من السطوح تشققات وتأكل خارجي مثل الريش التوربينية وانابيب النفط ولأجل حل تلك المشاكل يتم استخدام طلاءات ذات متانة عالية وكلفة واطئة. ففي البحث الحالي تم استخدام مسحوق صخور البازلت((Basalt ذات الاكاسيد المتعددة مدعمة بمادة معدنية (Ni)50% تم رش النماذج المجهزة بتقنية الرش الحراري بواسطة اللهب وعند مسافات رش متعددة هيcm &nbsp;(10,12,14,16,18,20) وبعد اكمال تحضير النماذج المطلية على قاعدة من الفولاذ السبائكي تم اجراء عملية التلبيد للعينات وعند معاملة ((700℃, 900℃,1100℃ وبزمن ساعتين. اما الفحوص الميكانيكية تمثلت ب( قوة التلاصق, المسامية, الصلادة, البلى) وكما تم اجراء فحص بالمجهر الالكتروني الماسح(SEM) للعينات المحضرة قبل وبعد عملية التلبيد. اظهرت نتائج الفحص ان احسن مسافة رش كانت cm 16 وافضل معاملة حرارية هي ( (1100℃ وذلك بالاعتماد على كل من نتائج فحوص قوة التلاصق التي بلغتMPa(24.43) و المسامية التي بلغت %((8.653 وصلادة فيكرز هي (HV 1140) وكما ووجد عند سرعة انزلاقية ثابتة هي (cm/min.12000) وعند زمن خمسة دقائق وحمل ( (20Nالحصول على اوطئ معدل بلى(wear)هو (0.397), اما نتائج فحص المجهر الالكتروني الماسح اوضحت تناسق سطحي واضح بعد اجراء المعاملات الحرارية مع وجود قليل للمسامات وعند افضل معاملة حرارية هي ( (1100℃.Many surfaces suffer cracks and external corrosion such as turbo blades and oil pipes. In order to solve these problems are used coatings of high durability and low cost. In the current research, the power of the basalt with multiple oxides supported by metal (Ni) 50% was sprayed models with thermal spraying by flame and at multiple spraying distances of (10,12,14,16,18,20) cm after the preparation of the models coated on a base of alloy steel, the process of sintering of the samples at (700, 900, 1100) ℃ and within two hours have been done. The mechanical tests were (strength adhesion, porosity, hardness, wear, and tear) (SEM) for prepared samples before and after sintering. The results showed that the best spraying distance was 16 cm and the best heat treatment is ( (1100 ℃), depending on the results of the adhesion strength tests at (24.43 MPa) and (8.653%) porosity, (1140 Hv) and the hardness of the Vickers and at a constant sliding speed (12000 cm/min). The results of the scanning electron microscopy showed clear surface consistency after thermal conductivity with a few pores and treatments the best (1100.)

Алгоритм определения оптимального числа волокон используемых при внутритканевой фотодинамической терапии рака молочной железы на основании диффузионного уравнения

It is essential in interstitial Photodynamic therapy (iPDT) treatment planning to ensure a homogeneous distribution within a tumor volume using cylindrical diffusing fibers while keeping the surrounding tissue intact. Light distribution is simulated through two algorithms based on the diffusion equation assuming diffusers as light sources. The first algorithm analyzes the diffusion equation and studies the effects of different variables (optical properties, delivered power, diffuser length, and position). Next, optical properties of breast were applied to estimate the volume that receives accepted light dose from one diffuser. In the second algorithm, multiple diffusers were simulated in order to find the relation between the volume and the number of required diffusers which are needed to cover cubical or cylindrical volume with sufficient light dose. Throughout this study, real values of optical properties, clinical laser power, and treatment time were considered to evaluate sufficient light doses. This study is in agreement with previous works in that optical properties are the major factors influencing light distribution in iPDT. It is shown that for a homogeneous phantom mimicking breast cancer and cubical or cylindrical shape, the number of required fibers N equal W×L or D2 respectively.При планировании внутритканевой фотодинамической терапии (iPDT ) с использованием цилиндрических диффузных волокон важно обеспечить однородное распределение света по всему объему опухоли, сохранив при этом целостность окружающей ткани. Авторы данной статьи смоделировали распределение света с помощью двух алгоритмов, основанных на уравнении диффузии, в которых в качестве источников света используются цилиндрические диффузоры. Первый алгоритм анализирует уравнение диффузии и изучает влияние различных переменных (оптических свойств источника, применяемой мощности, длины диффузора и его положения). Затем были использованы параметры оптических свойств молочной железы для оценки объема, который рассчитывает световую дозу от одного диффузора. Во втором алгоритме было смоделировано несколько рассеивателей для нахожде ния соотношения между объемом и количеством рассеивателей, необходимых для покрытия кубического или цилиндрического объема достаточной световой дозой. На протяжении всего этого исследования рассматривались реальные значения оптических свойств, клинической мощности лазера и времени лечения для оценки достаточных световых доз. Это исследование согласуется с предыдущими работами в том, что оптические свойства являются основными факторами, влияющими на распределение света при iPDT. Показано, что, для однородного фантома, имитирующего рак молочной железы, кубической или цилиндрической формы, количество требуемых волокон N равно W×L или D2 , соответственно

Juxtocellar Structures in Euglossine Bees: A New Character for Corbiculate Studies (Hymenoptera: Apidae).

Es wird eine neuartige morphologische Struktur bei Prachtbienen (Apinae: Euglossini) dargestellt. Diese findet sich posterolateral der Ocelli und wird als “Juxtocellarstruktur” bezeichnet. Sie wird in ihrer Ausprägung bei den Euglossinen beschrieben. Homologe Strukturen wurden bei verschiedenen verwandten Gruppen von Apidae gefunden, z. B. bei Anthophorini, Centridini und Eucerini, während sie bei anderen fehlen, z. B. bei Xylocopinae und Nomadinae. Bemerkenswerterweise sind Juxtocellarstrukturen verlorengegangen als Apomorphie bei allen anderen korbikulaten Triben der Apidae (darunter die Bombini, Meliponini, Apini, Electrobombini, Electrapini und Melikertini), ein Merkmalsmuster, das mit den aktuellen phylogenetischen Hypothesen dieser Gruppe übereinstimmt.ResumenSe describe e ilustra una estructura morfológica nueva para abejas de las orquídeas (Apidae: Euglossini). Estas diminutas estructuras, aquí nombradas “estructuras yuxtaocelares”, se ubican posterolateralmente a los ocelos. Se describe la diversidad de su forma dentro de Euglossini. Estructuras homólogas fueron encontradas en algunos linajes relacionados de abejas de la familia Apidae (Anthophorini, Centridini, Eucerini), mientras que en otros las estructuras estuvieron ausentes (Xylocopinae, Nomadinae). De manera relevante las estucturas yuxtaocelares se hallan apomórficamente ausentes en todas las otras tribus de abejas con corbícula (Bombini, Meliponini, Apini, Electrobombini, Electrapini y Melikertini), lo cual concuerda con hipótesis filogenéticas actuales para este grupo.StichwörterApoidea, Anthophila, comparative morphology, Euceriti, Apiti, phylogeny.A new morphological structure is described and figured for orchid bees (Apinae: Euglossini). These minute features are located posterolateral to the ocelli and are termed “juxtocellar structures”. The diversity of their form across Euglossini is described. Homologous structures were found in some related lineages of apid bees (e.g., Anthophorini, Centridini, Eucerini) while in others the structures were absent (e.g., Xylocopinae, Nomadinae). Most notably juxtocellar structures are apomorphically lost in all other corbiculate apine tribes (i.e., Bombini, Meliponini, Apini, Electrobombini, Electrapini, and Melikertini), a pattern which is in accordance with current phylogenetic hypotheses for the clade.ResumenSe describe e ilustra una estructura morfológica nueva para abejas de las orquídeas (Apidae: Euglossini). Estas diminutas estructuras, aquí nombradas “estructuras yuxtaocelares”, se ubican posterolateralmente a los ocelos. Se describe la diversidad de su forma dentro de Euglossini. Estructuras homólogas fueron encontradas en algunos linajes relacionados de abejas de la familia Apidae (Anthophorini, Centridini, Eucerini), mientras que en otros las estructuras estuvieron ausentes (Xylocopinae, Nomadinae). De manera relevante las estucturas yuxtaocelares se hallan apomórficamente ausentes en todas las otras tribus de abejas con corbícula (Bombini, Meliponini, Apini, Electrobombini, Electrapini y Melikertini), lo cual concuerda con hipótesis filogenéticas actuales para este grupo.KeywordsApoidea, Anthophila, comparative morphology, Euceriti, Apiti, phylogeny