Simulations of microflows induced by rotation of spirals in microchannels

In microflows where Reynolds number is much smaller than unity, screwing motion of spirals is an effective mechanism of actuation as proven by microorganisms which propel themselves with the rotation of their helical tails. The main focus of this study is to analyze the flow enabled by means of a rotating spiral inside a rectangular channel, and to identify effects of parameters that control the flow, namely, the frequency and amplitude of rotations and the axial span between the helical rounds, which is the wavelength. The time-dependent three-dimensional flow is modeled by Stokes equation subject to continuity in a time-dependent deforming domain due to the rotation of the spiral. Parametric results are compared with asymptotic results presented in literature to describe the flagellar motion of microorganisms

Simulation-based analysis of a biologically-inspired micropump with a rotating spiral inside a microchannel

Microorganisms such as bacteria use their rotating helical flagella for propulsion speeds up to tens of tail lengths per second. The mechanism can be utilized for controlled pumping of liquids in microchannels. In this study, we aim to analyze the effects of control parameters such as axial span between helical rounds (wavelength), angular velocity of rotations (frequency), and the radius of the helix (amplitude) on the maximum timeaveraged flow rate, maximum head, rate of energy transfer, and efficiency of the micropump. The analysis is based on simulations obtained from the three-dimensional timedependent numerical model of the flow induced by the rotating spiral inside a rectangular-prism channel. The flow is governed by Navier-Stokes equations subject to continuity in timevarying domain due to moving boundaries of the spiral. Numerical solutions are obtained using a commercial finiteelement package which uses arbitrary Lagrangian-Eulerian method for mesh deformations. Results are compared with asymptotic results obtained from the resistive-force-theory available in the literature

El Impacto de las Actividades de Educación Ambiental en la Conciencia Ambiental y las Expresiones Visuales de los Estudiantes de Primaria

The aim of this research is to improve environmental awareness in primary school students. For this purpose, the study was carried out within the scope of action research pattern from qualitative research patterns. The study group was determined by selecting easily accessible samples. The study group consisted of second year students attending a state primary school in Gungoren District of Istanbul in the 2018-2019 academic year. The data of the study were obtained by the students’ environmental pictures, observation forms and semi-structured interview forms. The data obtained were analyzed by content analysis. According to the findings of the research, it is determined that students who received environmental education, draw pictures enthusiastically and reflecting environmental awareness, also after interviews students gain awareness toward environment, empathized with nature and draw highly esthetically appreciated pictures.El objetivo de esta investigación es mejorar la conciencia ambiental en los estudiantes de primaria. Para este propósito, el estudio se realizó dentro del alcance del patrón de investigación-acción a partir de patrones de investigación cualitativa. El grupo de estudio se determinó seleccionando muestras de fácil acceso y consistió en estudiantes de segundo año que asistieron a una escuela primaria estatal en el distrito Gungoren de Estambul en el año académico 2018-2019. Los datos del estudio fueron obtenidos por las imágenes ambientales, los formularios de observación y los formularios de entrevista semiestructurados de los estudiantes. Los datos obtenidos fueron analizados por análisis de contenido. De acuerdo con los resultados de la investigación, se determina que los estudiantes que recibieron educación ambiental, hacen dibujos con entusiasmo y reflejan la conciencia ambiental, también después de las entrevistas, los estudiantes adquieren conciencia hacia el medio ambiente, empatizan con la naturaleza y dibujan imágenes muy apreciadas estéticamente

Belvermeye dayalı nano konumlandırıcının simulasyon tabanlı yapısal analizi

Nano konumlandırıcılar günümüzde giderek artan bir hızla, bir çok alanda kullanılan ve ihtiyaç duyulan cihazlardır. Nano konumlandırıcıların üretiminde kullanılan mevcut üretim sistemleri birden fazla parçanın montajına dayalı karmaşık yapıların kullanılmasını gerektirmektedir. Bu nedenle üretilen konumlandırıcıların duyarlılığı üretimdeki aşamalara ve montajın hassasiyetine doğrudan bağlıdır. Bu boyutlardaki uygulamalarda montajın hassasiyeti çok ciddi sorunlar teşkil etmektedir

Examination of the budgets used to financing of Turkey’s forestry sector on basis of the General Directorate of Forestry

Ormanların ekim ya da dikim yoluyla tesis edilmesi, her türlü zararlılara, orman yangınlarına ve yasa dışı müdahalelere karşı korunması, geliştirilmesi, bakımı, ıslahı, gençleştirilmesi ve ormanlardan çok yönlü ve sürekli olarak faydalanılması gibi ormancılık faaliyetlerinin gerçekleştirilebilmesi için finansman gerekli olmaktadır. Ormanlar ekonomik olarak doğrudan gelir sağlamayan birtakım faydalar da sağlamaktadır. Ormanların ekolojik, sosyal ve koruyucu fonksiyonlarının sağladığı faydaların pazar değerinin hesaplanması oldukça zordur. Bu nedenlerle ormancılığın finansmanı bütçe kaynaklarından ayrılan paylarla da yürütülmeye çalışılmaktadır. Bu çalışma ile Orman Genel Müdürlüğü temelinde kullanılan bütçelerin gereği ve bu bütçelerin Orman Genel Müdürlüğü finansmanındaki paylarının yüzde çözümlemeleri yardımıyla hesaplanması ve mal ve hizmet üretimindeki etkinliğinin değerlendirilmesi amaçlanmaktadır. Bununla birlikte, çalışmada Orman Genel Müdürlüğü 2013, 2014 ve 2015 yıllarına ait döner sermaye bütçesi ve özel bütçe verileri kullanılmıştır. Yapılan yüzde çözümlemeleri neticesinde; çalışma yıllarını kapsayan üç yılın ortalamasına göre; Orman Genel Müdürlüğü toplam bütçe kaynağının %51’ini işletme yönetimi ve pazar gereklerine göre işleyen döner sermaye bütçesi oluştururken, %49’unu ise kamu yönetimi ve yararını esas alan özel bütçenin oluşturduğu görülmüştür. Çalışma yıllarının ortalamasına göre; Orman Genel Müdürlüğü bütçe kaynağının çoğunluklu kısmını oluşturan döner sermaye bütçesini oluşturan; brüt satışlar, diğer faaliyetlerden olağan gelir ve karlar ve olağan dışı gelir ve karlar alt kalemlerin döner sermaye bütçesi toplam geliri içindeki ağırlıkları sırasıyla %97.1, %1.5 ve %1.4 olarak belirlenmiştir. Bunun yanında, özel bütçeyi oluşturan öz gelirler ve genel bütçeden ayrılan paylar alt kalemlerinin özel bütçe toplam geliri içindeki ağırlıkları sırasıyla %50.3 ve %49.7 olarak tespit edilmiştir. Bu çalışma ile ormancılık sektörünün ekonomik sürekliliğini sağlayabilmesi noktasında ormancılık sektörüne genel bütçeden aktarılan payların artması gerekmekte gibi öneriler getirilmiştir.Financing is required for forestry activities such as the protection against all kinds of pests, forest fires and illegal interventions, establishment, development, maintenance, rehabilitation and rejuvenation of forests through sowing or planting and versatile and continuous utilization of forests. Forests also provide some economic benefits that do not directly lead to income. Calculation of the market value of the benefits provided by the ecological, social and protective functions of forests is very difficult. For these reasons, the financing of forestry is being tried to be carried out with the shares allocated from the budgetary sources. The purpose of this study to determine the necessity of the budgets used on the basis of General Directorate of Forestry, calculation of the share of these budgets in General Directorate of Forestry financing with the help of percentage solutions and evaluation of the effect of production of goods and services of these budgets. However, the revolving capital budget and special budget data for General Directorate of Forestry 2013, 2014 and 2015 were used.As a result of the percent analysis; according to the average of three years covering the working years; While the revolving capital budget, which processes according to business management and market requirements, created 51% of General Directorate of Forestry total budget resources, special budget based on public administration and benefit constitutes 49% of its. The ratios of the revolving capital budget sub-items which gross sales, ordinary income and profits from other activities, and extraordinary income and profits, within the revolving capital budget total income were determined as 97.1%, 1.5% and 1.4%, respectively. The ratios of the special budget sub-items which self-income and shares allocated from the general budget, within the special budget total income were determined as 50.3% and 49.7%, respectively. With this study, it was suggested such as the shares transferred to the forestry sector from the general budget should be increased in order to ensure the economic sustainability of the forestry sector

The significance of the furniture and other manufactured goods sector in Turkish economy

Bir ülkede genel ekonomik yapıyı ve bu yapıyı oluşturan tüm sektörlerin birbirleriyle olan ilişkilerini analitik olarak ortaya çıkarmak için girdi-çıktı çözümlemelerinden yararlanılmaktadır. Bu çalışma ile girdi-çıktı çözümlemesi yardımıyla 2012 yılı itibariyle Türkiye ekonomisini oluşturan 64 sektörden biri olan mobilya ve diğer mamul eşyalar sektörünün; üretim, katma değer, ihracat, ithalat ve diğer sektörlerle olan ilişkilerini ortaya çıkarmak ve böylece bahse konu sektörün ülke ekonomisi içerisindeki önemini belirlemek amaçlanmıştır. Araştırma neticesinde, mobilya ve diğer mamul eşyalar sektörünün; Türkiye ekonomisini oluşturan 64 sektör içinde üretim yönü ile 20., katma değer yönüyle 47., ithalatta 17. ve ihracatta da 13. sırada yer aldığı ve ihracatının ithalatı karşılama oranının ülke ekonomisi ortalamasının çok üzerinde olduğu görülmüştür. Bunlara ek olarak, Türkiye ekonomisini oluşturan sektörlerin ileri ve geri bağlantı oranı ortalamasına (0.44) göre, mobilya ve diğer mamul eşyalar sektörünün ileri (0.11) ve geri bağlantı (0.38) oranlarının düşük olduğu sonucuna da ulaşılmıştır.Input-output analysis is used to analytically expose the general economic structure in a country and the relations with each other of all sectors constituting this structure. The objective of the present study is to identify the relationships of the Furniture and other manufactured goods sector, which is one of the 64 sectors as of 2012 forming the Turkish economy, with manufacturing, value added, exports, imports and other industries and thus to determine the significance of the mentioned sector in the national economy. As a result of the research has been observed production of Furniture and other manufactured goods sector is ranked 20th in the production of 64 sectors constituting Turkey production and the value-added of this sector is ranked 47th in the value-added of 64 sectors. According to the results of the survey, the ratio of the exports to imports in this sector, which ranks 17th in imports and 13th in exports in the 64 sector economy, is much higher than the average of the country's economy. Determined in addition to these, according to the average of forward and backward links ratio (0.44) of the sectors that constitute the country's economy, the furniture and other manufactured goods sector's forward (0.11) and backward (0.38) links ratio are low

Outcomes from elective colorectal cancer surgery during the SARS-CoV-2 pandemic

This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic

El Impacto de las Actividades de Educación Ambiental en la Conciencia Ambiental y las Expresiones Visuales de los Estudiantes de Primaria

The aim of this research is to improve environmental awareness in primary school students. For this purpose, the study was carried out within the scope of action research pattern from qualitative research patterns. The study group was determined by selecting easily accessible samples. The study group consisted of second year students attending a state primary school in Gungoren District of Istanbul in the 2018-2019 academic year. The data of the study were obtained by the students’ environmental pictures, observation forms and semi-structured interview forms. The data obtained were analyzed by content analysis. According to the findings of the research, it is determined that students who received environmental education, draw pictures enthusiastically and reflecting environmental awareness, also after interviews students gain awareness toward environment, empathized with nature and draw highly esthetically appreciated pictures.El objetivo de esta investigación es mejorar la conciencia ambiental en los estudiantes de primaria. Para este propósito, el estudio se realizó dentro del alcance del patrón de investigación-acción a partir de patrones de investigación cualitativa. El grupo de estudio se determinó seleccionando muestras de fácil acceso y consistió en estudiantes de segundo año que asistieron a una escuela primaria estatal en el distrito Gungoren de Estambul en el año académico 2018-2019. Los datos del estudio fueron obtenidos por las imágenes ambientales, los formularios de observación y los formularios de entrevista semiestructurados de los estudiantes. Los datos obtenidos fueron analizados por análisis de contenido. De acuerdo con los resultados de la investigación, se determina que los estudiantes que recibieron educación ambiental, hacen dibujos con entusiasmo y reflejan la conciencia ambiental, también después de las entrevistas, los estudiantes adquieren conciencia hacia el medio ambiente, empatizan con la naturaleza y dibujan imágenes muy apreciadas estéticamente

The Impact of Environmental Education Activities on Primary School Students’ Environmental Awareness and Visual Expressions

The aim of this research is to improve environmental awareness in primary school students. For this purpose, the study was carried out within the scope of action research pattern from qualitative research patterns. The study group was determined by selecting easily accessible samples. The study group consisted of second year students attending a state primary school in Gungoren District of Istanbul in the 2018-2019 academic year. The data of the study were obtained by the students’ environmental pictures, observation forms and semi-structured interview forms. The data obtained were analyzed by content analysis. According to the findings of the research, it is determined that students who received environmental education, draw pictures enthusiastically and reflecting environmental awareness, also after interviews students gain awareness toward environment, empathized with nature and draw highly esthetically appreciated pictures.El objetivo de esta investigación es mejorar la conciencia ambiental en los estudiantes de primaria. Para este propósito, el estudio se realizó dentro del alcance del patrón de investigación-acción a partir de patrones de investigación cualitativa. El grupo de estudio se determinó seleccionando muestras de fácil acceso y consistió en estudiantes de segundo año que asistieron a una escuela primaria estatal en el distrito Gungoren de Estambul en el año académico 2018-2019. Los datos del estudio fueron obtenidos por las imágenes ambientales, los formularios de observación y los formularios de entrevista semiestructurados de los estudiantes. Los datos obtenidos fueron analizados por análisis de contenido. De acuerdo con los resultados de la investigación, se determina que los estudiantes que recibieron educación ambiental, hacen dibujos con entusiasmo y reflejan la conciencia ambiental, también después de las entrevistas, los estudiantes adquieren conciencia hacia el medio ambiente, empatizan con la naturaleza y dibujan imágenes muy apreciadas estéticamente