Gölgeleme araçlarının mekânın toplam soğutma yükleri açısından etkinliklerinin belirlenmesi

During most hot period it is possible to obtain passive cooling by decrease of surface temperatures with airflow velocities caused by wind, entering interior with the effect of pressure difference through the openings during the time intervals when the outside air is cooler than interior. This effect turns inversed when the outside air temperature is more than interiors. Shading devices used to protect from unwanted solar radiation acting on interior surfaces change the airflow effects acting interiors according to their types. The changes in volume flow rates, interior velocities and solar radiation amount can be advantageous or disadvantageous for total cooling loads according to the time interval as the interior and outside temperatures changes through the day.  Determination of the combined effect of shading device efficiency through solar radiation protection strategy and natural ventilation, will give opportunity of designing optimum shading device. In validation of shading device efficiency with different types of shading device alternatives, zone gains and losses with convection, zone sensible gain and losses with ventilation, zone gains from windows and total cooling loads through specific time intervals are compared. Cooling load calculations are run through energy analysis simulation program Energyplus using heat balance calculation method. Convection coefficients, exhibiting the effects of the interior velocities which change by shading devices are calculated by using the datas of velocity measurements performed on wind tunnel with a model with 4 different types of shading device and without shading device. Heat gain from opaque interior surfaces by the effect of solar radiation are considered in Energyplus with the output of heat gain to air by convection. As opening dimensions are directly related to volume flow rates, required in calculation of sensible heat gains of zone by ventilation, it  is expressed by discharge coefficients obtained by measured velocities on wind tunnel in front of the model and pressure differences between front and back openings for all alternatives. Shaded and unshaded areas occuring by solar radiation acting on facade with different shading device alternatives are considered. All these parameters of shading devices are used in Energyplus cooling load calculation process. For every alternatives 4 simulations of cooling load calculations had been done for open window and closed window in order to emerge the effects of airflows and solar radiation effects through specific times changing by effects of shading devices. The situations with shading device alternatives are classified as follows; Closed window, no shading device, 1SİM3kap.pen; with shading device, parallel to facade with 90ο slat angle parallel to ground, 2.1SİM5kap.pen; parallel to facade with 45ο slat angle parallel to ground, 2.2SİM9kap.pen; perpendicular to facade with 90ο slat angle parallel to facade, 3.1SİM12kap.pen; perpendicular to facade with 45ο slat angle parallel to facade, 3.2SİM15kap.pen, Open window, with no shading device, 1SİM3ac.pen; with shading device, parallel to facade with 90ο slat angle parallel to ground, 2.1SİM5ac.pen; parallel to facade with 45ο slat angle parallel to ground, 2.2SİM9ac.pen; perpendicular to facade with 90ο slat angle parallel to facade, 3.1SİM12ac.pen; perpendicular to facade with 45ο slat angle parallel to facade,  3.2SİM15ac.pen,  The effects of shading devices on total cooling loads and 3 gain components  are evaluated through the time intervals of 01:00-07:00, 08:00-18:00, 19:00-24:00 during the day. 4 simulations of cooling load are made for the situation with no shading device and shading device. In the 1. simulation run for closed window (1SİM3kap.pen, 2.1SİM5 kap.pen, 2.2SİM9kap.pen, 3.1SİM12 kap.pen, 3.2SİM15kap.pen) and 2. Simulation for open window (1SİM3ac.pen, 2.1SİM5ac.pen, 2.2SİM9 ac.pen, 3.1SİM12ac.pen,3.2SİM15ac.pen); Zone’s hourly gain by convection from interior surfaces, Zone’s hourly gain and loss by ventilation; Zone’s hourly gain and loss from window; Zone’s total cooling load, are obtained.3 and 4. simulations of cooling load are made for the situation without shading device and with shading device for open and closed window  in order to get interior mean air and surface temperatures. The average results of total cooling load, infiltration sensible gain, convection to air rate, window heat gain through these hours are compared with no shading device situation by summing the results through 01:00-07:00, 08:00-18:00, 19:00-24:00time intervals. Keywords: Shading device, natural ventilation, total cooling load.Isıtmaya gereksinim duyulmayan dönemlerde (ESD) güneşin istenmeyen ısıl etkilerinden korunmak üzere gölgeleme araçları kullanılmaktadır. Dış hava sıcaklığının iç hava sıcaklığından az olduğu saatlerde, açıklıklardan rüzgâr basıncı ile içeri giren hava akımlarının etkisi ile yüzeyden ısı taşınımıyla soğutma sağlamak mümkündür. Bu etki dış hava sıcaklığının iç hava sıcaklığından yüksek olduğu saatlerde tersine dönmektedir. Güneşin açılarına göre farklı tipte tasarlanan gölgeleme araçlarının hem doğal havalandırma hem de güneş korunumuna bağlı bileşik etkinliğinin değerlendirilmesi ile optimum gölgeleme aracı tasarlamak mümkün olacaktır. Gölgeleme araçlarının gün içerisinde farklı zaman aralıklarında etkinliğinin değerlendirilmesinde; farklı tipte gölgeleme aracı takılı durumda, ortamın yüzeylerden taşınım yolu ile kazanım, havalandırma yolu ile hissedilen kazanım, pencerelerden kazanım bileşenlerinin ve mekânda oluşan toplam soğutma yüklerinin gün içerisinde belirli zaman aralıklarındaki ortalamaları karşılaştırılmıştır. Soğutma yükü hesapları ısı dengesi hesap yöntemini kullanan Energyplus programında yürütülmüştür. Ortamın yüzeylerden taşınım yolu ile kazanımlarının hesaplanmasında gölgeleme araçları ile değişen iç hava hareketi hızlarının etkisini ortaya koyan ortalama taşınım katsayıları rüzgâr tünelinde gölgeleme araçsız ve 4 farklı tipte gölgeleme aracı takılı durum için bina modeli içinde gerçekleştirilen hız ölçüm bulguları ile hesaplanmıştır. Güneş yolu ile iç opak yüzeylerin ısı kazanımları da bu bileşen içinde göz önüne alınmıştır. Ortamın havalandırma yolu ile hissedilen kazanımlarının hesaplanmasında gereken hacimsel debi miktarları gölgeleme araçları takılı durumda model ön ve arka yüzeyinde ölçülen basınçlar, hızlar, boşaltım katsayıları ve gölgeleme araç tiplerine göre değişim gösteren açıklık alanları ile bulunmuştur. Pencereden kazanımlarda dış yüzeyde oluşan gölgeli ve gölgesiz alanlar göz önüne alınmıştır.Anahtar Kelimeler: Gölgeleme araçları, doğal havalandırma, soğutma yükü

The effect of the building façades openings on airflow in courtyards

Rüzgar, yerleşme ve bina tasarımında eski çağlardan beri önemli bir çevresel faktör olmuştur. Rüzgarın, yapıların soğutma yüküne etkisi, bu etkilerin bilimsel yöntemlerle ortaya konması, tasarım ve uygulama alanlarına zaman geçirilmeden yansıtılması enerji tasarrufuna her zamankinden daha fazla gereksinim duyulan günümüzde, çok büyük önem taşımaktadır. Bu bağlamda, avlulu binalarda rüzgar etkisi ile oluşacak hava hareketinin etkinliğini değiştirebilecek binaya ait diğer açıklıkların da göz önünde bulundurulması, dikkatlice incelenmesi gerekmektedir. Hava hareketlerine, bir pasif iklimlendirme aracı olarak özellikle sıcak ve nemli iklim kuşaklarında, bina içi havalandırmanın sağlanması açısından gereksinim duyulabilir. Sıcak-kuru iklim bölgelerinde doğal taşınım yoluyla oluşacak bina içi-avlu arası hava akımları, ılımlı-nemli ve sıcak-nemli iklim bölgelerinde rüzgar basıncı yardımı ile elde edilmektedir. Avlulu binaların özellikle sıcak kuru dışında ılımlı veya sıcak nemli iklimsel karakter gösteren bölgelerde doğal havalandırma açısından performansını arttıracak, dolaylı olarak soğutma yükünü azaltacak değişikliklerden biri avlu mekanına yatay doğrultuda rüzgarın iteceği havayı geçirecek boşlukların yaratılmasıdır. Bu çalışma avlulu yapıların mimari kütlesinde yaratılacak açıklıkların avlu mekanındaki hava hareketleri hızına etkilerini rüzgar tüneli deneyleriyle ortaya koymaktadır. Elde edilen sonuçlar; boşluksuz avlulu binaya göre farklı şekillerde düzenlenen açıklıkları olan binalarda, düşey yüzeylerdeki boşlukların alan ölçüsü ve konumlarıyla orantılı olarak avlu içerisindeki hava hareketi hızlarını arttırmakta olduğunu göstermektedir.  Anahtar Kelimeler: Doğal havalandırma, bina içi hava hareketleri, rüzgar etkileri, pasif soğutma, avlulu bina iklimi.One of the modifications to increase the performance of the buildings with courtyard by means of ventilation and decrease the cooling load indirectly in the regions especially temperate or hot-humid climate except hot-dry is to create cavities to convey the air horizontally compelled in the courtyard by the wind. The air movement as a passive air-conditioning media may be required in order to provide in-building ventilation especially in the hot-humid climate zones. In hot-dry climates, the traditional courtyard building form ensures air flows to arise by themselves through natural ventilation between a building and its inner court, while in temperate-humid and hot-humid climates, such air flows are created by using the wind pressure. The courtyard building form should be improved by means of modifications designed to increase its performance of ventilation, especially for other hot climate regions than the hot-arid climate regions. In this context, the other openings pertaining to the building which may change the air movement effectiveness incurred with the wind effect in the buildings with courtyard should be taken into consider and studied carefully. Many numerical or experimental studies have been conducted on the insulation aspects of courtyard buildings. However, only a limited number of studies have been conducted on the wind effects. When a building contains openings, the air flows reach highest velocity in the openings made in the same direction as the wind. The results in question comply with a number of similar experiments. The courtyard depth in the building without opening makes an effective variable in controlling these events. However, except for the hot-arid climates, the openings to be arranged on perpendicular surfaces with the buildings with courtyards to be built especially in hot-humid and temperate-humid climate regions will be of great importance. The steps of the experimental study consist of the setting up of the experiment mechanism, designation of the reference building mass, scale model making, determination of the model building configurations, designation of measurement point positions and numbers, performing the measurement visualization of the outputs and interpreting the results in short. Consequently, the air flow in the courtyard not only circulates through up and down wind zones, but also circulates through the lateral areas. An air inlet opening located in the middle of the courtyard and an opening located in the middle of the lateral area of the courtyard cause the air flow to change direction in an abrupt way after moving into the courtyard, so that the air flow turns to the air outlet opening located on the lateral wall. Thus the air flow does not reach to high velocities in the wind direction within the courtyard. Results of the studies on the effects imposed by openings arranged in the mass of courtyard building, depending on said openings' positions towards the wind and their surface area rates, on the average velocity of the air flow occurring in the courtyard, can be summarized as follows. Contribution of the openings situated on the lateral faces extending in parallel with the wind within the courtyard to increase the velocity is less than the contribution of the openings situated on the upwind and downwind surfaces. In other words, for arrangements where the courtyard openings' areas are equal, average speeds are lower in choices where openings are situated on the lateral surfaces only. For choices with equal total opening areas, the ones having openings on their lateral surfaces and distributed on all upwind and downwind surfaces provide lower velocities than the ones having openings in the wind direction only. This study explains the effects imposed by openings, which will be created in the architectural mass of courtyard buildings, upon the velocities of air flows within such courtyards, through tests conducted in a wind tunnel. The results of this study indicate that for buildings containing openings arranged in different configurations from those of courtyard buildings, the openings located on perpendicular surfaces increase the velocities of air flows within courtyards in proportion with their dimensions and positions. Keywords: Natural ventilation, In-building air movements, Wind effects, Passive cooling, Climate of buildings with courtyard.

Effect of shading devices on external pressure coefficients' of windvard surfaces of buildings

Binaların pasif olarak en etkin biçimde soğutulması amaçlandığında; güneş ışınımı engeli olarak tasarlanacak kontrol elemanlarının (GE), tasarım aşamasında rüzgar etkileri bakımından irdelenerek performanslarının optimize edilmesi zorunludur. Yukarıdaki gerekçeye dayanarak yapılacak çalışmanın amacı; özellikle rüzgar konusunda sayısal yöntemler yeterli olamayacağından, GE’lerin basınç ve taşınım katsayıları üzerindeki etkilerinin rüzgar tünelinde deneysel yolla ortaya konmasıdır. GE’lerin cepheye paralel, dikey ve 45 derece açılı konumlandırılışlarıyla ana üç seçenek, kanatlarının 0 – 45 - 90' kanat açılarıyla oluşturulmuş almaşıklar ve referans (BOŞ) durum da dahil olmak üzere toplam 19 adet farklı durum üretilmiştir. Seçenek ve almaşıkların her birinde tünel içi hızı (GH) 2.5 ms-1, 5.0 ms-1 ve 8.3 ms-1’de rüzgar üstü yüzeyde basınç ölçümleri yapılmıştır. Bina yüzeyinde oluşan basınç katsayılarının (Cp) GE seçeneklerine bağlı olarak referans duruma (BOŞ) göre ne kadar farklılık gösterdiği incelendiğinde; % 95 güven aralığında, en dikkate değer fark referans durum ile (GE- CP- YK 0) yatay kanatlardan oluşan gölgeleme elemanının cepheye paralel konumlandırıldığı, 0 derece kanat açısında (t = 4.745, p =.0000 düzeyinde) ortaya çıkmıştır. Yapılan çalışmanın sonuçları pasif soğutma sisteminde rüzgar basıncıyla iç mekanlardaki hava hareketi hızının uygun düzeylerde sağlanıp sağlanamayacağının kestirilebilmesinde kullanılabilecektir. BOŞ durumda orta aksta cephenin tümünde Cp ort = ~ 0.80 düzeyinde elde edilen basınç katsayısı (Cp) değeri birçok ülkenin rüzgar yüklerine ilişkin yönetmeliklerine uyum göstermesine rağmen zemine yakın noktalarda mevcut benzer çalışmalardan ~ %10 daha büyük miktarlar ortaya koymuştur. Anahtar Kelimeler: Gölgeleme elemanları, basınç katsayısı dağılımı, doğal havalandırma, pasif soğutma.Solar shading devices prohibit the passage of direct component of solar radiation at the same time decrease the chilling effect of winds on buildings by forming insulative air pockets in summer season. External solar shading devices vary as a function building crust orientation.  In other words they should be designed as auxiliary architectural parts. These parts may be manufactured from materials such as glass, wood, plastic, concrete or metal. Typologically their form resembles shield forms which are either parallel or perpendicular to the building façade. Wind imposed pressure variations have major influence on building thermal comfort through temperature, humidity and air circulation speed.  These entities vary as a function of wind direction, wind speed, building orientation, roof and façade shapes, building height and openings on winward and leeward façades.  Air mass flow rate that passes through the building may be calculated as a function of average inlet and outlet pressures. In order to obtain the effect of solar shading devices on the wind pressure field over the building surface, an experimental campaign is conducted in a wind tunnel which has a test cross section of 1x1 meter. The 4 mm thick Plexiglas building model which is 50 cm. in width, 30 cm in height and 50 cm in depth simulates 5x3x5 m full scale building forming one zone. Solar shading devices are made of aluminum and of two type wings that are placed parallel to border longitudinal or transversal. The wings make 0, 45 and 90 degrees with the device plane. The position of the shading devices that holds the wings together also makes 0, 45 and 90 degrees with respect to the vertical windward façade of the model.  Thus, including the baseline - situation unless shading device is mounted - case, 19 different configurations;   are investigated throughout the campaign. There are a total number of 105 pressure measurement points clustered around the edges on the windward face of the model. The measurements were made at 2.5 m/s, 5 m/s and 8.3 m/s average wind speeds. For the case in which solar shading devices are not attached to the façade, the Cp distributions stay in a very narrow band no matter what the wind tunnel speed is.  The minimum Cp values are recorded as 0.42, 0.38 and 0.40 for the three speeds: 2.5, 5.0 and 8.3 m/s respectively. The maximum difference between the Cp values happens to be 0.04. The pressure coefficients (Cp) data obtained for different configurations of shading devices   are compared with the baseline configuration by Paired Samples Test. They are found  significant difference in 95% confidence level, between basline case (BOS ) and  configuration  that is the shading device parallel to building surface and its wings closed (they make 0 degree with respect to the self plane ) (GE-CP-YK 0  ). The average Cp value along the central axis (Cpave ~ 0.80) obtained for basline case (BOS) is in good agreement with wind load regulations of many other countries. According to the positioning and shading intensity of opaque shading devices on the windward face, the Cp values vary between 130 % and 40% with the respect to baseline case. The correlation coefficients obtained along the C1 axis are calculated as 0.74 and 0.84 for the horizontal and vertical wing configurations respectively. The measurement points corresponding to the opening on the windward face give an average correlation coefficient of 0.73 for all configurations. The effect of Solar shading devices on building façade pressure coefficient distribution has been considered only by a few numbers of researchers in the field.  Therefore, excluding the baseline case, the results obtained in the present investigation are original data introduced to the building aerodynamics field. Air mass flow rate that passes through the building may be calculated as a function of average inlet and outlet pressures. In order to assess the usage of the results in the design of natural ventilation systems and cooling load calculations, different pressure and velocity measurement programs are being undertaken.  Keywords: Shading devices, forced convection heat transfer, wind pressure distribution, natural ventilation, passive cooling, natural  climatisation.

Revisionsplikt i små ägarledda aktiebolag : Intressenternas inställning till, och gardering mot ett eventuellt avskaffande av revisionsplikten

Debatten om ett borttagande av revisionsplikten i små och medelstora aktiebolag blev åter aktuell efter att Svenskt Näringsliv i mars publicerade en rapport i ämnet. Enligt EG-rättens fjärde direktiv kan de enskilda medlemsländerna själva besluta om revisionsplikten skall avskaffas för små aktiebolag eller inte. Inom den europeiska unionen är det endast de nordiskaländerna som har valt att ha kvar plikten. Informationen i en årsredovisning används främst av företagsintressenter för att kunna avgöra företagets ekonomiska situation. I och med att en oberoende revisor granskat årsredovisningen får intressenterna ett kvitto på att innehållet är kontrollerat och upprättat efter god redovisningssed. Problemet för intressenterna är hur de ska kunna gardera sig för att samla in tillförlitlig information för bedömning av företaget om revisionsplikten avskaffas. Vi har som syfte med denna studie att titta närmare på hur de små ägarledda aktiebolagens externa intressenter ställer sig till ett eventuellt avskaffande av revisionsplikten och vilka konsekvenser denna avskaffning kan medföra för dem. De intressenter som studeras är kreditgivare, Skatteverket, Ekobrottsmyndigheten, Svenskt Näringsliv och revisorer. Vår empiriska undersökning är uppbyggt på en kvalitativ studie som baseras på primärdata i form av intervjuer. Vi kommer i vår slutsats fram till att de flesta intressenter har ett behov av reviderade årsrapporter. Informationen i årsredovisningen fungerar som en förtroendeskapande faktor för att säkerställa att företaget kan fullfölja sina förpliktelser gentemot intressenten. Ett borttagande av revisionsplikten skulle leda till att kvalitetsstämpeln försvinner vilket ökar intressenternas kontrollbehov för att säkra tilltron till årsredovisningen.The debate about the possibilities to omit the audit duty for small and middle-sized joint-stock companies was once again actualized after Svenskt Näringsliv (Confederation of Swedish Enterprise) published a report in March 2005. In the European Union’s fourth company directive each member country can choose to omit the audit duty for small companies, however in the European Union it is only the Nordic countries that still obtain the audit duty for such companies. The information in a company’s accounting should be used by the stakeholders to ensure the economical position of the company. With a result of an independent auditor inspecting the annual report, the stakeholders get a receipt to ensure that it’s contents is controlled and follows the generally accepted accounting principles (GAAP). The problem for the stakeholders is how to make sure that they receive reliable information for estimating the company if the audit duty is omitted. Our purpose with this thesis is to investigate how the external stakeholders of small jointstock companies think about omitting the audit duty and which aftereffects this omitting can bring to the stakeholders. The stakeholders are creditors, the National Tax Board, the Swedish National Economic Crimes Bureau, the Confederation of Swedish Enterprise and auditors. Our empirical research is performed on a qualitative research approach based on personal interviews. The conclusion of this paper is that most of our stakeholders have a need for revised annual reports. The company’s audited accounting inspires confidence to its information, which guarantees that the company can complete their contractual duty against the stakeholder. An omitting of the audit duty would erase the quality receipt, which leads to an increased need of control for the stakeholders to ensure their trust to the annual reports

Evaluation of the effects of courtyard building shapes on solar heat gains and energy efficiency according to different climatic regions

The courtyard buildings, which we face either as a regulator of inter-building microclimate or as a climatic regulator at urban scale especially in hot climate regions, and which constitute one of the fundamental characteristic building styles of such climatic regions, should be applied in a form compatible with the features of the climatic region it is used. There is the need for a study that allows formation of a model toward determination of the optimum courtyard form and meeting the conditions of comfort by establishing an optimization model taking into consideration the climatic, meteorological differences for each climatic region the specific climatic region requires. The purpose of this study is to examine the energy efficiencies of the courtyard buildings used either as a micro climatic regulator in hot-dry climatic regions, or as a climatic regulator at urban scale, and to determine inter-building and courtyard comfort statuses, besides, to manifest different thermal behaviors of such buildings by estimating the same fully and accurately using real meteorological data under different design and climatic conditions with computer energy simulation on different courtyard form options put forth for different climatic regions, and thus to provide new information to designers at the process of putting forward the optimum courtyard form according to the characteristics and data of the specific climate for different climatic regions. By using the CFD program, this study has analyzed the thermal comfort statuses and energy performances of 7 different courtyard shapes in inter-courtyard and building volumes that are discussed in hot-dry, hothumid and cold climatic regions as well as the effect of the sunbeams received by the building surface and the daily solar movement on the thermal performance on the building. As a result of the entire analysis made for all building shapes, the obtained values were interpreted and the total energy performances were evaluated for each climatic region. In this study, the courtyard buildings will be assessed in terms of their thermal performances. (C) 2014 Elsevier B.V. All rights reserved

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field