Analysis of the Effect of Circular Ring Baffles in Suppressor on Flow Field and Far Field Noise Levels at 9 mm Semi Automatic Pistol

A firearm generates complex phenomena in muzzle flow and modelling the flow field around the projectile has great importance on high-intensity noise prediction. The negative effects of noise can be reduced using a suppressor which can be internally or externally attached to the barrel of a firearm. The purpose of this paper is to numerically and experimentally investigate the effect of the number and distance of circular ring baffles in the suppressor on the flow field and far field noise levels. Calculations were carried out in two-dimensional, axisymmetric, transient conditions and Ffowcs Williams and Hawkings acoustic analogy (FW-H) equations were solved to predict the far field noise. Nine cases including a gun without a suppressor, a suppressor without baffles, one, three, and five baffles which were placed at 20 mm intervals from the suppressor inlet, and one, three, five, seven, and nine baffles which were placed with equal intervals in the suppressor were simulated and compared; generations of noise during the shooting process were analyzed. The results showed that in the case without a suppressor, the peak sound pressure level was 156.1 dB at a 2.5 m distance, while this value decreased by nearly 7.6% in the case of the suppressor with seven baffles which has an average value of 144.2 dB. The results obtained here may provide a beneficial reference for predicting the muzzle noise and optimizing the number of baffles in the suppressor for small caliber gun systems

Bölgesel İnovasyon Sistemleri: Başarı Koşulları ve Politika Çıkarımları

Innovation system approach, as a result of change in understanding of the innovation process, can be examined in sectoral, regional and national level. Regional innovation system initiatives which aim at increasing the innovative capacity regions have been implemented in the West for a long time. Examining the successful cases and defining the success factors of past experiences will shed light on new efforts on establishing regional innovation systems. In Turkey, efforts of building regional innovation systems have recently increased. This study aims to provide several policy recommendations on the successful formation and implementation of regional innovation systems with the help of Western experiences. In the study, the concept of regional innovation system is examined in detail in terms of its emergence, elements, success conditions and policies. As a result of the study, it is concluded that four factor became prominent in building regional innovation system and gaining regional competitive advantage. These factors are (i) region-specific sectoral clusters, (ii) local and global networks, (iii) education/science infrastructure and links with university, and (iv) entrepreneurship supporting policies

Coğrafi Yakınlık 'Hala' Önemli mi ? Mekansal İnovasyon Modellerinden Çok-Yerelli Bilgi Dinamiklerine Dönüşüm

Especially during the last 15-20 years, economists, economic geographers and planners dealing with regional development have devoted the large portion of their time to seeking a "new" model. The concepts which are developed in regional development focus on geographic proximity as a pioneering factor of innovation. However, “new” theories highlight the increased mobility of knowledge and the transfer of knowledge between long-distance places. Therefore, in addition to intra-regional networks, long distance and inter-regional Networks have also played a critical role. In this study, the increasing importance of innovation-knowledge economy and the growing literature on network theory will be discussed. Firstly, the concepts of industrial zones, innovative environment, clusters, regional innovation systems and learning regions which can be defined as "Territorial Innovation Models" will be examined. Then, whether the “geographical” proximity is still important will be discussed in parallel with the transformations of innovation, knowledge and regional development and long distance interactions will be mentioned in terms of the new theories

Bölgesel İnovasyon Sistemleri: Başarı Koşulları ve Politika Çıkarımları

Innovation system approach, as a result of change in understanding of the innovation process, can be examined in sectoral, regional and national level. Regional innovation system initiatives which aim at increasing the innovative capacity regions have been implemented in the West for a long time. Examining the successful cases and defining the success factors of past experiences will shed light on new efforts on establishing regional innovation systems. In Turkey, efforts of building regional innovation systems have recently increased. This study aims to provide several policy recommendations on the successful formation and implementation of regional innovation systems with the help of Western experiences. In the study, the concept of regional innovation system is examined in detail in terms of its emergence, elements, success conditions and policies. As a result of the study, it is concluded that four factor became prominent in building regional innovation system and gaining regional competitive advantage. These factors are (i) region-specific sectoral clusters, (ii) local and global networks, (iii) education/science infrastructure and links with university, and (iv) entrepreneurship supporting policies

Bölgesel Politika Ekseninde Yaşanan Dönüşüm: Türkiye’de Kalkınma Planlarında Bölgesel Politikaların Değişimi

Bu çalışmanın amacı küreselleşme-yerelleşme eğilimlerine koşut olarak bölgesel politikalarda yaşanan dönüşümleri incelemektir. Bu çerçevede yaşanan dönüşümlerin Türkiye’deki kalkınma planlarının bölgesel politikalarında yarattığı değişimleri (planlarındaki yansımalarını) ortaya çıkarmaktır. Çalışma kapsamında, 1963-2007 yılları arasında uygulamaya koyulan (ve sonuncusu halen uygulanmakta olan) dokuz kalkınma planında yer alan bölgesel politikalar ve bu politikaların yeni teorileri ne ölçüde takip ettiği değerlendirilmektedir

Coğrafi Yakınlık 'Hala' Önemli mi ? Mekansal İnovasyon Modellerinden Çok-Yerelli Bilgi Dinamiklerine Dönüşüm

Especially during the last 15-20 years, economists, economic geographers and planners dealing with regional development have devoted the large portion of their time to seeking a "new" model. The concepts which are developed in regional development focus on geographic proximity as a pioneering factor of innovation. However, “new” theories highlight the increased mobility of knowledge and the transfer of knowledge between long-distance places. Therefore, in addition to intra-regional networks, long distance and inter-regional Networks have also played a critical role. In this study, the increasing importance of innovation-knowledge economy and the growing literature on network theory will be discussed. Firstly, the concepts of industrial zones, innovative environment, clusters, regional innovation systems and learning regions which can be defined as "Territorial Innovation Models" will be examined. Then, whether the “geographical” proximity is still important will be discussed in parallel with the transformations of innovation, knowledge and regional development and long distance interactions will be mentioned in terms of the new theories

Türkiye’de İş Geliştirme Merkezlerinde (İŞGEM) Yer Alan Kiracı Firmaların Hayatta Kalma Performansı

The aim of this study is to examine the effects of business incubator programs and its services on tenant firm performance. In this context, the effect of business incubator services on firms’ survival was examined through the case of Turkey’s Business Development Centers (İŞGEMs). The scope of this research consist of 414 firms, 238 firms which exist in incubators located in Adana, Diyarbakır, Elazığ, Ereğli, Eskişehir, Mersin, Nevşehir, Samsun, Tarsus, Van, Yozgat and Zonguldak İŞGEMs and 176 firms which left these incubators before. Within the framework of research model, business incubator services were categorized as (1) office services, (2) shared/common services, (3) education/training services and (4) counseling services and include total of 22 sub-services. As a research methodology, Kaplan-Meier survival estimates were used. As a result of the research models, it was concluded that all service groups have significant and positive effects on firms’ survival probabilities

İşletme Kuluçkaları ve Bölgesel Kalkınma: Kavramsal Çerçeve ve Literatür Bulguları

There are many support mechanisms for supporting newly established firms. Business incubators, one of them, are generally focused on supporting and promoting entrepreneurship, increasing employment through creating new job opportunities, enhancing local, regional and national R&D and innovativeness. The term of “incubator” is used to define supporting institutions to growth and survival of new firms. Business incubators are becoming a basic component of regional and national economic development strategies in many countries. In this study, the importance of business incubators in terms of local and regional economic development is discussed. Firstly, the concept of “business incubator” will be examined in terms of theoretical and conceptual perspective. Secondly, the importance of business incubators for regional development will be mentioned. Then, some recommendations based on the findings of the literature will be presented for using business incubators as a tool for regional development

İşletme Kuluçkaları ve Bölgesel Kalkınma: Kavramsal Çerçeve ve Literatür Bulguları

There are many support mechanisms for supporting newly established firms. Business incubators, one of them, are generally focused on supporting and promoting entrepreneurship, increasing employment through creating new job opportunities, enhancing local, regional and national R&D and innovativeness. The term of “incubator” is used to define supporting institutions to growth and survival of new firms. Business incubators are becoming a basic component of regional and national economic development strategies in many countries. In this study, the importance of business incubators in terms of local and regional economic development is discussed. Firstly, the concept of “business incubator” will be examined in terms of theoretical and conceptual perspective. Secondly, the importance of business incubators for regional development will be mentioned. Then, some recommendations based on the findings of the literature will be presented for using business incubators as a tool for regional development

Experimental Investigation of the Projectile type on Sound Pressure Levels Fired with 9 mm Gun

Throughout of the firing process, too much noise is occurred in the form of an blast wave caused by the discharged gas. An instantaneous and high amplitude sound pressure is created by the explosion and this pressure causes a harmful noise to the human ear. The main sources of the generated sound can be categorized as the explosion at the barrel exit, projectile velocity and the sound produced when the projectile hits the target. Subjects such as subsonic and supersonic projectiles, projectiles with different geometries, silencer systems are very important to reduce this explosion noise created by gun systems. Within the scope of this study, the peak sound pressure levels after firing the subsonic and supersonic projectiles from a 9 mm gun were experimentally measured at different positions. The measurements were realized at 23 different positions. The results of this study showed that in all measurement positions, supersonic projectiles have higher peak sound pressure levels (db) than subsonic projectiles. The peak sound pressure levels decreased with increasing distance from the gun barrel exit a as expected. Also, it has been determined that subsonic and supersonic projectiles give close results to each other in the measurements made at the same level with the barrel at y-axis direction