Analysis of impact toughness and the critical stress intensity factor KIc in ferrite-austenite welded joints with different heat input

Introduction/purpose: Constructions always have several critical points that can be sources of possible defects. All these critical places must be taken into account in safety assessment where the most unfavorable exploitation factors are considered and the local safety of a joint is assessed. Today, joints of various compositions are becoming more frequent in metal constructions. Due to the requirements of economy and ecology, welded joints of microalloyed ferritic steels with high-alloyed austenitic steels are increasingly encountered during the construction of power plants, chemical facilities, etc. Tests of such welded joints have been performed on tanks for oil derivatives, where parts of the tank shell are made of microalloyed ferritic\ud steel and the roof structure is made of high-alloyed austenitic steel. Methods: In the paper, an experimental analysis of crack propagation in an austenitic-ferritic welded joint was performed. The welding was performed by the MIG welding process with two different heat inputs, and the same filler material MIG 18/8/6 was used. Two types of welded plates were tested. The characteristics of the base, filler and auxiliary materials and welding technologies are given. Notched test specimens with an initiated crack-type fracture were made in order to determine the impact properties and fracture mechanics parameters. The results: The research carried out within this study aimed to compare the obtained results of the impact toughness and fracture toughness at flat deformation in a ferrite-austenitic welded joint. An evaluation of the results obtained during the testing of the experimental plates welded with different amounts of heat input is also given. Conclusion: These test results established the dependence of the geometry of a propagating crack and the stress conditions for further crack propagation. It is possible to determine the values of the parameters that describe the behavior of the material, both in linear-elastic and in elastoplastic fracture mechanics

Osvrt na projektovanje glavnog rotora helikoptera / Review of the design of the helicopter rotor / Oбзор проектирования главного ротора вертолета

U radu je prikazano projektovanje glavnog rotora helikoptera uz pomoć patentne dokumentacije, kao veoma korisnog alata za dolaženje do konkretnih ideja i konstrukcija, kako bi se na najekonomičniji način pronašlo kvalitetno rešenje za određeni tehnički problem koji je prisutan u postupku konstruisanja. Veliki broj tehničkih informacija prvo se pojavljuje u patentnim dokumentima, a oko dve trećine ovih informacija ne može se naći ni na kojem drugom mestu. Prikazana je struktura patentnih dokumenata sa težištem na delovima koji se odnose na tehničke informacije sa detaljnim objašnjenjem mogućnosti primene patentne dokumentacije u toku projektovanja glavnog rotora helikoptera. Na konkretnom primeru projektovanja rotora helikoptera prikazan je postupak i načini pretraživanja patentne dokumentacije. Korišćena je Espacenet baza patentne dokumentacije, kao najobuhvatnija i najčešće korišćena baza koja sadrži preko osamdeset miliona različitih patentnih dokumenata o pronalascima i tehničkim unapređenjima iz celog sveta. Težišni deo rada odnosi se na prikaz postupka pretraživanja patentne dokumentacije radi dolaženja do rešenja tehničkog problema konstrukcije glavnog rotora helikoptera, koji se odnosi na obezbeđivanje potrebnog zabacivanja i bržeg odziva promene smeštajnog ugla (koraka) lopatice krutog rotora helikoptera. / This article - paper presents the design of the main rotor of the helicopter supported by the patent documents, as a very useful tool (instrument) to reach the specific ideas and design in order to find the most economical way for the quality solution for a certain technical problem present in the process of design (construction). A large amount of technical information first appears in patent documents and about two thirds of this information cannot be found on any other site. The structure of patent documents is presented with an emphasis on the elements that relate to technical information with the detailed explanation of the possibilities of the application of the patent documentation during the process of design of the main helicopter rotor. The procedure and methods of research of the related patent documents are presented on a specific example of helicopter rotor design. The Espacenet database of patent documents was used as the most comprehensive and the most frequently used database containing over eighty million different patent documents about inventions and technical improvement (advancement) from all over the world.The crucial part of the paper relates to the presentation of a patent search method in order to find a technical solution for the structures of the main helicopter rotor which relates to the provision of the required casting and rapid response changes of accommodation angle (step) of the rigid rotor blades of helicopters. / В работе рассмотрено проектирование главного ротора вертолета при использовании патентной документации, в качестве важнейшего инструмента поиска конкретных технических решений, что позволяет снизить экономические затраты при решении определенных конструктивных проблем. Большой объем технической информации впервые публикуется в качестве патентов, а около 2/3 невозможно найти в других источниках. Приведена структура патентной документации по разделам, с пояснениями возможности применения технических решений при проектировании главного ротора вертолета. На конкретном примере показан способ поиска по патентной базе «Espacenet», которая содержит более 80 миллионов различных патентов и является наиболее часто используемой. Основная часть работы относится к описанию процесса поиска патентных документов при решении проблемы жесткого соединения лопастей с головкой ротора и изменения угла атаки (шага) лопастей, при проектирования главного ротора вертолета

Confidential patent application with an example of preparation

In order that the invention solving a technical problem receives a patent protection, it is necessary to file a patent application. For the protection of confidential inventions which are important for defense and national security, a confidential patent application[1] must be filed. A confidential patent application is an important and complex document, the parts of which are,  in principle, exposed in an established order. For the preparation of patent applications, it is necessary to engage experts with higher education, primarily in the technical field the invention relates to. The contents of the patent application is a basis for examining whether the application meets the requirements for patentability and whether the right to patent protection is achieved. Besides theoretical discussions on patent application, the paper gives a short version of an example of an application regarding a protected confidential invention. Introduction The basic condition for the exercise of patent protection is filing a patent application, the test procedure and, eventually, depending on the test results - the recognition or rejection of the patent. The paper gives a description of all parts of the patent application on an example of a confidential invention already patented. The content of the confidential patent application The confidential patent application for confidential invention protection consists of the following parts: The application for a patent; description of the invention; the claims (indication of what is new and what is required to be protected by patenting); abstract (short summary of the invention)  and a draft of the invention (to which the description and the claims are referred). The application for a patent The application for patent is filed on Form P-1 and a request for the petty patent on Form MP-1. The data entered in the file is, for example: the applicant; the lawyer; the name of the invention in Serbian and English; the inventor; the rest of the patent application, etc.. Description of the invention The description of the invention aims to provide sufficient technical data and to further clarify and describe all the details of the invention for which protection is sought in the claims. The description should enable the average expert in the specific field of technology to perform  or to conduct a  procedure on the application and determine whether it meets the requirements for patentability. The description contains the following units: title of the invention; technology field; technical problem; state of technology; brief summary of the invention; a brief description of the figures of the draft; detailed invention description and the methods of industrial and other applications of the invention. The claims The claims are the most important part of the patent application and all other elements of the patent application are in a function of patent claims. The claims must define the invention solely by its technical characteristics. They are submitted on a separate sheet after the description of the invention under the title "The claims". Depending  on the protection sought, one or more claims can be placed. Abstract The abstract contains the title of the invention and a brief summary of the invention as shown in the description, the requirements and the draft. A brief review must indicate the technical field to which the invention relates and must allow a clear understanding of the technical problem, the essence of the problem and the basic way (ways) of using the invention. The abstract contains a maximum of 150 words. Draft of the invention A draft of the invention is submitted on separate sheets, along with the title of the invention on each side. The reference signs given in the description, requirements and the draft must be the same throughout the application. Other documents with the patent application In addition to the above mentioned sections of the patent application, the following is submitted: power of attorney; cofirmation on presenting the invention at an international exhibition; certified copy of the first patent application; statement on the basis of entitlement to file an application; statement by the inventor if he does not want to be mentioned in the patent application; proof of the payment of the patent application fee; statement of a joint representative if there are more applicants. Conclusion In order that a confidential invention receive  patent or petty patent protection, it is necessary to file a patent application. A confidential patent application is a very comprehensive document which has to be compiled with expert knowledge from both the technical field to which the application relates and the field of intellectual property protection. The shown content of the confidential patent application with an example can be useful for inventors in their attempts to draw up their own patent applications. [1] The structure and the content of a confidential patent application  is identical  to the content and the form of a patent application submitted to the Intellectual Property Office,a competent state institution for the protection of intellectual property. </p

Prescribing practices in Southeastern Europe – focus on benzodiazepine prescription at discharge from nine university psychiatric hospitals

There is much concern about the widespread long-term use of benzodiazepines. Our manuscript addressed its use in the region of Southeastern Europe, which seems extensive, but insufficiently explored. At nine university psychiatric hospitals (Croatia, Macedonia and Serbia), we retrospectively analyzed discharge summary documents to find the prevalence of discharge benzodiazepine prescriptions and the prescribed benzodiazepine doses. This study included 1047 adult subjects and showed that 81.9% of them had benzodiazepines prescribed in the discharge summary document, with high mean daily dose of around 5 mg lorazepam equivalents. Factors associated with the prescriptions were exclusively clinical factors (diagnosis of schizophrenia spectrum disorders, more lifetime hospitalizations, psychiatric comorbidity, co-prescription of antidepressant or mood stabilizer, shorter duration of the hospitalization), while socio-demographic factors were not found to influence benzodiazepine discharge prescriptions. Similarly, factors which influenced the prescription of higher daily benzodiazepine dose were more lifetime psychiatric hospitalizations and co-prescription of antidepressant or mood stabilizer, as well as the diagnosis of mental/behavioral disorders due to substance use and co-prescribed antipsychotic. Our data are emphasizing an urgent need for guidelines and improved education of both health care professionals and patients, in order to prevent long term benzodiazepine (mis)use and related side-effects