Many tubular joints commonly found in offshore jacket structures are multi-planar. Investigating the effect of loaded out-of-plane braces on the values of the stress concentration factor (SCF) in offshore tubular joints has been the objective of numerous research works. However, due to the diversity of joint types and loading conditions, several quite important cases still exist that have not been studied thoroughly. Among them are internally ring-stiffened multi-planar XT-joints subjected to axial loading. In the present research, data extracted from the stress analysis of 81 finite element (FE) models, verified using experimental test results, was used to study the effects of geometrical parameters on the chord-side SCFs in multi-planar tubular XT-joints reinforced with internal ring stiffeners subjected to two types of axial loading. Parametric FE study was followed by a set of the nonlinear regression analyses to develop four new SCF parametric equations for the fatigue analysis and design of axially loaded multi-planar XT-joints reinforced with internal ring stiffeners.

سازمان ها نیاز دارند تا خود را در برابر چالش ها مصون نگاه دارند. لذا استفاده از فرایند برنامه ریزی راهبردی نقش کلیدی در موفقیت سازمان ها ایفا می کند، آگاهی از نقاط قوت و ضعف داخل سازمان و از طرفی فرصت ها و تهدیدهای موجود در محیط سازمان این توانایی را به سازمان می دهد تا موقعیت و جایگاه خود را ارزیابی کند. در این مقاله برای تدوین راهبرد از چارچوب جامع تدوین راهبرد استفاده شده است. که پس از تشکیل کمیته تدوین راهبرد، در مرحله شروع بیانیه ماموریت شرکت دکستروز ایران تعیین شد و سپس در مرحله ورودی ماتریس ارزیابی عوامل خارجی و ماتریس ارزیابی عوامل داخلی آورده شده است. با توجه به اطلاعات به دست آمده از مراحل قبل در مرحله مقایسه، از ماتریس سوات و ماتریس داخلی و خارجی استفاده شده است. در مرحله نهایی با استفاده از ماتریس برنامه ریزی راهبردی کمی، راهبردهای سطح کلان شرکت شناسایی و اولویت بندی شدند.

Considering the adverse effects of storage insect pests and their resistance to chemical insecticides, identifying safe, cost-effective, and durable methods to control and reduce storage pest-induced damage appears essential. Utilizing diatomaceous earth is one alternative to chemical pesticides for controlling stored-product insect pests.  This study evaluated the insecticidal activity of diatomaceous earth at a concentration of 0.2 mg/cm2 against two stored-products insect pests, Rhyzopertha dominica F. and Tribolium confusum Jacqulin Duval, on concrete, mosaic, and galvanized steel surfaces. To this end, the surfaces were treated with different diatomaceous earth formulations, including a commercial formulation, SilicoSec®, an Iranian formulation, Dryasil, Dryasil + 0.05% Mentha longifolia L. extract, and talcum powder + 0.05% M. longifolia extract. Mortality was measured 1, 3, 5, and 7 days after treatment. The experiment was conducted at 27 ± 1 °C, 60 ± 5% relative humidity, and dark conditions. The experiments were performed in nine replications (10 adults in each replication). The mortality percentage of R. dominica 7 days after treatment with Silicosec®, Dryasil alone, Dryasil + 0.05% M. longifolia extract, and talcum powder + 0.05% M. longifolia extract on galvanized steel were 43.33, 54.44, 33.33, and 25.55%, respectively. The results indicated that the mortality percentage of T. confusum on galvanized steel was 35.55, 45.55, 26.66, and 23.33%, respectively. The mortality of T. confusum was lower than that of R. dominica adults. Results indicated that the insecticidal effect of diatomaceous earth increased over time. Diatomaceous earth alone had a more significant insecticidal effect than combining them with M. longifolia extract. The highest percentage of mortality in all treatments was found on the galvanized steel, mosaic, followed by concrete surfaces, respectively. Therefore, Dryasil formulation can be used to control stored-products pests in grain silos, although its insecticidal efficacy varies based on surface type.