Effects of Ultrasonic Nanocrystal Surface Modification (UNSM) on Residual Stress State and Fatigue Strength of AISI 304

The effects of a new mechanical surface treatment method, called ultrasonic nanocrystal surface modification (UNSM), on near-surface microstructures and residual stress states as well as on the fatigue behavior of an austenitic steel AISI 304 are investigated and discussed. The results are compared with consequences of other mechanical surface treatment methods such as deep rolling or shot peening.     

High performance thermoplastic composite from flat knitted multi-layer textile preform using hybrid yarn

Modern flat knitting machines using high performance yarns are able to knit fabrics including the reinforcement yarns arranged differently into knit structures. Due to their improved mechanical properties, composites made from multi-layer knit fabrics show great potential in lightweight applications. This paper reports on the development of flat knitted multi-layer textile preforms for high performance thermoplastic composites using hybrid yarns made of glass (GF) and polypropylene (PP) filaments. Such textile preforms with different reinforcements were used to consolidate into 2D thermoplastic composites. Moreover, the mechanical properties of these composites were studied. The mechanical properties of 2D composites were found to be greatly affected by different arrangements of reinforcement yarns. The integration of reinforcement yarns as biaxial inlays (warp and weft yarns) is found to be the best solution for knitting, whereas tuck stitch shaped and unidirectional arranged reinforcements offer also promising application possibilities.     

用于复合材料的针织间隔织物的开发

描述了在横机上开发两种间隔物的方法.织物有两睂外层,用U形或V形交连结构连接而成,主要应用领域为轻质复合材料.     

测量纱线长度和速度的非接触式传感器

介绍了一种新型测量纱线长度和速度的传感器,该传感器的功能已由实验证实.其原理是利用纱线上的静电荷进行非接触测量.所研制的传感器能用于测量各种原料纱线的长度和速度.在实际应用中,这种传感器可用于一些尚无经济实用解决方案的场合.     

Replica management for fault-tolerant systems

Replication has traditionally been used to assure fault tolerance. Active parallel replication is a new technique that, in addition to ensuring fault tolerance, dramatically reduces computation time and cost     

DREF摩擦纺与纱线特性的优化

摩擦纺对于产业用纺织品所需的新型纱线的开发提供了特殊的可能性.不同的纤维(包括短纤维)按照设计好的方式结合在纱线的横截面中,形成皮芯型多组分结构.描述了利用特殊的纺纱参数来设定纱线特性的技术和可能性及用摩擦纺纱线生产的主要产品.     

Neuroendocrine tumours of the digestive tract report of two cases and literature review

Neuroendocrine tumors (NET) of the digestive system are rare. They comprise only 1% of all the tumors of the gastrointestinal tract. The aim of this study is to report two cases of exceptional localization of non secretary neuroendocrine tumors. Their difficulty in diagnosis, treatment and controversy in chemotherapy merit their study in depth. These are two patients that were treated in the department of general surgery (Beau Séjour) in Charles Nicolle Hospital for non secretary (NET) of the pancreas and stomach. The first was presented as a painless epigastria mass with frequent diarrhea. The second was presented as a painful mass in the left hypochondriac area without any other symptoms. Biochemical evaluation confirmed their non secretary properties. Surgery remains the first line of treatment. It was possible for the gastric, but not for the pancreatic tumor. Both were very advanced and had metastasis. Histopathological evaluation and immunohistochemical study using the method of peroxydase antiperoxydase (PAP) complexes for some special monoclonal antibodies confirmed the diagnosis. Chemotherapy of both cases was mal tolerated and was discussed in details.     

Double-Diffusive Natural Convection in a Mixture-Filled Cavity with Walls' Opposite Temperatures and Concentrations

ABSTRACT

This paper deals with natural convection flows evolving inside an ended and differentially heated cavity, which is filled either with an air or an air–CO₂ mixture. The investigation was conducted through the laminar regime to analyze buoyancy ratio changes' effect on heat and mass transfers both in aiding and opposing flows. The thermal Rayleigh number was varied from 10³ to 10⁷. Streamlines, isotherms, iso-concentrations, and local and average Nusselt and Sherwood numbers are provided to demonstrate the convective flow induced. The governing equations are solved by finite volume method using SIMPLEC algorithm to handle the pressure–velocity coupling. The buoyancy ratio effect on dynamic, thermal, and mass fields is noteworthy, exhibiting both the competition between thermosolutal forces and fields' stratification. From the results, it turned out that, in general, when the buoyancy ratio is: (1) positive, thermosolutal buoyancy forces are cooperative, (2) nil, solutal buoyancy forces are weak and the flow is merely thermoconvective, (3) negative and greater than ?1, buoyancy effects are competing and thermal convection dominates, (4) ?1, buoyancy effects are canceled and heat and mass transfers are driven only by diffusion, and (5) less than ?1, buoyancy forces compete with a dominant solutal convection.