44 research outputs found
Mechanical and Microstructural Properties of HDPE Pipes Manufactured via Orbital Friction Stir Welding
In recent decades, extensive research has been performed on the friction stir welding of flat-shaped materials while pipe welding, particularly polymer pipes, still encounters challenging issues. This work presents a feasible route for joining high-density polyethylene (HDPE) pipes using an orbital friction stir welding (OFSW) set-up properly designed with a retractable pin tool. Fully consolidated joints were achieved using a portable heating-assisted OFSW system suited for on-site pipeline welding. The obtained joined pipes were characterized by a high-quality weld surface and a lack of defects arising from the tool-pin hole. The samples welded with the optimum parameters presented comparable properties with the base materials and even a slight increase in the tensile strength. The highest tensile and impact strengths were 14.4 MPa and 2.45 kJ/m2, respectively, which is 105% and 89% of those of the base material. XRD, FTIR, and SEM were also applied to assess the property changes in the HDPE pipes after the FSW process. The morphological analysis evidenced that the crystalline structure of the welded sample was similar to that of the base material, proving the effectiveness of the proposed technology
Knowledge Capital in the University of Babylon and the extent of its Investment in National Development
تهدف الدراسة إلى بيان مدى استثمار رأس المال المعرفي والمتمثل ببراءات الاختراع وأطاريح الدكتوراه ورسائل الماجستير في التنمية الوطنية وقد استخدم المنهج المسحي وأعدت استبانة لغرض جمع البيانات والمعلومات حول متغيرات الدراسة حيث كان مجتمع الدراسة مقسم على ثلاثة انواع هي (مجتمع أصحاب رسائل الماجستير، أطاريح الدكتوراه، براءات الاختراع) من أعضاء الهيأة التدريسية، وقد استخدمت العينة الطبقية التناسبية بالنسبة للمجتمع ال أول والثاني أما الثالث فقد اختير كله ليضاف على ما تمخض من حساب العينة والتي شملت العينة (15%) من المجتمع الرئيسي البالغ (913) تدريسي.
وكانت أهم النتائج التي خرجت بها الدراسة الآتي:
لم يرتق الاستثمار في جامعة بابل إلى واقع الطموح بل الدراسة تبدي تحفظها على المستثمر منه.
2. يوجد فرق معنوي ذو دلالة إحصائية ما بين التكرار الفعلي والمتوقع لمدى استثمار رأس المال المعرفي، في جامعة بابل بالتنمية الوطنية.
أما أهم التوصيات فكانت الآتي:
اعادة النظر في المنظومة الجامعية ككل، ووضع الاسس الكفيلة للنهوض بالبنى التحتية ولاسيما المتعلقة بإدارة المعرفة.
العمل على تفعيل استراتيجية مناسبة لجامعة بابل، وتبني مبدأ الجامعة المنتجة ضمن أهدافها، والتثقيف على ذلك ليكون موازيا لدأبها للحصول على شهادة الايزو العالمية.The study aims at determining the extent of investment of knowledge capital represented by patents, doctor degrees and master's thesis in national development. The survey method was used and a questionnaire was prepared for the purpose of collecting data and information about the study variables. The study population was divided into three types, The third class was chosen to add to the results of the sample calculation, which included the sample (15%) of the main population of (913) teaching.
The most important results of the study were:
The study shows its reservation to the investor.
There is a significant statistical difference between the actual and expected repetition of the amount of capital investment knowledge at the University of Babylon national development.
The most important recommendations were as follows:
Reviewing the university system as a whole and laying the foundations for the advancement of infrastructure, especially knowledge management.
Work on activating an appropriate strategy for the University of Babylon and adopt the principle of the university producing within its objectives and education in light of this to be parallel to the degree to obtain the ISO International Certificate
Global economic burden of unmet surgical need for appendicitis
Background: There is a substantial gap in provision of adequate surgical care in many low-and middle-income countries. This study aimed to identify the economic burden of unmet surgical need for the common condition of appendicitis. Methods: Data on the incidence of appendicitis from 170 countries and two different approaches were used to estimate numbers of patients who do not receive surgery: as a fixed proportion of the total unmet surgical need per country (approach 1); and based on country income status (approach 2). Indirect costs with current levels of access and local quality, and those if quality were at the standards of high-income countries, were estimated. A human capital approach was applied, focusing on the economic burden resulting from premature death and absenteeism. Results: Excess mortality was 4185 per 100 000 cases of appendicitis using approach 1 and 3448 per 100 000 using approach 2. The economic burden of continuing current levels of access and local quality was US 73 141 million using approach 2. The economic burden of not providing surgical care to the standards of high-income countries was 75 666 million using approach 2. The largest share of these costs resulted from premature death (97.7 per cent) and lack of access (97.0 per cent) in contrast to lack of quality. Conclusion: For a comparatively non-complex emergency condition such as appendicitis, increasing access to care should be prioritized. Although improving quality of care should not be neglected, increasing provision of care at current standards could reduce societal costs substantially
Pooled analysis of WHO Surgical Safety Checklist use and mortality after emergency laparotomy
Background The World Health Organization (WHO) Surgical Safety Checklist has fostered safe practice for 10 years, yet its place in emergency surgery has not been assessed on a global scale. The aim of this study was to evaluate reported checklist use in emergency settings and examine the relationship with perioperative mortality in patients who had emergency laparotomy. Methods In two multinational cohort studies, adults undergoing emergency laparotomy were compared with those having elective gastrointestinal surgery. Relationships between reported checklist use and mortality were determined using multivariable logistic regression and bootstrapped simulation. Results Of 12 296 patients included from 76 countries, 4843 underwent emergency laparotomy. After adjusting for patient and disease factors, checklist use before emergency laparotomy was more common in countries with a high Human Development Index (HDI) (2455 of 2741, 89.6 per cent) compared with that in countries with a middle (753 of 1242, 60.6 per cent; odds ratio (OR) 0.17, 95 per cent c.i. 0.14 to 0.21, P <0001) or low (363 of 860, 422 per cent; OR 008, 007 to 010, P <0.001) HDI. Checklist use was less common in elective surgery than for emergency laparotomy in high-HDI countries (risk difference -94 (95 per cent c.i. -11.9 to -6.9) per cent; P <0001), but the relationship was reversed in low-HDI countries (+121 (+7.0 to +173) per cent; P <0001). In multivariable models, checklist use was associated with a lower 30-day perioperative mortality (OR 0.60, 0.50 to 073; P <0.001). The greatest absolute benefit was seen for emergency surgery in low- and middle-HDI countries. Conclusion Checklist use in emergency laparotomy was associated with a significantly lower perioperative mortality rate. Checklist use in low-HDI countries was half that in high-HDI countries.Peer reviewe
Application and Characterization of Surfactants
The surfactants are among the materials that have a significant importance in everyday life of human. The rapid growth in science and technology has opened new horizons in a very wide range, in which the surfactants play a major and vital role. Hence, the increasing number of applications as well as arising environmental issues has made this relatively old topic still a hot research theme. In the first section of this book, some of the applications of surfactants in various fields such as biology and petroleum industry, as well as their environmental effects, are described. In Section 2 some experimental techniques used for characterization of the surfactants have been discussed
Phase diagrams of microemulsions containing reducing agents and metal salts as bases for the synthesis of metallic nanoparticles
We studied the phase diagrams of microemulsions with a view to using these systems for the synthesis of metallic Pt, Pb, and Bi nanoparticles as well as of intermetallic Pt/Pb and Pt/Bi nanoparticles. The microemulsions consisted of H2O/salt – n-decane – SDS – 1-butanol. The salt was either one metal precursor (H2PtCl6·6H2O, Pb(NO3)2, or Bi(NO3)3·5H2O), a mixture of two metal precursors (H2PtCl6·6H2O + Pb(NO3)2 or H2PtCl6·6H2O + Bi(NO3)3·5H2O), or the reducing agent (NaBH4). In addition, other salts needed to be added in order to solubilize the metal precursors, to stabilize the reducing agent, and to adjust the ionic strength. Combining the microemulsion (μe1) that contains the metal precursor(s) with the microemulsion (μe2) that contains the reducing agent leads to metallic nanoparticles. To study systematically how the shape and size of the synthesized metallic nanoparticles depend on the size and shape of the respective microemulsion droplets, first of all one has to find those conditions under which μe1 and μe2 have the same structure. For that purpose we determined the water emulsification failure boundary (wefb) of each microemulsion as it is at the wefb where the water droplets are known to be spherical. We found that the ionic strength (I) of the aqueous phase as well as the hard acid and hard base properties of the ions are the key tuning parameters for the location of the wefb.Other funderUniversity College Dublin. Centre for Synthesis and Chemical Biology (CSCB
The effect of optical dispersion on magneto-optical responses of single-cavity and dual-cavity magnetophotonic crystals at near infrared wavelengths
In this paper the magneto-optical responses of single-cavity and dual-cavity type
one-dimensional magnetophotonic crystals have been investigated considering the
constituent layers optical dispersion in near infrared region. The 4 × 4 transfer matrix method has been
utilized for calculations and analysis. The obtained results revealed that the resonance
transmittance mode is split into two separated modes for specific repetition numbers.
These modes are shifted toward the center of photonic band gap regarding the stronger
dispersion relations, in both single- and dual-cavity structures. But the amounts of the
shifts and their fine behavior are strongly dependent on the type of the structure. We
believe that the results of the present work would be practically helpful to precisely
design the miniaturized magneto-optical elements in micro- and nano-scale