Ultrasonic welding of aluminum: a practical study in consistency, part marking and control modes

Patented in 1960, ultrasonic welding for metals, has received significant research and there have been advances in the technology. Because of these advances, the process has been developed into a practical production tool. Although the ultrasonic metal welding has many advantages including speed, efficiency, long tool life, there are several issues. For example, tool/part adhesion (sticking), part marking and the lack of the consistency and predictability of the weld strength are issues that industry currently encounters with ultrasonic metal welding. To resolve these issues of the ultrasonic metal welding process, various experiments have been conducted on aluminum 5754 alloy samples. These experiments included replacing a constant amplitude with amplitude profiling and placing buffer sheets of copper and zinc between the tool (horn) and the top part prior to ultrasonic welding. In addition, experiments were conducted to compare the consistency of weld strength for the three control modes: energy, height (post height), and time. Their results were analyzed and compared in terms of weld strength, weld consistency and weld quality.;It was seen that amplitude profiling produced an increase in weld strength, however the part marking and the tool/part adhesion were not reduced. By matching the amplitude to the various weld phases, the weld cycle was optimized to produce relatively strong welds and weld cycle time was reduced. For example, by initiating the weld cycle with a relatively high amplitude, the asperity peaks are sheared, heating and softening of the faying surfaces are completed quickly and efficiently. Then by reducing the amplitude at the end of the weld cycle, shearing of the weld is reduced and weld damage is minimized resulting in relatively strong welds.;Very simple models based on frictional heating were able to predict power dissipation reasonably well. When these models were coupled with a one dimensional heat flow solution, the initial bondline temperatures were accurately predicted. However, the predicted temperatures diverged from the measured temperatures as a function of cycle time. It is believed that this deviation was due to the over simplified assumptions used to model the process. For example, the assumption that the process could be modeled with one dimensional heat flow in a semi-infinite body was seen to be false shortly after the weld process was initiated.;The study involving the placement of buffer sheets (copper or zinc) between the tool (horn) and the top part prior to the ultrasonic welding process reduced the tool/part adherence and the part marking. However, it was seen the use of buffer sheets slightly lowered the weld strength and this was especially seen for the thicker (3-mm) parts and copper buffer sheets. It was also seen that zinc buffer sheets did not lower weld strength as much as the use of copper buffer sheets.;Also, it was concluded that the weld strength variance for those welds made with the time mode was smaller than that for the welds made in the height and energy mode

Quality of Life Assessment Based on Spatial and Temporal Analysis of the Vegetation Area Derived from Satellite Images

The quality of life in urban areas is a function of many parameters among which, one highly important is the number and quality of green areas for people and wildlife to thrive. The quality of life is also a political concept often used to describe citizen satisfaction within different residential locations. Only in the last decades green areas have suffered a progressive decrease in quality, pointing out the ecological urban risk with a negative impact on the standard of living and population health status. This paper presents the evolution of green areas in the cities of South-Eastern Romania within the last 20 years and sets forth the current state of quality of life from the perspective of vegetation reference. By using state-of-the-art processing tools applied on high-resolution satellite images, we have derived knowledge about the spatial and temporal expansion of urbanized regions. Our semi-automatic technologies for analysis of remote sensing data such as Landsat 7 ETM+, correlated with statistical information inferred from urban charts, demonstrate a negative trend in the distribution of green areas within the analyzed cities, with long-term implications on multiple areas in our lives

EU security challenges and their economic implications

Considering the volatile political, economic and security present environment, the European Union is currently facing more challenges than ever before in its existence. In addition to the challenges deriving directly from its status as a political-economical union of states, the EU is facing increasingly serious security challenges. Some of these challenges are not new, such as those identified in the seminal document “A Secure Europe in a Better World’ adopted by EU in 2010 (which singles out five key threats: terrorism, proliferation of weapons of mass destruction, regional conflicts, state failure, organized crime). Other security challenges have emerged more recently, such as illegal migration or the worsening of the relations with Russia. Although the nature of these challenges is related to security and defense, many of them have economic implications and it is the purpose of this paper to analyze the complex interactions between the security and the economic challenges faced by the EU, and also by the individual member countries.peer-reviewe

Infekcija bakterijom Clostridium diffi cile u djece: značajke i liječenje – istraživanje u jednom centru u Rumunjskoj

The incidence of Clostridium diffi cile infection (CDI) in children is progressively increasing. The study evaluated the characteristics and antibacterial treatment of CDI at a Romanian pediatric gastroenterology department. We performed a retrospective study to analyze cases diagnosed with CDI, identifi ed through immunoassays for Clostridium diffi cile toxins in stools, between January 1, 2005 and December 31, 2015. Eighty-nine episodes of CDI were diagnosed in 73 patients. We noticed an increasing incidence reaching maximum in 2014 with 6.9 cases/1000 patients. Almost 40% of patients had community-acquired CDI. The most frequently associated comorbidities were infl ammatory bowel disease and cow’s milk allergy. There was a small percentage of recurrent episodes (24.2%). Metronidazole was administered as fi rst-line treatment in 49.2% of mild/moderate cases and proved eff ective in 79.4% of these. More than 70% of all patients in which metronidazole was not effi cient had comorbidities, compared to 22.2% of patients where metronidazole was effi cacious. The alternative was vancomycin which cured the disease in all cases. In severe forms, a combination of intravenous metronidazole and oral vancomycin was the effi cient solution. Oral vancomycin was the effi cacious treatment for the fi rst recurrence. We report an increasing incidence of CDI in Romanian children. The failure rate for metronidazole treatment was low, thus metronidazole may be safely recommended for the fi rst episode of mild/moderate CDI. Vancomycin proved eff ective in all cases, regardless of the fi rst episode or recurrence, and may be used effi ciently as fi rst-line treatment.Incidencija infekcije bakterijom Clostridium diffi cile (CDI) u djece u progresivnom je porastu. U ovom istraživanju procijenjene su značajke i antibakterijska terapija CDI na jednom odjelu pedijatrijske gastroenterologije u Rumunjskoj. Provedeno je retrospektivno istraživanje u kojem su analizirani slučajevi CDI utvrđeni na osnovi imunoloških testova na toksine Clostridium diffi cile u stolici od 1. siječnja 2005. do 31. prosinca 2015. godine. U 73 bolesnika dijagnosticirano je 89 epizoda CDI. Zabilježena je rastuća incidencija CDI s najvišom stopom 2014. godine sa 6,9 slučajeva na 1000 bolesnika. CDI stečena u zajednici utvrđena je u gotovo 40% bolesnika. Najčešće pridružene istodobne bolesti bile su upalna crijevna bolest i alergija na kravlje mlijeko. Postotak ponovljenih epizoda bio je nizak (24,2%). Metronidazol kao terapija prvog izbora davao se u 49,2% blažih/umjerenih slučajeva i pokazao se učinkovitim u 79,4% njih. Istodobno prisutne bolesti zabilježene su u više od 70% bolesnika u kojih metronidazol nije bio učinkovit u usporedbi s 22,2% bolesnika kod kojih je metronidazol bio učinkovit. Alternativna terapija bio je vankomicin koji je izliječio bolest u svim slučajevima. U teškim oblicima bolesti kombinacija intravenskog metronidazola i peroralnog vankomicina pokazala se učinkovitim rješenjem. Peroralni vankomicin bio je učinkovit u liječenju prve ponovljene epizode bolesti. Ukazuje se na rastuću incidenciju CDI kod rumunjske djece. Stopa neupješnog liječenja metronidazolom bila je niska pa se ovaj lijek može sa sigurnošću preporučiti za liječenje prve epizode blaže/umjerene CDI. Vankomicin se pokazao učinkovitim u svim slučajevima bez obzira na to radi li se o prvoj ili ponovljenoj epizodi bolesti i može se učinkovito primijeniti kao terapija prvog izbora

Approaches Regarding Business Logic Modeling in Service Oriented Architecture

As part of the Service Oriented Computing (SOC), Service Oriented Architecture (SOA) is a technology that has been developing for almost a decade and during this time there have been published many studies, papers and surveys that are referring to the advantages of projects using it. In this article we discuss some ways of using SOA in the business environment, as a result of the need to reengineer the internal business processes with the scope of moving forward towards providing and using standardized services and achieving enterprise interoperability.Business Rules, Business Processes, SOA, BPM, BRM, Semantic Web, Semantic Interoperability

Study regarding the impact of waste landfills on surface waters

The waste management problem is an issue of global interest associated with high costs due to the degree of hazard that they have on the environmental factors and on human health. The present paper aims to evaluate the impact generated by non-ecological waste landfills on surface waters, compared with the impact of ecological hazardous waste landfills on surface waters. The study was possible due to the location of the two landfills, situated near the same watercourse. The water samples taken and analyzed show the extent of the impact of non-ecological waste landfills, compared with the impact generated by the ecological hazardous waste landfills on surface waters, located downstream from the household waste landfill. Therefore, the objective of this study is to emphases the impact brought upon the surface watercourses by waste landfills in the municipality of Cluj-Napoca

PLANTS FROM ILFOV COUNTY PRESENT IN "ALEXANDRU BELDIE" HERBARIUM

The present article describes the plants collected from Ilfov County area and presented in “Alexandru Beldie” Herbarium from “Marin Drăcea” National Institute for Research and Development in Forestry. The article presents the studied material, the number of vouchers with species harvested from this area as well as some characteristics of the plant collections. The most important species collected from Ilfov County are also mentioned, with an analysis of their characteristics: the collection’s creation period and the plant’s harvesting periods. The found genera were systematized, with an emphasis on the most representative ones. Furthermore, the specialists that had an important contribution for the representation of county area within the herbarium are also mentioned and honored

Researches on the Pollution of Underground Waters in a Certain Part of Galati District

The paper underlines the importance of monitoring the quality of the underground waters and presents the experimental results as regards the pollution of underground waters in a certain part of Galati district. The final target of underground waters quality monitoring is to design quality and quantitative prediction models and provide monitoring and optimization programs for environment investigations. Much interest is currently attached to the rehabilitation of, aquifer

HPTLC assay of nicotine and cotinine in biological samples

This study presents the development of a simple high-performance thin layer chromatography (HPTLC) method for the determination of nicotine and its metabolite cotinine in human plasma and urine. The following mobile phases: methanol: ammonia (100:1.5, v:v), chloroform: acetone: ammonia (48.75: 48.75: 2.5, v:v:v), methanol: chloroform: ammonia (48.75: 48.75: 0.5, v:v:v) and glass plates precoated with silicagel 60 F254 (20x20) as a stationary phase were used. Densitometric scanning was performed at 263 nm. Two different extraction procedures have been applied: liquid-liquid extraction using dichloromethane at alkaline pH and solid-phase extraction using C18 cartridges. Preliminary tests in order to establish the system of solvents for development, as well as the range of linearity, were conducted. The best separation of nicotine and cotinine was obtained by using methanol: chloroform: ammonia (48.75: 48.75: 0.5, v:v:v) as the mobile phase. The liquid-liquid extraction technique led to better results than solid phase extraction. The regression curves were linear (with a corresponding correlation coefficient higher than 0.99) in the quantities range of 200 ng–1000 ng/spot for both nicotine and cotinine. The UV spectra confirm the identification of nicotine and cotinine both in the standards and in the extracts after liquid-liquid extraction. The proposed method can be applied for the simultaneous evaluation of nicotine and cotinine in biological samples at toxic/lethal levels. Thus, the method may be applicable in lethal nicotine intoxication cases in forensic toxicological analysis