Influence of rotational speed on the electrical and mechanical properties of the friction stir spot welded aluminium alloy sheets

An efficient and productive joining technique to weld aluminium has become a priority challenge for promoting the use of aluminium in the electrical industry. One of the challenges is to obtain welds with superior mechanical properties with the consistent quality of weld surface as well as low electrical resistance. In this paper, the influence of rotational speed during the friction stir spot welding of AA 5754-H111 was studied to analyse the mechanical and electrical properties of the welds. The results from two rotational speeds (1000 rpm and 4500 rpm) are presented and compared to the base material. It was observed that the samples welded at 1000 rpm showed a higher average shear failure load (~ 1.1 kN) compared to the samples welded at 4500 rpm (~ 0.94 kN). The microhardness of the samples welded at 1000 rpm was higher than that of the base material, while the microhardness of samples welded at 4500 rpm was lower. It was also found that the friction welded sheets, regardless of the rotational speed used, showed increased electrical resistance compared to the base material, albeit this increase for the samples welded at 1000 rpm was about 42%, compared to samples welded at 4500 rpm where this increase was just 14%

Rehabilitation Protocols for Children with Dysfunctional Voiding

Dysfunctional voiding is a functional voiding disorder characterized by an intermittent uroflow rate due to involuntary intermittent contractions of the striated muscle of the external urethral sphincter or pelvic floor muscles (PFMs) during voiding in neurologically normal children. Symptoms include voiding difficulties as well as urgency, voiding frequency and, in some instances, urinary incontinence and/or nocturnal enuresis. Recurrent urinary tract infections, chronic constipation and/or fecal incontinence and vesicoureteral reflux (VUR) contribute to this condition. Urotherapy is the mainstay of the treatment. It starts with education and demystification and simple behavioral modifications. Specific measures include PFM exercises with various forms of biofeedback concentrating at the recognition of PFM function and their relaxation. However, the PFMs are part of the abdominal capsule and they act in coordination with lower abdominal muscles. These muscles need to be relaxed during voiding. Diaphragmatic breathing exercises were introduced to teach children abdominal muscle relaxation. Easy to learn exercises do not require any specific equipment and can be performed at all health care levels. Children from five years of age could benefit from these exercises. In children resistant to standard treatment, botulinum toxin type A application, intermittent catheterization and surgery in children with VUR are recommended

Dizajn, klasifikacija, perspektiva i moguća aplikacija dronova u poljoprivredu Srbije

The paper analyzes the possibility and the needs for the use of specific types of robots (mini unmanned aircraft with different designs and the designation of UAVs) and the possibility of using in agriculture (agrodrone). The year 2015 was proclaimed (Fortune Magazine, 2016) as the year of increasing and widespread use of UAVs in various areas of human activity, especially in agriculture and forestry (75% of use). This is important for large farm areas, where UAV has many useful functions and a very cost-effective commercial application. Today, the needs for UAVs have increased sharply with various opportunities for both civilian and military needs. There is also a significant interest in the development of new drones that can autonomously fly in different environments and locations and can perform various missions and tasks. Over the past decade, a wide range of applications for drones has gained the significance that led to the discovery of various types of unmanned UAVs of different sizes and weights. In this review, the classification of UAVs ranging based on a detailed overview of the development of the drone industry in recent years, this paper demonstrates the evolution of drones and differents application technologies. Of course, this development is very advanced and revolutionary, as well as the development of mobile and smart phones and the Internet, which will open the way for many users to participate in defining the future of UAV implementation. LIVONA Company, Belgrade, Serbia (and Institute of Agricultural Engineering, Faculty of Agriculture in Belgrade, in tehnical cooperation) has a study and plans on the implementation of the model micro drone EBee SQ Livona RTK in the future general plans for inspection of protection Soils of territory Minicipality of Stara Pazova (351 km2), and agricultural company Napredak , and exspecially plans for soils of agriculture of R. Serbia. VEKOM GeoCompany from Belgrade, (in cooperation with Institute of Agricultural Engineering, Faculty of Agriculture in Belgrade), has a study and plans on the implementation of the model of the drone Aibot KX6 model, in the future of application of agricultural soils of region Open pit Kolubara for area from app. 600 km2 and the other soils of Region). Institute of Agricultural Engineering, Faculty of Agriculture in Belgrade, in cooperation with Municipality of Ub, has a study and plans on the implementation of the model micro drone Hubsan H109S X4 PRO in the future plans general inspection of protection Soils and Waters of territory of Municipality Ub (456 km2).U radu su analizirane mogućnosti i potrebe upotrebe specifičnih vrsta robota (mini bespilotnih letelica sa različitim dizajnom, označane kao UAV) i način korištenja u poljoprivredi (agrodron). Časopis Fortune je 2015.godinu proglasio kao godinu sve većeg i široko rasprostranjene upotrbe UAV letelica, u različitim oblastima ljudske delatnosti, posebno u poljoprivredi i šumarstvu (75% upotrebe). Ovo je naročito važno za velike farme i oblasti pod šumama, gde UAV ima mnogo korisnih funkcija i veoma isplative komercijalne aplikacije. Danas, potrebe za UAV imaju nagli porast sa različitim mogućnostima kako za civilne tako i za vojne potrebe. Takođe postoji značajan interes za razvoj novih bespilotnih letelica koji mogu autonomno leteti u različitim okruženjima i lokacijama i obaviti različite misije i zadatke. Tokom protekle decenije XXI veka, širok spektar aplikacija za bespilotne letelice je dobio značaj koji je doveo do konstrukcija različitih tipova bespilotnih UAV, različitih veličina i težina i svakako namene. Naravno, tehnološki razvoj kod dron sistema je veoma tehničko-tehnološki napredan i revolucionaran, uz razvoj mobilnih i pametnih (android) telefona i interneta, brzo otvora puteve i mogućnosti za mnoge korisnike u definisanju nove budućnosti implementacije UAV u različitim oblastima primene . Kompanija Livona d.o.o., Beograd i Institut za poljoprivrednu tehniku, Poljoprivredni fakultet u Beogradu, u tehničkoj saradnji imaju planove o implementaciji modela mikro drona EBee SK Livona RTK u narednim generalnim planovima za inspekciju, zaštitu i korišćenje poljoprivrednih zemljišta Republike Srbije, i posebno teritorije Opštine Stara Pazova (351 km2), gde je posebno mesto poljoprivrednog preduzeća Napredak a.d. VekomGeo d.o.o, Beograd u saradnji sa Institutom za poljoprivrednu tehniku Poljoprivrednog fakulteta u Beogradu ima planove o budućoj upotrebi drona model Aibot X6, za nadzor na površinama od 600 km2 (i poljoprivredna zemljišta) otvorenog kopa R.B. Kolubara ili drugih objekata. Institut za poljoprivrednu tehniku, Poljoprivredni fakultet u Beogradu, ima planove o saradnji sa opštinom Ub, zbog upotrebe modela mikro drona Hubsan H109S Ks4 PRO u inspekciji oko zaštite i načina korišćenja zemljišta i voda na ovoj teritoriji (456 km2)

Importance of on-time decision making in energy sector based on perspectives: Case study new Stavalj project

Expression "Development conditions and perspectives" became important for numerous analyses in various industrial and social areas. Several strategic documents and studies in last two decades analysed projects with topics on perspectives of future development in Serbia. Various tools are used for development of such documents, based on recent scientific and numerical solutions, thus providing reliable assessment for strategic decision making. Almost all analyses tried to implement the theories and practical experiences through the prism of "sustainable development", which included establishment of most important sitstainability parameters. Analysis and ranking presented in this paper considered the potential of the Stavalj coal deposit, near city of Sjenica in Serbia, and feasibility of construction project of new mine and thermal power plant. Basis for analysis was a hybrid assessment model which takes into account principles of sustainable development. The model incorporates quantified SWOT analysis, which applies to active underground mines in Serbia. Special attention was given to the parameters describing potential for development

The influence of alkyl polyglucosides (and highly ethoxylated alcohol boosters) on the phase behavior of a water/toluene/technical alkyl polyethoxylate microemulsion system

The influence of additives (alkyl polyglucoside, Glucopon 600 CS UP and alcohol ethoxylate C18E100) on the behavior of the water/toluene/Lutensol ON 50 (technical oxoalcohol, i-C10E5) microemulsion system as a function of temperature and composition has been investigated. The phase behavior of the microemulsions was determined by vertical sections through the Gibbs phase prism (fish-like phase diagrams). Alkyl polyglucoside shifts the one phase region to lower temperatures compared with water/toluene/Lutensol ON 50 mixtures. This is contrary to the expectation, considering the extreme hydrophilic nature of the sugar headgroup. The addition of hydrophilic alcohol ethoxylate (C18E100) to the water/toluene/Lutensol ON 50 system increases the solubilization capacity of the surfactant, even if the co-surfactant is used in small quantities, and shifts the one-phase region to higher temperature by a few degrees Celsius. [Projekat Ministarstva nauke Republike Srbije, br. 172051

IMPLANTATION OF AN ICD AND DFT TESTING IN PATIENT WITH PERSISTENT LEFT SUPERIOR VENA CAVA

Aim. The implantable cardioverter-defibrillator [ICD] has been proven to reduce the risk of sudden cardiac death through the termination of ventricular fibrillation and life-threatening ventricular tachycardia. The simplest measure of defibrillation effectiveness is the DFT, defined as the lowest delivered shock strength required to defibrillate. Improved technology and use of ICDs for primary prevention have led some to question the need for either defibrillation testing or any assessment of defibrillation efficacy after implantation. Experts disagree about optimal testing because data are insufficient to define the trade-off between accuracy and risk of testing. However there are specific cases in which DFT is necessary.Material and methods. Authors describe the case of a patient with persistent left vena cava, a rare congenital anomaly, with no clinical importance which is usually accidentally revealed during the implantation of pacemaker or when placing a central vascular catheter. However, it represents a major problem and challenge for positioning of the standard pacemaker electrodes.Results. After a successful implantation via unconventional anatomic path authors carried out DFT testing to check that the device is functioning appropriately.Conclusion. Persistent left vena cava should not represent a contraindication for implantation of complex pacemaker systems such as ICD and DFT testing is advisable in this cases