Injection molding is a polymer processing technology used for manufacturing parts with elastic hinges. Elastic hinges are widely used in FMCG (Fast Moving Consumer Goods) packaging (e.g., bottle ...closures of shampoos, sauces) and in the electrical engineering industry. Elastic hinge is a thin film that connect two regions of the injection molded part, where significant shear rates are present, which can lead to the degradation of polymers and the decrease in mechanical properties. Selective induction heating is the method that improves the flow of the polymer melt through thin regions by the local increase in mold temperature. In this study, selective induction heating was used to improve mechanical properties of elastic hinges by the reduction of material degradation due to high shear rates. To verify the change of shear rates, selective induction heating simulation and injection molding simulations were performed. The linear relation between mold temperature and maximum shear rate in the cross-section was identified and the mechanical tests showed significant differences in hinge stiffness, tensile strength and elongation at break.
This paper presents a new method of aligning workpieces for machining by means of optical measurements followed by the results of verification tests of this method. The overview of modern assessment ...methods of irregularly shaped blanks are discussed in this study, with particular emphasis on cast iron castings, as well as on problems related to their positioning and fixing for machining. A flowchart of the proposed method and its verification results in industrial conditions are also presented. The essence of the method is based on the comparison of two spatial models: a designed workpiece model and the actual model of a casting produced with a coordinate measuring technique. A series of six iron castings were tested. The obtained results indicate that the errors caused by locating amounted to a maximum of 2 mm (average 0.5 mm) and were three times lower than actual machining allowances. This points to the correctness of the developed method and the great potential for its industrial application. Additionally, a method for improving locating accuracy by modifying the shape of the retaining pin is presented.
The use of selective induction heating of molding surfaces allows for better filling of molding cavities and has a positive effect on the properties of molded products. This is particularly important ...in the production of parts that include flexible hinges, which are thin plastic layers connecting two or more parts of the product. By using hinges, it is possible to expand the use of injection molding products and their capabilities. They are widely used in the production of parts for the electrical engineering industry and for packaging Fast Moving Consumer Goods (FMCG). The use of hinges also entails specific reductions in wall thickness. Increases in the shear rate can be expected, which can lead to the degradation of polymers and deterioration of mechanical properties of materials. This paper investigates injection molded flexible hinge parts manufactured with selective induction heating to improve their properties. To verify the efficiency of reduction of material degradation due to high shear rates, open/close tests of elastic hinges were performed. The linear relation between the number of cycles the hinges can withstand, mold temperature and injection time was identified, where mold temperature was the more significant factor.
castings. The possibility of reducing the total volume of machining allowances, reducing the wear of cutting tools, shortening machining time and eliminating idle machining passes was considered. The ...tests were carried out on two batches of castings supplied by two independent foundries. Casting geometry measurements were made using a structured light scanner. The analysis included machining with cemented carbide tools and tool ceramics at two machining centers: DMC200U and DMC270U. It has been shown that as a result of eliminating idle machining passes, it is possible to reduce machining time by 12% for the first and by 44% for the second casting supplier. The estimated annual savings for the production volume of 500 pcs of these castings can range from € 7388 to even € 23 346. The actual cost of cheaper casts was also calculated, taking into account the difference in machining cost resulting from larger machining allowances.
The hereby presented study puts forth the fundamentals of an innovative technology enabling rapid assessment of machine tool cast shape by elimination of manual marking out requirement and machining ...surplus minimization. The new technique is based on optical measuring system utilization for the design of virtual cast models and their comparative analysis with structural models. Two small scale machine tool body casts were selected for the investigation. The measurements were conducted in triplicate series for each cast labeled with reference markers, by means of Atos GOM II optical scanner. For further comparison, one of the casts was additionally scanned without labeling. Flatness parameters of selected cast surfaces were determined for geometric accuracy evaluation and the scanned cast shapes were compared with reference models. The comparison results were recorded as multicolored maps projected upon the experimental cast and reference model surfaces. Practical map interpretation was further elucidated and the surplus sizes on the machined surfaces were assessed accordingly. Comparative analyses of individual models were demonstrated for all measurement series of both casts, affording reproducibility evaluation of optical scanning system measurements. Economic viability of the proposed technology market implementation was unequivocally established, as it provides for considerable reduction in the cast machining scale as well as the quality control of 100%.
W pracy przedstawiono założenia nowej metody szybkiej oceny kształtu odlewów. Eliminuje ręczne trasowanie odlewów oraz minimalizuje naddatki obróbkowe. Podstawą metody jest zastosowanie optycznego systemu pomiarowego do tworzenia wirtualnych modeli odlewów oraz analizy porównawczej z modelami konstrukcyjnymi. Przyjęto do badań 2 rodzaje odlewów korpusowych o małych rozmiarach – komponentów obrabiarek skrawających. Pomiary prowadzono za pomocą skanera optycznego Atos GOM II. Wykonano serię 3 pomiarów każdego odlewu oklejonego znacznikami referencyjnymi. Dodatkowo, w celach porównawczych, jeden z odlewów zeskanowano bez znaczników. Dla oceny dokładności geometrycznej odlewów określono parametr płaskości dla wybranych ich powierzchni. Porównano kształt odlewów z modelami referencyjnymi. Wyniki badań przedstawiono w postaci map naniesionych na powierzchnie odlewu oraz modelu referencyjnego. Dokonano ich praktycznej interpretacji oraz oceny wielkości naddatków na powierzchniach obrabianych. Dla wykonanych serii pomiarów obu odlewów przedstawiono porównanie wyników poszczególnych modeli. Stanowiło to podstawę oceny powtarzalności pomiarów za pomocą optycznego systemu skanującego. Dokonano oceny efektów ekonomicznych opracowanej metody pomiarów.
Antibiotics represent an essential pillar in the treatment of respiratory infections (RI). Overuse of antibiotics in avoidable cases and inappropriate application in bacterial infections facilitate ...treatment resistance, threatening their effectiveness and causing a significant healthcare challenge. We therefore assessed the savings potential for antibiotics in ambulant care of selected RI (bronchitis and cough, pharyngitis, rhinosinusitis) in several European countries based on market research data for the year 2019. Number of antibiotic packages sold in pharmacies varied, with highest values in Serbia and France, and lowest in Sweden and Switzerland. Selected RI contributed nearly half of overall ambulant antibiotic prescriptions, with around one fifth given for bronchitis and cough; the vast majority was estimated to be of viral origin with potentially avoidable antibiotic use. Antibiotic consumption for selected RI in eight European countries (Austria, Belgium, the Czech Republic, France, Germany, Poland, Slovakia, and Switzerland) amounted to nearly 100 million, with an overall savings potential between 66.2 and 83.7 million packages. The highest estimated volume of avoidable antibiotics was in France (44.7 million, 0.80 per capita), and lowest in Switzerland (1.4 million, 0.18 per capita). Due to substantial savings potential, prudent use of antibiotics and adequate application of alternatives should be promoted in daily practice.
A
bstract
Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses proton-proton collision data corresponding to ...an integrated luminosity of 36.1 fb
−1
at a centre-of-mass energy of 13 TeV collected in 2015 and 2016 with the ATLAS detector at the Large Hadron Collider. Events are required to have at least one jet with a transverse momentum above 250 GeV and no leptons (
e
or
μ
). Several signal regions are considered with increasing requirements on the missing transverse momentum above 250 GeV. Good agreement is observed between the number of events in data and Standard Model predictions. The results are translated into exclusion limits in models with pair-produced weakly interacting dark-matter candidates, large extra spatial dimensions, and supersymmetric particles in several compressed scenarios.
A direct search for the standard model Higgs boson decaying to a pair of charm quarks is presented. Associated production of the Higgs and Z bosons, in the decay mode ZH→ℓ^{+}ℓ^{-}ccover ¯ is ...studied. A data set with an integrated luminosity of 36.1 fb^{-1} of pp collisions at sqrts=13TeV recorded by the ATLAS experiment at the LHC is used. The H→ccover ¯ signature is identified using charm-tagging algorithms. The observed (expected) upper limit on σ(pp→ZH)×B(H→ccover ¯) is 2.7 (3.9_{-1.1}^{+2.1}) pb at the 95% confidence level for a Higgs boson mass of 125 GeV, while the standard model value is 26 fb.
With the increase in energy of the Large Hadron Collider to a centre-of-mass energy of 13
TeV
for Run 2, events with dense environments, such as in the cores of high-energy jets, became a focus for ...new physics searches as well as measurements of the Standard Model. These environments are characterized by charged-particle separations of the order of the tracking detectors sensor granularity. Basic track quantities are compared between 3.2 fb
-
1
of data collected by the ATLAS experiment and simulation of proton–proton collisions producing high-transverse-momentum jets at a centre-of-mass energy of 13
TeV
. The impact of charged-particle separations and multiplicities on the track reconstruction performance is discussed. The track reconstruction efficiency in the cores of jets with transverse momenta between 200 and 1600
GeV
is quantified using a novel, data-driven, method. The method uses the energy loss,
d
E
/
d
x
, to identify pixel clusters originating from two charged particles. Of the charged particles creating these clusters, the measured fraction that fail to be reconstructed is
0.061
±
0.006
(stat.)
±
0.014
(syst.)
and
0.093
±
0.017
(stat.)
±
0.021
(syst.)
for jet transverse momenta of 200–400
GeV
and 1400–1600
GeV
, respectively.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A
bstract
A search is presented for particles that decay producing a large jet multiplicity and invisible particles. The event selection applies a veto on the presence of isolated electrons or muons ...and additional requirements on the number of b-tagged jets and the scalar sum of masses of large-radius jets. Having explored the full ATLAS 2015-2016 dataset of LHC proton-proton collisions at
s
=
13
TeV, which corresponds to 36.1 fb
−1
of integrated luminosity, no evidence is found for physics beyond the Standard Model. The results are interpreted in the context of simplified models inspired by R-parity-conserving and R-parity-violating supersymmetry, where gluinos are pair-produced. More generic models within the phenomenological minimal supersymmetric Standard Model are also considered.
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