Contact Applications Research Articles

Chemical Composition, Antioxidant, Antimicrobial, Antibiofilm and Anti-Insect Activities of Jasminum grandiflorum Essential Oil

The essential oil of Jasminum grandiflorum has very good biological activity. The present study aimed to analyze the chemical composition and biological activity of J. grandiflorum. The main constituents of J. grandiflorum essential oil were benzyl acetate (37%), benzyl benzoate (34.7%) and linalool (9.6%). The antioxidant activity was 58.47%, which corresponds to 220.93 TEAC. The antimicrobial activity was weak to moderate, with inhibition zones ranging from 2.33 to 5.33 mm. The lowest MIC value was against Candida glabrata. The antimicrobial activity of the vapor phase of the essential oil was significantly stronger than that of the contact application. Biofilm analysis using a MALDI-TOF MS Biotyper showed changes in the protein profile of Pseudomonas fluorescens that confirmed the inhibitory effect of J. grandiflorum. The insecticidal potential of the essential oil against Oxycarenus lavatera and Brassicogethes aeneus was also demonstrated. Due to the properties of J. grandiflorum essential oil, it could find application as a biofilm control agent for the shelf-life extension and storage of fruits and vegetables and as a possible insecticidal agent.

Effect of surfactant concentration in sodium ascorbate on contact angle and tensile bond strength after bleaching

Free radical residue due to intracoronal bleaching using 35% hydrogen peroxide (HP) can be removed with 35% sodium ascorbate (SA) combined with surfactants. This study aimed to determine the effect of surfactant concentration in SA 35% on the contact angle and tensile bond strength of composite resin after intracoronal bleaching with 35% HP. The contact angle was observed in 3 groups of 35% SA: group 1 (without surfactant); group 2 (with 0.2% surfactant); group 3 (with 0.4% surfactant). Each sample was dropped on a glass slide perpendicularly, then the image was taken at the fifth minute and contact angle value was obtained using ImageJ software. Tensile bond strength in this study used 21 premolars, which were cut and fixed with acrylic resin. 35% HP (0.01 ml) was applied to tooth surface for 5 days, then washed and dried. Specimens were divided into 3 groups, each of which was applied with 0.01 ml 35% SA without surfactant (group 1), 35% SA with 0.2% surfactant (group 2), and 35% SA with 0.4% surfactant (group 3) for 5 minutes, before they were washed and dried. All specimens were filled with composite resin, and incubated in artificial saliva for 7 days inside an incubator (37oC) before the specimens were tested with Universal Testing Machine (speed 0.5 mm/minute). ANOVA analysis showed the effect of surfactant concentration in 35% SA on the contact angle and tensile bond strength after intracoronal bleaching with 35% HP. In conclusion, 35% SA with 0.4% surfactant had a smaller contact angle and application of 35% SA with 0.4% surfactant after intracoronal bleaching with 35% HP had a greater tensile bond strength.

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User Friendly Android-based Contact Application: Case of Accessible Contact in Educational Organization

Abstract: In a digital era, people prefer to use smart gadgets and it is growing to be instrumental in daily lives. The features of the smartphone are also evolving, leading to effectiveness for end users. With such an aim, an android-based contact application was developed that would benefit an organization. As an interim measure, this application is based on Jigme Namgyel Engineering College under the Royal University of Bhutan. Currently, this organization do not have a 'contact application' that can be used as a digital phonebook. Therefore, the entire faculty, staff, and students have to search for contact details through person-to-person communication leading to several inconveniences. This android base application called JNEC Contact made contact detail of the college’s staff available and accessible to staff and students without an internet connection. This application is implemented specifically for JNEC to ease the difficulties of acquiring contact information of faculty and staff. The application titled JNEC Contact has other features such as text messages and mail-to-direct correspondence. It is known to be more comfortable, efficient, and user-friendly to find a contact, unlike the phonebook. The current version of the application has limited compatibility with the android version only, but it can be developed for IOS phones in the future.

Characterization and Tribological Behavior of Electroless-Deposited Ni-P-PTFE Films on NBR Substrates for Dynamic Contact Applications

The use of rubber in dynamic contacts often results in severe degradation and wear of the rubber surface, which is why dynamic rubber seal contacts are usually oil lubricated to ensure their functionality. However, the increasing demand for more convenient and environmentally friendly sealing solutions has prompted the development of dry low-friction rubber coatings. In this work, and for the first time, Ni-P and polytetrafluoroethylene (PTFE) particles were co-deposited by electroless plating on Nitrile Butadiene Rubber (NBR), as a low-cost solution to improve the NBR tribological behavior. A cationic surfactant, cetyltrimethylammonium bromide (CTAB), was added to the plating bath to ensure a homogeneous and efficient incorporation of PTFE into the Ni-P. The optimized PTFE incorporation reached 6.8%, and the composite coating adhesion to NBR was 20% higher than that of nickel-phosphorous (Ni-P) films. The tribological properties of the coatings evaluated by pin-on-disk tests showed a marginal decrease in the coefficient of friction (CoF) (10%, 1 N load), compared to that of Ni-P. However, the tested PTFE-based coatings displayed significantly smoother surfaces with less debris and cracks, clearly demonstrating the benefits of the PTFE in terms of wear resistance for loads up to 5 N.

Phase-transforming Ag-NiTi 3-D interpenetrating-phase composite with high recoverable strain, strength and electrical conductivity

It is of particular interest to achieve high elastic recoverable strain in the electrical contact materials while maintaining good electrical conductivity and decent tensile strength. It remains a challenge, especially for bulk-sized metallic materials, as the electrical conductivity and elastic strain limit (or tensile strength) are often mutually exclusive. Here, we present a material design strategy for overcoming this conflict by developing a Ag-NiTi composite with an interpenetrating-phase architecture via infiltrating Ag melt into the partially sintered porous NiTi scaffold. The composite exhibits a good combination of properties with high electrical conductivity comparable to metals, large elastic recoverable strain superior to most of bulk-sized conductive metals as well as higher tensile strength than most of alloys/composites based on silver and other noble metals. This new finding demonstrates that the interpenetrating-phase architecture design is promising for developing new materials for electrical contact application.

Mechanical recyclability of biodegradable polymers used for food packaging: case study of polyhydroxybutyrate-co-valerate (PHBV) plastic

For the purpose of mechanical recycling for food contact applications, decontamination of polyhydroxybutyrate-co-valerate (PHBV) plastic was performed under different temperatures and time conditions. As expected, increasing the decontamination temperature and duration increased the decontamination efficiency, but also the degradation of the polymer. The combination 160 °C/6 h was selected as the optimal conditions that maximize contaminants removal while minimizing polymer degradation. Then the safety of the recycled PHBV under these conditions was assessed, in accordance with EFSA regulation based on bottle-to-bottle PET recycling. Decontamination of low molecular weight molecules such as toluene, chlorobenzene, and methyl salicylate was nearly complete with residual concentrations below the modeled concentrations allowed in the polymer when the adult scenario is considered. However, the higher molecular weight and lower volatility molecules exhibited acceptable decontamination efficiencies, but their residual concentrations in the polymer exceeded the maximum concentrations of no concern. The presence of these molecules allows the use of nearly 21% recycled PHBV in the new materials to meet safety criteria. It is important to keep in mind that this work, never done before, is a preliminary work on mechanical recycling of PHBV, mainly based on extrapolation of PET conditions and regulations. Much more research needs to be done to improve the decontamination process, the barrier properties of PHBV or to think about a short recycling line for PHBV.

Endorectal contact radiation boosting: Making the case for dose AND volume reporting

IntroductionThe various rectal endoluminal radiation techniques all have steep, but different, dose gradients. In rectal contact brachytherapy (CXB) doses are typically prescribed and reported to the applicator surface and not to the gross tumor volume (GTV), clinical target volume (CTV) or organs at risk (OAR), which is crucial to understand tumor response and toxicity rates. To quantify the above-described problem, we performed a dose modeling study using a fixed prescription dose at the surface of the applicator and varied tumor response scenarios. MethodsEndorectal ultrasound-based 3D-volume-models of rectal tumors and the rectal wall were used to simulate the delivered dose to GTV, CTV and the rectal wall layers, assuming treatment with Maastro HDR contact applicator for rectal cancer with a fixed prescription dose to the applicator surface (equivalent to 3 × 30 Gy CXB) and various response scenarios. ResultsAn identical prescribed dose to the surface of the applicator resulted in a broad range of doses delivered to the GTV, CTV and the uninvolved intestinal wall. For example, the equieffective dose in 2 Gy per fraction (EQD2) D90% of the GTV varied between 63 and 231 Gy, whereas the EQD2 D2cc of the rectal wall varied between 97 and 165 Gy. ConclusionDoses prescribed at the surface are not representative of the dose received by the tumor and the bowel wall. This stresses the relevance of dose reporting and prescription to GTV and CTV volumes and OAR in order to gain insight between delivered dose, local control and toxicity and to optimize treatment protocols.

Insecticidal Activity of Berberis Royleana: Various Extracts against Callosobruchus Maculatus

The residents of remote areas in developing countries mostly rely on traditional plants to curedifferent ailments. Berberis royleana is a rare species among the genus Berberis whichcommonly comprises 500 species distributed in Nepal, Afghanistan, Siberia, and other parts ofthe world. Berberis are used to make herbal medication to fight against infections, oculartrachoma, AIDS, and diarrhea. The current study was carried out to explore the in vitroinsecticidal activity of B. royleana in various extracts by direct contact application processagainst the insect Callosobruchus maculatus. The maximum mortality rate of 60% was recordedby water fraction, whereas methanolic fraction had 50% mortality, n-Hexane had 40% mortality,while ethyl acetate and chloroform both had 30% mortality at 72 hours. Thus, this studyindicated that from the medicinal point of view this specie is very significant, with a greatpotential for insecticidal activities against C. maculatus. It is further suggested that B. royleanacould be used as a good insecticidal agent against dengue and malarial vectors. In addition, theside effects like toxicity could be addressed to avoid any mishaps.

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Evaluating the food safety and risk assessment evidence-base of polyethylene terephthalate oligomers: Protocol for a systematic evidence map.

Polyethylene terephthalate (PET) oligomers are ubiquitous in PET used in food contact applications. Consumer exposure by migration of PET oligomers into food and beverages is documented. However, no specific risk assessment framework or guidance for the safety evaluating of PET oligomers exist to date. The aim of this systematic evidence map (SEM) is to identify and organize existing knowledge clusters and associated gaps in hazard and exposure information of PET oligomers. Research needs will be identified as an input for chemical risk assessment, and to support future toxicity testing strategies of PET oligomers and regulatory decision-making. Multiple bibliographic databases (incl. Embase, Medline, Scopus, and Web of Science Core Collection), chemistry databases (SciFinder-n, Reaxys), and gray literature sources will be searched, and the search results will be supplemented by backward and forward citation tracking on eligible records. The search will be based on a single-concept PET oligomer-focused strategy to ensure sensitive and unbiased coverage of all evidence related to hazard and exposure in a data-poor environment. A scoping exercise conducted during planning identified 34 relevant PET oligomers. Eligible work of any study type must include primary research data on at least one relevant PET oligomer with regard to exposure, health, or toxicological outcomes. For indexed scientific literature, title and abstract screening will be performed by one reviewer. Selected studies will be screened in full-text by two independent reviewers. Gray literature will be screened by two independent reviewers for inclusion and exclusion. Risk of bias analysis will not be conducted as part of this SEM. Will be performed by one reviewer and peer-checked by a second reviewer for indexed scientific literature or by two independent reviewers for gray literature. The extracted and coded information will be synthesized in different formats, including narrative synthesis, tables, and heat maps. Zenodo: https://doi.org/10.5281/zenodo.6224302.

Martensitic Stainless Steels for Food Contact Applications

For industrial mechanical food processing steps, like cutting, slicing, grating, passing or similar applications, tools of martensitic stainless steels are used preferably because of their high hardness and corrosion resistance. The latter is decisive to avoid contamination of foodstuff by elements transferred from the steel alloy into the processed food. In this contribution various martensitic stainless steels in different heat treatment conditions were investigated regarding their metal release behavior in food simulants. Therefore, migrations tests were carried out according to the guideline of the Council of Europe. During the examination, the specific migration of elements was determined and compared to defined release limits, which take into account the different toxicity for the human body. The results allow an assessment of the suitability of the tested grades and heat treatment conditions as contact material for different types of food.

Untangling leaf expansion triggers: A new experimental study with Epipremnum aureum (Araceae)

Allomorphic aroid vines exhibit a distinct morphology compared to the typical “sun and shade” leaf pattern. Their leaves exposed to high light irradiance at canopies are up to 30 times larger in area compared to leaves in the forest understory. Growth axis direction, contact with the host, and canopy light are morphogenesis-inducing factors for these aroids. While the first two factors are directly related to growth, the light obtained at canopies is associated with foraging and reproduction. In previous studies, the stimulus of light or the simultaneous application of contact and growth axis direction was not able to induce intense changes in leaf, petiole, and stem dimensions, as seen in nature. In this study, we tested the simultaneous interaction of light intensity, growth axis direction, and contact as inducing factors of morphological shoot development in the allomorphic aroid vine, Epipremnum aureum. An experiment with 60 cuttings was established, which included three growth conditions (horizontal, hanging, and climbing) and two light conditions (low light and high light). After 10 months, the leaf, petiole, and internode dimensions and dry mass allocation were compared. In both the horizontal and hanging treatments, the presence of high light doubled the individual leaf area to approximately 60 cm2. However, when high light was combined with vertical growth and contact stimuli in the climbing treatment, this increase was 20-fold, producing leaves up to 1,000 cm². Dry mass allocation followed the same pattern. This result shows that the enormous leaf area expansion of E. aureum is a synergistic effect of the simultaneous application of light, growth axis direction, and contact. The increase in light interception by wider leaves is an advantage to the maintenance of allomorphic aroid vines in a variable light environment such as in canopies.

Investigation of the Microstructure and Properties of Aluminum–Copper Compounds Fabricated by the High-Pressure Die Casting Process

The material combination of aluminum and copper is increasingly coming into focus, especially for electrical contact applications. Investigations of different casting processes show that a significant influence for the formation of a material bond is the thermal impact. For high-pressure die casting (HPDC) processes, the impact is quite low, e.g., due to short cycle times. Despite the high efficiency of this technology, currently there are hardly any investigations in this respect. So, the technology was used in this study to produce aluminum–copper compounds and analyze interfacial layers by means of SEM images and EDX measurements. Furthermore, the mechanical and electrical properties of the compounds were determined by means of tensile shear tests and measurements of the electrical conductivity. By modifying specimen geometry, the thermal impact could be increased and, thus, enhanced compound properties were achieved. Overall, compounds of sufficiently high mechanical strength, as well as electrical conductivity, could be produced by HPDC processes, demonstrating the high technical and economic potential of this casting technique.

Online compliance error compensation system for industrial manipulators in contact applications

Industrial manipulators are rarely used in high-force processes even though they provide flexibility, adaptability, relatively low cost, and a large workspace. This limited utilization is mainly due to their inherent low stiffness, which results in significant deformation. Hence, it is necessary to improve their accuracy in order to achieve high-precision requirements while performing tasks under load. This paper focuses on the development and implementation of an online compliance error compensation system for industrial manipulators. The proposed algorithm computes the compensation based on an elasto-geometric robot model and process forces measured with a force sensor mounted between the robot mechanical interface and the end effector. The performance of the compensation system is evaluated experimentally in two high payload robots from different manufacturers in which the compensation was carried out to reduce the mean deformation of circular trajectories under load. • Compensation is computed using an elasto-geometric model and measured process forces. • Deformation is compensated by online adaptation of the position reference signal. • Experiments considered several sections of the workspace, payloads, and TCP speeds. • Performance criteria evaluated the distance between loaded and unloaded trajectories.

Innovative eco-friendly active packaging strategy aimed for ethylene removal

Within the scope of sustainability, this work tackles both food waste and food safety by studying the ethylene scavenging potencial of α-cyclodextrin nanosponges produced by solvent-free synthesis and the food safety evaluation of the compostable packaging for food contact applications where the nanosponges will be incorporated.

Migration of Styrene in Yogurt and Dairy Products Packaged in Polystyrene: Results from Market Samples.

The European Food Safety Authority is re-evaluating styrene for assessing the safety of food contact materials (FCM) such as polystyrene (PS) and started a systematic review of the data on migration levels in food. A restriction for styrene is expected in the near future. The main food contact application of PS is dairy packaging, mainly at refrigerated storage. In this study, seventeen dairy products packed in PS taken from the Italian and German markets were investigated. Styrene concentrations in the refrigerated dairy products (yogurt, cream) ranged from 5 to 30 µg/kg at the best before date, while in single serving portions of coffee creamer, which were stored at room temperature until the best before date of approx. 190 days, 401 µg/kg were measured. Among several parameters, the ratio between the surface contact area of the package and the quantity of the food packed, the time/temperature conditions of production/filling and storage of the products were identified as the main factors influencing styrene migration into food under realistic conditions. Yogurts fermented in the pots for approximately 8 h at 40–50 °C showed higher styrene levels than those fermented in an incubator and filled at 20 °C. The fat content might influence the styrene level but the effect, if any, was too small in relation to the variability of other parameters. Levels of styrene migrating into 50% ethanol food simulant under standardized condition (10 days/40 °C) were found to be much higher than levels in refrigerated foods. This raises the question as to whether compliance testing for PS plastics should be adapted taking into consideration the correlation between migration testing by laboratory simulations and migration into real food.

Innovative Codeposition of a Ag-Al2O3 Layer: An Attractive Combination of High Durability and Lack of Cytotoxicity for Public Space Applications.

Today, the use of silver in surfaces for public environments is very frequent, as it ensures high antimicrobial activities, avoiding the continuous disinfection of the surfaces themselves. Similarly, thanks to its interesting combination of technological properties, anodized aluminum is widely employed in the production of components for applications in public spaces. Therefore, this work describes a simple method of the codeposition of silver and anodized aluminum to combine the remarkable properties of Al2O3 layers with the antibacterial performances of silver. The effect of silver in modifying the durability features of the anodized aluminum layer was evaluated by means of various accelerated degradation techniques, such as the exposure in a climatic chamber to UV-B radiation or an aggressive atmosphere simulated by the Kesternich test. These analyses showed the good compatibility between Ag and the alumina matrix, whose durability performances were not particularly influenced by silver. Furthermore, the composite layers did not express relevant cytotoxicity activity, as evidenced by Trypan blue flow cytometry analysis and microscopy observations, ensuring the possible use of this material in applications in close contact with humans. This same conclusion was reached by observing an almost negligible ionic release of Ag by the composite layers, even following severe degradation of the alumina matrix due to exposure to a particular acid solution. In conclusion, this work presents an innovative material that can be used in public spaces, thanks to its interesting combination of high durability and low cytotoxicity.

B/S-Based Construction of a Big Data Logistics Platform.

Due to the overwhelming characteristic of the Internet of Things, devices belonging to these networks are utilized in almost every domain of real life in order to improve the lifestyle of humans. However, these networks result in a huge amount of data related to different application domains, leading to another important research aspect, i.e., big data and cloud computing. Big data and cloud computing technologies in the logistics field have experienced initial contact, gradual penetration, and widespread application. Moreover, it supports traditional logistics to upgrade to smart logistics, aiming to achieve the fundamental requirements of today's logistics industry and reduce costs with enhanced efficiency. However, the big data and cloud computing wisdom logistics model still has many problems in the construction of logistics public information platforms, end coordination development, government platform construction, and so on, in order to solve the problems of low efficiency, high cost, and low service satisfaction of traditional logistics. In this article, we have designed a new big data-enabled logistics detection system that is based on B/S architecture, constructed a smart logistics model consisting of a supply subsystem, demand subsystem, and supervision subsystem, and finally realized the operation process of the smart logistics model based on big data cloud computing.

(Invited, Digital Presentation) Epitaxial Organic Molecular Interfaces As Well-Ordered Model Systems for Molecular Semiconductor p-n Junctions for Optoelectronic Applications

Donor-acceptor molecular interfaces are nothing but p-n junctions for organic optoelectronic devices such as organic light emitting diodes and organic solar cells where an exciton forms or dissociates. Understanding about dominating factors determining the intermolecular assembly and charge carrier exchange processes are highly anticipated for the establishment of smart design strategies of practically efficient devices. Molecular heterojunctions built on single crystal organic semiconductors provide well-ordered model systems disentangling complex intermolecular contacts in real devices. Moreover, the p-n junctions of highly ordered molecular assembly lead to the enhancement of the mobility of charge carriers and excitons through the inter-molecular delocalization of the electronic states, which potentially opens a new route for efficient optoelectronic applications of molecular semiconductors. In this contribution, crystallographic and electronic structures of well-ordered molecular semiconductor homo- and hetero-epitaxial junctions are overviewed.One representative system is a “complementary” p-n junction of perfluoropentacene (C22F14) crystalline ad-layers formed on the single crystal pentacene (C22H14) [1]. Grazing-incidence X-ray diffraction (GIXD) analyses revealed hetero-epitaxial growth of perfluoropentacene in a uniform crystallographic orientation with respect to the surface lattice of the single crystal pentacene. The energy-momentum dispersions of inter-molecular electronic bands were successfully demonstrated by angle-resolved photoelectron spectroscopy (ARPES) for the hetero-epitaxial perfluoropentacene as well as for the single crystal pentacene, which strongly suggests realization of the delocalization of electrons and holes across this well-ordered molecular p-n junction.To further improve the crystallinity of the epitaxial molecular heterojunctions, the authors’ group proposed a new concept of “quasi-homoepitaxial organic semiconductor junctions”, at which a molecular species with nearly identical in-plane lattice constants to those of the substrate molecular single crystal surface is stacked [2]. Actually, quasi-homoepitaxial crystallites of bis(trifluoromethyl)dimethylrubrene was revealed to form highly-ordered interface of much improved mean crystallite size on the single crystal surface of (unsubstituted) rubrene by means of high-resolution GIXD. The electronic structures exhibiting spontaneous electron transfer at this inter-molecular contact and possible opto-electronic applications of this quasi-homoepitaxial junction are also discussed in this presentation.This contribution is supported by Grant-in Aids for Transformative Research Areas (A) “Dynamic Exciton: Emerging Science and Innovation” (JSPS-KAKENHI Grant Number JP21H05405).[1] Y. Nakayama, et al., J. Phys. Chem. Lett. 10 (2019) 1312.[2] K. Takahashi, et al., J. Phys. Chem. Lett. 12 (2021) 11430.