Evaluation of contact and non-contact lap splices in concrete block masonry specimens

An experimental program was performed for qualitative and quantitative comparison of the maximum tensile resistance of contact and non-contact lap spliced bars in reinforced concrete block masonry using double pullout and wall splice specimens. A total of 32 specimens were tested, consisting of an equal number of double pullout specimens and full-scale wall splice specimens. Both specimen types had the identical cross-section. Eight replicate specimens for each specimen type were constructed with both contact and non-contact lap splice arrangements. Grade 400 deformed reinforcing bars with a 300 mm lap splice length were provided in all specimens. The double pullout specimens were tested applying direct tension to the lapped reinforcing bars. The splice resistance and displacement were recorded during testing. All double pullout specimens with contact lap splices developed, as a minimum, the yield strength of the reinforcing bars and generally displayed evidence of a yield plateau. In contrast, the double pullout specimens with non-contact lap splices failed when only 46.1% of the theoretical yield strength of the reinforcing bars was recorded as the maximum splice resistance. The difference between the average value of the tensile resistance in the contact and non-contact spliced bars was identified as being statistically significant at the 95% confidence level. Wall splice specimens were tested under a four-point loading arrangement with the lapped bars located in the constant moment region. The applied load and specimen deflection were recorded until failure occurred. A numerical analysis was then performed to calculate the maximum resistance of the spliced bars. The specimens with contact lap splices developed the theoretical yield capacity of the reinforcing bars. In contrast, the wall splice specimens with non-contact lap splices developed an average tensile resistance of 78% of the theoretical yield capacity. The difference between the average tensile resistances of the lapped bars in the two splice arrangements was identified as being statistically significant at the 95% confidence level. On average, the contact and non-contact lap spliced bars in the double pullout specimens developed 8.47% and 41.2% less tensile resistance, respectively, as compared to the wall splice specimens with the identical splice arrangement. Both differences were identified as being statistically significant at the 95% confidence level. Bond loss between the reinforcing bars and the surrounding grout was identified as the failure mode for both the double pullout and wall splice specimens with contact lap splices. In contrast, bond loss at the masonry block/grout interface was observed along the non-contact lapped bars in both specimen types, as identified by visual observations upon removal of the face shell and the surrounding grout. Based on the test results of the wall splice specimens with non-contact lap splices, a correction factor of 1.5 is suggested when calculating the effective splice length for the non-contact splice arrangement as tested

Ultra-broadband and polarization-insensitive metasurface absorber with behavior prediction using machine learning

The solar spectrum energy absorption is very important for designing any solar absorber. The need for absorbing visible, infrared, and ultraviolet regions is increasing as most of the absorbers absorb visible regions. We propose a metasurface solar absorber based on Ge2Sb2Te5 (GST) substrate which increases the absorption in visible, infrared and ultraviolet regions. GST is a phase-changing material having two different phases amorphous (aGST) and crystalline (cGST). The absorber is also analyzed using machine learning algorithm to predict the absorption values for different wavelengths. The solar absorber is showing an ultra-broadband response covering a 0.2–1.5 µm wavelength. The absorption analysis for ultra-violet, visible, and near-infrared regions for aGST and cGST is presented. The absorption of aGST design is better compared to cGST design. Furthermore, the design is showing polarization insensitiveness. Experiments are performed to check the K-Nearest Neighbors (KNN)-Regressor model’s prediction efficiency for predicting missing/intermediate wavelengths values of absorption. Different values of K and test scenarios; C-30, C-50 are used to evaluate regressor models using adjusted R2 Score as an evaluation metric. It is detected from the experimental results that, high prediction proficiency (more than 0.9 adjusted R2score) can be accomplished using a lower value of K in KNN-Regressor model. The design results are optimized for geometrical parameters like substrate thickness, metasurface thickness, and ground plane thickness. The proposed metasurface solar absorber is absorbing ultraviolet, visible, and near-infrared regions which will be used in solar thermal energy applications

DESIGN AND CHARACTERIZATION OF PHOTONIC CRYSTAL FIBER FOR SENSING APPLICATIONS

A simple structure of Photonic Crystal Fiber (PCF) for gas sensing and chemical sensing has been proposed in this paper. Index guiding properties of proposed PCF have been numerically investigated by using finite element method (FEM). From the numerical result, it is shown that the relative sensitivity and confinement loss depend on geomatrical parameters and wavelength. The relative sensitivity is increased by a increase of the diameters of central hollow core and innermost ring holes and confinement loss is decreased with a increase of the diameters of outermost cladding holes. By optimize the parmeters, the relative sensitivity is improved to the value of 20.10%. In this case, the confinement loss of the fiber is 1.09×10-3 dB/m

Electrical and Mechanical Properties of Sugarcane Bagasse Pyrolyzed Biochar Reinforced Polyvinyl Alcohol Biocomposite Films

Biochar obtained from the oxygen-deficient thermochemical processing of organic wastes is considered to be an effective reinforcing agent in biocomposite development. In the present research, biocomposite film was prepared using sugarcane bagasse pyrolyzed biochar and polyvinyl alcohol (PVA), and its electrical and mechanical properties were assessed. The biocomposite films were produced by varying content (5 wt.%, 8 wt.% and 12 wt.%) of the biochar produced at 400 °C, 600 °C, 800 °C and 1000 °C and characterized using X-Ray diffraction, scanning electron microscope, Fourier transform infrared spectroscopy. The experimental findings revealed that biochar produced at a higher pyrolyzing temperature could significantly improve the electrical conductance of the biocomposite film. A maximum electrical conductance of 7.67 × 10−2 S was observed for 12 wt.% addition of biochar produced at 1000 °C. A trend of improvement in the electrical properties of the biocomposite films suggested a threshold wt.% of the biochar needed to make a continuous conductive network across the biocomposite film. Rapid degradation of tensile strength was observed with an increasing level of biochar dosage. The lowest tensile strength 3.12 MPa was recorded for the film with 12 wt.% of biochar produced at 800 °C. Pyrolyzing temperature showed a minor impact on the mechanical strength of the biocomposite. The prepared biocomposites could be used as an electrically conductive layer in electronic devices

Recent advances in biosensors for detection of COVID-19 and other viruses

This century has introduced very deadly, dangerous, and infectious diseases to humankind such as the influenza virus, Ebola virus, Zika virus, and the most infectious SARS-CoV-2 commonly known as COVID-19 and have caused epidemics and pandemics across the globe. For some of these diseases, proper medications, and vaccinations are missing and the early detection of these viruses will be critical to saving the patients. And even the vaccines are available for COVID-19, the new variants of COVID-19 such as Delta, and Omicron are spreading at large. The available virus detection techniques take a long time, are costly, and complex and some of them generates false negative or false positive that might cost patients their lives. The biosensor technique is one of the best qualified to address this difficult challenge. In this systematic review, we have summarized recent advancements in biosensor-based detection of these pandemic viruses including COVID-19. Biosensors are emerging as efficient and economical analytical diagnostic instruments for early-stage illness detection. They are highly suitable for applications related to healthcare, wearable electronics, safety, environment, military, and agriculture. We strongly believe that these insights will aid in the study and development of a new generation of adaptable virus biosensors for fellow researchers

Recent advances in biosensors for detection of COVID-19 and other viruses

This century has introduced very deadly, dangerous, and infectious diseases to humankind such as the influenza virus, Ebola virus, Zika virus, and the most infectious SARS-CoV-2 commonly known as COVID-19 and have caused epidemics and pandemics across the globe. For some of these diseases, proper medications, and vaccinations are missing and the early detection of these viruses will be critical to saving the patients. And even the vaccines are available for COVID-19, the new variants of COVID-19 such as Delta, and Omicron are spreading at large. The available virus detection techniques take a long time, are costly, and complex and some of them generates false negative or false positive that might cost patients their lives. The biosensor technique is one of the best qualified to address this difficult challenge. In this systematic review, we have summarized recent advancements in biosensor-based detection of these pandemic viruses including COVID-19. Biosensors are emerging as efficient and economical analytical diagnostic instruments for early-stage illness detection. They are highly suitable for applications related to healthcare, wearable electronics, safety, environment, military, and agriculture. We strongly believe that these insights will aid in the study and development of a new generation of adaptable virus biosensors for fellow researchers

Teorijski okvir marketinga odnosa i suradnje na poslovnom tržištu

Purpose – This paper addresses the issues related to the practice of relationship marketing at the organizational level. Considering the influence of various factors, this study offers a theoretical framework necessary to create, maintain, and enhance the business relationship. Design/methodology/approach – The research is based on a systematic review of existing literature, including journal articles, subject-specific professional websites, and textbooks on relationship marketing. Literature reviews relating to the Nordic School, Industrial Marketing and Purchasing (IMP) Group Approach, and the North American School are included. Findings – The relationship marketing approach has evolved since the pre-industrial era, and more organizations are embracing this marketing stance in the current, post-industrial era. A theoretical framework that consists of influential variables for creating, maintaining, and enhancing relationships is proposed to explore this multidimensional construct. Information on proper conditions is synthesized to help marketers identify an appropriate environment for implementing this approach in the business context. Limitations – Given the increasing complexity of relationship marketing and the increasing need to understand this approach, the proposed theoretical framework could be useful for improving the understanding of multi-dimensional aspects of relationship marketing. Consequently, directions for future research in relationship marketing are identified. Originality/value – This study provides a coherent picture of relationship marketing viewed through the proposed theoretical framework, based on a systematic literature review. Specifi cally, it is probably a first instance in which a paper sought to address the practice of relationship marketing by including tripartite areas – namely, creating, maintaining, and enhancing relationships in a Business to Business (B2B) setting, which is scattered across various disciplines.Svrha – U radu se istražuju problemi vezani uz praksu marketinga odnosa i suradnje na organizacijskoj razini. Uzimajući u obzir utjecaj različitih faktora, rad nudi teorijski okvir za stvaranje, održavanje i unapređenje poslovnog odnosa. Metodološki pristup – Istraživanje se temelji na sustavnom pregledu postojeće literature uključujući znanstvene članke iz časopisa, tematski vezane profesionalne web stranice i udžbenike o marketingu odnosa i suradnje. U pregled literature uključeni su pristupi istraživačkih inicijativa Nordic School, Industrial Marketing and Purchasing (IMP) Group te North American School. Rezultati i implikacije – Marketing odnosa i suradnje razvija se od predindustrijskog do poslijeindustrijskog vremena, a sve više organizacija prihvaća ovaj pristup. Za ovaj je multidimenzionalni konstrukt predložen teorijski okvir koji se sastoji od utjecajnih varijabli za stvaranje, održavanje i poboljšanje odnosa. Sintetiziraju se informacije o odgovarajućim uvjetima koje bi marketinškim stručnjacima pomogle u pronalasku odgovarajućega okruženja za provedbu ovoga pristupa u kontekstu poslovnog tržišta. Ograničenja – S obzirom na sve veću složenost marketinga odnosa i suradnje vis-à-vis sve veće potrebe za razumijevanjem pristupa, predloženi bi teorijski okvir bio koristan za bolje razumijevanje multidimenzionalnih aspekata marketinga odnosa i suradnje. Slijedom toga, utvrđeni su pravci za buduća istraživanja u marketingu odnosa i suradnje. Doprinos – Rad pruža koherentnu sliku marketinga odnosa i suradnje promatranoga kroz predloženi teorijski okvir, temeljen na sustavnom pregledu literature. Konkretno, ovo je vjerojatno prvi put da se rad pokušao baviti praksom marketinga odnosa i suradnje uključivanjem tripartitnog područja - stvaranjem, održavanjem i poboljšanjem odnosa u poslovnom (B2B) području koje je raspršeno po različitim disciplinama

Classification and prediction of dengue fever from microarray samples by LDA based on PPI network

Modern Bioinformatics tools have a tremendous contribution in gene analysis, Protein-Protein Interaction (PPI) Network creation and Drug design. It's been a big challenge to pick out a small subset of informative data from a large microarray dataset and reach on an accurate classification. A successful and precise classification of any disease into its subtype is necessary for successful diagnosis and treatment of the disease. The NCBI Gene Expression Omnibus (GEO) is the extensive storage containing experimental microarray data. In this research, PPI networks and a common drug is designed for the unique DENGUE samples and Linear Discriminant Analysis (LDA) and Principle Component Analysis (PCA) techniques are applied for the classification of Dengue fever genes into its unique samples. Comparing to PCA, in LDA, LD1 classifies 96.2% while PC1 Classifies 46%. Using LDA, also a prediction is made to predict samples from gene variance. Moreover, LDA predicts approximately 73.21% accurate results. All of the calculation, comparison and gene analysis is performed using R tool and UniHi tool is used for the creation of PPI network and Drug design. Here, a common drug is designed which can be used for all of the sample type of the Dengue fever but in different proportion