bluuebunny/crossref_metadata_2025 huggingface dataset:
Adsorption interaction model of adsorbents white sand with heavy metals cadmium (Cd2+) naturally
Authors: Haryanto B , Saragih FT , Sinaga W K , Turmuzi M , Misran E
Published: June 2020

This study aimed to analyze the adsorption ability of white sand in the metal ions adsorb cadmium (Cd2+) with a concentration of 70 ppm to a solution with a pH of 4.5. The white sand is used is 40 mesh. This research was conducted by batch adsorption operation naturally and adsorption kinetics modeling. Kinetics of adsorption reached equilibrium at time t = 120 minutes with the percentage concentration of adsorbed Cd2+ 30.7%. In the adsorption kinetics modeling correlation coefficient is almost the same between the equations of first order and second order in the amount of 0.97 and 0.99. The result indicated that the type of interaction Cd2+ ions on the surface of white sands occur in chemistry and physics. The adsorption kinetics of diffusion modeling of internal and external diffusion of the correlation coefficient has 0.95 and 0.85. From this data it can be seen that in this study is modeling kinetic internal diffusion trend that shows adsorbent particles are inter sand surface area that experienced internal inter-particle pore diffusion.
Properties of unsaturated polyester composite filled with cellulose from peanut shell (Arachis hypogea I.): the effect of filler content and compatibilizer addition
Authors: Nasution H , Kosasih K , Maulida  , Al Fath M T
Published: June 2020

Unsaturated polyester (UPR) composite containing the powder of peanut shell fiber filler is a panel product made by compacting the particles of peanut shell powder and binding them with UPR. The purpose of this research is to investigate the effect of peanut shell fiber powder cellulose filler composition and addition of compatibilizer on the tensile properties, energy impact and water absorption of UPR composites. The composites were made of UPR as matrix and mixed with peanut shell powder as filler, with methyl ethyl ketone peroxide catalyst, and molded by using compression molding method. The result of the physical properties test supported by FTIR characterization of the composite showed that the filler was dispersed into the matrix with the formation of a new wave from 3463 to 3495 cm-1. The best of tensile and impact properties were found on 5% filler and 4% of compatibilizer composition with the tensile strength of 26.04 MPa and an energy impact of 99.82 MPa. The results obtained have been supported by Scanning Electron Microscopy (SEM) analysis that there was resistance from the composite when the impact was applied. The water absorption of composite tended to rise with the increasing amount of filler.
Effect of preheat and post heat on mechanical properties of 6061 aluminium tungsten inert gas welded joints
Authors: Hamsi A , Sitorus T B , Sinaga R K
Published: June 2020

Tungsten inert gas (TIG) welded joints of 6061 aluminium are often used in the fuel tanks of large launch vehicles, because of the massive loads these vehicles carry, dealing with weld reinforcement on TIG joints represents an important issue in their preheat and post heat on mechanical properties. Experimental and calculation methods were used to investigate the effect of weld preheat and post heat on the mechanical properties of these joints. The purpose of this study was to determine the effect of preheat and post heat on mechanical properties of 6061 aluminium. The experimental result indicated that mechanical properties of Al 6061 of the welding changed. The hardness of weld metal increase in temperature 130°C = 68,72 BHN, in 160°C = 70,51 BHN, and in 190°C = 76,26 BHN. Tensile strength also increase in temperature 130°C = 158,57 N/mm2, in 160°C = 169,85 N/mm2, in 190°C = 174,50 N/mm2.
Comparison of weight loss in natural rubber latex film (rubber dam) filled nanocrystal cellulose and synthetic dyes with soil burial methods
Authors: Harahap Hamidah , Wangi Yoeselyn , Chandra Toni , Halimatuddahliana
Published: June 2020

Biodegradation of natural rubber latex products filled with nanocrystal cellulose from peanut shell is carried out by soil burial methods with and without using fertilizer. Testing is done by calculating the loss of sample weight for 5 weeks with observation every 1 week. Samples were tested the morphology using Scanning Electron Microscope (SEM) and Fourier Transform Infra Red (FTIR). Natural rubber latex film samples showed that the loading of nanocrystal cellulose fillers from peanut shells was biodegradable faster in soil burial method with addition of fertilizer in soil compared to no addition of fertilizer.
Physical and mechanical properties of natural rubber latex film (Rubber Dam) products with filler nanocrystal cellulose from peanut shell (Arachis hypogea L.) and synthetic dyes
Authors: Chandra Toni , Harahap Hamidah , Wangi Yoeselyn , Halimatuddahliana
Published: June 2020

Rubber dam is considered as an ideal device for tooth isolation. Rubber dam is one of example product from natural rubber latex. Peanut shell is one of the industrial waste containing 35,7% of cellulose. Nanocrystal cellulose from peanut shell can be an alternative waste utilization and have potential as filler in natural rubber latex films. Studies about effect of loading nanocrystal crystal as filler on natural rubber latex films with polyvinyl pyrrolidone (PVP) and using synthetic dyes have been carried out on crosslink density and mechanical properties such as tensile strength, elongation at break and tensile modulus. The process begins with pre-vulcanization of natural rubber latex at temperature 70°C with 0, 2, 4, 6, 8 gram of filler loading and followed by vulcanization at 120°C for 10 minutes. The results obtained with loading nanocrystal crystal filler using synthetic dyes for physical properties, crosslink density, will increase with the increase of filler loading. For mechanical properties, tensile strength and tensile modulus will increase with greater filler loading, while elongation at break will decrease. The best results are obtained for mechanical properties of natural rubber latex film products using synthetic dye on 6 gram nanocrystal cellulose of filler loading.
The analysis of tensile strength and elasticity in slag concrete with curing variations at 90 days age
Authors: Karolina R , Handana M A P , Inanda R , Wiranti A D
Published: June 2020

Cement is a concrete constituent material that has a great influence on concrete quality, both normal and high-quality concrete. High quality concrete in SNI 03-6468-2000 is defined as concrete which has compressive strength characteristics above 41.4 MPa. During the process, cement produces gas emissions obtained from combustion, calcination of limestone, and the use of electrical energy. The purpose of using cement in the preparation of concrete itself is as a binder between aggregates. Nowadays, commonly used cement (OPC cement) can be replaced with slag cement. Slag cement is the result of the addition of Granulated Blast Furnace Slag into the final grinding of cement which is a waste product from the steel ore smelting process. This research is comparing the magnitude of the tensile strength and the modulus of elasticity of the samples with 100% OPC cement and those with 100% slag cement. The samples used were cylinders with 15 cm diameter and 30 cm height. The tests were carried out when the concrete reaches 90 days age. The curing of the samples was carried out with four variations which is by submerging those in tap water, Kuala Tanjung sea water, Sulphuric Acid water, and compound curing. The results of this test were obtained if the slag cement-used concrete is able to have a tensile strength that is almost the same as OPC cement-used concrete which is 4.341 MPa for normal concrete and 4.293 MPa for slag concrete and its modulus of elasticity of 46103.67 MPa for normal concrete and 46892.82 MPa for slag concrete.
Economic analysis of port development project (case study: Belawan Port Medan)
Authors: Nurul Huda Listiani , Sulastri Ratih
Published: June 2020

Belawan Port is one of the most important ports on the island of Sumatra. Port conditions are currently only able to load ships with a maximum draft of 8.9 m for normal water level conditions. This condition greatly limits the productivity especially for large ships. Therefore, the access channel deepening project is proposed to improved loading and unloading activities. This study was conducted to assess the benefits received from the project. The study was conducted with the parameters EIRR (Economic Internal Rate of Return), NPV (Net Present Value), and PI (Provitability Index). Furthermore, it also conducted a study to make the Port of Belawan port become sustainable. After analysis, the value of EIRR is 23.53% and NPV is 622,586,691 USD, and PI is 3.99. These results showed that the project has the proper parameters even when the sensitivity analysis I done with the benefit reduce to 70% and cost at fixed. But to get a sustainable port predicate still needed some adjustments, especially in terms of preserving the natural environment in which the parameter is still below the standard. Necessary measures such as the provision of a special budget for green port adjustment programs and policies and the provision of facilities to support the program.
Evaluation the effect of supply chain management on firm performance in passion fruit syrup company
Authors: Febrina Kodrat Kimberly , Sinulingga Sukaria , Napitupulu Humala , Ampuh Hadiguna Rika
Published: June 2020

In fact, supply chain management can not only be applied by large enterprises but also by Small and Medium Enterprises. One of them is Small and Medium Enterprise of Passion fruit. Passion fruit (passifloraceae) is one of the strategic commodities because of its usefulness as raw material of passion fruit syrup as an agroindustry product that has rich nutritional value of vitamin C which is beneficial to human health. This research has five elements of supply chainnamely : farmers, suppliers, extract agroindustry, passion fruit syrup agroindustry, and retailers.The objective of this study is to analyze whether there is a significant influence between Supply Chain Management on firm performance. This type of research was a causal research. Data collection used questionnaire. The result of multiple linear regression analysis, it showed that the variable of process integration has the biggest influence to variable of enterprise SCM performance (dependent) with coefficient value equal to (0,289), then variable of satisfaction with value (0,058), variable of trust (0,286), communication variable (0,184), dependency variable (0,021) and having the least was the variable of influence and commitment (0,080). This means that the five independent variables have a positive and significant influence on the dependent variable.
Micro, Small and Medium Enterprise strategy to improve competitiveness in the era of the ASEAN economic community (AEC)
Authors: Fernanda Putri Widya , Sinulingga Sukaria , Hidayati Juliza
Published: June 2020

The Asean Economic Community or AEC in Indonesia has been in effect since 2015. The establishment of the MEA itself is carried out in order to increase ASEAN’s competitiveness and be able to compete with China and India to attract foreign investment. This foreign investment is needed to increase employment and improve welfare. MEA, the goal to be achieved is the free flow of goods, services, and trained labor, and a freer flow of investment. With the enactment of the AEC in Indonesia in 2015 will provide some challenges both at home and competition with fellow ASEAN countries and other countries outside ASEAN such as China and India. This competition will have an impact on competitive prices as well, not only the superior commodities / products / services of large industries (UB), but also the Micro, Small and Medium Enterprises (MSME) sector.
The possibility of smartphone camera to determine iron(III) in solution
Authors: Rosyida N , Dinira L , Wulandari E R N
Published: June 2020

Determination of iron in solution is usually done by using instruments, such as Atomic Absorption Spectrophotometer (AAS) and UV-Visible Spectrophotometer. However, the availability and the use of these instruments in Indonesia is limited due to the expensive price. Nowadays everyone has smartphone with advanced camera features. This study focuses on the determination of iron (III) using a non-instrument method, namely digital image colorimetry. This method is using smartphone camera to capture the digital image of sample. Smartphone cameras used on this study are based on Android operating system with the specification of 16-megapixel and OS operating system with the specification of 12-megapixel. Digital images that has been captured by smartphone camera are processed using MATLAB to determine the RGB intensity. The image processing results then compared with the results from UV-Visible spectrophotometer. The result shows the linearity of the RGB color calibration curve from the smartphone camera is on a part with the calibration curve that generated by the UV-Visible spectrophotometer. This indicates that smartphone camera has a possibility to determine iron (III) in solution by using digital image colorimetry.
Balanced scorecard in the integration of corporate strategic planning and performance: a literature review
Authors: Alqili Laury Hanni , Matondang Nazzaruddin , Tryana Sembiring Meilita
Published: June 2020

The purpose of this paper is to review the model literature Balanced Scorecard (BSC) from 2008 to 2017 in order to provide reference guidance to researchers, particularly with regard to the context and focus of previous research, and various methodology approach to the assessment of performance measurements from the perspective of Balanced Scorecard. The primary objective of this study is to analyze the application of BSC in various specific areas, as well as investigating its extension. The methodology used in this study is a literature review of published articles. The searching of the literature was conducted based on research objectivity from an online search of relevant literature. The findings from the review are summarized. Then, the authors have an analysis of the identified articles.
Design of E-office system in vocational school Diponegoro University using code igniter framework
Authors: Subari A , Manan S , Ariyanto E
Published: June 2020

E-Office is an administrative and centralized component of the organization where data, information and communication are stored and disseminated through several forms of telecommunications. The main advantage of the E-Office system is that it can reduce paper usage. The other advantages are centralized data store, quickly data access, accurately and real time using the internet network and can make reports quickly based on existing data. With all the advantages of E-Office system, Vocational School of Diponegoro University is committed to using its services, especially in the process of managing correspondence documents. It is necessary to design and create an application based on E-Office that is used at Vocational School of Diponegoro University. This research is intended to build an application or information system based on E-Office system to handle the management of correspondence documents at the Vocational School of Diponegoro University by utilizing web-based applications. Information system design uses MVC concept on code igniter framework. With E-Office system, management of correspondence documents can be done more quickly and can be done anywhere. The impact is that service time for stakeholders is becoming faster.
Dashboard information system development as visualization of transaction reports in the application BackInd (backpacker reservation system)
Authors: Lubis Muharman , Dennis Filhan , Andreswari Rachmadita , Ridho Lubis Arif
Published: June 2020

The accuracy and clarity of information becomes primary source for decision making process to bring effective and efficient of technology utilization. For this purpose, the ‘BackInd’ has been developed as reservation system to help travellers obtain complete information regarding the tourist attractions and any relevant information. Therefore, there are several problems that occur in term of presenting information, such as the use of complex tables as a means of detail information about business conditions, information overload in single page that become deterrent in term of identification of relevant data and unintuitive data presentation that bring exhaustive understanding. Thus, the implementation of dashboard can visualize the key performance and metric in real-time to support the executive gain valuable insight lead to quick and accurate decision making. The results of this study related to the process and context analysis by visualizing the data group into various sections such as transactions, finances, testimonials, visits and business performance to bring resourceful and usable information.
Effect of TiO2 additive volume fraction in lubricant oil on the performance of hydrodynamic journal bearing
Authors: Singh Anurag , Verma Neeraj , Chaurasia Aman , Kumar Alok
Published: June 2020

Hydrodynamic journal bearings are widely used in rotating machines where high loading condition prevails. In this work, effect of different volume fractions of TiO2 (Titanium dioxide) additive in commercially available SAE30 lubricant oil on the performance of hydrodynamic journal bearing is analysed experimentally. Hydrodynamic journal bearing test rig is used to perform the experiment. The experiment is carried out by taking different volume fractions of TiO2 additive (0.075%, 0.1% and 0.15%) in SAE30 lubricant base oil and their effect on journal bearing characteristics like coefficient of friction, pressure distribution, temperature rise, eccentricity ratio, attitude angle, minimum film thickness and displacement is analysed. Paraffin oil is used to uniformly distribute the TiO2 in the base oil and to resist sedimentation.

The study shows that the addition of TiO2 additive in the base SAE30 lubricant oil is capable of significantly reducing the values of friction coefficient and maximum temperature rise. It has been found that the addition of TiO2 additive improves the performance of the hydrodynamic journal bearing. Results reveals that the additive performs better at higher loading conditions.
Synthesis and characterization of CZTS thin films from compound target deposited by RF sputtering method
Authors: Abdullahi S , Momoh M , Moreh AU , Bayawa AM , Saidu A
Published: June 2020

A potential way to improve the quality of Copper-Zinc-Tin-Sulfide (Cu2ZnSnS4(CZTS) absorber thin film by one step process of Radio Frequency (rf) sputtering using a single compound target is proposed for thin film solar cells. Structural and Optical characterizations were carried out using X-ray Diffractometer, Raman spectrophotometer and UV-VIS spectrophotometer. The X-ray diffraction analysis showedhklplanes of (002), (110), (112) and (212). Raman results confirmed the existence of secondary phases of SnS, Cu2-xS and CTS. The optical absorption coefficient of the thin film was found to be greater than 104cm−1indicating a direct band gap nature of the samples. The optical band energy was calculated and found to be in the range of 1.51eV to 2.4 eV. The band gap energy obtained is more appropriate for photovoltaic applications.
Antimicrobial and antioxidant activities of algal-mediated silver and gold nanoparticles
Authors: Omomowo I O , Adenigba V O , Ogunsona S B , Adeyinka G C , Oluyide O O , Adedayo A A , Fatukasi B A
Published: June 2020

This study focused on the synthesis and application of nanoparticles using Neodesmus pupukensis (MG257914). Cell free extracts of the microalga was employed to synthesize both silver (AgNPs) and gold nanoparticles (AuNPs). The nanoparticles were characterized using UV-visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), and Scanning electron microscopy (SEM). The nanoparticles were screened for their antimicrobial potential and free radical scavenging activity against stable free radical (2,2-diphenyl-1-picrylhydrazyl). The UV absorption spectra showed absorbance peaks of 430 nm and 530 nm for AgNPs and AuNPs respectively. The FTIR spectra at 3283, 2102.87, 1636.02 for AgNPs and 3264.86, 2104.49, 1636.62, 1232.39, 1028.97 cm−1 for AuNPs confirms the participation of proteins in the capping and stabilization of the nanoparticles. The zone of inhibition indicating the activity of the NP-AgNPs were: Pseudomonas sp (43 mm); Escherichia coli (24.5 mm); Klebsiella pneumoniae (27 mm), Serratia marcescens (39 mm) while AuNPs showed activity to only Pseudomonas sp (27.5 mm) and Serratia marcescens (28.5 mm). The antifungal potency of NP-AgNPs was confirmed with mycelial inhibition of 80.6, 57.1, 79.4, 65.4 and 69.8% against Aspergillus niger, A. fumigatus, A. flavus, Fusarium solani and Candida albicans respectively, while NP-AuNPs had 79.4, 44.3, 75.4, 54.9 and 66.4% against A. niger, A. fumigatus, A. flavus, F. solani and C. albicans respectively. Appreciable free radical scavenging properties was obtained with NP-AuNPs (68.9%) and NP-AgNPs (41.21%). The nanoparticles of Neodesmus pupukensis showed appreciable potential as antimicrobial and antioxidant agents and could be explored for various applications in biotechnology.
Antioxidant and antimicrobial activities of nanosilver-mycomeat composite produced through solid state fermentation of tigernut waste and cassava pulp by Pleurotus pulmonarius
Authors: Bamigboye C O , Amao J A , Fadiora I A , Adegboye J D , Akinola O E , Alarape A A , Oyeleke O R , Adebayo E A
Published: June 2020

Bacterial deterioration is one of the most critical subjects in the production, processing, transport, and storing of food. The search for novel materials for the synthesis of nanoparticles is unending and this is likely to continue in the upcoming years. In this study, mycomeat samples were produced using cassava pulp (C) and tiger nut aggregate waste (T). The mycomeat extracts were used to produce nanosilver-mycomeat by catalytic conversion of Ag+to Ag0. The antioxidant and antimicrobial activities of the nanosilver-mycomeat composites were determined using established methods. The nanosilver-mycomeat composites of both C and T showed increased antioxidant and antimicrobial activities compared to the ordinary mycomeat extract. This can find applications in the packaging of food, thereby preventing food samples from deterioration.
Assessment of growth performance, nutrient utilization and haematological profile of Clarias gariepinus fed with nanoselenium formulated diets
Authors: Owolabi OD , Babarinsa MK
Published: June 2020

A 63-day experiment was conducted to determine the effects of nanoselenium formulated diets on growth performance, nutrient utilization and haematological profile of Clarias gariepinus. Fish were acclimatized for 14 days, 10 fish each were randomly introduced into different troughs. Feed supplemented with nanoselenium at 2 mg/kg, 4 mg/kg and the control without nanoselenium were fed to group of fish each in triplicate. The feed intake, weight gain, food conversion ratio (FCR), specific growth rate (SGR), protein efficiency ratio (PER) and survival rate (SR) were determined, also the haematological profile of Clarias gariepinus fed were analyzed. There were significant increase (p<0.05) in the weight gain of fish fed 2 mg/kg of nanoselenium as compared with those fed 4 mg/kg of nanoselenium and the control. Similarly, PER and SR were significantly higher (p<0.05) in 2 mg/kg when compared with other formulated diets. The FCR of fish fed 2 mg/kg was significantly lower compared with 4 mg/kg nanoselenium formulated diets. WBC, RBC, haemoglobin, and haematocrit significantly increased in fish fed 2 mg/kg of nanoselenium as compared with those fed 4 mg/kg nanoselenium and the control group while there was variation in the values of other haematological parameters such as platelets, MCV, MCH and MPV. The research indicated that dietary inclusion of nanoselenium at 2 mg/kg may enhance better growth performance and nutrient utilization of Clarias gariepinus.
Recent developments on the photoanodes employed in dye-sensitized solar cell
Authors: Shittu H A , Bello I T , Kareem M A , Awodele M K , Sanusi Y K , Adedokun O
Published: June 2020

The emergence of dye sensitized solar cell (DSSC) as an alternative device for silicon based solar cell has gained a lot of attention from researchers due to its cost-effective, easy fabrication and environmentally friendliness. Photoanodes are semiconductor and as one of the four components of DSSC plays a major role for dye loading and electron conduction. A good photo anode should provide an efficient surface area in dye loading, nanostructure for high light harvesting opportunity, fast electron transport ability and good band gap architecture. Several nanostructures materials have been studied and employed as photoanode in DSSC. They include TiO2, ZnO, Nb2O5, SnO2, among others. The problem associated with photoanodes used in fabricating DSSC is high recombination rate of electrons that emanate from the number of grains. The dispersed nature of progress reports on developments of photoanodes calls for summary. Hence this review gives a general summary of the progress made in various materials used as photoanode in DSSC and the methods adopted in synthesizing them. In this present review, our attention is not only on synthesis and characterization of the materials alone but also on the effect of different factors influencing photovoltaic characteristics of photoanode for DSSC application.
Surface sterilization of Ocimum seeds and tissues with biosynthesized nanosilver and its effects on callus induction
Authors: Adebomojo AA , AbdulRahaman AA
Published: June 2020

Plant tissue culture is a basic and fundamental component of plant biotechnology. Nowadays, nanomaterials especially nanosilver (NS) are being used as an antimicrobial agents for surface sterilization of explants in tissue culture. In this study, biosynthesized nanosilver (BNS) was used for the surface sterilization of Ocimum seeds and tissues and its effects on callus induction were evaluated. The seeds and tissues were exposed to different concentrations of BNS (10, 50 and 100 mg/l) as well as 5% Clorox for five exposure times (5, 10, 20, 30 and 60 min) and effects on germination, callus induction and surface sterilization were determined. The BNS was found very effective on surface sterilization as 100% decontamination was achieved with no adverse effect on explant viability and callus formation but rather had stimulating effect on formation of callus. The study concluded that BNS can be used as an antimicrobial agent in surface disinfection of explants therefore extending the frontiers of the potential application of biosynthesized nanosilver in tissue culture.
Experimental study, phenomenological and adaptive neuron analysis of creep property of Momordica augustisepala L nanofiber reinforced polyvinyl alcohol polymer film composite
Authors: Adeyi A J , Durowoju M O , Adeyi O
Published: June 2020

The viscoelastic property of packaging material affects foods’ postharvest management and biophysical quality preservation of food. This study investigated the creep viscoelastic property of neat polyvinyl alcohol film and polyvinyl alcohol film reinforced Momordica augustisepala nanofiber composite. The applicability and comparison of Burger phenomenological and Adaptive neuron model to analyze the creep data were investigated. The instantaneous modulus and creeping speed of neat and reinforced polyvinyl alcohol were 7.53710 MPa, 10.27580 MPa and 3.00590 MPa.s, 2.85391 MPa.s, respectively. The coefficient of determination of Burger model prediction was 0.99889 and 0.99972 for neat and composite polyvinyl alcohol film, while the coefficient of determination of Adaptive neuron model was 0.99986 for both neat and reinforced polyvinyl alcohol film. The Momordica augustisepala nanofiber improved the creep viscoelastic property of polyvinyl alcohol film and Adaptive neuron model showed superiority over Burger model in prediction of experimental data. The results are vita in material design, life prediction and usage prescription.
Isolation and characterization of cellulose nanofibres from three common Nigerian grasses
Authors: Ejeta KO , Azeez TO , Banigo AT , Nkuma-Udah KI , Ajuogu E
Published: June 2020

Nanocellulose may be in nanocrystal or nanofibre form which may be extracted from purified cellulose by different methods. These include methods like dual-opposite-spinneret electrospinning, mechanical methods, a combination of chemical and mechanical methods, cryocrushing and enzymatic approaches. Nitrocelluloses have been extracted from various plants but not much has been reported on the yield from grasses. In this study, cellulose nanofibres (CNFs) were extracted from three common grasses;Pennisetum purpureum, Cynodon dactylonandAxonopus compressusby formic acid hydrolysis with the micrograph of CNF for each grass obtained. The CNFs are web-like long fibrous structure with diameter ranging between 3 to 5 nm and yield of over 75%. The crystallinity index averaged 76% and the onset temperature of thermal decomposition was 199 °C. Thus,Pennisetum purpureum, Cynodon dactylonandAxonopus compressusare good eco-friendly sources of CNF for potential application as new source of nanofillers for reinforcement of nanocomposite films.
Facile synthesis of silver nanoparticles using leaf extract of Hyptis suaveolens (L.) Poit for environmental and biomedical applications
Authors: Lateef A , Oladejo S M , Akinola P O , Aina D A , Beukes L S , Folarin B I , Gueguim-Kana E B
Published: June 2020

Aqueous leaf extract of Hyptis suaveolens was investigated to synthesize silver nanoparticles (Hs-AgNPs). Biomolecules such as phenolics, proteins, carbohydrates and esters facilitated bioformation of Hs-AgNPs with ƛmax at 420 nm. The nearly spherical Hs-AgNPs were polydispersed and sized 29.19-52.27 nm with yield of 85.8 %. Hs-AgNPs showed potent inhibition of 75.22-100 % against multidrug resistant bacteria, and fungal growth inhibition of 73.33-100 %. Hs-AgNPs scavenged DPPH and H2O2 by 77.75-83.19, and 54.21-70.11 % respectively. It also effectively inhibited coagulation of blood. The study established the nanobiotechnological importance of H. suaveolens, with bioformation of AgNPs that have potent activities for environmental and biomedical applications.
Fibrous Orientation Effects on the Deformation and Stress of a Pigeon-like Flapping-wing Micro Aerial Vehicle Based on APDL
Authors: Atik Morshed A K M , Yu Chunjin , Wang Fang
Published: June 2020

Fibrous orientation effects on the deformation and stress of a bird-like (pigeon) composite wing was studied. The bird wing is simulated and modeled by mechanical APDL software. The stress and displacement results of bird wing model under different laying modes are obtained by finite element method. The optimal laying mode is analyzed. The results are checked by strength theory in composite mechanics. The results show that for singe orientation [-20]4 is the best orientation. For 4 layers structure, [-45/90/0/45] has best performance in 1st layer while [45/0/-45/90] has worst performance; [0/-45/90/45] has best performance in 2nd layer while [0/45/-45/90] has worst performance. [45/90/-45/0] has best performance for pigeon wing in this design in 3rd layer while [-45/0/90/45] has worst performance. [45/0/90/-45] has best performance for pigeon wing in this design in 4th layer while [-45/90/0/45] has worst performance. By comparison, it is found that the different-direction pavement is better than the same-direction pavement.
A Novel Hand Pallet Truck and Multi-objective Optimization Design of It’s Lifting Mechanism
Authors: Yang Bo , Yuan Jianhui , Chen Min , Yu Fenhua
Published: June 2020

Hand pallet truck is widely used to carry baggage and cargoes in daily life and work. However, rotary-lift based luggage hand pallet truck is inconvenient to handle and difficult to carry heavy goods. Hydraulic cylinder based hand pallet truck is also used commonly, but its lifting speed is not fast enough. In addition, most of them can’t save energy. To this end, a novel rotary-lift based hand pallet truck is proposed. Auxiliary and cushioning forces are provided by gas springs. Its lifting height is adjustable. Critically, its lifting mechanism can be locked automatically after ascending or descending into the target positions. Thus, it’s easy for just one person to operate. Aiming at saving time, force and energy, a multi-objective optimization design model for the lifting mechanism is built, based on which most key parameters and dynamics indexes can be calculated. Numerical analysis and experiment results show that the proposed model is effective and the design scheme of the novel hand pallet truck is feasible.
Development Research and Crucial Technology Analysis of Scaled 3-Bearing Swivel Duct Nozzle Rotary Drive System
Authors: Qi Hao , Yang Xiao , Wang Zehe , Zhu Huajuan
Published: June 2020

The 3-bearing swivel duct (3BSD) nozzle for short-range/vertical take-off and landing(S/VTOL) fighters is a crucial component for aircraft to achieve vertical and/or short take-off and landing, which significantly improves the manoeuvre ability of the aircraft, while the nozzle rotary drive system is the crucial technology for S/VTOL functions which has significant impact on the fighter performance. Based on the principle and characteristics of the 3BSD nozzle, this paper systematically reviews the development and evolution of the 3-bearing swivel duct nozzle, and analyses and summarizes the types and characteristics of the 3BSD nozzle rotary drive system. Three crucial technologies of the 3BSD nozzle rotary drive system are evaluated and discussed in detail. Suggestions on future research and development of equipment are given.
Kinematics analysis and optimization of 6R manipulator
Authors: Li Qidong , Ju Hehua , Xiao Pengfei
Published: June 2020

In order to solve the problem of 6R manipulator kinematics, this paper analyzes the inverse kinematics solution and optimizes the solution process of forward kinematics. Aimed to the structural characteristics of the manipulator, this paper first introduces the concept of the natural invariants, establishes the Denavit-Hatenber (D-H) model based on the natural invariants and proposes a new iterative algorithm for manipulator forward kinematics. Then, the inverse kinematics based on the natural invariants is proposed, which is divided into the position inverse solution and the inverse attitude solution, and the analytical solution is obtained by analyzing the singularity of the solution. Finally, the visual simulation model is built with MFC and Coin4D. The simulation results show that the proposed forward and inverse kinematics method of the six-degree-of-freedom manipulator has small error and high efficiency, and the accuracy and real-time performance of the algorithm are verified.
Numerical Study on the Effectiveness of Vectoring Primary Flow with Dilator by Using Microjet Actuator
Authors: Gao Feng , Zhang Qian , Chen Fengli , Zhang Chengtao
Published: June 2020

In the present paper, orient control of dilator primary flow in microjet were simulated numerically by using microjet actuator with the X-L whole flow field calculation model. The effects of different expansion half angles of the primary flow channel, microjet actuator amplitude, micro jet actuator frequency, and the position of micro jet actuator and primary flow velocity on deflection of primary flow were analyzed. It is found that expansion half angle has great effect on the effectiveness of vectoring primary flow with dilator using microjet actuator; if the expansion half angle is small, the wall-attached flow of micro jet plays a main role in driving the primary flow flows along dilator wall; if the expansion half angle is big enough, the coupling effect between microjet and shear layer plays the main role. With the increase of the velocity of the actuator, the controlling efficiency of microjet is expanded. Besides, dilator decreases the distance sensibility between actuator and primary flow. With the increase of primary flow velocity, the controlling efficiency of microjet is decreased.
Star Sensor Layout Design Based on PSO
Authors: Zha Micheng , Zhao Liping
Published: June 2020

Incident light, such as sunlight and atmosphere-earth light, will interfere with the viewing field of star sensor, and the accuracy and precision of star sensor will decrease. A design method based on PSO algorithm and STK software to solve layout problems efficiently is applied. The star sensor layout problem is described as the problem of finding the global optimal solution in three-dimensional space. The results show that this method can solve the problem of satellite sensor layout quickly and effectively and the method has certain engineering application value.
Effect of tungsten on creep properties of martensitic 9Cr steel
Authors: Hu F Y , Zhang S J , Shen J J
Published: June 2020

The effects of tungsten on the creep behavior and microstructure of tempered martensite 9Cr steel with different W concentrations ranging from 0–2.5 wt% were studied. The matrix consisted of tempered lath martensite structure and M23C6 located along the grain boundary or inside the grain. As the W concentration increased, the number of M23C6 increased while the particle size decreased. Also, with the increasing W concentration, the minimum creep rate and elongation decreased while the time to rupture increased. The rise in W concentration led to the refinement of M23C6, which enhanced the creep strength but reduced the creep plasticity.
Numerical study on porosity distribution in casting under micro- amplitude vibration condition
Authors: You K , Rao L , Bai X , Miao T Y
Published: June 2020

Combining with Pequet’s porosity model, this paper coupled vibration effect into the heat transfer models based on the turbulent heat transfer theory, on this basis porosity distribution of alloys under micro-amplitude vibration conditions can be analyzed. The simulated porosity results of ZL201 alloy show that appropriate vibration frequency (10Hz˜30Hz) promoted the mass feeding and capillary feeding by increasing the Dendrite Arm Spacing (SDAS) and heat transfer specific surface area of mass liquid channel, thus efficiently decreasing porosity distribution in casting. However, too high vibration intensity (40Hz˜50Hz) may deteriorate porosity distribution in casting due to insufficient feeding capacity. The vibration model provides a theoretical basis for the study on effect of mechanical vibration on casting, which is significant for the optimization of vibration parameters and porosity prevention in casting technology.
Finite element model and experimental verification of Glare laminate impact
Authors: Cui X , Zhang Z Y , Wang S
Published: June 2020

In this paper, a finite element simulation model is established for the impact of Glare laminates, and the reliability of the model is verified by experiments. Glare applies the continuum damage mechanics (CDM) model and inputs the user material subroutine VUMAT to determine the damage of the material based on the theory of CDM under plane stress state. By comparing the ultrasonic scanning experiment after impact damage with the CDM finite element simulation cloud pattern used in this paper, the constitutive relation of the fibre continuous damage model used in this paper can better simulate the damage initiation, evolution and damage of internal materials.
Numerical study on effect of micro-amplitude vibration on the grains morphology of alloys
Authors: Rao Lei , You Kai , Bai Xue , Miao Tianyu
Published: June 2020

Combining with CAFE model, this paper introduced a modified heat transfer model which interfere the effect of mechanical vibration based on turbulent heat transfer theory, on this basis the grains morphology of alloys under micro-amplitude vibration can be analyzed. Based on this model, the results of ZL201 alloys showed that vibration can promote columnar-to-equiaxed transition (CET) and grain refinement, and improve homogeneity of grains distribution. The optimum vibration frequency in current study is 40Hz. The method used in this paper provides a reference for study on the theory of vibration casting and is beneficial for parameters optimization of mechanical vibration in foundry field.
Fire resistance characteristics of steel-concrete-steel structure and reinforced concrete structure in an eight-lane dual-directional super large-span immersed tunnel
Authors: Zhengmao Cao , Liu Xiao
Published: June 2020

In order to obtain the fire resistance of Steel-Concrete-Steel structure(SCS) and reinforced concrete structure(RC) in super-large span cross section immersed tunnel, fire numerical simulation calculation was conducted to analyze the temperature field of SCS and RC in an Eight-lane Dual-Directional immersed tunnel fire by the finite element method. Three-dimensional finite element models of steel and concrete composite structure under different tunnel fire scenarios in terms of reasonable thermal parameters, material model, and correct boundary conditions was established. On this basis, analysis for the mechanical properties of the composite steel-concrete structure under the ISO-834 standard fire was conducted. The results of the study indicate that temperature of RC slab near the fire surface is grew faster than SCS slab in the immersed tunnel fire, and the temperature inside the SCS slab is lower than that of RC slab in the immersed tunnel fire. The temperature at the nearest monitoring point by the fire surface of the SCS slab is 31.3% lower than that at the same position in the RC slab, which is 41% lower in the center of SCS slab. Research result provide a reference to the theoretical studies and practical engineering of SCS extra larger span immersed tunnel fire, and provide support for the fire protection design of SCS structures in practical engineering.
Stability Test of Nanostructured Lipid Carriers-Loaded Mefenamic Acid prepared by Microemulsion Technique
Authors: Suksaeree Jirapornchai , Treelop Apinya , Veeravatanayothin Pitsacha , Maneewattanapinyo Pattwat , Monton Chaowalit
Published: June 2020

The objectives of this study were to prepare the nanostructured lipid carriers (NLCs)-loaded mefenamic acid and to study the particle size and zeta potential of the NLCs-loaded mefenamic acid after storage in refrigerator (approximately 2 – 4°C) for 7 days. The preparation method of NLCs-loaded mefenamic acid used the microemulsion technique. All compositions were vigorously mixed with vertex method to obtained the clear microemulsion solution. Tween®80 (surfactant) and 1 – butanol (co – surfactant) were mixed at the ratio of 3:2 to use as the surfactant mixture. Then, it was dispersed in cold water (approximately 2 – 4°C) at different ratio, and the droplet size was reduced by a homogenizer at 6, 000 rpm for 5 minutes and sonicator for 30 minutes to form the NLCs-loaded mefenamic acid. The prepared NLCs-loaded mefenamic acid were kept in refrigerator (approximately 2 – 4°C) for 7 days. After that, the solutions were tested the particle size and zeta potential. The particle size and zeta potential of NLCs-loaded mefenamic acid after storage were in the range of 160-310 nm and -4.00 to -19.00 mV, respectively. It was found that the F4 formula was the best to prepare the NLCs-loaded mefenamic acid. F4 formula composed of the 1%w/w mefenamic acid, 10%w/w water, 80%w/w surfactant, and 10%w/w capric triglyceride, and the dilution ratio was 1:25.
Decomposition of the Vector Field of Preferred Directions for Optimization of Five-Axis Machining
Authors: Makhanov S. S.
Published: June 2020

A new algorithm to increase the production rate of a five-axis milling machine through improving the coordinates of the to-be-milled points transformed from the workpiece to the machine coordinates is presented and analysed. The method optimizes the cutting path by following a vector field (VF) of optimal directions maximizing the material removal rate (MRR). The algorithm includes grid generation, space filling curves (SFC) and a VF decomposition using rotation invariant complex moments. The case of a radial tool path requires a special treatment called Compact Radial Zigzag (CRZ). To reduce the redundancy, the CRZ is composed of layers with a varying step between the tracks. The combination of the proposed techniques generates tool paths which produce complex shaped Stereolithography (STL) surfaces faster than the conventional methods.
Effects of Surface in the IR and Raman Spectrum of Porous Silicon Carbide
Authors: Bermeo R , Arellano L. , Trejo A , Salazar F , Calvino M. , Miranda A , Cruz-Irisson M
Published: June 2020

Porous Silicon carbide has been identified as an attractive material for its use as electrode in supercapacitors, however the theoretical investigations about its properties, specially its vibrational properties, are still scarce. In this work the effect of the Si-C surface ratio on the vibrational properties, IR and Raman spectrum of porous silicon carbide was studied using the first principles density functional perturbation theory. The porous structures were modelled by removing atoms in the [001] direction from an otherwise perfect SiC crystal using the supercell scheme. The morphology of the pores was chosen so there would be more Si or C in the pore surface. The results show that the vibrational properties, and thus the IR and Raman spectrum of the porous SiC change depending if the pore surface is either Si or C rich, having the Si-rich pores more low frequency modes due to its higher mass. Also, the effects of phonon confinement are lessened by the effect of surface passivation, thus indicating that the surface plays an important role in the IR and Raman characterization of these structures.
Visible and Infrared Photoluminescence in Hexagonal Silicon Carbide by Direct Femtosecond Laser Writing
Authors: Castelletto Stefania , Johnson Brett C , Boretti Alberto
Published: June 2020

Optically active color centers in silicon carbide have attracted considerable attention in the past few years as candidates for quantum technologies such as single-photon sources, nanomagnetic resonance imaging, and spintronic devices. Control over defect position and their placement at the desired location within a chip, necessary to integrate them within optical and electronic devices, is still a challenge. Recently, laser writing emerged as a new tool to generate vacancies in crystals as a starting point for the formation of color centers. In this work, a laser writing method has been used to produce color centers in 4H and 6H bulk silicon carbide by using a femtosecond laser. An array of color centers was fabricated by different pulse laser energies in sites of square grids at varying depths (from the surface to 10 µm below the surface). We optically characterized the fabricated color centers using confocal imaging, photoluminescence, and Raman spectroscopy. We show that the technique can produce specifically vacancy color centers with a relevant emission in the visible (peak around 700 nm) and near-infrared (peak at 900 nm) with the latter identified as the silicon-vacancy. This method can be adapted to engineer color centers in silicon carbide at different depths in the material, for the above-mentioned applications, in addition to the fabrication of light-emitting diodes.