Characteristics of corn starch-based edible coating enriched with curry leaf extract on quality of the strawberry (Fragaria x ananassa Duch.)

Strawberry is one of the most popular tropical fruits in Indonesia. The fruit has a concise shelf life and quickly deterioration after harvesting due to mechanical injury, physiological disorders, water loss, fungal growth, and high respiration rates. Postharvest technology is one technique that can maintain fruit quality and extend shelf life, one of which is a coating technique called edible coating. The edible coating layer of corn starch with the addition of curry leaf extract has antibacterial activity that can inhibit the growth rate of microorganisms. This study aimed to determine the characteristics of the edible coating solution produced from corn starch with the addition of curry leaf extract to produce the best edible coating layer. This study used a factorial completely randomized design experimental method, which consisted of treatment with curry leaf extract concentration (8%, 10%, and 12%) and dipping time (4, 5, and 6 minutes) with three repetitions. The result showed a significant delay in weight loss and total dissolved solids in strawberries compared to the uncoated control strawberries. In addition, the edible coatings had positive results in organoleptic based on panelists’ acceptance of color, aroma, taste, texture, and overall. These findings suggest that using 8% curry leaf extract with 4 minutes dipping time could be favorable to extend the shelf-life and maintain the quality of strawberry fruit.

Investigation into Effect of Natural Shellac on the Bonding Strength of Magnesium Substituted Hydroxyapatite Coatings Developed on Ti6Al4V Substrates

The bioactive and biocompatible properties of hydroxyapatite (HA) promote the osseointegration process. To enhance other bio-functions of HA such as improving the antibacterial property of the implant, increasing the rate of cell proliferation, or improving tissue generation capability, HA is substituted with many elements such as Zn, Cl, Ba, Fe, Cu, Ag, Sr, F, Na, etc. This study reports development of Magnesium substituted HA (Mg-HA) coatings on Ti6Al4V substrates using the dip coating technique. To improve the adhesion and stability of the coating, an intermediate layer of shellac was applied between the coating and Ti6Al4V substrate. The dip coating process parameters were optimized using the Taguchi technique and it was found that dipping time of 35 s and 13% w/w of shellac concentration provided the maximum bonding strength of 12.5 MPa. The biocompatibility, dissolution, and corrosion study of the developed coating using the optimal parameters obtained were carried out in this study. An improvement in cell growth and cell proliferation was observed in the extract medium prepared from coated substrates. Release of Ca, P and Mg ions from the surface of the coated substrate into the simulated body fluid (SBF) was found to be almost constant which shows the stability of the thin film coating formed. The Mg-HA coated substrate also exhibited better corrosion resistance than the uncoated substrate.

DEVELOPMENT OF FRESH AND MINIMALLY PROCESSED BANANA INFLORESCENCE

Banana inflorescence though a high valued vegetable, but its difficulty in extraction of flowers for cooking, restricts its consumption and popularity. Therefore, in order to get a solution from this problematic condition the experiment was conducted with an aim to develop banana inflorescence which would be fresh as well as minimally processed so they can be used instantly. In the present experiment ‘Kanthali’ variety for banana inflorescence was used. The bracts were separated and banana flowers were carefully removed and thereafter they were treated with various chemicals like calcium chloride, citric acid, calcium hypochlorite and even their combinations were also used. The dipping time of the banana inflorescence in the treatments was of around 10 minutes, then after keeping the treated materials under a fan in the laboratory for few minutes they were prepacked and storage was carried in refrigerated condition of 7+20 C temperature and 80-85% relative humidity. The treatments were replicated 3 times and observations for different attributes were carried at different days of storage. From the experiment it was concluded that banana inflorescence treated with combination of calcium hypochlorite, calcium chloride and citric acid was found most superior in retaining various physical and chemical properties and was with least microbial damage throughout the storage period.

Effect of coating parameters on microstructure, corrosion behavior, hardness and formability of hot-dip Galfan and galvanized coatings

In the current study, zinc–aluminum (Galfan) and zinc (galvanized) coatings were coated on steel sheets using the hot-dip technique. The effect of process parameters on the microstructure, corrosion behavior, hardness, and formability of the coatings was assessed. The results demonstrated that both the corrosion area and corrosion rate of the galvanized coatings were reduced by increasing the immersion time. In contrast, the process temperature did not affect the corrosion behavior. Furthermore, by prolonging the dipping time, the hardness of the coatings decreased. The Galfan coatings showed higher formability and the superiority of mechanical and corrosion properties of Galfan coatings over conventional galvanized coatings was indicated.

EFFECT OF HOT DIPPING ALUMINIZING ON THE TOUGHNESS OF LOW CARBON STEEL

Steel that has been aluminized said as hot dipping aluminizing has better protection against corrosion and can protect against temperatures as high as 800°C. In hot dipping aluminizing, Steel is immersed into a molten aluminium for certain dipping time. The research aims to know the effect of preheating and dipping time on the toughness of low carbon steel. The method research was started by cutting the low carbon steel plate, according to ASTM E23 (Charpy test sample) into 16 pieces samples. Then the samples were grouped into four groups. Group-1 was initial samples. The Group-2 was directly immersed into molten aluminum 700 0C, for dipping time 5 minutes. The Group-3 was preheated at 700 oC for 30 minutes and then to be aluminized (700 oC) for dipping time 5 minutes. The Group-4 was preheated at 700 oC for 30 minutes and then to be aluminized (700 oC) for dipping time 10 minutes. Finally, all groups were tested by the Charpy test at room temperature. The results show that the aluminizing increases the toughness of low carbon steel from 228.125 KJ/m2 to 312.5 KJ/m2. The preheating process before aluminizing increases sharply the toughness of low carbon steel from 228.125 KJ/m2 to 512.5 KJ/m2. The increasing dipping time from 5-minute to 10-minute increase gradually the toughness from 512.5 KJ/m2 to 556.25 KJ/m2.

Pebax 1657 Nanocomposite Membranes Incorporated with Nanoadsorbent Derived from Oil Palm Frond for CO2/CH4 Separation

Membrane technology has attracted significant attention from the researchers, especially in gas separation process due to their simple process design and low capital cost compared to conventional techniques. In this work, oil palm frond (OPF) waste was used as nanoadsorbent embodied in polyether block amide (Pebax 1657) nanocomposite membrane to improve the CO2/CH4 separation. The effectiveness of the nanoadsorbent derived from OPF was evaluated by varying the nanoadsorbent concentration (2–8 wt %) and controlling the Pebax 1657 concentration (5 wt %), dipping time (5 s), and number of sequential coatings (3 layers). The pore characteristics of the nanoadsorbent was analyzed using Brunauer–Emmett–Teller (BET) analysis. The morphology and the existence of active groups in the newly synthesized nanoadsorbent and nanocomposite membranes were investigated using field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy (FTIR), respectively. The single gas permeation process was carried out at constant pressure (2 bar) and room temperature (25 ± 5 °C). The optimum condition with 5 wt % nanoadsorbent made the nanocomposite membrane exceeded the trade-off limit of the Robeson plot with a CO2 permeability and CO2/CH4 selectivity of 1475.09 Barrer and 40.48, respectively.

Tuning the Photo-Luminescence Properties of WO3 Layers by the Adjustment of Layer Formation Conditions

In this research we have applied sol-gel synthesis for the deposition of tungsten (VI) oxide (WO3) layers using two different reductants (ethanol and propanol) and applying different dipping times. WO3 samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier Transform Infrared spectroscopy (FTIR), photoluminescence (PL) and time-resolved photoluminescence decay methods. Photoelectrochemical (PEC) behaviour of synthesized coatings was investigated using cyclic voltammetry in the dark and under illumination. Formation of different structures in differently prepared samples was revealed and significant differences in the PL spectra and PEC performance of the samples were observed. The results showed that reductant used in the synthesis and dipping time strongly influenced photo-electrochemical properties of the coatings. Correlation between the morphology, PL and PEC behaviour has been explained.

Optimal Hot-Dipped Tinning Process Routine for the Fabrication of Solderable Sn Coatings on Circuit Lead Frames

Previous studies merely focus on the hot dipping properties of lead frame materials used in electronic industry. Yet, the environmentally friendly and cost-efficient traits of hot-dipped tinning process make it a possible promising surface modification technique compared with electroplating. As a result, the optimal hot-dipped tinning process routine is proposed in this paper. The hot-dipped tinning process of four different types of copper foils (C11000, C19400, C19210, and C70250), pretreatment parameters, mechanical properties of Cu substrates, thickness of IMC (intermetallic compound) layers and coatings, and microstructure of coatings were investigated to determine the copper substrate suitable for hot-dipped tinning and the optimized tinning procedures. The results indicate that a proper increase in alloying elements (e.g., Cu-Fe-P series alloys) towards Cu substrate leads to a decrease in hot dipping performance. The proper process routine is determined as alkaline cleaning→water scrubbing→accelerant solvent dipping→drying→hot-dipped tinning→cooling. The appropriate dipping temperature range is 260 to 280 °C, which assists to maintain acceptable micro hardness (i.e., maintaining at least 95% of the original hardness). The optimal dipping time should be set as 6–10 s. The proposed hot-dipped tinning process routine may present a guideline for the fabrication of tin coating in electronic industry.