Preservation of fruits and vegetables using solar drier: a comparative study of natural and solar drying, III; chemical analysis and sensory evaluation data of the dried samples (grapes, figs, tomatoes and onions)

In spite of the detailed studies which have proved the superiority of the quality attributes for solar dried fruits and vegetable over that of naturally dried [1, 2, 3, 4 and 5], we have chosen in our investigation some parameters to be used as a guide to test the changes occurring for some nutrients like sugars. Another indicator has been used which was the percent ash to test the extent of contamination with sand from the surroundings. Consequently we can compare the properties and qualities of natural and solar dried fruits and vegetables to arrive at the preferred drying method.From the project results obtained for the dried fruits and vegetables using natural and solar drying, we can conclude that the mixed and indirect modes of drying were more effective than natural drying, since the final moisture contents for grapes were 12.5, 20.05 and 68.45%, respectively. The figs moisture was reduced to 23.5% using mixed mode drying and 46.9% in case of natural drying for the same period. No significant difference was noted in the case of tomatoes, while there was little significant difference between the two drying methods for onions, but the drying was higher for slices than lobes.There was a highly significant difference for percent ash between the solar dried grapes and naturally dried samples (2.95 and 12.1%, respectively).In sugar determination, the solar drying was found to alter the sugars more than natural drying. This is not surprising because the temperature inside the drying chamber was far higher (80.5°C).This study included also the sensory evaluation of the quality attributes (color, flavor and texture) of the dried samples. The fruits were presented to untrained panelists (consisting of engineers, employees, Ph.D. holders and workers from the Center for Solar Studies) who were asked to evaluate the fruits by scoring the attributes with grades ranged from 2 to 12, where 2=weakly accepted and 12=excellent quality.The data represent the relative frequency distribution ×100 (for color, flavor and texture) reported by the panelists using a hedonic scale from (1–12). Lower scores indicate poor quality (unacceptable) while higher scores indicate much better quality or highly acceptable.These data clearly indicate that the solar drying technique is much better from the sensory quality viewpoint when compared with the natural sun drying technique. Such conclusions are completely true for all samples except tomatoes, and both direct methods of drying as well as mixed mode approach of solar drying. Since negative findings were reported using the indirect approach.     

Effect of nano-sized PbO on the transport critical current density of (Bi1.6Pb0.4Sr2Ca2Cu3O10)/Ag tapes

The effect of nano-sized PbO (10–30 nm) addition on the transport critical current density, J_c of (Bi_1.6Pb_0.4)Sr₂Ca₂Cu₃O₁₀ (PbO)_x (x=0–0.15 wt%) was investigated. J_c of PbO added pellet samples showed the maximal value at x=0.05 wt%. Using this result, Ag-sheathed (Bi_1.6Pb_0.4)Sr₂Ca₂Cu₃O₁₀ (PbO)_x/Ag tapes (x=0 and 0.05 wt %) were fabricated by the powder-in-tube (PIT) method. The tapes were sintered for 50 h and 100 h at 845 °C. The temperature dependence of J_c for the non-added and PbO added tapes in applied field was investigated. J_c of the non-added tapes was 4510 A/cm² at 40 K and 949 A/cm² at 77 K. J_c of (Bi_1.6Pb_0.4)Sr₂Ca₂Cu₃O₁₀ (PbO)_0.05/Ag tape sintered for 100 h was 26,800 A/cm² at 40 K and 10,700 A/cm² at 40 K, which was higher than the tapes sintered for 50 h (8590 A/cm² at 40 K and 1880 A/cm² at 77 K). Nano-sized PbO added tapes sintered for 100 h showed a higher J_c (more than 10 times) under magnetic field (0–0.75 T) compared with the non-added tape. A combined effect of enhanced flux pinning and improved microstructure led to the significant increase in J_c of the nano-sized PbO added tapes.     

High-Frequency Fatigue Behavior of Woven-Fiber-Fabric-Reinforced Polymer-Derived Ceramic-Matrix Composites

The monotonic and high-frequency (100 Hz) fatigue behavior of two Nicalon-fabric-reinforced SiCON matrix composites was investigated at room temperature. The matrix composition was varied by the addition of BN and SiC particulate fillers, to contain shrinkage from processing by polymer infiltration and pyrolysis (PIP). The composites had strong fiber/matrix bonding, which resulted in substantially less frictional heating than observed with weakly bonded composites. Both composites exhibited fatigue runout at 10⁷ cycles at ∼80% of the monotonic strength. Comparison with existing fatigue data in the literature (for the same composites) at 1 Hz shows no change in fatigue life; i.e., no frequency effect was observed. Most of the stiffness reduction in the composites occurred in the first fatigue cycle, whereas subsequent decreases in moduli were attributed to limited fiber cracking. The major driving force for failure was the localized debonding of transverse and longitudinal plies at the crossover points in the fabric, which, when linked, resulted in interlaminar damage and failure in the composite.     

Taxonomic investigation of selected rust fungi using scanning electron microscopy from Khyber Pakhtunkhwa,Pakistan

Rusts comprises the largest natural group of plant pathogens including approximately 8% of all described Fungi. Rust fungi are extremely plant pathogens responsible for great losses to agriculture productivity. Rust species belong to several genera among which more than half are Puccinia species. In Pakistan, rust causes severe damage to agriculture crops. Current study was carried out to identify and characterize different rust species common in the research area through microscopy and Scanning electron microscopy (SEM) in Khyber Pakhtunkhwa, Pakistan. Morpho-anatomical investigation of each collected rust species was carried out using different standard protocols. The dimensions of spores were measured and snapped under a stereomicroscope. SEM was used to examine the shape, size, and ornamentation of the spores of each rust fungus. Results revealed documentation of seven rust fungi, that is, Melampsora euphorbiae, Phragmidium barclayi, Puccinia nepalensis, P. exhausta, P. menthae, Uromyces capitatus, and Uromyces decorates belong to four different genera, were recorded. SEM revealed that spermogonia and Aecia were missing in most of the rust fungus studied. Uredinia was found in a scattered, irregular, lengthy, and epidermis-enclosed form. Urediniospores were found to be ovulating, elongated, echinulate, globose to sub-globose, ellipsoid to ovoid, and globose to sub-globose. Telia was found as sub-epidermal, amphigenous, dispersed, minute, and spherical cells. Teliospores ranged in form from cylindrical to oblong. The germ pores were detected in both apical (top cell) and basal (bottom cell) idiosyncratic and pedicel-attached cells. The techniques used in the current investigation will aid mycologists in rust identification and microscopic characterization.     

Design,Fabrication and Experimentation of a Deep Drawing Machine

This paper presents the work implemented in designing, fabricating and operating a model of a cheap hydraulic DDM （deep drawing machine）, which is currently utilized in the manufacturing processes lab in the IED （Industrial Engineering Department） at An-Najah National University. The machine is used to conduct different experiments related to the deep drawing process. This work was implemented in three stages： the first was the design stage, in which all design calculations of the DDM elements were completed based on the specifications of the product （cup） to be drawn; the second was the construction stage, in which the DDM elements were fabricated and assembled at the engineering workshops of the university; the last was the operating and experimentation stage, in which the DDM was tested by conducting different experiments. The experience gained from designing and constructing such a mechanical lab equipment was found to be successful in terms of obtaining practical results that agree with those available in literature, cost-effective relative to the cost of a similar purchased equipment, as well as enhancing students＇ abilities in understanding the deep drawing process in particular and machine elements design concepts in general.     

Finite element modeling and simulation of proposed design magneto-rheological valve

Magneto-rheological (MR) valve is one of the devices generally used to control the speed of Hydraulic actuator of MR fluid. The performance of valve depends on the magnetic circuit design. Present study deals with a new design of MR valve. A mathematical model for the MR valve is developed and the simulation is carried out to evaluate the newly developed MR valve. The design of the magnetic circuit is accomplished by magnetic finite element software such as Finite Element Method Magnetic (FEMMR). The model dimensions of MR valve, material properties are taken into account. The results of analysis are presented in terms of magnetic strength H and magnetic flux density B. The simulation results based on the proposed model indicate that the efficiency of the proposed MR valve is superior to two other types of MR valves, under the same magnetic flux density. As a conclusion, the new valve design has improved the efficiency of MR valve significantly.     

Inducement of Itinerant Electron Transport in Charge-Ordered Pr<Subscript>0.6</Subscript>Ca<Subscript>0.4</Subscript>MnO<Subscript>3</Subscript> by Ba Doping

The effects of Ba ²⁺ doping on the electrical and magnetic properties of charge-ordered Pr_0.6Ca_0.4MnO₃ were investigated through electrical resistivity and AC susceptibility measurements. X-ray diffraction data analysis showed an increase in unit cell volume with increasing Ba ²⁺ content indicating the possibility of substituting Ba ²⁺ for the Ca-site. Electrical resistivity measurements showed insulating behavior and a resistivity anomaly at around 220 K. This anomaly is attributed to the existence of charge ordering transition temperature, \(T^{\mathrm {R}}_{\text {CO}}\) for the x = 0 sample. The Ba-substituted samples exhibited metallic to insulator transition (MI) behavior, with transition temperature, T _MI, increasing from ～98 K (x = 0.1) to ～122 K (x = 0.3). AC susceptibility measurements showed ferromagnetic to paramagnetic (FM-PM) transition for Ba-substituted samples with FM-PM transition temperature, T _c, increasing from ～121 K (x = 0.1) to ～170 K (x = 0.3), while for x = 0, an antiferromagnetic to paramagnetic transition behavior with transition temperature, T _N, ～170 K was observed. In addition, inverse susceptibility versus T plot showed a deviation from the Curie–Weiss behavior above T _c, indicating the existence of the Griffiths phase with deviation temperature, T _G, increasing from 160 K (x = 0.1) to 206 K (x = 0.3). Magnetoresistance, MR, behavior indicates intrinsic MR mechanism for x = 0.1 which changed to extrinsic MR for x > 0.2 as a result of Ba substitution. The weakening of charge ordering and inducement of ferromagnetic metallic (FMM) state as well as increase in both T _c and T _MI are suggested to be related to the increase of tolerance factor, τ, and increase of e _g ?electron bandwidth as average ionic radius at A-site, <r _A> increased with Ba substitution. The substitution may have reduced MnO₆ octahedral distortion and changed the Mn–O–Mn angle which, in turn, promotes itinerancy of charge carrier and enhanced double exchange mechanism. On the other hand, increase in A-site disorder, which is indicated by the increase in σ ² is suggested to be responsible for the widening of the difference between T _c and T _MI.     

Flexural behavior of stratified reinforced concrete: construction,testing, analysis,and design

Stratified concrete poses a promising alternative for construction. Its fresh and hardened properties have been studied at the material level; however, structural behavior in steel reinforced specimens has not been studied. This paper focuses on the flexural behavior of eight stratified reinforced concrete (SRC) specimens representing slices from a slab or non-bearing wall. Specimens with two stratified concrete designs and three steel ratios were tested and compared to estimates from a fiber element numerical model and rectangular stress-block design methods from ACI 318 and Eurocode 2. The results suggest that SRC has similar damage modes as ordinary reinforced concrete (ORC). The fiber element model accurately estimated the measured behavior, while ACI 318 and Eurocode 2 differed from the experimental results by <25%. These prediction accuracies are similar to those for ORC. Therefore, the flexural design of SRC can be done using both fiber element and rectangular stress-block approaches.     

Eco‐friendly synthesis of silver nanoparticles and its larvicidal property against fourth instar larvae of Aedes aegypti

In this study, larvicidal activity of silver nanoparticles (AgNPs) synthesised using apple extract against fourth instar larvae of Aedes aegypti was determined. As a result, the AgNPs showed moderate larvicidal effects against Ae. aegypti larvae (LC₅₀  = 15.76 ppm and LC₉₀  = 27.7 ppm). In addition, comparison of larvicidal activity performance of AgNPs at high concentration prepared using two different methods showed that Ae. aegypti larvae was fully eliminated within the duration of 2.5 h. From X‐ray diffraction, the AgNP crystallites were found to exhibit face centred cubic structure. The average size of these AgNPs as estimated by particle size distribution was in the range of 50–120 nm. The absorption maxima of the synthesised Ag showed characteristic Ag surface plasmon resonance peak. This green synthesis provides an economic, eco‐friendly and clean synthesis route to Ag.Inspec keywords: silver, nanofabrication, X‐ray diffraction, zoology, particle size, nanoparticles, biomedical materials, nanomedicineOther keywords: time 2.5 h, size 50 nm to 120 nm, silver nanoparticle, larvicidal property, instar larvae, Aedes aegypti, larvicidal effect, larvicidal activity performance, X‐ray diffraction, nanoparticle particle size distribution, absorption maxima, silver surface plasmon resonance peak