Sweet cherries from farm to table: A review

In order to enable long-distance transportation and ensure that the fruit presents the requisite quality on arrival at markets, the cherry industry for direct consumption needs to prolong post-harvest shelf life. Sweet cherries are highly perishable, non-climacteric fruits with shelf life of 7–14 days in cold storage. Their shelf life is shortened by loss of firmness, color and flavor, stem discoloration, desiccation and mould growth. Various factors such as harvest time, proper handling and cooling practices and above all packaging, greatly influence the shelf life of cherries. One of the areas of research that has shown promise, and had success, is modified atmosphere packaging (MAP). It is one of the fastest growing packaging technologies and has many advantages for different food products. Properly designed modified atmosphere packs can be exploited to lower respiration rates and thus ripening of fruits which results in least changes in physiochemical parameters of sweet cherries during postharvest storage. This paper intended to review a broad spectrum of studies dealt with the use of MAP for preservation of sweet cherries cultivars with an interest for future research work.     

Primary explosives: electrostatic discharge initiation, additive effect and its relation to thermal and explosive characteristics

All explosives, under all conditions must be considered vulnerable to generation, accumulation and discharge of static charge. The low energy static hazards of the order as low as 2-3 mJ need to be guarded against in case of highly sensitive compounds namely primary explosives. The hazard is normally associated with manufacturing and filling operations due to discharge of static charge accumulated on a person supplying energy up to 20 mJ. To reduce the risk associated with static initiation hazard in the processing and handling of the explosives, the electrostatic sensitivity tests can provide an important input regarding electrostatic hazards. This paper presents electrostatic sensitivity data in terms of zero ignition probability data (E(SE0)) of some of the initiatory explosives such as nickel/cobalt hydrazinium nitrate, silver azide, lead azide and mercury salt of 5-nitro tetrazole. Similar data has also been presented for samples coated with polyvinyl pyrrolidone to study its effect on electrostatic sensitivity. The electrostatic spark sensitivity of some conventional and novel made to explain the increased spark sensitivity behavior on the basis of the possible primary explosives has been studied. The electrostatic spark sensitivity of primary explosives decreased in the order of AgN3 = NHN > PbN6 > MNT > CoHN > BNCP. A possible correlation of spark energy with approximation and assumption has been drawn with thermal, detonation and mechanical properties. The polyvinyl pyrrolidone coated samples followed the same order but interestingly with increased spark sensitivity. An attempt has been reasoning of dielectric nature of the materials or exothermic effects of decomposition products of PVP. The present work also reports the electrostatic spark sensitivity of cap compositions.     

Silver nanoparticles: Large scale solvothermal synthesis and optical properties

Silver nanoparticles have been successfully synthesized by a simple and modified solvothermal method at large scale using ethanol as the refluxing solvent and NaBH₄ as reducing agent. The nanopowder was investigated by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), dynamic light scattering (DLS), UV-visible and BET surface area studies. XRD studies reveal the monophasic nature of these highly crystalline silver nanoparticles. Transmission electron microscopic studies show the monodisperse and highly uniform nanoparticles of silver of the particle size of 5 nm, however, the size is found to be 7 nm using dynamic light scattering which is in good agreement with the TEM and X-ray line broadening studies. The surface area was found to be 34.5 m²/g. UV-visible studies show the absorption band at ∼425 nm due to surface plasmon resonance. The percentage yield of silver nanoparticles was found to be as high as 98.5%.     

Conductive polymer composite materials and their utility in electromagnetic shielding applications

Commercial electronic devices require shielding solutions that ensure electromagnetic compatibility (EMC) while accounting for effects of specific enclosure structural features such as seams, vents, and port dimensions. In practice, suitable EMC materials combine with the device operating characteristics to determine an overall shielding response. To optimally couple plastic design practices with EMC requirements, both polymer materials science and electrical engineering concepts, must be considered. Use of extrinsically conductive polymer (ECP) formulations for electronic applications has advantages in that they can be directly molded to a desired shape and serve to provide the necessary shielding while also meeting mechanical integrity requirements. Shielding and mechanical performance can be varied via filler loading or altered through wall thickness changes to satisfy demands associated with a particular device. Injection‐moldable ECP polycarbonate‐based formulations can attain average shielding effectiveness (SE) levels of ～50–60 dB through 2 GHz at 2‐mm thickness as measured using ASTM D 4935 procedures. These values vary with thickness, and SE improvements of ～10–20 dB are observed when increasing from 1 to 2 mm. Additionally, resultant mechanical properties of shielding composites are strong functions of overall fiber content. These interrelated material and shielding characteristics, which form the basis for filled conductive polymer use within practical enclosure shielding designs, are described. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Biofiltration control of pulping odors – hydrogen sulfide: performance,macrokinetics and coexistence effects of organo‐sulfur species

The work reported here describes the aerobic biodegradation of reduced sulfur compound mixtures in air streams by biofilters. Rates of removal of hydrogen sulfide as a sole substrate and in the presence of organo‐sulfur compounds were determined to see if there were any inhibitory effects of the organo‐sulfur compounds on the rate of hydrogen sulfide removal. Experiments were conducted in three bench‐scale biofilters packed with the mixtures of compost/perlite (4:1), hog fuel/ perlite (4:1), and compost/hog fuel/perlite (2:2:1), respectively. Hydrogen sulfide, the predominant odorous gas produced from kraft pulping processes, was used as the main pollutant (substrate). Other organo‐sulfur species (dimethyl sulfide and dimethyl disulfide), also emitted from kraft pulp mills, were used as competing (secondary) substrates in the waste gas stream. To describe rates of removal a Michaelis–Menten type kinetic equation was modified to incorporate the plug flow behavior of biofilters, and used in evaluating the pseudo‐kinetic parameters, V_max (the maximum removal rate) and K_m (the half saturation concentration), for hydrogen sulfide biodegradation, and the type of macrokinetic competition between hydrogen sulfide and the organo‐sulfur compounds. No significant differences in V _max for the three biofilters were observed. The V _max ranged between 136 and 147 g m⁻³ h ⁻¹, while the K_m varied from 44 to 59 ppmv for the three biofilters. Hydrogen sulfide elimination capacity was not affected by the presence of any of the organo‐sulfur species in all of the three biofilters, confirming earlier results that hydrogen sulfide removal in biofilters is independent of the presence of organo‐sulfur compounds mainly because of its easy biodegradability. © 1999 Society of Chemical Industry     

Improving hydrocarbons production via catalytic co-pyrolysis of torrefied-biomass with plastics and dual catalytic pyrolysis

To increase the low yield and selectivity of aromatic hydrocarbons during the biomass pyrolysis process, we torrefied the biomass and then co-pyrolyzing with plastics such as high-density polyethylene (HDPE), polystyrene (PS), ethylene-vinyl acetate (EVA) and polypropylene (PP) and also single and dual catalyst layouts were investigated by Py-GC/MS. The results showed that non-catalytic fast pyrolysis (CFP) of raw bagasse (RBG) generated no aromatics. After torrefaction non-CFP of torrefied bagasse (TBG) generated low aromatic yield. Indicating that torrefaction would enhance the proportion of aromatics during the pyrolysis process. The CFP of TBG_200℃ and TBG_240℃ over ZSM-5 produced the total aromatic yield of 1.96 and 1.88 times higher, respectively, compared to non-CFP of TBG. Furthermore, the addition of plastic could increase H/Ceff ratio of the mixture, consequently, increase the yield of aromatic compounds. Among the various torrefied-bagasse/plastic mixtures, the CFP of TBG/EVA (7:3 ratio) mixture generated the highest the total aromatic yield of 7.7 times more than the CFP of TBG alone. The dual catalyst layout could enhance the yield of aromatics hydrocarbons. The dual-catalytic co-pyrolysis of TBG_200℃/plastic (1:1) ratio over USY (ultra-stable Y zeolite)/ZSM-5, improved the total aromatics yield by 4.33 times more than the catalytic pyrolysis of TBG_200oC alone over ZSM-5 catalyst. The above results showed that the yield and selectivities of light aromatic hydrocarbons can be improved via catalytic co-pyrolysis and dual catalytic co-pyrolysis of torrefied-biomass with plastics.     

Effect of ethylenediaminetetraacetic acid (di sodium salt) and aquasoft 330 on crystal growth and morphology of calcium oxalate

Calcium oxalate was synthesized from calcium chloride solution using oxalic acid in the presence of di sodium salt of ethylenediaminetetraacetic acid (EDTA) and commercially available1-hydroxyethylidene-1,1-diphosphonic acid (HEDP), aquasoft having chelating value 330 (AQ 330). The experiments were carried out at three different temperatures 60, 80 and 100 °C. The samples were characterized using scanning electron microscope (SEM), powder X-ray diffraction analysis (XRD) and Fourier transform infrared spectroscopy (FTIR) techniques. The morphological studies reveal that the tendency for agglomeration increases with increase in temperature. Interpretation of XRD pattern confirmed that whewellite with monoclinic structured is the most favored structure in the presence of EDTA where calcium oxalate hydrate having orthorhombic structure is most favored structure in the presence of AQ 330.     

Degradation Kinetics of Lycopene and Visual Color in Tomato Peel Isolated from Pomace

Kinetics of lycopene and visual color degradation of tomato peel was studied at selected temperatures (50–100°C). Models based on lycopene and Hunter (a?×?b) values of fractional conversion were applied to determine the kinetic parameters. The degradation of lycopene and Hunter color values adequately followed first order reaction model with R²?>?0.97. The temperature dependence of the rate constants was adequately modeled by the Arrhenius equation. The activation energies of lycopene and color parameters were 18.27 and 29.07 kJ/mol, respectively, indicating greater temperature sensitivity of visual color parameters. Correlation of lycopene content and Hunter (a?×?b) values showed that they can be used interchangeably with good accuracy.