Bio-based composite as phase change material including spent coffee grounds and beeswax paraffin

Souissi Moez,Trigui Abdelwaheb,Jedidi Ilyes,Loukil Mohamed Sahbi,Abdelmouleh Makki 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.9

New types of bio-composite phase change materials (BCPCM) with improved thermal properties were made from spent ground coffee powder (C), beeswax (W) and low density polyethylene (LDPE). Beeswax is a relatively accessible phase change material of organic origin, with a significantly lower unit price compared to conventional phase change materials (PCM). The observations by SEM and FTIR spectroscopy showed that the BCPCMs were physically combined. Through these techniques, it was discovered that ground coffee was effectively impregnated with natural wax and LDPE. According to the thermal gravimetric analysis (TGA), the thermal stability of BCPCM was improved, due to the use of waste coffee grounds, in the working temperature range. The biocomposite possesses excellent performance as characterized by 136.9 J/g (W70C10PE20)>, 127.31 J/g (W70C20PE10)>, 126.95 J/g (W70C30)>, 121.08 J/g (W70PE30) of latent heat storage and tends to decrease the supercooling degree as compared with pure beeswax during melting/solidification process. By adding LDPE to the PCM, the melting time is reduced, demonstrating an improvement in thermal energy storage (TES) reaction time to the demand. The experimental results showed that the fraction of oils (12%) in spent ground coffee powder can participate in the improvement of the thermal properties of BCPMC. The use of biocompatible PCM by-products is suitable for applications in the field of heat storage because it is affordable and environmentally beneficial.

Bicomponent Polyesters Filaments with High Performances:Study of Their Stability before and after Dyeing with Low, Medium, and High Energy Disperse Dyes

Marwa Souissi,Ramzi Khiari,Mounir Zaag,Nizar Meksi,Hatem Dhaouadi 한국섬유공학회 2022 Fibers and polymers Vol.23 No.10

Bicomponent polyesters filaments are increasingly used in the textile fields due to their technical and highperformances (mechanical, physical, and chemical properties) comparing to conventional polyethylene terephthalate andElasthaneTM thermoplastic polyether polyurethane used in denim fabrics. The purpose of this work is to evaluate the stabilityof the mechanical and physical properties of bicomponent filaments before and after dyeing with three disperse dyes havingdifferent molecular weights (low, medium, and high). Bicomponent filaments composed of two filaments extruded side byside with two unequal proportions 60 % polyethylene terephthalate (PET) and 40 % polytrimethylene terephthalate (PTT) areused in this study. A full factorial experimental design was established to analyze the dyeing parameters effect (temperatureand pH value of dye bath) and optimize the color strength (K/S) while maintaining the stability of the mechanical andphysical properties of bicomponent filaments. After dyeing, these properties were evaluated and their stability was provedusing several analysis techniques such as SEM, DSC, and XRD.

High photocatalytic efficiency and stability of chromium-indium codoped ZnO thin films under sunlight irradiation for water purification development purposes

Refka Mimouni,Adel Souissi,Ali Madouri,Karem Boubaker,Mosbah Amlouk 한국물리학회 2017 Current Applied Physics Vol.17 No.8

In this work, we aimed an effective low-cost system for water purification from Methylene Blue using the photocatalytic performance of (Cr,In) codoped ZnO sprayed thin films under sunlight irradiation. XRD analysis demonstrate that the samples crystallized in würtzite ZnO phase, with a privileged orientation of crystallites towards (002) direction parallel to c-axis. The obtained images of AFM and SEM micrographs showed the enhancement of the roughness of ZnO films by codoping. In addition, the optical investigations indicated that the band gap values of (Cr,In) codoped ZnO thin films decreases from 3.3 eV to 3.1 eV in terms of (Cr, In) contents, whence, more solar energy can be exploited for photocatalytic reactions. Likewise, from PL study, the decrease of UV intensity peak by codoping points out the recombination inhibition in ZnO thin films. Also, the presence of defects demonstrated by visible emission has an important role in photocatalysis because on the surface of defects, surface redox reactions are taking place. So, they act as active sites of (Cr,In) codoped ZnO photocatalyst. Moreover, the effect of hydroxide OH radicals and the superoxide anion radicals (O2-) in photocatalytic mechanism for Methylene Blue degradation was discussed. Furthermore, (Cr,In) codoped ZnO thin films showed an excellent photodegradation efficiency under sunlight irradiation and present high recycling performance even after three re-use cycles.

Protein Hydrolysates from Bluefin Tuna (Thunnus thynnus) Heads as Influenced by the Extent of Enzymatic Hydrolysis

Ali Bougatef,Rafik Balti,Anissa Haddar,Kemel Jellouli,Nabil Souissi,Moncef Nasri 한국생물공학회 2012 Biotechnology and Bioprocess Engineering Vol.17 No.4

Functional properties and antioxidant activities of protein hydrolysates from tuna (Thunnus thynnus) heads (THPHs), with different degrees of hydrolysis, obtained by treatment with Bacillus mojavensis A21 alkaline proteases and Alcalase, were investigated. Protein content of all freeze-dried THPHs ranged from 73.74 ± 0.5 to 78.56 ±1.2%. The THPHs had excellent solubility, compared to untreated tuna head proteins and possessed interfacial properties, which were governed by their concentrations. Similarly, at a degree of hydrolysis (DH) of 12 and 15%,> 90% nitrogen solubility was observed at all experimental pH values tested. The emulsifying activity index (EAI) and emulsion stability index (ESI) of both hydrolysates at different DHs decreased (p < 0.05) with increasing DH. At low DH (5%), hydrolysates exhibited strong emulsifying properties. All THPHs produced by the A21 proteases generally showed higher antioxidative activity than that of the Alcalase protein hydrolysates. The highest DPPH radical-scavenging activity (78 ± 2.1% at 3 mg/mL) was obtained with a DH of 15%. The IC50 value for the β-carotene bleaching assay was 0.5 ± 0.03 mg/mL. Alcalase (DH = 12%) and A21 (DH = 15%) protein hydrolysates contained glutamic acid/glutamine and arginine as the major amino acids, followed by lysine, aspartic acid/asparagine, histidine, valine, phenylalanine, and leucine. In addition, the THPHs had a high percentage of essential amino acids, which made up 50.52 and 50.47%, of the protein hydrolysates obtained by the Alcalase and A21proteases, respectively. Therefore, THPHs can be used as a promising source of functional peptides with antioxidant properties. Functional properties and antioxidant activities of protein hydrolysates from tuna (Thunnus thynnus) heads (THPHs), with different degrees of hydrolysis, obtained by treatment with Bacillus mojavensis A21 alkaline proteases and Alcalase, were investigated. Protein content of all freeze-dried THPHs ranged from 73.74 ± 0.5 to 78.56 ±1.2%. The THPHs had excellent solubility, compared to untreated tuna head proteins and possessed interfacial properties, which were governed by their concentrations. Similarly, at a degree of hydrolysis (DH) of 12 and 15%,> 90% nitrogen solubility was observed at all experimental pH values tested. The emulsifying activity index (EAI) and emulsion stability index (ESI) of both hydrolysates at different DHs decreased (p < 0.05) with increasing DH. At low DH (5%), hydrolysates exhibited strong emulsifying properties. All THPHs produced by the A21 proteases generally showed higher antioxidative activity than that of the Alcalase protein hydrolysates. The highest DPPH radical-scavenging activity (78 ± 2.1% at 3 mg/mL) was obtained with a DH of 15%. The IC50 value for the β-carotene bleaching assay was 0.5 ± 0.03 mg/mL. Alcalase (DH = 12%) and A21 (DH = 15%) protein hydrolysates contained glutamic acid/glutamine and arginine as the major amino acids, followed by lysine, aspartic acid/asparagine, histidine, valine, phenylalanine, and leucine. In addition, the THPHs had a high percentage of essential amino acids, which made up 50.52 and 50.47%, of the protein hydrolysates obtained by the Alcalase and A21proteases, respectively. Therefore, THPHs can be used as a promising source of functional peptides with antioxidant properties.

Does one night of partial sleep deprivation affect the evening performance during intermittent exercise in Taekwondo players?

Mohamed Arbi Mejri,Narimen Yousfi,Thouraya Mhenni,Amel Tayech,Omar Hammouda,Tarak Driss,Anis Chaouachi,Nizar Souissi 한국운동재활학회 2016 JER Vol.12 No.1

RNA-Seq-based transcriptome profiling and expression of 16 cytochrome P450 genes in the benzo[α]pyrene-exposed estuarine copepod <i>Eurytemora affinis</i>

Lee, Bo-Young,Lee, Min-Chul,Jeong, Chang-Bum,Kim, Hee-Jin,Hagiwara, Atsushi,Souissi, Sami,Han, Jeonghoon,Lee, Jae-Seong Elsevier 2018 Comparative biochemistry and physiology. Part D, G Vol.28 No.-

<P><B>Abstract</B></P> <P>The calanoid copepod <I>Eurytemora affinis</I> is one of the most abundant estuarine species and is considered to be an ideal candidate species for ecotoxicological research. An RNA-Seq-based transcriptome was developed from whole bodies of this species. Among 142,442 contigs of the <I>de novo</I> assembly by Trinity, 48,480 open reading frame (ORF) contigs were found using TransDecoder. A total of 17,762 genes were identified by BLAST analysis, which covers about 75% of the annotated genes in the <I>E. affinis</I> genome. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that most annotated sequences were related to metabolism pathways, including xenobiotic biodegradation. Using transcriptome data, we identified putative transcripts related to xenobiotic processing genes including phase I enzymes, phase II enzymes, transporters, and transcription factors. To understand the CYP-mediated detoxification metabolism of xenobiotics, we measured the transcriptional levels of 16 CYPs (within full sequences) of <I>E. affinis</I> in response to benzo[α]pyrene (B[α]P). Most <I>Ea-CYP</I> genes were significantly down- and/or up-regulated (<I>P</I> < 0.05) in response to B[α]P, suggesting that <I>Ea-CYP</I> genes are likely involved in detoxification (mainly in biotransformation of xenobiotics) with particular genes, demonstrating significant upregulation or downregulation compared to others, as shown in other copepod model species (<I>e.g. Tigriopus japonicus</I> and <I>Paracyclopina nana</I>). This study will provide insight into the potential role of <I>E. affinis</I> in response to various toxic or xenobiotic chemicals in the marine environment.</P>

Effects of salinity on growth, fatty acid synthesis, and expression of stress response genes in the cyclopoid copepod <i>Paracyclopina nana</i>

Lee, Seung-Hwi,Lee, Min-Chul,Puthumana, Jayesh,Park, Jun Chul,Kang, Sujin,Hwang, Dae-Sik,Shin, Kyung-Hoon,Park, Heum Gi,Souissi, Sami,Om, Ae-Son,Lee, Jae-Seong,Han, Jeonghoon Elsevier 2017 Aquaculture Vol.470 No.-

<P><B>Abstract</B></P> <P>In marine ecosystems, salinity fluctuations are critical in modulating energy balance, inducing stress proteins, providing reproductive success and affecting the distribution of copepods. Salinity induces osmotic stress in organisms when they are not in their optimal condition and the stressful status increase the energy demand required for osmoregulation, which in turn reflects in all biological processes. Effects of salinity stress on life history traits and tolerance are species-specific. In this study, we used the estuarine cyclopoid copepod <I>Paracyclopina nana</I> to understand the responses towards the hypo (5ppt) and hypersalinity (25 and 30ppt) conditions, and compared that with the control (15ppt). We investigated the life cycle parameters (e.g. growth and fecundity), fatty acid (FA) synthesis, lipid accumulation (as lipid droplets [LDs]) and modulation of heat shock proteins (<I>hsps</I>) in response to salinity stress. As a result, life cycle parameters and FA synthesis, LDs, and modulation of <I>hsps</I> were found highly dependent on salinity changes in <I>P. nana</I>. Particularly, hypersalinity resulted in developmental retardation, reduced fecundity, decreased FA synthesis, a drop in lipid accumulation, and modulation of stress response proteins, suggesting that <I>P. nana</I> devoted increased energy to cope with the osmotic imbalance due to salinity stress in hypersalinity conditions. This finding provides a better understanding of how salinity affects in vivo endpoints and the relevant molecular responses in estuarine copepods.</P> <P><B>Statement of relevance</B></P> <P>We envisage that this manuscript will be helpful to understand salinity-dependent lipid composition changes in copepods and optimize the optimal salinity for the mass culture for this species.</P> <P>Considering the small size (~600μm) of <I>P. nana</I> and its potential as live feeds for finfish larviculture, the present findings have considerable importance for the aquaculture industry.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The P. nana devoted increased energy to cope with the osmotic imbalance due to salinity stress in hyper salinity condition. </LI> <LI> Life cycle parameters and FA synthesis, LDs, and modulation of hsps were found to be highly salinity dependent in P. nana. </LI> <LI> Hypersalinity resulted in in vivo life parameters, a drop in lipid accumulation, and modulation of stress response proteins. </LI> </UL> </P>

Short-term exposure to gold nanoparticle suspension impairs swimming behavior in a widespread calanoid copepod

Michalec, Franç,ois-Gaë,l,Holzner, Markus,Barras, Alexandre,Lacoste, Anne-Sophie,Brunet, Loï,c,Lee, Jae-Seong,Slomianny, Christian,Boukherroub, Rabah,Souissi, Sami Elsevier 2017 Environmental pollution Vol.228 No.-

<P><B>Abstract</B></P> <P>Calanoid copepods play an important role in the functioning of marine and brackish ecosystems. Information is scarce on the behavioral toxicity of engineered nanoparticles to these abundant planktonic organisms. We assessed the effects of short-term exposure to nonfunctionalized gold nanoparticles on the swimming behavior of the widespread estuarine copepod <I>Eurytemora affinis</I>. By means of three-dimensional particle tracking velocimetry, we reconstructed the trajectories of males, ovigerous and non-ovigerous females. We quantified changes in their swimming activity and in the kinematics and geometrical properties of their motion, three important descriptors of the motility patterns of zooplankters. In females, exposure to gold nanoparticles in suspension (11.4 <I>μ</I>g L<SUP>−1</SUP>) for 30 min caused depressed activity and lower velocity and acceleration, whereas the same exposure caused minimal effects in males. This response differs clearly from the hyperactive behavior that is commonly observed in zooplankters exposed to pollutants, and from the generally lower sensitivity of female copepods to toxicants. Accumulation of gold nanoparticles on the external appendages was not observed, precluding mechanical effects. Only very few nanoparticles appeared sporadically in the inner part of the gut in some samples, either as aggregates or as isolated nanoparticles, which does not suggest systemic toxicity resulting from pronounced ingestion. Hence, the precise mechanisms underlying the behavioral toxicity observed here remain to be elucidated. These results demonstrate that gold nanoparticles can induce marked behavioral alterations at very low concentration and short exposure duration. They illustrate the applicability of swimming behavior as a suitable and sensitive endpoint for investigating the toxicity of nanomaterials present in estuarine and marine environments. Changes in swimming behavior may impair the ability of planktonic copepods to interact with their environment and with other organisms, with possible impacts on population dynamics and community structure.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We studied the motion of copepods exposed to non-functionalized gold nanoparticles. </LI> <LI> Exposure depressed swimming activity and velocity in females but not in males. </LI> <LI> This response differs from the hyperactivity commonly observed with pollutants. </LI> <LI> We observed accumulation neither in the digestive track nor on the appendages. </LI> <LI> Nanomaterials can induce marked behavioral toxicity at very low concentrations. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Microplastic Size-Dependent Toxicity, Oxidative Stress Induction, and p-JNK and p-p38 Activation in the Monogonont Rotifer (<i>Brachionus koreanus</i>)

Jeong, Chang-Bum,Won, Eun-Ji,Kang, Hye-Min,Lee, Min-Chul,Hwang, Dae-Sik,Hwang, Un-Ki,Zhou, Bingsheng,Souissi, Sami,Lee, Su-Jae,Lee, Jae-Seong American Chemical Society 2016 Environmental science & technology Vol.50 No.16

<P>In this study, we evaluated accumulation and adverse effects of ingestion of microplastics in the monogonont rotifer (Brachionus koreanus). The dependence of microplastic toxicity on particle size-was investigated by measuring several in vivo end points and studying the ingestion and egestion using 0.05-, 0.5-, and 6-mu m nonfunctionalized polystyrene microbeads. To identify the defense mechanisms activated in response to microplastic exposure, the activities of several antioxidant-related enzymes and the phosphorylation status of mitogen-activated protein kinases (MAPKs) were determined. Exposure to polystyrene microbeads of all sizes led to significant size dependent effects, including reduced groWth rate, reduced fecundity, decreased lifespan and longer reproduction time. Rotifers exposed to 6-mu m fluorescently labeled microbeads exhibited almost no fluorescence after 24 h, while rotifers exposed to 0.05- and 0.5-mu m fluoresceatly labeled inicrobeads displayed fluorescence until 48 h, suggesting that 6-mu m microbeads are more effectively egested from B. koreanus than 0.05- or 0.5-mu m microbeads. This observation provides a potential explanation for our findings that microbead toxicity was size dependent and smaller microbeads were more toxic. In vitro tests revealed that antioxidant-related enzymes and MAPK signaling pathways were significantly activated in response to microplastic exposure in a size-dependent manner.</P>