PHB Group Research Articles

Analisis Perencanaan Sistem Jaringan Distribusi Listrik dan Perkembangan Beban Pada Perumahan The Grand Kenjeran Surabaya

he electric power system is a system consisting of several parts, namely generating units, transmission units, distributionunits, and load units that are interconnected and work together to serve the electricity needs of customers according to their needs. In theprocess itself, electrical energy is distributed from the generator through the transmission network until it is received by consumers orcustomers so that in this case a related plan is needed. Planning here aims to get an optimal service flexibility so that it is able to quicklyanticipate the growth of electrical energy and how dense the load that must be served. So that the planning of the electricity distributionnetwork system must pay attention to the load conditions in the field, this is intended so that the planned distribution network system can stillwork well for the next few years. The data collection method used is in the form of field observations which aim to determine field conditionsand obtain load data that will be planned. The results of research conducted at The Grand Kenjeran Surabaya housing show that there are76 housing units to be built in this housing. The 76 housing units will be divided into 4 blocks D, E, F, G and are planned with an initial powerof 5500 VA for each housing unit along with Public Road Planning in residential areas. Taking into account field conditions, ground cablesare used as a distribution network system which includes SKTM and SKTR. The total power obtained is 435,107.5 VA and is served by 3units of distribution transformer using Pole Transformer Substation, 3 PHB-TR, 12 Main PHB, and 3 Branch PHB. The magnitude of thepossible voltage drop is around 0.97% for medium voltage, 0.3% - 0.92% for Main PHB group, 0.7% - 1.54% for Branch PHB group.

Supernucleation, crystalline structure and thermal stability of bacterially synthesized poly(3-hydroxybutyrate) polyester tailored by thymine as a biocompatible nucleating agent

Naturally occurring thymine (TM) was incorporated into bacterial poly(3-hydroxybutyrate) (PHB) polyester to fabricate a novel and green biocomposite. Both 0.5% and 1% TM exhibit supernucleation effect on PHB, and crystallization kinetics suggests TM significantly increased Tc and Xc, and substantially shortened t1/2 of PHB. Epitaxial nucleation caused by a perfect crystal lattice matching between PHB and TM, was proposed to elucidate nucleation mechanism of PHB. Hydrogen bond interaction exists between CO, C–O–C groups of PHB and –CH3 (or –CH)/–NH– group of TM. TM interacted with CO group of PHB crystalline phase rather than that of amorphous one. In addition, two new IR crystalline bands assigned to C–O–C group of PHB appeared in the presence of TM, which arises from shift of two amorphous ones, respectively. TM enhanced onset thermal degradation temperature of PHB, mainly attributed to increased degree of crystallinity of PHB and flame retardance effect of TM.

Synthesis, characterization and antimicrobial activity of biguanidinylated chitosan-g-poly[(R)-3-hydroxybutyrate

Chitosan biguanidine hydrochloride (ChG) and low molecular weight poly[(R)-3-hydroxybutyrate] (PHB) were successfully prepared to overcome the solubility problem of chitosan and PHB and also to enhance antimicrobial activity of chitosan. The graft copolymers based on ChG and PHB (ChG-grafted PHB) were then prepared via condensation reaction of the carboxylic groups of PHB with the amino groups of ChG. These graft copolymers swell in water. The prepared graft copolymers were characterized by FTIR, 1H NMR, X-ray diffraction (XRD) and thermal analyses (TGA and DSC). TGA and DSC results revealed that the thermal stability and crystallinity of the graft copolymers were found to increase as the content of PHB increased. The antimicrobial activity of both ChG and ChG-grafted PHB, against Streptococcus pneumoniae, Bacillus subtilis, Escherichia coli (as examples of bacteria) and Aspergillus fumigatus, Geotricum candidum and Syncephalastrum recemosum (as examples of fungi), were tested. Among them, ChG and ChG-grafted PHB with the highest grafting percent investigated showed to possess relatively higher antimicrobial activity with low MIC values in the range of 0.49–3.90μgmL−1.

Characterization of a polyhydroxyalkanoate obtained from pineapple peel waste using Ralsthonia eutropha

Agro-industrial waste can be the production source of biopolymers such as polyhydroxyalkanoates. The aim of this study was to produce and characterize Polyhydroxyalkanoates produced from pineapple peel waste fermentation processes. The methodology includes different pineapple peel waste fermentation conditions. The produced biopolymer was characterized using FTIR, GC–MS and NMR. The best fermentation condition for biopolymer production was obtained using pH 9, Carbon/Nitrogen 11, carbon/phosphorus 6 and fermentation time of 60h. FTIR analyzes showed PHB group characteristics, such as OH, CH and CO. In addition, GC–MS showed two monomers with 4 and 8 carbons, referred to PHB and PHBHV. H1 NMR analysis showed 0.88–0.97 and 5.27ppm signals, corresponding to CH3 and CH, respectively. In conclusion, polyhydroxyalkanoate production from pineapple peels waste is an alternative for the treatment of waste generated in Colombia’s fruit industry.

THE INFLUENCE OF PHOTOHAEMOTHERAPY ON BLOOD RHEOLOGY IN BRONCHIAL ASTHMA

Background: Blood rheology abnormalities are recognized as one of the main pathophysiological components of bronchial asthma. Standard medical treatment of bronchial asthma does not exert any substantial effect on blood fluidity. Aim: To assess efficacy of quantum haemotherapy and its influence on blood rheology in the combination treatment of bronchial asthma. Materials and methods: Four hundred and eighty patients admitted to our in-patient department with mild (44.5%) and severe (55.5%) exacerbations of persistent moderate asthma, were randomized into two groups: the main group (n = 250), which, along with conventional treatment, received photohaemotherapy with blue (PHB, n = 220) or red (PHR, n = 30) light, and the control group (n = 230), which received conventional treatment for two weeks. PHB (light-emitting diode devise “Solaris”) and PHR (helium neon laser) was performed according to the following regimen: duration of a session 30 minutes, number of sessions, from 5 to 7 with in-between intervals of 2 to 3 days. The degree of erythrocyte deformation, relative membrane charge and relative gradient membrane potential of erythrocytes, total erythrocyte counts, hemoglobin levels, hematocrit, and blood viscosity were assessed at days 1 and 14, as well as after 3 months. Results: At day 14, the relative gradient membrane potential of erythrocytes decreased to 0.118 ± 0.01 r.u. in the PHB group, to 0.167 ± 0.01 r.u. in the PHR group, and to 0.153 ± 0.01 r.u. in the conventional treatment group. The relative charge of erythrocyte membranes increased to 0.202 ± 0.07, 0.19 ± 0.07 and 0.14 ± 0.07 r.u., the degree of erythrocyte deformation decreased to 1.4 ± 0.1, 1.6 ± 0.1 and 1.9 ± 0.1 scores, the degree of hypoxic anisotropy of the serum decreased to 0.8, 0.9 and 1.2 scores, respectively (in all cases, p 0.05). At month 3, all patients, despite their clinical well-being, demonstrated a deterioration of the parameters studies. However, only in the conventionally treated group the degree of this deterioration was compatible with parameters registered during an asthma exacerbation. Conclusion: Blood rheology parameters demonstrated a more rapid and advanced improvement in patients with exacerbations of bronchial asthma, who were treated with the use of photohaemotherapy, compared to those who received conventional treatment only.

Intermolecular hydrogen bondings in the poly(3-hydroxybutyrate) and chitin blends: Their effects on the crystallization behavior and crystal structure of poly(3-hydroxybutyrate)

Crystallization behavior and intermolecular hydrogen-bonding interactions of poly(3-hydroxybutyrate) (PHB)/chitin blends on as-solution cast films were studied as a function of composition and temperature by differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD) and infrared (IR) spectroscopy. The significant changes were observed in the DSC curves, WAXD patterns and IR spectra of the blends with PHB ≤50 wt%. We found that the crystallinity of PHB decreases in the blends, however, its crystal structure is not much affected by blending with chitin. The appearance of a new band at around 1710–1714 cm−1 clearly reveals the formation of intermolecular hydrogen bondings between the CO groups of PHB and the O–H and N–H groups of chitin (CO⋯H–O and CO⋯H–N). It is very likely that these intermolecular CO⋯H–N and CO⋯H–O hydrogen bondings occur in the amorphous phase because of the reduction in the chain mobility in the blends with increasing chitin content, even above the melting temperature of PHB. The CO⋯H–N and CO⋯H–O hydrogen bondings are formed upon the cleavage of weak CO⋯H3C hydrogen bondings of PHB. Thus, the formation of the CO⋯H–N and CO⋯H–O hydrogen bondings is accompanied by the decrease in the crystallinity of PHB in the blends.

Plasticized poly(lactic acid)-poly(hydroxybutyrate) (PLA-PHB) blends incorporated with catechin intended for active food-packaging applications.

Active biobased packaging materials based on poly(lactic acid)-poly(hydroxybutyrate) (PLA-PHB) blends were prepared by melt blending and fully characterized. Catechin incorporation, as antioxidant compound, enhanced the thermal stability, whereas its release was improved by the addition of acetyl(tributyl citrate) (ATBC) as plasticizer. Whereas the incorporation of ATBC resulted in a reduction of elastic modulus and hardness, catechin addition produced more rigid materials due to hydrogen-bonding interactions between catechin hydroxyl groups and carbonyl groups of PLA and PHB. The quantification of catechin released into a fatty food simulant and the antioxidant effectiveness after the release process were demonstrated. The effect of the materials' exposure to a food simulant was also investigated. PHB-added materials maintained their structural and mechanical properties after 10 days in a test medium that represents the worst foreseeable conditions of the intended use. Thus, plasticized PLA-PHB blends with catechin show their potential as biobased active packaging for fatty food.

The effect of poly(vinyl phenol) sublayer on the crystallization and melting behavior of poly(3-hydroxybutyrate) via hydrogen bonds

The cold crystallization and melting behavior of poly(3-hydroxybutyrate)(PHB) layer on amorphous Poly(vinyl phenol) (PVPh) and Si wafer substrate were studied by using Grazing incidence X-ray diffraction and infrared reflection-absorption spectroscopy. Compared to the PHB on Si wafer, the PVPh layer shows great influence on the crystallization and melting behavior of PHB layer. The depression extent of melting temperature increases with the increase of PVPh thickness when the thickness of PVPh is smaller than a critical value. Infrared reflection-absorption spectroscopy study is carried out to better understand the structure evolution of PHB and its interaction with PVPh in the heating process. By monitoring and decomposing the CO stretching bands, several points can be identified: (1) melting temperature decreases with PVPh thickening; (2) the fraction of intermolecular hydrogen bonds formed between the OH groups of PVPh and CO groups of PHB is very small below glass transition temperature of PVPh and it increases significantly above 100 °C. Moreover the fraction increases with PVPh thickness. The effect of PVPh thickness on the formation of hydrogen bonds is attributed to the roughness, molecular mobility and/or molecular orientation of PVPh.

Thermal stability and miscibility of poly(hydroxybutyrate) and soda lignin blends

The thermal properties and miscibility of poly(hydroxybutyrate) (PHB) and soda lignin blends were investigated by thermogravimetry analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and Fourier transform infra-red spectroscopy (FTIR) over the entire range of composition. Although the addition of soda lignin shifts the onset of PHB decomposition to lower temperatures, the PHB/lignin blends are thermally more stable than PHB over a wider temperature range. The thermal behaviour of these blends as measured by TGA suggests compatibility for the blends containing up to 40 wt% soda lignin. These results correlate well with the glass transition temperature ( T g ) data where a single T g was obtained for these blends. At higher lignin to PHB ratios, two T g s depicting immiscibility were obtained. The infra-red data show that the miscibility of the blends containing up to 40 wt% soda lignin is associated with specific hydrogen bonding interactions between the reactive functional groups in lignin with the carbonyl groups of PHB.

Miscibility enhancement through hydrogen bonding interaction of biodegradable poly(3‐hydroxybutyrate) blending with poly(styrene‐co‐vinyl phenol) copolymer

AbstractDifferential scanning calorimetry, one‐ and two‐dimensional Fourier transform infrared (FTIR), and solid state nuclear magnetic resonance (NMR) spectroscopy have been used to investigate the miscibility of and specific interactions between poly(styrene‐co‐vinyl phenol) (PSOH) and poly(3‐hydroxybutyrate) (PHB) upon varying the vinyl phenol content of the PSOH copolymer. The FTIR and solid state NMR spectra revealed that the phenol units of PVPh interact with the carbonyl groups of PHB through intermolecular hydrogen bonding. A miscibility window exists when the vinyl phenol fraction in the copolymer is greater than 22 mol % in the PSOH/PHB blend system, as predicted using the Painter–Coleman association model. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Hypocholesterolemic and antioxidative effects of naringenin and its two metabolites in high-cholesterol fed rats

This study was conducted to compare the hypocholesterolemic and antioxidant effects of naringenin (0.02%), and its metabolites, rho-hyproxyphenylpropionic acid (PHPP, 0.012%) and rho-hydroxybenzoic acid (PHB, 0.012%), in 1% cholesterol diet-fed rats. All supplements significantly lowered the plasma total-cholesterol (total-C), triglyceride (TG) and atherogenic index, and hepatic cholesterol levels compared with the control group. The plasma high-density lipoprotein-cholesterol (HDL-C) concentration was significantly higher in these supplemented groups. However, PHB group only affected the reduction of hepatic TG content. The hydroxyl-3-methylglutaryl-coenzyme A reductase (HMGR) activity was significantly lower in all supplemented groups, whereas only the naringenin group reduced the acyl-coenzyme A:cholesterol acyltransferase (ACAT) activity compared with the control group. The fecal acidic sterol excretion and hepatic superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities were significantly higher in all supplemented groups. All supplements also significantly decreased the contents of plasma and hepatic thiobarbituric acid reactive substances (TBARS). Accordingly, it was considered that naringenin and its metabolites were effective on improving the cholesterol and antioxidant metabolism.

Thermal and crystallization behavior of hydrogen‐bonded miscible blend of poly(3‐hydroxybutyrate) and enzymatically polymerized polyphenol

AbstractEnzymatically prepared novel polyphenol poly(4,4′‐dihydroxydiphenyl ether) (PDHDPE) is blended to modify the properties of biodegradable polyester poly[(R)‐3‐hydroxybutyrate] (PHB). Because the differential scanning calorimetry data show a single composition‐dependent glass transition for each blend, PHB and PDHDPE are found to be miscible in the amorphous phase. The crystallization of PHB is depressed by PDHDPE because PDHDPE reduces the molecular mobility and the flexibility of molecular chains of PHB. The Fourier transform IR spectra clearly indicate that PHB and PDHDPE interact through strong intermolecular hydrogen bonds between the carbonyl groups of PHB and the hydroxyl groups of PDHDPE. However, when PHB is blended with DHDPE monomer, no obvious hydrogen bonds are observed because of the phase separation and strong self‐intermolecular hydrogen bonds between DHDPE molecules. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 2439–2449, 2005

A MAC Protocol for IP Differentiated Services in a WDM Metropolitan Area Network

This paper presents a Media Access Control (MAC) protocol for a WDM passive optical star. The protocol supports scalable service differentiation for Internet traffic in the spirit of the IETF's Diffserv architecture. We describe the functional elements of the protocol (signaling, arbitration, service disciplines and buffer management techniques) and the way they interact to support the Diffserv's Expedited Forwarding (EF) PHB and Assured Forwarding (AF) PHB group, where PHB stands for Per-Hop-Behavior. Extensive simulation results give quantitative estimations of the performance of the protocol under combined EF/AF traffic.

Molecular dynamics of the spin probes in dry and wet poly(3-hydroxybutyrate) films with different morphology

The molecular mobilities of the spin probes TEMPO and TEMPOL in microbial poly(3-hydroxybutyrate) (PHB) have been studied by the ESR method in a range of temperatures from 293 to 363K. The spectra of the dry and wet films with isotropic and textured morphology are analyzed as a spectral superposition of the “fast-” and “slow-rotating” fractions. Nonpolar TEMPO is sensitive to structural heterogeneity and practically nonsensitive to water sorption. The polar TEMPOL can interact with the carbonyl groups of PHB and the ESR spectra are affected by water molecules. The differences of spectral characteristics between the textured and isotropic PHB films are manifested in the rotation mobility (rotation correlation times) and the mole fractions of the “fast-” and “slow-rotating” ESR probes.Comparison of ESR data with water diffusivities in the textured and isotropic samples reveals the relationship between transport phenomena and morphology of the novel biopolymer material.

Modification via preparation for poly(3-hydroxybutyrate) films: Water-transport phenomena and sorption

The effect of the preparation technique on the sorption-diffusion parameters of poly(3-hydroxybutyrate) (PHB) films was studied. The films formed by a single-stage technique have an axial texture of the crystalline phase, with the polymer chain oriented predominantly perpendicularly to the film plane. Moreover, the crystallites in PHB are preferably ordered in stacks in the course of diffusion; the alignment of the crystallites noticeably decreases the sites of PHB (polar groups) which are accessible to water molecules. As a result, the sorption capacity decreases but the rate of diffusion increases. On the contrary, PHB films prepared by a two-stage technique are characterized by a poor ordering of crystallites without texture organization. Here, the sorption/immobilization on the polar groups of PHB is increased, but diffusivities are decreased. Concentration dependencies of the water-diffusion coefficient are discussed. Additional information on the existence of protein impurities in the PHB samples obtained by the above two preparation techniques was obtained by FTIR spectroscopy and H-D exchange methods.

Water Sorption and Diffusion in Poly-(3-Hydroxybutyrate) Films

For improved understnding of the transport of low-molecular substances' in moderately hydrophobic polymers, the temperature dependence of water vapor sorption and diffusion in poly-(3-hydroxybutyrate) (PHB) was studied for the first time. Equilibrium sorption and diffusion kinetics were determined by a quartz McBain's vacuum microbalance technique in the temperature range 303-333 K. The water molecule interaction with the polymer matrix was analyzed for wet PHB films by the Fourier transform infrared spectroscopy technique. Water sorption isoterms are interpreted as a superposition of free water sorption estimated by the Flory-Huggins equation and water immobilized on car-bony 1 groups of PHB. The immobilization effect was described by a Lmgmuir-type equation. The dependence of diffusivity on water concentration was described in the framework of Fujita's immobilization model in which the growing function D w versus C w characterized the filling degree of carbonyl groups as sites of immobilization in the polymer. Enthalpy of free water sorption (12 kJ/mol) and water immobilization (42 kJ/mol) as well as the activation energy of water diffusion coefficients (71 kJ/mol) in noncrystalline areas of PHB were determined.

Immobilization influence on the water sorption and diffusion in poly(3-hydroxybutyrate)

The temperature dependency of water vapor sorption and diffusion in poly(3-hydroxybutyrate) (PHB) was studied for the first time. Equilibrium sorption and diffusion kinetics were determined by a quartz McBain's vacuum microbalance technique in the temperature range of 303–333 K. A probability of water molecule interaction with the polymer matrix was analyzed for wet PHB films by FTIR spectroscopy technique. Sorption isotherms are interpreted as the solution of free water molecules estimated by the Flory–Huggins equation and the sorption of water molecules immobilized on the carbonyl groups of PHB. The immobilization effect was described by a Langmuir-type equation. The dependency of diffusivity on water concentration was described in the frames of Fujita's immobilization model in which the growing function Dw versus Cw characterized the filling degree of carbonyl groups as sites of immobilization in the polymer. Enthalpy of free water sorption (12 kJ/mol) and water immobilization (42 kJ/mol), as well as the activation energy of water diffusion coefficients (71 kJ/mol), in noncrystalline areas of PHB were determined. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 981–985, 1999

Thermal properties and crystallization behavior of poly(3-hydroxybutyric acid) in blends with chitin and chitosan

Films of blends of microbial poly(3-hydroxybutyric acid) (PHB) with α-chitin and chitosan were prepared as completely biodegradable polyester-polysaccharide composites. DSC revealed that the crystallization of PHB in these blends is suppressed when the proportion of the polysaccharide is increased. The same tendency was evident from the FT-IR band intensity of the carbonyl stretching absorption from PHB. Chitosan was found to have a stronger ability to suppress the crystallization of PHB than α-chitin. PHB in the blends was found by 13C NMR spectroscopy to be trapped in the `glassy' environment of the polysaccharide. Upon blending with PHB, the chitosan resonances are significantly broadend as compared to the chitin resonances. Hydrogen bonds are suggested to be formed between the carbonyl groups of PHB and the amide NH groups of chitin and chitosan.

Water Sorption and Diffusion in Poly(S-hydroxybutyrate) Films

The temperature dependence of water vapour sorption and diffusion in poly-(3-hydroxybutyrate) (PHB) was investigated. Equilibrium sorption and diffusion kinetics were determined by a quartz Mac Bain's vacuum microbalance technique in the temperature range of 303–333 K. The water molecule interaction with the polymer matrix was analyzed for wet PHB films by FTIR spectroscopy technique. Water sorption isotherms are interpreted as a superposition of free water sorption, estimated by the Flory-Huggins equation and water immobilized on carbonyl groups of PHB. The immobilization effect was described by a Langmuir type equation. The dependence of diffusivity on water concentration was described in the framework of Fujita's immobilization model in which the growing function Dw vs Cw . characterized the filling degree of carbonyl groups as sites of immobilization in the polymer. Enthalpy of free water sorption (12kJ/mol) and water immobilization (42kJ/mol) as well as the activation energy of water diffusion coefficients (71kJ/mol) in noncrystalline areas of PHB were determined.

Miscibility in blends of poly(3-hydroxybutyrate) and poly(vinylidene chloride-co-acrylonitrile)

Miscibility behavior of poly(3-hydroxybutyrate) [PHB]/poly(vinylidene chloride-co-acrylonitrile) [P(VDC-AN)] blends have been investigated by differential scanning calorimetry and optical microscopy. Each blend showed a single Tg, and a large melting point depression of PHB. All the blends containing more than 40% PHB showed linear spherulitic growth behavior and the growth rate decreased with P(VDC-AN) content. The interaction parameter χ12, obtained from melting point depression analysis, gave the value of −0.267 for the PHB/P(VDC-AN) blends. All results presented in this article lead to the conclusion that PHB/P(VDC-AN) blends are completely miscible in all proportions from a thermodynamic viewpoint. The miscibility in these blends is ascribed to the specific molecular interaction involving the carbonyl groups of PHB. © 1997 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 35: 2645–2652, 1997