**3. Radiation and polysaccharides**

Carbohydrates or saccharides are polyhydroxy aldehydes or ketones that have the empirical formula (CH2O)n. Most of the carbohydrates found in nature occur as polysaccharides of high molecular weight. Polysaccharides are polymers of monosaccharides linked with glycosidic bonds containing usually no more than two kinds of residues. The most abundant monosac‐ charide is the six-carbon sugar D-glucose; it is the primordial monosaccharide from which all others are derived. D-Glucose is the most important fuel molecule for most organisms, and also the basic building block of the most abundant polysaccharides. The monomeric units contain many hydroxyl groups, which can engage in intra- and inter-molecular formation of hydrogen bonds. This hydrogen bonding keeps the chains together and contributes to the high tensile strength of the polymeric material. Other forms of functionalization can also occur.

Polysaccharide films are made from starch, alginate, cellulose ethers, chitosan, carageenan, or pectins and impart hardness, crispness, compactness, thickening quality, viscosity, adhesive‐ ness and gel-forming ability to a variety of films. These films usually exhibit good gas permeability properties, resulting in desirable modified atmospheres that enhance the shelf life of the product without creating anaerobic conditions. Additionally, polysaccharide films and coatings can be used to extend the shelf life of muscle foods by preventing dehydration, oxidative rancidity and surface browning, but their hydrophilic nature makes them poor barriers for water vapor.

radiation exposure time and the distance between the product and the radiation source in the

The long molecular chains of polymers can be broken by the absorption of a quantum of energy above the energy of the covalent bond of the main carbon chain, which typically is in the range of 5–10 eV. The energy of beta and gamma photons of 1 to 10 MeV surpasses by many orders of magnitude this minimum value, representing a high probability of affecting all kinds of polymers, naturals and synthetics alike [12]. Usually, there is a competition between crosslinking and chain scission reaction. If chain scission reaction predominates the material

Radiation, as a non-selective, highly efficient tool of ionization, may form excited sites, ions and free radicals in almost all kinds of materials. Radiation treatment of polymer mixtures, even if they are (partially) incompatible, gives a chance for bridge-forming bonds [13].

The key effect of radiation is the production of reactive oxygen species (ROS), which affects biomolecules (e.g., lipid, protein, polysaccharides). One of the important radiation-induced free-radical species is the hydroxyl radical, which indiscriminately attacks neighboring molecules often at near diffusion-controlled rates. Hydroxyl radicals are generated by ionizing radiation either directly by oxidation of water, or indirectly by the formation of secondary partially ROS. These may be subsequently converted to hydroxyl radicals by further reduction ("activation"). Secondary, radiation injury is therefore influenced by the surrounding antiox‐ idant status and the amount and availability of activating mechanisms. The biological response to radiation may be modulated by alterations in factors affecting these secondary mechanisms

Carbohydrates or saccharides are polyhydroxy aldehydes or ketones that have the empirical formula (CH2O)n. Most of the carbohydrates found in nature occur as polysaccharides of high molecular weight. Polysaccharides are polymers of monosaccharides linked with glycosidic bonds containing usually no more than two kinds of residues. The most abundant monosac‐ charide is the six-carbon sugar D-glucose; it is the primordial monosaccharide from which all others are derived. D-Glucose is the most important fuel molecule for most organisms, and also the basic building block of the most abundant polysaccharides. The monomeric units contain many hydroxyl groups, which can engage in intra- and inter-molecular formation of hydrogen bonds. This hydrogen bonding keeps the chains together and contributes to the high tensile strength of the polymeric material. Other forms of functionalization can also occur.

Polysaccharide films are made from starch, alginate, cellulose ethers, chitosan, carageenan, or pectins and impart hardness, crispness, compactness, thickening quality, viscosity, adhesive‐ ness and gel-forming ability to a variety of films. These films usually exhibit good gas permeability properties, resulting in desirable modified atmospheres that enhance the shelf life of the product without creating anaerobic conditions. Additionally, polysaccharide films

irradiation camera.

164 Radiation Effects in Materials

degrades.

[14].

**3. Radiation and polysaccharides**

Starch contains only D-glucose as monomeric units and occurs in two forms, α-amylose (a long unbranched chain) and amylopectin (highly branched). Films produced from pure starch are generally brittle and difficult to handle, although there are some exceptional reports that starches such as cassava can make transparent and colorless flexible films without any previous chemical treatment [15].

Other polysaccharides like pectin, pullulan and chitosan, coming from different origins, present different capability of acting as edible active coatings [16].

The poor mechanical properties and water stability of starch have restricted its industrial applications. However, they can often be functionalized with carboxyl groups, phosphate groups and/or sulfuric ester groups, and the combination of plasticizers and surfactants can bring the enhancement of properties of the starch films [17, 18].

The development of biodegradable materials based on starch has become an attractive option and the production of starch-based plastics is gradually obtained considerable importance in the world. Chemical modifications (e.g., cross-linking) or using a second biopolymer in the starch-based composite have been studied as strategies to produce low water-sensitive and relatively high-strength starch-based materials [19–22].

Particularly, citric acid showed to cross-link starch and improve the tensile strength, thermal stability and decrease the dissolution of starch films in water and formic acid [23].

Starch is considered easily depolymerizable by radiation treatment. Gamma and electron beam irradiation are used to induce radiation degradation of chitosan, alginate, carrageenan, cellulose, pectin, for recycling these bio-resources and reducing the environmental pollution. These carbohydrates, when degraded by radiation, present various kinds of biological activities such as promotion of plant growth, anti-microbial activity, phytoalexins induction, biocontrol elicitors and also can be added to aquaculture and animal feed to enhance immunity of animals [24, 25].

The radiation starch or dextrin degradation is a clean and safety tool. The process is very efficient and can be easily controlled by choosing a proper irradiation dose. A dose of 4.4 kGy, for instance, was enough to decrease the molar mass of wheat starches by one order of magnitude [26]. Other works describe the action of gamma radiation on potato, bean and maize starches [27–29].

Physical and structural characteristics of rice flour and starch obtained from gamma-irradiated white rice were determined. Pasting viscosities of the rice flour and starch decreased contin‐ uously with the increase in irradiation dosage. Gamma irradiation had no significant effect on the amylopectin branch chains, but produced more branch chains when the irradiation dosage was less than 9 kGy. It might be deduced that gamma irradiation caused the breakage of the amylopectin chains at the amorphous regions, but had little effects on the crystalline regions of starch granules, especially at low-dosage irradiation [30].

Several other reports were published about the beneficial use of gamma radiation on the improvement of properties of different biopolymeric materials. Ionizing radiation was employed for the synthesis of polysaccharide derivatives to be used as oral delivery system for a colon-specific drug carrier [31]; other works mention the increase of mechanical and barrier properties of polysaccharide materials and the induction of grafting of methylcellulosebased films [32].

Some authors reported the development of edible films from potato peel. High-pressure, gamma rays and ultrasound were applied to potato peel solutions to break down biopolymer particles in the solution small enough to allow for biopolymer film formation. Film properties, including moisture barrier and tensile properties, color and microstructures, were investigated from the films formed with different concentrations of plasticizer (glycerol) and emulsifier (soy lecithin). The authors concluded that the concentrations of both plasticizer (glycerol) and emulsifier (soy lecithin) were important variables in producing biopolymer films from potato peel [33].


*Edited by Kevin Kuang*

This book provides an introductory overview of the research done in recent years in the area of magnetic sensors. The topics presented in this book range from fundamental theories and properties of magnets and their sensing applications in areas such as biomedicine, microelectromechanical systems, nano-satellites and pedestrian tracking. Written for the readers who wished to obtain a basic understanding of the research area as well as to explore other potential areas of applications for magnetic sensors, this book presents exciting developments in the field in a highly readable manner.

ISBN 978-953-51-0232-8

Magnetic Sensors - Principles and Applications

Photo by Josef Reiter / iStock


*Edited by Shimon Rumelt*

This book focuses on the different aspects of ophthalmology - the medical science of diagnosis and treatment of eye disorders. Ophthalmology is divided into various clinical subspecialties, such as cornea, cataract, glaucoma, uveitis, retina, neuroophthalmology, pediatric ophthalmology, oncology, pathology, and oculoplastics. This book incorporates new developments as well as future perspectives in ophthalmology and is a balanced product between covering a wide range of diseases and expedited publication. It is intended to be the appetizer for other books to follow. Ophthalmologists, researchers, specialists, trainees, and general practitioners with an interest in ophthalmology will find this book interesting and useful.

ISBN 978-953-51-0248-9

Advances in Ophthalmology

Photo by Ericshiaw / iStock


**Abstract**

Most of diabetes care of outpatients takes place at their families. Family members who may have inadequate or lack diabetes knowledge are expected to offer home care, predisposing patients to poor outcomes and associated health problems. To review and discuss literature related to family-centered diabetes care. Comprehensive Literature Review was used to collect data by reviewing literature related to family centered diabetes care. Literature review involved evaluating discoveries of other researchers. The results of literature review showed that familycentered care is essential for better diabetes outcomes and preventing new cases. So far, family-centered care was successful in children's diabetes care and may be beneficial for older outpatients. Family-centered diabetes care improves knowledge of both patients and families, minimize prevalence and improve diabetes outcomes of outpatients.

**Keywords:** family centered diabetes care, diabetes, family, outpatients, literature review


**2. The 1987 Eastern Gulf of Mexico Red Tide Event**

On August 24, 1987, a breakout of the Red Tide was reported off the coast of Naples, Florida, in the GOM. As the oceanic currents flow, Naples is *On the Possibility of Non-Local and Local Oil Spills Striking the Shores of North Carolina... DOI: http://dx.doi.org/10.5772/intechopen.106679*

approximately 1600 kilometers (1010 miles), from the coasts of the Carolinas. If the Red Tide plants were able to jump aboard the Loop Current in the Gulf of Mexico, they could have been transported down the west Florida coast, around the Florida Keys, through the Florida Straits where it would have become part of the westward flowing Antilles Current and then loaded into the northward flowing Florida Current, which then becomes the northward flowing Gulf Stream (**Figure 1**). From the east coast of Florida, the organism would have had to have traveled north reaching Onslow Bay NC and Long Bay NC/SC outer shelf waters sometime in early October. Let us first consider the conditions that were present at the time.

In **Figure 2a**, the NOAA National Weather Service (NWS) atmospheric pressure map for August 24, 1987 shows a high-pressure center located in the southeastern USA. The winds associated with this weather system on the west Florida shelf would have been to the south, thereby effecting an offshore transport of surface waters via an Ekman surface layer [3] from the shelf into the eastern side of the GOM Loop Current. Two weeks hence, we find a low-pressure center or atmospheric cyclone located in the southeast, as shown in the September 7 weather map in **Figure 2b**. The winds are to the north on the eastern Atlantic Florida shelf, thereby driving surface coastal waters offshore, again via Ekman surface layer dynamics [3, 4], into the Gulf Stream. Therefore, while the Red Tide organisms were likely in the area of the east Florida shelf, winds were unfavorable for onshore transport out of the western edge of the Gulf Stream and onto the shelf. Therefore, the organisms stayed in the Gulf Stream, on its western side, marching northward. They could have gone from the western side of the Gulf Stream via the Astronomical Tides or due to Gulf Stream–related phenomena. We investigate that further below in Sections 3, 4, and 5.

**Figure 1.** *The Loop, Antilles and Florida Currents, and the Gulf Stream (from [2]).*

**Figure 2.**

*NWS 500 mb surface pressure maps. (a) Left image is August 24, 1987; (b) right image is September 8 1987. These maps are hard copies of those produced by the NWS and are copied with full fidelity.*


**2. Results and Discussion**

#### *2.1. Design and Synthesis of CHOS-based Affinity Resin*

Reversible inhibitor or substrate analogue are commonly used for the design of biomimetic affinity ligands of enzymes, due to the mild and efficient affinity values [17]. Chitooligosaccharides (CHOS) are natural cationic saccharides, while the catalytic domain of chitosanases is rich in acidic amino acids [12,13]; the acid-base interactions between the two molecules can provide affinity force during affinity purification. Immobilization of a ligand onto epoxy-activated resin can be achieved via nucleophilic groups (often is primary amine) presented in the ligand [14,19–22]. Because CHOS contains an amine group at the C-2 position of the sugar ring, we thus focused our efforts on the design of CHOS-based affinity resin for purification of chitosanase. The natural properties of affinity resins—in other words the selection of affinity ligands and spacers—have an important impact on the results of biomimetic affinity purification [19]. As reported previously, the final degradation products of the endo-type chitosanase are CHDS and chitotrisaccharide (CHTS), whereas that of the exo-type chitosanase is glucosamine [11]. To obtain affinity resin with optimal ligands, two types of CHOS-based ligands, CHDS-based and CHTS-based, were compared, and glucosamine was also chosen as a contrasted affinity ligand. The scheme for the synthesis protocol of CHDS-based Sepharose 6B is shown in Figure 1. The CHTS-based resin and glucosamine-based resin were synthesized from CHTS or glucosamine at the same concentration as that of CHDS (Figure 2A,B). The ninhydrin test was applied to examine the density of the free amino group (Table 1), and the linkage of cyanuric chloride to the amino groups. Purple color indicated the presence of free amino groups, and color disappearance indicated that cyanuric chloride had been linked to the amino groups. Through the change of purple color, almost all of the free amino groups linked to the cyanuric chloride. A ninhydrin test was also used to determine the coupling efficiencies and yields for CHDS, which showed an extra free amino group. About 16.8 μmol/ml free amino group was determined by ninhydrin test. The yields of the final affinity product were about 80.3%.

**Figure 1.** Synthesis protocol and scheme of the CHDS ligand coupled with active Sepharose 6B via cyanuric chloride spacer. Reagents and conditions: (**a**) epichlorohydrin, DMSO, NaOH aqueous solution, 2.5 h; (**b**) 35% saturated ammonia, overnight; (**c**) cyanuric chloride, 50% acetone, pH 7–8; (**d**), CHDS, sodium carbonate, 24 h.

**Table 1.** Ligand densities, desorption constant (*K*d) and theoretical maximum absorption (*Q*max) analysis of the affinity media.

a CHTS represents chitosan trisaccharides; b CHDS represents chitosan disaccharides.

In this study, the typical GH family 46 chitosanase, CsnOU01, was chosen as the target protein in the determination of equilibrium adsorption of different affinity resins (Figure 3). The densities of free amino groups were determined by the ninhydrin test before the addition of the affinity ligand, giving equal ligand densities (Table 1). To find the optimal affinity ligand, control resins were synthesized from CHTS or glucosamine according to the method described above (Figure 2A,B). Equilibrium adsorption studies were performed to characterize the affinity value of CsnOU01 and these three affinity media (Figure 3A). The adsorption constant for CHDS-based resin was 16.4 μg/mL, which was notably lower than that for CHTS-based resin (20.7 μg/mL) and glucosamine-based resin (88.5 μg/mL). Additionally, the theoretical maximum absorption (*Q*max) for the CHDS-based resin was significantly higher than that for other two types of resins (Table 1), indicating that the affinity of CHDS-based resin is high. Therefore, CHDS was chosen as the affinity ligand for further design and synthesis of affinity resins.

**Figure 2.** Schemes of four Sepharose 6B resins with different ligand and spacer. (**A**) Glucosamine ligand via cyanuric chloride spacer. (**B**) CHTS ligand via cyanuric chloride spacer. (**C**) CHDS ligand via 5-atom spacer arm. (**D**) CHDS ligand via 10-atom spacer arm.

To find the optimal spacer arm length, cyclic arm (cyanuric chloride) and linear arms (5-atom length and 10-atom length) were compared. Cyanuric chloride (2,4,6-trichloro-1,3,5-triazine) is a compound containing *s*-triazine (C3N3) ring, which can exert higher strength for ligand stabilization; it is widely used in the synthesis of affinity resin [23]. Figure 2C,D showed the corresponding scheme for the synthesis of resins, with spacers of 5-atom and 10-atom lengths, are shown in Figure 2C,D. According to the adsorption analysis (Figure 3B), CHDS ligand with cyclic spacer arm exhibited the highest desorption value (*K*d, 16.4 μg/mL; *Q*max, 30.9 mg/g), with an epoxy content (20.9 μmol/mL) lower than the content of 5-atom linear spacer and 10-atom linear spacer (Table 1). Therefore, cyanuric chloride was chosen as the optimal spacer arm. These observations indicate that in addition to CHDS ligand, the cyanuric chloride spacer arm is also important for the binding to chitosanase. Thus, in the larger scale of resin synthesis and chitosanases purification, CHDS was used as a ligand to couple with Sepharose 6B affinity resin through a spacer arm cyanuric chloride.

**Figure 3.** Adsorption analyses of GH family 46 enzyme CsnOU01. (**A**) Adsorption analysis of affinity resins with different ligands via cyanuric chloride as a spacer arm. (**B**) Adsorption analysis of affinity resins with CHDS as affinity ligand via different spacer arms. (**1**) Equilibrium adsorption of enzyme and affinity resin. (**2**) Plot describing the equilibrium of the absorption on the resin and the enzyme concentration in the liquid phase.

### *2.2. Affinity Purification of Chitosanases from Different GH Families*

Three chitosanases (CsnOU01, Csn, and ChoA) from GH families 46, 75, and 80, respectively, were expressed in *E. coli* BL21(DE3) through pET-22b(+) system, with or without 6×His tag. After centrifugation at 12,000 rpm for 10 min, the supernatant containing strains without 6×His tag was loaded onto a 10 mL pre-equilibrated column and then washed with washing buffer (0.1 M Tris-HCl buffer, pH 8.0) until the eluate exhibited no detectable absorbance at 280 nm. Thereafter, the enzymes were purified by the established one-step purification using CHDS-based Sepharose 6B resin.

We tested different loading and elution conditions to optimize the yield of chitosanases (Supplementary Table S1). Chitosanases are stable at a pH range of 4.0–8.0, and *Q*max values are usually determined at pH 8.0 with Tris-HCl buffer; therefore, 0.1 M Tris-HCl, pH 8.0 was used as the loading buffer. In previous elution process, non-target proteins were depleted by 0.1 M Tris-HCl, pH 8.0 containing 100 mM NaCl, in which the target protein was not eluted. In optimization of elution pH, elution buffers containing acetic acid buffers with different pH, ranging from 4.0–6.0, were used in the elution of chitosanases, and the results were compared (low pH buffers are known to favor the disruption of H-bond between chitosanases and affinity-based resin, especially for the substrate analogue-based resin). The highest protein yield was obtained at pH 5.4; 0.1 M acetic acid buffer, pH 5.4 was thus chosen as the elution buffer. In addition, the elution buffer was supplemented with 0.8 M NaCl to further deteriorate the affinity between the enzyme and the resin.

The established one-step purification method took a total time of as low as 10 min at the flow rate of 3 mL/min. With this simple and efficient affinity chromatography, CsnOU01 was purified with purities of ~98 and 98.7% according to SDS-PAGE (Figure 4(A-1)) and HPLC analysis (Figure 4(B-1)), respectively. The purification yielded CsnOU01 of 5.4 folds with the specific activity of 356.8 U/mg, and the molecular mass of the purified CsnOU01 was determined to be ~28 kDa, which was in good agreement with the theoretical molecular mass [24,25]. The bioactivity yield as a result of this affinity purification method was about 64.1% (Table 2). To determine whether or not the synthesized affinity resin has affinity for chitosanases from other GH families, Csn from GH family 75 [26] and ChoA from GH family 80 [13] were purified using the synthesized resin. As shown in Table 2, CHDS-based resin could efficiently purify the two chitosanases, with bioactivity recoveries of 45.2% and 40.8% for Csn and ChoA, respectively. The analysis by SDS-PAGE (Figure 4(A-2,A-3)) and HPLC using size-exclusion chromatography (Figure 4(B-2,B-3)) showed that both enzymes had purities of more than 95%.

**Figure 4.** Purity analysis of purified chitosanases. (**A**) SDS-PAGE analysis of purified enzymes. *Lane M*, molecular mass standard protein marker. (**A-1**) the purified CsnOU01. (**A-2**) the purified Csn. (**A-3**) the purified ChoA. (**B**) HPLC analysis of the purified CsnOU01 (**1**), Csn (**2**), and ChoA (**3**) on a TSK 3000 SW column.

The traditional purification protocol towards CsnOU01, Csn, and ChoA was developed and shown in Supplementary Table S2. Here, we compared CHDS-based affinity protocol with the traditional methods, reporting in Table 2 all the different purification steps, activity yields, and specific activities of pure enzyme. The traditional protocol with multiple steps is expensive and leads to low recoveries. The specific activity of enzymes purified by the CHDS-based protocol and the traditional

purification protocol is similar. However, the purity of CHDS-based affinity purification is higher than the traditional methods.

As a contrast, Ni-NTA Sepharose 6B resin was also used to purify the three recombinant chitosanases containing 6×His-tag, by immobilized metal affinity chromatography (IMAC). Even if the IMAC protocol led to an activity recovery higher than the CHDS-based affinity protocol, the specific activities are lower (Table 2). Because of all the obvious advantages of the CHDS-based affinity protocol, including one-step chromatography, no use of toxic imidazole, higher purity, and shorter times, this approach has the potential to be used for industrial applications of high purity chitosanase.

**Table 2.** Comparison of traditional, CHDS-based, and immobilized metal affinity chromatography (IMAC)affinity purification methods for three different chitosanases.

a In the CHDS-based affinity purification protocol, enzymes without 6× his-tag were purified by CHDS-based medium; b in the Ni-NTA affinity purification protocol, enzymes with 6×his-tag were purified by Ni-NTA medium; c in the traditional protocol, CsnOU01 without 6×his-tag was purified by five steps, including ultrafiltration, ammonium sulfate precipitation, desalting, anion-exchange, and gel-filtration chromatography; d the traditional purification protocol of Csn was composed of three steps, including ammonium sulfate precipitation, desalting, and anion-exchange chromatography; e the traditional purification protocol of ChoA was composed of six steps, including ammonium sulfate precipitation, hydrophobic chromatography, desalting, anion-exchange chromatography, and two steps of gel-filtration chromatography.


*3.1. Structural Properties and Catalytic Performance of Ni Supported on CeO2 Solids*

*3.1. Structural Properties and Catalytic Performance of Ni Supported on CeO2 Solids*  The 5 wt% Ni supported on CeO2 carriers prepared by different preparation methods exhibited largely different catalytic activity under DRM (20 vol% CO2/20 vol% CH4/He, 750 °C) (Figure 2) and structural and morphological differences were apparent among them. The high conversions achieved The 5 wt% Ni supported on CeO2 carriers prepared by different preparation methods exhibited largely different catalytic activity under DRM (20 vol% CO2/20 vol% CH4/He, 750 ◦C) (Figure 2) and structural and morphological differences were apparent among them. The high conversions achieved

in our work, are close to the calculated equilibrium values for the used feed gas composition at 1 atm total pressure [52]. The 5 wt% Ni/CeO2-HT catalyst with the largest surface area (~ 50 m2 g−1) consisted

in our work, are close to the calculated equilibrium values for the used feed gas composition at 1 atm total pressure [52]. The 5 wt% Ni/CeO2-HT catalyst with the largest surface area (~50 m2 g −1 ) consisted of smaller ceria mean primary crystallite size (~11.5 nm), smaller Ni mean particle size (~8.4 nm), and 11.5% Ni dispersion (Table S1, Figure 9). On the other hand, the 5 wt% Ni/CeO2-SG with smaller surface area (~14.5 m2 g −1 ), consisted of larger ceria primary crystallite size (~43.1 nm) and Ni mean particle size (~20.8 nm; Ni dispersion 4.7%). The latter results are in good agreement with the literature [17,19,20,44,46,53–56]. The structural heterogeneity of the CeO2 surface had strong effect on the deposition of Ni species. In fact, it was reported [45] that NiO (10 wt%) deposited on ceria nanoparticles of cubic shape was homogeneously dispersed. Yahi et al. [43] used three different preparation methods (microemulsion, sol-gel, and autocombustion) to synthesize CeO2, on which 15 wt% of Ni was deposited. They clearly showed, via XRD and TPR studies, that NiO could be present with good crystallization in different phases (i.e., monoclinic and cubic phase for the auto-combustion and sol-gel, and cubic only phase for the microemulsion), which depended on the different preparation method of the ceria support. The authors [43] also reported different pore volume, surface area, and particle size by changing the preparation method, results of which are in good agreement with the present work. Xu et al. [55] prepared three Ni/Al2O3 catalytic systems of the same nominal composition by varying the preparation method, namely: Impregnation, water-in-oil-microemulsion, and sol-gel. By using XRD, TEM, and TPR, they showed crystalline structural differences, both for the support and Ni, which led to similar catalytic performance, but differences in the coking resistant, and thus in catalyst stability, as seen also in the present work. They argued that the latter differences might be due to strong metal–support interactions leading to differences on Ni particles size and dispersion. The latter results are in good agreement with those reported by other research groups [44,45,57], where a non-conventional synthesis method, namely the precipitation ionic exchange, led to cubic phases of CeO2 and NiO (verified via FEG-SEM and XRD). In a recent study, Lykaki et al. [28] showed that the hydrothermal method (among other research works which are well reported there-in) led to well defined ceria nanorods of high specific surface area and with improved redox properties. *Catalysts* **2019**, *9*, x FOR PEER REVIEW 13 of 24 A possible explanation on the above results regarding carbon deposition on Ni/CeO2 as influenced differently by the DRM, CO/He, and CH4/He reaction conditions seems to be the competition of CH4 and CO for the same Ni catalytic active sites, even though under DRM higher energy barriers are needed during the first and second steps of CH4 dissociation (CH4 → CH3 + H and CH3 → CH2 + H), and carbon dimer formation (C2, carbon dimer is the first crucial step for inactive carbon formation). It was reported that both CH4 and CO preferentially dissociate on Ni(111) surface, with the former to also favorably dissociate on Ni(100) and Ni(110) surfaces to a similar extent [66– 74]. The main focus of this work was the effect of preparation method of CeO2 used as support of Ni (5 wt% Ni/CeO2) on the carbon deposition rates of the main routes (CH4 decomposition and reverse Boudouard reaction), and on carbon removal rate (participation of support's OL). It was shown that the preparation method influenced the Ni particle size and its morphology, and in turn its surface electronic structure, thus its catalytic performance for the DRM reaction at 750 °C. The various temperature-programmed and step-gas concentration transient experiments (including the use of isotopes) provided important information for the better understanding of the carbon pathways during DRM, to be discussed next.

**Figure 9.** Comparative graph of the crystallite size (dCeO2 and dNi, nm) and amount of carbon deposition (mg C g−1) after 12 h in DRM as a function of ceria support synthesis method. **Figure 9.** Comparative graph of the crystallite size (dCeO2 and dNi, nm) and amount of carbon deposition (mg C g−1 ) after 12 h in DRM as a function of ceria support synthesis method.

*3.2. Rates of Carbon Deposition and Removal under DRM Reaction Conditions*  As mentioned in the Introduction section, supported Ni catalysts suffer from large amounts of carbon deposition under DRM reaction conditions. The amount of carbon deposited over the catalytic surface should be considered as the net rate between carbon formation (CH4 decomposition and Boudouard reaction) and the carbon removal (e.g., participation of support's lattice oxygen). The carbon removal rate via the participation of lattice oxygen was probed by the transient response curves depicted in Figure 8B after partially exchanging active ceria support lattice 16OL with 18OL. The carbon removal rate by this chemical step can be written to a first approximation as shown by the following Equation (1): The H2-TPD traces (Figure 1) obtained over the four catalytic systems suggest large differences in the electronic structure of the Ni supported metal surfaces (distribution of binding strength between H and surface Ni atoms (ENi-H, kcal mol−1 )). The electronic structure of Ni surface (different faces and defects), as well shown in the literature, influenced the rates of carbon formation and diffusion on the Ni surface and towards the support during both CH4 decomposition and Boudouard reaction [58–65]. The morphological differences presented in the CeO2 carrier through SEM images (Figure S3) seem to play a role for the induced differences in the electronic structure of the Ni surface (Figure 1), as reported also in previous publications [27,46]. HR-TEM (Figure S2) also suggested different morphologies for the Ni nanoparticles for the given Ni/CeO2-HT catalyst, where ceria preparation method also influenced the mean Ni particle size as illustrated in Figure 9. The amount of carbon measured after

For reaction step (2), s is a catalytic site at the metal-support interface, the support or both, and

where k is an effective rate constant for the reaction step (2), θOL is the surface coverage of support lattice oxygen able to participate in reaction step (2), and θC is the surface coverage of carbon formed

of carbon, whilst θOL (t) is also determined by the rate of surface OL diffusion towards carbon. These two important kinetic parameters describing the rate of carbon gasification via Eq. (1) are likely to

depend on the Ni particle size/morphology as well as CeO2 primary particle size.

VO is a surface oxygen vacancy of ceria support.

RC18O (t) = k θOL(t) θC(t) (1)

C-s + 18O-L → C18O(g) + s + Vo (2)

12 h of DRM (Figure 9, Table S5), and the transient results of CH4 and CO decomposition reactions (Figures 5–8), tend therefore to suggest that the different morphology of ceria, as the result of different preparation method applied, induced Ni morphological/surface structural differences, thus surface nickel electronic modifications. These in turn govern the DRM activity behavior and carbon deposition rate of the various ceria-supported Ni catalysts [58].

Based on the CH4-activity results reported in Figure 2 and the Ni dispersion values over the same catalysts (Table S1), it appears that Ni/CeO2-HT contained a smaller number of active sites than Ni/CeO2-SG catalyst. On the other hand, the former catalyst produced more carbon (larger carbon accumulation rates) under DRM reaction conditions (Figures 3 and 9), whereas the opposite was seen under transient methane decomposition reaction conditions (Figure 5); the initial rates of CH4 dissociation to H2 and the deposited amount of carbon (Figure 5D) were higher on Ni/CeO2-HT than Ni/CeO2-SG catalysts (Table 1). As illustrated in Figure 9, there seemed to be no clear relationship between dCeO2 and dNi and the amount of carbon deposition for at least 12 h after DRM. As is discussed below, the carbon formation and removal rates during DRM cannot be influenced only by the Ni metal and ceria support particle size in a clear monotonic way. The Ni-C strength, diffusion of carbon species on the Ni surface, and oxygen diffusion from the ceria support that the Ni phase and Ni-ceria interface (where carbon is formed) should all influence carbon deposition rate [46].

A possible explanation on the above results regarding carbon deposition on Ni/CeO2 as influenced differently by the DRM, CO/He, and CH4/He reaction conditions seems to be the competition of CH4 and CO for the same Ni catalytic active sites, even though under DRM higher energy barriers are needed during the first and second steps of CH4 dissociation (CH4 → CH3 + H and CH3 → CH2 + H), and carbon dimer formation (C2, carbon dimer is the first crucial step for inactive carbon formation). It was reported that both CH4 and CO preferentially dissociate on Ni(111) surface, with the former to also favorably dissociate on Ni(100) and Ni(110) surfaces to a similar extent [66–74].

The main focus of this work was the effect of preparation method of CeO2 used as support of Ni (5 wt% Ni/CeO2) on the carbon deposition rates of the main routes (CH4 decomposition and reverse Boudouard reaction), and on carbon removal rate (participation of support's OL). It was shown that the preparation method influenced the Ni particle size and its morphology, and in turn its surface electronic structure, thus its catalytic performance for the DRM reaction at 750 ◦C. The various temperature-programmed and step-gas concentration transient experiments (including the use of isotopes) provided important information for the better understanding of the carbon pathways during DRM, to be discussed next.

#### *3.2. Rates of Carbon Deposition and Removal under DRM Reaction Conditions*

As mentioned in the Introduction section, supported Ni catalysts suffer from large amounts of carbon deposition under DRM reaction conditions. The amount of carbon deposited over the catalytic surface should be considered as the net rate between carbon formation (CH4 decomposition and Boudouard reaction) and the carbon removal (e.g., participation of support's lattice oxygen). The carbon removal rate via the participation of lattice oxygen was probed by the transient response curves depicted in Figure 8B after partially exchanging active ceria support lattice 16OL with 18OL. The carbon removal rate by this chemical step can be written to a first approximation as shown by the following Equation (1):

$$\mathbf{R\_{C18O}}\ (\mathbf{t}) = \mathbf{k}\ \boldsymbol{\theta}\_{\text{OL}}\ (\mathbf{t})\ \boldsymbol{\theta}\_{\text{C}}\ (\mathbf{t})\tag{1}$$

where k is an effective rate constant for the reaction step (2), θOL is the surface coverage of support lattice oxygen able to participate in reaction step (2), and θC is the surface coverage of carbon formed during DRM. In Equation (1), k might be considered as an average reactivity of more than one kind of carbon, whilst θOL (t) is also determined by the rate of surface OL diffusion towards carbon. These two important kinetic parameters describing the rate of carbon gasification via Equation (1) are likely to depend on the Ni particle size/morphology as well as CeO2 primary particle size.

$$\rm{C-s} + \rm{^{18}O-}\_{\rm{L}} \rightarrow \rm{C}^{18}O(g) + s + \rm{Vo} \tag{2}$$

For reaction step (2), s is a catalytic site at the metal-support interface, the support or both, and VO is a surface oxygen vacancy of ceria support.

Initial carbon formation rates (recorded over a clean catalyst surface) and total amount of carbon accumulated during 30 min treatment of the catalysts were measured by performing transient experiments at 750 ◦C with 20 vol% of CH4 reactant in the feed (Figure 5), similar to DRM conditions, and by the reverse Boudouard reaction or the CO dissociation alone (Figure 6), using 20 vol% CO (similar composition obtained in the DRM depicted in Figure 2). In addition, the individual amount of carbon derived from each route (CH4 vs. CO) when both gases were present in the feed stream was also estimated for probing any synergy effects on the accumulation of carbon (Figure 7).

It is clearly shown that both the initial rate of carbon formation (Figures 5A and 6A) and the total amount of carbon formed (Table S5) over the four catalytic surfaces was at least 10 times larger in the case of CH4 decomposition compared to the reverse Boudouard reaction. This result is in very good agreement with the TPO results obtained following the isotopic DRM reaction (13CO2/ 12CH4/He, Figure 4) and the isotopic 13CO/ 12CH4/He experiment (Figure 7), which both quantified the origin of carbon accumulation. Thus, the first conclusion is that CH4 activation route was dominant and the one controlling the rate of carbon formation, however, the competition of CH4 and CO activation for same catalytic sites, as clearly demonstrated, should be highly considered. In particular, the Ni/CeO2-HT catalyst (CeO2 prepared by the hydrothermal method) led to a smaller (~1.8 times) initial rate of carbon formation via CH4 decomposition (Figure 5A) and CO dissociation (~3.5 times, Figure 6A) compared to the Ni/CeO2-TD and Ni/CeO2-PT catalysts, respectively. At this point it would be of interest to mention the effect of DRM reaction temperature on the origin of carbon deposition (CH4 vs. CO2 activation route). Vasiliades et al. [17,20] reported similar 12CH4/ 13CO2/He isotopic DRM experiments as those reported in Section 2.6.2 (Figure 4) at 550 and 750 ◦C over 5 wt% Ni/Ce1−xMxO2 (M = Zr4+, Pr3+) catalysts, the support of which (including pure CeO2) was prepared by the citrate sol-gel method. It was illustrated that at the low-T of 550 ◦C, a higher contribution to carbon deposition was obtained via the CO2 activation route (reverse Boudouard reaction: 2 CO → CO2 + C) as opposed to the reaction T of 750 ◦C.

A careful comparison could be also made on the transient rates of CO formation during the CH4/He treatment (Figure 5C), where the Ni/CeO2-HT catalyst revealed significantly larger initial rate (~1.5 times) of its labile oxygen towards carbon gasification to CO(g) compared to the Ni/CeO2-PT and Ni/CeO2-TD catalysts, and even larger (~3 times) in the case of Ni/CeO2-SG catalyst. The latter results are in a good agreement with the experimental findings shown in Figure 8B, where gasification of the formed carbon towards C18O(g) formation under DRM reaction conditions takes place by the participation of support's 18OL. The amount of available labile oxygen for 16O/ 18O isotopic exchange was found to be similar for the four supported Ni catalysts, a fact that suggests that morphological differences in their metal and support do not influence this specific process at 750 ◦C.

Considering the transient rates of C18O(g) obtained over the four catalytic systems (Figure 8B), it was apparent that Ni/CeO2-HT catalyst had activated a higher amount of lattice 18O (11.4 mmol g−1 ) by a factor of ~1.1 compared to Ni/CeO2-SG (10.2 mmol g−1 , Table S6). Given the fact that the amount of carbon accumulated during DRM after 12 h was ~1.5 times larger in the case of Ni/CeO2-HT compared to Ni/CeO2-SG (see Section 2.6.1), it might be suggested that the effective rate constant k (Equation (1)) must be considered larger in the former than the latter catalyst. This result is important since it can prove that during DRM, the rate of carbon deposition on Ni/CeO2-HT must be considered larger than on Ni/CeO2-SG, a result in harmony with the transient CH4 decomposition studies described in Section 2.6.3 (Figure 5A). Moreover, considering the integral rates of CH4 conversion reported in Figure 2A, the carbon deposited by CH4 during the 2 min transient shown in Figure 8B (end of rate of carbon removal by 18O lattice oxygen) could be estimated. Then, the ratio of the amount of carbon removed by 18O lattice oxygen as C18O (see Figure 8B, Table S6) to the amount of carbon deposited via

CH4 decomposition could be estimated. This ratio was found to follow the order: CeO2-HT > CeO2-TD > CeO2-SG > CeO2-PT. The implication of this is that the reason that Ni/CeO2-HT experienced the largest amount of carbon accumulation after 12 h in DRM (see Table S5), ~3.8 times larger than that of Ni/CeO2-PT, should not be considered to be due to its inferior ability compared to the other ceria supports to provide mobile lattice oxygen for carbon gasification, at least for the first 30 min of TOS. It was suggested that carbon deposition and removal rates could change with longer time-on-stream as Ni surface and ceria support start to accommodate carbon deposits. Thus, deep understanding of the carbon accumulation with TOS and the intrinsic reasons for this is required for the given DRM ceria-supported Ni catalytic system.

It is noteworthy to be mentioned at this point that the differences in the delays of C18O(g) that appeared during the switch from the inert gas to the DRM feed gas among the different catalysts (Figure 8B) were due to the different transient kinetics of reduction of the initially oxidized Ni surface (after 16O/ 18O exchange), as previously reported [46,75].

The temperature-programmed oxidation profiles of the carbon accumulation over a reduced metal surface after CH4 decomposition or CO disproportionation alone or in the presence of both carbon sources illustrated that the co-presence of CH4 and CO largely enhances the rate of carbon deposition.

#### **4. Materials and Methods**

#### *4.1. Catalysts Synthesis*

### 4.1.1. Cerium Dioxide (CeO2) Supports

#### Sol-Gel Method

The CeO2-SG metal oxide support was prepared using the modified citrate sol-gel method. The Ce metal precursor of Ce(NO3)3.6H2O (Sigma Aldrich, > 99% purity) was diluted in a beaker containing 100 mL solution of 1:1 (*v*/*v*) ratio of deionized H2O and propanol-1. Citric acid (CA) was added for the creation of 1:1.5 Mtot:CA, where Mtot refers to the total molar concentration of metal ions in the solution, and similarly, the CA (molar concentration of citric acid). The pH of the solution was continuously adjusted (pH ~2.0) by adding HNO3 (5M), with the solution to be under stirring at 70 ◦C. The resulting gel-like yellowish material was dried at 120 ◦C for 12 h, prior to its thermal heating with 1 ◦C min−1 under static air from room T to 500 ◦C. The sample was then kept at 500 ◦C for 6 h and its temperature was further increased to 750 ◦C (β = 5 ◦C min−1 ) and kept for additional 4 h before cooled down to room T.

#### Thermal Decomposition Method

The CeO2-TD metal oxide support was prepared using the thermal decomposition method. An appropriate amount of Ce(NO3)3.6H2O was dried in static air at 120 ◦C for 12 h, and after being cooled down to room T, its temperature was increased with 1 ◦C min−1 to 500 ◦C, where it was kept for 6 h. The temperature of the resulting material was then further increased to 750 ◦C (β = 5 ◦C min−1 ), where it was kept for additional 4 h before cooled down to room T.

#### Hydrothermal Method

The CeO2-HT metal oxide support was prepared using the hydrothermal method. During this method, 40 M NaOH (pH ~12.5) and 0.13 M Ce(NO3)3·6H2O aqueous solutions were mixed (75 mL:175 mL), under vigorous stirring until a purplish milky slurry was formed. The milky slurry with total volume of 250 mL was kept under continuous stirring for 1 h and then transferred in a 1 L Teflon bottle and heated for 48 h at 90 ◦C. The reaction product was then cooled down to room temperature and the solid product was collected by filtration. The collected solid was rinsed with deionized water until pH neutralization to remove any co-precipitate salts. Drying and calcination procedures were performed as described in the thermal decomposition method.

#### Precipitation Method

The CeO2-PT metal oxide support was prepared using the precipitation method. In the latter method, ammonia solution (25% *v*/*v*) as precipitation agent was added dropwise at room temperature and under continuous stirring in a 0.5 M aqueous solution of Ce(NO3)3·6H2O until pH reached the value of 10, conditions that were controlled for 3 h. The resulting solution was then filtered, and the precipitate material was dried and calcined as described in the thermal decomposition method.

### 4.1.2. Wetness Impregnation of CeO2 Supports with Ni (5 wt% Ni/CeO2)

The resulting CeO2 supports from the various synthesis procedures were grinded prior to Ni metal deposition. A given amount of each of the oxidic ceria support was diluted in an aqueous solution of Ni(NO3)2·6H2O (Sigma-Aldrich, >99% purity) so as to be impregnated with 5 wt% Ni nominal loading. The resulting slurry was dried overnight at 120 ◦C, followed by cooling to room T. The temperature of the solid was then increased under static air to 750 ◦C, where it was kept for 4 h. The resulting material was named "fresh catalyst", and prior to any catalytic measurements it was in situ reduced in pure H2 gas (1 bar, 50 NmL min−1 ) at 700 ◦C for 2 h.

#### *4.2. Catalysts Characterization*

#### 4.2.1. Powder X-ray Diffraction (XRD)

Powder X-ray diffractograms of the calcined CeO2-supported Ni catalysts were recorded by using a Shimadzu 6000 Series diffractometer (CuKa radiation, λ = 0.15418 nm, Kyoto, Japan) in the 20–80◦ 2θ range (2◦ min−1 , 0.02◦ increment). By using the Scherrer equation [17], the lattice parameter (α, Å), the mean primary crystallite size (dc, nm) of the ceria pseudo-cubic structure, and the mean crystal size of NiO were estimated. The latter was used to estimate the Ni mean particle size (dNi, nm) as of Equation (3), after the assumption that Ni and NiO preserve the same particle geometrical shape:

$$\text{d (Ni, nm)} = \text{d (NiO, nm)} \times 0.847.\tag{3}$$

#### 4.2.2. Surface Texture (BET/BJH)

The BET specific surface area (SSA, m2 g −1 ), the total pore volume (Vp, cm3 g −1 ), and the mean pore size (dp, nm) of the CeO2-supported nickel catalysts and their supports alone were determined based on N2 adsorption/desorption isotherms measured at 77 K with a Micromeritics Gemini 2360 surface area and pore size analyzer (Norcross, Georgia, United States). Prior to any measurements, the sample was degassed in N2 gas flow at 300 ◦C for 4 h.


**9. Knowledge, attitude and practice of family planning**

The dividends accrued from improvements in reproductive health are cumulative and key to achieving sustainable development goals (SDGs) by improving maternal health, reducing child mortality and eradicating extreme poverty. Family planning brings transformational benefits to the women, families, communities and nations [16]. In the twenty-first century, the maternal mortality in the continent is still unacceptably high. The lifetime risk of maternal mortality of women in SSA is 1 in 39 live births, the highest when compared to other regions.

Despite recent increases in contraceptive use, sub-Saharan Africa is still characterized by high levels of fertility with TFR of 5 (number of births per woman) and a considerable unmet need for contraception [76]. Sub-Saharan Africa is still undergoing demographic transition (i.e. a shift to low death rate and birth rates). This is largely due to high birth rates with low contraceptive use. It is estimated that 90% of abortion-related and 20% of pregnancy-related morbidity and mortality together with 32% maternal deaths could be prevented by the use of effective contraceptive [9, 77]. In SSA, about 14 million unintended pregnancies occur each year, with about half occurring among women aged 15–24 years [78, 79]. The low level of utilization of contraceptives is due to several factors, the health systems and the framework within which family planning (FP) services are delivered, and suboptimal service factors [79]. Others are barriers at the individual level: risk perception, lack of or insufficient knowledge needed to make desired decision or choices, male partner disapproval and economic and geographic access to service facility. Knowledge of FP is crucial to make informed choice. Also noted are barriers to utilization of FP: commodity stock-out, limited provider skills and limited number of methods [80]. Even though contraceptive methods and services are frequently geared towards women, men are the primary decision-makers on family size and their partners' use of family planning methods [8, 81, 82].

Men's fertility preferences and attitudes towards family planning seem to influence their wives' attitudes towards the use of modern contraceptives [83]. This translates to the fact that the importance of male involvement in any family planning programme cannot be overemphasized. Information and knowledge on contraceptive methods are necessary tools to informed choices and utilization. Better informed and knowledgeable women are able to seek for desired information and also know where to access appropriate services. On the other hand, lack of knowledge together with cultural, social and religious factors is a major impediment to service utilization [81, 84, 85].

At the community level, since individuals leave in communities, it definitely can influence personal health-seeking behavior, as there are intersections between personal beliefs and attitudes and community norms. Previous studies revealed that women may choose to accept family planning or indeed choose a particular method because of the methods adopted by those in the community [86]. Again, recently, several studies have explored the role of contextual factors in contraceptive use in African countries [87–90]. Beyond individual and family factors, the context in which women live does influence their contraceptive decisions. The growing body of literature has identified a number of contextual factors that influence the use of contraceptive: presence and quality of reproductive health services, macroeconomic factors, community fertility norms, female autonomy and availability of physical infrastructure [91]. Previous studies [26, 76, 92] and reports of Demographic and Health Surveys [61] in SSA reported a near universal knowledge on family planning among women of reproductive age group. Unfortunately, this has not translated into increased utilization of contraceptive methods as evidenced by low contraceptive prevalence rates (CPRs). This can well be demonstrated by contraceptive prevalence in the world and by region of Africa (**Figure 2**) [93] with West Africa having the lowest prevalence rate among married or in-union women (15–49 years old) in 2015.

**10. Unmet needs for family planning**

17

Western Africa

Southern Africa

Northern Africa

Middle Africa

Eastern Africa

Africa

World

Sub-Saharan africa

Least developed countries

23

28

33

The decline in fertility in SSA has been slow than expected and has stalled in some countries [94, 95]. The total fertility rate varies from 4.8 children per woman in Kenya to 7.6 in the Republic of Niger [8, 9] and the lowest contraceptive prevalence of 22% among married women [96] and globally the highest level of unmet need for FP of about 25% [96]. Worldwide, over 222 million women have unmet need for contraceptive [97], and about 34 million women in Africa had unmet need for FP in 2009 [98]. The demand for contraceptives, with improved access and uptake, is the key public health intervention to improve maternal health outcomes, thereby reducing maternal mortality. Increasing contraceptive use has many demographic dividends, and unmet need denies women these benefits and violates their reproductive health rights. Studies have shown that several obstacles have hindered women access to FP services: unavailability of services, cultural and religious barriers, lack of knowledge and rural residence [99, 100]. Additionally, weaknesses in the existing FP programmes coupled with the fact that in SSA FP programmes tended to offer select methods (as a matter of convenience) or as a means of promoting the most effective and long-lasting methods [78]. Reasons for not

64

26

Contraceptive use Unmet need

24

22

13

12

83

15

24

22

Family Planning Services in Africa: The Successes and Challenges

http://dx.doi.org/10.5772/intechopen.72224

24

64

53

40

**Figure 2.** Contraceptive prevalence and unmet need for FP (percent) in the world and African region.

40

The low usage and CPRs could be attributed to negative attitude directed at the methods and other factors discussed earlier. Thus, the promotion of modern contraceptive use will require multifaceted interventions across all the levels of society. Specifically, addressing some or all of these barriers to the use of modern FP will importantly contribute to family, community and national socio-economic development. Particularly, contraceptive use needs to be promoted in West Africa on both health and economic grounds.

**Figure 2.** Contraceptive prevalence and unmet need for FP (percent) in the world and African region.

### **10. Unmet needs for family planning**

unintended pregnancies occur each year, with about half occurring among women aged 15–24 years [78, 79]. The low level of utilization of contraceptives is due to several factors, the health systems and the framework within which family planning (FP) services are delivered, and suboptimal service factors [79]. Others are barriers at the individual level: risk perception, lack of or insufficient knowledge needed to make desired decision or choices, male partner disapproval and economic and geographic access to service facility. Knowledge of FP is crucial to make informed choice. Also noted are barriers to utilization of FP: commodity stock-out, limited provider skills and limited number of methods [80]. Even though contraceptive methods and services are frequently geared towards women, men are the primary decision-makers on family size and their partners' use of family

Men's fertility preferences and attitudes towards family planning seem to influence their wives' attitudes towards the use of modern contraceptives [83]. This translates to the fact that the importance of male involvement in any family planning programme cannot be overemphasized. Information and knowledge on contraceptive methods are necessary tools to informed choices and utilization. Better informed and knowledgeable women are able to seek for desired information and also know where to access appropriate services. On the other hand, lack of knowledge together with cultural, social and religious factors is a major impedi-

At the community level, since individuals leave in communities, it definitely can influence personal health-seeking behavior, as there are intersections between personal beliefs and attitudes and community norms. Previous studies revealed that women may choose to accept family planning or indeed choose a particular method because of the methods adopted by those in the community [86]. Again, recently, several studies have explored the role of contextual factors in contraceptive use in African countries [87–90]. Beyond individual and family factors, the context in which women live does influence their contraceptive decisions. The growing body of literature has identified a number of contextual factors that influence the use of contraceptive: presence and quality of reproductive health services, macroeconomic factors, community fertility norms, female autonomy and availability of physical infrastructure [91]. Previous studies [26, 76, 92] and reports of Demographic and Health Surveys [61] in SSA reported a near universal knowledge on family planning among women of reproductive age group. Unfortunately, this has not translated into increased utilization of contraceptive methods as evidenced by low contraceptive prevalence rates (CPRs). This can well be demonstrated by contraceptive prevalence in the world and by region of Africa (**Figure 2**) [93] with West Africa having the lowest prevalence rate among married or in-union women

The low usage and CPRs could be attributed to negative attitude directed at the methods and other factors discussed earlier. Thus, the promotion of modern contraceptive use will require multifaceted interventions across all the levels of society. Specifically, addressing some or all of these barriers to the use of modern FP will importantly contribute to family, community and national socio-economic development. Particularly, contraceptive use needs to be pro-

moted in West Africa on both health and economic grounds.

planning methods [8, 81, 82].

82 Family Planning

ment to service utilization [81, 84, 85].

(15–49 years old) in 2015.

The decline in fertility in SSA has been slow than expected and has stalled in some countries [94, 95]. The total fertility rate varies from 4.8 children per woman in Kenya to 7.6 in the Republic of Niger [8, 9] and the lowest contraceptive prevalence of 22% among married women [96] and globally the highest level of unmet need for FP of about 25% [96]. Worldwide, over 222 million women have unmet need for contraceptive [97], and about 34 million women in Africa had unmet need for FP in 2009 [98]. The demand for contraceptives, with improved access and uptake, is the key public health intervention to improve maternal health outcomes, thereby reducing maternal mortality. Increasing contraceptive use has many demographic dividends, and unmet need denies women these benefits and violates their reproductive health rights. Studies have shown that several obstacles have hindered women access to FP services: unavailability of services, cultural and religious barriers, lack of knowledge and rural residence [99, 100]. Additionally, weaknesses in the existing FP programmes coupled with the fact that in SSA FP programmes tended to offer select methods (as a matter of convenience) or as a means of promoting the most effective and long-lasting methods [78]. Reasons for not using contraceptive are quite unfounded as contraception is a safe medical intervention. It is estimated that mortality risk of unplanned and unwanted pregnancy is 20 times the risk of any modern contraceptive method and 10 times the risk of a "properly" performed abortion [101].

The concept of unmet needs for contraceptive dates back to the 1960s, the "KAP-Gap" era, and was used as a rationale for investment in family planning programmes [102]. It is the proportion of currently married, fecund women who do not want any more children but are not using any form of family planning (unmet need for limiting) or currently married women who want to postpone their next birth for 2 years but are not using any form of family planning (unmet need for spacing) [103]. Unmet need is essentially a conflict between what a woman wants and what she does about it. She might want fewer fertility but fails to take action needed to prevent pregnancy. The total demand for family planning is the proportion of married women with unmet need and married women with met need for family planning. In other words, it is the sum of contraceptive prevalence plus unmet need for family planning. Currently, the total demand for FP (sum of unmet need and current contraceptive use) is around 44% in SSA [104]. Also, unique to the continent is the fact that predominantly the unmet need is for spacing rather than for limiting births. Thus, it shows the importance attached to child spacing in Africa and a reluctance to commit to a final cessation of childbearing [9]. It also shows that demand for contraception (to space) exists within this population that can be explored. In countries where growing numbers of women want to avoid a pregnancy but contraceptive use is low, unmet need is higher. Rwanda, Senegal, Togo and Uganda all have unmet need of about 30% or higher [104]. The main objective for the study of unmet need is to estimate the potential demand for FP [102].

Basically, its purpose is to identify women who are currently exposed to the risk of unintended pregnancy but who are not using any method of contraceptive. In theory, these women either do not want any more births (limiting) or want to postpone the next birth for at least 2 more years (spacing). The computation of unmet need is complex and can vary depending on which categories of women are included in the definition [104]. When this is summed up with current contraceptive use, it provides a picture of total potential demand for FP in a country (**Figure 3**).

as a user of natural methods. Currently, in the DHS questionnaire, there is no follow-up questions specific to natural methods resulting in possibility of under reporting in some developing countries [106]. Despite these drawbacks, measurement of unmet need has endured as a good analytical tool till date. Its importance cannot be overemphasized: the estimate is useful as it helps to reveal the size and characteristics of the potential market for contraceptives, allows for projection of how much fertility could decline if additional needs for FP were met. Reducing unmet need for FP is key to helping couples achieve their reproductive rights and achieving demographic goals. The lessons here are to understand the variations in unmet need across the continent. Respective national governments will need to understand uniqueness of unmet needs in order to strengthen family planning programmes to reduce unmet need. Studies have revealed that strong programmatic interventions not only reduce unmet need and increase contraceptive

58

28

Using contraception Not using contraception (unmet need)

30

30

35

17

85

19

13

http://dx.doi.org/10.5772/intechopen.72224

Family Planning Services in Africa: The Successes and Challenges

53

26

16

54

use but also increase the proportion of women using modern contraceptives [107].

The challenges to family planning programmes are many, varied and require attention at the highest policy level in order to realize the huge demographic, socio-economic and development

**11. Challenges**

12

15

10

**Figure 3.** Potential demand for family planning.

15

22

31

23

4

Burkina Faso

Cote d'Ivoire

Chad

Ghana

Nigeria

Kenya

Malawi

Rwanda

Uganda

Zimbabwe

Experts have also raised the following concerns on its measurement:

Today, the major source of data for measuring unmet need globally is the Demographic and Health Surveys (DHS) and for which data is available in most countries in SSA. Many countries have had two or four rounds of such surveys between 1990 and 2014. The DHS questions administered to women asked whether they are doing anything to avoid a pregnancy. If the woman reports the use of a natural method and does not simultaneously use a more effective method, she is counted

**Figure 3.** Potential demand for family planning.

using contraceptive are quite unfounded as contraception is a safe medical intervention. It is estimated that mortality risk of unplanned and unwanted pregnancy is 20 times the risk of any modern contraceptive method and 10 times the risk of a "properly" performed abortion [101]. The concept of unmet needs for contraceptive dates back to the 1960s, the "KAP-Gap" era, and was used as a rationale for investment in family planning programmes [102]. It is the proportion of currently married, fecund women who do not want any more children but are not using any form of family planning (unmet need for limiting) or currently married women who want to postpone their next birth for 2 years but are not using any form of family planning (unmet need for spacing) [103]. Unmet need is essentially a conflict between what a woman wants and what she does about it. She might want fewer fertility but fails to take action needed to prevent pregnancy. The total demand for family planning is the proportion of married women with unmet need and married women with met need for family planning. In other words, it is the sum of contraceptive prevalence plus unmet need for family planning. Currently, the total demand for FP (sum of unmet need and current contraceptive use) is around 44% in SSA [104]. Also, unique to the continent is the fact that predominantly the unmet need is for spacing rather than for limiting births. Thus, it shows the importance attached to child spacing in Africa and a reluctance to commit to a final cessation of childbearing [9]. It also shows that demand for contraception (to space) exists within this population that can be explored. In countries where growing numbers of women want to avoid a pregnancy but contraceptive use is low, unmet need is higher. Rwanda, Senegal, Togo and Uganda all have unmet need of about 30% or higher [104]. The main objective for the study of unmet need is to estimate the potential demand for FP [102].

Basically, its purpose is to identify women who are currently exposed to the risk of unintended pregnancy but who are not using any method of contraceptive. In theory, these women either do not want any more births (limiting) or want to postpone the next birth for at least 2 more years (spacing). The computation of unmet need is complex and can vary depending on which categories of women are included in the definition [104]. When this is summed up with current contraceptive use, it provides a picture of total potential demand for FP in a country (**Figure 3**).

Experts have also raised the following concerns on its measurement:

• Women's personal opposition to family planning.

not and thus not at risk of pregnancy [105].

methodological issue.

84 Family Planning

• The term does not necessarily reflect actual or potential interest in method use.

• It does not reflect how women perceive themselves to be at risk of pregnancy.

• Failure to differentiate between married women who are sexually active and those who are

• Underreporting of natural methods [106] in large-scale surveys which is a long standing

Today, the major source of data for measuring unmet need globally is the Demographic and Health Surveys (DHS) and for which data is available in most countries in SSA. Many countries have had two or four rounds of such surveys between 1990 and 2014. The DHS questions administered to women asked whether they are doing anything to avoid a pregnancy. If the woman reports the use of a natural method and does not simultaneously use a more effective method, she is counted as a user of natural methods. Currently, in the DHS questionnaire, there is no follow-up questions specific to natural methods resulting in possibility of under reporting in some developing countries [106]. Despite these drawbacks, measurement of unmet need has endured as a good analytical tool till date. Its importance cannot be overemphasized: the estimate is useful as it helps to reveal the size and characteristics of the potential market for contraceptives, allows for projection of how much fertility could decline if additional needs for FP were met. Reducing unmet need for FP is key to helping couples achieve their reproductive rights and achieving demographic goals.

The lessons here are to understand the variations in unmet need across the continent. Respective national governments will need to understand uniqueness of unmet needs in order to strengthen family planning programmes to reduce unmet need. Studies have revealed that strong programmatic interventions not only reduce unmet need and increase contraceptive use but also increase the proportion of women using modern contraceptives [107].

#### **11. Challenges**

The challenges to family planning programmes are many, varied and require attention at the highest policy level in order to realize the huge demographic, socio-economic and development dividends of low fertility levels. This will also make SDGs achievable. Continued political will and support are prerequisite for sustainability and acceptability of FP programme:

**13. Recommendations**

**Conflict of interest**

**Author details**

Alhaji A Aliyu

**References**

needed to address unmet needs for FP.

I declare that l have no conflict of interest in writing this chapter.

Department of Community Medicine, Ahmadu Bello University, Zaria, Nigeria

Available at: http://www.africahealth2010.aed.org (Accessed 2/7/015)

www.worldwatch.org/features/population (Accessed 26/6/017)

project. Studies in Family Planning. May/June 1995;**26**(3):121-139

Medicine and Biomedical Research. 2015;**14**(2):13-21

[1] WHO/USAID. Repositioning Family Planning: Guidelines for Advocacy Action.

[3] Frederick TS. Population, Family Planning and the future of Africa. Available at: http://

[4] Binka FN, Nazzar A, Philips JF. The Navrongo community health and family planning

[5] Arends-Kuoenning M, Hossain MB, Barkat-e-Khuda. The effects of family planning workers contact on fertility preferences. Studies in Family Planning. Sep. 1999;**3**(3):183-192 [6] Aliyu AA, Shehu AU, Nasir MN, Sabitu K. Contraceptive knowledge, attitudes and practice among married women in Samaru community, Zaria-Nigeria. East African Journal of Public

[7] Bankole A, Singh S. Couples' fertility and contraceptive decision-making in developing countries: Hearing the men's voice. International Family Planning Perspective. 1998;**24**(1):15-24 [8] Aliyu AA, Dahiru T, Oyefabi AM, Ladan AM. Knowledge, determinants and use of contraceptives among married women in Sabon Gari, Zaria- northern Nigeria. Journal of

[9] Cleland J, Bernstein S, Ezeh A, Glasier A, Innis J. Family planning: The unfinished agenda.

Address all correspondence to<EMAIL_ADDRESS>
[2] World population data sheet 2016

Health. 2010;**7**(4):354-357

Lancet. 2006;**368**:1810-1827

Important shift in political commitment and priorities together with good governance, adequate funding is needed to sustain FP programmes. Efforts need to be intensified to encourage partner communication and engagement in order to improve FP practice. Further, research is

Family Planning Services in Africa: The Successes and Challenges

http://dx.doi.org/10.5772/intechopen.72224

87


**CHALLENGES IN RHEUMATOLOGY**

Edited by **Miroslav Harjacek**

**INTECHOPEN.COM**

http://dx.doi.org/10.5772/1304 Edited by Miroslav Harjacek

#### **Contributors**

Shunsei Hirohata, Yasuaki Okuda, Raquel RamĂrez Parrondo, Safa Moslemi, Laure Maneix, Karim Boumediene, Philippe Galéra, Magali Demoor, Gerardo Quintana, Paola Coral-Alvarado, Pedro Hernandez-Cortes, Juan Salvatierra Ossorio, Francisco O´Valle Ravassa, Magdalena Peregrina-Palomares, Giovanni Ciancio, Marco Bruschi, Marcello Govoni, Shikha Mittoo, Shane Shapera, Theodore Marras, Ophir Vinik, Helena Avella, Miroslav Harjacek

#### **© The Editor(s) and the Author(s) 2011**

The moral rights of the and the author(s) have been asserted.

All rights to the book as a whole are reserved by INTECH. The book as a whole (compilation) cannot be reproduced, distributed or used for commercial or non-commercial purposes without INTECH's written permission. Enquiries concerning the use of the book should be directed to INTECH rights and permissions department (permissions@intechopen.com).

Violations are liable to prosecution under the governing Copyright Law.

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#### **Notice**

Statements and opinions expressed in the chapters are these of the individual contributors and not necessarily those of the editors or publisher. No responsibility is accepted for the accuracy of information contained in the published chapters. The publisher assumes no responsibility for any damage or injury to persons or property arising out of the use of any materials, instructions, methods or ideas contained in the book.

First published in Croatia, 2011 by INTECH d.o.o. eBook (PDF) Published by IN TECH d.o.o. Place and year of publication of eBook (PDF): Rijeka, 2019. IntechOpen is the global imprint of IN TECH d.o.o. Printed in Croatia

Legal deposit, Croatia: National and University Library in Zagreb

Additional hard and PDF copies can be obtained from<EMAIL_ADDRESS>
Challenges in Rheumatology Edited by Miroslav Harjacek p. cm. ISBN 978-953-307-848-9 eBook (PDF) ISBN 978-953-51-6718-1


*1.1.2 Wheat*

Wheat is mostly used in distilleries, because it yields a mild and smooth distillate. The starch content of wheat is usually about 60%. Wheat containing more than 13% raw protein causes problems in fermentation. Wheat mashes with high protein forms foam during fermentation and the use of antifoam agent (e.g., silicone anti-foam) is necessary. **Table 1** shows the composition of key components in wheat grain and **Table 2** shows the average composition of wheat.

### **Table 1.**

*Composition of wheat components in % dry solids.*

### **Table 2.**

*Average composition of wheat.*


**3. Adaptive PID controller**

150 Frontiers of Model Predictive Control

If *A(k)* and *B(k)* are defined as expressed in equation 8, the final discrete transfer function is

( ( )) 1 ( ) 1

*tk Ak tk Bk f pk dk* ( 1) ( ) ( ) ( ) ( ( ))

For validation of the presented discrete physical model, it is necessary to have open loop data of the real system. This data has been chosen to respect two important requirements: frequency and amplitude spectrum wide enough (Psichogios & Ungar, 1992). Respecting the necessary presupposes, the collect data is made via RS232 connection to the PC. The

Figure 4 shows the physical model error signal *e(k)*, which is equal to the difference between delta and estimated delta water temperature *e(k)= Δt(k)- Δtestimated(k)*. It can be seen from this signal, that the proposed model achieved very good results with a mean square error

0 200 400<PHONE_NUMBER> 1200 1400 1600

0 200 400<PHONE_NUMBER> 1200 1400 1600

0 200 400<PHONE_NUMBER> 1200 1400 1600

0 200 400<PHONE_NUMBER> 1200 1400 1600

Time(seconds)

2

(8)

(9)

*wf k d k*

2

*B k e M wf k d k Ce*

( ( ))

*wf k d k*

( )

*Ak e M*

2

( ( ))

validation data and the physical model error are illustrated in figure 4.

given as defined in equation 9.

**2.3 Physical model validation**

0

> -5 0 5

Fig. 4. Open loop data used to validate the model.

50

100

(MSE) of 1,32ºC2 for the all test set (1 to 1600).

The first control loop tested is the adaptive proportional integral derivative control algorithm. Adaptive because we know that gain and time constant of the system changes with the input water flow. First it is described the control structure and its parameters and second the real control results are showed.

#### **3.1 Adaptive PID control structure**

This is a very simple and well known control strategy that has two control parameters *Kp* and *Kd* that are multiplied by the water flow, as illustrated in figure 6. The applied control signal is expressed in equation 10:

$$\begin{aligned} f\left(p(k)\right) &= f\left(p(k-1)\right) + wf(k)K\_p e(k) \\ &+ wf(k)K\_d(e(k) - e(k-1)) \end{aligned} \tag{10}$$

The P block gives the error proportional contribution, the *D* block gives the error derivative contribution and the *I* block gives the control signal integral contribution.

The three control parameters were adjusted after several experimental tests in controlling the real system. This algorithm has some problems dealing with time constant and time delay variations of the system. With this control loop it is not possible to define a close loop

Adaptable PID Versus Smith Predictive Control Applied to an Electric Water Heater System 153

As it was predicted the results have shown some problems in water flow variations because

The evaluation control criterion used is the mean square error (MSE). The MSE in the all test

The second control loop tested is the Smith predictive control algorithm. This control strategy is particularly used to control systems with time delay. First it is described the

The Smith predictive controller is based in the internal model controller architecture that uses the physical model presented in section II, as illustrated in figure 8. It uses two physical direct models one with time delay for the prediction loop and another with out the time

*Z -d (k)*

The Smith predictive control structure has a special configuration, because the systems has two inputs with two deferent time delays so it uses two direct models, one model with time delay for compensate its negative effect and another with out time delay needed for the

Electric Water Heater

*f(p(k-1)) hwt(k)*

*Z -1*

Physical Direct Model

*Z -1*

Physical Direct Model

Filter

control structure and its parameters and second the control results are showed.

Algorithm MSE Test Set APID 5,97

the controller just reacts when it feels an error signal different from zero.

Table 1. Mean square errors of the control results.

**4. Smith predictive controller**

**4.1 Smith predictive control structure**

*r(k) +*

*wf(k-1)*

Fig. 8. SPC constituent blocks.

internal model control structure.

*cwt(k)*

delay for the internal model control structure.

*t(k)-e(k)*

*e(k)* Model

Physical Inverse

Time Delay Function

*Z -d2 (k)*

is presented in table 1.

Fig. 6. APID controller constituent blocks.

system with a fixed time constant. The time delay is also a problem that is not solved with this control algorithm.

It was define a reference signal *r(t)* that is the desired hot water temperature and a water flow *wf(t)* with several step variations similar to the ones used in real applications. The cold water temperature was almost constant around 13,0 ºC.

For testing the controllers it can be seen that error signal *e(t)=r(t)-hwt(t)* is around zero excepted in the input transitions. In reference step variations it can be seen that the overshoots for the different water flows are similar but the rise times are clearly different, for small water flows the controller presets bigger rise times. In water flow variations the control loop have some problems because of the variable time delay. This control loop only reacted when error appears.

#### **3.2 Adaptive PID control results**

With the proposed tests signals, the tuned adaptive PID control structure was tested in controlling the electric water heater. The APID control results are shown in figure 7.

Fig. 7. Adaptive PID control results.

As it was predicted the results have shown some problems in water flow variations because the controller just reacts when it feels an error signal different from zero.

The evaluation control criterion used is the mean square error (MSE). The MSE in the all test is presented in table 1.

Table 1. Mean square errors of the control results.


*4.8. Sensory Evaluation*

A sensory evaluation of cooked mackerel fillet samples (microwave oven for six min at 60% of maximum power (Mw60)) was conducted by 25 trained panelists of staff members (aged 21–40 years) of the Department of Food Science and Technology, Faculty of Agriculture, Menofiya University, according to the method described by Allam et al. [74,77].

Panelists were selected based on their interests and availability. The panelists were asked to rate the cooked samples' color and odor using a scale point ranging from 0 to 10, where 10 = excellent; 9 = very good; 8 = good; 7 = acceptable; 6 = poor. The product was defined as unacceptable after the onset of a bad odor or unpleasant taste. The fresh mackerel fillet was used as a reference. The sensory analysis was done in three independent sessions.